Cereal crop volatile organic compound induction after mechanical injury, beetle herbivory (Oulema spp.), or fungal infection (Fusarium spp.).

PubMed

Piesik, Dariusz; Pańka, Dariusz; Delaney, Kevin J; Skoczek, Agata; Lamparski, Robert; Weaver, David K

2011-06-15

Herbivory, mechanical injury or pathogen infestation to vegetative tissues can induce volatile organic compounds (VOCs) production, which can provide defensive functions to injured and uninjured plants. In our studies with 'McNeal' wheat, 'Otana' oat, and 'Harrington' barley, plants that were mechanically injured, attacked by either of two Oulema spp. (melanopus or cyanella) beetles, or infected by one of the three Fusarium spp. (graminearum, avenaceum, or culmorum), had significant VOC induction compared to undamaged plants. Mechanical injury to the main stem or one leaf caused the induction of one green leaf volatile (GLV) - (Z)-3-hexenol, and three terpenes (β-linalool, β-caryophyllene, and α-pinene) with all three grasses; wheat and barley also showed β-linalool oxide induction. The blend of induced VOCs after Fusarium spp. infestation or Oulema spp. herbivory was dominated by GLVs ((Z)-3-hexenal, (E)-2-hexenal, (E)-2-hexenol, (Z)-3-hexenyl acetate, and 1-hexenyl acetate) and β-linalool and β-caryophyllene; beetle herbivory also induced (E)-β-farnesene. Different ratios of individual VOCs were induced between the two Oulema spp. for each cereal grass and different ratios across the three cereals for each beetle species. Also, different ratios of individual VOCs were induced between the three Fusarium spp. for each cereal grass and different ratios across the three cereals for each fungal pathogen species. Our results are preliminary since we could not simultaneously measure VOC induction from controls with each of the ten different injury treatments for each of the three cereals. However, the comparison of mechanical injury, insect herbivory, and fungal infection has not been previously examined with VOC responses from three different plant species within the same family. Also, our work suggests large qualitative and quantitative overlap of VOC induction from plants of all three cereals having beetle herbivory injury when compared to infection injury from necrotrophic fungal pathogens. Copyright © 2010 Elsevier GmbH. All rights reserved.

Behavioral responses of the diamondback moth, Plutella xylostella, to green leaf volatiles of Brassica oleracea subsp. capitata.

PubMed

Reddy, G V; Guerrero, A

2000-12-01

Green leaf volatiles (GLVs) from Brassica oleracea subsp. capitata L. have been identified as 1-hexanol, (Z)-3-hexen-1-ol, 1-hexen-3-ol, hexanal, (E)-2-hexenal, hexyl acetate, and (Z)-3-hexenyl acetate, by their mass spectra and retention times in comparison with authentic samples. No isothiocyanates were found in the extract. The activity of these chemicals has been determined on mated and unmated males and females of the diamondback moth (DBM) Plutella xylostella in the laboratory (wind tunnel) and in the field. On unmated males, mixtures of (Z)-3-hexenyl acetate, (E)-2-hexenal, and (Z)-3-hexen-1-ol with the pheromone induced attractant/arresting behavior in 80-100% of the males tested, significantly higher than the effect induced by the pheromone alone. On mated males and unmated females the effect of the GLVs alone or in combination with the pheromone was poor, while on mated females these compounds elicited upwind flight and arresting behavior in 40-60% of the females assayed. There was no synergism when these chemicals were mixed with the pheromone. In the field, (Z)-3-hexenyl acetate, the most active GLV in laboratory tests, when mixed with the pheromone in 1:1 ratio, enhanced 6-7-fold the number of females and 20-30% the number of males caught by traps over those baited with the pheromone alone. Our results indicate that the enhancement of the attraction of both males and females of the DBM to traps baited with pheromone blended with the relatively inexpensive and environmentally safe (Z)-3-hexenyl acetate may be important for future control strategies of the pest.

Aqueous oxidation of green leaf volatiles by hydroxyl radical as a source of SOA: Kinetics and SOA yields

NASA Astrophysics Data System (ADS)

Richards-Henderson, Nicole K.; Hansel, Amie K.; Valsaraj, Kalliat T.; Anastasio, Cort

2014-10-01

Green leaf volatiles (GLVs) are a class of oxygenated hydrocarbons released from vegetation, especially during mechanical stress or damage. The potential for GLVs to form secondary organic aerosol (SOA) via aqueous-phase reactions is not known. Fog events over vegetation will lead to the uptake of GLVs into water droplets, followed by aqueous-phase reactions with photooxidants such as the hydroxyl radical (OH). In order to determine if the aqueous oxidation of GLVs by OH can be a significant source of secondary organic aerosol, we studied the partitioning and reaction of five GLVs: cis-3-hexen-1-ol, cis-3-hexenyl acetate, methyl salicylate, methyl jasmonate, and 2-methyl-3-butene-2-ol. For each GLV we measured the kinetics of aqueous oxidation by OH, and the corresponding SOA mass yield. The second-order rate constants for GLVs with OH were all near diffusion controlled, (5.4-8.6) × 109 M-1 s-1 at 298 K, and showed a small temperature dependence, with an average activation energy of 9.3 kJ mol-1 Aqueous-phase SOA mass yields ranged from 10 to 88%, although some of the smaller values were not statistically different from zero. Methyl jasmonate was the most effective aqueous-phase SOA precursor due to its larger Henry's law constant and high SOA mass yield (68 ± 8%). While we calculate that the aqueous-phase SOA formation from the five GLVs is a minor source of aqueous-phase SOA, the availability of other GLVs, other oxidants, and interfacial reactions suggest that GLVs overall might be a significant source of SOA via aqueous reactions.

Development of a HS-SPME-GC/MS protocol assisted by chemometric tools to study herbivore-induced volatiles in Myrcia splendens.

PubMed

Souza Silva, Érica A; Saboia, Giovanni; Jorge, Nina C; Hoffmann, Camila; Dos Santos Isaias, Rosy Mary; Soares, Geraldo L G; Zini, Claudia A

2017-12-01

A headspace solid phase microextraction (HS-SPME) method combined with gas chromatography-mass spectrometry (GC/MS) was developed and optimized for extraction and analysis of volatile organic compounds (VOC) of leaves and galls of Myrcia splendens. Through a process of optimization of main factors affecting HS-SPME efficiency, the coating divivnilbenzene-carboxen-polydimethylsiloxane (DVB/Car/PDMS) was chosen as the optimum extraction phase, not only in terms of extraction efficiency, but also for its broader analyte coverage. Optimum extraction temperature was 30°C, while an extraction time of 15min provided the best compromise between extraction efficiencies of lower and higher molecular weight compounds. The optimized protocol was demonstrated to be capable of sampling plant material with high reproducibility, considering that most classes of analytes met the 20% RSD FDA criterion. The optimized method was employed for the analysis of three classes of M. splendens samples, generating a final list of 65 tentatively identified VOC, including alcohols, aldehydes, esters, ketones, phenol derivatives, as well as mono and sesquiterpenes. Significant differences were evident amongst the volatile profiles obtained from non-galled leaves (NGL) and leaf-folding galls (LFG) of M. splendens. Several differences pertaining to amounts of alcohols and aldehydes were detected between samples, particularly regarding quantities of green leaf volatiles (GLV). Alcohols represented about 14% of compounds detected in gall samples, whereas in non-galled samples, alcohol content was below 5%. Phenolic derived compounds were virtually absent in reference samples, while in non-galled leaves and galls their content ranged around 0.2% and 0.4%, respectively. Likewise, methyl salicylate, a well-known signal of plant distress, amounted for 1.2% of the sample content of galls, whereas it was only present in trace levels in reference samples. Chemometric analysis based on Heatmap associated with Hierarchical Cluster Analysis (HCA) and Principal Component Analysis (PCA) provided a suitable tool to differentiate VOC profiles in vegetal material, and could open new perspectives and opportunities in agricultural and ecological studies for the detection and identification of herbivore-induced plant VOC emissions. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of heat and drought stress on post-illumination bursts of volatile organic compounds in isoprene-emitting and non-emitting poplar.

PubMed

Jud, Werner; Vanzo, Elisa; Li, Ziru; Ghirardo, Andrea; Zimmer, Ina; Sharkey, Thomas D; Hansel, Armin; Schnitzler, Jörg-Peter

2016-06-01

Over the last decades, post-illumination bursts (PIBs) of isoprene, acetaldehyde and green leaf volatiles (GLVs) following rapid light-to-dark transitions have been reported for a variety of different plant species. However, the mechanisms triggering their release still remain unclear. Here we measured PIBs of isoprene-emitting (IE) and isoprene non-emitting (NE) grey poplar plants grown under different climate scenarios (ambient control and three scenarios with elevated CO2 concentrations: elevated control, periodic heat and temperature stress, chronic heat and temperature stress, followed by recovery periods). PIBs of isoprene were unaffected by elevated CO2 and heat and drought stress in IE, while they were absent in NE plants. On the other hand, PIBs of acetaldehyde and also GLVs were strongly reduced in stress-affected plants of all genotypes. After recovery from stress, distinct differences in PIB emissions in both genotypes confirmed different precursor pools for acetaldehyde and GLV emissions. Changes in PIBs of GLVs, almost absent in stressed plants and enhanced after recovery, could be mainly attributed to changes in lipoxygenase activity. Our results indicate that acetaldehyde PIBs, which recovered only partly, derive from a new mechanism in which acetaldehyde is produced from methylerythritol phosphate pathway intermediates, driven by deoxyxylulose phosphate synthase activity. © 2016 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.

GL-V9, a new synthetic flavonoid derivative, ameliorates DSS-induced colitis against oxidative stress by up-regulating Trx-1 expression via activation of AMPK/FOXO3a pathway.

PubMed

Zhao, Yue; Sun, Yang; Ding, Youxiang; Wang, Xiaoping; Zhou, Yuxin; Li, Wenjun; Huang, Shaoliang; Li, Zhiyu; Kong, Lingyi; Guo, Qinglong; Lu, Na

2015-09-22

GL-V9, a new synthesized flavonoid derivative, has been reported to possess anti-cancer properties in our previous studies. Uncontrolled overproduction of reactive oxygen species (ROS) has been implicated in oxidative damage of inflammatory bowel disease (IBD). In this study, we aimed to investigate the protective effect of GL-V9 against dextran sulfate sodium (DSS)-induced colitis. GL-V9 attenuated DSS-induced body weight loss, colon length shortening and colonic pathological damage. GL-V9 also inhibited inflammatory cells infiltration and decreased myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) activities. Moreover, GL-V9 inhibited ROS and malondialdehyde (MDA) generation, but enhanced superoxide dismutase (SOD), glutathione (GSH) and total antioxidant capacity. GL-V9 reduced pro-inflammatory cytokines production in serum and colon as well. Mechanically, GL-V9 could increase Trx-1 via activation of AMPK/FOXO3a to suppress DSS-induced colonic oxidative stress. Furthermore, GL-V9 decreased pro-inflammatory cytokines and ROS production and increased the antioxidant defenses in the mouse macrophage cells RAW264.7 by promoting Trx-1 expression. In conclusion, our study demonstrated that GL-V9 attenuated DSS-induced colitis against oxidative stress by up-regulating Trx-1 via activation of AMPK/FOXO3a pathway, suggesting that GL-V9 might be a potential effective drug for colitis.

Advanced Hybrid Materials for Aerospace Propulsion Applications (Briefing Charts)

DTIC Science & Technology

2013-02-01

72.1 mN/m Hexadecane, gLV = 27.5 mN/m Previous research suggests that the superhydrophobicity of the lotus leaf is related to the low surface...distribution unlimited. 6 Non-wetting surfaces Superhydrophilic Hydrophilic Hydrophobic Superhydrophobic 24.00° 115.60° θ ~ 0° 0°< θ < 90° θ > 90° θ...First major research efforts: 2007-2010 Superhydrophobic coatings with ៀ kPa ice adhesion demonstrated in laboratory, moderately competitive

Studies in search of selective detection of isomeric biogenic hexen-1-ols and hexanal by flowing afterglow tandem mass spectrometry using [H3O]+ and [NO]+ reagent ions.

PubMed

Dhooghe, Frederik; Vansintjan, Robbe; Schoon, Niels; Amelynck, Crist

2012-08-30

Plants emit a blend of oxygenated volatile C(6) compounds, known as green leaf volatiles (GLVs), in response to leaf tissue damage related to stress conditions. On-line chemical ionization mass spectrometry (CI-MS) techniques have often been used to study the dynamics of these emissions but they fail to selectively detect some important GLV compounds. A flowing afterglow tandem mass spectrometer (FA-TMS) was used to investigate the feasibility of selective on-line detection of isomeric hexen-1-ols and hexanal. Product ions at m/z 101 and 83 from chemical ionization (CI) of these compounds by [H(3)O](+), and product ions at m/z 100, 99, 83, 82 and 72 from CI by [NO](+), have been subjected to collision-induced dissociation (CID) in the collision cell of the TMS at center-of-mass energies ranging between 0 and 9 eV. CID of product ions at m/z 101 and 83 from CI of GLVs with [H(3)O](+) and of product ions at m/z 83, 82 and 72 from CI of GLVs with [NO](+) resulted in identical fragmentation patterns for all measured compounds, ruling out any selectivity. However, CID of product ions at m/z 100 and 99 from CI by [NO](+) led to CID product ions with abundances differing largely between the compounds, allowing the fast selective detection of 2-hexen-1-ols, 3-hexen-1-ols and hexanal with a chosen accuracy within a well-defined range of relative concentrations. This research illustrates that, in contrast to common CI-MS techniques, FA-TMS allows the selective detection of hexanal in a mixture of hexanal and hexen-1-ols with a chosen accuracy for a well-defined range of relative concentrations and represents a step forward in the search for selective detection of GLVs in CI-TMS. Copyright © 2012 John Wiley & Sons, Ltd.

Structural Insights Into the Evolutionary Paths of Oxylipin Biosynthetic Enzymes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, D.-S.; Nioche, P.; Hamberg, M.

2009-05-20

The oxylipin pathway generates not only prostaglandin-like jasmonates but also green leaf volatiles (GLVs), which confer characteristic aromas to fruits and vegetables. Although allene oxide synthase (AOS) and hydroperoxide lyase are atypical cytochrome P450 family members involved in the synthesis of jasmonates and GLVs, respectively, it is unknown how these enzymes rearrange their hydroperoxide substrates into different products. Here we present the crystal structures of Arabidopsis thaliana AOS, free and in complex with substrate or intermediate analogues. The structures reveal an unusual active site poised to control the reactivity of an epoxyallylic radical and its cation by means of interactionsmore » with an aromatic {pi}-system. Replacing the amino acid involved in these steps by a non-polar residue markedly reduces AOS activity and, unexpectedly, is both necessary and sufficient for converting AOS into a GLV biosynthetic enzyme. Furthermore, by combining our structural data with bioinformatic and biochemical analyses, we have discovered previously unknown hydroperoxide lyase in plant growth-promoting rhizobacteria, AOS in coral, and epoxyalcohol synthase in amphioxus. These results indicate that oxylipin biosynthetic genes were present in the last common ancestor of plants and animals, but were subsequently lost in all metazoan lineages except Placozoa, Cnidaria and Cephalochordata.« less

Technological processes of grating light valve as diffractive spatial light modulator in laser phototypesetting system

NASA Astrophysics Data System (ADS)

Zhang, Wei; Geng, Yu; Hou, Changlun; Yang, Guoguang; Bai, Jian

2008-11-01

Grating Light Valve (GLV) is a kind of optics device based on Micro-Opto-Electro-Mechanical System (MOEMS) technology, utilizing diffraction principle to switch, attenuate and modulate light. In this paper, traditional GLV device's structure and its working principle are illuminated, and a kind of modified GLV structure is presented, with details introduction of the fabrication technology. The GLV structure includes single crystal silicon substrate, silicon dioxide isolating layer, aluminum layer of fixed ribbons and silicon nitride of movable ribbons. In the fabrication, lots of techniques are adopted, such as low-pressure chemical vapor deposition (LPCVD), photolithography, etching and evaporation. During the fabrication processes, Photolithography is a fundamental and fatal technology, which determines etching result and GLV quality. Some methods are proposed through repeated experiments, to improve etching result greatly and guide the practical application. This kind of GLV device can be made both small and inexpensively, and has been tested to show proper range of actuation under DC bias, with good performance. The GLV device also has merits such as low cost, simple technology, high fill ratio and low driving voltage. It can properly be well used and match the demands of high light power needed in laser phototypesetting system, as a high-speed, high-resolution light modulator.

Preclinical Testing Oncolytic Vaccinia Virus Strain GLV-5b451 Expressing an Anti-VEGF Single-Chain Antibody for Canine Cancer Therapy

PubMed Central

Adelfinger, Marion; Bessler, Simon; Frentzen, Alexa; Cecil, Alexander; Langbein-Laugwitz, Johanna; Gentschev, Ivaylo; Szalay, Aladar A.

2015-01-01

Virotherapy on the basis of oncolytic vaccinia virus (VACV) strains is a novel approach for canine cancer therapy. Here we describe, for the first time, the characterization and the use of VACV strain GLV-5b451 expressing the anti-vascular endothelial growth factor (VEGF) single-chain antibody (scAb) GLAF-2 as therapeutic agent against different canine cancers. Cell culture data demonstrated that GLV-5b451 efficiently infected and destroyed all four tested canine cancer cell lines including: mammary carcinoma (MTH52c), mammary adenoma (ZMTH3), prostate carcinoma (CT1258), and soft tissue sarcoma (STSA-1). The GLV-5b451 virus-mediated production of GLAF-2 antibody was observed in all four cancer cell lines. In addition, this antibody specifically recognized canine VEGF. Finally, in canine soft tissue sarcoma (CSTS) xenografted mice, a single systemic administration of GLV-5b451 was found to be safe and led to anti-tumor effects resulting in the significant reduction and substantial long-term inhibition of tumor growth. A CD31-based immuno-staining showed significantly decreased neo-angiogenesis in GLV-5b451-treated tumors compared to the controls. In summary, these findings indicate that GLV-5b451 has potential for use as a therapeutic agent in the treatment of CSTS. PMID:26205404

Gene Therapy Using Therapeutic and Diagnostic Recombinant Oncolytic Vaccinia Virus GLV-1h153 for Management of Colorectal Peritoneal Carcinomatosis

PubMed Central

Eveno, Clarisse; Mojica, Kelly; Ady, Justin W.; Thorek, Daniel L.J.; Longo, Valerie; Belin, Laurence J.; Gholami, Sepideh; Johnsen, Clark; Zanzonico, Pat; Chen, Nanhai; Yu, Tony; Szalay, Aladar A.; Fong, Yuman

2015-01-01

Background Peritoneal carcinomatosis (PC) is a terminal progression of colorectal cancer (CRC). Poor response to cytoreductive surgery and chemotherapy, coupled with the inability to reliably track disease progression using established diagnostic methods make this a deadly disease. This paper examines the effectiveness of the oncolytic vaccinia virus GLV-1h153 as a therapeutic and diagnostic vehicle. We believe that viral expression of the human sodium iodide transporter (hNIS) can provide both real-time monitoring of viral therapy and effective treatment of colorectal peritoneal carcinomatosis (CRPC). Methods Infectivity and cytotoxic effect of GLV-1h153 on CRC cell lines was assayed in-vitro. Viral replication was examined by standard viral plaque assays. Orthotopic CRPC xenografts were generated in athymic nude mice, and subsequently administered GLV-1h153 intraperitoneally. Reduction of tumor burden was assessed by mass. Orthotopic tumors were visualized by SPECT/CT after Iodine (131I) administration and by fluorescence optical imaging. Results GLV-1h153 infected and killed CRC cells in a time and concentration dependent manner. Viral replication demonstrated greater than a 2.35 log increase in titer over 4 days. Intraperitoneal treatment of orthotopic CRPC xenografts resulted in a significant reduction of tumor burden. Infection of orthotopic xenografts was both therapeutic and facilitated monitoring by 131I-SPECT/CT via expression of hNIS in infected tissue. Conclusions GLV-1h153 effectively kills CRC in-vitro and dramatically reduces tumor burden in-vivo. We demonstrate that GLV-1h153 can be used as an agent to provide accurate delineation of tumor burden in-vivo. These findings indicate that GLV-1h153 has significant potential for use as theragnostic agent in the treatment of CRPC. PMID:25616946

Engineering of Escherichia coli to facilitate efficient utilization of isomaltose and panose in industrial glucose feedstock.

PubMed

Abe, Kenji; Kuroda, Akio; Takeshita, Ryo

2017-03-01

Industrial glucose feedstock prepared by enzymatic digestion of starch typically contains significant amounts of disaccharides such as maltose and isomaltose and trisaccharides such as maltotriose and panose. Maltose and maltosaccharides can be utilized in Escherichia coli fermentation using industrial glucose feedstock because there is an intrinsic assimilation pathway for these sugars. However, saccharides that contain α-1,6 bonds, such as isomaltose and panose, are still present after fermentation because there is no metabolic pathway for these sugars. To facilitate more efficient utilization of glucose feedstock, we introduced glvA, which encodes phospho-α-glucosidase, and glvC, which encodes a subunit of the phosphoenolpyruvate-dependent maltose phosphotransferase system (PTS) of Bacillus subtilis, into E. coli. The heterologous expression of glvA and glvC conferred upon the recombinant the ability to assimilate isomaltose and panose. The recombinant E. coli assimilated not only other disaccharides but also trisaccharides, including alcohol forms of these saccharides, such as isomaltitol. To the best of our knowledge, this is the first report to show the involvement of the microbial PTS in the assimilation of trisaccharides. Furthermore, we demonstrated that an L-lysine-producing E. coli harboring glvA and glvC converted isomaltose and panose to L-lysine efficiently. These findings are expected to be beneficial for industrial fermentation.

Pinot noir wine volatile and anthocyanin composition under different levels of vine fruit zone leaf removal.

PubMed

Feng, Hui; Skinkis, Patricia A; Qian, Michael C

2017-01-01

The impacts of fruit zone leaf removal on volatile and anthocyanin compositions of Pinot noir wine were investigated over two growing seasons. Wine volatiles were analyzed by multiple techniques, including headspace solid phase microextraction-GC-MS (HS-SPME-GC-MS), headspace-GC-FID (HS-GC-FID) and stir bar sorptive extraction-GC-MS (SBSE-GC-MS). Fruit zone leaf removal affected the concentration of many grape-derived volatile compounds such as terpene alcohols and C13-norisoprenoids in wine, although the degree of impact depended on the vintage year and severity of leaf removal. Fruit zone leaf removal resulted in greater concentrations of linalool, α-terpineol and β-damascenone but had no impact on other terpene alcohols or β-ionone. Fruit zone leaf removal had no consistent impact on C6 alcohols, volatile phenols, lactones, fermentation-derived alcohols, acids, or most esters. Fruit zone leaf removal increased anthocyanins in final wine. Copyright © 2016 Elsevier Ltd. All rights reserved.

Isolation and characterization of allelopathic volatiles from mugwort (Artemisia vulgaris).

PubMed

Barney, Jacob N; Hay, Anthony G; Weston, Leslie A

2005-02-01

Several volatile allelochemicals were identified and characterized from fresh leaf tissue of three distinct populations of the invasive perennial weed, mugwort (Artemisia vulgaris). A unique bioassay was used to demonstrate the release of volatile allelochemicals from leaf tissues. Leaf volatiles were trapped and analyzed via gas chromatography coupled with mass spectrometry. Some of the components identified were terpenes, including camphor, eucalyptol, alpha-pinene, and beta-pinene. Those commercially available were tested individually to determine their phytotoxicity. Concentrations of detectable volatiles differed in both absolute and relative proportions among the mugwort populations. The three mugwort populations consisted of a taller, highly branched population (ITH-1); a shorter, lesser-branched population (ITH-2) (both grown from rhizome fragments from managed landscapes); and a population grown from seed with lobed leaves (VT). Considerable interspecific variation existed in leaf morphology and leaf surface chemistry. Bioassays revealed that none of the individual monoterpenes could account for the observed phytotoxicity imparted by total leaf volatiles, suggesting a synergistic effect or activity of a component not tested. Despite inability to detect a single dominant phytotoxic compound, decreases in total terpene concentration with increase in leaf age correlated with decreases in phytotoxicity. The presence of bioactive terpenoids in leaf surface chemistry of younger mugwort tissue suggests a potential role for terpenoids in mugwort establishment and proliferation in introduced habitats.

The Medial Ventrothalamic Circuitry: Cells Implicated in a Bimodal Network

PubMed Central

Vega-Zuniga, Tomas; Trost, Dominik; Schicker, Katrin; Bogner, Eva M.; Luksch, Harald

2018-01-01

Previous avian thalamic studies have shown that the medial ventral thalamus is composed of several nuclei located close to the lateral wall of the third ventricle. Although the general connectivity is known, detailed morphology and connectivity pattern in some regions are still elusive. Here, using the intracellular filling technique in the chicken, we focused on two neural structures, namely, the retinorecipient neuropil of the n. geniculatus lateralis pars ventralis (GLv), and the adjacent n. intercalatus thalami (ICT). We found that the GLv-ne cells showed two different neuronal types: projection cells and horizontal interneurons. The projection cells showed variable morphologies and dendritic arborizations with axons that targeted the n. lentiformis mesencephali (LM), griseum tectale (GT), ICT, n. principalis precommissuralis (PPC), and optic tectum (TeO). The horizontal cells showed a widespread mediolateral neural process throughout the retinorecipient GLv-ne. The ICT cells, on the other hand, had multipolar somata with wide dendritic fields that extended toward the lamina interna of the GLv, and a projection pattern that targeted the n. laminaris precommissuralis (LPC). Together, these results elucidate the rich complexity of the connectivity pattern so far described between the GLv, ICT, pretectum, and tectum. Interestingly, the implication of some of these neural structures in visuomotor and somatosensory roles strongly suggests that the GLv and ICT are part of a bimodal circuit that may be involved in the generation/modulation of saccades, gaze control, and space perception. PMID:29479309

Volatile components of vine leaves from two Portuguese grape varieties (Vitis vinifera L.), Touriga Nacional and Tinta Roriz, analysed by solid-phase microextraction.

PubMed

Fernandes, Bruno; Correia, Ana C; Cosme, Fernanda; Nunes, Fernando M; Jordão, António M

2015-01-01

The purpose of this work was to study the volatile composition of vine leaves and vine leaf infusion prepared from vine leaves collected at 30 and 60 days after grape harvest of two Vitis vinifera L. species. Eighteen volatile compounds were identified by gas chromatography-mass spectrometry in vine leaves and in vine leaf infusions. It was observed that the volatile compounds present in vine leaves are dependent on the time of harvest, with benzaldehyde being the major volatile present in vine leaves collected at 30 days after harvesting. There are significant differences in the volatile composition of the leaves from the two grape cultivars, especially in the sample collected at 60 days after grape harvest. This is not reflected in the volatile composition of the vine leaf infusion made from this two cultivars, the more important being the harvesting date for the volatile profile of vine leaf infusion than the vine leaves grape cultivar.

Social dimensions related to anaemia among women of childbearing age from rural India.

PubMed

Rao, Shobha; Joshi, Smita; Bhide, Pradnya; Puranik, Bhairavi; Kanade, Asawari

2011-02-01

To examine various sociodemographic aspects related to consumption of micronutrient-rich foods like green leafy vegetables (GLV), which will be helpful in modifying dietary habits, a strategy that merits consideration for prevention of anaemia. Cross-sectional study for collecting data on socio-economic and anthropometric (weight, height) variables, Hb, dietary pattern (FFQ) and peripheral smear examination for classifying nutritional and iron-deficiency anaemia (IDA). Three villages near Pune city, Maharashtra, India. Rural women (n 418) of childbearing age (15-35 years). Mean Hb was 11·07 g/dl. Seventy-seven per cent of the women were anaemic (Hb < 12 g/dl) and 28 % had IDA, indicating that a large proportion of the women had nutritional anaemia. Higher prevalence of IDA was associated with several sociodemographic and maternal parameters, but multiple logistic regression analysis showed significant (P < 0·05) risk of IDA with lower body weight (<40 kg), short maternal height (<145 cm), younger age at marriage (<19 years) and higher parity (≥ 2). Various socio-cultural reasons associated with low consumption of GLV included non-cultivation of GLV, priority for selling them rather than home consumption, dislike of GLV by husband and children, and lack of awareness about different recipes for GLV. Our findings highlight that low consumption of GLV, which are treasures of micronutrients including Fe, is associated with genuine social reasons. This indicates a need for developing action programmes to improve nutritional knowledge and awareness leading to enhanced consumption of Fe-rich foods for preventing anaemia in rural India.

Microconnectomics of the pretectum and ventral thalamus in the chicken (Gallus gallus).

PubMed

Vega-Zuniga, Tomas; Marín, Gonzalo; González-Cabrera, Cristian; Planitscher, Eva; Hartmann, Anja; Marks, Vanessa; Mpodozis, Jorge; Luksch, Harald

2016-08-01

The avian pretectal and ventrothalamic nuclei, encompassing the griseum tectale (GT), n. lentiformis mesencephali (LM), and n. geniculatus lateralis pars ventralis (GLv), are prominent retinorecipient structures related to optic flow operations and visuomotor control. Hence, a close coordination of these neural circuits is to be expected. Yet the connectivity among these nuclei is poorly known. Here, using intracellular labeling and in situ hybridization, we investigated the detailed morphology, connectivity, and neurochemical identity of neurons in these nuclei. Two different cell types exist in the GT: one that generates an axonal projection to the optic tectum (TeO), LM, GLv, and n. intercalatus thalami (ICT), and a second population that only projects to the LM and GLv. In situ hybridization revealed that most neurons in the GT express the vesicular glutamate transporter (VGluT2) mRNA, indicating a glutamatergic identity. In the LM, three morphological cell types were defined, two of which project axons towards dorsal targets. The LM neurons showed strong VGluT2 expression. Finally, the cells located in the GLv project to the TeO, LM, GT, n. principalis precommisuralis (PPC), and ICT. All neurons in the GLv showed strong expression of the vesicular inhibitory amino acid transporter (VIAAT) mRNA, suggesting a GABAergic identity. Our results show that the pretectal and ventrothalamic nuclei are highly interconnected, especially by glutamatergic and GABAergic neurons from the GT and GLv, respectively. This complex morphology and connectivity might be required to organize orienting visuomotor behaviors and coordinate the specific optic flow patterns that they induce. J. Comp. Neurol. 524:2208-2229, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Lotka-Volterra representation of general nonlinear systems.

PubMed

Hernández-Bermejo, B; Fairén, V

1997-02-01

In this article we elaborate on the structure of the generalized Lotka-Volterra (GLV) form for nonlinear differential equations. We discuss here the algebraic properties of the GLV family, such as the invariance under quasimonomial transformations and the underlying structure of classes of equivalence. Each class possesses a unique representative under the classical quadratic Lotka-Volterra form. We show how other standard modeling forms of biological interest, such as S-systems or mass-action systems, are naturally embedded into the GLV form, which thus provides a formal framework for their comparison and for the establishment of transformation rules. We also focus on the issue of recasting of general nonlinear systems into the GLV format. We present a procedure for doing so and point at possible sources of ambiguity that could make the resulting Lotka-Volterra system dependent on the path followed. We then provide some general theorems that define the operational and algorithmic framework in which this is not the case.

Vaccinia Virus-mediated Expression of Human Erythropoietin in Tumors Enhances Virotherapy and Alleviates Cancer-related Anemia in Mice

PubMed Central

Nguyen, Duong H; Chen, Nanhai G; Zhang, Qian; Le, Ha T; Aguilar, Richard J; Yu, Yong A; Cappello, Joseph; Szalay, Aladar A

2013-01-01

Recombinant human erythropoietin (rhEPO), a glycoprotein hormone regulating red blood cell (RBC) formation, is used for the treatment of cancer-related anemia. The effect of rhEPO on tumor growth, however, remains controversial. Here, we report the construction and characterization of the recombinant vaccinia virus (VACV) GLV-1h210, expressing hEPO. GLV-1h210 was shown to replicate in and kill A549 lung cancer cells in culture efficiently. In mice bearing A549 lung cancer xenografts, treatment with a single intravenous dose of GLV-1h210 resulted in tumor-specific production and secretion of functional hEPO, which exerted an effect on RBC progenitors and precursors in the mouse bone marrow, leading to a significant increase in the number of RBCs and in the level of hemoglobin. Furthermore, virally expressed hEPO, but not exogenously added rhEPO, enhanced virus-mediated green fluorescent protein (GFP) expression in tumors and subsequently accelerated tumor regression when compared with the treatment with the parental virus GLV-1h68 or GLV-1h209 that expressed a nonfunctional hEPO protein. Moreover, intratumorally expressed hEPO caused enlarged tumoral microvessels, likely facilitating virus spreading. Taken together, VACV-mediated intratumorally expressed hEPO not only enhanced oncolytic virotherapy but also simultaneously alleviated cancer-related anemia. PMID:23765443

Trapping female Pandemis limitata (Lepidoptera: Tortricidae) moths with mixtures of acetic acid, benzenoid apple leaf volatiles, and sex pheromones

USDA-ARS?s Scientific Manuscript database

Pandemis limitata (Robinson) is one of several leaf-feeding caterpillar pests of commercial tree-fruit crops in British Columbia. Recent discovery that European Pandemis spp. are attracted to lures containing acetic acid (AA) and caterpillar-induced benzenoid apple leaf volatiles, 2-phenylethanol a...

Bidirectional exchange of biogenic volatiles with vegetation: emission sources, reactions, breakdown and deposition

PubMed Central

Niinemets, Ülo; Fares, Silvano; Harley, Peter; Jardine, Kolby J.

2014-01-01

Biogenic volatile organic compound (BVOC) emissions are widely modeled as inputs to atmospheric chemistry simulations. However, BVOC may interact with cellular structures and neighboring leaves in a complex manner during volatile diffusion from the sites of release to leaf boundary layer and during turbulent transport to the atmospheric boundary layer. Furthermore, recent observations demonstrate that the BVOC emissions are bidirectional, and uptake and deposition of BVOC and their oxidation products are the rule rather than the exception. This review summarizes current knowledge of within-leaf reactions of synthesized volatiles with reactive oxygen species (ROS), uptake, deposition and storage of volatiles and their oxidation products as driven by adsorption on leaf surface and solubilization and enzymatic detoxification inside leaves. The available evidence indicates that due to reactions with ROS and enzymatic metabolism, the BVOC gross production rates are much larger than previously thought. The degree to which volatiles react within leaves and can be potentially taken up by vegetation depends on compound reactivity, physicochemical characteristics, as well as their participation in leaf metabolism. We argue that future models should be based on the concept of bidirectional BVOC exchange and consider modification of BVOC sink/source strengths by within-leaf metabolism and storage. PMID:24635661

Comparison of male and female emerald ash borer (Coleoptera: Buprestidae) responses to phoebe oil and (Z)-3-hexenol lures in light green prism traps.

PubMed

Grant, Gary G; Poland, Therese M; Ciaramitaro, Tina; Lyons, D Barry; Jones, Gene C

2011-02-01

We conducted trapping experiments for the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) in Michigan, U.S.A., and Ontario, Canada, to compare unbaited light green sticky prism traps with traps baited with phoebe oil, (Z)-3-hexenol (Z3-6:OH), or blends of other green leaf volatiles (GLVs) with Z3-6:OH. Traps were placed in the lower canopy of ash trees (Fraxinus spp.). Catches with Z3-6:OH-baited traps showed a significant male bias and these traps caught significantly more males than the unbaited controls at both sites. They were also superior to phoebe oil-baited traps and those baited with GLV blends. Catches with phoebe oil showed a significant female bias but there was no difference in the number of females captured between traps baited with phoebe oil or Z3-6:OH lures. Catches were analyzed at regular time intervals to examine the response of A. planipennis to the lures over the course of the flight season. Z3-6:OH-baited traps consistently caught more males than the controls at each interval throughout the flight season. Catches of females with Z3-6:OH and phoebe oil were significantly better than the controls early in the flight season but declined to control levels by midseason. Our results suggest that Z3-6:OH-baited green traps placed in the ash canopy would be a superior lure for detecting and monitoring A. planipennis throughout the flight season.

Does Enzymatic Hydrolysis of Glycosidically Bound Volatile Compounds Really Contribute to the Formation of Volatile Compounds During the Oolong Tea Manufacturing Process?

PubMed

Gui, Jiadong; Fu, Xiumin; Zhou, Ying; Katsuno, Tsuyoshi; Mei, Xin; Deng, Rufang; Xu, Xinlan; Zhang, Linyun; Dong, Fang; Watanabe, Naoharu; Yang, Ziyin

2015-08-12

It was generally thought that aroma of oolong tea resulted from hydrolysis of glycosidically bound volatiles (GBVs). In this study, most GBVs showed no reduction during the oolong tea manufacturing process. β-Glycosidases either at protein or gene level were not activated during the manufacturing process. Subcellular localization of β-primeverosidase provided evidence that β-primeverosidase was located in the leaf cell wall. The cell wall remained intact during the enzyme-active manufacturing process. After the leaf cell disruption, GBV content was reduced. These findings reveal that, during the enzyme-active process of oolong tea, nondisruption of the leaf cell walls resulted in impossibility of interaction of GBVs and β-glycosidases. Indole, jasmine lactone, and trans-nerolidol were characteristic volatiles produced from the manufacturing process. Interestingly, the contents of the three volatiles was reduced after the leaf cell disruption, suggesting that mechanical damage with the cell disruption, which is similar to black tea manufacturing, did not induce accumulation of the three volatiles. In addition, 11 volatiles with flavor dilution factor ≥4(4) were identified as relatively potent odorants in the oolong tea. These results suggest that enzymatic hydrolysis of GBVs was not involved in the formation of volatiles of oolong tea, and some characteristic volatiles with potent odorants were produced from the manufacturing process.

Dock leaf beetle, Gastrophysa viridula Deg., herbivory on Mossy Sorrel, Rumex confertus Willd: Induced plant volatiles and beetle orientation responses

USDA-ARS?s Scientific Manuscript database

The invasive weed Rumex confertus Willd. (mossy sorrel) is fed upon and severely defoliated by Gastrophysa viridula Deg. (dock leaf beetle), a highly promising biological control agent for this weed. We report volatile organic compound (VOC) induction when one leaf on R. confertus was damaged by G. ...

Characterization of polar organosulfates in secondary organic aerosol from the unsaturated aldehydes 2-E-pentenal, 2-E-hexenal, and 3-Z-hexenal

NASA Astrophysics Data System (ADS)

Safi Shalamzari, Mohammad; Vermeylen, Reinhilde; Blockhuys, Frank; Kleindienst, Tadeusz E.; Lewandowski, Michael; Szmigielski, Rafal; Rudzinski, Krzysztof J.; Spólnik, Grzegorz; Danikiewicz, Witold; Maenhaut, Willy; Claeys, Magda

2016-06-01

We show in the present study that the unsaturated aldehydes 2-E-pentenal, 2-E-hexenal, and 3-Z-hexenal are biogenic volatile organic compound (BVOC) precursors for polar organosulfates with molecular weights (MWs) 230 and 214, which are also present in ambient fine aerosol from a forested site, i.e., K-puszta, Hungary. These results complement those obtained in a previous study showing that the green leaf aldehyde 3-Z-hexenal serves as a precursor for MW 226 organosulfates. Thus, in addition to isoprene, the green leaf volatiles (GLVs) 2-E-hexenal and 3-Z-hexenal, emitted due to plant stress (mechanical wounding or insect attack), and 2-E-pentenal, a photolysis product of 3-Z-hexenal, should be taken into account for secondary organic aerosol and organosulfate formation. Polar organosulfates are of climatic relevance because of their hydrophilic properties and cloud effects. Extensive use was made of organic mass spectrometry (MS) and detailed interpretation of MS data (i.e., ion trap MS and accurate mass measurements) to elucidate the chemical structures of the MW 230, 214 and 170 organosulfates formed from 2-E-pentenal and indirectly from 2-E-hexenal and 3-Z-hexenal. In addition, quantum chemical calculations were performed to explain the different mass spectral behavior of 2,3-dihydroxypentanoic acid sulfate derivatives, where only the isomer with the sulfate group at C-3 results in the loss of SO3. The MW 214 organosulfates formed from 2-E-pentenal are explained by epoxidation of the double bond in the gas phase and sulfation of the epoxy group with sulfuric acid in the particle phase through the same pathway as that proposed for 3-sulfooxy-2-hydroxy-2-methylpropanoic acid from the isoprene-related α,β-unsaturated aldehyde methacrolein in previous work (Lin et al., 2013). The MW 230 organosulfates formed from 2-E-pentenal are tentatively explained by a novel pathway, which bears features of the latter pathway but introduces an additional hydroxyl group at the C-4 position. Evidence is also presented that the MW 214 positional isomer, 2-sulfooxy-3-hydroxypentanoic acid, is unstable and decarboxylates, giving rise to 1-sulfooxy-2-hydroxybutane, a MW 170 organosulfate. Furthermore, evidence is obtained that lactic acid sulfate is generated from 2-E-pentenal. This chemistry could be important on a regional and local scale where GLV emissions such as from grasses and cereal crops are substantial.

Green leaf volatiles disrupt responses by the spruce beetle, Dendroctonus rufipennis, and the western pine beetle, Dendroctonus brevicomis (Coleoptera: Scolytidae) to attractant-baited traps

Treesearch

Therese M. Poland; J. H. Borden; A. J. Stock; L. J. Chong

1998-01-01

We tested the hypothesis that green leaf volatiles (GLVs) disrupt the response of spruce beetles, Dendroctonus rufipennis Kirby, and western pine beetles, Dendroctonus brevicomis LeConte, to attraetant-baited traps. Two green leaf aldehydes, hexanal and (E)-2-hexenal, reduced the number of spruce beetles captured...

Secretory cavities and volatiles of Myrrhinium atropurpureum Schott var. atropurpureum (Myrtaceae): an endemic species collected in the restingas of Rio de Janeiro, Brazil.

PubMed

Victório, Cristiane Pimentel; Moreira, Claudio B; Souza, Marcelo da Costa; Sato, Alice; Arruda, Rosani do Carmo de Oliveira

2011-07-01

In this study, we investigated the leaf anatomy and the composition of volatiles in Myrrhinium atropurpureum var. atropurpureum endemic to Rio de Janeiro restingas. Particularly, leaf secretory structures were described using light microscopy, and histochemical tests were performed from fresh leaves to localize the secondary metabolites. To observe secretory cavities, fixed leaf samples were free-hand sectioned. To evaluate lipophilic compounds and terpenoids the following reagents were employed: Sudans III and IV, Red oil O and Nile blue. Leaf volatiles were characterized by gas chromatography after hydrodistillation (HD) or simultaneous distillation-extraction (SDE). Leaf analysis showed several cavities in mesophyll that are the main sites of lipophilic and terpenoid production. Monoterpenes, which represented more than 80% of the major volatiles, were characterized mainly by alpha- and beta-pinene and 1,8-cineole. In order to provide tools for M. atropurpureum identification, the following distinguishing characteristics were revealed by the following data: 1) adaxial face clear and densely punctuated by the presence of round or ellipsoidal secretory cavities randomly distributed in the mesophyll; 2) the presence of cells overlying the upper neck cells of secretory cavities; 3) the presence of numerous paracytic stomata distributed on the abaxial leaf surface, but absent in vein regions and leaf margin; and 4) non-glandular trichomes on both leaf surfaces. Our study of the compounds produced by the secretory cavities of M. atropurpureum led us to conclude that volatile terpenoid class are the main secretory compounds and that they consist of a high concentration of monoterpenes, which may indicate the phytotherapeutic importance of this plant.

A volatile trail Pheromone of the Leaf-Cutting Ant, Atta Texana

Treesearch

J. H. Tumlinson; John C. Moser; R. M. Silverstein; R. G. Brownlee; J. M. Ruth

1972-01-01

The major volatile trail-marking pheromone of the Texas leaf-cutting Ant, Atta texana, was isolated, identified as methyl 4-methylpyrrole-2-carboxylate, and synthesized. The synthesized pheromone elicited strong trail-following response from workers in the laboratory and field.

Sulfur volatiles in guava (Psidium guajava L.) leaves: possible defense mechanism.

PubMed

Rouseff, Russell L; Onagbola, Ebenezer O; Smoot, John M; Stelinski, Lukasz L

2008-10-08

Volatiles from crushed and intact guava leaves (Psidium guajava L.) were collected using static headspace SPME and determined using GC-PFPD, pulsed flame photometric detection, and GC-MS. Leaf volatiles from four common citrus culitvars were examined similarly to determine the potential component(s) responsible for guava's protective effect against the Asian citrus psyllid (Diaphorina citri Kuwayama), which is the insect vector of Huanglongbing (HLB) or citrus greening disease. Seven sulfur volatiles were detected: hydrogen sulfide, sulfur dioxide, methanethiol, dimethyl sulfide (DMS), dimethyl disulfide (DMDS), methional, and dimethyl trisulfide (DMTS). Identifications were based on matching linear retention index values on ZB-5, DB-Wax, and PLOT columns and MS spectra in the case of DMDS and DMS. DMDS is an insect toxic, defensive volatile produced only by wounded guava but not citrus leaves and, thus, may be the component responsible for the protective effect of guava against the HLB vector. DMDS is formed immediately after crushing, becoming the major headspace volatile within 10 min. Forty-seven additional leaf volatiles were identified from LRI and MS data in the crushed guava leaf headspace.

The leaf volatile constituents of Isatis tinctoria by Solid-Phase Microextraction and Gas chromatography/Mass Spectrometry.

PubMed

Condurso, Cettina; Verzera, Antonella; Romeo, Vincenza; Ziino, Marisa; Trozzi, Alessandra; Ragusa, Salvatore

2006-08-01

The leaf volatile constituents of Isatis tinctoria L. (Brassicaceae) have been studied by Solid-Phase Microextraction and Gas chromatography/Mass Spectrometry (SPME/GC-MS). Seventy components were fully characterized by mass spectra, linear retention indices, and injection of standards; the average composition (ppm) as single components and classes of substances is reported. Aliphatic hydrocarbons, acids, alcohols, aldehydes and esters, aromatic aldehydes, esters and ethers, furans, isothiocyanates and thiocyanates, sulfurated compounds, nitriles, terpenes and sesquiterpenes were identified. Leaf volatiles in Isatis tinctoria L. were characterized by a high amount of isothiocyanates which accounted for about 40 % of the total volatile fraction. Isothiocyanates are important and characteristic flavour compounds in Brassica vegetables and the cancer chemo-protective attributes are recently responsible for their growing interest.

A comparison of chemical, antioxidant and antimicrobial studies of cinnamon leaf and bark volatile oils, oleoresins and their constituents.

PubMed

Singh, Gurdip; Maurya, Sumitra; DeLampasona, M P; Catalan, Cesar A N

2007-09-01

The antioxidant, antifungal and antibacterial potentials of volatile oils and oleoresin of Cinnamomum zeylanicum Blume (leaf and bark) were investigated in the present study. The oleoresins have shown excellent activity for the inhibition of primary and secondary oxidation products in mustard oil added at the concentration of 0.02% which were evaluated using peroxide, thiobarbituric acid, p-anisidine and carbonyl values. Moreover, it was further supported by other complementary antioxidant assays such as ferric thiocyanate method in linoleic acid system, reducing power, chelating and scavenging effects on 1,1'-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals. In antimicrobial investigations, using inverted petriplate and food poison techniques, the leaf and bark volatile oils has been found to be highly effective against all the tested fungi except Aspergillus ochraceus. However, leaf oleoresin has shown inhibition only for Penicillium citrinum whereas bark oleoresin has caused complete mycelial zone inhibition for Aspergillus flavus and A. ochraceus along with Aspergillus niger, Aspergillus terreus, P. citrinum and Penicillium viridicatum at 6 microL. Using agar well diffusion method, leaf volatile oil and oleoresin have shown better results in comparison with bark volatile oil, oleoresin and commercial bactericide, i.e., ampicillin. Gas chromatographic-mass spectroscopy studies on leaf volatile oil and oleoresin resulted in the identification of 19 and 25 components, which accounts for the 99.4% and 97.1%, respectively of the total amount and the major component was eugenol with 87.3% and 87.2%, respectively. The analysis of cinnamon bark volatile oil showed the presence of 13 components accounting for 100% of the total amount. (E)-cinnamaldehyde was found as the major component along with delta-cadinene (0.9%), whereas its bark oleoresin showed the presence of 17 components accounting for 92.3% of the total amount. The major components were (E)-cinnamaldehyde (49.9%), along with several other components.

Alcoholism in cockchafers: orientation of male Melolontha melolontha towards green leaf alcohols

NASA Astrophysics Data System (ADS)

Reinecke, Andreas; Ruther, Joachim; Tolasch, Till; Francke, Wittko; Hilker, Monika

2002-03-01

Chemical orientation of the European cockchafer, Melolontha melolontha L., a serious pest in agriculture and horticulture, was investigated by field tests and electrophysiological experiments using plant volatiles. In total, 16 typical plant volatiles were shown to elicit electrophysiological responses in male cockchafers. Funnel trap field bioassays revealed that green leaf alcohols (i.e. (Z)-3-hexen-1-ol, (E)-2-hexen-1-ol and 1-hexanol) attracted males, whereas the corresponding aldehydes and acetates were behaviourally inactive. Furthermore, male cockchafers were attracted by volatiles from mechanically damaged leaves of Fagus sylvatica L., Quercus robur L. and Carpinus betulus L. However, volatiles emitted by damaged leaves of F. sylvatica attracted significantly more males than those from the other host plants. Odour from intact F. sylvatica leaves was not attractive to M. melolontha males. Females were not attracted by any of the tested volatile sources. The results suggest that plant volatiles play a similar role as a sexual kairomone in mate finding of M. melolontha, as has been shown for the forest cockchafer, Melolontha hippocastani F. Nevertheless, both species show remarkable differences in their reaction to green leaf alcohols.

Retention of nutrients in green leafy vegetables on dehydration.

PubMed

Gupta, Sheetal; Gowri, B S; Lakshmi, A Jyothi; Prakash, Jamuna

2013-10-01

The objective of the study was to investigate the influence of dehydration on nutrient composition of Amaranthus gangeticus, Chenopodium album, Centella asiatica, Amaranthus tricolor and Trigonella foenum graecum. The green leafy vegetables (GLV) were steam blanched for 5 min after pretreatment and dried in an oven at 60 °C for 10-12 h. The fresh and dehydrated samples were analyzed for selected proximate constituents, vitamins, minerals, antinutrients and dialyzable minerals. Dehydration seems to have little effect on the proximate, mineral and antinutrient content of the GLV. Among the vitamins, retention of ascorbic acid was 1-14%, thiamine 22-71%, total carotene 49-73% and β-carotene 20-69% respectively, of their initial content. Dialyzable iron and calcium in the fresh vegetables ranged between 0.21-3.5 mg and 15.36-81.33 mg/100 g respectively, which reduced to 0.05-0.53 mg and 6.94-58.15 mg/100 g on dehydration. Dehydration seems to be the simplest convenient technology for preserving these sources of micronutrients, especially when they are abundantly available. Irrespective of the losses of vitamins that take place during dehydration, dehydrated GLV are a concentrated natural source of micronutrients and they can be used in product formulations. Value addition of traditional products with dehydrated GLV can be advocated as a feasible food-based approach to combat micronutrient malnutrition.

The effect of carbon supply on allocation to allelochemicals and caterpillar consumption of peppermint.

PubMed

Lincoln, D E; Couvet, D

1989-01-01

The carbon supply of peppermint plants was manipulated by growing clonal propagules under three carbon dioxide regimes (350, 500 and 650 μl l -1 ). Feeding by fourth instar caterpillars of Spodoptera eridania increased with elevated CO 2 hostplant regime, as well as with low leaf nitrogen content and by a high proportion of leaf volatile terpenoids. Leaf weight increased significantly with the increased carbon supply, but the amount of nitrogen per leaf did not change. The amount of volatile leaf mono-and sesquiterpenes increased proportionately with total leaf dry weight and hence was not influenced by CO 2 supply. These results are consistent with ecological hypotheses which assume that allocation to defense is closely regulated and not sensitive to carbon supply per se.

Stable power laws in variable economies; Lotka-Volterra implies Pareto-Zipf

NASA Astrophysics Data System (ADS)

Solomon, S.; Richmond, P.

2002-05-01

In recent years we have found that logistic systems of the Generalized Lotka-Volterra type (GLV) describing statistical systems of auto-catalytic elements posses power law distributions of the Pareto-Zipf type. In particular, when applied to economic systems, GLV leads to power laws in the relative individual wealth distribution and in market returns. These power laws and their exponent α are invariant to arbitrary variations in the total wealth of the system and to other endogenously and exogenously induced variations.

Electrophysiological response and attraction of emerald ash borer to green leaf volatiles (GLVs) emitted by host foliage

Treesearch

Peter de Groot; Gary G. Grant; Therese M. Poland; Roger Scharbach; Linda Buchan; Reginald W. Nott; Linda Macdonald; Doug Pitt

2008-01-01

Green leaf volatiles (GLVs) function as host attractants, pheromone synergists, or sexual kairomones for a number of coleopteran folivores. Hence, we focused on host GLVs to determine if they were attractive to adults of the emerald ash borer, Agrilus planipennis (Coleoptera: Buprestidae), which feeds on ash (Fraxinus) foliage....

Silk-elastin-like protein polymer matrix for intraoperative delivery of an oncolytic vaccinia virus.

PubMed

Price, Daniel L; Li, Pingdong; Chen, Chun-Hao; Wong, Danni; Yu, Zhenkun; Chen, Nanhai G; Yu, Yong A; Szalay, Aladar A; Cappello, Joseph; Fong, Yuman; Wong, Richard J

2016-02-01

Oncolytic viral efficacy may be limited by the penetration of the virus into tumors. This may be enhanced by intraoperative application of virus immediately after surgical resection. Oncolytic vaccinia virus GLV-1h68 was delivered in silk-elastin-like protein polymer (SELP) in vitro and in vivo in anaplastic thyroid carcinoma cell line 8505c in nude mice. GLV-1h68 in SELP infected and lysed anaplastic thyroid cancer cells in vitro equally as effectively as in phosphate-buffered saline (PBS), and at 1 week retains a thousand fold greater infectious plaque-forming units. In surgical resection models of residual tumor, GLV-1h68 in SELP improves tumor control and shows increased viral β-galactosidase expression as compared to PBS. The use of SELP matrix for intraoperative oncolytic viral delivery protects infectious viral particles from degradation, facilitates sustained viral delivery and transgene expression, and improves tumor control. Such optimization of methods of oncolytic viral delivery may enhance therapeutic outcomes. © 2014 Wiley Periodicals, Inc.

Silk-elastin-like protein polymer matrix for intraoperative delivery of an oncolytic vaccinia virus

PubMed Central

Price, Daniel L.; Li, Pingdong; Chen, Chun-Hao; Wong, Danni; Yu, Zhenkun; Chen, Nanhai G.; Yu, Yong A.; Szalay, Aladar A.; Cappello, Joseph; Fong, Yuman; Wong, Richard J.

2016-01-01

Background Oncolytic viral efficacy may be limited by the penetration of the virus into tumors. This may be enhanced by intraoperative application of virus immediately after surgical resection. Methods Oncolytic vaccinia virus GLV-1h68 was delivered in silk-elastin-like protein polymer (SELP) in vitro and in vivo in anaplastic thyroid carcinoma cell line 8505c in nude mice. Results GLV-1h68 in SELP infected and lysed anaplastic thyroid cancer cells in vitro equally as effectively as in phosphate-buffered saline (PBS), and at 1 week retains a thousand fold greater infectious plaque-forming units. In surgical resection models of residual tumor, GLV-1h68 in SELP improves tumor control and shows increased viral β-galactosidase expression as compared to PBS. Conclusion The use of SELP matrix for intraoperative oncolytic viral delivery protects infectious viral particles from degradation, facilitates sustained viral delivery and transgene expression, and improves tumor control. Such optimization of methods of oncolytic viral delivery may enhance therapeutic outcomes. PMID:25244076

Of microbes and men: Determining sources of nitrate in a high alpine catchment in the Front Range of Colorado and science outreach on alpine hydrology

NASA Astrophysics Data System (ADS)

Hafich, Katya A.

High elevation ecosystems throughout the Colorado Front Range are undergoing changes in biogeochemical cycling due to an increase in nitrogen deposition in precipitation and a changing climate. While nitrate concentrations continue to rise in surface water of the Green Lakes Valley (GLV) by 0.27 umol L-1 per year, atmospheric deposition of inorganic nitrogen has recently curtailed due to drought, leaving a gap in our understanding of the source of the increased export of nitrate. Here, we employ a novel triple isotope method, using Delta 17O-NO3- for the first time in an alpine catchment to quantify the terrestrial and atmospheric contribution of nitrate to numerous water types in GLV. Results show that nitrate in surface waters, including talus, soil water and rock glacier melt, is more than 75% terrestrial, with the strongest atmospheric signals present during snowmelt. Results suggest that alpine catchment biogeochemistry in GLV has transitioned to a net nitrification system.

Sea-ice floe-size distribution in the context of spontaneous scaling emergence in stochastic systems.

PubMed

Herman, Agnieszka

2010-06-01

Sea-ice floe-size distribution (FSD) in ice-pack covered seas influences many aspects of ocean-atmosphere interactions. However, data concerning FSD in the polar oceans are still sparse and processes shaping the observed FSD properties are poorly understood. Typically, power-law FSDs are assumed although no feasible explanation has been provided neither for this one nor for other properties of the observed distributions. Consequently, no model exists capable of predicting FSD parameters in any particular situation. Here I show that the observed FSDs can be well represented by a truncated Pareto distribution P(x)=x(-1-α) exp[(1-α)/x] , which is an emergent property of a certain group of multiplicative stochastic systems, described by the generalized Lotka-Volterra (GLV) equation. Building upon this recognition, a possibility of developing a simple agent-based GLV-type sea-ice model is considered. Contrary to simple power-law FSDs, GLV gives consistent estimates of the total floe perimeter, as well as floe-area distribution in agreement with observations.

Sea-ice floe-size distribution in the context of spontaneous scaling emergence in stochastic systems

NASA Astrophysics Data System (ADS)

Herman, Agnieszka

2010-06-01

Sea-ice floe-size distribution (FSD) in ice-pack covered seas influences many aspects of ocean-atmosphere interactions. However, data concerning FSD in the polar oceans are still sparse and processes shaping the observed FSD properties are poorly understood. Typically, power-law FSDs are assumed although no feasible explanation has been provided neither for this one nor for other properties of the observed distributions. Consequently, no model exists capable of predicting FSD parameters in any particular situation. Here I show that the observed FSDs can be well represented by a truncated Pareto distribution P(x)=x-1-αexp[(1-α)/x] , which is an emergent property of a certain group of multiplicative stochastic systems, described by the generalized Lotka-Volterra (GLV) equation. Building upon this recognition, a possibility of developing a simple agent-based GLV-type sea-ice model is considered. Contrary to simple power-law FSDs, GLV gives consistent estimates of the total floe perimeter, as well as floe-area distribution in agreement with observations.

The overexpression and nuclear translocation of Trx-1 during hypoxia confers on HepG2 cells resistance to DDP, and GL-V9 reverses the resistance by suppressing the Trx-1/Ref-1 axis.

PubMed

Zhao, Li; Li, Wei; Zhou, Yuxin; Zhang, Yi; Huang, Shaoliang; Xu, Xuefen; Li, Zhiyu; Guo, Qinglong

2015-05-01

Microenvironmental hypoxia gives many tumor cells the capacity for drug resistance. Thioredoxin family members play critical roles in the regulation of cellular redox homeostasis in a stressed environment. In this study, we established a hypoxia-drug resistance (hypoxia-DR) model using HepG2 cells and discovered that the overexpression and nuclear translocation of thioredoxin-1 (Trx-1) are closely associated with this resistance through the regulation of the metabolism by the oxidative stress response to glycolysis. Intranuclear Trx-1 enhances the DNA-binding activity of HIF-1α via its interaction with and reducing action on Ref-1, resulting in increased expression of glycolysis-related proteins (PDHK1, HKII, and LDHA), glucose uptake, and lactate generation under hypoxia. Meanwhile, we found that GL-V9, a newly synthesized flavonoid derivative, shows an ability to reverse the hypoxia-DR and has low toxicity both in vivo and in vitro. GL-V9 could inhibit the expression and nuclear translocation of Trx-1 and then suppress HIF-1α DNA-binding activity by inhibiting the Trx-1/Ref-1 axis. As a result, glycolysis is weakened and oxidative phosphorylation is enhanced. Thus, GL-V9 leads to an increment in intracellular ROS generation and consequently intensified apoptosis induced by DDP. Copyright © 2015 Elsevier Inc. All rights reserved.

Characterization of polar organosulfates in secondary organic aerosol from the green leaf volatile 3-Z-hexenal

EPA Science Inventory

Evidence is provided that the green leaf volatile 3-Z-hexenal serves as a precursor for biogenic secondary organic aerosol through formation of polar organosulfates (OSs) with molecular weights (MW) 226 and 214. The MW 226 C₆-OSs and MW 214 C_5M-OSs were che...

Disproportionate photosynthetic decline and inverse relationship between constitutive and induced volatile emissions upon feeding of Quercus robur leaves by large larvae of gypsy moth (Lymantria dispar)

PubMed Central

Copolovici, Lucian; Pag, Andreea; Kännaste, Astrid; Bodescu, Adina; Tomescu, Daniel; Copolovici, Dana; Soran, Maria-Loredana; Niinemets, Ülo

2018-01-01

Gypsy moth (Lymantria dispar L., Lymantriinae) is a major pest of pedunculate oak (Quercus robur) forests in Europe, but how its infections scale with foliage physiological characteristics, in particular with photosynthesis rates and emissions of volatile organic compounds has not been studied. Differently from the majority of insect herbivores, large larvae of L. dispar rapidly consume leaf area, and can also bite through tough tissues, including secondary and primary leaf veins. Given the rapid and devastating feeding responses, we hypothesized that infection of Q. robur leaves by L. dispar leads to disproportionate scaling of leaf photosynthesis and constitutive isoprene emissions with damaged leaf area, and to less prominent enhancements of induced volatile release. Leaves with 0% (control) to 50% of leaf area removed by larvae were studied. Across this range of infection severity, all physiological characteristics were quantitatively correlated with the degree of damage, but all these traits changed disproportionately with the degree of damage. The net assimilation rate was reduced by almost 10-fold and constitutive isoprene emissions by more than 7-fold, whereas the emissions of green leaf volatiles, monoterpenes, methyl salicylate and the homoterpene (3E)-4,8-dimethy-1,3,7-nonatriene scaled negatively and almost linearly with net assimilation rate through damage treatments. This study demonstrates that feeding by large insect herbivores disproportionately alters photosynthetic rate and constitutive isoprene emissions. Furthermore, the leaves have a surprisingly large capacity for enhancement of induced emissions even when foliage photosynthetic function is severely impaired. PMID:29367792

Semi-volatile organic compounds at the leaf/atmosphere interface: numerical simulation of dispersal and foliar uptake.

PubMed

Riederer, Markus; Daiss, Andreas; Gilbert, Norbert; Köhle, Harald

2002-08-01

The behaviour of (semi-)volatile organic compounds at the interface between the leaf surface and the atmosphere was investigated by finite-element numerical simulation. Three model systems with increasing complexity and closeness to the real situation were studied. The three-dimensional model systems were translated into appropriate grid structures and diffusive and convective transport in the leaf/atmosphere interface was simulated. Fenpropimorph (cis-4-[3-(4-tert-butylphenyl)-2-methylpropyl]-2,6-dimethylmorpholine) and Kresoxim-methyl ((E)-methyl-2-methoxyimino-2-[2-(o-tolyloxy-methyl)phenyl] acetate) were used as model compounds. The simulation showed that under still and convective conditions the vapours emitted by a point source rapidly form stationary envelopes around the leaves. Vapour concentrations within these unstirred layers depend on the vapour pressure of the compound in question and on its affinity to the lipoid surface layers of the leaf (cuticular waxes, cutin). The rules deduced from the numerical simulation of organic vapour behaviour in the leaf/atmosphere interface are expected to help in assessing how (semi-)volatile plant products (e.g. hormones, pheromones, secondary metabolites) and xenobiotics (e.g. pesticides, pollutants) perform on plant surfaces.

The Pathways from a Behavior Change Communication Intervention to Infant and Young Child Feeding in Bangladesh Are Mediated and Potentiated by Maternal Self-Efficacy.

PubMed

Zongrone, Amanda A; Menon, Purnima; Pelto, Gretel H; Habicht, Jean-Pierre; Rasmussen, Kathleen M; Constas, Mark A; Vermeylen, Francoise; Khaled, Adiba; Saha, Kuntal K; Stoltzfus, Rebecca J

2018-02-01

Although self-efficacy is a potential determinant of feeding and care behaviors, there is limited empirical analysis of the role of maternal self-efficacy in low- and middle-income countries. In the context of behavior change interventions (BCIs) addressing complementary feeding (CF), it is possible that maternal self-efficacy can mediate or enhance intervention impacts. In the context of a BCI in Bangladesh, we studied the role of maternal self-efficacy for CF (MSE-CF) for 2 CF behaviors with the use of a theoretically grounded empirical model of determinants to illustrate the potential roles of MSE-CF. We developed and tested a locally relevant scale for MSE-CF and included it in a survey (n = 457 mothers of children aged 6-24 mo) conducted as part of a cluster-randomized evaluation. Qualitative research was used to inform the selection of 2 intervention-targeted behaviors: feeding green leafy vegetables in the last 24 h (GLV) and on-time introduction of egg (EGG) between 6 and 8 mo of age. We then examined direct, mediated, and potentiated paths of MSE-CF in relation to the impacts of the BCI on these behaviors with the use of regression and structural equation modeling. GLV and EGG were higher in the intensive group than in the nonintensive control group (16.0 percentage points for GLV; P < 0.001; 11.2 percentage points for EGG; P = 0.037). For GLV, MSE-CF mediated (β = 0.345, P = 0.010) and potentiated (β = 0.390, P = 0.038) the effect of the intensive group. In contrast, MSE-CF did not mediate or potentiate the effect of the intervention on EGG. MSE-CF was a significant mediator and potentiator for GLV but not for EGG. The divergent findings highlight the complex determinants of individual specific infant and young child feeding behaviors. The study shows the value of measuring behavioral determinants, such as MSE-CF, that affect a caregiver's capability to adopt intervention-targeted behaviors.

Implementation of the effects of physicochemical properties on the foliar penetration of pesticides and its potential for estimating pesticide volatilization from plants.

PubMed

Lichiheb, Nebila; Personne, Erwan; Bedos, Carole; Van den Berg, Frederik; Barriuso, Enrique

2016-04-15

Volatilization from plant foliage is known to have a great contribution to pesticide emission to the atmosphere. However, its estimation is still difficult because of our poor understanding of processes occurring at the leaf surface. A compartmental approach for dissipation processes of pesticides applied on the leaf surface was developed on the base of experimental study performed under controlled conditions using laboratory volatilization chamber. This approach was combined with physicochemical properties of pesticides and was implemented in SURFATM-Pesticides model in order to predict pesticide volatilization from plants in a more mechanistic way. The new version of SURFATM-Pesticide model takes into account the effect of formulation on volatilization and leaf penetration. The model was evaluated in terms of 3 pesticides applied on plants at the field scale (chlorothalonil, fenpropidin and parathion) which display a wide range of volatilization rates. The comparison of modeled volatilization fluxes with measured ones shows an overall good agreement for the three tested compounds. Furthermore the model confirms the considerable effect of the formulation on the rate of the decline in volatilization fluxes especially for systemic products. However, due to the lack of published information on the substances in the formulations, factors accounting for the effect of formulation are described empirically. A sensitivity analysis shows that in addition to vapor pressure, the octanol-water partition coefficient represents important physicochemical properties of pesticides affecting pesticide volatilization from plants. Finally the new version of SURFATM-Pesticides is a prospecting tool for key processes involved in the description of pesticide volatilization from plants. Copyright © 2016 Elsevier B.V. All rights reserved.

Does oolong tea (Camellia sinensis) made from a combination of leaf and stem smell more aromatic than leaf-only tea? Contribution of the stem to oolong tea aroma.

PubMed

Zeng, Lanting; Zhou, Ying; Fu, Xiumin; Mei, Xin; Cheng, Sihua; Gui, Jiadong; Dong, Fang; Tang, Jinchi; Ma, Shengzhou; Yang, Ziyin

2017-12-15

The raw materials used to make oolong tea (Camellia sinensis) are a combination of leaf and stem. Oolong tea made from leaf and stem is thought to have a more aromatic smell than leaf-only tea. However, there is no available evidence to support the viewpoint. In this study, sensory evaluation and detailed characterization of emitted and internal volatiles (not readily emitted, but stored in samples) of dry oolong teas and infusions indicated that the presence of stem did not significantly improve the total aroma characteristics. During the enzyme-active processes, volatile monoterpenes and theanine were accumulated more abundantly in stem than in leaf, while jasmine lactone, indole, and trans-nerolidol were lower in stem than in leaf. Tissue-specific aroma-related gene expression and availability of precursors of aroma compounds resulted in different aroma distributions in leaf and stem. This study presents the first determination of the contribution of stem to oolong tea aroma. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bioaccessibility of selenium, selenomethionine and selenocysteine from foods and influence of heat processing on the same.

PubMed

Khanam, Anjum; Platel, Kalpana

2016-03-01

Selenium (Se) is an essential nutrient with diverse physiological functions. The selenium content of commonly consumed cereals, pulses and green leafy vegetables (GLV) was determined. Bioaccessibility of Se, and its organic forms selenomethionine (SeMet), and selenocysteine (SeCys2) was also examined, and the effect of heat processing on the same was studied. The bioaccessibility of Se in cereals ranged from 10% to 24%, that of pulses was between 12% and 29%, and of GLV, 10-31%. The concentration of SeMet in the dialysates of the cereals, pulses and GLV ranged from 5.15 to 28.7, 2.7 to 36.2, and 0.03 to 5ngg(-1), respectively. The concentration of SeCys2 in the dialysates of the foods examined was negligible. Heat processing significantly decreased the bioaccessibility of Se, SeMet and SeCys2. This is the first report on the bioaccessibility of Se and its major organic forms from commonly consumed staples, and the effect of heat processing on the same. Copyright © 2015 Elsevier Ltd. All rights reserved.

Extraction of Volatile Flavor Compounds From Tobacco Leaf Through a Low-Density Polyethylene Membrane.

PubMed

Yokoi, Michinori; Shimoda, Mitsuya

2017-03-01

A low-density polyethylene (LDPE) membrane pouch method was developed to extract volatile flavor compounds from tobacco leaf. Tobacco leaf suspended in water was enclosed in a pouch prepared from a LDPE membrane of specific gravity 0.92 g/cm3 and 0.03 mm thickness and then extracted with diethyl ether. In comparison with direct solvent extraction, LDPE membrane excluded larger and higher boiling point compounds which could contaminate a gas chromatograph inlet and damage a column. Whilst being more convenient than a reduced-pressure steam distillation, it could extract volatile flavor compounds of wide range of molecular weight and polarity. Repeatabilities in the extracted amounts were ranged from 0.38% of 2.3-bipyridyl to 26% of β-ionone, and average value of 39 compounds was 5.9%. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Identification of leaf volatiles from olive (Olea europaea) and their possible role in the ovipositional preferences of olive fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae).

PubMed

Malheiro, Ricardo; Casal, Susana; Cunha, Sara C; Baptista, Paula; Pereira, José Alberto

2016-01-01

The olive fly, Bactrocera oleae (Rossi), is a monophagous pest that displays an oviposition preference among cultivars of olive (Olea europaea L.). To clarify the oviposition preference, the olive leaf volatiles of three olive cultivars (Cobrançosa, Madural and Verdeal Transmontana) were assessed by headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC/MS) at six different periods of olive fruit maturation and degrees of infestation. A total of 39 volatiles were identified, mainly esters and alcohols, with a minor percentage of aldehydes, ketones and terpenic compounds, including sesquiterpenes. At sampling dates with higher degrees of infestation, cv. Cobrançosa had, simultaneously, significantly lower infestation degrees and higher volatile amounts than the other two cultivars, with a probable deterrent effect for oviposition. The green leaf volatiles (GLVs) (Z)-3-hexen-1-ol and (Z)-3-hexen-1-ol acetate) were the main compounds identified in all cultivars, together with toluene. The abundance of GLVs decreased significantly throughout maturation, without significant differences among cultivars, while toluene showed a general increase and positive correlation with olive fly infestation levels. The results obtained could broaden our understanding of the roles of various types and amounts of olive volatiles in the environment, especially in olive fly host selection and cultivar preference. Copyright © 2015 Elsevier Ltd. All rights reserved.

Phytoseiulus persimilis response to herbivore-induced plant volatiles as a function of mite-days.

PubMed

Nachappa, Punya; Margolies, David C; Nechols, James R; Loughin, Thomas

2006-01-01

The predatory mite, Phytoseiulus persimilis (Acari: Phytoseiidae), uses plant volatiles (i.e., airborne chemicals) triggered by feeding of their herbivorous prey, Tetranychus urticae (Acari: Tetranychidae), to help locate prey patches. The olfactory response of P. persimilis to prey-infested plants varies in direct relation to the population growth pattern of T. urticae on the plant; P. persimilis responds to plants until the spider mite population feeding on a plant collapses, after which infested plants do not attract predators. It has been suggested that this represents an early enemy-free period for T. urticae before the next generation of females is produced. We hypothesize that the mechanism behind the diminished response of predators is due to extensive leaf damage caused by T. urticae feeding, which reduces the production of volatiles irrespective of the collapse of T. urticae population on the plant. To test this hypothesis we investigated how the response of P. persimilis to prey-infested plants is affected by: 1) initial density of T. urticae, 2) duration of infestation, and 3) corresponding leaf damage due to T. urticae feeding. Specifically, we assessed the response of P. persimilis to plants infested with two T. urticae densities (20 or 40 per plant) after 2, 4, 6, 8, 10, 12 or 14 days. We also measured leaf damage on these plants. We found that predator response to T. urticae-infested plants can be quantified as a function of mite-days, which is a cumulative measure of the standing adult female mite population sampled and summed over time. That is, response to volatiles increased with increasing numbers of T. urticae per plant or with the length of time plant was infested by T. urticae, at least as long at the leaves were green. Predatory mites were significantly attracted to plants that were infested for 2 days with only 20 spider mites. This suggests that the enemy-free period might only provide a limited window of opportunity for T. urticae because relatively low numbers of T. urticae per plant can attract predators. Leaf damage also increased as a function of mite-days until the entire leaf was blanched. T. urticae populations decreased at this time, but predator response to volatiles dropped before the entire leaf was blanched and before the T. urticae population decreased. This result supports our hypothesis that predator response to plant volatiles is linked to and limited by the degree of leaf damage, and that the quantitative response to T. urticae populations occurs only within a range when plant quality has not been severely compromised.

Large Drought-induced Variations in Oak Leaf Volatile Organic Compound Emissions during PINOT NOIR 2012

EPA Pesticide Factsheets

Leaf level oak isoprene emissions and co2/H2O exchange in the Ozarks, USABAGeron.csv is the speciated biomass displayed in Figure 1.Biomass Dry Weights.xlsx is used to convert leaf area to dry leaf biomass and is used in Figure 2.Daly Ozarks leaf ISOP.txt and MOFLUX_Isoprene Summary_refined Tcurve data.xlsx are the leaf isoprene emission rate files shown in Figure 2.Harley Aug12_Chris.xls is the leaf isoprene emission rate file shown in Figure 3.Daly Ozarks leaf.txt is the BVOC emissions file used for Figure 7 and Table 4.Drought IS.txt is the review data given in Table 2.Fig4 Aug10 2012 Harley.txt is shown in Figure 4.Fig 5 Aug14 2012 Harley.txt is shown in Figure 5.Daly Ozarks Leaf.txt is used in Fig 7.Drought IS.txt is used in Fig 8.This dataset is associated with the following publication:Geron , C., R. Daly , P. Harley, R. Rasmussen, R. Seco, A. Guenther, T. Karl, and L. Gu. Large Drought-Induced Variations in Oak Leaf Volatile Organic Compound Emissions during PINOT NOIR 2012. CHEMOSPHERE. Elsevier Science Ltd, New York, NY, USA, 146: 8-21, (2016).

Relationships between stream nitrate concentration and spatially distributed snowmelt in high-elevation catchments of the western U.S.

NASA Astrophysics Data System (ADS)

Perrot, Danielle; Molotch, Noah P.; Williams, Mark W.; Jepsen, Steven M.; Sickman, James O.

2014-11-01

This study compares stream nitrate (NO3-) concentrations to spatially distributed snowmelt in two alpine catchments, the Green Lakes Valley, Colorado (GLV4) and Tokopah Basin, California (TOK). A snow water equivalent reconstruction model and Landsat 5 and 7 snow cover data were used to estimate daily snowmelt at 30 m spatial resolution in order to derive indices of new snowmelt areas (NSAs). Estimates of NSA were then used to explain the NO3- flushing behavior for each basin over a 12 year period (1996-2007). To identify the optimal method for defining NSAs and elucidate mechanisms underlying catchment NO3- flushing, we conducted a series of regression analyses using multiple thresholds of snowmelt based on temporal and volumetric metrics. NSA indices defined by volume of snowmelt (e.g., snowmelt ≤ 30 cm) rather than snowmelt duration (e.g., snowmelt ≤ 9 days) were the best predictors of stream NO3- concentrations. The NSA indices were better correlated with stream NO3- concentration in TOK (average R2= 0.68) versus GLV4 (average R2= 0.44). Positive relationships between NSA and stream NO3- concentration were observed in TOK with peak stream NO3- concentration occurring on the rising limb of snowmelt. Positive and negative relationships between NSA and stream NO3- concentration were found in GLV4 with peak stream NO3- concentration occurring as NSA expands. Consistent with previous works, the contrasting NO3- flushing behavior suggests that streamflow in TOK was primarily influenced by overland flow and shallow subsurface flow, whereas GLV4 appeared to be more strongly influenced by deeper subsurface flow paths.

Isolated limb perfusion with melphalan, tumour necrosis factor-alpha and oncolytic vaccinia virus improves tumour targeting and prolongs survival in a rat model of advanced extremity sarcoma.

PubMed

Pencavel, Tim D; Wilkinson, Michelle J; Mansfield, David C; Khan, Aadil A; Seth, Rohit; Karapanagiotou, Eleni M; Roulstone, Victoria; Aguilar, Richard J; Chen, Nanhai G; Szalay, Aladar A; Hayes, Andrew J; Harrington, Kevin J

2015-02-15

Isolated limb perfusion (ILP) is a treatment for advanced extremity sarcoma and in-transit melanoma. Advancing this procedure by investigating the addition of novel agents, such as cancer-selective oncolytic viruses, may improve both the therapeutic efficacy of ILP and the tumour-targeted delivery of oncolytic virotherapy. Standard in vitro assays were used to characterise single agent and combinatorial activities of melphalan, tumour necrosis factor-alpha (TNF-α) and Lister strain vaccinia virus (GLV-1h68) against BN175 rat sarcoma cells. An orthotopic model of advanced extremity sarcoma was used to evaluate survival of animals after ILP with combinations of TNF-α, melphalan and GLV-1h68. We investigated the efficiency of viral tumour delivery by ILP compared to intravenous therapy, the locoregional and systemic biodistribution of virus after ILP, and the effect of mode of administration on antibody response. The combination of melphalan and GLV-1h68 was synergistic in vitro. The addition of virus to standard ILP regimens was well tolerated and demonstrated superior tumour targeting compared to intravenous administration. Triple therapy (melphalan/TNF-α/GLV-1h68) resulted in increased tumour growth delay and enhanced survival compared to other treatment regimens. Live virus was recovered in large amounts from perfused regions, but in smaller amounts from systemic organs. The addition of oncolytic vaccinia virus to existing TNF-α/melphalan-based ILP strategies results in survival advantage in an immunocompetent rat model of advanced extremity sarcoma. Virus administered by ILP has superior tumour targeting compared to intravenous delivery. Further evaluation and clinical translation of this approach is warranted. © 2014 UICC.

Individual-tree tests of verbenone flakes, verbenone pouches, and green-leaf volatiles to protect lodgepole pines from mountain pine beetle attack

Treesearch

Sandra Kegley; Ken Gibson; Nancy Gillette; Jeff Webster; Lee Pederson; Silvia. Mori

2010-01-01

We have long known that the bark beetle-produced pheromone, verbenone (trimethyl-bicyclo-heptenone), can limit damage to pines by scolytid bark beetles (Clarke et al. 1999, Skillen et al. 1997, Syracuse Environmental Research Associates, Inc. 2000). It has also been shown that in some cases the addition of ―green leaf volatiles‖ (GLVs) can increase the efficacy of...

Peer pressure and Generalised Lotka Volterra models

NASA Astrophysics Data System (ADS)

Richmond, Peter; Sabatelli, Lorenzo

2004-12-01

We develop a novel approach to peer pressure and Generalised Lotka-Volterra (GLV) models that builds on the development of a simple Langevin equation that characterises stochastic processes. We generalise the approach to stochastic equations that model interacting agents. The agent models recently advocated by Marsilli and Solomon are motivated. Using a simple change of variable, we show that the peer pressure model (similar to the one introduced by Marsilli) and the wealth dynamics model of Solomon may be (almost) mapped one into the other. This may help shed light in the (apparently) different wealth dynamics described by GLV and the Marsili-like peer pressure models.

In silico analysis of antibiotic-induced Clostridium difficile infection: Remediation techniques and biological adaptations

PubMed Central

Carlson, Jean M.

2018-01-01

In this paper we study antibiotic-induced C. difficile infection (CDI), caused by the toxin-producing C. difficile (CD), and implement clinically-inspired simulated treatments in a computational framework that synthesizes a generalized Lotka-Volterra (gLV) model with SIR modeling techniques. The gLV model uses parameters derived from an experimental mouse model, in which the mice are administered antibiotics and subsequently dosed with CD. We numerically identify which of the experimentally measured initial conditions are vulnerable to CD colonization, then formalize the notion of CD susceptibility analytically. We simulate fecal transplantation, a clinically successful treatment for CDI, and discover that both the transplant timing and transplant donor are relevant to the the efficacy of the treatment, a result which has clinical implications. We incorporate two nongeneric yet dangerous attributes of CD into the gLV model, sporulation and antibiotic-resistant mutation, and for each identify relevant SIR techniques that describe the desired attribute. Finally, we rely on the results of our framework to analyze an experimental study of fecal transplants in mice, and are able to explain observed experimental results, validate our simulated results, and suggest model-motivated experiments. PMID:29451873

In silico analysis of antibiotic-induced Clostridium difficile infection: Remediation techniques and biological adaptations.

PubMed

Jones, Eric W; Carlson, Jean M

2018-02-01

In this paper we study antibiotic-induced C. difficile infection (CDI), caused by the toxin-producing C. difficile (CD), and implement clinically-inspired simulated treatments in a computational framework that synthesizes a generalized Lotka-Volterra (gLV) model with SIR modeling techniques. The gLV model uses parameters derived from an experimental mouse model, in which the mice are administered antibiotics and subsequently dosed with CD. We numerically identify which of the experimentally measured initial conditions are vulnerable to CD colonization, then formalize the notion of CD susceptibility analytically. We simulate fecal transplantation, a clinically successful treatment for CDI, and discover that both the transplant timing and transplant donor are relevant to the the efficacy of the treatment, a result which has clinical implications. We incorporate two nongeneric yet dangerous attributes of CD into the gLV model, sporulation and antibiotic-resistant mutation, and for each identify relevant SIR techniques that describe the desired attribute. Finally, we rely on the results of our framework to analyze an experimental study of fecal transplants in mice, and are able to explain observed experimental results, validate our simulated results, and suggest model-motivated experiments.

Composition and antioxidant activities of leaf and root volatile oils of Morinda lucida.

PubMed

Okoh, Sunday O; Asekun, Olayinka T; Familoni, Oluwole B; Afolayan, Anthony J

2011-10-01

Morinda lucida (L.) Benth. (Rubiacae) is used in traditional medicine in many West African countries for the treatment of various human diseases. The leaves and roots of this plant were subjected to hydro-distillation to obtain volatile oils which were analyzed by high resolution GC/MS. Fifty compounds were identified in the leaf volatile oil and the major compounds were alpha-terpinene (17.8%) and beta-bisabolene (16.3%). In the root oil, 18 compounds were identified, the major constituents being 3-fluoro-p-anidine (51.8%) and hexadecanoic acid (12.0%). Antioxidant activities of the oils were examined using the DPPH, ABTS, reducing power and lipid peroxidation assays. All assays were concentration dependent with varying antioxidant potentials. The antioxidant activity of the root volatile oil of M. lucida was similar to that of the standard drugs used.

Gastrophysa polygoni herbivory on Rumex confertus: Single leaf VOC induction and dose dependent herbivore attraction/repellence to individual compounds

USDA-ARS?s Scientific Manuscript database

We report large induction (> 65fold increases) of volatile organic compounds (VOCs) emitted from a single leaf of the invasive weed mossy sorrel, Rumex confertus Willd. (Polygonaceae), by herbivory of the dock leaf beetle, Gastrophysa polygoni L. (Coleoptera: Chrysomelidae). The R. confertus VOC ble...

Degradation products of citrus volatile organic compounds (VOCs) acting as phagostimulants that increase probing behavior of Asian citrus psyllid

USDA-ARS?s Scientific Manuscript database

Volatile phytochemicals play a role in orientation by phytophagous insects. We studied antennal and behavioral responses of the Asian citrus psyllid, Diaphorina citri Kuwayama, vector of the citrus greening disease pathogen. Little or no response to citrus leaf volatiles was detected by electroanten...

Large drought-induced variations in oak leaf volatile organic compound emissions during PINOT NOIR 2012

DOE PAGES

Geron, Chris; Gu, Lianhong; Daly, Ryan; ...

2015-12-17

Here, leaf-level isoprene and monoterpene emissions were collected and analyzed from five of the most abundant oak (Quercus) species in Central Missouri's Ozarks Region in 2012 during PINOT NOIR (Particle Investigations at a Northern Ozarks Tower – NOx, Oxidants, Isoprene Research). June measurements, prior to the onset of severe drought, showed isoprene emission rates and leaf temperature responses similar to those previously reported in the literature and used in Biogenic Volatile Organic Compound (BVOC) emission models. During the peak of the drought in August, isoprene emission rates were substantially reduced, and response to temperature was dramatically altered, especially for themore » species in the red oak subgenus (Erythrobalanus).« less

Inferring microbial interaction networks from metagenomic data using SgLV-EKF algorithm.

PubMed

Alshawaqfeh, Mustafa; Serpedin, Erchin; Younes, Ahmad Bani

2017-03-27

Inferring the microbial interaction networks (MINs) and modeling their dynamics are critical in understanding the mechanisms of the bacterial ecosystem and designing antibiotic and/or probiotic therapies. Recently, several approaches were proposed to infer MINs using the generalized Lotka-Volterra (gLV) model. Main drawbacks of these models include the fact that these models only consider the measurement noise without taking into consideration the uncertainties in the underlying dynamics. Furthermore, inferring the MIN is characterized by the limited number of observations and nonlinearity in the regulatory mechanisms. Therefore, novel estimation techniques are needed to address these challenges. This work proposes SgLV-EKF: a stochastic gLV model that adopts the extended Kalman filter (EKF) algorithm to model the MIN dynamics. In particular, SgLV-EKF employs a stochastic modeling of the MIN by adding a noise term to the dynamical model to compensate for modeling uncertainties. This stochastic modeling is more realistic than the conventional gLV model which assumes that the MIN dynamics are perfectly governed by the gLV equations. After specifying the stochastic model structure, we propose the EKF to estimate the MIN. SgLV-EKF was compared with two similarity-based algorithms, one algorithm from the integral-based family and two regression-based algorithms, in terms of the achieved performance on two synthetic data-sets and two real data-sets. The first data-set models the randomness in measurement data, whereas, the second data-set incorporates uncertainties in the underlying dynamics. The real data-sets are provided by a recent study pertaining to an antibiotic-mediated Clostridium difficile infection. The experimental results demonstrate that SgLV-EKF outperforms the alternative methods in terms of robustness to measurement noise, modeling errors, and tracking the dynamics of the MIN. Performance analysis demonstrates that the proposed SgLV-EKF algorithm represents a powerful and reliable tool to infer MINs and track their dynamics.

Southern pine beetle, Dendroctonus frontalis, antennal and behavioral responses to nonhost leaf and bark volatiles

Treesearch

William Shepherd; Brian Sullivan

2013-01-01

A growing body of evidence suggests that bark beetles detect and avoid release points of volatile compounds associated with nonhost species, and thus such nonhost volatiles may have potential utility in the management of bark beetles. We used a coupled gas chromatograph-electroantennographic detector (GC-EAD) to assay the olfactory sensitivity of the southern pine...

Analysis of volatiles induced by oviposition of elm leaf beetle Xanthogaleruca luteola on Ulmus minor.

PubMed

Wegener, R; Schulz, S; Meiners, T; Hadwich, K; Hilker, M

2001-03-01

Egg deposition of the elm leaf beetle Xanthogaleruca luteola causes the emission of volatiles from its food plant, Ulmus minor. These volatiles are exploited by the egg parasitoid, Oomyzus gallerucae, to locate its host. In contrast to other tritrophic systems, the release of volatiles is not induced by feeding but by egg deposition. Previous investigations showed that the release is systemic and can be triggered by jasmonic acid. Comparison of headspace analysis revealed similarities in the blend of volatiles emitted following egg deposition and feeding. The mixture consists of more than 40 compounds; most of the substances are terpenoids. Leaves next to those carrying eggs emit fewer compounds. When treated with jasmonic acid, leaves emit a blend that consists almost exclusively of terpenoids. Dichloromethane extracts of leaves treated with jasmonic acid were also investigated. After separation of extracts of jasmonate induced elm leaves on silica, we obtained a fraction of terpenoid hydrocarbons that was attractive to the parasitoids. This indicates that jasmonic acid stimulates the production of terpenoid hydrocarbons that convey information of egg deposition to the parasitoid.

Diel rhythms in the volatile emission of apple and grape foliage.

PubMed

Giacomuzzi, Valentino; Cappellin, Luca; Nones, Stefano; Khomenko, Iuliia; Biasioli, Franco; Knight, Alan L; Angeli, Sergio

2017-06-01

This study investigated the diel emission of volatile organic compounds (VOCs) from intact apple (Malus x domestica Borkh., cv. Golden Delicious) and grape (Vitis vinifera L., cv. Pinot Noir) foliage. Volatiles were monitored continuously for 48 h by proton transfer reaction - time of flight - mass spectrometry (PTR-ToF-MS). In addition, volatiles were collected by closed-loop-stripping-analysis (CLSA) and characterized by gas chromatography-mass spectrometry (GC-MS) after 1 h and again 24 and 48 h later. Fourteen and ten volatiles were characterized by GC-MS in apple and grape, respectively. The majority of these were terpenes, followed by green leaf volatiles, and aromatic compounds. The PTR-ToF-MS identified 10 additional compounds and established their diel emission rhythms. The most abundant volatiles displaying a diel rhythm included methanol and dimethyl sulfide in both plants, acetone in grape, and mono-, homo- and sesquiterpenes in apple. The majority of volatiles were released from both plants during the photophase; whereas methanol, CO 2 , methyl-butenol and benzeneacetaldehyde were released at significantly higher levels during the scotophase. Acetaldehyde, ethanol, and some green leaf volatiles showed distinct emission bursts in both plants following the daily light switch-off. These new results obtained with a combined analytical approach broaden our understanding of the rhythms of constitutive volatile release from two important horticultural crops. In particular, diel emission of sulfur and nitrogen-containing volatiles are reported here for the first time in these two crops. Copyright © 2017. Published by Elsevier Ltd.

Induction of direct and indirect plant responses by jasmonic acid, low spider mite densities, or a combination of jasmonic acid treatment and spider mite infestation.

PubMed

Gols, Rieta; Roosjen, Mara; Dijkman, Herman; Dicke, Marcel

2003-12-01

Jasmonic acid (JA) and the octadecanoid pathway are involved in both induced direct and induced indirect plant responses. In this study, the herbivorous mite, Tetranychus urticae, and its predator, Phytoseiulus persimilis, were given a choice between Lima bean plants induced by JA or spider mites and uninduced control plants. Infestation densities resulting in the induction of predator attractants were much lower than thus far assumed, i.e., predatory mites were significantly attracted to plants that were infested for 2 days with only one or four spider mites per plant. Phytoseiulus persimilis showed a density-dependent response to volatiles from plants that were infested with different numbers of spider mites. Similarly, treating plants with increasing concentrations of JA also led to increased attraction of P. persimilis. Moreover, the duration of spider mite infestation was positively correlated with the proportion of predators that were attracted to mite-infested plants. A pretreatment of the plants with JA followed by a spider mite infestation enhanced the attraction of P. persimilis to plant volatiles compared to attraction to volatiles from plants that were only infested with spider mites and did not receive a pretreatment with JA. The herbivore, T. urticae preferred leaf tissue that previously had been infested with conspecifics to uninfested leaf tissue. In the case of choice tests with JA-induced and control leaf tissue, spider mites slightly preferred control leaf tissue. When spider mites were given a choice between leaf discs induced by JA and leaf discs damaged by spider mite feeding, they preferred the latter. The presence of herbivore induced chemicals and/or spider mite products enhanced settlement of the mites, whereas treatment with JA seemed to impede settlement.

Phytochemical screening and chemical variability in volatile oils of aerial parts of Morinda morindoides.

PubMed

Kiazolu, J Boima; Intisar, Azeem; Zhang, Lingyi; Wang, Yun; Zhang, Runsheng; Wu, Zhongping; Zhang, Weibing

2016-10-01

Morinda morindoides is an important Liberian traditional medicine for the treatment of malaria, fever, worms etc. The plant was subjected to integrated approaches including phytochemical screening and gas chromatography mass spectrometry (GC-MS) analyses. Phytochemical investigation of the powdered plant revealed the presence of phenolics, tannins, flavonoids, saponins, terpenes, steroidal compounds and volatile oil. Steam distillation followed by GC-MS resulted in the identification of 47 volatiles in its aerial parts: 28 were in common including various bioactive volatiles. Major constituents of leaves were phytol (43.63%), palmitic acid (8.55%) and geranyl linalool (6.95%) and stem were palmitic acid (14.95%), eicosane (9.67%) and phytol (9.31%), and hence, a significant difference in the percentage composition of aerial parts was observed. To study seasonal changes, similarity analysis was carried out by calculating correlation coefficient (r) and vector angle cosine (z) that were more than 0.91 for stem-to-stem and leaf-to-leaf batches indicating considerable consistency.

Plant leaves as indoor air passive samplers for volatile organic compounds (VOCs).

PubMed

Wetzel, Todd A; Doucette, William J

2015-03-01

Volatile organic compounds (VOCs) enter indoor environments through internal and external sources. Indoor air concentrations of VOCs vary greatly but are generally higher than outdoors. Plants have been promoted as indoor air purifiers for decades, but reports of their effectiveness differ. However, while air-purifying applications may be questionable, the waxy cuticle coating on leaves may provide a simple, cost-effective approach to sampling indoor air for VOCs. To investigate the potential use of plants as indoor air VOC samplers, a static headspace approach was used to examine the relationship between leaf and air concentrations, leaf lipid contents and octanol-air partition coefficients (Koa) for six VOCs and four plant species. The relationship between leaf and air concentrations was further examined in an actual residence after the introduction of several chlorinated VOC emission sources. Leaf-air concentration factors (LACFs), calculated from linear regressions of the laboratory headspace data, were found to increase as the solvent extractable leaf lipid content and Koa value of the VOC increased. In the studies conducted in the residence, leaf concentrations paralleled the changing air concentrations, indicating a relatively rapid air to leaf VOC exchange. Overall, the data from the laboratory and residential studies illustrate the potential for plant leaves to be used as cost effective, real-time indoor air VOC samplers. Copyright © 2014 Elsevier Ltd. All rights reserved.

NATURAL VOLATILE ORGANIC COMPOUND EMISSION RATE ESTIMATES FOR U.S. WOODLAND LANDSCAPES

EPA Science Inventory

Volatile organic compound (VOC) emission rate factors are estimated for 49 tree genera based on a review of foliar emission rate measurements. oliar VOC emissions are grouped into three categories: isoprene, monoterpenes and other VOC'S. ypical emission rates at a leaf temperatur...

Leaf area index, leaf mass density, and allometric relationships derived from harvest of blue oaks in a California oak savanna

Treesearch

John F. Karlik; Alistair H. McKay

2002-01-01

Given the key role played by biogenic volatile organic compounds (BVOC) in tropospheric chemistry and regional air quality, it is critical to generate accurate BVOC emission inventories. Because oak species found in California often have high BVOC emission rates, and are often of large stature with corresponding large leaf masses, oaks may be the most important genus...

Isoprene emission by poplar is not important for the feeding behaviour of poplar leaf beetles.

PubMed

Müller, Anna; Kaling, Moritz; Faubert, Patrick; Gort, Gerrit; Smid, Hans M; Van Loon, Joop J A; Dicke, Marcel; Kanawati, Basem; Schmitt-Kopplin, Philippe; Polle, Andrea; Schnitzler, Jörg-Peter; Rosenkranz, Maaria

2015-06-30

Chrysomela populi (poplar leaf beetle) is a common herbivore in poplar plantations whose infestation causes major economic losses. Because plant volatiles act as infochemicals, we tested whether isoprene, the main volatile organic compound (VOC) produced by poplars (Populus x canescens), affects the performance of C. populi employing isoprene emitting (IE) and transgenic isoprene non-emitting (NE) plants. Our hypothesis was that isoprene is sensed and affects beetle orientation or that the lack of isoprene affects plant VOC profiles and metabolome with consequences for C. populi feeding. Electroantennographic analysis revealed that C. populi can detect higher terpenes, but not isoprene. In accordance to the inability to detect isoprene, C. populi showed no clear preference for IE or NE poplar genotypes in the choice experiments, however, the beetles consumed a little bit less leaf mass and laid fewer eggs on NE poplar trees in field experiments. Slight differences in the profiles of volatile terpenoids between IE and NE genotypes were detected by gas chromatography - mass spectrometry. Non-targeted metabolomics analysis by Fourier Transform Ion Cyclotron Resonance Mass Spectrometer revealed genotype-, time- and herbivore feeding-dependent metabolic changes both in the infested and adjacent undamaged leaves under field conditions. We show for the first time that C. populi is unable to sense isoprene. The detected minor differences in insect feeding in choice experiments and field bioassays may be related to the revealed changes in leaf volatile emission and metabolite composition between the IE and NE poplars. Overall our results indicate that lacking isoprene emission is of minor importance for C. populi herbivory under natural conditions, and that the lack of isoprene is not expected to change the economic losses in poplar plantations caused by C. populi infestation.

Nocturnal herbivore-induced plant volatiles attract the generalist predatory earwig Doru luteipes Scudder

NASA Astrophysics Data System (ADS)

Naranjo-Guevara, Natalia; Peñaflor, Maria Fernanda G. V.; Cabezas-Guerrero, Milton F.; Bento, José Maurício S.

2017-10-01

Numerous studies have demonstrated that entomophagous arthropods use herbivore-induced plant volatile (HIPV) blends to search for their prey or host. However, no study has yet focused on the response of nocturnal predators to volatile blends emitted by prey damaged plants. We investigated the olfactory behavioral responses of the night-active generalist predatory earwig Doru luteipes Scudder (Dermaptera: Forficulidae) to diurnal and nocturnal volatile blends emitted by maize plants ( Zea mays) attacked by either a stem borer ( Diatraea saccharalis) or a leaf-chewing caterpillar ( Spodoptera frugiperda), both suitable lepidopteran prey. Additionally, we examined whether the earwig preferred odors emitted from short- or long-term damaged maize. We first determined the earwig diel foraging rhythm and confirmed that D. luteipes is a nocturnal predator. Olfactometer assays showed that during the day, although the earwigs were walking actively, they did not discriminate the volatiles of undamaged maize plants from those of herbivore damaged maize plants. In contrast, at night, earwigs preferred volatiles emitted by maize plants attacked by D. saccharalis or S. frugiperda over undamaged plants and short- over long-term damaged maize. Our GC-MS analysis revealed that short-term damaged nocturnal plant volatile blends were comprised mainly of fatty acid derivatives (i.e., green leaf volatiles), while the long-term damaged plant volatile blend contained mostly terpenoids. We also observed distinct volatile blend composition emitted by maize damaged by the different caterpillars. Our results showed that D. luteipes innately uses nocturnal herbivore-induced plant volatiles to search for prey. Moreover, the attraction of the earwig to short-term damaged plants is likely mediated by fatty acid derivatives.

Two volatile organic compounds trigger plant self-defense against a bacterial pathogen and a sucking insect in cucumber under open field conditions.

PubMed

Song, Geun Cheol; Ryu, Choong-Min

2013-05-08

Systemic acquired resistance (SAR) is a plant self-defense mechanism against a broad-range of pathogens and insect pests. Among chemical SAR triggers, plant and bacterial volatiles are promising candidates for use in pest management, as these volatiles are highly effective, inexpensive, and can be employed at relatively low concentrations compared with agrochemicals. However, such volatiles have some drawbacks, including the high evaporation rate of these compounds after application in the open field, their negative effects on plant growth, and their inconsistent levels of effectiveness. Here, we demonstrate the effectiveness of volatile organic compound (VOC)-mediated induced resistance against both the bacterial angular leaf spot pathogen, Pseudononas syringae pv. lachrymans, and the sucking insect aphid, Myzus persicae, in the open field. Using the VOCs 3-pentanol and 2-butanone where fruit yields increased gave unexpectedly, a significant increase in the number of ladybird beetles, Coccinella septempunctata, a natural enemy of aphids. The defense-related gene CsLOX was induced by VOC treatment, indicating that triggering the oxylipin pathway in response to the emission of green leaf volatiles can recruit the natural enemy of aphids. These results demonstrate that VOCs may help prevent plant disease and insect damage by eliciting induced resistance, even in open fields.

Large Drought-Induced Variations in Oak Leaf Volatile Organic Compound Emissions during PINOT NOIR 2012

EPA Science Inventory

Leaf-level isoprene and monoterpene emissions were collected and analyzed from five of the most abundant oak (Quercus) species in Central Missouri’s Ozarks Region in 2012 during PINOT NOIR (Particle Investigations at a Northern Ozarks Tower ‐ NOx, Oxidants, Isoprene Research). Ju...

Heteroclinic dynamics of coupled semiconductor lasers with optoelectronic feedback.

PubMed

Shahin, S; Vallini, F; Monifi, F; Rabinovich, M; Fainman, Y

2016-11-15

Generalized Lotka-Volterra (GLV) equations are important equations used in various areas of science to describe competitive dynamics among a population of N interacting nodes in a network topology. In this Letter, we introduce a photonic network consisting of three optoelectronically cross-coupled semiconductor lasers to realize a GLV model. In such a network, the interaction of intensity and carrier inversion rates, as well as phases of laser oscillator nodes, result in various dynamics. We study the influence of asymmetric coupling strength and frequency detuning between semiconductor lasers and show that inhibitory asymmetric coupling is required to achieve consecutive amplitude oscillations of the laser nodes. These studies were motivated primarily by the dynamical models used to model brain cognitive activities and their correspondence with dynamics obtained among coupled laser oscillators.

Drought and leaf herbivory influence floral volatiles and pollinator attraction

Treesearch

Laura A. Burkle; Justin B. Runyon

2016-01-01

The effects of climate change on species interactions are poorly understood. Investigating the mechanisms by which species interactions may shift under altered environmental conditions will help form a more predictive understanding of such shifts. In particular, components of climate change have the potential to strongly influence floral volatile organic...

LEAF, BRANCH, STAND & LANDSCAPE SCALE MEASUREMENTS OF VOLATILE ORGANIC COMPOUND FLUXES FROM U.S. WOODLANDS

EPA Science Inventory

Natural volatile organic compounds (VOC) fluxes were measured in three U.S. woodlands in summer 1993. Fluxes from individual leaves and branches were estimated with enclosure techniques and used to initialize and evaluate VOC emission model estimates. Ambient measurements were us...

Weeding volatiles reduce leaf and seed damage to field-grown soybeans and increase seed isoflavones.

PubMed

Shiojiri, Kaori; Ozawa, Rika; Yamashita, Ken-Ichi; Uefune, Masayoshi; Matsui, Kenji; Tsukamoto, Chigen; Tokumaru, Susumu; Takabayashi, Junji

2017-01-30

Field experiments were conducted over 3 years (2012, 2013, and 2015), in which half of the young stage soybean plants were exposed to volatiles from cut goldenrods three times over 2-3 weeks, while the other half remained unexposed. There was a significant reduction in the level of the total leaf damage on exposed soybean plants compared with unexposed ones. In 2015, the proportion of damage to plants by Spodoptera litura larvae, a dominant herbivore, was significantly less in the exposed field plots than in the unexposed plots. Under laboratory conditions, cut goldenrod volatiles induced the direct defenses of soybean plants against S. litura larvae and at least three major compounds, α-pinene, β-myrcene, and limonene, of cut goldenrod volatiles were involved in the induction. The number of undamaged seeds from the exposed plants was significantly higher than that from unexposed ones. Concentrations of isoflavones in the seeds were significantly higher in seeds from the exposed plants than in those from the unexposed plants. Future research evaluating the utility of weeding volatiles, as a form of plant-plant communications, in pest management programs is necessary.

Chemical composition and antimicrobial activity of the volatile fractions from leaves and flowers of the wild Iraqi Kurdish plant Prangos peucedanifolia FENZL.

PubMed

Brusotti, Gloria; Ibrahim, Mohammed Farhad; Dentamaro, Alessandra; Gilardoni, Gianluca; Tosi, Solveig; Grisoli, Pietro; Dacarro, Cesare; Guglielminetti, Maria Lidia; Hussain, Faiq Hama Saeed; Caccialanza, Gabriele; Vidari, Giovanni

2013-02-01

The volatile fractions isolated from Prangos peucedanifolia FENZL leaves and flowers were investigated for their phytochemical composition and biological properties. Flower and leaf hydrodistillation afforded 3.14 and 0.49 g of yellowish oils in 1.25 and 0.41% yields, respectively, from dry vegetable materials. According to the GC-FID and GC/MS analyses, 36 (99.35% of the total oil composition) and 26 compounds (89.12%) were identified in the two oils, respectively. The major constituents in the flower volatile fraction were β-pinene (35.58%), α-pinene (22.13%), and β-phellandrene (12.54%), while m-cresol (50.38%) was the main constituent of the leaf volatile fraction. The antimicrobial activity was evaluated against several bacterial and fungal strains, on the basis of the minimum inhibitory concentration (MIC) by the micro- and macrodilution methods. The two volatile fractions showed moderate antifungal and antibacterial activities, especially against Trichophyton rubrum (MIC of 2×10(3) μg/ml), Streptococcus mutans, Streptococcus pyogenes, and Staphylococcus aureus (MIC≤1.9×10(3) μg/ml for all). Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

Localization of production and emission of pollinator attractant on whole leaves of Chamaerops humilis (Arecaceae).

PubMed

Caissard, Jean-Claude; Meekijjironenroj, Aroonrat; Baudino, Sylvie; Anstett, Marie-Charlotte

2004-08-01

Volatile compounds, which frequently play important roles in plant-insect interaction, can be produced either by flowers to attract pollinators or by leaves to deter herbivores. The specialized structures associated with odor production differ in these two organs. The European dwarf palm Chamaerops humilis represents a unique intermediate between these two. In previous work, its leaves were shown to produce volatile organic compounds (VOCs) that attract pollinators only during flowering. Because the leaf sinuses look like a gland, the sinus was examined histologically and with environmental scanning electron microscopy (ESEM) for evidence that the sinus emits VOCs. Volatile compounds emitted by the different parts of the leaf were extracted by washes and headspace then analyzed by gas chromatograph-mass spectrometer (GC-MS). The sinus does not have the expected gland-like structure; the VOCs are actually produced by the whole leaf, even if the composition of the VOCs emitted by the sinus slightly differs. Thus, attraction of pollinators does not result from specialized secreting cells in leaves of flowering European dwarf palms. The results are discussed in the context of a convergent evolution of leaves toward petals.

The Urban Forest Effects (UFORE) model: quantifying urban forest structure and functions

Treesearch

David J. Nowak; Daniel E. Crane

2000-01-01

The Urban Forest Effects (UFORE) computer model was developed to help managers and researchers quantify urban forest structure and functions. The model quantifies species composition and diversity, diameter distribution, tree density and health, leaf area, leaf biomass, and other structural characteristics; hourly volatile organic compound emissions (emissions that...

Green leaf volatiles, fire and nonanoic acid activate MAPkinases in the model grass species Lolium temulentum

USDA-ARS?s Scientific Manuscript database

Forage and turf related grasses are utilized in diverse environments where they are routinely subjected to herbicides and exposed to fire and volatiles after cutting, however very little is known concerning the perception or molecular responses to these different stresses or compounds. In the model ...

1996-2007 Interannual Spatio-Temporal Variability in Snowmelt in Two Montane Watersheds

NASA Astrophysics Data System (ADS)

Jepsen, S. M.; Molotch, N. P.; Williams, M. W.; Rittger, K. E.; Sickman, J. O.

2010-12-01

Snowmelt is a primary water resource for urban/agricultural centers and ecosystems near mountain regions. Stream chemistry from montane catchments is controlled by the flowpaths of water from snowmelt and the timing and duration of snow coverage. A process level understanding of the variability in these processes requires an understanding of the effect of changing climate and anthropogenic loading on spatio-temporal snowmelt patterns. With this as our objective, we applied a snow reconstruction model (SRM) to two well-studied montane watersheds, Tokopah Basin (TOK), California and Green Lake 4 Valley (GLV), Colorado, to examine interannual variability in the timing and location of snowmelt in response to variable climate conditions during the period from 1996 to 2007. The reconstruction model back solves for snowmelt by combining surface energy fluxes, inferred from meteorological data, with sequences of melt season snow images derived from satellite data (i.e., snowmelt depletion curves). The SRM explained 84% of the observed interannual variability in maximum watershed SWE in TOK, with errors ranging from -23 to +27% for the different years. For GLV4, the SRM explained 61% of the interannual variability, with errors ranging from -37 to +34%. In GLV4, interannual variability in snowmelt timing is a factor of four greater than the variability in streamflow timing, unlike in TOK where the ratio is nearly 1:1. We attribute this difference primarily to differences in the magnitude of the turbulent fluxes and the hydrogeology of the two study areas.

Possible role of plant volatiles in tolerance against huanglongbing in citrus

PubMed Central

Hijaz, Faraj; Nehela, Yasser; Killiny, Nabil

2016-01-01

abstract Volatile organic compounds (VOC) play an important role in protecting plants from insect and pathogen attack. In this study, we investigated the leaf volatile profiles of 14 citrus varieties. The VOC in citrus leaves were extracted with n-hexane and analyzed using gas chromatography-mass spectrometry (GC-MS). Overall, 4six volatile compounds were identified in the n-hexane extract from citrus leaves. Most of the detected compounds belonged to 3 main groups (monoterpenes, sesquiterpenes, and aliphatic aldehydes). Principle component analysis was used to examine the relative distribution of the studied varieties to each other. Interestingly, volatile profiles of varieties that are tolerant to Candidatus Liberibacter asiaticus (CLas) were different from those of the susceptible ones. Tolerant and moderately-tolerant cultivars contained relatively higher amounts of volatiles than susceptible varieties. In addition, tolerant varieties were also higher in specific compounds which are known for their antimicrobial activities. These compounds include Aldehydes (undecanal, neral, geranial, and citronellal) and some monoterpenes such as linalool, d-limonene, myrcene, α- and β- phellandrene. In addition, some sesquiterpene compounds including t-caryophellene, γ-elemene, β-elemene, germacrene D, and geranyl acetate were higher in tolerant and moderately tolerant cultivars. Severinia buxifolia which is known for its tolerance to CLas and many other pathogens contained higher levels of santalenes and coumarins. Our results indicated that citrus leaf volatiles might play a role in citrus tolerance to CLas. The results of this study may help in understanding of the mechanism of citrus tolerance against CLas. PMID:26829496

Possible role of plant volatiles in tolerance against huanglongbing in citrus.

PubMed

Hijaz, Faraj; Nehela, Yasser; Killiny, Nabil

2016-01-01

Volatile organic compounds (VOC) play an important role in protecting plants from insect and pathogen attack. In this study, we investigated the leaf volatile profiles of 14 citrus varieties. The VOC in citrus leaves were extracted with n-hexane and analyzed using gas chromatography-mass spectrometry (GC-MS). Overall, 4six volatile compounds were identified in the n-hexane extract from citrus leaves. Most of the detected compounds belonged to 3 main groups (monoterpenes, sesquiterpenes, and aliphatic aldehydes). Principle component analysis was used to examine the relative distribution of the studied varieties to each other. Interestingly, volatile profiles of varieties that are tolerant to Candidatus Liberibacter asiaticus (CLas) were different from those of the susceptible ones. Tolerant and moderately-tolerant cultivars contained relatively higher amounts of volatiles than susceptible varieties. In addition, tolerant varieties were also higher in specific compounds which are known for their antimicrobial activities. These compounds include Aldehydes (undecanal, neral, geranial, and citronellal) and some monoterpenes such as linalool, d-limonene, myrcene, α- and β- phellandrene. In addition, some sesquiterpene compounds including t-caryophellene, γ-elemene, β-elemene, germacrene D, and geranyl acetate were higher in tolerant and moderately tolerant cultivars. Severinia buxifolia which is known for its tolerance to CLas and many other pathogens contained higher levels of santalenes and coumarins. Our results indicated that citrus leaf volatiles might play a role in citrus tolerance to CLas. The results of this study may help in understanding of the mechanism of citrus tolerance against CLas.

New insights into the parametrization of temperature and light responses of mono - and sesquiterpene emissions from Aleppo pine and rosemary

NASA Astrophysics Data System (ADS)

Staudt, M.; Bourgeois, I.; Al Halabi, R.; Song, W.; Williams, J.

2017-03-01

Phytogenic emission of large volatile organic compounds (VOCs) such as monoterpenes (MTs) and sesquiterpenes (SQTs) are key precursors to the formation and growth of atmospheric particles. However, controlled environment studies to elucidate emission responses to temperature and light are still sparse. In this study, the volatile contents and emission responses of Aleppo pine and Rosemary have been investigated. These two common Mediterranean species store semivolatiles inside (resin ducts) and outside (trichomes) their foliage tissues respectively. Both species emitted mainly MTs with basal emission rates of around 5 (Rosemary) and 10 (pine) μg g-1 h-1 and SQTs about one order of magnitude lower. In Aleppo pine, two volatile sources could be clearly distinguished: 1) de-novo synthesized emission of (E)-β-ocimene and linalool, which accounted for about 70% of the total VOC release, were not found in foliar VOC extracts and expressed light dependency (LD) and temperature responses typical for enzyme driven emissions; and 2) storage-derived emissions of various MTs and SQTs whose emissions increased exponentially with temperature, showed no light dependency and were all present in leaf extracts. In Rosemary, all emitted MTs and SQTs including many oxygenated compounds, showed responses typical for stored volatiles and were all found in leaf extracts. The emissions of individual volatiles or volatile classes could be well described with the commonly applied empirical algorithms developed for LD or non LD emissions. However, the shapes of the temperature responses, and hence the deduced coefficient values, were significantly different between oxygenated and non-oxygenated compounds. They also differed between the storage-derived emissions of the two plant species, for individual VOCs or VOC classes. We address the possible reasons for this variation in temperature responses and argue that they are mostly due to molecular interactions along the species specific leaf-internal diffusion paths including the build-up of transient VOC pools and degradation.

The maize lipoxygenase, ZmLOX10, mediates green leaf volatile, jasmonate, and herbivore-induced plant volatile production for defense against insect attack

USDA-ARS?s Scientific Manuscript database

Fatty acid derivatives are of central importance for plant immunity against insect herbivores. However, major regulatory genes and the signals that modulate these defense metabolites are vastly understudied, especially in important agro-economic monocot species. Here we show that products and sign...

Fresh, dried or smoked? repellent properties of volatiles emitted from ethnomedicinal plant leaves against malaria and yellow fever vectors in Ethiopia

PubMed Central

2011-01-01

Background In the search for plant-based mosquito repellents, volatile emanations were investigated from five plant species, Corymbia citriodora, Ocimum suave, Ocimum lamiifolium, Olea europaea and Ostostegia integrifolia, traditionally used in Ethiopia as protection against mosquitoes. Methods The behaviour of two mosquitoes, the malaria vector Anopheles arabiensis and the arbovirus vector Aedes aegypti, was assessed towards volatiles collected from the headspace of fresh and dried leaves, and the smoke from burning the dried leaves in a two-choice landing bioassay and in the background of human odour. Results Volatile extracts from the smoke of burning dried leaves were found to be more repellent than those from fresh leaves, which in turn were more repellent to mosquitoes than volatiles from dried leaves. Of all smoke and fresh volatile extracts, those from Co. citriodora (52-76%) and Oc. suave (58-68%) were found to be the most repellent, Os. integrifolia (29-56%) to be intermediate while Ol. europaea (23-40%) and Os. integrifolia (19-37%) were the least repellent. One volatile present in each of the fresh leaf extracts of Co. citriodora, Oc. suave and Os. integrifolia was ß-ocimene. The levels of ß-ocimene reflected the mosquito repellent activity of these three fresh leaf extracts. Female host-seeking mosquitoes responded dose-dependently to ß-ocimene, both physiologically and behaviourally, with a maximal behavioural repulsion at 14% ß-ocimene. ß-ocimene (14%) repels mosquitoes in our 6-minute landing assays comparable to the synthetic insect repellent N,N-diethyl-m-toluamide (10% DEET). Conclusions Volatiles in the smoke of burning as well as fresh leaves of Co. citriodora and Oc. suave have significant repellent properties against host seeking An. arabiensis and Ae. aegypti mosquitoes. ß-ocimene, present in the fresh leaf headspace of Co. citriodora, Oc. suave and Os. integrifolia, is a significantly effective volatile mosquito repellent in the laboratory. In addition to its repellent properties, ß-ocimene has long approved safe for use in food and cosmetics, making this volatile an intriguing compound to pursue in further tests in the laboratory and field to validate its mosquito repellent activity and potential for use in a commercial product. Also, the landing bioassay with humanised membranes is a potentially useful repellent screening technique that does not require the exposure of humans to the vectors, however further tests in parallel with conventional techniques are advised. PMID:22182798

Fresh, dried or smoked? Repellent properties of volatiles emitted from ethnomedicinal plant leaves against malaria and yellow fever vectors in Ethiopia.

PubMed

Dube, Fitsum Fikru; Tadesse, Kassahun; Birgersson, Göran; Seyoum, Emiru; Tekie, Habte; Ignell, Rickard; Hill, Sharon R

2011-12-19

In the search for plant-based mosquito repellents, volatile emanations were investigated from five plant species, Corymbia citriodora, Ocimum suave, Ocimum lamiifolium, Olea europaea and Ostostegia integrifolia, traditionally used in Ethiopia as protection against mosquitoes. The behaviour of two mosquitoes, the malaria vector Anopheles arabiensis and the arbovirus vector Aedes aegypti, was assessed towards volatiles collected from the headspace of fresh and dried leaves, and the smoke from burning the dried leaves in a two-choice landing bioassay and in the background of human odour. Volatile extracts from the smoke of burning dried leaves were found to be more repellent than those from fresh leaves, which in turn were more repellent to mosquitoes than volatiles from dried leaves. Of all smoke and fresh volatile extracts, those from Co. citriodora (52-76%) and Oc. suave (58-68%) were found to be the most repellent, Os. integrifolia (29-56%) to be intermediate while Ol. europaea (23-40%) and Os. integrifolia (19-37%) were the least repellent. One volatile present in each of the fresh leaf extracts of Co. citriodora, Oc. suave and Os. integrifolia was ß-ocimene. The levels of ß-ocimene reflected the mosquito repellent activity of these three fresh leaf extracts. Female host-seeking mosquitoes responded dose-dependently to ß-ocimene, both physiologically and behaviourally, with a maximal behavioural repulsion at 14% ß-ocimene. ß-ocimene (14%) repels mosquitoes in our 6-minute landing assays comparable to the synthetic insect repellent N,N-diethyl-m-toluamide (10% DEET). Volatiles in the smoke of burning as well as fresh leaves of Co. citriodora and Oc. suave have significant repellent properties against host seeking An. arabiensis and Ae. aegypti mosquitoes. ß-ocimene, present in the fresh leaf headspace of Co. citriodora, Oc. suave and Os. integrifolia, is a significantly effective volatile mosquito repellent in the laboratory. In addition to its repellent properties, ß-ocimene has long approved safe for use in food and cosmetics, making this volatile an intriguing compound to pursue in further tests in the laboratory and field to validate its mosquito repellent activity and potential for use in a commercial product. Also, the landing bioassay with humanised membranes is a potentially useful repellent screening technique that does not require the exposure of humans to the vectors, however further tests in parallel with conventional techniques are advised.

Evaluation of Methane from Sisal Leaf Residue and Palash Leaf Litter

NASA Astrophysics Data System (ADS)

Arisutha, S.; Baredar, P.; Deshpande, D. M.; Suresh, S.

2014-12-01

The aim of this study is to evaluate methane production from sisal leaf residue and palash leaf litter mixed with different bulky materials such as vegetable market waste, hostel kitchen waste and digested biogas slurry in a laboratory scale anaerobic reactor. The mixture was prepared with 1:1 proportion. Maximum methane content of 320 ml/day was observed in the case of sisal leaf residue mixed with vegetable market waste as the feed. Methane content was minimum (47 ml/day), when palash leaf litter was used as feed. This was due to the increased content of lignin and polyphenol in the feedstock which were of complex structure and did not get degraded directly by microorganisms. Sisal leaf residue mixtures also showed highest content of volatile fatty acids (VFAs) as compared to palash leaf litter mixtures. It was observed that VFA concentration in the digester first increased, reached maximum (when pH was minimum) and then decreased.

A system and methodology for measuring volatile organic compounds produced by hydroponic lettuce in a controlled environment

NASA Technical Reports Server (NTRS)

Charron, C. S.; Cantliffe, D. J.; Wheeler, R. M.; Manukian, A.; Heath, R. R.

1996-01-01

A system and methodology were developed for the nondestructive qualitative and quantitative analysis of volatile emissions from hydroponically grown 'Waldmann's Green' leaf lettuce (Lactuca sativa L.). Photosynthetic photon flux (PPF), photoperiod, and temperature were automatically controlled and monitored in a growth chamber modified for the collection of plant volatiles. The lipoxygenase pathway products (Z)-3-hexenal, (Z)-3-hexenol, and (Z)-3-hexenyl acetate were emitted by lettuce plants after the transition from the light period to the dark period. The volatile collection system developed in this study enabled measurements of volatiles emitted by intact plants, from planting to harvest, under controlled environmental conditions.

Survey of ex situ fruit and leaf volatiles from several Pistacia cultivars grown in California.

PubMed

Roitman, James N; Merrill, Glory B; Beck, John J

2011-03-30

California is the second largest cultivator of pistachios, producing over 375 million pounds and a revenue of $787 million in 2009. Despite the agricultural and economic importance of pistachios, little is known regarding their actual volatile emissions, which are of interest owing to their potential roles as semiochemicals to insect pests. The ex situ volatile analysis of leaves from Pistacia atlantica, P. chinensis, P. lentiscus, P. palaestina, P. terebinthus, P. vera and P. weimannifolia demonstrated emission differences between species as well as between female and male leaves. Leaves from the female P. vera cultivars Bronte, Damghan, II, III, Kerman and Ohadi as well as fruits of P. atlantica, P. chinensis, P. lentiscus, P. palaestina, P. terebinthus and P. vera (cultivars II, III, Kaleh, Kerman, Momtaz and Ohadi) showed differences in the composition and relative quantity of major volatiles. The compounds in highest relative quantities from the various analyses were sabinene, Δ(3)-carene, β-myrcene, α-phellandrene, limonene, (Z)-ocimene, (E)-β-ocimene and α-terpinolene. This is the first ex situ survey of fruit and leaf volatile emissions from California-grown Pistacia species and a number of corresponding cultivars. The study provides an overview of the major and minor volatile emissions and also offers evidence of chemotypes based on monoterpenes. The results highlight the dissimilarity of major components detected between ex situ volatile collection and essential oil analysis. This article is a US Government work and is in the public domain in the USA. Published in 2011 by John Wiley & Sons, Ltd.

Volatile Constituents of Three Piper Species from Vietnam.

PubMed

Hieua, Le D; Hoic, Tran M; Thangda, Tran D; Ogunwande, Isiaka A

2015-11-01

The chemical compositions of the essential oils obtained by hydrodistillation of three Piper plants grown in Vietnam are reported. The analysis was achieved by means of gas chromatography with flame ionization detection (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). The main constituents of the leaf oil of Piper majusculum Blume were β-caryophyllene (20.7%), germacrene D (18.6%) and β-elemene (11.3%). The quantitatively significant compounds of the volatile oils of P. harmandii C. DC were sabinene (leaves, 14.5%; stems, 16.2%), benzyl benzoate (leaves, 20.0%; stems, 29.40%) and benzyl salicylate (leaves, 14.1%; stems, 24.3%). Also, α-cadinol (17.0%) was identified in large proportion in the leaf oil. However, sabinene (leaves, 17.9%; stems, 13.5%), benzyl benzoate (leaves, 20.5%; stems, 32.5%) and β-eudesmol (leaves, 13.8%; stems, 8.4%) were the main constituents of P. brevicaule C. DC. This is the first report on the volatile constituents of both P. harmandii and P. brevicaule.

Essential oil from leaves of Lippia dulcis grown in Colombia.

PubMed

Moreno-Murillo, Bárbara; Quijano-Célis, Clara; Romero, Arturo R; Pino, Jorge A

2010-04-01

The chemical composition of the volatile compounds from the leaves of Lippia dulcis Trev. (Verbenaceae) from Colombia was studied by GC and GC/MS. Forty volatile compounds were identified, of which the major ones were alpha-copaene (18.0%), beta-caryophyllene (17.8%), and delta-cadinene (14.7%). The sweet bisabolane sesquiterpenoid, hernandulcin, formed only 1.1% of the leaf oil.

Interannual variability of snowmelt in the Sierra Nevada and Rocky Mountains, United States: Examples from two alpine watersheds

NASA Astrophysics Data System (ADS)

Jepsen, Steven M.; Molotch, Noah P.; Williams, Mark W.; Rittger, Karl E.; Sickman, James O.

2012-02-01

The distribution of snow and the energy flux components of snowmelt are intrinsic characteristics of the alpine water cycle controlling the location of source waters and the effect of climate on streamflow. Interannual variability of these characteristics is relevant to the effect of climate change on alpine hydrology. Our objective is to characterize the interannual variability in the spatial distribution of snow and energy fluxes of snowmelt in watersheds of a maritime setting, Tokopah Basin (TOK) in California's southern Sierra Nevada, and a continental setting, Green Lake 4 Valley (GLV4) in Colorado's Front Range, using a 12 year database (1996-2007) of hydrometeorological observations and satellite-derived snow cover. Snowpacks observed in GLV4 exhibit substantially greater spatial variability than in TOK (0.75 versus 0.28 spatial coefficient of variation). In addition, modeling results indicate that the net turbulent energy flux contribution to snowmelt in GLV4 is, on average, 3 times greater in magnitude (mean 29% versus 10%) and interannual variability (standard deviation 17% versus 6%) than in TOK. These energy flux values exhibit strong seasonality, increasing as the melt season progresses to times later in the year (R2 = 0.54-0.77). This seasonality of energy flux appears to be associated with snowmelt rates that generally increase with onset date of melt (0.02 cm d-2). This seasonality in snowmelt rate, coupled to differences in hydrogeology, may account for the observed differences in correspondence between the timing of snowmelt and timing of streamflow in these watersheds.

Interannual variability of snowmelt in the Sierra Nevada and Rocky Mountains, United States: examples from two alpine watersheds

USGS Publications Warehouse

Jepsen, Steven M.; Molotch, Noah P.; Williams, Mark W.; Rittger, Karl E.; Sickman, James O.

2012-01-01

The distribution of snow and the energy flux components of snowmelt are intrinsic characteristics of the alpine water cycle controlling the location of source waters and the effect of climate on streamflow. Interannual variability of these characteristics is relevant to the effect of climate change on alpine hydrology. Our objective is to characterize the interannual variability in the spatial distribution of snow and energy fluxes of snowmelt in watersheds of a maritime setting, Tokopah Basin (TOK) in California's southern Sierra Nevada, and a continental setting, Green Lake 4 Valley (GLV4) in Colorado's Front Range, using a 12 year database (1996–2007) of hydrometeorological observations and satellite-derived snow cover. Snowpacks observed in GLV4 exhibit substantially greater spatial variability than in TOK (0.75 versus 0.28 spatial coefficient of variation). In addition, modeling results indicate that the net turbulent energy flux contribution to snowmelt in GLV4 is, on average, 3 times greater in magnitude (mean 29% versus 10%) and interannual variability (standard deviation 17% versus 6%) than in TOK. These energy flux values exhibit strong seasonality, increasing as the melt season progresses to times later in the year (R2 = 0.54–0.77). This seasonality of energy flux appears to be associated with snowmelt rates that generally increase with onset date of melt (0.02 cm d-2). This seasonality in snowmelt rate, coupled to differences in hydrogeology, may account for the observed differences in correspondence between the timing of snowmelt and timing of streamflow in these watersheds.

A major host plant volatile, 1-octen-3-ol, contributes to mating in the legume pod borer, Maruca vitrata (Fabricius) (Lepidoptera: Crambidae)

NASA Astrophysics Data System (ADS)

Bendera, M.; Ekesi, S.; Ndung'u, M.; Srinivasan, R.; Torto, B.

2015-10-01

Previous studies on the legume pod borer, Maruca vitrata Fabricius (Lepidoptera: Crambidae), a serious pest of cowpea, Vigna unguiculata (L.) Walp. (Fabales: Fabaceae), in sub-Saharan Africa have focused on sex pheromones, but the role of the host plant on sexual behavior has not been explored. We investigated this interaction in the laboratory using behavioral assays and chemical analyses. We found that the presence of cowpea seedlings and a dichloromethane extract of the leaf increased coupling in the legume pod borer by 33 and 61 %, respectively, compared to the control, suggesting the involvement of both contact and olfactory cues. We used coupled gas chromatography-electroantennographic detection (GC/EAD) and GC-mass spectrometry (GC/MS) to identify compounds from the cowpea leaf extract, detected by M. vitrata antenna. We found that the antennae of the insect consistently detected four components, with 1-octen-3-ol identified as a common and dominant component in both the volatiles released by the intact cowpea plant and leaf extract. We therefore investigated its role in the coupling of M. vitrata. In dose-response assays, 1-octen-3-ol increased coupling in M. vitrata with increasing dose of the compound compared to the control. Our results suggest that the cowpea volatile 1-octen-3-ol contributes to M. vitrata sexual behavior.

Above and belowground connections and species interactions: Controls over ecosystem fluxes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trowbridge, Amy Marie; Phillips, Richard; Stoy, Paul Christopher

The ultimate goal of this work was to quantify soil and volatile organic compound fluxes as a function of tree species and associated mycorrhizal associations in an intact forest, but also to describe the physical and biological factors that control these emissions. The results of this research lay the foundation toward an improved mechanistic understanding of carbon pathways, fluxes, and ecosystem function, ultimately improving the representation of forest ecosystems in Earth System models. To this end, a multidisciplinary approach was necessary to fill a critical gap in our understanding of how soil and root processes may influence whole-ecosystem carbon-based volatilemore » fluxes in the face of a rapidly changing climate. We developed a series of novel sampling protocols and coupled a variety of advanced analytical techniques, resulting in findings relevant across disciplines. Furthermore, we leveraged existing infrastructure, research sites, and datasets to design a low-cost exploratory project that links belowground processes, soil volatile emissions, and total ecosystem carbon budgets. Measurements from soil collars installed across a species/mycorrhizal gradient at the DOE-supported Moran Monroe State Forest Ameriflux tower site suggest that leaf litter is the primary source of belowground and forest floor volatile emissions, but the strength of this source is significantly affected not only by leaf litter type, but the strength of the soil as a sink. Results suggest that the strength of the sink is influenced by tree species-specific associated microbial communities that change throughout the season as a function of temperature, soil moisture, leaf litter inputs, and phenology. The magnitude of the observed volatile fluxes from the forest floor is small relative to total aboveground ecosystem flux, but the contribution of these emissions to volatile-mediated ecological interactions and soil processes (e.g. nitrification) varies substantially across the growing season. This research lays the foundation to answer important questions regarding the impacts of seasonality and forest composition on belowground volatile source-sink dynamics in mediating nutrient cycling and biogeochemistry dynamics—critical components of overall ecosystem functioning. In collaboration with the Environmental Simulations Unit (EUS) at the Helmholtz Zentrum in Munich, Germany (headed by Prof. Dr. Joerg-Peter Schinitzler), we investigated carbon investment in above and belowground plant volatile compounds in response to environmental conditions and mycorrhizal associations. Using the sophisticated phytotron facility and on-line trace gas instruments, we conducted controlled laboratory experiments that showed that biotic stresses, such as herbivore feeding, can alter the magnitude of belowground volatile emissions as well as carbon allocation towards these volatiles. We saw no effect of mycorrhizae on any induced response, suggesting that microbial effects were unrelated to source-sink dynamics driving terpene emissions. Furthermore, the results suggest that even though enzyme activity responsible for root volatile synthesis is up-regulated following herbivory, the sink strength of the soil can significantly impact what is measured at the soil/atmosphere interface and thereby what enters the atmosphere. This is important as scientists may be underestimating the magnitude of belowground volatile emissions and their influence on belowground interactions due to limitations associated with current sampling techniques. These key findings are being integrated with results from a hydroxyl radical reactivity-VOC campaign and a late season litter removal experiment to offer a comprehensive mechanistic understanding of the sources and controls over soil volatile emissions, particularly during times of the year when vegetative aboveground emissions are low (leaf senescence). Ultimately, these coupled field and laboratory experiments offer insights into seasonal dynamics of volatile emissions and the mechanisms that control carbon allocation to these compounds with an eye towards improving carbon budgets, nutrient cycling, and terrestrial ecosystem models.« less

Identification of volatiles in leaves of Alpinia zerumbet 'Variegata' using headspace solid-phase microextraction-gas chromatography-mass spectrometry.

PubMed

Chen, Jian Yan; Ye, Zheng Mei; Huang, Tian Yi; Chen, Xiao Dan; Li, Yong Yu; Wu, Shao Hua

2014-07-01

Alpinia zerumbet 'Variegata' is an aromatic medicinal plant, its foliage producing an intense, unique fragrant odor. This study identified 46 volatile compounds in the leaf tissue of this plant using headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The major compounds included 1, 8-cineole (43.5%), p-cymene (14.7%), humulene (5.5%), camphor (5.3%), linalool (4.7%), (E)-methyl cinnamate (3.8%), gamma-cadinene (3.3%), humulene oxide II (2.1%) and a-terpineol (1.5%). The majority of the volatiles were terpenoids of which oxygenated monoterpenes were the most abundant, accounting for 57.2% of the total volatiles. Alcohols made up the largest (52.8%) and aldehydes the smallest (0.2%) portions of the volatiles. Many bioactive compounds were present in the volatiles.

Responses of the two‐spotted oak buprestid, Agrilus biguttatus (Coleoptera: Buprestidae), to host tree volatiles

PubMed Central

Woodcock, Christine M; Sumner, Mary E; Caulfield, John C; Reed, Katy; Inward, Daegan JG; Leather, Simon R; Pickett, John A; Birkett, Michael A; Denman, Sandra

2016-01-01

Abstract BACKGROUND Agrilus bigutattus (Fabricius) is a forest pest of increasing importance in the United Kingdom. The larvae damage weakened native oaks and are thought to contribute to premature tree death. Suspected links with acute oak decline (AOD) are not yet confirmed, but AOD‐predisposed trees appear to become more susceptible to A. biguttatus attack. Thus, management may be necessary for control of this insect. To explore the possibility of monitoring beetle populations by baited traps, the host tree volatiles regulating A. biguttatus–oak interactions were studied. RESULTS Biologically active volatile organic compounds in dynamic headspace extracts of oak foliage and bark were identified initially by coupled gas chromatography–electroantennography (GC‐EAG) and GC–mass spectrometry (GC‐MS), and the structures were confirmed by GC coinjection with authentic compounds. Of two synthetic blends of these compounds comprising the active leaf volatiles, the simpler one containing three components evoked strongly positive behavioural responses in four‐arm olfactometer tests with virgin females and males, although fresh leaf material was more efficient than the blend. The other blend, comprising a five‐component mixture made up of bark volatiles, proved to be as behaviourally active for gravid females as bark tissue. CONCLUSIONS These initial results on A. biguttatus chemical ecology reveal aspects of the role of attractive tree volatiles in the host‐finding of beetles and underpin the development of semiochemically based surveillance strategies for this forest insect. © 2015 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:26663022

Constraints and opportunities for implementing nutrition-specific, agricultural and market-based approaches to improve nutrient intake adequacy among infants and young children in two regions of rural Kenya.

PubMed

Hotz, Christine; Pelto, Gretel; Armar-Klemesu, Margaret; Ferguson, Elaine F; Chege, Peter; Musinguzi, Enock

2015-12-01

Several types of interventions can be used to improve nutrient intake adequacy in infant and young child (IYC) diets, including fortified foods, home fortification, nutrition education and behaviour change communication (BCC) in addition to agricultural and market-based strategies. However, the appropriate selection of interventions depends on the social, cultural, physical and economic context of the population. Derived from two rural Kenyan populations, this analysis combined information from: (1) a quantitative analysis to derive a set of food-based recommendations (FBRs) to fill nutrient intake gaps in IYC diets and identify 'problem nutrients' for which intake gaps require solutions beyond currently available foods and dietary patterns, and (2) an ethnographic qualitative analysis to identify contextual factors posing opportunities or constraints to implementing the FBRs, including perceptions of cost, convenience, accessibility and appropriateness of the recommended foods for IYC diets and other social or physical factors that determine accessibility of those foods. Opportunities identified included BCC to increase the acceptability and utilisation of green leafy vegetables (GLV) and small fish and agronomic interventions to increase the productivity of GLV and millet. Value chains for millet, beans, GLV, milk and small fish should be studied for opportunities to increase their accessibility in local markets. Processor-level interventions, such as partially cooked fortified dry porridge mixes or unfortified cereal mixes incorporating millet and beans, may increase the accessibility of foods that provide increased amounts of the problem nutrients. Multi-sectoral actors and community stakeholders should be engaged to assess the feasibility of implementing these locally appropriate strategies. © 2015 John Wiley & Sons Ltd.

Essential oil of Galinsoga parviflora leaves from Colombia.

PubMed

Pino, Jorge A; Gaviria, Mauricio; Quevedo-Vega, Juana; García-Lesmes, Laura; Quijano-Celis, Clara E

2010-11-01

The chemical composition of the volatile compounds from the leaves of Galinsoga parviflora Cav. (Asteraceae) from Colombia was studied by GC and GC/MS. Eighty-eight volatile compounds were identified, of which the major ones were (Z)-3-hexen-1-ol (21.7%), beta-caryophyllene (12.4%), and 6-demethoxy-ageratochrome (14%). The leaf oil presented antimicrobial activities against the Gram-positive bacteria Staphylococcus aureus and Bacillus cereus.

Herbivory by leaf-cutter ants changes the glandular trichomes density and the volatile components in an aromatic plant model

PubMed Central

Mayo Marques, Marcia Ortiz; Maria Rodrigues, Tatiane

2017-01-01

Abstract Herbivory can induce several structural and functional alterations in the plant secretory system. Glandular trichomes are the main sites of production of volatile organic compounds (VOCs) with several chemical properties in Lamiaceae species. Ocimum species usually have three morphotypes of glandular trichomes (morphotype I is peltate and has a wide four-celled head; morphotype II is capitate and has a unicellular head; and morphotype III is capitate with a bicellular head) which produce a great amount of terpenes, although other chemical categories of substances are also produced. Despite the abundance of trichomes producing important anti-herbivory components in their leaves, the association between Ocimum species and leaf-cutter ants has been commonly registered in Brazil. We investigated the effect of leaf-cutter ant attack on the density of the glandular trichomes and on the chemistry of the VOCs released from leaves of O. gratissimum. Plants were subjected to Acromyrmex rugosus attack until 90 % of leaves were removed. After 40 days from the leaf-cutter attack, both treatments were sampled. The glandular trichome density was analysed by scanning electron microscopy. The VOCs were extracted utilizing headspace solid-phase microextraction (HS-SPME) technique and analysed by gas chromatography. Generally, the density of glandular trichomes increased in the adaxial leaf surface of the attacked plants. However, we bring novelties on this topic since we analysed the density of each morphotype separately. The morphotype I decreased in the abaxial leaf surface, and increased in the adaxial leaf surface; the morphotype II increased in both leaf surfaces; and the morphotype III decreased in the abaxial leaf surface and remained constant in the adaxial leaf surface of attacked plants. In leaves of attacked plants, the (Z)-β-ocimene increased by 50 %, the α-selinene by 13 % and the germacrene D by 126 %, whereas the eugenol decreased by 70 %. Our data point to a differential response of each glandular morphotype in O. gratissimum and are consistent with the idea of a compartmentalization of functions among the different glandular morphotypes in the plant defence against environmental factors. PMID:29218139

Influence of microwave frequency electromagnetic radiation on terpene emission and content in aromatic plants

PubMed Central

Soran, Maria-Loredana; Stan, Manuela; Niinemets, Ülo; Copolovici, Lucian

2015-01-01

Influence of environmental stress factors on both crop and wild plants of nutritional value is an important research topic. The past research has focused on rising temperatures, drought, soil salinity and toxicity, but the potential effects of increased environmental contamination by human-generated electromagnetic radiation on plants have little been studied. Here we studied the influence of microwave irradiation at bands corresponding to wireless router (WLAN) and mobile devices (GSM) on leaf anatomy, essential oil content and volatile emissions in Petroselinum crispum, Apium graveolens and Anethum graveolens. Microwave irradiation resulted in thinner cell walls, smaller chloroplasts and mitochondria, and enhanced emissions of volatile compounds, in particular, monoterpenes and green leaf volatiles. These effects were stronger for WLAN-frequency microwaves. Essential oil content was enhanced by GSM-frequency microwaves, but the effect of WLAN-frequency microwaves was inhibitory. There was a direct relationship between microwave-induced structural and chemical modifications of the three plant species studied. These data collectively demonstrate that human-generated microwave pollution can potentially constitute a stress to the plants. PMID:25050479

Functional hyper-IL-6 from vaccinia virus-colonized tumors triggers platelet formation and helps to alleviate toxicity of mitomycin C enhanced virus therapy

PubMed Central

2012-01-01

Background Combination of oncolytic vaccinia virus therapy with conventional chemotherapy has shown promise for tumor therapy. However, side effects of chemotherapy including thrombocytopenia, still remain problematic. Methods Here, we describe a novel approach to optimize combination therapy of oncolytic virus and chemotherapy utilizing virus-encoding hyper-IL-6, GLV-1h90, to reduce chemotherapy-associated side effects. Results We showed that the hyper-IL-6 cytokine was successfully produced by GLV-1h90 and was functional both in cell culture as well as in tumor-bearing animals, in which the cytokine-producing vaccinia virus strain was well tolerated. When combined with the chemotherapeutic mitomycin C, the anti-tumor effect of the oncolytic virotherapy was significantly enhanced. Moreover, hyper-IL-6 expression greatly reduced the time interval during which the mice suffered from chemotherapy-induced thrombocytopenia. Conclusion Therefore, future clinical application would benefit from careful investigation of additional cytokine treatment to reduce chemotherapy-induced side effects. PMID:22236378

Attraction of Three Mirid Predators to Tomato Infested by Both the Tomato Leaf Mining Moth Tuta absoluta and the Whitefly Bemisia tabaci.

PubMed

Silva, Diego B; Bueno, Vanda H P; Van Loon, Joop J A; Peñaflor, Maria Fernanda G V; Bento, José Maurício S; Van Lenteren, Joop C

2018-01-01

Plants emit volatile compounds in response to insect herbivory, which may play multiple roles as defensive compounds and mediators of interactions with other plants, microorganisms and animals. Herbivore-induced plant volatiles (HIPVs) may act as indirect plant defenses by attracting natural enemies of the attacking herbivore. We report here the first evidence of the attraction of three Neotropical mirid predators (Macrolophus basicornis, Engytatus varians and Campyloneuropsis infumatus) toward plants emitting volatiles induced upon feeding by two tomato pests, the leaf miner Tuta absoluta and the phloem feeder Bemisia tabaci, in olfactometer bioassays. Subsequently, we compared the composition of volatile blends emitted by insect-infested tomato plants by collecting headspace samples and analyzing them with GC-FID and GC-MS. Egg deposition by T. absoluta did not make tomato plants more attractive to the mirid predators than uninfested tomato plants. Macrolophus basicornis is attracted to tomato plants infested with either T. absoluta larvae or by a mixture of B. tabaci eggs, nymphs and adults. Engytatus varians and C. infumatus responded to volatile blends released by tomato plants infested with T. absoluta larvae over uninfested plants. Also, multiple herbivory by T. absoluta and B. tabaci did not increase the attraction of the mirids compared to infestation with T. absoluta alone. Terpenoids represented the most important class of compounds in the volatile blends and there were significant differences between the volatile blends emitted by tomato plants in response to attack by T. absoluta, B. tabaci, or by both insects. We, therefore, conclude that all three mirids use tomato plant volatiles to find T. absoluta larvae. Multiple herbivory did neither increase, nor decrease attraction of C. infumatus, E. varians and M. basicornis. By breeding for higher rates of emission of selected terpenes, increased attractiveness of tomato plants to natural enemies may improve the effectiveness of biological control.

Evidence for a volatile pheromone in Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) that increases attraction to a host foliar volatile.

PubMed

Silk, Peter J; Ryall, Krista; Mayo, Peter; Lemay, Matthew A; Grant, Gary; Crook, Damon; Cossé, Allard; Fraser, Ivich; Sweeney, Jon D; Lyons, D Barry; Pitt, Doug; Scarr, Taylor; Magee, David

2011-08-01

Analysis by gas chromatography/mass spectrometry (GC/MS) of volatiles from virgin female emerald ash borer, Agrilus planipennis Fairmaire confirmed the emission of (3Z)-lactone [(3Z)-dodecen-12-olide] but not its geometric isomer, (3E)-lactone [(3E)-dodecen-12-olide]. Gas chromatographic/electroantennographic (GC/EAD) analysis of synthetic (3Z)-lactone, which contained 10% (3E)-lactone, showed a strong response of male and female antennae to both isomers. EAG analysis with 0.01- to 100-μg dosages showed a positive dose response, with females giving significantly higher responses than males. In field experiments with sticky purple prism traps, neither lactone isomer affected catches when combined with ash foliar or cortical volatiles (green leaf volatiles or Phoebe oil, respectively). However, on green prism traps, the (3Z)-lactone significantly increased capture of male A. planipennis when traps were deployed in the canopy. Captures of males on traps with both (3E)-lactone and (3Z)-hexenol or with (3Z)-lactone and (3Z)-hexenol were increased by 45-100%, respectively, compared with traps baited with just (3Z)-hexenol. In olfactometer bioassays, males were significantly attracted to (3E)-lactone, but not the (3Z)-lactone or a 60:40 (3E):(3Z) blend. The combination of either (3E)- or (3Z)-lactone with Phoebe oil was not significantly attractive to males. Males were highly attracted to (3Z)-hexenol and the (3Z)-lactone + (3Z)-hexenol combination, providing support for the field trapping results. These data are the first to demonstrate increased attraction with a combination of a pheromone and a green leaf volatile in a Buprestid species.

The Role of Mycorrhizal Associations in Controlling Biogenic Volatile Organic Carbon Flux From a Temperate Deciduous Forest

NASA Astrophysics Data System (ADS)

Cook, A. A.; Trowbridge, A.; Jacobs, L. M.; Stoy, P. C.; Stevens, P. S.; Phillips, R.

2016-12-01

The sources of and controls over biogenic volatile organic compound (bVOC) fluxes between terrestrial ecosystems and the atmosphere remains poorly understood. Ecosystem bVOC flux models rarely include contributions from leaf litter and soils despite recent findings demonstrating that they can be nontrivial components of total ecosystem bVOC flux. Other recent studies have demonstrated the central role of arbuscular (AM) versus ectomycorrhizal (ECM) fungi in determining litter quality and soil biogeochemistry. Here, we quantify the role of mycorrhizal associations in controlling soil and leaf litter bVOC flux during the growing to non-growing season transition at the Morgan Monroe State Forest Ameriflux Core research site in Indiana, USA. We hypothesize that (1) total bVOC emissions will be greater from ECM plots due to larger belowground microbial biomass, and (2) fast-decomposing litter within the AM-dominated plots will result in an ephemeral pulse in bVOC emissions later in the season. AM and ECM-dominated forest soils were a net bVOC sink early in the growing season following leaf-out, but were net sources during the leaf-fall period in October. In the absence of leaf litter, soils dominated by ECM were a large sink of bVOCs, but leaf litter inputs resulted in a net source, suggesting that leaf litter and not merely soil microbial biomass is critical for understanding hypothesis (1). Temperature explains 57% (21%) of the variability of methanol flux - the bVOC of greatest quantity - in ECM (AM)-dominated plots. Non-methanol bVOC flux is only related to soil temperature in the Fall in ECM-dominated plots, where it explains 71% of the variability. Results are consistent with large methanol efflux with fresh litter after leaf-fall, especially in ECM plots (contrary to hypothesis 2), but net uptake with strong temperature-dependence during the growing season. Seasonality, phenology (including leaf litter dynamics) and mycorrhizal associations should be taken into account to accurately determine the relative contribution of forest soils to ecosystem bVOC fluxes in temperate forests and their sensitivity to environmental drivers.

Chemical composition and phytotoxicity of volatile essential oil from intact and fallen leaves of Eucalyptus citriodora.

PubMed

Batish, Daizy R; Singh, Harminder P; Setia, Nidhi; Kaur, Shalinder; Kohli, Ravinder K

2006-01-01

A total of 23 volatile constituents was identified and characterized by GC and GC-MS in the volatile essential oil extracted from intact (juvenile and adult) and fallen (senescent and leaf litter) leaves of lemon-scented eucalyptus (Eucalyptus citriodora Hook.). The leaves differed in their pigment, water and protein content, and C/N ratio. The oils were, in general, monoterpenoid in nature with 18 monoterpenes and 5 sesquiterpenes. However, a great variability in the amount of essential oils and their individual constituents was observed in different leaf tissues. The amount was maximum in the senescent leaves collected from the floor of the tree closely followed by that from juvenile leaves. In all, 19 constituents were identified in oil from juvenile and senescent leaves compared to 23 in adult leaves and 20 in leaf litter, respectively. Citronellal, a characteristic monoterpene of the oil reported hitherto was found to be more (77-78%) in the juvenile and senescent leaves compared to 48 and 54%, respectively, in the adult leaves and leaf litter. In the adult leaves, however, the content of citronellol--another important monoterpene-- was very high (21.9%) compared to other leaf types (7.8-12.2%). Essential oil and its two major monoterpenes viz. citronellal and citronellol were tested for their phytotoxicity against two weeds (Amaranthus viridis and Echinochloa crus-galli) and two crops (Triticum aestivum and Oryza sativa) under laboratory conditions. A difference in the phytotoxicity, measured in terms of seedling length and dry weight, of oil from different leaves and major monoterpenes was observed. Oil from adult leaves was found to be most phytotoxic although it occurs in smaller amount (on unit weight basis). The different toxicity of different oil types was due to the relative amount of individual monoterpenes present in the oil, their solubility and interactive action. The study concludes that oil from senescent and juvenile leaves being rich in citronellal could be used as commercial source of citronellal whereas that from adult leaves for weed management programmes as it was the most phytotoxic.

Climate change alters leaf anatomy, but has no effects on volatile emissions from Arctic plants.

PubMed

Schollert, Michelle; Kivimäenpää, Minna; Valolahti, Hanna M; Rinnan, Riikka

2015-10-01

Biogenic volatile organic compound (BVOC) emissions are expected to change substantially because of the rapid advancement of climate change in the Arctic. BVOC emission changes can feed back both positively and negatively on climate warming. We investigated the effects of elevated temperature and shading on BVOC emissions from arctic plant species Empetrum hermaphroditum, Cassiope tetragona, Betula nana and Salix arctica. Measurements were performed in situ in long-term field experiments in subarctic and high Arctic using a dynamic enclosure system and collection of BVOCs into adsorbent cartridges analysed by gas chromatography-mass spectrometry. In order to assess whether the treatments had resulted in anatomical adaptations, we additionally examined leaf anatomy using light microscopy and scanning electron microscopy. Against expectations based on the known temperature and light-dependency of BVOC emissions, the emissions were barely affected by the treatments. In contrast, leaf anatomy of the studied plants was significantly altered in response to the treatments, and these responses appear to differ from species found at lower latitudes. We suggest that leaf anatomical acclimation may partially explain the lacking treatment effects on BVOC emissions at plant shoot-level. However, more studies are needed to unravel why BVOC emission responses in arctic plants differ from temperate species. © 2015 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.

Biological, medicinal and toxicological significance of Eucalyptus leaf essential oil: a review.

PubMed

Dhakad, Ashok K; Pandey, Vijay V; Beg, Sobia; Rawat, Janhvi M; Singh, Avtar

2018-02-01

The genus Eucalyptus L'Heritier comprises about 900 species, of which more than 300 species contain volatile essential oil in their leaves. About 20 species, within these, have a high content of 1,8-cineole (more than 70%), commercially used for the production of essential oils in the pharmaceutical and cosmetic industries. However, Eucalyptus is extensively planted for pulp, plywood and solid wood production, but its leaf aromatic oil has astounding widespread biological activities, including antimicrobial, antiseptic, antioxidant, chemotherapeutic, respiratory and gastrointestinal disorder treatment, wound healing, and insecticidal/insect repellent, herbicidal, acaricidal, nematicidal, and perfumes, soap making and grease remover. In the present review, we have made an attempt to congregate the biological ingredients of leaf essential oil, leaf oil as a natural medicine, and pharmacological and toxicological values of the leaf oil of different Eucalyptus species worldwide. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Ginseng leaf-stem: bioactive constituents and pharmacological functions

PubMed Central

Wang, Hongwei; Peng, Dacheng; Xie, Jingtian

2009-01-01

Ginseng root is used more often than other parts such as leaf stem although extracts from ginseng leaf-stem also contain similar active ingredients with pharmacological functions. Ginseng's leaf-stems are more readily available at a lower cost than its root. This article reviews the pharmacological effects of ginseng leaf-stem on some diseases and adverse effects due to excessive consumption. Ginseng leaf-stem extract contains numerous active ingredients, such as ginsenosides, polysaccharides, triterpenoids, flavonoids, volatile oils, polyacetylenic alcohols, peptides, amino acids and fatty acids. The extract contains larger amounts of the same active ingredients than the root. These active ingredients produce multifaceted pharmacological effects on the central nervous system, as well as on the cardiovascular, reproductive and metabolic systems. Ginseng leaf-stem extract also has anti-fatigue, anti-hyperglycemic, anti-obesity, anti-cancer, anti-oxidant and anti-aging properties. In normal use, ginseng leaf-stem extract is quite safe; adverse effects occur only when it is over dosed or is of poor quality. Extracts from ginseng root and leaf-stem have similar multifaceted pharmacological activities (for example central nervous and cardiovascular systems). In terms of costs and source availability, however, ginseng leaf-stem has advantages over its root. Further research will facilitate a wider use of ginseng leaf-stem. PMID:19849852

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lincoln, D.E.

Preliminary analysis of two populations of Artemisia tridentata compared leaf chemical and physiological characteristics which influence herbivores. The proportion of sixteen of the volatile compounds differed significantly between the two populations; however, total yield of volatiles did not. This initial survey established the reliability of the procedure to quantitatively monitor plant responses to CO/sub 2/ enrichment and suggests that test samples be restricted to a single population. Four sesquiterpene lactones have been selected for the experimental quantitative HPLC analysis; all peaks have been assigned identities and have demonstrated high degree of reproducibility. Growth of Artemisia under high and low lightmore » at three CO/sub 2/ levels demonstrated that this species also undergoes a ''dilution'' of the leaf carbon content and is useful as test species for herbivory response to CO/sub 2/ induced effects. The initial experiment also showed that high irradiance is a necessary growth condition. 10 refs.« less

Influence of volatile terpenes on the capacity of leaves to uptake and detoxify ozone. (Invited)

NASA Astrophysics Data System (ADS)

Loreto, F.; Fares, S.

2009-12-01

Tropospheric ozone is considered the most dangerous air pollutant for plant ecosystems, and its concentration is increasing throughout the earth. Oxidative damage takes place when ozone penetrates inside the leaves through the stomata and the cuticles. The latest guidelines suggest considering the dose entering stomata to evaluate ozone risk on vegetation. We have shown that this metric may not consider important detoxification mechanisms activated by the production of volatile antioxidants, especially terpenes. We review here how volatile terpenes may increase ozone uptake by leaves yet reducing the risk of damage to internal leaf structures. We also argue that volatile terpene production by plants phases-in with episodes on high ozone whereas other detoxification mechanisms are phased-out. Our results suggests that volatile isoprenoids play a major role in determining the capacity of ozone removal and detoxification by vegetation.

Sensory characteristics and volatile profiles of parsley ( Petroselinum crispum [Mill.] Nym.) in correlation to resistance properties against Septoria Blight ( Septoria petroselini ).

PubMed

Ulrich, Detlef; Bruchmüller, Tobias; Krüger, Hans; Marthe, Frank

2011-10-12

Sixteen different genotypes of parsley, including two cultivars, six populations, and eight inbred lines, were investigated regarding their sensory characteristics in relation to the volatile patterns and resistance to Septoria petroselini . The sensory quality was determined by a combination of profile analysis and preference test, whereas the volatile patterns were analyzed by headspace-SPME-GC of leaf homogenates with subsequent nontargeted data processing to prevent a possible overlooking of volatile compounds. The more resistant genotypes are characterized by several negative sensory characteristics such as bitter, grassy, herbaceous, pungent, chemical, and harsh. In contrast, the contents of some volatile compounds correlate highly and significantly either with resistance (e.g., hexanal and α-copaene) or with susceptibility (e.g., p-menthenol). Some of these compounds with very strong correlation to resistance are still unidentified and are presumed to act as resistance markers.

Green Leaf Volatiles: A Plant’s Multifunctional Weapon against Herbivores and Pathogens

PubMed Central

Scala, Alessandra; Allmann, Silke; Mirabella, Rossana; Haring, Michel A.; Schuurink, Robert C.

2013-01-01

Plants cannot avoid being attacked by an almost infinite number of microorganisms and insects. Consequently, they arm themselves with molecular weapons against their attackers. Plant defense responses are the result of a complex signaling network, in which the hormones jasmonic acid (JA), salicylic acid (SA) and ethylene (ET) are the usual suspects under the magnifying glass when researchers investigate host-pest interactions. However, Green Leaf Volatiles (GLVs), C6 molecules, which are very quickly produced and/or emitted upon herbivory or pathogen infection by almost every green plant, also play an important role in plant defenses. GLVs are semiochemicals used by insects to find their food or their conspecifics. They have also been reported to be fundamental in indirect defenses and to have a direct effect on pests, but these are not the only roles of GLVs. These volatiles, being probably one of the fastest weapons exploited, are also able to directly elicit or prime plant defense responses. Moreover, GLVs, via crosstalk with phytohormones, mostly JA, can influence the outcome of the plant’s defense response against pathogens. For all these reasons GLVs should be considered as co-protagonists in the play between plants and their attackers. PMID:23999587

Sensory and Instrumental Flavor Changes in Green Tea Brewed Multiple Times

PubMed Central

Lee, Jeehyun; Chambers, Delores; Chambers, Edgar

2013-01-01

Green teas in leaf form are brewed multiple times, a common selling point. However, the flavor changes, both sensory and volatile compounds, of green teas that have been brewed multiple times are unknown. The objectives of this study were to determine how the aroma and flavor of green teas change as they are brewed multiple times, to determine if a relationship exists between green tea flavors and green tea volatile compounds, and to suggest the number of times that green tea leaves can be brewed. The first and second brews of the green tea samples provided similar flavor intensities. The third and fourth brews provided milder flavors and lower bitterness and astringency when measured using descriptive sensory analysis. In the brewed liquor of green tea mostly linalool, nonanal, geraniol, jasmone, and β-ionone volatile compounds were present at low levels (using gas chromatography-mass spectrometry). The geraniol, linalool, and linalool oxide compounds in green tea may contribute to the floral/perfumy flavor. Green teas in leaf form may be brewed up to four times: the first two brews providing stronger flavor, bitterness, and astringency whereas the third and fourth brews will provide milder flavor, bitterness, and astringency. PMID:28239138

Leaf level emissions of volatile organic compounds (VOC) from some Amazonian and Mediterranean plants

NASA Astrophysics Data System (ADS)

Bracho-Nunez, A.; Knothe, N. M.; Welter, S.; Staudt, M.; Costa, W. R.; Liberato, M. A. R.; Piedade, M. T. F.; Kesselmeier, J.

2012-11-01

As volatile organic compounds (VOCs) significantly affect atmospheric chemistry (oxidative capacity) and physics (secondary organic aerosol formation and effects), emission inventories defining regional and global biogenic VOC emission strengths are important. The aim of this work was to achieve a description of VOC emissions from poorly described tropical vegetation to be compared with the quite well investigated and highly heterogeneous emissions from Mediterranean vegetation. For this task, common plant species of both ecosystems were investigated. Sixteen plant species from the Mediterranean area, which is known for its special diversity in VOC emitting plant species, were chosen. In contrast, little information is currently available regarding emissions of VOCs from tropical tree species at the leaf level. Twelve plant species from different environments of the Amazon basin, i.e. Terra firme, Várzea and Igapó, were screened for emission of VOCs at leaf level with a branch enclosure system. Analysis of the volatile organics was performed online by a proton-transfer-reaction mass spectrometer (PTR-MS) and offline by collection on adsorbent tubes and subsequent gas chromatographic analysis. Isoprene was quantitatively the most dominant compound emitted followed by monoterpenes, methanol and acetone. Most of the Mediterranean species emitted a variety of monoterpenes, whereas only five tropical species were monoterpene emitters exhibiting a quite conservative emission pattern (α-pinene > limonene > sabinene > β-pinene). Mediterranean plants showed additional emissions of sesquiterpenes, whereas in the case of plants from the Amazon region no sesquiterpenes were detected probably due to a lack of sensitivity in the measuring systems. On the other hand methanol emissions, an indicator of growth, were common in most of the tropical and Mediterranean species. A few species from both ecosystems showed acetone emissions. The observed heterogeneous emissions including reactive VOC species which are not easily detected by flux measurements, give reason to perform more screening at leaf level and, whenever possible, within the forests under ambient conditions.

Orientation of Anopheles gambiae (Diptera: Culicidae) to Plant-Host Volatiles in a Novel Diffusion-Cage Olfactometer

PubMed Central

Otienoburu, Philip E.; Nikbakhtzadeh, Mahmood R.; Foster, Woodbridge A.

2016-01-01

A novel diffusion-cage olfactometer tested the responses of Anopheles gambiae Giles to plant volatiles. Green-leaf volatiles are often released from cut or injured plant tissue and may alter the headspace of plants used in olfactometer assays. The diffusion-cage olfactometer is designed for use with whole, intact plants, hence giving a more realistic behavioral assay. Its simple plastic construction, ease of assembly, and accommodation to whole plants makes it a useful tool for measuring mosquito orientation to plant volatiles within large enclosures. We compared its performance to that of the more commonly used T-tube wind-tunnel olfactometer, by testing the orientation of mosquitoes to volatiles of a few prevalent plants of eastern Africa reportedly utilized by An. gambiae for sugar: Parthenium hysterophorus (Asteraceae), Ricinus communis (Euphorbiaceae), Lantana camara (Verbenaceae), and Senna occidentalis (Fabaceae). Results indicate that the diffusion-cage olfactometer is an effective alternative to conventional wind-tunnel olfactometers, to test mosquito orientation to plant volatiles under seminatural conditions. PMID:26502752

Light Quality Dependent Changes in Morphology, Antioxidant Capacity, and Volatile Production in Sweet Basil (Ocimum basilicum)

PubMed Central

Carvalho, Sofia D.; Schwieterman, Michael L.; Abrahan, Carolina E.; Colquhoun, Thomas A.; Folta, Kevin M.

2016-01-01

Narrow-bandwidth light treatments may be used to manipulate plant growth, development and metabolism. In this report LED-based light treatments were used to affect yield and metabolic content of sweet basil (Ocimum basilicum L. cv “Ceasar”) grown in controlled environments. This culinary herb produces an aroma highly appreciated by consumers, primarily composed of terpenes/terpenoids, phenylpropanoids, and fatty-acid- derived volatile molecules. Basil plants were grown under narrow-bandwidth light conditions, and leaf area, height, mass, antioxidant capacity and volatile emissions were measured at various time points. The results indicate reproducible significant differences in specific volatiles, and in biochemical classes of volatiles, compared to greenhouse grown plants. For example, basil plants grown under blue/red/yellow or blue/red/green wavelengths emit higher levels of a subset of monoterpenoid volatiles, while a blue/red/far-red treatment leads to higher levels of most sesquiterpenoid volatile molecules. Specific light treatments increase volatile content, mass, and antioxidant capacity. The results show that narrow-bandwidth illumination can induce discrete suites of volatile classes that affect sensory quality in commercial herbs, and may be a useful tool in improving commercial production. PMID:27635127

Light Quality Dependent Changes in Morphology, Antioxidant Capacity, and Volatile Production in Sweet Basil (Ocimum basilicum).

PubMed

Carvalho, Sofia D; Schwieterman, Michael L; Abrahan, Carolina E; Colquhoun, Thomas A; Folta, Kevin M

2016-01-01

Narrow-bandwidth light treatments may be used to manipulate plant growth, development and metabolism. In this report LED-based light treatments were used to affect yield and metabolic content of sweet basil (Ocimum basilicum L. cv "Ceasar") grown in controlled environments. This culinary herb produces an aroma highly appreciated by consumers, primarily composed of terpenes/terpenoids, phenylpropanoids, and fatty-acid- derived volatile molecules. Basil plants were grown under narrow-bandwidth light conditions, and leaf area, height, mass, antioxidant capacity and volatile emissions were measured at various time points. The results indicate reproducible significant differences in specific volatiles, and in biochemical classes of volatiles, compared to greenhouse grown plants. For example, basil plants grown under blue/red/yellow or blue/red/green wavelengths emit higher levels of a subset of monoterpenoid volatiles, while a blue/red/far-red treatment leads to higher levels of most sesquiterpenoid volatile molecules. Specific light treatments increase volatile content, mass, and antioxidant capacity. The results show that narrow-bandwidth illumination can induce discrete suites of volatile classes that affect sensory quality in commercial herbs, and may be a useful tool in improving commercial production.

Priming of Wheat with the Green Leaf Volatile Z-3-Hexenyl Acetate Enhances Defense against Fusarium graminearum But Boosts Deoxynivalenol Production1

PubMed Central

Ameye, Maarten; Audenaert, Kris; De Zutter, Nathalie; Steppe, Kathy; Van Meulebroek, Lieven; Vanhaecke, Lynn; De Vleesschauwer, David; Haesaert, Geert; Smagghe, Guy

2015-01-01

Priming refers to a mechanism whereby plants are sensitized to respond faster and/or more strongly to future pathogen attack. Here, we demonstrate that preexposure to the green leaf volatile Z-3-hexenyl acetate (Z-3-HAC) primed wheat (Triticum aestivum) for enhanced defense against subsequent infection with the hemibiotrophic fungus Fusarium graminearum. Bioassays showed that, after priming with Z-3-HAC, wheat ears accumulated up to 40% fewer necrotic spikelets. Furthermore, leaves of seedlings showed significantly smaller necrotic lesions compared with nonprimed plants, coinciding with strongly reduced fungal growth in planta. Additionally, we found that F. graminearum produced more deoxynivalenol, a mycotoxin, in the primed treatment. Expression analysis of salicylic acid (SA) and jasmonic acid (JA) biosynthesis genes and exogenous methyl salicylate and methyl jasmonate applications showed that plant defense against F. graminearum is sequentially regulated by SA and JA during the early and later stages of infection, respectively. Interestingly, analysis of the effect of Z-3-HAC pretreatment on SA- and JA-responsive gene expression in hormone-treated and pathogen-inoculated seedlings revealed that Z-3-HAC boosts JA-dependent defenses during the necrotrophic infection stage of F. graminearum but suppresses SA-regulated defense during its biotrophic phase. Together, these findings highlight the importance of temporally separated hormone changes in molding plant health and disease and support a scenario whereby the green leaf volatile Z-3-HAC protects wheat against Fusarium head blight by priming for enhanced JA-dependent defenses during the necrotrophic stages of infection. PMID:25713338

DETECTION AND COMPARISON OF GIARDIAVIRUS (GLV) FROM DIFFERENT ASSEMBLAGES OF GIARDIA DUODENALIS

USDA-ARS?s Scientific Manuscript database

Five assemblages of Giardia were identified from cysts in cattle, dog, cat, sheep, and reindeer feces using ribosomal DNA (rDNA) sequencing. Assemblage A was present in cattle and reindeer feces, Assemblages C and D were present in dog feces, Assemblage E was present in cattle and sheep feces, and ...

Predicting community composition from pairwise interactions

NASA Astrophysics Data System (ADS)

Friedman, Jonathan; Higgins, Logan; Gore, Jeff

The ability to predict the structure of complex, multispecies communities is crucial for understanding the impact of species extinction and invasion on natural communities, as well as for engineering novel, synthetic communities. Communities are often modeled using phenomenological models, such as the classical generalized Lotka-Volterra (gLV) model. While a lot of our intuition comes from such models, their predictive power has rarely been tested experimentally. To directly assess the predictive power of this approach, we constructed synthetic communities comprised of up to 8 soil bacteria. We measured the outcome of competition between all species pairs, and used these measurements to predict the composition of communities composed of more than 2 species. The pairwise competitions resulted in a diverse set of outcomes, including coexistence, exclusion, and bistability, and displayed evidence for both interference and facilitation. Most pair outcomes could be captured by the gLV framework, and the composition of multispecies communities could be predicted for communities composed solely of such pairs. Our results demonstrate the predictive ability and utility of simple phenomenology, which enables accurate predictions in the absence of mechanistic details.

Headspace volatiles from 52 oak species advertise induction, species identity, and evolution, but not defense.

PubMed

Pearse, Ian S; Gee, Wai S; Beck, John J

2013-01-01

Leaf volatiles convey information about a plant to other organisms in their proximity. Despite increasing interest in understanding the relevance of volatile emissions for particular ecological interactions, there has been relatively little effort to assess generally what information volatile profiles transmit. We surveyed the volatile profiles of wounded and unwounded leaves of 52 oak (Quercus) species. We used phylogenetic comparison and multivariate techniques to assess in what circumstances oak individuals advertised their species identity, evolutionary history, direct defenses, or damage. We found that both species identity and evolutionary history were advertised when leaves were wounded, but species could not be differentiated by odor when leaves were not wounded. Various fatty-acid derivative compounds showed the strongest phylogenetic signal suggesting that they may best disclose taxonomic affiliations in oaks. We tested whether oak volatile composition or diversity advertised high defensive investment, but we found no evidence for this. Wounded leaves disclose much about an oak species' identity and taxonomic affiliation, but unwounded leaves do not. This is consistent with the idea that volatile information is targeted toward natural enemy recruitment.

Olfactory responses of Plutella xylostella natural enemies to host pheromone, larval frass, and green leaf cabbage volatiles.

PubMed

Reddy, G V P; Holopainen, J K; Guerrero, A

2002-01-01

The parasitoids Trichogramma chilonis (Hymenoptera: Trichogrammatidae) and Cotesia plutellae (Hymenoptera: Braconidae), and the predator Chrysoperla carnea (Neuroptera: Chrysopidae), are potential biological control agents for the diamondback moth, Plutella xylostella (Lepidoptera: Yponomeutidae). We present studies on the interactions between these bioagents and various host-associated volatiles using a Y olfactometer. T chilonis was attracted to a synthetic pheromone blend (Z11-16:Ald, Z11-16:Ac, and Z11-16:OH in a 1:1:0.01 ratio), to Z11-16:Ac alone, and to a 1:1 blend of Z11-16:Ac and Z11-16:Ald. C. plutellae responded to the blend and to Z11-16:Ac and Z11-16:Ald. Male and female C. carnea responded to the blend and to a 1:1 blend of the major components of the pheromone, although no response was elicited by single compounds. Among the four host larval frass volatiles tested (dipropyl disulfide, dimethyl disulfide, allyl isothiocyanate, and dimethyl trisulfide), only allyl isothiocyanate elicited significant responses in the parasitoids and predator, but C. plutellae and both sexes of C. carnea did respond to all four volatiles. Among the green leaf volatiles of cabbage (Brassica oleracea subsp. capitata), only Z3-6:Ac elicited significant responses from T. chilonis, C. plutellae, and C. carnea, but C. plutellae also responded to E2-6:Ald and Z3-6:OH. When these volatiles were blended with the pheromone, the responses were similar to those elicited by the pheromone alone, except for C. carnea males, which had an increased response. The effect of temperature on the response of the biological agents to a mixture of the pheromone blend and Z3-6:Ac was also studied. T. chilonis was attracted at temperatures of 25-35 degrees C, while C. plutellae and C. carnea responded optimally at 30-35 degrees C and 20-25 degrees C, respectively. These results indicate that the sex pheromone and larval frass volatiles from the diamondback moth, as well as volatile compounds from cabbage, may be used by these natural enemies to locate their diamondback moth host.

Antifungal and antioxidant activities of Coleonema album and C. pulchellum against skin diseases.

PubMed

Fajinmi, Olufunke O; Grúz, Jiří; Tarkowski, Petr; Kulkarni, Manoj G; Finnie, Jeffrey F; Van Staden, Johannes

2017-12-01

Coleonema album (Thunb) Bart. & H. L. Wendl (Rutaceae) has been used in the formulation of skincare products, and the Khoisan people rub it on their skin to add luster. Coleonema pulchellum I. Williams has received less attention in the South African traditional medicine. This study investigates the antifungal and antioxidant activities of C. album and C. pulchellum essential oil (EO) and leaf extracts; and analyzes the chemical components of their EOs. Antifungal activity of leaf extracts was determined using the microdilution method with griseofulvin and ketoconazole as controls. Antifungal capacity of EO was investigated using the 'Volatile release plate method'. Trichophyton rubrum (ATCC 28188) and T. mentagrophytes (ATCC 9533) mycelia (0.3 cm diameter) were placed on fresh yeast malt agar in Petri dishes with filter paper (impregnated with 20 μL of EO) on the lid for direct exposure to EO volatiles while plates without EO were used as controls. The incubation time was seven days. Antioxidant activities of the leaf extracts were determined. Methanol leaf extract of C. pulchellum inhibited the growth of three fungi tested with MIC values of 195, 391 and 49 μg/mL for Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum gypseum, respectively. Terpenes formed the major components of the EO. The EO from both plants inhibited the growth of T. rubrum in vitro. This study revealed the therapeutic value of C. pulchellum. Coleonema album and C. pulchellum should be considered as potential plants for skin ointment from natural origin.

Antibacterial, Antibiofilm Effect of Burdock (Arctium lappa L.) Leaf Fraction and Its Efficiency in Meat Preservation.

PubMed

Lou, Zaixiang; Li, Cheng; Kou, Xingran; Yu, Fuhao; Wang, Hongxin; Smith, Gary M; Zhu, Song

2016-08-01

First, the antibacterial, antibiofilm effect and chemical composition of burdock (Arctium lappa L.) leaf fractions were studied. Then, the efficiency of burdock leaf fractions in pork preservation was evaluated. The results showed that burdock leaf fraction significantly inhibited the growth and biofilm development of Escherichia coli and Salmonella Typhimurium. MICs of burdock leaf fractions on E. coli and Salmonella Typhimurium were both 2 mg/ml. At a concentration of 2.0 mg/ml, the inhibition rates of the fraction on growth and development of E. coli and Salmonella Typhimurium biofilms were 78.7 and 69.9%, respectively. During storage, the log CFU per gram of meat samples treated with burdock leaf fractions decreased 2.15, compared with the samples without treatment. The shelf life of pork treated with burdock leaf fractions was extended 6 days compared with the pork without treatment, and the sensory property was obviously improved. Compared with the control group, burdock leaf fraction treatment significantly decreased the total volatile basic nitrogen value and pH of the meat samples. Chemical composition analysis showed that the burdock leaf fraction consisted of chlorogenic acid, caffeic acid, p-coumaric acid, rutin, cynarin, crocin, luteolin, arctiin, and quercetin. As a vegetable with an abundant source, burdock leaf is safe, affordable, and efficient in meat preservation, indicating that burdock leaf fraction is a promising natural preservative for pork.

An overview of plant volatile metabolomics, sample treatment and reporting considerations with emphasis on mechanical damage and biological control of weeds.

PubMed

Beck, John J; Smith, Lincoln; Baig, Nausheena

2014-01-01

The technology for the collection and analysis of plant-emitted volatiles for understanding chemical cues of plant-plant, plant-insect or plant-microbe interactions has increased over the years. Consequently, the in situ collection, analysis and identification of volatiles are considered integral to elucidation of complex plant communications. Due to the complexity and range of emissions the conditions for consistent emission of volatiles are difficult to standardise. To discuss: evaluation of emitted volatile metabolites as a means of screening potential target- and non-target weeds/plants for insect biological control agents; plant volatile metabolomics to analyse resultant data; importance of considering volatiles from damaged plants; and use of a database for reporting experimental conditions and results. Recent literature relating to plant volatiles and plant volatile metabolomics are summarised to provide a basic understanding of how metabolomics can be applied to the study of plant volatiles. An overview of plant secondary metabolites, plant volatile metabolomics, analysis of plant volatile metabolomics data and the subsequent input into a database, the roles of plant volatiles, volatile emission as a function of treatment, and the application of plant volatile metabolomics to biological control of invasive weeds. It is recommended that in addition to a non-damaged treatment, plants be damaged prior to collecting volatiles to provide the greatest diversity of odours. For the model system provided, optimal volatile emission occurred when the leaf was punctured with a needle. Results stored in a database should include basic environmental conditions or treatments. Copyright © 2013 John Wiley & Sons, Ltd.

Eco-evolutionary factors drive induced plant volatiles: a meta-analysis.

PubMed

Rowen, Elizabeth; Kaplan, Ian

2016-04-01

Herbivore-induced plant volatiles (HIPVs) mediate critical ecological functions, but no studies have quantitatively synthesized data published on HIPVs to evaluate broad patterns. We tested three hypotheses that use eco-evolutionary theory to predict volatile induction: feeding guild (chewing arthropods > sap feeders), diet breadth (specialist herbivores > generalists), and selection history (domesticated plants < wild species). To test these hypotheses, we extracted data from 236 experiments that report volatiles produced by herbivore-damaged and undamaged plants. These data were subjected to meta-analysis, including effects on total volatiles and major biochemical classes. Overall, we found that chewers induced more volatiles than sap feeders, for both total volatiles and most volatile classes (e.g. green leaf volatiles, monoterpenes). Although specialist herbivores induced more total volatiles than generalists, this was inconsistent across chemical classes. Contrary to our expectation, domesticated species induced stronger volatile responses than wild species, even when controlling for plant taxonomy. Surprisingly, this is the first quantitative synthesis of published studies on HIPVs. Our analysis provides support for perceptions in the published literature (chewers > sap feeders), while challenging other commonly held notions (wild > crop). Despite the large number of experiments, we identified several gaps in the existing literature that should guide future investigations. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Taste detection of the non-volatile isothiocyanate moringin results in deterrence to glucosinolate-adapted insect larvae.

PubMed

Müller, Caroline; van Loon, Joop; Ruschioni, Sara; De Nicola, Gina Rosalinda; Olsen, Carl Erik; Iori, Renato; Agerbirk, Niels

2015-10-01

Isothiocyanates (ITCs), released from Brassicales plants after hydrolysis of glucosinolates, are known for their negative effects on herbivores but mechanisms have been elusive. The ITCs are initially present in dissolved form at the site of herbivore feeding, but volatile ITCs may subsequently enter the gas phase and all ITCs may react with matrix components. Deterrence to herbivores resulting from topically applied volatile ITCs in artificial feeding assays may hence lead to ambiguous conclusions. In the present study, the non-volatile ITC moringin (4-(α-L-rhamnopyranosyloxy)benzyl ITC) and its glucosinolate precursor glucomoringin were examined for effects on behaviour and taste physiology of specialist insect herbivores of Brassicales. In feeding bioassays, glucomoringin was not deterrent to larvae of Pieris napi (Lepidoptera: Pieridae) and Athalia rosae (Hymenoptera: Tenthredinidae), which are adapted to glucosinolates. Glucomoringin stimulated feeding of larvae of the related Pieris brassicae (Lepidoptera: Pieridae) and also elicited electrophysiological activity from a glucosinolate-sensitive gustatory neuron in the lateral maxillary taste sensilla. In contrast, the ITC moringin was deterrent to P. napi and P. brassicae at high levels and to A. rosae at both high and low levels when topically applied to cabbage leaf discs (either 12, 120 or 1200 nmol moringin per leaf disc of 1cm diameter). Survival of A. rosae was also significantly reduced when larvae were kept on leaves treated with moringin for several days. Furthermore, moringin elicited electrophysiological activity in a deterrent-sensitive neuron in the medial maxillary taste sensillum of P. brassicae, providing a sensory mechanism for the deterrence and the first known ITC taste response of an insect. In simulated feeding assays, recovery of moringin was high, in accordance with its non-volatile nature. Our results demonstrate taste-mediated deterrence of a non-volatile, natural ITC to glucosinolate-adapted insects. Copyright © 2015 Elsevier Ltd. All rights reserved.

Volatile changes in cv. Verdeal Transmontana olive oil: From the drupe to the table, including storage.

PubMed

Malheiro, Ricardo; Casal, Susana; Rodrigues, Nuno; Renard, Catherine M G C; Pereira, José Alberto

2018-04-01

This study focused on the volatile changes in cv. Verdeal Transmontana throughout the entire olive oil processing chain, from the drupe to olive oil storage up to 12 months, while correlating it with quality parameters and sensory quality. During crushing and malaxation, the volatiles formed were mainly "green-leaf volatiles" (GLVs), namely (E)-2-hexenal, hexanal, and 1-hexanol. Centrifugation and clarification steps increased the total volatile amounts to 130 mg kg -1 . However, clarification also increased nonanal and (E)-2-decenal contents, two markers of oxidation, with a noticeable loss of phenolic compounds and oxidative stability. During storage, the total volatile amounts reduced drastically (94% at 12 months after extraction), together with the positive sensory attributes fruity, green, bitter, and pungent. Despite being classified as extra-virgin after one year of storage, peroxides and conjugated dienes were significantly higher while there was a reduction in antioxidant capacity as well as in phenolic compounds (less 50%) and oxidative stability (57%). The present work allowed concluding that the extraction process modulates the volatile composition of olive oil, with a concentration of volatiles at the clarification step. During storage, volatiles are lost, mainly eight months after extraction, leading to the loss of important sensory attributes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Volatile emissions from Aesculus hippocastanum induced by mining of larval stages of Cameraria ohridella influence oviposition by conspecific females.

PubMed

Johne, A Bettina; Weissbecker, Bernhard; Schütz, Stefan

2006-10-01

Larval stages of the horse chestnut leafminer Cameraria ohridella can completely destroy the surface of horse chestnut leaves, Aesculus hippocastanum. This study investigated the effect of the degree of leaf browning caused by the insect's larvae on olfactory detection, aggregation, and oviposition of C. ohridella adults. The influence of A. hippocastanum flower scent on oviposition of the first generation was also evaluated. Utilizing gas chromatography coupled with parallel detection by mass spectrometry and electroantennography (GC-MS/EAD), more than 30 compounds eliciting responses from antennae of C. ohridella were detected. Oviposition and mining by C. ohridella caused significant changes in the profile of leaf volatiles of A. hippocastanum. After oviposition and subsequent mining by early larval stages (L1-L3), substances such as benzaldehyde, 1,8-cineole, benzyl alcohol, 2-phenylethanol, methyl salicylate, (E)-beta-caryophyllene, and (E,E)-alpha-farnesene were emitted in addition to the compounds emitted by uninfested leaves. Insects were able to detect these compounds. The emitted amount of these substances increased with progressive larval development. During late larval stages (L4, L5) and severe loss of green leaf area, (E,E)-2,4-hexadienal, (E/Z)-linalool oxide (furanoid), nonanal, and decanal were also released by leaves. These alterations of the profile of volatiles caused modifications in aggregation of C. ohridella on leaves. In choice tests, leaves in early infestation stages showed no significant effect on aggregation, whereas insects avoided leaves in late infestation stages. Further choice tests with leaves treated with single compounds led to the identification of substances mediating an increase or decrease in oviposition.

Feeding guild of non-host community members affects host-foraging efficiency of a parasitic wasp.

PubMed

De Rijk, Marjolein; Yang, Daowei; Engel, Bas; Dicke, Marcel; Poelman, Erik H

2016-06-01

Interactions between predator and prey, or parasitoid and host, are shaped by trait- and density-mediated processes involving other community members. Parasitoids that lay their eggs in herbivorous insects locate their hosts through infochemicals such as herbivore-induced plant volatiles (HIPVs) and host-produced kairomones. Hosts are frequently accompanied by non-host herbivores that are unsuitable for the parasitoid. These non-hosts may interfere with host location primarily through trait-mediated processes, by their own infochemicals, and their induction of the emission of plant volatiles. Although it is known that single non-hosts can interfere with parasitoid host location, it is still unknown whether the observed effects are due to species specific characteristics or to the feeding habits of the non-host herbivores. Here we addressed whether the feeding guild of non-host herbivores differentially affects foraging of the parasitoid Cotesia glomerata for its common host, caterpillars of Pieris brassicae feeding on Brassica oleracea plants. We used different phloem-feeding and leaf-chewing non-hosts to study their effects on host location by the parasitoid when searching for host-infested plants based on HIPVs and when searching for hosts on the plant using infochemicals. To evaluate the ultimate effect of these two phases in host location, we studied parasitism efficiency of parasitoids in small plant communities under field-tent conditions. We show that leaf-chewing non-hosts primarily affected host location through trait-mediated effects via plant volatiles, whereas phloem-feeding non-hosts exerted trait-mediated effects by affecting foraging efficiency of the parasitoid on the plant. These trait-mediated effects resulted in associational susceptibility of hosts in environments with phloem feeders and associational resistance in environments with non-host leaf chewers.

Centuries of domestication has not impaired oviposition site-selection function in the silkmoth, Bombyx mori

PubMed Central

Damodaram, Kamala Jayanthi Pagadala; Kempraj, Vivek; Aurade, Ravindra Mahadappa; Rajasekhar, Sowmya Bandhisara; Venkataramanappa, Ravindra Kothapalli; Nandagopal, Bakthavatsalam; Verghese, Abraham

2014-01-01

Oviposition site-selection in insects is mediated through innate recognition templates (IRTs) tuned to specific chemical cues. These cues aid gravid insects in choosing suitable oviposition sites and may even enhance the fitness of their offspring by warding off predators and parasitoids. However, studies on the evolution of oviposition site-selection and cues instigating oviposition in domesticated insects remain elusive. Using the interaction between the silkmoth, Bombyx mori, and its host plant mulberry, Morus alba, as a model system, we demonstrate that centuries of domestication of silkmoth has not impaired its oviposition site-selection function. Silkmoths significantly preferred mulberry leaves to filter paper as oviposition sites. Oviposition assays with filter paper, filter paper treated with leaf volatiles and leaf alone proved that surface texture was not a significant criterion for oviposition site-selection, but volatile cues were. Oviposition assays with electrophysiologically active compounds from mulberry revealed that two of the volatiles, valencene and α-humulene, aided moths in choosing suitable oviposition sites and enhanced egg-laying significantly. Moreover, we show that generalist egg-parasitoids are strongly repelled by valencene and α-humulene. Our results demonstrate that IRTs tuned to cues that aid crucial functions like oviposition site-selection are less likely to be impaired even after centuries of domestication. PMID:25503440

Electrophysiological response and attraction of emerald ash borer to green leaf volatiles (GLVs) emitted by host foliage.

PubMed

de Groot, Peter; Grant, Gary G; Poland, Therese M; Scharbach, Roger; Buchan, Linda; Nott, Reginald W; Macdonald, Linda; Pitt, Doug

2008-09-01

Green leaf volatiles (GLVs) function as host attractants, pheromone synergists, or sexual kairomones for a number of coleopteran folivores. Hence, we focused on host GLVs to determine if they were attractive to adults of the emerald ash borer, Agrilus planipennis (Coleoptera: Buprestidae), which feeds on ash (Fraxinus) foliage. Eight GLVs were identified by chromatography-electroantennogram (GC) and GC-mass spectrometry in foliar headspace volatiles collected in traps containing Super-Q from white ash, Fraxinus americana, and green ash, Fraxinus pennsylvanica, trees. GLVs in the aeration extracts elicited antennal responses from both male and female adults in gas chromatography-electroantennogram detection bioassays. Male antennae were more responsive than female antennae and showed the strongest response to (Z)-3-hexenol. Six field experiments were conducted in Canada and the USA from 2004 to 2006 to evaluate the attractiveness of candidate GLVs, in various lure combinations and dosages. Field experiments demonstrated that lures containing (Z)-3-hexenol were the most effective in increasing trap catch when placed on purple traps in open areas or along the edges of woodlots containing ash. Lures with (Z)-3-hexenol were more attractive to males than females, and dosage may be a factor determining its effectiveness.

Production of methanol from heat-stressed pepper and corn leaf disks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, J.A.

Early Calwonder'' pepper (Capsicum annuum L.) and Jubilee'' corn (Zea mays L.) leaf disks exposed to high temperature stress produced ethylene, ethane, methanol, acetaldehyde, and ethanol based on comparison of retention times during gas chromatography to authentic standards. Methanol, ethanol, and acetaldehyde were also identified by mass spectroscopy. Corn leaf disks produced lower levels of ethylene, ethane, and methanol, but more acetaldehyde and ethanol than pepper. Production of ethane, a by-product of lipid peroxidation, coincided with an increase in electrolyte leakage (EL) in pepper but not in corn. Compared with controls, pepper leaf disks infiltrated with linolenic acid evolved significantlymore » greater amounts of ethane, acetaldehyde, and methanol and similar levels of ethanol. EL and volatile hydrocarbon production were not affected by fatty acid infiltration in corn. Infiltration of pepper leaves with buffers increasing in pH from 5.5 to 9.5 increased methanol production.« less

Chemotaxonomic Study of Citrus, Poncirus and Fortunella Genotypes Based on Peel Oil Volatile Compounds - Deciphering the Genetic Origin of Mangshanyegan (Citrus nobilis Lauriro)

PubMed Central

Liu, Cuihua; Jiang, Dong; Cheng, Yunjiang; Deng, Xiuxin; Chen, Feng; Fang, Liu; Ma, Zhaocheng; Xu, Juan

2013-01-01

Volatile profiles yielded from gas chromatography-mass spectrometry (GC-MS) analysis provide abundant information not only for metabolism-related research, but also for chemotaxonomy. To study the chemotaxonomy of Mangshanyegan, its volatile profiles of fruit and leaf and those of 29 other genotypes of Citrus, Poncirus, and Fortunella were subjected to phylogenetic analyses. Results showed that 145 identified (including 64 tentatively identified) and 15 unidentified volatile compounds were detected from their peel oils. The phylogenetic analysis of peel oils based on hierarchical cluster analysis (HCA) demonstrated a good agreement with the Swingle taxonomy system, in which the three genera of Citrus, Poncirus, and Fortunella were almost completely separated. As to Citrus, HCA indicated that Citrophorum, Cephalocitrus, and Sinocitrus fell into three subgroups, respectively. Also, it revealed that Mangshanyegan contain volatile compounds similar to those from pummelo, though it is genetically believed to be a mandarin. These results were further supported by the principal component analysis of the peel oils and the HCA results of volatile profiles of leaves in the study. PMID:23516475

Down-regulation of SlIAA15 in tomato altered stem xylem development and production of volatile compounds in leaf exudates.

PubMed

Deng, Wei; Yan, Fang; Liu, Minchun; Wang, Xinyu; Li, Zhengguo

2012-08-01

The Aux/IAA family genes encode short-lived nuclear proteins that function as transcriptional regulators in auxin signal transduction. Aux/IAA genes have been reported to control many processes of plant development. Our recent study showed that down-regulation of SlIAA15 in tomato reduced apical dominance, altered pattern of axillary shoot development, increased lateral root formation and leaves thickness. The SlIAA15 suppressed lines display strong reduction of trichome density, suggesting that SlIAA15 is involved in trichome formation. Here, we reported that SlIAA15-suppressed transgenic lines display increased number of xylem cells compared to wild-type plants. Moreover, the monoterpene content in trichome exudates are significantly reduced in SlIAA15 down-regulated leaves. The results provide the roles of SlIAA15 in production of volatile compounds in leaf exudates and xylem development, clearly indicating that members of the Aux/IAA gene family can play distinct and specific functions. 

Photosynthetic photon flux, photoperiod, and temperature effects on emissions of (Z)-3-hexenal, (Z)-3-hexenol, and (Z)-3-hexenyl acetate from lettuce

NASA Technical Reports Server (NTRS)

Charron, C. S.; Cantliffe, D. J.; Wheeler, R. M.; Manukian, A.; Heath, R. R.

1996-01-01

To investigate the effects of environment on plant volatile emissions, 'Waldmann's Green' leaf lettuce was cultivated under different levels of photosynthetic photon flux (PPF), photoperiod, and temperature. A modified growth chamber was used to sample plant volatile emissions nondestructively, over time, and under controlled conditions. Total volatile emission rates were significantly higher from lettuce cultivated under PPF of 360 or 200 micromoles m-2 s-1 compared to 105 micromoles m-2 s-1, and significantly higher under a 16-h photoperiod than an 8-h photoperiod. No differences were detected among emission rates from different temperature treatments. In controlled environments, emissions could be regulated by adjusting environmental conditions accordingly.

Visual-Cerebellar Pathways and Their Roles in the Control of Avian Flight.

PubMed

Wylie, Douglas R; Gutiérrez-Ibáñez, Cristián; Gaede, Andrea H; Altshuler, Douglas L; Iwaniuk, Andrew N

2018-01-01

In this paper, we review the connections and physiology of visual pathways to the cerebellum in birds and consider their role in flight. We emphasize that there are two visual pathways to the cerebellum. One is to the vestibulocerebellum (folia IXcd and X) that originates from two retinal-recipient nuclei that process optic flow: the nucleus of the basal optic root (nBOR) and the pretectal nucleus lentiformis mesencephali (LM). The second is to the oculomotor cerebellum (folia VI-VIII), which receives optic flow information, mainly from LM, but also local visual motion information from the optic tectum, and other visual information from the ventral lateral geniculate nucleus (Glv). The tectum, LM and Glv are all intimately connected with the pontine nuclei, which also project to the oculomotor cerebellum. We believe this rich integration of visual information in the cerebellum is important for analyzing motion parallax that occurs during flight. Finally, we extend upon a suggestion by Ibbotson (2017) that the hypertrophy that is observed in LM in hummingbirds might be due to an increase in the processing demands associated with the pathway to the oculomotor cerebellum as they fly through a cluttered environment while feeding.

Leaf wound induced ultraweak photon emission is suppressed under anoxic stress: Observations of Spathiphyllum under aerobic and anaerobic conditions using novel in vivo methodology.

PubMed

Oros, Carl L; Alves, Fabio

2018-01-01

Plants have evolved a variety of means to energetically sense and respond to abiotic and biotic environmental stress. Two typical photochemical signaling responses involve the emission of volatile organic compounds and light. The emission of certain leaf wound volatiles and light are mutually dependent upon oxygen which is subsequently required for the wound-induced lipoxygenase reactions that trigger the formation of fatty acids and hydroperoxides; ultimately leading to photon emission by chlorophyll molecules. A low noise photomultiplier with sensitivity in the visible spectrum (300-720 nm) is used to continuously measure long duration ultraweak photon emission of dark-adapting whole Spathiphyllum leaves (in vivo). Leaves were mechanically wounded after two hours of dark adaptation in aerobic and anaerobic conditions. It was found that (1) nitrogen incubation did not affect the pre-wound basal photocounts; (2) wound induced leaf biophoton emission was significantly suppressed when under anoxic stress; and (3) the aerobic wound induced emission spectra observed was > 650 nm, implicating chlorophyll as the likely emitter. Limitations of the PMT photocathode's radiant sensitivity, however, prevented accurate analysis from 700-720 nm. Further examination of leaf wounding profile photon counts revealed that the pre-wounding basal state (aerobic and anoxic), the anoxic wounding state, and the post-wounding aerobic state statistics all approximate a Poisson distribution. It is additionally observed that aerobic wounding induces two distinct exponential decay events. These observations contribute to the body of plant wound-induced luminescence research and provide a novel methodology to measure this phenomenon in vivo.

Ecosystem-scale VOC fluxes during an extreme drought in a broad-leaf temperate forest of the Missouri Ozarks (central USA)

EPA Science Inventory

Considerable amounts and varieties of biogenic volatile organic compounds (BVOCs) are exchanged between vegetation and the surrounding air. These BVOCs play key ecological and atmospheric roles that must be adequately represented for accurately modeling the coupled biosphere-atmo...

Volatile-Mediated within-Plant Signaling in Hybrid Aspen: Required for Systemic Responses.

PubMed

Li, Tao; Blande, James D

2017-04-01

Plant volatiles play crucial roles in signaling between plants and their associated community members, but their role in within-plant signaling remains largely unexplored, particularly under field conditions. Using a system comprising the hybrid aspen (Populus tremula x tremuloides) and the specialized herbivorous leaf beetle (Phratora laticollis) and, combining field, greenhouse and laboratory experiments, we examined whether local damage triggered systemic responses in undamaged branches that lack vascular connection to the damaged branches, and to what extent this was caused by airborne volatile signals versus internal signals. An experiment tracing dye through the vasculature of saplings revealed no downward movement of the dye from upper to lower branches, suggesting a lack of vascular connectivity among branches. However, we found under both field and laboratory conditions that herbivore feeding on upper branches elicited volatile emissions by undamaged lower branches. Greenhouse experiments manipulating air contact between damaged and undamaged branches showed that systemic induction of volatiles was almost eliminated when air contact was interrupted. Our findings clearly demonstrate that herbivore-induced volatiles overcome vascular constraints and mediate within-plant signaling. Further, we found that volatile signaling led to induction of different classes of volatiles under field and environment controlled conditions, with a weaker response observed in the field. This difference not only reflects the dose- and time-dependent nature of volatile signaling, but also points out that future studies should focus more on field observations to better understand the ecological role of volatile-mediated within-plant signaling.

Enhancement of Biogas Yield of Poplar Leaf by High-Solid Codigestion with Swine Manure.

PubMed

Wangliang, Li; Zhikai, Zhang; Guangwen, Xu

2016-05-01

The aim of this work was to examine the improvement of anaerobic biodegradability of organic fractions of poplar leaf from codigestion with swine manure (SM), thus biogas yield and energy recovery. When poplar leaf was used as a sole substrate, the cumulative biogas yield was low, about 163 mL (g volatile solid (VS))(-1) after 45 days of digestion with a substrate/inoculum ratio of 2.5 and a total solid (TS) of 22 %. Under the same condition, the cumulative biogas yield of poplar leaf reached 321 mL (g VS)(-1) when SM/poplar leaf ratio was 2:5 (based on VS). The SM/poplar leaf ratio can determine C/N ratio of the cosubstrate and thus has significant influence on biogas yield. When the SM/poplar leaf ratio was 2:5, C/N ratio was calculated to be 27.02, and the biogas yield in 45 days of digestion was the highest. The semi-continuous digestion of poplar leaf was carried out with the organic loading rate of 1.25 and 1.88 g VS day(-1). The average daily biogas yield was 230.2 mL (g VS)(-1) and 208.4 mL (g VS)(-1). The composition analysis revealed that cellulose and hemicellulose contributed to the biogas production.

Green leaf volatiles: biosynthesis, biological functions and their applications in biotechnology.

PubMed

ul Hassan, Muhammad Naeem; Zainal, Zamri; Ismail, Ismanizan

2015-08-01

Plants have evolved numerous constitutive and inducible defence mechanisms to cope with biotic and abiotic stresses. These stresses induce the expression of various genes to activate defence-related pathways that result in the release of defence chemicals. One of these defence mechanisms is the oxylipin pathway, which produces jasmonates, divinylethers and green leaf volatiles (GLVs) through the peroxidation of polyunsaturated fatty acids (PUFAs). GLVs have recently emerged as key players in plant defence, plant-plant interactions and plant-insect interactions. Some GLVs inhibit the growth and propagation of plant pathogens, including bacteria, viruses and fungi. In certain cases, GLVs released from plants under herbivore attack can serve as aerial messengers to neighbouring plants and to attract parasitic or parasitoid enemies of the herbivores. The plants that perceive these volatile signals are primed and can then adapt in preparation for the upcoming challenges. Due to their 'green note' odour, GLVs impart aromas and flavours to many natural foods, such as vegetables and fruits, and therefore, they can be exploited in industrial biotechnology. The aim of this study was to review the progress and recent developments in research on the oxylipin pathway, with a specific focus on the biosynthesis and biological functions of GLVs and their applications in industrial biotechnology. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Volatiles and Nonvolatiles in Flourensia campestris Griseb. (Asteraceae), How Much Do Capitate Glandular Trichomes Matter?

PubMed

Piazza, Leonardo A; López, Daniela; Silva, Mariana P; López Rivilli, Marisa J; Tourn, Mónica G; Cantero, Juan J; Scopel, Ana L

2018-03-01

The distribution and ultrastructure of capitate glandular trichomes (GTs) in Flourensia species (Asteraceae) have been recently elucidated, but their metabolic activity and potential biological function remain unexplored. Selective nonvolatile metabolites from isolated GTs were strikingly similar to those found on leaf surfaces. The phytotoxic allelochemical sesquiterpene (-)-hamanasic acid A ((-)-HAA) was the major constituent (ca. 40%) in GTs. Although GTs are quaternary ammonium compounds (QACs)-accumulating species, glycine betaine was not found in GTs; it was only present in the leaf mesophyll. Two (-)-HAA accompanying surface secreted products: compounds 4-hydroxyacetophenone (piceol; 1) and 2-hydroxy-5-methoxyacetophenone (2), which were isolated and fully characterized (GC/MS, NMR), were present in the volatiles found in GTs. The essential oils of fresh leaves revealed ca. 33% monoterpenes, 26% hydrocarbon- and 30% oxygenated sesquiterpenes, most of them related to cadinene and bisabolene derivatives. Present results suggest a main role of GTs in determining the volatile and nonvolatile composition of F. campestris leaves. Based on the known activities of the compounds identified, it can be suggested that GTs in F. campestris would play key ecological functions in plant-pathogen and plant-plant interactions. In addition, the strikingly high contribution of compounds derived from cadinene and bisabolene pathways, highlights the potential of this species as a source of high-valued bioproducts. © 2018 Wiley-VHCA AG, Zurich, Switzerland.

Biological relevance of volatile organic compounds emitted during the pathogenic interactions between apple plants and Erwinia amylovora.

PubMed

Cellini, Antonio; Buriani, Giampaolo; Rocchi, Lorenzo; Rondelli, Elena; Savioli, Stefano; Rodriguez Estrada, Maria T; Cristescu, Simona M; Costa, Guglielmo; Spinelli, Francesco

2018-01-01

Volatile organic compounds emitted during the infection of apple (Malus pumila var. domestica) plants by Erwinia amylovora or Pseudomonas syringae pv. syringae were studied by gas chromatography-mass spectrometry and proton transfer reaction-mass spectrometry, and used to treat uninfected plants. Infected plants showed a disease-specific emission of volatile organic compounds, including several bio-active compounds, such as hexenal isomers and 2,3-butanediol. Leaf growth promotion and a higher resistance to the pathogen, expressed as a lower bacterial growth and migration in plant tissues, were detected in plants exposed to volatile compounds from E. amylovora-infected plants. Transcriptional analysis revealed the activation of salicylic acid synthesis and signal transduction in healthy plants exposed to volatiles produced by E. amylovora-infected neighbour plants. In contrast, in the same plants, salicylic acid-dependent responses were repressed after infection, whereas oxylipin metabolism was activated. These results clarify some metabolic and ecological aspects of the pathogenic adaptation of E. amylovora to its host. © 2016 BSPP AND JOHN WILEY & SONS LTD.

Identification and field evaluation of attractants for the cranberry weevil, Anthonomus musculus Say.

PubMed

Szendrei, Zsofia; Averill, Anne; Alborn, Hans; Rodriguez-Saona, Cesar

2011-04-01

Studies were conducted to develop an attractant for the cranberry weevil, Anthonomus musculus, a pest of blueberry and cranberry flower buds and flowers in the northeastern United States. In previous studies, we showed that cinnamyl alcohol, the most abundant blueberry floral volatile, and the green leaf volatiles (Z)-3-hexenyl acetate and hexyl acetate, emitted from both flowers and flower buds, elicit strong antennal responses from A. musculus. Here, we found that cinnamyl alcohol did not increase capture of A. musculus adults on yellow sticky traps compared with unbaited controls; however, weevils were highly attracted to traps baited with the Anthonomus eugenii Cano aggregation pheromone, indicating that these congeners share common pheromone components. To identify the A. musculus aggregation pheromone, headspace volatiles were collected from adults feeding on blueberry or cranberry flower buds and analyzed by gas chromatography-mass spectrometry. Three male-specific compounds were identified: (Z)-2-(3,3-dimethyl-cyclohexylidene) ethanol (Z grandlure II); (Z)-(3,3-dimethylcyclohexylidene) acetaldehyde (grandlure III); and (E)-(3,3- dimethylcyclohexylidene) acetaldehyde (grandlure IV). A fourth component, (E)-3,7-dimethyl-2,6-octadien-1-ol (geraniol), was emitted in similar quantities by males and females. The emission rates of these volatiles were about 2.8, 1.8, 1.3, and 0.9 ng/adult/d, respectively. Field experiments in highbush blueberry (New Jersey) and cranberry (Massachusetts) examined the attraction of A. musculus to traps baited with the male-produced compounds and geraniol presented alone and combined with (Z)-3-hexenyl acetate and hexyl acetate, and to traps baited with the pheromones of A. eugenii and A. grandis. In both states and crops, traps baited with the A. musculus male-produced compounds attracted the highest number of adults. Addition of the green leaf volatiles did not affect A. musculus attraction to its pheromone but skewed the sex ratio of the captured adults towards females. Although the role of plant volatiles in host-plant location by A. musculus is still unclear, our studies provide the first identification of the primary A. musculus aggregation pheromone components that can be used to monitor this pest in blueberry and cranberry pest management programs.

Metabolically speaking: Possible reasons behind the tolerance of 'Sugar Belle' mandarin hybrid to huanglongbing.

PubMed

Killiny, Nabil; Valim, Maria Filomena; Jones, Shelley E; Omar, Ahmad A; Hijaz, Faraj; Gmitter, Fred G; Grosser, Jude W

2017-07-01

Huanglongbing (HLB) is currently considered the most destructive disease of citrus. Since its spread to the Americas, HLB has killed millions of trees and caused a sharp decline in production in many citrus growing regions. With the continuous spread of HLB disease in Florida and worldwide, there is an urgent need for the development of commercial citrus cultivars with a strong tolerance to HLB. Interestingly, field observations showed that some of the recently released mandarin hybrids such as 'Sugar Belle' were tolerant to HLB. In this study, we investigated the volatile and non-volatile metabolites of greenhouse-grown 'Sugar Belle' mandarin and four of its ancestors in order to understand why 'Sugar Belle' mandarin is relatively tolerant to HLB. Leaf volatiles were directly extracted with hexane and analyzed using gas chromatography-mass spectrometry (GC-MS). Leaf polar metabolites were extracted with a mixture of methanol:water (1:1, v/v), derivatized to their trimethylsilyl ethers, and analyzed using GC-MS. Forty-seven volatile compounds and forty-two polar metabolites were detected in 'Sugar Belle' mandarin leaves and its ancestors. 'Sugar Belle' was high in several volatiles such as α-thujene, para-cymene, γ-terpinene, thymol, β-elemene, and (E)-β-caryophyllene. Some of these volatiles, especially thymol, β-elemene, and (E)-β-caryophyllene are known for their anti-microbial activity. In addition, 'Sugar Belle' mandarin was the highest in synephrine, benzoic acid, ferulic acid, caffeic acid, chiro-inositol, fructose, glucose, threonic acid, saccharic acid, and galactaric acid, and the second in threonine, malic acid, and myo-inositol compared to the ancestors. Phenolic compounds such as benzoic, ferulic, and caffeic acids may act as antibacterial agents, whereas others like sugar alcohols may protect 'Sugar Belle' mandarin from stress during pathogen attack. The tolerance of 'Sugar Belle' and other newly released mandarin hybrids should be further evaluated using greenhouse controlled studies. If tolerance of these hybrids is confirmed, they could be used to replace the traditionally susceptible cultivars. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Attraction of Diabrotica barberi Smith and Lawrence (Coleoptera: Chrysomelidae) to eugenol-baited traps in soybean

USDA-ARS?s Scientific Manuscript database

Diabrotica barberi Smith and Lawrence (the northern corn rootworm) is a native North American leaf beetle and a major pest of corn. However, adult D. barberi forage in various habitats outside of corn, including soybean, roadside vegetation, and prairie. Eugenol is a common floral volatile that ha...

A specialist root herbivore reduces plant resistance and uses an induced plant volatile to aggregate in a density dependent manner

USDA-ARS?s Scientific Manuscript database

1. Leaf-herbivore attack often triggers induced resistance in plants. However, certain specialist herbivores can also take advantage of the induced metabolic changes. In some cases, they even manipulate plant resistance, leading to a phenomenon called induced susceptibility. Compared to above-ground...

Herbivory by the insect diaphorina citri induces greater change in citrus plant volatile profile than does infection by the bacterium, Candidatus Liberibacter asiaticus

PubMed Central

Hijaz, Faraj; El-Shesheny, Ibrahim; Killiny, Nabil

2013-01-01

The volatile organic compound (VOC) profile in plant leaves often changes after biotic and abiotic stresses. Monitoring changes in VOCs in plant leaves could provide valuable information about multitrophic interactions. In the current study, we investigated the effect of Asian citrus psyllid (ACP) infestation, citrus greening pathogen (Candidatus Liberibacter asiaticus [CLas]) infection, and simultaneous attack by ACP and CLas on the VOC content of citrus leaves. Leaf volatiles were extracted using hexane and analyzed with gas chromatography-mass spectrometry (GC-MS). Although ACP is a phloem-sucking insect that causes minimal damage to plant tissues, the relative amount of 21 out of the 27 VOCs increased 2- to 10-fold in ACP-infested plants. The relative amount of d-limonene, β-phelandrene, citronellal, and undecanal were increased 4- to 20- fold in CLas-infected plants. A principle component analysis (PCA) and cluster analysis (CA) showed that VOC patterns of ACP-infested and CLas-infected plants were different from each other and were also different from the controls, while the VOC pattern of double-attacked plants was more like that of the controls than that of ACP-infested or CLas-infected plants. VOC amounts from leaves were compromised when plants were attacked by ACP and CLas. The results of this study showed that a simple direct extraction of citrus leaf volatiles could be successfully used to discriminate between healthy and CLas-infected plants. Information about the effects of insect and pathogen attack on the VOC content profile of plants might contribute to a better understanding of biotic stress. PMID:23857364

Herbivory by the insect diaphorina citri induces greater change in citrus plant volatile profile than does infection by the bacterium, Candidatus Liberibacter asiaticus.

PubMed

Hijaz, Faraj; El-Shesheny, Ibrahim; Killiny, Nabil

2013-10-01

The volatile organic compound (VOC) profile in plant leaves often changes after biotic and abiotic stresses. Monitoring changes in VOCs in plant leaves could provide valuable information about multitrophic interactions. In the current study, we investigated the effect of Asian citrus psyllid (ACP) infestation, citrus greening pathogen (Candidatus Liberibacter asiaticus [CLas]) infection, and simultaneous attack by ACP and CLas on the VOC content of citrus leaves. Leaf volatiles were extracted using hexane and analyzed with gas chromatography-mass spectrometry (GC-MS). Although ACP is a phloem-sucking insect that causes minimal damage to plant tissues, the relative amount of 21 out of the 27 VOCs increased 2- to 10-fold in ACP-infested plants. The relative amount of d-limonene, β-phelandrene, citronellal, and undecanal were increased 4- to 20- fold in CLas-infected plants. A principle component analysis (PCA) and cluster analysis (CA) showed that VOC patterns of ACP-infested and CLas-infected plants were different from each other and were also different from the controls, while the VOC pattern of double-attacked plants was more like that of the controls than that of ACP-infested or CLas-infected plants. VOC amounts from leaves were compromised when plants were attacked by ACP and CLas. The results of this study showed that a simple direct extraction of citrus leaf volatiles could be successfully used to discriminate between healthy and CLas-infected plants. Information about the effects of insect and pathogen attack on the VOC content profile of plants might contribute to a better understanding of biotic stress.

Herbivore-induced maize leaf volatiles affect attraction and feeding behavior of Spodoptera littoralis caterpillars

PubMed Central

von Mérey, Georg E.; Veyrat, Nathalie; D'Alessandro, Marco; Turlings, Ted C. J.

2013-01-01

Plants under herbivore attack emit volatile organic compounds (VOCs) that can serve as foraging cues for natural enemies. Adult females of Lepidoptera, when foraging for host plants to deposit eggs, are commonly repelled by herbivore-induced VOCs, probably to avoid competition and natural enemies. Their larval stages, on the other hand, have been shown to be attracted to inducible VOCs. We speculate that this contradicting behavior of lepidopteran larvae is due to a need to quickly find a new suitable host plant if they have fallen to the ground. However, once they are on a plant they might avoid the sites with fresh damage to limit competition and risk of cannibalism by conspecifics, as well as exposure to natural enemies. To test this we studied the effect of herbivore-induced VOCs on the attraction of larvae of the moth Spodoptera littoralis and on their feeding behavior. The experiments further considered the importance of previous feeding experience on the responses of the larvae. It was confirmed that herbivore-induced VOCs emitted by maize plants are attractive to the larvae, but exposure to the volatiles decreased the growth rate of caterpillars at early developmental stages. Larvae that had fed on maize previously were more attracted by VOCs of induced maize than larvae that had fed on artificial diet. At relatively high concentrations synthetic green leaf volatiles, indicative of fresh damage, also negatively affected the growth rate of caterpillars, but not at low concentrations. In all cases, feeding by the later stages of the larvae was not affected by the VOCs. The results are discussed in the context of larval foraging behavior under natural conditions, where there may be a trade-off between using available host plant signals and avoiding competitors and natural enemies. PMID:23825475

GC-MS analysis of volatile compounds of Perilla frutescens Britton var. Japonica accessions: Morphological and seasonal variability.

PubMed

Ghimire, Bimal Kumar; Yoo, Ji Hye; Yu, Chang Yeon; Chung, Ill-Min

2017-07-01

To investigate the composition of volatile compounds in the different accessions of Perilla frutescens (P. frutescens) collected from various habitats of China and Japan. In the present study, the essential oil from the leaves of P. frutescens cultivars from China and Japan was extracted by hydro-distillation and the chemical composition and concentration of the volatile components present in the oils were determined by gas chromatography-mass spectrometry (GC-MS) analysis. Among the volatile components, the major proportion was of perilla ketone, which was followed by elemicin and beta-caryophyllene in the Chinese Perilla cultivars. The main component in the oil extracted from the Japanese accessions was myristicin, which was followed by perilla ketone and beta-caryophyllene. We could distinguish seven chemotypes, namely the perilla ketone (PK) type, perilla ketone, myristicin (PM) type, perilla ketone, unknown (PU) type, perilla ketone, beta-caryophyllene, myristicine (PB) type, perilla ketone, myristicin, unknown (PMU) type, perilla ketone, elemicine, myristicin, beta-caryophyllene (PEMB) type, and the perilla ketone, limonene, beta-cryophyllene, myristicin (L) type. Most of the accessions possessed higher essential oil content before the flowering time than at the flowering stage. The average plant height, leaf length, leaf width of the Chinese accessions was higher than those of the Japanese accessions. The results revealed that the harvest time and geographical origin caused polymorphisms in the essential oil composition and morphological traits in the Perilla accessions originating from China and Japan. Therefore, these chemotypes with desirable characters might be useful for industrial exploitation and for determining the harvest time. Copyright © 2017 Hainan Medical University. Production and hosting by Elsevier B.V. All rights reserved.

Plant leaf traits, canopy processes, and global atmospheric chemistry interactions.

NASA Astrophysics Data System (ADS)

Guenther, A. B.

2017-12-01

Plants produce and emit a diverse array of volatile metabolites into the atmosphere that participate in chemical reactions that influence distributions of air pollutants and short-lived climate forcers including organic aerosol, ozone and methane. It is now widely accepted that accurate estimates of these emissions are required as inputs for regional air quality and global climate models. Predicting these emissions is complicated by the large number of volatile organic compounds, driving variables (e.g., temperature, solar radiation, abiotic and biotic stresses) and processes operating across a range of scales. Modeling efforts to characterize emission magnitude and variations will be described along with an assessment of the observations available for parameterizing and evaluating these models including discussion of the limitations and challenges associated with existing model approaches. A new approach for simulating canopy scale organic emissions on regional to global scales will be described and compared with leaf, canopy and regional scale flux measurements. The importance of including additional compounds and processes as well as improving estimates of existing ones will also be discussed.

Effect of grape bunch sunlight exposure and UV radiation on phenolics and volatile composition of Vitis vinifera L. cv. Pinot noir wine.

PubMed

Song, Jianqiang; Smart, Richard; Wang, Hua; Dambergs, Bob; Sparrow, Angela; Qian, Michael C

2015-04-15

The effect of canopy leaf removal and ultraviolet (UV) on Pinot noir grape and wine composition was investigated in this study. Limited basal leaf removal in the fruit zone was conducted, compared to shaded bunches. The UV exposure was controlled using polycarbonate screens to block UV radiation, and acrylic screens to pass the UV. The results showed that bunch sunlight and UV exposure significantly increased the Brix and pH in the grape juice, and increased substantially wine colour density, anthocyanins, total pigment, total phenolics and tannin content. Bunch sunlight and UV exposure affected terpene alcohols, C13-norisprenoids and other volatile composition of the wine differently. Sunlight exposure and UV resulted in increase of nerol, geraniol and citronellol but not linalool. Sunlight exposure slightly increased the concentration of β-ionone, but the increase was not statistically significant for UV treatment. Neither sunlight nor UV treatment showed any impact on the concentration of β-damascenone. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Novel System for Simultaneous or Sequential Integration of Multiple Gene-Loading Vectors into a Defined Site of a Human Artificial Chromosome

PubMed Central

Suzuki, Teruhiko; Kazuki, Yasuhiro; Oshimura, Mitsuo; Hara, Takahiko

2014-01-01

Human artificial chromosomes (HACs) are gene-delivery vectors suitable for introducing large DNA fragments into mammalian cells. Although a HAC theoretically incorporates multiple gene expression cassettes of unlimited DNA size, its application has been limited because the conventional gene-loading system accepts only one gene-loading vector (GLV) into a HAC. We report a novel method for the simultaneous or sequential integration of multiple GLVs into a HAC vector (designated as the SIM system) via combined usage of Cre, FLP, Bxb1, and φC31 recombinase/integrase. As a proof of principle, we first attempted simultaneous integration of three GLVs encoding EGFP, Venus, and TdTomato into a gene-loading site of a HAC in CHO cells. These cells successfully expressed all three fluorescent proteins. Furthermore, microcell-mediated transfer of HACs enabled the expression of those fluorescent proteins in recipient cells. We next demonstrated that GLVs could be introduced into a HAC one-by-one via reciprocal usage of recombinase/integrase. Lastly, we introduced a fourth GLV into a HAC after simultaneous integration of three GLVs by FLP-mediated DNA recombination. The SIM system expands the applicability of HAC vectors and is useful for various biomedical studies, including cell reprogramming. PMID:25303219

A novel system for simultaneous or sequential integration of multiple gene-loading vectors into a defined site of a human artificial chromosome.

PubMed

Suzuki, Teruhiko; Kazuki, Yasuhiro; Oshimura, Mitsuo; Hara, Takahiko

2014-01-01

Human artificial chromosomes (HACs) are gene-delivery vectors suitable for introducing large DNA fragments into mammalian cells. Although a HAC theoretically incorporates multiple gene expression cassettes of unlimited DNA size, its application has been limited because the conventional gene-loading system accepts only one gene-loading vector (GLV) into a HAC. We report a novel method for the simultaneous or sequential integration of multiple GLVs into a HAC vector (designated as the SIM system) via combined usage of Cre, FLP, Bxb1, and φC31 recombinase/integrase. As a proof of principle, we first attempted simultaneous integration of three GLVs encoding EGFP, Venus, and TdTomato into a gene-loading site of a HAC in CHO cells. These cells successfully expressed all three fluorescent proteins. Furthermore, microcell-mediated transfer of HACs enabled the expression of those fluorescent proteins in recipient cells. We next demonstrated that GLVs could be introduced into a HAC one-by-one via reciprocal usage of recombinase/integrase. Lastly, we introduced a fourth GLV into a HAC after simultaneous integration of three GLVs by FLP-mediated DNA recombination. The SIM system expands the applicability of HAC vectors and is useful for various biomedical studies, including cell reprogramming.

Leaf level emissions of volatile organic compounds (VOC) from some Amazonian and Mediterranean plants

NASA Astrophysics Data System (ADS)

Bracho-Nunez, A.; Knothe, , N. M.; Welter, S.; Staudt, M.; Costa, W. R.; Liberato, M. A. R.; Piedade, M. T. F.; Kesselmeier, J.

2013-09-01

Emission inventories defining regional and global biogenic volatile organic compounds (VOC) emission strengths are needed to determine the impact of VOC on atmospheric chemistry (oxidative capacity) and physics (secondary organic aerosol formation and effects). The aim of this work was to contribute with measurements of tree species from the poorly described tropical vegetation in direct comparison with the quite well-investigated, highly heterogeneous emissions from Mediterranean vegetation. VOC emission from sixteen plant species from the Mediterranean area were compared with twelve plant species from different environments of the Amazon basin by an emission screening at leaf level using branch enclosures. Analysis of the volatile organics was performed online by a proton-transfer-reaction mass spectrometer (PTR-MS) and offline by collection on adsorbent tubes and subsequent gas chromatographic analysis. Isoprene was the most dominant compound emitted followed by monoterpenes, methanol and acetone. The average loss rates of VOC carbon in relation to the net CO2 assimilation were found below 4% and indicating normal unstressed plant behavior. Most of the Mediterranean species emitted a large variety of monoterpenes, whereas only five tropical species were identified as monoterpene emitters exhibiting a quite conservative emission pattern (α-pinene < limonene < sabinene < ß-pinene). Mediterranean plants showed additional emissions of sesquiterpenes. In the case of Amazonian plants no sesquiterpenes were detected. However, missing of sesquiterpenes may also be due to a lack of sensitivity of the measuring systems. Furthermore, our screening activities cover only 1% of tree species of such tropical areas as estimated based on recent biodiversity reports. Methanol emissions, an indicator of growth, were found to be common in most of the tropical and Mediterranean species. A few species from both ecosystems showed acetone emissions. The observed heterogeneous emissions, including reactive VOC species which are not easily detected by flux measurements, give reason to perform more screening at leaf level and, whenever possible, within the forests under ambient conditions.

The influence of apical and basal defoliation on the canopy structure and biochemical composition of Vitis vinifera cv. Shiraz grapes and wine

NASA Astrophysics Data System (ADS)

Zhang, Pangzhen; Wu, Xiwen; Needs, Sonja; Liu, Di; Fuentes, Sigfredo; Howell, Kate

2017-07-01

Defoliation is a commonly used viticultural technique to balance the ratio between grapevine vegetation and fruit. Defoliation is conducted around the fruit zone to reduce the leaf photosynthetic area, and to increase sunlight exposure of grape bunches. Apical leaf removal is not commonly practiced, and therefore its influence on canopy structure and resultant wine aroma is not well studied. This study quantified the influences of apical and basal defoliation on canopy structure parameters using canopy cover photography and computer vision algorithms. The influence of canopy structure changes on the chemical compositions of grapes and wines was investigated over two vintages (2010-11 and 2015-16) in Yarra Valley, Australia. The Shiraz grapevines were subjected to five different treatments: no leaf removal (Ctrl); basal (TB) and apical (TD) leaf removal at veraison and intermediate ripeness, respectively. Basal leaf removal significantly reduced the leaf area index and foliage cover and increased canopy porosity, while apical leaf removal had limited influences on canopy parameters. However, the latter tended to result in lower alcohol level in the finished wine. Statistically significant increases in pH and decreases in TA was observed in shaded grapes, while no significant changes in the color profile and volatile compounds of the resultant wine were found. These results suggest that apical leaf removal is an effective method to reduce wine alcohol concentration with minimal influences on wine composition.

Expanded separation technique for chlorophyll metabolites in Oriental tobacco leaf using non aqueous reversed phase chromatography.

PubMed

Ishida, Naoyuki

2011-08-26

An improved separation method for chlorophyll metabolites in Oriental tobacco leaf was developed. While Oriental leaf still gives the green color even after the curing process, little attention has been paid to the detailed composition of the remaining green pigments. This study aimed to identify the green pigments using non aqueous reversed phase chromatography (NARPC). To this end, liquid chromatograph (LC) equipped with a photo diode array detector (DAD) and an atmospheric pressure chemical ionization/mass spectrometer (APCI/MSD) was selected, because it is useful for detecting low polar non-volatile compounds giving green color such as pheophytin a. Identification was based on the wavelength spectrum, mass spectrum and retention time, comparing the analytes in Oriental leaf with the commercially available and synthesized components. Consequently, several chlorophyll metabolites such as hydroxypheophytin a, solanesyl pheophorbide a and solanesyl hydroxypheophorbide a were newly identified, in addition to typical green pigments such as chlorophyll a and pheophytin a. Chlorophyll metabolites bound to solanesol were considered the tobacco specific components. NARPC expanded the number of detectable low polar chlorophyll metabolites in Oriental tobacco leaf. Copyright © 2011 Elsevier B.V. All rights reserved.

Sulfur volatiles from Allium spp. affect Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), response to citrus volatiles.

PubMed

Mann, R S; Rouseff, R L; Smoot, J M; Castle, W S; Stelinski, L L

2011-02-01

The Asian citrus psyllid, Diaphorina citri Kuwayama, vectors Candidatus Liberibacter asiaticus (Las) and Candidatus Liberibacter americanus (Lam), the presumed causal agents of huanglongbing. D. citri generally rely on olfaction and vision for detection of host cues. Plant volatiles from Allium spp. (Alliaceae) are known to repel several arthropod species. We examined the effect of garlic chive (A. tuberosum Rottl.) and wild onion (A. canadense L.) volatiles on D. citri behaviour in a two-port divided T-olfactometer. Citrus leaf volatiles attracted significantly more D. citri adults than clean air. Volatiles from crushed garlic chive leaves, garlic chive essential oil, garlic chive plants, wild onion plants and crushed wild onion leaves all repelled D. citri adults when compared with clean air, with the first two being significantly more repellent than the others. However, when tested with citrus volatiles, only crushed garlic chive leaves and garlic chive essential oil were repellent, and crushed wild onions leaves were not. Analysis of the headspace components of crushed garlic chive leaves and garlic chive essential oil by gas chromatography-mass spectrometry revealed that monosulfides, disulfides and trisulfides were the primary sulfur volatiles present. In general, trisulfides (dimethyl trisulfide) inhibited the response of D. citri to citrus volatiles more than disulfides (dimethyl disulfide, allyl methyl disulfide, allyl disulfide). Monosulfides did not affect the behaviour of D. citri adults. A blend of dimethyl trisulfide and dimethyl disulfide in 1:1 ratio showed an additive effect on inhibition of D. citri response to citrus volatiles. The plant volatiles from Allium spp. did not affect the behaviour of the D. citri ecto-parasitoid Tamarixia radiata (Waterston). Thus, Allium spp. or the tri- and di-sulphides could be integrated into management programmes for D. citri without affecting natural enemies.

Developing kairomone-based lures and traps targeting female Spilonota ocellana (Lepidoptera: Tortricidae) in apple orchards treated with ex pheromones

USDA-ARS?s Scientific Manuscript database

Spilonota ocellana (Denis and Schiffermüller) can be a serious pest of organic apples in British Columbia. Recent discovery that S. ocellana moths are attracted by a lure combining acetic acid (AA) and benzyl nitrile (BN), a caterpillar-induced apple leaf volatile, provides an opportunity to develo...

Enhanced attraction of Plutella xylostella (Lepidoptera: Plutellidae) to pheromone-baited traps with the addition of green leaf volatiles

USDA-ARS?s Scientific Manuscript database

The GLVs, such as 1-hexanol and (Z)-3-hexen-1-ol, elicited strong electroantennographic responses from unmated male and female P. xylostella, whereas (Z)-3-hexenyl acetate only produced a relative weak response. The behavioral responses of unmated moths to GLVs were further tested in Y-tube olfactom...

Gall volatiles defend aphids against a browsing mammal

PubMed Central

2013-01-01

Background Plants have evolved an astonishing array of survival strategies. To defend against insects, for example, damaged plants emit volatile organic compounds that attract the herbivore’s natural enemies. So far, plant volatile responses have been studied extensively in conjunction with leaf chewing and sap sucking insects, yet little is known about the relationship between plant volatiles and gall-inducers, the most sophisticated herbivores. Here we describe a new role for volatiles as gall-insects were found to benefit from this plant defence. Results Chemical analyses of galls triggered by the gregarious aphid Slavum wertheimae on wild pistachio trees showed that these structures contained and emitted considerably higher quantities of plant terpenes than neighbouring leaves and fruits. Behavioural assays using goats as a generalist herbivore confirmed that the accumulated terpenes acted as olfactory signals and feeding deterrents, thus enabling the gall-inducers to escape from inadvertent predation by mammals. Conclusions Increased emission of plant volatiles in response to insect activity is commonly looked upon as a “cry for help” by the plant to attract the insect’s natural enemies. In contrast, we show that such volatiles can serve as a first line of insect defences that extends the ‘extended phenotype’ represented by galls, beyond physical boundaries. Our data support the Enemy hypothesis insofar that high levels of gall secondary metabolites confer protection against natural enemies. PMID:24020365

Use of olive leaf extract to reduce lipid oxidation of baked snacks.

PubMed

Difonzo, Graziana; Pasqualone, Antonella; Silletti, Roccangelo; Cosmai, Lucrezia; Summo, Carmine; Paradiso, Vito M; Caponio, Francesco

2018-06-01

Olive leaves are a waste of the olive oil processing industry and represent a good source of phenolic compounds. The aim of this work was to assess the influence of olive leaf extract (OLE) on lipid oxidation of baked snacks, like breadsticks, made with wheat flour, extra virgin olive oil (EVO), white wine, and salt. Two EVOs having different peroxide value and antioxidant profile (total phenol content, tocopherols, carotenoids, and antioxidant activity) were considered. The snacks were subjected to oven test or stored in the usual conditions of retailer shelves. The obtained data highlighted that EVO plays a key role both for the quality and for the shelf-life of baked snacks and the use of OLE is recommended especially when baked snacks are produced with low quality EVO which therefore does not have a good content of natural antioxidants. The OLE addition significantly reduced the forced oxidative degradation during oven test, as evidenced by a decrease of 27% in oxidation-related volatile compounds and of 42% in triacylglycerol oligopolymers compared to control snacks (CTR) without OLE. Moreover, OLE effectively acted also in normal storage conditions, improving sensory data, induction times, antioxidant activity, and volatile compounds compared to CTR (i.e. hexanal 165.49 vs 38.31 μg g -1 in OLE-added). The amount of oxidation-related volatile compounds showed an opposite trend with the quality level of oil used. Copyright © 2018 Elsevier Ltd. All rights reserved.

Impact of heat stress on the emissions of monoterpenes, sesquiterpenes, phenolic BVOC and green leaf volatiles from several tree species

NASA Astrophysics Data System (ADS)

Kleist, E.; Mentel, T. F.; Andres, S.; Bohne, A.; Folkers, A.; Kiendler-Scharr, A.; Rudich, Y.; Springer, M.; Tillmann, R.; Wildt, J.

2012-07-01

Changes in the biogenic volatile organic compound (BVOC) emissions from European beech, Palestine oak, Scots pine, and Norway spruce exposed to heat stress were measured in a laboratory setup. In general, heat stress decreased the de novo emissions of monoterpenes, sesquiterpenes and phenolic BVOC. Decreasing emission strength with heat stress was independent of the tree species and whether the de novo emissions being constitutive or induced by biotic stress. In contrast, heat stress induced emissions of green leaf volatiles. It also amplified the release of monoterpenes stored in resin ducts of conifers probably due to heat-induced damage of these resin ducts. The increased release of monoterpenes could be strong and long lasting. But, despite of such strong monoterpene emission pulses, the net effect of heat stress on BVOC emissions from conifers can be an overall decrease. In particular during insect attack on conifers the plants showed de novo emissions of sesquiterpenes and phenolic BVOC which exceeded constitutive monoterpene emissions from pools. The heat stress induced decrease of these de novo emissions was larger than the increased release caused by damage of resin ducts. We project that global change induced heat waves may cause increased BVOC emissions only in cases where the respective areas are predominantly covered with conifers that do not emit high amounts of sesquiterpenes and phenolic BVOC. Otherwise the overall effect of heat stress will be a decrease in BVOC emissions.

Reactive trace gas emissions from stressed plants: a poorly characterized major source of atmospheric volatiles

NASA Astrophysics Data System (ADS)

Niinemets, Ülo

2017-04-01

Vegetation constitutes the greatest source of reactive volatile organic compounds in the atmosphere. The current emission estimates primarily rely on constitutive emissions that are present only in some plant species. However, all plant species can be induced to emit reactive volatiles by different abiotic and biotic stresses, but the stress-dependent emissions have been largely neglected in emission measurements and models. This presentation provides an overview of systematic screening of stress-dependent volatile emissions from a broad range of structurally and physiologically divergent plant species from temperate to tropical ecosystems. Ozone, heat, drought and wounding stress were the abiotic stresses considered in the screening, while biotic stress included herbivory, chemical elicitors simulating herbivory and fungal infections. The data suggest that any moderate to severe stress leads to significant emissions of a rich blend of volatiles, including methanol, green leaf volatiles (the lipoxygenase pathway volatiles, dominated by C6 aldehydes, alcohols and derivatives), different mono- and sesquiterpenes and benzenoids. The release of volatiles occurs in stress severity-dependent manner, although the emission responses are often non-linear with more severe stresses resulting in disproportionately greater emissions. Stress volatile release is induced in both non-constitutive and constitutive volatile emitters, whereas the rate of constitutive volatile emissions in constitutive emitters is often reduced under environmental and biotic stresses. Given that plants in natural conditions often experience stress, this analysis suggests that global volatile emissions have been significantly underestimated. Furthermore, in globally changing hotter climates, the frequency and severity of both abiotic and biotic stresses is expected to increase. Thus, the stress-induced volatile emissions are predicted to play a dominant role in plant-atmosphere interactions in near future. Quantitative models that link stress severity, plant volatile emissions and climatic feedbacks are currently being developed, and this presentation argues that incorporating stress-dependent feedbacks in Earth system models in inevitable to simulate future climates.

Biotic and abiotic factors affect green ash volatile production and emerald ash borer adult feeding preference.

PubMed

Chen, Yigen; Poland, Therese M

2009-12-01

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is an exotic woodborer first detected in 2002 in Michigan and Ontario and is threatening the ash resource in North America. We examined the effects of light exposure and girdling on green ash (Fraxinus pennsylvanica Marsh) volatile production, and effects of light exposure, girdling, and leaf age on emerald ash borer adult feeding preferences and phototaxis. Green ash seedlings grown under higher light exposure had lower amounts of three individual volatile compounds, (Z)-3-hexenol, (E)-beta-ocimene, and (Z,E)-alpha-farnesene, as well as the total amount of six detected volatile compounds. Girdling did not affect the levels of these volatiles. Emerald ash borer females preferred mature leaves, leaves from girdled trees, and leaves grown in the sun over young leaves, leaves from nongirdled trees, and leaves grown in the shade, respectively. These emerald ash borer preferences were most likely because of physical, nutritional, or biochemical changes in leaves in response to the different treatments. Emerald ash borer females and males showed positive phototaxis in laboratory arenas, a response consistent with emerald ash borer preference for host trees growing in sunlight.

Volatiles released from Vaccinium corymbosum were attractive to Aegorhinus superciliosus (Coleoptera: Curculionidae) in an olfactometric bioassay.

PubMed

Parra, Leonardo; Mutis, Ana; Ceballos, Ricardo; Lizama, Marcelo; Pardo, Fernando; Perich, Fernando; Quiroz, Andrés

2009-06-01

The objective of this study was to evaluate the role of host volatiles in the relationship between a blueberry plant Vaccinium corymbosum L. and the raspberry weevil Aegorhinus superciliosus (Guérin) (Coleoptera: Curculionidae), the principal pest of blueberry in the south of Chile. Volatiles from the aerial part of different phenological stages of the host were collected on Porapak Q and analyzed by coupled gas chromatography-mass spectrometry (GC-MS). Several chemical groups were identified including green leaf volatiles, aromatic compounds, and terpenes. The olfactometric responses of A. superciliosus toward different odor sources were studied in a four-arm olfactometer. Blueberry shoots at the phenological stages of fruit set, and blue-pink fruit color elicited the greatest behavioral responses from weevils. Five compounds (2-nonanone, eucalyptol, R- and S-limonene, and 4-ethyl benzaldehyde) elicited an attractant behavioral response from A. superciliosus. The results suggest the host location behavior of A. superciliosus could be mediated by volatiles derived from V. corymbosum. This work has identified a number of compounds with which it is possible to develop a lure for the principal pest of blueberry in southern Chile.

SOA formation potential of emissions from soil and leaf litter.

PubMed

Faiola, Celia L; Vanderschelden, Graham S; Wen, Miao; Elloy, Farah C; Cobos, Douglas R; Watts, Richard J; Jobson, B Thomas; Vanreken, Timothy M

2014-01-21

Soil and leaf litter are significant global sources of small oxidized volatile organic compounds, VOCs (e.g., methanol and acetaldehyde). They may also be significant sources of larger VOCs that could act as precursors to secondary organic aerosol (SOA) formation. To investigate this, soil and leaf litter samples were collected from the University of Idaho Experimental Forest and transported to the laboratory. There, the VOC emissions were characterized and used to drive SOA formation via dark, ozone-initiated reactions. Monoterpenes dominated the emission profile with emission rates as high as 228 μg-C m(-2) h(-1). The composition of the SOA produced was similar to biogenic SOA formed from oxidation of ponderosa pine emissions and α-pinene. Measured soil and litter monoterpene emission rates were compared with modeled canopy emissions. Results suggest surface soil and litter monoterpene emissions could range from 12 to 136% of canopy emissions in spring and fall. Thus, emissions from leaf litter may potentially extend the biogenic emissions season, contributing to significant organic aerosol formation in the spring and fall when reduced solar radiation and temperatures reduce emissions from living vegetation.

Biogenic volatile organic compound emissions from senescent maize leaves and a comparison with other leaf developmental stages

NASA Astrophysics Data System (ADS)

Mozaffar, A.; Schoon, N.; Bachy, A.; Digrado, A.; Heinesch, B.; Aubinet, M.; Fauconnier, M.-L.; Delaplace, P.; du Jardin, P.; Amelynck, C.

2018-03-01

Plants are the major source of Biogenic Volatile Organic Compounds (BVOCs) which have a large influence on atmospheric chemistry and the climate system. Therefore, understanding of BVOC emissions from all abundant plant species at all developmental stages is very important. Nevertheless, investigations on BVOC emissions from even the most widespread agricultural crop species are rare and mainly confined to the healthy green leaves. Senescent leaves of grain crop species could be an important source of BVOCs as almost all the leaves senesce on the field before being harvested. For these reasons, BVOC emission measurements have been performed on maize (Zea mays L.), one of the most cultivated crop species in the world, at all the leaf developmental stages. The measurements were performed in controlled environmental conditions using dynamic enclosures and proton transfer reaction mass spectrometry (PTR-MS). The main compounds emitted by senescent maize leaves were methanol (31% of the total cumulative BVOC emission on a mass of compound basis) and acetic acid (30%), followed by acetaldehyde (11%), hexenals (9%) and m/z 59 compounds (acetone/propanal) (7%). Important differences were observed in the temporal emission profiles of the compounds, and both yellow leaves during chlorosis and dry brown leaves after chlorosis were identified as important senescence-related BVOC sources. Total cumulative BVOC emissions from senescent maize leaves were found to be among the highest for senescent Poaceae plant species. BVOC emission rates varied strongly among the different leaf developmental stages, and senescent leaves showed a larger diversity of emitted compounds than leaves at earlier stages. Methanol was the compound with the highest emissions for all the leaf developmental stages and the contribution from the young-growing, mature, and senescent stages to the total methanol emission by a typical maize leaf was 61, 13, and 26%, respectively. This study shows that BVOC emissions from senescent maize leaves cannot be neglected and further investigations in field conditions are recommended to further constrain the BVOC emissions from this important C4 crop species.

[Elimination of volatile compounds of leaf tobacco from air emissions using biofiltration].

PubMed

Zagustina, N A; Misharina, T A; Vepritskiĭ, A A; Zhukov, V G; Ruzhitskiĭ, A O; Terenina, M B; Krikunova, N I; Kulikova, A K; Popov, V O

2012-01-01

The composition of the volatile organic compounds (VOCs) of various leaf tobacco brands and their blends has been studied. The differences in the content of nicotine, solanone, tetramethyl hexadecenol, megastigmatrienones, and other compounds, determining the specific tobacco smell, have been revealed. A microbial consortium, which is able to deodorize simulated tobacco emissions and decompose nicotine, has been formed by long-term adaptation to the VOCs of tobacco leaves in a laboratory reactor, functioning as a trickle-bed biofilter. Such a biofilter eliminates 90% of the basic toxic compound (nicotine) and odor-active compounds; the filtration efficiency does not change for tobacco brands with different VOC concentrations or in the presence of foreign substances. The main strains, isolated from the formed consortium and participating in the nicotine decomposition process, belong to the genera Pseudomonas, Bacillus, and Rhodococcus. An examination of the biofilter trickling fluid has shown full decomposition of nicotine and odor-active VOCs. The compounds, revealed in the trickling fluid, did not have any odor and were nontoxic. The obtained results make it possible to conduct scaling of the biofiltration process to eliminate odor from air emissions in the tobacco industry.

Enhanced attraction of Plutella xylostella (Lepidoptera: Plutellidae) to pheromone-baited traps with the addition of green leaf volatiles.

PubMed

Li, Pengyan; Zhu, Junwei; Qin, Yuchuan

2012-08-01

Diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is one of the most serious pests of Brassicaceae crops worldwide. Electrophysiological and behavioral responses of P. xylostella to green leaf volatiles (GLVs) alone or together with its female sex pheromone were investigated in laboratory and field. GLVs 1-hexanol and (Z)-3-hexen-1-ol elicited strong electroantennographic responses from unmated male and female P. xylostella, whereas (Z)-3-hexenyl acetate only produced a relatively weak response. The behavioral responses of unmated moths to GLVs were further tested in Y-tube olfactometer experiments. (E)-2-Hexenal, (Z)-3-hexen-1-ol, and (Z)-3-hexenyl acetate induced attraction of males, reaching up to 50%, significantly higher than the response to the unbaited control arm. In field experiments conducted in 2008 and 2009, significantly more moths were captured in traps baited with synthetic sex pheromone with either (Z)-3-hexenyl acetate alone or a blend of (Z)-3-hexenyl acetate, (Z)-3-hexen-1-ol, and (E)-2-hexenal compared with sex pheromone alone and other blend mixtures. These results demonstrated that GLVs could be used to enhance the attraction of P. xylostella males to sex pheromone-baited traps.

[Effects of applying controlled-release fertilizer blended with conventional nitrogen fertilizer on Chinese cabbage yield and quality as well as nitrogen losses].

PubMed

Yang, Jun-gang; Xu, Kai; Tong, Er-jian; Cao, Bing; Ni, Xiao-hui; Xu, Jun-xiang

2010-12-01

An open field experiment was conducted to study the effects of applying controlled-release fertilizer blended with rapidly available chemical N fertilizer on Chinese cabbage yield and quality as well as nitrogen losses, including ammonia volatilization and NO3- -N accumulation and leaching in Beijing suburb. The results showed that a combined application of 2:1 controlled-release fertilizer and urea fertilizer (total N rate 150 kg x hm(-2)) did not induce the reduction of Chinese cabbage yield, and decreased the leaf nitrate and organic acid contents significantly, compared with conventional urea N application (300 kg x hm(-2)), and had no significant difference in the cabbage yield and leaf nitrate content, compared with applying 150 kg x hm(-2) of urea N. The combined application of 2:1 controlled-release fertilizer and urea fertilizer improved the N use efficiency of Chinese cabbage, and reduced the ammonia volatilization and NO3- -N leaching. At harvest, the NO3- -N concentrations in 20-40, 60-80 and 80-100 cm soil layers were significantly lower in the combined application treatment than in urea N treatment.

Antifungal activity of volatile compounds generated by essential oils against fungi commonly causing deterioration of bakery products.

PubMed

Guynot, M E; Ramos, A J; Setó, L; Purroy, P; Sanchis, V; Marín, S

2003-01-01

To investigate the volatile fractions of 16 essential oils for activity against the more common fungi causing spoilage of bakery products, Eurotium amstelodami, E. herbariorum, E. repens, E. rubrum, Aspergillus flavus, A. niger and Penicillium corylophilum. The study applied 50 microl of pure essential oils in a sterilized filter paper, were carried out at pH 6 and at different water activity levels (0.80-0.90). First, a wheat flour based agar medium was used, where cinnamon leaf, clove, bay, lemongrass and thyme essential oils where found to totally inhibit all microorganisms tested. These five essential oils were then tested in sponge cake analogues, but the antifungal activity detected was much more limited. Five essential oils showed potential antifungal capacity against all species tested, over a wide range of water availability. Their activity, however, seems to be substrate-dependent. More research is needed to make them work in real bakery products, as in the preliminary study limited effectiveness was found. The potential of the cinnamon leaf, clove, bay, lemongrass and thyme essential oils against species belonging to Eurotium, Aspergillus and Penicillium genus has been demonstrated.

Final Technical Report summarizing Purdue research activities as part of the DOE JET Topical Collaboration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Molnar, Denes

2015-09-01

This report summarizes research activities at Purdue University done as part of the DOE JET Topical Collaboration. These mainly involve calculation of covariant radiative energy loss in the (Djordjevic-)Gyulassy-Levai-Vitev ((D)GLV) framework for relativistic A+A reactions at RHIC and LHC energies using realistic bulk medium evolution with both transverse and longitudinal expansion. The single PDF file provided also includes a report from the entire JET Collaboration.

Oncolytic vaccinia virus combined with radiotherapy induces apoptotic cell death in sarcoma cells by down-regulating the inhibitors of apoptosis

PubMed Central

Wilkinson, Michelle J.; Smith, Henry G.; McEntee, Gráinne; Kyula-Currie, Joan; Mansfield, David C.; Khan, Aadil A.; Roulstone, Victoria

2016-01-01

Advanced extremity melanoma and sarcoma present a significant therapeutic challenge, requiring multimodality therapy to treat or even palliate disease. These aggressive tumours are relatively chemo-resistant, therefore new treatment approaches are urgently required. We have previously reported on the efficacy of oncolytic virotherapy (OV) delivered by isolated limb perfusion. In this report, we have improved therapeutic outcomes by combining OV with radiotherapy. In vitro, the combination of oncolytic vaccinia virus (GLV-1h68) and radiotherapy demonstrated synergistic cytotoxicity. This effect was not due to increased viral replication, but mediated through induction of intrinsic apoptosis. GLV-1h68 therapy downregulated the anti-apoptotic BCL-2 proteins (MCL-1 and BCL-XL) and the downstream inhibitors of apoptosis, resulting in cleavage of effector caspases 3 and 7. In an in vivo ILP model, the combination of OV and radiotherapy significantly delayed tumour growth and prolonged survival compared to single agent therapy. These data suggest that the virally-mediated down-regulation of anti-apoptotic proteins may increase the sensitivity of tumour cells to the cytotoxic effects of ionizing radiation. Oncolytic virotherapy represents an exciting candidate for clinical development when delivered by ILP. Its ability to overcome anti-apoptotic signals within tumour cells points the way to further development in combination with conventional anti-cancer therapies. PMID:27783991

1996-2007 Interannual Spatio-Temporal Variability in Snowmelt in Two Montane Watersheds

NASA Astrophysics Data System (ADS)

Jepsen, S. M.; Molotch, N. P.; Rittger, K. E.

2009-12-01

Snowmelt is a primary water source for ecosystems within, and urban/agricultural centers near, mountain regions. Stream chemistry from montane catchments is controlled by the flowpaths of water from snowmelt and the timing and duration of snow coverage. A process level understanding of the variability in these processes requires an understanding of the effect of changing climate and anthropogenic loading on spatio-temporal snowmelt patterns. With this as our objective, we are applying a snow reconstruction model to two well-studied montane watersheds, Tokopah Basin (TOK), California and Green Lakes Valley (GLV), Colorado, to examine interannual variability in the timing and location of snowmelt in response to variable climate conditions during the period from 1996 to 2007. The reconstruction model back solves for snowmelt by combining surface energy fluxes, inferred from meteorological data, with sequences of melt season snow images derived from satellite data (i.e., snowmelt depletion curves). Preliminary model results for 2002 were tested against measured snow water equivalent (SWE) and hydrograph data for the two watersheds. The computed maximum SWE averaged over TOK and GLV were 94 cm (~+17% error) and 50.2 cm (~+1% error), respectively. We present an analysis of interannual variability in these errors, in addition to reconstructed snowmelt maps over different land cover types under changing climate conditions between 1996-2007, focusing on the variability with interannual variation in climate.

Reforming health care for the elderly--the example of Vorarlberg.

PubMed

Badelt, C

1987-01-01

Vorarlberg--Austria's most western province with a population of about 325,000--has always implemented forms of social policy in which the principles of subsidiarity and solidarity play an important role. This is reflected in the structure of the organizations traditionally providing social services as well as in the more recent programmes the government has developed for social policy. This paper discusses two cases in point: the private associations for home care (Krankenpflegerverbände)--which now exist in 65 Vorarlberg communities and cover 85% of the population in the province--offering nursing services at home to members or to persons who are willing to join the organization when they need care, and the new organizational model, called Gesunder Lebensraum Vorarlberg (GLV), which is successfully operating in a few pilot communities. GLV has spawned umbrella organizations, run by volunteers, and offering a variety of social services relevant to the elderly, for example visiting services or neighbourhood help in case of emergencies. The volunteers get organizational help from a profit-making firm financed by the government. The Vorarlberg models can be interpreted as a step towards demedicalization and deinstitutionalization of health care for the elderly. Nevertheless, they also show the problems that arise when professionals and volunteers must cooperate. The models may lead to savings for the governments involved, although details are still subject to future empirical investigations.

Leaf Volatile Compounds and Associated Gene Expression during Short-Term Nitrogen Deficient Treatments in Cucumis Seedlings

PubMed Central

Deng, Jie; Yu, Hong-Jun; Li, Yun-Yun; Zhang, Xiao-Meng; Liu, Peng; Li, Qiang; Jiang, Wei-Jie

2016-01-01

Nitrogen (N) is an important macronutrient for plant growth and development, but the regulatory mechanism of volatile compounds in response to N deficiency is not well understood, especially in cucumber, which consumes excessive N during growth. In this study, the major volatile compounds from cucumber leaves subjected to N deficiency were analyzed by GC-MS. A total of 24 volatile components were identified including 15 aldehydes, two ketones, two alkenes, and five other volatile compounds in 9930 leaves. Principal component analysis using volatile compounds from cucumber leaves provided good separation between N-sufficient and N-deficient treatments. The main volatiles in cucumber leaves were found to be C6 and C9 aldehydes, especially (E)-2-hexanal and (E,Z)-2,6-nonadienal. (E)-2-hexanal belonged to the C6 aldehyde and was the most abundant compound, whereas (E,Z)-2,6-nonadienal was the chief component of C9 aldehydes. During N-deficient treatment, short-chain volatile content was significantly improved at 5 day, other volatiles displayed significant reduction or no significantly changes in all sampling points. Improvement of short-chain volatiles was confirmed in the six other inbred lines at 5 day after N-deficient treatments. The expression analysis of 12 cucumber LOX genes and two HPL genes revealed that CsLOX19, CsLOX20, and CsLOX22 had common up-regulated expression patterns in response to N-deficient stress in most inbred lines; meanwhile, most sample points of CsHPL1 also had significant up-regulated expression patterns. This research focused on the relationship between volatiles in cucumber and different nitrogen environments to provide valuable insight into the effect of cultivation and management of the quality of cucumber and contributes to further research on volatile metabolism in cucumber. PMID:27827841

Ozone-induced foliar damage and release of stress volatiles is highly dependent on stomatal openness and priming by low-level ozone exposure in Phaseolus vulgaris.

PubMed

Li, Shuai; Harley, Peter C; Niinemets, Ülo

2017-09-01

Acute ozone exposure triggers major emissions of volatile organic compounds (VOCs), but quantitatively, it is unclear how different ozone doses alter the start and the total amount of these emissions, and the induction rate of different stress volatiles. It is also unclear whether priming (i.e. pre-exposure to lower O 3 concentrations) can modify the magnitude and kinetics of volatile emissions. We investigated photosynthetic characteristics and VOC emissions in Phaseolus vulgaris following acute ozone exposure (600 nmol mol -1 for 30 min) under illumination and in darkness and after priming with 200 nmol mol -1 O 3 for 30 min. Methanol and lipoxygenase (LOX) pathway product emissions were induced rapidly, followed by moderate emissions of methyl salicylate (MeSA). Stomatal conductance prior to acute exposure was lower in darkness and after low O 3 priming than in light and without priming. After low O 3 priming, no MeSA and lower LOX emissions were detected under acute exposure. Overall, maximum emission rates and the total amount of emitted LOX products and methanol were quantitatively correlated with total stomatal ozone uptake. These results indicate that different stress volatiles scale differently with ozone dose and highlight the key role of stomatal conductance in controlling ozone uptake, leaf injury and volatile release. © 2017 John Wiley & Sons Ltd.

Elevated O3 enhances the attraction of whitefly-infested tomato plants to Encarsia formosa

PubMed Central

Cui, Hongying; Su, Jianwei; Wei, Jianing; Hu, Yongjian; Ge, Feng

2014-01-01

We experimentally examined the effects of elevated O3 and whitefly herbivory on tomato volatiles, feeding and oviposition preferences of whiteflies and behavioural responses of Encarsia formosa to these emissions on two tomato genotypes, a wild-type (Wt) and a jasmonic acid (JA) defence-enhanced genotype (JA-OE, 35S). The O3 level and whitefly herbivory significantly increased the total amount of volatile organic compounds (VOCs), monoterpenes, green leaf volatiles (GLVs), and aldehyde volatiles produced by tomato plants. The 35S plants released higher amount of total VOCs and monoterpene volatiles than Wt plants under O3+herbivory treatments. The feeding and oviposition bioassays showed that control plants were preferred by adult whiteflies whereas the 35S plants were not preferred by whiteflies. In the Y-tube tests, O3+herbivory treatment genotypes were preferred by adult E. Formosa. The 35S plants were preferred by adult E. formosa under O3, herbivory and O3+herbivory treatments. Our results demonstrated that elevated O3 and whitefly herbivory significantly increased tomato volatiles, which attracted E. formosa and reduced whitefly feeding. The 35S plants had a higher resistance to B. tabaci than Wt plant. Such changes suggest that the direct and indirect defences of resistant genotypes, such as 35S, could strengthen as the atmospheric O3 concentration increases. PMID:24939561

Ozone-induced foliar damage and release of stress volatiles is highly dependent on stomatal openness and priming by low-level ozone exposure in Phaseolus vulgaris

PubMed Central

Li, Shuai; Harley, Peter C.; Niinemets, Ülo

2018-01-01

Acute ozone exposure triggers major emissions of volatile organic compounds (VOC), but quantitatively, it is unclear how different ozone doses alter the start and the total amount of these emissions, and the induction rate of different stress volatiles. It is also unclear whether priming (i.e., pre-exposure to lower O3 concentrations) can modify the magnitude and kinetics of volatile emissions. We investigated photosynthetic characteristics and VOC emissions in Phaseolus vulgaris following acute ozone exposure (600 nmol mol-1 for 30 min) under illumination and in darkness and after priming with 200 nmol mol-1 O3 for 30 min. Methanol and lipoxygenase (LOX) pathway product emissions were induced rapidly, followed by moderate emissions of methyl salicylate (MeSA). Stomatal conductance prior to acute exposure was lower in darkness and after low O3 priming than in light and without priming. After low O3 priming, no MeSA and lower LOX emissions were detected under acute exposure. Overall, maximum emission rates and the total amount of emitted LOX products and methanol were quantitatively correlated with total stomatal ozone uptake. These results indicate that different stress volatiles scale differently with ozone dose and highlight the key role of stomatal conductance in controlling ozone uptake, leaf injury and volatile release. PMID:28623868

Non-pathogenic rhizobacteria interfere with the attraction of parasitoids to aphid-induced plant volatiles via jasmonic acid signalling.

PubMed

Pineda, Ana; Soler, Roxina; Weldegergis, Berhane T; Shimwela, Mpoki M; VAN Loon, Joop J A; Dicke, Marcel

2013-02-01

Beneficial soil-borne microbes, such as mycorrhizal fungi or rhizobacteria, can affect the interactions of plants with aboveground insects at several trophic levels. While the mechanisms of interactions with herbivorous insects, that is, the second trophic level, are starting to be understood, it remains unknown how plants mediate the interactions between soil microbes and carnivorous insects, that is, the third trophic level. Using Arabidopsis thaliana Col-0 and the aphid Myzus persicae, we evaluate here the underlying mechanisms involved in the plant-mediated interaction between the non-pathogenic rhizobacterium Pseudomonas fluorescens and the parasitoid Diaeretiella rapae, by combining ecological, chemical and molecular approaches. Rhizobacterial colonization modifies the composition of the blend of herbivore-induced plant volatiles. The volatile blend from rhizobacteria-treated aphid-infested plants is less attractive to an aphid parasitoid, in terms of both olfactory preference behaviour and oviposition, than the volatile blend from aphid-infested plants without rhizobacteria. Importantly, the effect of rhizobacteria on both the emission of herbivore-induced volatiles and parasitoid response to aphid-infested plants is lost in an Arabidopsis mutant (aos/dde2-2) that is impaired in jasmonic acid production. By modifying the blend of herbivore-induced plant volatiles that depend on the jasmonic acid-signalling pathway, root-colonizing microbes interfere with the attraction of parasitoids of leaf herbivores. © 2012 Blackwell Publishing Ltd.

Elevated O3 increases volatile organic compounds via jasmonic acid pathway that promote the preference of parasitoid Encarsia formosa for tomato plants.

PubMed

Cui, Hongying; Wei, Jianing; Su, Jianwei; Li, Chuanyou; Ge, Feng

2016-12-01

The elevated atmospheric O 3 level may change the interactions of plants and insects, which potentially affects direct and indirect plant defences. However, the underlying mechanism of the impact of elevated O 3 on indirect plant defence, namely the efficacy of natural enemies, is unclear. Here we tested a hypothesis that linked the effects of elevated O 3 and whitefly herbivory on tomato volatile releases mediated by the jasmonic acid (JA) pathway with the preferences of parasitoid Encarsia formosa for two different tomato genotypes (wild-type (Wt) and JA-deficient genotype (spr2)). The O 3 and whitefly herbivory significantly increased the production of volatile organic compounds (VOCs), including monoterpenes and green leaf volatiles (GLVs). The Wt plants released higher volatile levels, particularly monoterpenes, than did the spr2 plants. In Y-tube tests, limonene and Z-3-hexanol played key roles in the attraction of E. formosa. Moreover, regardless of plant genotype, the two plant genotypes were preferred by adult E. formosa under the O 3 and O 3 + herbivory treatments. Our results suggest that under elevated O 3 , the activation of the JA pathway significantly up-regulates the emission rates of volatiles, through which the efficacy of natural enemy might be promoted. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

NAC Transcription Factor SPEEDY HYPONASTIC GROWTH Regulates Flooding-Induced Leaf Movement in Arabidopsis[W

PubMed Central

Rauf, Mamoona; Arif, Muhammad; Fisahn, Joachim; Xue, Gang-Ping; Balazadeh, Salma; Mueller-Roeber, Bernd

2013-01-01

In rosette plants, root flooding (waterlogging) triggers rapid upward (hyponastic) leaf movement representing an important architectural stress response that critically determines plant performance in natural habitats. The directional growth is based on localized longitudinal cell expansion at the lower (abaxial) side of the leaf petiole and involves the volatile phytohormone ethylene (ET). We report the existence of a transcriptional core unit underlying directional petiole growth in Arabidopsis thaliana, governed by the NAC transcription factor SPEEDY HYPONASTIC GROWTH (SHYG). Overexpression of SHYG in transgenic Arabidopsis thaliana enhances waterlogging-triggered hyponastic leaf movement and cell expansion in abaxial cells of the basal petiole region, while both responses are largely diminished in shyg knockout mutants. Expression of several EXPANSIN and XYLOGLUCAN ENDOTRANSGLYCOSYLASE/HYDROLASE genes encoding cell wall–loosening proteins was enhanced in SHYG overexpressors but lowered in shyg. We identified ACC OXIDASE5 (ACO5), encoding a key enzyme of ET biosynthesis, as a direct transcriptional output gene of SHYG and found a significantly reduced leaf movement in response to root flooding in aco5 T-DNA insertion mutants. Expression of SHYG in shoot tissue is triggered by root flooding and treatment with ET, constituting an intrinsic ET-SHYG-ACO5 activator loop for rapid petiole cell expansion upon waterlogging. PMID:24363315

NAC transcription factor speedy hyponastic growth regulates flooding-induced leaf movement in Arabidopsis.

PubMed

Rauf, Mamoona; Arif, Muhammad; Fisahn, Joachim; Xue, Gang-Ping; Balazadeh, Salma; Mueller-Roeber, Bernd

2013-12-01

In rosette plants, root flooding (waterlogging) triggers rapid upward (hyponastic) leaf movement representing an important architectural stress response that critically determines plant performance in natural habitats. The directional growth is based on localized longitudinal cell expansion at the lower (abaxial) side of the leaf petiole and involves the volatile phytohormone ethylene (ET). We report the existence of a transcriptional core unit underlying directional petiole growth in Arabidopsis thaliana, governed by the NAC transcription factor speedy hyponastic growth (SHYG). Overexpression of SHYG in transgenic Arabidopsis thaliana enhances waterlogging-triggered hyponastic leaf movement and cell expansion in abaxial cells of the basal petiole region, while both responses are largely diminished in shyg knockout mutants. Expression of several expansin and xyloglucan endotransglycosylase/hydrolase genes encoding cell wall-loosening proteins was enhanced in SHYG overexpressors but lowered in shyg. We identified ACC oxidase5 (ACO5), encoding a key enzyme of ET biosynthesis, as a direct transcriptional output gene of SHYG and found a significantly reduced leaf movement in response to root flooding in aco5 T-DNA insertion mutants. Expression of SHYG in shoot tissue is triggered by root flooding and treatment with ET, constituting an intrinsic ET-SHYG-ACO5 activator loop for rapid petiole cell expansion upon waterlogging.

Fungal succession in relation to volatile organic compounds emissions from Scots pine and Norway spruce leaf litter-decomposing fungi

NASA Astrophysics Data System (ADS)

Isidorov, Valery; Tyszkiewicz, Zofia; Pirożnikow, Ewa

2016-04-01

Leaf litter fungi are partly responsible for decomposition of dead material, nutrient mobilization and gas fluxes in forest ecosystems. It can be assumed that microbial destruction of dead plant materials is an important source of volatile organic compounds (VOCs) emitted into the atmosphere from terrestrial ecosystems. However, little information is available on both the composition of fungal VOCs and their producers whose community can be changed at different stages of litter decomposition. The fungal community succession was investigated in a litter bag experiment with Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) needle litter. The succession process can be divided into a several stages controlled mostly by changes in litter quality. At the very first stages of decomposition the needle litter was colonized by ascomycetes which can use readily available carbohydrates. At the later stages, the predominance of Trichoderma sp., the known producers of cellulolytic enzymes, was documented. To investigate the fungi-derived VOCs, eight fungi species were isolated. As a result of gas chromatographic analyses, as many as 75C2sbnd C15 fungal volatile compounds were identified. Most components detected in emissions were very reactive substances: the principal groups of VOCs were formed by monoterpenes, carbonyl compounds and aliphatic alcohols. It was found that production of VOCs by fungi is species specific: only 10 metabolites were emitted into the gas phase by all eight species. The reported data confirm that the leave litter decomposition is important source of reactive organic compounds under the forest canopy.

Changes in photosynthetic rate and stress volatile emissions through desiccation-rehydration cycles in desiccation-tolerant epiphytic filmy ferns (Hymenophyllaceae).

PubMed

Niinemets, Ülo; Bravo, León A; Copolovici, Lucian

2018-07-01

Exposure to recurrent desiccation cycles carries a risk of accumulation of reactive oxygen species that can impair leaf physiological activity upon rehydration, but changes in filmy fern stress status through desiccation and rewatering cycles have been poorly studied. We studied foliage photosynthetic rate and volatile marker compounds characterizing cell wall modifications (methanol) and stress development (lipoxygenase [LOX] pathway volatiles and methanol) through desiccation-rewatering cycles in lower-canopy species Hymenoglossum cruentum and Hymenophyllum caudiculatum, lower- to upper-canopy species Hymenophyllum plicatum and upper-canopy species Hymenophyllum dentatum sampled from a common environment and hypothesized that lower canopy species respond more strongly to desiccation and rewatering. In all species, rates of photosynthesis and LOX volatile emission decreased with progression of desiccation, but LOX emission decreased with a slower rate than photosynthesis. Rewatering first led to an emission burst of LOX volatiles followed by methanol, indicating that the oxidative burst was elicited in the symplast and further propagated to cell walls. Changes in LOX emissions were more pronounced in the upper-canopy species that had a greater photosynthetic activity and likely a greater rate of production of photooxidants. We conclude that rewatering induces the most severe stress in filmy ferns, especially in the upper canopy species. © 2018 John Wiley & Sons Ltd.

Molecular cloning and expression of Hedychium coronarium farnesyl pyrophosphate synthase gene and its possible involvement in the biosynthesis of floral and wounding/herbivory induced leaf volatile sesquiterpenoids.

PubMed

Lan, Jian-bin; Yu, Rang-cai; Yu, Yun-yi; Fan, Yan-ping

2013-04-15

Farnesyl pyrophosphate synthase (FPPS EC 2.5.1.10) catalyzes the production of farnesyl pyrophosphate (FPP), which is a key precursor for many sesquiterpenoids such as floral scent and defense volatiles against herbivore attack. Here we report a new full-length cDNA encoding farnesyl diphosphate synthase from Hedychium coronarium. The open reading frame for full-length HcFPPS encodes a protein of 356 amino acids, which is 1068 nucleotides long with calculated molecular mass of 40.7 kDa. Phylogenetic tree analysis indicates that HcFPPS belongs to the plant FPPS super-family and has strong relationship with FPPS from Musa acuminata. Expression of the HcFPPS gene in Escherichia coli yielded FPPS activity. Tissue-specific and developmental analyses of the HcFPPS mRNA and corresponding volatile sesquiterpenoid levels in H. coronarium flowers revealed that the HcFPPS might play a regulatory role in floral volatile sesquiterpenoid biosynthesis. The emission of the FPP-derived volatile terpenoid correlates with strong expression of HcFPPS induced by mechanical wounding and Udaspes folus-damage in leaves, which suggests that HcFPPS may have an important ecological function in H. coronarium vegetative organ. Copyright © 2013 Elsevier B.V. All rights reserved.

Taxonomy, Traits, and Environment Determine Isoprenoid Emission from an Evergreen Tropical forest.

NASA Astrophysics Data System (ADS)

Taylor, T.; Alves, E. G.; Tota, J.; Oliveira Junior, R. C.; Camargo, P. B. D.; Saleska, S. R.

2016-12-01

Volatile isoprenoid emissions from the leaves of tropical forest trees significantly affects atmospheric chemistry, aerosols, and cloud dynamics, as well as the physiology of the emitting leaves. Emission is associated with plant tolerance to heat and drought stress. Despite a potentially central role of isoprenoid emissions in tropical forest-climate interactions, we have a poor understanding of the relationship between emissions and ecological axes of forest function. We used a custom instrument to quantify leaf isoprenoid emission rates from over 200 leaves and 80 trees at a site in the eastern Brazilian Amazon. We related standardized leaf emission capacity (EC: leaf emission rate at 1000 PAR) to tree taxonomy, height, light environment, wood traits, and leaf traits. Taxonomy was the strongest predictor of EC, and non-emitters could be found throughout the canopy. But we found that environment and leaf carbon economics constrained the upper bound of EC. For example, the relationship between EC and specific leaf area (SLA; fresh leaf area / dry mass) is described by an envelope with a decreasing upper bound on EC as SLA increases (quantile regression: 85th quantile, p<0.01). That result suggests a limitation on emissions related to leaf carbon investment strategies. EC was highest in the mid-canopy, and in leaves growing under less direct light. While inferences of ecosystem emissions focus on environmental conditions in the canopy, our results suggest that sub-canopy leaves are more responsive. This work is allowing us to develop an ecological understanding of isoprenoid emissions from forests, the basis for a predictive model of emissions that depends on both environmental factors and biological emission capacity that is grounded in plant traits and phylogeny.

SOA formation potential of emissions from soil and leaf litter

DOE PAGES

Faiola, Celia L.; VanderSchelden, Graham S.; Wen, Miao; ...

2013-12-13

Soil and leaf litter are significant global sources of small oxidized volatile organic compounds, VOCs (e.g., methanol and acetaldehyde). They may also be significant sources of larger VOCs that could act as precursors to secondary organic aerosol (SOA) formation. To investigate this, soil and leaf litter samples were collected from the University of Idaho Experimental Forest and transported to the laboratory. There, the VOC emissions were characterized and used to drive SOA formation via dark, ozone-initiated reactions. Monoterpenes dominated the emission profile with emission rates as high as 228 μg-C m –2 h –1. The composition of the SOA producedmore » was similar to biogenic SOA formed from oxidation of ponderosa pine emissions and α-pinene. Measured soil and litter monoterpene emission rates were compared with modeled canopy emissions. Results suggest surface soil and litter monoterpene emissions could range from 12 to 136% of canopy emissions in spring and fall. Furthermore, emissions from leaf litter may potentially extend the biogenic emissions season, contributing to significant organic aerosol formation in the spring and fall when reduced solar radiation and temperatures reduce emissions from living vegetation.« less

Extraction, separation and isolation of volatiles from Vitex agnus-castus L. (Verbenaceae) wild species of Sardinia, Italy, by supercritical CO2.

PubMed

Marongiu, Bruno; Piras, Alessandra; Porcedda, Silvia; Falconieri, Danilo; Goncalves, Maria J; Salgueiro, Ligia; Maxia, Andrea; Lai, Roberta

2010-04-01

Isolation of volatile concentrates from leaves, flowers and fruits of Vitex agnus-castus L. have been obtained by supercritical extraction with carbon dioxide. The composition of the volatile concentrates has been analysed by GC/MS. In all plant organs, the extracts are composed chiefly of alpha-pinene, sabinene, 1,8-cineole, alpha-terpinyl acetate, (E)-caryophyllene, (E)-beta-farnesene, bicyclogermacrene, spathulenol and manool. The main difference observed was in the content of sclarene, which was not present in the samples from flowers or fruits. To complete the investigation, a comparison with the hydrodistilled oil has been carried out. The minimal inhibitory concentration (MIC) and the minimal lethal concentration were used to evaluate the antifungal activity of the oils against dermatophyte strains (Trichophyton mentagrophytes, Microsporum canis, T. rubrum, M. gypseum and Epidermophyton floccosum). Antifungal activity of the leaf essential oil was the highest, with MIC values of 0.64 microL mL(-1) for most of the strains.

Exogenous polyamines elicit herbivore-induced volatiles in lima bean leaves: involvement of calcium, H2O2 and Jasmonic acid.

PubMed

Ozawa, Rika; Bertea, Cinzia M; Foti, Maria; Narayana, Ravishankar; Arimura, Gen-Ichiro; Muroi, Atsushi; Horiuchi, Jun-Ichiro; Nishioka, Takaaki; Maffei, Massimo E; Takabayashi, Junji

2009-12-01

We investigated the role of polyamines (PAs) in lima bean (Phaseolus lunatus) leaves on the production of herbivorous mite (Tetranychus urticae)-induced plant volatiles that attract carnivorous natural enemies of the herbivores. To do this, we focused on the effects of the exogenous PAs [cadaverine, putrescine, spermidine and spermine (Spm)] on the production of volatiles, H(2)O(2) and jasmonic acid (JA) and the levels of defensive genes, cytosolic calcium and reactive oxygen species (ROS). Among the tested PAs, Spm was the most active in inducing the production of volatile terpenoids known to be induced by T. urticae. An increase in JA levels was also found after Spm treatment, indicating that Spm induces the biosynthesis of JA, which has been shown elsewhere to regulate the production of some volatile terpenoids. Further, treatment with JA and Spm together resulted in greater volatile emission than that with JA alone. In a Y-tube olfactometer, leaves treated with Spm + JA attracted more predatory mites (Phytoseiulus persimilis) than those treated with JA alone. After treatment with Spm + JA, no effects were found on the enzyme activity of polyamine oxidase and copper amine oxidase. However, induction of calcium influx and ROS production, and increased enzyme activities and gene expression for NADPH oxidase complex, superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase and glutathione peroxidase were found after treatment with Spm + JA. These results indicate that Spm plays an important role in the production of T. urticae-induced lima bean leaf volatiles.

Rhizobacterial colonization of roots modulates plant volatile emission and enhances the attraction of a parasitoid wasp to host-infested plants.

PubMed

Pangesti, Nurmi; Weldegergis, Berhane T; Langendorf, Benjamin; van Loon, Joop J A; Dicke, Marcel; Pineda, Ana

2015-08-01

Beneficial root-associated microbes modify the physiological status of their host plants and affect direct and indirect plant defense against insect herbivores. While the effects of these microbes on direct plant defense against insect herbivores are well described, knowledge of the effect of the microbes on indirect plant defense against insect herbivores is still limited. In this study, we evaluate the role of the rhizobacterium Pseudomonas fluorescens WCS417r in indirect plant defense against the generalist leaf-chewing insect Mamestra brassicae through a combination of behavioral, chemical, and gene-transcriptional approaches. We show that rhizobacterial colonization of Arabidopsis thaliana roots results in an increased attraction of the parasitoid Microplitis mediator to caterpillar-infested plants. Volatile analysis revealed that rhizobacterial colonization suppressed the emission of the terpene (E)-α-bergamotene and the aromatics methyl salicylate and lilial in response to caterpillar feeding. Rhizobacterial colonization decreased the caterpillar-induced transcription of the terpene synthase genes TPS03 and TPS04. Rhizobacteria enhanced both the growth and the indirect defense of plants under caterpillar attack. This study shows that rhizobacteria have a high potential to enhance the biocontrol of leaf-chewing herbivores based on enhanced attraction of parasitoids.

Evaluation of double-decker traps for emerald ash borer (Coleoptera: Buprestidae).

PubMed

Poland, Therese M; McCullough, Deborah G; Anulewicz, Andrea C

2011-04-01

Improved detection tools are needed for the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), an invasive forest insect from Asia that has killed millions of ash (Fraxinus spp.) trees in North America since its discovery in Michigan in 2002. We evaluated attraction of adult A. planipennis to artificial traps incorporating visual (e.g., height, color, silhouette) and olfactory cues (e.g., host volatiles) at field sites in Michigan. We developed a double-decker trap consisting of a 3-m-tall polyvinyl pipe with two purple prisms attached near the top. In 2006, we compared A. planipennis attraction to double-decker traps baited with various combinations of manuka oil (containing sesquiterpenes present in ash bark), a blend of four ash leaf volatiles (leaf blend), and a rough texture to simulate bark. Significantly more A. planipennis were captured per trap when traps without the rough texture were baited with the leaf blend and manuka oil lures than on traps with texture and manuka oil but no leaf blend. In 2007, we also tested single prism traps set 1.5 m above ground and tower traps, similar to double-decker traps but 6 m tall. Double-decker traps baited with the leaf blend and manuka oil, with or without the addition of ash leaf and bark extracts, captured significantly more A. planipennis than similarly baited single prism traps, tower traps, or unbaited double-decker traps. A baited double-decker trap captured A. planipennis at a field site that was not previously known to be infested, representing the first detection event using artificial traps and lures. In 2008, we compared purple or green double-decker traps, single prisms suspended 3-5 m above ground in the ash canopy (canopy traps), and large flat purple traps (billboard traps). Significantly more A. planipennis were captured in purple versus green traps, baited traps versus unbaited traps, and double-decker versus canopy traps, whereas billboard traps were intermediate. At sites with very low A. planipennis densities, more A. planipennis were captured on baited double-decker traps than on other traps and a higher percentage of the baited double-decker traps captured beetles than any other trap design. In all 3 yr, peak A. planipennis activity occurred during late June to mid-July, corresponding to 800-1200 growing degree-days base 10 degrees C (DD10). Nearly all (95%) beetles were captured by the end of July at approximately 1400 DD10.

A memory efficient implementation scheme of Gauss error function in a Laguerre-Volterra network for neuroprosthetic devices

NASA Astrophysics Data System (ADS)

Li, Will X. Y.; Cui, Ke; Zhang, Wei

2017-04-01

Cognitive neural prosthesis is a manmade device which can be used to restore or compensate for lost human cognitive modalities. The generalized Laguerre-Volterra (GLV) network serves as a robust mathematical underpinning for the development of such prosthetic instrument. In this paper, a hardware implementation scheme of Gauss error function for the GLV network targeting reconfigurable platforms is reported. Numerical approximations are formulated which transform the computation of nonelementary function into combinational operations of elementary functions, and memory-intensive look-up table (LUT) based approaches can therefore be circumvented. The computational precision can be made adjustable with the utilization of an error compensation scheme, which is proposed based on the experimental observation of the mathematical characteristics of the error trajectory. The precision can be further customizable by exploiting the run-time characteristics of the reconfigurable system. Compared to the polynomial expansion based implementation scheme, the utilization of slice LUTs, occupied slices, and DSP48E1s on a Xilinx XC6VLX240T field-programmable gate array has decreased by 94.2%, 94.1%, and 90.0%, respectively. While compared to the look-up table based scheme, 1.0 ×1017 bits of storage can be spared under the maximum allowable error of 1.0 ×10-3 . The proposed implementation scheme can be employed in the study of large-scale neural ensemble activity and in the design and development of neural prosthetic device.

Corneal and Retinal Neuronal Degeneration in Early Stages of Diabetic Retinopathy.

PubMed

Srinivasan, Sangeetha; Dehghani, Cirous; Pritchard, Nicola; Edwards, Katie; Russell, Anthony W; Malik, Rayaz A; Efron, Nathan

2017-12-01

To examine the neuronal structural integrity of cornea and retina as markers for neuronal degeneration in nonproliferative diabetic retinopathy (NPDR). Participants were recruited from the broader Brisbane community, Queensland, Australia. Two hundred forty-one participants (187 with diabetes and 54 nondiabetic controls) were examined. Diabetic retinopathy (DR) was graded according to the Early Treatment Diabetic Retinopathy Study (ETDRS) scale. Corneal nerve fiber length (CNFL), corneal nerve branch density (CNBD), corneal nerve fiber tortuosity (CNFT), full retinal thickness, retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), focal (FLV) and global loss volumes (GLV), hemoglobin A1c (HbA1c), nephropathy, neuropathy, and cardiovascular measures were examined. The central zone (P = 0.174), parafoveal thickness (P = 0.090), perifovea (P = 0.592), RNFL (P = 0.866), GCC (P = 0.798), and GCC GLV (P = 0.338) did not differ significantly between the groups. In comparison to the control group, those with very mild NPDR and those with mild NPDR had significantly higher focal loss in GCC volume (P = 0.036). CNFL was significantly lower in those with mild NPDR (P = 0.004) in comparison to the control group and those with no DR. The CNBD (P = 0.094) and CNFT (P = 0.458) did not differ between the groups. Both corneal and retinal neuronal degeneration may occur in early stages of diabetic retinopathy. Further studies are required to examine these potential markers for neuronal degeneration in the absence of clinical signs of DR.

Developmental response of Spodoptera litura Fab. to treatments of crude volatile oil from Piper betle L. and evaluation of toxicity to earthworm, Eudrilus eugeniae Kinb.

PubMed

Vasantha-Srinivasan, Prabhakaran; Senthil-Nathan, Sengottayan; Thanigaivel, Annamalai; Edwin, Edward-Sam; Ponsankar, Athirstam; Selin-Rani, Selvaraj; Pradeepa, Venkatraman; Sakthi-Bhagavathy, Muthiah; Kalaivani, Kandaswamy; Hunter, Wayne B; Duraipandiyan, Veeramuthu; Al-Dhabi, Naif Abdullah

2016-07-01

Evaluations of biological effects of (Pb-CVO) the crude volatile oil of Piper betle leaves on the tobacco cutworm Spodoptera litura were conducted. Pb-CVO was subjected to GC-MS analysis and twenty vital compounds were isolated from the betel leaf oil. Pb-CVO was tested at four different concentrations (0.25, 0.5, 1.0 and 1.5%) against S. litura. The treated insects exhibited dose depended mortality. The mortality rate was significantly higher at the 1.0 and 1.5% Pb-CVO. The LC50 (Lethal concentration) were observed at 0.48% Pb-CVO. Larval and pupal durations increased in all treatment concentrations (0.25, 0.3, 0.4 and 0.5%) whereas, pupal weight decreased compared to control. Adult longevity of S. litura was reduced in all treatments but predominantly in the 0.4 and 0.5% Pb-CVO. Correspondingly, mean fecundity rate was reduced at all concentrations compared to control. Histological studies of larvae mid-gut profiles of S. litura were severely damaged in 1.0 and 1.5% and showed abnormalities in mid-gut cells with 0.25 and 0.5% Pb-CVO treatments. Earthworm toxicity illustrated that 0.1% of chemical insecticides (monocrotophos and cypermethrin) varied widely in their contact toxicities compared to 0.5 and 1.0% Pb-CVO and control in both contact filter paper and artificial soil test. These findings suggest that twenty essential compounds of betel leaf oil were significant inhibitors of the development and caused behavioral changes of S. litura. Treatment with betel leaf oil at these concentrations had no adverse effect on earthworm populations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Heterogeneous Photochemistry of Agrochemicals at the Leaf Surface: A Case Study of Plant Activator Acibenzolar-S-methyl.

PubMed

Sleiman, M; de Sainte Claire, P; Richard, C

2017-09-06

The photoreactivity of plant activator benzo(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester (BTH), commonly named acibenzolar-S-methyl, was studied on the surfaces of glass, paraffinic wax films, and apple leaves. Experiments were carried out in a solar simulator using pure and formulated BTH (BION). Surface photoproducts were identified using liquid chromatography coupled with electrospray ionization and high-resolution Orbitrap mass spectrometry, while volatile photoproducts were characterized using an online thermal desorption system coupled to a gas chromatography-mass spectrometry (GC-MS) system. Pure BTH degraded quickly on wax surfaces with a half-life of 5.0 ± 0.5 h, whereas photolysis of formulated BTH was 7 times slower (t 1/2 = 36 ± 14 h). On the other hand, formulated BTH was found to photolyze quickly on detached apple leaves with a half-life of 2.8 h ± 0.4 h. This drastic difference in photoreactivity was attributed to the nature and spreading of the BTH deposit, as influenced by the surfactant and surface characteristics. Abiotic stress of irradiated apple leaf was also shown to produce OH radicals which might contribute to the enhanced photodegradability. Eight surface photoproducts were identified, whereas GC-MS analyses revealed the formation of gaseous dimethyl disulfide and methanethiol. The yield of dimethyl disulfide ranged between 1.5% and 12%, and a significant fraction of dimethyl disulfide produced was found to be absorbed by the leaf. This is the first study to report on the formation of volatile chemicals and OH radicals during agrochemical photolysis on plant surfaces. The developed experimental approach can provide valuable insights into the heterogeneous photoreactivity of sprayed agrochemicals and could help improve dissipation models.

Plant architecture and prey distribution influence foraging behavior of the predatory mite Phytoseiulus persimilis (Acari: Phytoseiidae).

PubMed

Gontijo, Lessando M; Nechols, James R; Margolies, David C; Cloyd, Raymond A

2012-01-01

The arrangement, number, and size of plant parts may influence predator foraging behavior, either directly, by altering the rate or pattern of predator movement, or, indirectly, by affecting the distribution and abundance of prey. We report on the effects of both plant architecture and prey distribution on foraging by the predatory mite, Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae), on cucumber (Cucumis sativus L.). Plants differed in leaf number (2- or 6-leafed), and there were associated differences in leaf size, plant height, and relative proportions of plant parts; but all had the same total surface area. The prey, the twospotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae), were distributed either on the basal leaf or on all leaves. The effect of plant architecture on predator foraging behavior varied depending on prey distribution. The dimensions of individual plant parts affected time allocated to moving and feeding, but they did not appear to influence the frequency with which predators moved among different plant parts. Overall, P. persimilis moved less, and fed upon prey longer, on 6-leafed plants with prey on all leaves than on plants representing other treatment combinations. Our findings suggest that both plant architecture and pattern of prey distribution should be considered, along with other factors such as herbivore-induced plant volatiles, in augmentative biological control programs.

The Chloroplast-Localized Phospholipases D α4 and α5 Regulate Herbivore-Induced Direct and Indirect Defenses in Rice1[C][W

PubMed Central

Qi, Jinfeng; Zhou, Guoxin; Yang, Lijuan; Erb, Matthias; Lu, Yanhua; Sun, Xiaoling; Cheng, Jiaan; Lou, Yonggen

2011-01-01

The oxylipin pathway is of central importance for plant defensive responses. Yet, the first step of the pathway, the liberation of linolenic acid following induction, is poorly understood. Phospholipases D (PLDs) have been hypothesized to mediate this process, but data from Arabidopsis (Arabidopsis thaliana) regarding the role of PLDs in plant resistance have remained controversial. Here, we cloned two chloroplast-localized PLD genes from rice (Oryza sativa), OsPLDα4 and OsPLDα5, both of which were up-regulated in response to feeding by the rice striped stem borer (SSB) Chilo suppressalis, mechanical wounding, and treatment with jasmonic acid (JA). Antisense expression of OsPLDα4 and -α5 (as-pld), which resulted in a 50% reduction of the expression of the two genes, reduced elicited levels of linolenic acid, JA, green leaf volatiles, and ethylene and attenuated the SSB-induced expression of a mitogen-activated protein kinase (OsMPK3), a lipoxygenase (OsHI-LOX), a hydroperoxide lyase (OsHPL3), as well as a 1-aminocyclopropane-1-carboxylic acid synthase (OsACS2). The impaired oxylipin and ethylene signaling in as-pld plants decreased the levels of herbivore-induced trypsin protease inhibitors and volatiles, improved the performance of SSB and the rice brown planthopper Nilaparvata lugens, and reduced the attractiveness of plants to a larval parasitoid of SSB, Apanteles chilonis. The production of trypsin protease inhibitors in as-pld plants could be partially restored by JA, while the resistance to rice brown planthopper and SSB was restored by green leaf volatile application. Our results show that phospholipases function as important components of herbivore-induced direct and indirect defenses in rice. PMID:21984727

The chloroplast-localized phospholipases D α4 and α5 regulate herbivore-induced direct and indirect defenses in rice.

PubMed

Qi, Jinfeng; Zhou, Guoxin; Yang, Lijuan; Erb, Matthias; Lu, Yanhua; Sun, Xiaoling; Cheng, Jiaan; Lou, Yonggen

2011-12-01

The oxylipin pathway is of central importance for plant defensive responses. Yet, the first step of the pathway, the liberation of linolenic acid following induction, is poorly understood. Phospholipases D (PLDs) have been hypothesized to mediate this process, but data from Arabidopsis (Arabidopsis thaliana) regarding the role of PLDs in plant resistance have remained controversial. Here, we cloned two chloroplast-localized PLD genes from rice (Oryza sativa), OsPLDα4 and OsPLDα5, both of which were up-regulated in response to feeding by the rice striped stem borer (SSB) Chilo suppressalis, mechanical wounding, and treatment with jasmonic acid (JA). Antisense expression of OsPLDα4 and -α5 (as-pld), which resulted in a 50% reduction of the expression of the two genes, reduced elicited levels of linolenic acid, JA, green leaf volatiles, and ethylene and attenuated the SSB-induced expression of a mitogen-activated protein kinase (OsMPK3), a lipoxygenase (OsHI-LOX), a hydroperoxide lyase (OsHPL3), as well as a 1-aminocyclopropane-1-carboxylic acid synthase (OsACS2). The impaired oxylipin and ethylene signaling in as-pld plants decreased the levels of herbivore-induced trypsin protease inhibitors and volatiles, improved the performance of SSB and the rice brown planthopper Nilaparvata lugens, and reduced the attractiveness of plants to a larval parasitoid of SSB, Apanteles chilonis. The production of trypsin protease inhibitors in as-pld plants could be partially restored by JA, while the resistance to rice brown planthopper and SSB was restored by green leaf volatile application. Our results show that phospholipases function as important components of herbivore-induced direct and indirect defenses in rice.

Large drought-induced variations in oak leaf volatile organic compound emissions during PINOT NOIR 2012.

PubMed

Geron, Chris; Daly, Ryan; Harley, Peter; Rasmussen, Rei; Seco, Roger; Guenther, Alex; Karl, Thomas; Gu, Lianhong

2016-03-01

Leaf-level isoprene and monoterpene emissions were collected and analyzed from five of the most abundant oak (Quercus) species in Central Missouri's Ozarks Region in 2012 during PINOT NOIR (Particle Investigations at a Northern Ozarks Tower - NOx, Oxidants, Isoprene Research). June measurements, prior to the onset of severe drought, showed isoprene emission rates and leaf temperature responses similar to those previously reported in the literature and used in Biogenic Volatile Organic Compound (BVOC) emission models. During the peak of the drought in August, isoprene emission rates were substantially reduced, and response to temperature was dramatically altered, especially for the species in the red oak subgenus (Erythrobalanus). Quercus stellata (in the white oak subgenus Leucobalanus), on the other hand, increased its isoprene emission rate during August, and showed no decline at high temperatures during June or August, consistent with its high tolerance to drought and adaptation to xeric sites at the prairie-deciduous forest interface. Mid-late October measurements were conducted after soil moisture recharge, but were affected by senescence and cooler temperatures. Isoprene emission rates were considerably lower from all species compared to June and August data. The large differences between the oaks in response to drought emphasizes the need to consider BVOC emissions at the species level instead of just the whole canopy. Monoterpene emissions from Quercus rubra in limited data were highest among the oaks studied, while monoterpene emissions from the other oak species were 80-95% lower and less than assumed in current BVOC emission models. Major monoterpenes from Q. rubra (and in ambient air) were p-cymene, α-pinene, β-pinene, d-limonene, γ-terpinene, β-ocimene (predominantly1,3,7-trans-β-ocimene, but also 1,3,6-trans-β-ocimene), tricyclene, α-terpinene, sabinene, terpinolene, and myrcene. Results are discussed in the context of canopy flux studies conducted at the site during PINOT NOIR, which are described elsewhere. The leaf isoprene emissions before and during the drought were consistent with above canopy fluxes, while leaf and branch monoterpene emissions were an order of magnitude lower than the observed above canopy fluxes, implying that other sources may be contributing substantially to monoterpene fluxes at this site. This strongly demonstrates the need for further simultaneous canopy and enclosure BVOC emission studies. Published by Elsevier Ltd.

Measurement of Leaf Mass and Leaf Area of Oaks In A Mediterranean-climate Region For Biogenic Emission Estimation

NASA Astrophysics Data System (ADS)

Karlik, J.

Given the key role played by biogenic volatile organic compounds (BVOC) in tro- pospheric chemistry and regional air quality, it is critical to generate accurate BVOC emission inventories. Because several oak species have high BVOC emission rates, and oak trees are often of large stature with corresponding large leaf masses, oaks may be the most important genus of woody plants for BVOC emissions modeling in the natural landscapes of Mediterranean-climate regions. In California, BVOC emis- sions from oaks may mix with anthropogenic emissions from urban areas, leading to elevated levels of ozone. Data for leaf mass and leaf area for a stand of native blue oaks (Quercus douglasii) were obtained through harvest and leaf removal from 14 trees lo- cated in the Sierra Nevada foothills of central California. Trees ranged in height from 4.2 to 9.9 m, with trunk diameters at breast height of 14 to 85 cm. Mean leaf mass density was 730 g m-2 for the trees and had an overall value of 310 g m-2 for the site. Consideration of the surrounding grassland devoid of trees resulted in a value of about 150 g m-2, less than half of reported values for eastern U.S. oak woodlands, but close to a reported value for oaks found in St. Quercio, Italy. The mean value for leaf area index (LAI) for the trees at this site was 4.4 m2 m-2. LAI for the site was 1.8 m2 m-2, but this value was appropriate for the oak grove only; including the surrounding open grassland resulted in an overall LAI value of 0.9 m2 m-2 or less. A volumetric method worked well for estimating the leaf mass of the oak trees. Among allometric relationships investigated, trunk circumference, mean crown radius, and crown projec- tion were well correlated with leaf mass. Estimated emission of isoprene (mg C m-2 h-1) for the site based these leaf mass data and experimentally determined emission rate was similar to that reported for a Mediterranean oak woodland in France.

Composition of the volatile fraction of a sample of Brazilian green propolic and its phytotoxic activity.

PubMed

Fernandes-Silva, Caroline C; Lima, Carolina A; Negri, Giuseppina; Salatino, Maria L F; Salatino, Antonio; Mayworm, Marco A S

2015-12-01

Propolis is a resinous material produced by honeybees, containing mainly beeswax and plant material. Despite the wide spectrum of biological activity of propolis, to our knowledge no studies have been carried out about phytotoxic properties of Brazilian propolis and its constituents. The aims of this study were to analyze the chemical composition and to evaluate the phytotoxic activity of the volatile fraction of a sample of Brazilian green propolis. Main constituents are the phenylpropanoid 3-prenylcinnamic acid allyl ester (26.3%) and the sesquiterpene spathulenol (23.4%). Several other sesquiterpenes and phenylpropanoids, in addition to linalool and α-terpineol (monoterpenes), were also detected. The activity of solutions of the volatile fraction at 1.0, 0.5 and 0.1% was tested on lettuce seeds and seedlings. The solution at 1% inhibited completely the seed germination and solutions at 0.1 and 0.5% reduced the germination rate index. The solution at 0.5% reduced the growth of the hypocotyl-radicle axis and the development of the cotyledon leaf. The chemical composition of the volatile fraction of this Brazilian green propolis is different from those previously described, and these results may contribute to a better understanding about the chemical variations in propolis. The volatile fraction of Brazilian green propolis influences both germination of seed lettuce and the growth of its seedlings, showing an phytotoxic potential. © 2014 Society of Chemical Industry.

Comparative Analysis of the Volatile Components of Agrimonia eupatoria from Leaves and Roots by Gas Chromatography-Mass Spectrometry and Multivariate Curve Resolution

PubMed Central

Feng, Xiao-Liang; He, Yun-biao; Liang, Yi-Zeng; Wang, Yu-Lin; Huang, Lan-Fang; Xie, Jian-Wei

2013-01-01

Gas chromatography-mass spectrometry and multivariate curve resolution were applied to the differential analysis of the volatile components in Agrimonia eupatoria specimens from different plant parts. After extracted with water distillation method, the volatile components in Agrimonia eupatoria from leaves and roots were detected by GC-MS. Then the qualitative and quantitative analysis of the volatile components in the main root of Agrimonia eupatoria was completed with the help of subwindow factor analysis resolving two-dimensional original data into mass spectra and chromatograms. 68 of 87 separated constituents in the total ion chromatogram of the volatile components were identified and quantified, accounting for about 87.03% of the total content. Then, the common peaks in leaf were extracted with orthogonal projection resolution method. Among the components determined, there were 52 components coexisting in the studied samples although the relative content of each component showed difference to some extent. The results showed a fair consistency in their GC-MS fingerprint. It was the first time to apply orthogonal projection method to compare different plant parts of Agrimonia eupatoria, and it reduced the burden of qualitative analysis as well as the subjectivity. The obtained results proved the combined approach powerful for the analysis of complex Agrimonia eupatoria samples. The developed method can be used to further study and quality control of Agrimonia eupatoria. PMID:24286016

Comparative Analysis of the Volatile Components of Agrimonia eupatoria from Leaves and Roots by Gas Chromatography-Mass Spectrometry and Multivariate Curve Resolution.

PubMed

Feng, Xiao-Liang; He, Yun-Biao; Liang, Yi-Zeng; Wang, Yu-Lin; Huang, Lan-Fang; Xie, Jian-Wei

2013-01-01

Gas chromatography-mass spectrometry and multivariate curve resolution were applied to the differential analysis of the volatile components in Agrimonia eupatoria specimens from different plant parts. After extracted with water distillation method, the volatile components in Agrimonia eupatoria from leaves and roots were detected by GC-MS. Then the qualitative and quantitative analysis of the volatile components in the main root of Agrimonia eupatoria was completed with the help of subwindow factor analysis resolving two-dimensional original data into mass spectra and chromatograms. 68 of 87 separated constituents in the total ion chromatogram of the volatile components were identified and quantified, accounting for about 87.03% of the total content. Then, the common peaks in leaf were extracted with orthogonal projection resolution method. Among the components determined, there were 52 components coexisting in the studied samples although the relative content of each component showed difference to some extent. The results showed a fair consistency in their GC-MS fingerprint. It was the first time to apply orthogonal projection method to compare different plant parts of Agrimonia eupatoria, and it reduced the burden of qualitative analysis as well as the subjectivity. The obtained results proved the combined approach powerful for the analysis of complex Agrimonia eupatoria samples. The developed method can be used to further study and quality control of Agrimonia eupatoria.

Comparison of male and female emerald ash borer (Coleoptera: Buprestidae) responses to phoebe oil and (Z)-3-hexanol lures in light green prism traps

Treesearch

Gary G. Grant; Therese M. Poland; Tina Ciaramitaro; D. Barry Lyons; Gene C. Jones

2011-01-01

We conducted trapping experiments for the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) in Michigan, USA, and Ontario, Canada, to compare unbaited light green sticky prism traps with traps baited with phoebe oil, (Z)-3-hexenol (Z3-6:OH), or blends of other green leaf volatiles (GLVs) with Z3-6:OH. Traps were placed in the...

Sagebrush and grasshopper responses to atmospheric carbon dioxide concentration.

PubMed

Johnson, R H; Lincoln, D E

1990-08-01

Seed- and clonally-propagated plants of Big Sagebrush (Artemisia tridentata var.tridentata) were grown under atmospheric carbon dioxide regimes of 270, 350 and 650 μl l -1 and fed toMelanoplus differentialis andM. sanguinipes grasshoppers. Total shrub biomass significantly increased as carbon dioxide levels increased, as did the weight and area of individual leaves. Plants grown from seed collected in a single population exhibited a 3-5 fold variation in the concentration of leaf volatile mono- and sesquiterpenes, guaianolide sesquiterpene lactones, coumarins and flavones within each CO 2 treatment. The concentration of leaf allelochemicals did not differ significantly among CO 2 treatments for these seed-propagated plants. Further, when genotypic variation was controlled by vegetative propagation, allelochemical concentrations also did not differ among carbon dioxide treatments. On the other hand, overall leaf nitrogen concentration declined significantly with elevated CO 2 . Carbon accumulation was seen to dilute leaf nitrogen as the balance of leaf carbon versus nitrogen progressively increased as CO 2 growth concentration increased. Grasshopper feeding was highest on sagebrush leaves grown under 270 and 650 μl l -1 CO 2 , but varied widely within treatments. Leaf nitrogen concentration was an important positive factor in grasshopper relative growth but had no overall effect on consumption. Potential compensatory consumption by these generalist grasshoppers was apparently limited by the sagebrush allelochemicals. Insects with a greater ability to feed on chemically defended host plants under carbon dioxide enrichment may ultimately consume leaves with a lower nitrogen concentration but the same concentration of allelochemicals. Compensatory feeding may potentially increase the amount of dietary allelochemicals ingested for each unit of nitrogen consumed.

Emission of Volatile Compounds from Apple Plants Infested with Pandemis heparana Larvae, Antennal Response of Conspecific Adults, and Preliminary Field Trial.

PubMed

Giacomuzzi, Valentino; Cappellin, Luca; Khomenko, Iuliia; Biasioli, Franco; Schütz, Stefan; Tasin, Marco; Knight, Alan L; Angeli, Sergio

2016-12-01

This study investigated the volatile emission from apple (Malus x domestica Borkh., cv. Golden Delicious) foliage that was either intact, mechanically-damaged, or exposed to larval feeding by Pandemis heparana (Denis and Schiffermüller) (Lepidoptera: Tortricidae). Volatiles were collected by closed-loop-stripping-analysis and characterized by gas chromatography-mass spectrometry in three time periods: after 1 h and again 24 and 48 h later. Volatiles for all treatments also were monitored continuously over a 72-h period by the use of proton transfer reaction - time of flight-mass spectrometry (PTR-ToF-MS). In addition, the volatile samples were analyzed by gas chromatography-electroantennographic detection (GC-EAD) using male and female antennae of P. heparana. Twelve compounds were detected from intact foliage compared with 23 from mechanically-damaged, and 30 from P. heparana-infested foliage. Interestingly, six compounds were released only by P. heparana-infested foliage. The emission dynamics of many compounds measured by PTR-ToF-MS showed striking differences according to the timing of herbivory and the circadian cycle. For example, the emission of green leaf volatiles began shortly after the start of herbivory, and increased over time independently from the light-dark cycle. Conversely, the emission of terpenes and aromatic compounds showed a several-hour delay in response to herbivory, and followed a diurnal rhythm. Methanol was the only identified volatile showing a nocturnal rhythm. Consistent GC-EAD responses were found for sixteen compounds, including five aromatic ones. A field trial in Sweden demonstrated that benzyl alcohol, 2-phenylethanol, phenylacetonitrile, and indole lures placed in traps were not attractive to Pandemis spp. adults, but 2-phenylethanol and phenylacetonitrile when used in combination with acetic acid were attractive to both sexes.

Combined Effects of Early Season Leaf Removal and Climatic Conditions on Aroma Precursors in Sauvignon Blanc Grapes.

PubMed

Sivilotti, Paolo; Falchi, Rachele; Herrera, Jose Carlos; Škvarč, Branka; Butinar, Lorena; Sternad Lemut, Melita; Bubola, Marijan; Sabbatini, Paolo; Lisjak, Klemen; Vanzo, Andreja

2017-09-27

Early leaf removal around the cluster zone is a common technique applied in cool climate viticulture, to regulate yield components and improve fruit quality. Despite the increasing amount of information on early leaf removal and its impact on total soluble solids, anthocyanins, and polyphenols, less is known regarding aroma compounds. In order to verify the hypothesis that defoliation, applied before or after flowering, could impact the biosynthesis of thiol precursors, we performed a two year (2013 and 2014) experiment on Sauvignon blanc. We provided evidence that differential accumulation of thiol precursors in berries is affected by the timing of defoliation, and this impact was related to modifications in the biosynthetic pathway. Furthermore, the possible interaction between leaf removal treatment and seasonal weather conditions, and its effect on the biosynthesis of volatile precursors are discussed. Our results suggested that in Sauvignon blanc the relative proportion of 4-S-glutathionyl-4-methylpentan-2-one (G-4MSP) and 3-S-glutathionylhexan-1-ol (G-3SH) precursors can be affected by defoliation, and this could be related to the induction of two specific genes encoding glutathione-S-transferases (VvGST3 and VvGST5), while no significant effects on basic fruit chemical parameters, polyphenols, and methoxypyrazines were ascertained under our experimental conditions.

Three odorant binding proteins may regulate the behavioural response of Chrysopa pallens to plant volatiles and the aphid alarm pheromone (E)-β-farnesene.

PubMed

Li, Z-Q; Zhang, S; Cai, X-M; Luo, J-Y; Dong, S-L; Cui, J-J; Chen, Z-M

2017-06-01

Artificial Chrysopa pallens release is a well-known method for suppressing aphids, but it is difficult to establish lacewing populations in the field. Understanding the functions of C. pallens odorant-binding proteins (CpalOBPs) and behavioural responses of C. pallens to plant volatiles and aphid alarm pheromone (E)-ß-farnesene has important implications for population establishment after lacewing release. Based on our previous study, five antennae-enriched CpalOBPs were selected. Sequence alignment and phylogenetic analysis revealed that these five CpalOBPs were Classic OBPs and separated into different clades. Of them, CpalOBP10 clustered in the same clade with aphid OBP7, which mediates the perception of green leaf volatiles and (E)-ß-farnesene. Ligand-binding assays showed 31 compounds, including plant-derived compounds, pest-induced volatiles and (E)-ß-farnesene, had high binding affinities for at least one of these five CpalOBPs. Of the 31 compounds, the pest-induced volatiles (Z)-3-hexenyl hexanoate and 2-hexyl-1-decanol, used in host location by the black bean aphid, elicited significant attractive behavioural responses from C. pallens. Conversely, (E)-ß-farnesene elicited strongly repellent behavioural responses. It is conceivable that C. pallens utilizes plant-derived compounds, pest-induced volatiles and (E)-ß-farnesene as foraging cues. Our studies provide new insights into the interrelationships amongst C. pallens, its prey and the host plants. Compounds that elicited significant behavioural responses from C. pallens were also identified. © 2017 The Royal Entomological Society.

Are Bacterial Volatile Compounds Poisonous Odors to a Fungal Pathogen Botrytis cinerea, Alarm Signals to Arabidopsis Seedlings for Eliciting Induced Resistance, or Both?

PubMed Central

Sharifi, Rouhallah; Ryu, Choong-Min

2016-01-01

Biological control (biocontrol) agents act on plants via numerous mechanisms, and can be used to protect plants from pathogens. Biocontrol agents can act directly as pathogen antagonists or competitors or indirectly to promote plant induced systemic resistance (ISR). Whether a biocontrol agent acts directly or indirectly depends on the specific strain and the pathosystem type. We reported previously that bacterial volatile organic compounds (VOCs) are determinants for eliciting plant ISR. Emerging data suggest that bacterial VOCs also can directly inhibit fungal and plant growth. The aim of the current study was to differentiate direct and indirect mechanisms of bacterial VOC effects against Botrytis cinerea infection of Arabidopsis. Volatile emissions from Bacillus subtilis GB03 successfully protected Arabidopsis seedlings against B. cinerea. First, we investigated the direct effects of bacterial VOCs on symptom development and different phenological stages of B. cinerea including spore germination, mycelial attachment to the leaf surface, mycelial growth, and sporulation in vitro and in planta. Volatile emissions inhibited hyphal growth in a dose-dependent manner in vitro, and interfered with fungal attachment on the hydrophobic leaf surface. Second, the optimized bacterial concentration that did not directly inhibit fungal growth successfully protected Arabidopsis from fungal infection, which indicates that bacterial VOC-elicited plant ISR has a more important role in biocontrol than direct inhibition of fungal growth on Arabidopsis. We performed qRT-PCR to investigate the priming of the defense-related genes PR1, PDF1.2, and ChiB at 0, 12, 24, and 36 h post-infection and 14 days after the start of plant exposure to bacterial VOCs. The results indicate that bacterial VOCs potentiate expression of PR1 and PDF1.2 but not ChiB, which stimulates SA- and JA-dependent signaling pathways in plant ISR and protects plants against pathogen colonization. This study provides new evidence for bacterial VOC-elicited plant ISR that protects Arabidopsis plants from infection by the necrotrophic fungus B. cinerea. Our work reveals that bacterial VOCs primarily act via an indirect mechanism to elicit plant ISR, and have a major role in biocontrol against fungal pathogens. PMID:26941721

Monoterpene emissions from Pinus halepensis forests in a semi-arid region (Israel)

NASA Astrophysics Data System (ADS)

Seco, R.; Karl, T.; Turnipseed, A. A.; Greenberg, J.; Guenther, A. B.; Llusia, J.; Penuelas, J.; Kim, S.; Dicken, U.; Rotenberg, E.; Rohatyn, S.; Preisler, Y.; Yakir, D.

2013-12-01

Atmospheric volatile organic compounds (VOCs) have key environmental and biological roles, and can affect atmospheric chemisty, secondary aerosol formation, and as a consequence also climate. At the same time, global changes in climate arising from human activities can modify the VOC emissions of vegetation in the coming years. Monoterpene emission fluxes were measured during April 2013 at two forests in the semi-arid climate of Israel. Both forests were dominated by the same pine species, Pinus halepensis, but differed in the amount of annual average precipitation received (280 and 800 mm at Yatir and Birya, respectively). Measurements performed included leaf-level sampling as well as canopy-level flux calculations. Leaf level monoterpene emissions were sampled from leaf cuvettes with adsorbent cartridges and later analyzed by GC-MS. Canopy scale fluxes were calculated with the Disjunct Eddy Covariance technique by means of a Quadrupole PTRMS. We report the differences observed between the two forests in terms of photosynthetic activity and monoterpene emissions, aiming to see the effect of the different precipitation regimes at each location.

The future of isoprene emission from leaves, canopies and landscapes.

PubMed

Sharkey, Thomas D; Monson, Russell K

2014-08-01

Isoprene emission from plants plays a dominant role in atmospheric chemistry. Predicting how isoprene emission may change in the future will help predict changes in atmospheric oxidant, greenhouse gas and secondary organic aerosol concentrations in the future atmosphere. At the leaf-scale, an increase in isoprene emission with increasing temperature is offset by a reduction in isoprene emission rate caused by increased CO₂. At the canopy scale, increased leaf area index in elevated CO₂ can offset the reduction in leaf-scale isoprene emission caused by elevated CO₂. At the landscape scale, a reduction in forest coverage may decrease, while forest fertilization and community composition dynamics are likely to cause an increase in the global isoprene emission rate. Here we review the potential for changes in the isoprene emission rate at all of these scales. When considered together, it is likely that these interacting effects will result in an increase in the emission of the most abundant plant volatile, isoprene, from the biosphere to the atmosphere in the future. © 2014 John Wiley & Sons Ltd.

Phylloremediation of Air Pollutants: Exploiting the Potential of Plant Leaves and Leaf-Associated Microbes

PubMed Central

Wei, Xiangying; Lyu, Shiheng; Yu, Ying; Wang, Zonghua; Liu, Hong; Pan, Dongming; Chen, Jianjun

2017-01-01

Air pollution is air contaminated by anthropogenic or naturally occurring substances in high concentrations for a prolonged time, resulting in adverse effects on human comfort and health as well as on ecosystems. Major air pollutants include particulate matters (PMs), ground-level ozone (O3), sulfur dioxide (SO2), nitrogen dioxides (NO2), and volatile organic compounds (VOCs). During the last three decades, air has become increasingly polluted in countries like China and India due to rapid economic growth accompanied by increased energy consumption. Various policies, regulations, and technologies have been brought together for remediation of air pollution, but the air still remains polluted. In this review, we direct attention to bioremediation of air pollutants by exploiting the potentials of plant leaves and leaf-associated microbes. The aerial surfaces of plants, particularly leaves, are estimated to sum up to 4 × 108 km2 on the earth and are also home for up to 1026 bacterial cells. Plant leaves are able to adsorb or absorb air pollutants, and habituated microbes on leaf surface and in leaves (endophytes) are reported to be able to biodegrade or transform pollutants into less or nontoxic molecules, but their potentials for air remediation has been largely unexplored. With advances in omics technologies, molecular mechanisms underlying plant leaves and leaf associated microbes in reduction of air pollutants will be deeply examined, which will provide theoretical bases for developing leaf-based remediation technologies or phylloremediation for mitigating pollutants in the air. PMID:28804491

Phylloremediation of Air Pollutants: Exploiting the Potential of Plant Leaves and Leaf-Associated Microbes.

PubMed

Wei, Xiangying; Lyu, Shiheng; Yu, Ying; Wang, Zonghua; Liu, Hong; Pan, Dongming; Chen, Jianjun

2017-01-01

Air pollution is air contaminated by anthropogenic or naturally occurring substances in high concentrations for a prolonged time, resulting in adverse effects on human comfort and health as well as on ecosystems. Major air pollutants include particulate matters (PMs), ground-level ozone (O 3 ), sulfur dioxide (SO 2 ), nitrogen dioxides (NO 2 ), and volatile organic compounds (VOCs). During the last three decades, air has become increasingly polluted in countries like China and India due to rapid economic growth accompanied by increased energy consumption. Various policies, regulations, and technologies have been brought together for remediation of air pollution, but the air still remains polluted. In this review, we direct attention to bioremediation of air pollutants by exploiting the potentials of plant leaves and leaf-associated microbes. The aerial surfaces of plants, particularly leaves, are estimated to sum up to 4 × 10 8 km 2 on the earth and are also home for up to 10 26 bacterial cells. Plant leaves are able to adsorb or absorb air pollutants, and habituated microbes on leaf surface and in leaves (endophytes) are reported to be able to biodegrade or transform pollutants into less or nontoxic molecules, but their potentials for air remediation has been largely unexplored. With advances in omics technologies, molecular mechanisms underlying plant leaves and leaf associated microbes in reduction of air pollutants will be deeply examined, which will provide theoretical bases for developing leaf-based remediation technologies or phylloremediation for mitigating pollutants in the air.

Diffusible and Volatile Antifungal Compounds Produced by an Antagonistic Bacillus velezensis G341 against Various Phytopathogenic Fungi.

PubMed

Lim, Seong Mi; Yoon, Mi-Young; Choi, Gyung Ja; Choi, Yong Ho; Jang, Kyoung Soo; Shin, Teak Soo; Park, Hae Woong; Yu, Nan Hee; Kim, Young Ho; Kim, Jin-Cheol

2017-10-01

The aim of this study was to identify volatile and agar-diffusible antifungal metabolites produced by Bacillus sp. G341 with strong antifungal activity against various phytopathogenic fungi. Strain G341 isolated from four-year-old roots of Korean ginseng with rot symptoms was identified as Bacillus velezensis based on 16S rDNA and gyrA sequences. Strain G341 inhibited mycelial growth of all phytopathogenic fungi tested. In vivo experiment results revealed that n -butanol extract of fermentation broth effectively controlled the development of rice sheath blight, tomato gray mold, tomato late blight, wheat leaf rust, barley powdery mildew, and red pepper anthracnose. Two antifungal compounds were isolated from strain G341 and identified as bacillomycin L and fengycin A by MS/MS analysis. Moreover, volatile compounds emitted from strain G341 were found to be able to inhibit mycelial growth of various phytopathogenic fungi. Based on volatile compound profiles of strain G341 obtained through headspace collection and analysis on GC-MS, dimethylsulfoxide, 1-butanol, and 3-hydroxy-2-butanone (acetoin) were identified. Taken together, these results suggest that B. valezensis G341 can be used as a biocontrol agent for various plant diseases caused by phytopathogenic fungi.

Olfaction in the boll weevil,Anthonomus grandis Boh. (Coleoptera: Curculionidae): Electroantennogram studies.

PubMed

Dickens, J C

1984-12-01

Electroantennogram (EAG) techniques were utilized to measure the antennal olfactory responsiveness of adult boll weevils,Anthonomus grandis Boh. (Coleoptera: Curculionidae), to 38 odorants, including both insect and host plant (Gossypium hirsutum L.) volatiles. EAGs of both sexes were indicative of at least two receptor populations: one receptor population primarily responsive to pheromone components and related compounds, the other receptor population primarily responsive to plant odors. Similar responses to male aggregation pheromone components (i.e., compounds I, II, and III + IV) were obtained from both sexes, but females were slightly more sensitive to I. Both sexes were highly responsive to components of the "green leaf volatile complex," especially the six-carbon saturated and monounsaturated primary alcohols. Heptanal was the most active aldehyde tested. More acceptors responded to oxygenated monoterpenes than to monoterpene hydrocarbons. β-Bisabolol, the major volatile of cotton, was the most active sesquiterpene. In general, males, which are responsible for host selection and pheromone production, were more sensitive to plant odors than were females. In fact, males were as sensitive to β-bisabolol and heptanal as to aggregation pheromone components. Electrophysiological data are discussed with regard to the role of insect and host plant volatiles in host selection and aggregation behavior of the boll weevil.

Inhibitory effect of betel quid on the volatility of methyl mercaptan.

PubMed

Wang, C K; Chen, S L; Wu, M G

2001-04-01

Betel quid, a popular natural masticatory in Taiwan, is mainly composed of fresh areca fruit, Piper betle (leaf or inflorescence), and slaked lime paste. People say that halitosis disappears during betel quid chewing. In this study, the removal of mouth odor during betel quid chewing was discussed by using a model system which measured its inhibition on the volatility of methyl mercaptan. Results showed that crude extracts of betel quid (the mixture of areca fruit, Piper betle, and slaked lime paste) and extracts of the mixture of areca fruit and slaked lime paste exhibited marked effects on the volatility of methyl mercaptan, and the inhibition function increased when increasing amounts of slaked lime paste were added. The same condition (increased inhibition) was also found by replacing the slaked lime paste with alkaline salts (calcium hydroxide, potassium hydroxide, or sodium hydroxide). Areca fruit, the major ingredient of betel quid, contained abundant phenolics. However, the crude phenolic extract of areca fruit did not show any inhibitory activity on the volatility of methyl mercaptan. Great inhibitory activity occurred only when the crude phenolic extract of areca fruit was treated with alkali. Further studies by using gel filtration determined that the effect probably came from the oxidative polymerization of phenolics of areca fruit after alkaline treatment.

Effects of warming on groundwater flow in mountainous snowmelt-dominated catchments

NASA Astrophysics Data System (ADS)

Evans, S. G.; Ge, S.; Molotch, N. P.

2015-12-01

In mountainous regions, warmer air temperatures have led to an earlier onset of spring snowmelt and lower snowmelt rates; i.e. because snowmelt has shifted earlier when energy availability is lower. These changes to snowmelt will likely affect the partitioning of snowmelt water between surface runoff and groundwater flow, and therefore, the lag time between snowmelt and streamflow. While the connection between snowmelt and surface runoff has been well-studied, the impact of snowmelt variability on groundwater flow processes has received limited attention, especially in mountainous catchments. We construct a two-dimensional, finite element, coupled flow and heat transport hydrogeologic model to evaluate how changes in snowmelt onset and rate may alter groundwater discharge to streams in mountainous catchments. The coupled hydrogeologic model simulates seasonally frozen ground by incorporating permeability variation as a function of temperature and allows for modeling of pore water freeze and thaw. We apply the model to the Green Lakes Valley (GLV) watershed in the Rocky Mountains of Colorado, a representative snowmelt-dominated catchment. Snowmelt for the GLV catchment is reconstructed from a 12 year (1996-2007) dataset of hydrometeorological records and satellite-derived snow covered area. Modeling results suggest that on a yearly cycle, groundwater infiltration and discharge is limited by the seasonally frozen subsurface. Under average conditions from 1996 to 2007, maximum groundwater discharge to the surface lags maximum snowmelt by approximately two months. Ongoing modeling is exploring how increasing air temperatures affect lag times between snowmelt and groundwater discharge to streams. This study has implications for water resource availability and its temporal variability in a warming global climate.

Evaluation of the Ganglion Cell Complex and Retinal Nerve Fiber Layer in Low, Moderate, and High Myopia: A Study by RTVue Spectral Domain Optical Coherence Tomography.

PubMed

Sezgin Akcay, Betul Ilkay; Gunay, Betul Onal; Kardes, Esra; Unlu, Cihan; Ergin, Ahmet

2017-01-01

To assess the effect of low, moderate, and high myopia on the thickness of the retinal nerve fiber layer (RNFL) and Ganglion cell complex (GCC) measured by Spectral Domain Optical Coherence Tomography (SD-OCT) in non-glaucomatous subjects. The subjects were divided into three groups: low (n = 81, 35.6%), moderate (n = 79, 34.8%), and highly myopic eyes (n = 67, 29.5%). The RNFL thickness profile, including the average, superior, nasal, inferior, and temporal quadrant and each of the eight directional thicknesses, was measured. GCC parameters, including the average, superior, and inferior values, the focal loss volume (FLV), and the global loss volume (GLV), were measured. The correlation between the OCT measurements and the axial length was evaluated. The average, superior, inferior, and nasal RNFL thicknesses of low and moderate myopic eyes were found to be significantly higher than those of highly myopic eyes. The temporal RNFL thicknesses were not different among the three groups. The average, superior, and inferior ganglion cell complex values of low and moderate myopic eyes were significantly higher than those of highly myopic eyes. The FLV and GLV of low and moderate myopic eyes were significantly higher than those of highly myopic eyes (p = 0.001 for all). In the moderate and high myopia groups, the average RNFL thickness and GCC thickness were both negatively correlated with the axial length. Highly myopic subjects tend to have thinner RNFL and GCC thicknesses than subjects with low and moderate myopia.

VOC emission into the atmosphere by trees and leaf litter in Polish forests

NASA Astrophysics Data System (ADS)

Isidorov, V.; Smolewska, M.; Tyszkiewicz, Z.

2009-04-01

It is generally recognized at present that the vegetation of continents is the principal source of reactive volatile organic compounds (VOC) of the atmosphere. The upper limit of the evaluation of global phytogenic VOC is 1100-1500 Tg/yr (Isidorov, 1990; Guenther et al., 1995). Although these global evaluations showing the place of phytogenic emission among of other VOC sources are important, evaluations for individual countries are also very important. This poster represents the results of the estimation of VOC emission from Polish forests. Calculations took into account the composition and age of forests. According to our estimation, the total VOC emission by the arboreal vegetation differs from 190 to 750 kt/yr, depending of weather conditions in different years. There are only few studies conducted on decaying plant material as a source of atmospheric VOCs, but still they are able to give evidence of the importance of this source. For Polish forests, the litter mass is estimated to be (16-19)106 t/yr. These organic materials undergo decomposition by mesofauna and microorganisms. In these processes volatile organic compounds (VOC) stored in the litter and secondary metabolites of litter-destroying fungi are emitted into the atmosphere. The scale of the phenomenon makes leaf litter an important VOC source in the atmosphere. The filling of numerous gaps in researches of VOC emissions from decomposing leaf litter demands carrying out of long term field experiments in various climatic conditions. In this communication we report also the results of 3.5-year experiment on qualitative and quantitative GC-MS investigations of VOC emitted into the gas phase from leaves litter of some species of deciduous and coniferous trees of Polish forests. Apart from terpenes and their oxygenated derivatives, which are usual in plant tissues, leaf litter intensively emits vast amounts of lower alcohols and carbonyl compounds. We suppose that these volatile substances are products of vital activity of fungi which decompose leaf litter. Verification of the hypothesis was carried out in the frames of a long-term experiment on decomposition of Scots pine and common spruce litter. The experiment was conducted in natural conditions by placing litter bags on undisturbed topsoil in a forest area where pine and spruce trees prevailed. Part of the needles placed were taken out of the litter bags on the 30th, 282nd, 490th, 630th and 920th day of the experiment for subsequent isolation of fungi which colonize the litter (overall there were identified 98 species which belong to 48 genera of fungi). The experiment revealed that species composition of the fungi colonizing pine and spruce litter varies considerably. At the early stages of decomposition, dematiceous hypnomycetes, which belongs to Cladosporum, Alternaria genera as well as Hormonem genus, capable of utilizing pectin, were dominant species. At the later stages they were substituted with phycomycetes (Mucor sp.), ascomycetes (Penicillium sp.) and basidiomycetes (Trichderma sp.), the most significant group of "secondary saprophytes" able to carry out biodegradation of polysaccharides and lignin. In volatile emissions of all the 15 species of fungi there were identified 80 VOCs of different classes: terpene hydrocarbons and their oxygenated derivatives, C6-C14 aliphatic and C6-C10 aromatic hydrocarbons, C1-C8 alcohols, C2-C9 carbonyls, esters, furans, and halocarbons. VOC composition was specific for each fungi species and depended on the litter of a particular tree species from which it had been isolated. For instance, the emission rate of terpenes, alcohols and carbonyl compounds by Trichoderma polysporum isolated from pine and spruce litter was 3-5 times different. Differences in composition of VOCs emitted into the gas phase by "primary" and "secondary" fungi species which colonize pine and spruce litter are also discussed. This work was supported by Grant MNiSW N305 067 32/2411.

Herbivore-induced volatiles in the perennial shrub, Vaccinium corymbosum, and their role in inter-branch signaling.

PubMed

Rodriguez-Saona, Cesar R; Rodriguez-Saona, Luis E; Frost, Christopher J

2009-02-01

Herbivore feeding activates plant defenses at the site of damage as well as systemically. Systemic defenses can be induced internally by signals transported via phloem or xylem, or externally transmitted by volatiles emitted from the damaged tissues. We investigated the role of herbivore-induced plant volatiles (HIPVs) in activating a defense response between branches in blueberry plants. Blueberries are perennial shrubs that grow by initiating adventitious shoots from a basal crown, which produce new lateral branches. This type of growth constrains vascular connections between shoots and branches within plants. While we found that leaves within a branch were highly connected, vascular connectivity was limited between branches within shoots and absent between branches from different shoots. Larval feeding by gypsy moth, exogenous methyl jasmonate, and mechanical damage differentially induced volatile emissions in blueberry plants, and there was a positive correlation between amount of insect damage and volatile emission rates. Herbivore damage did not affect systemic defense induction when we isolated systemic branches from external exposure to HIPVs. Thus, internal signals were not capable of triggering systemic defenses among branches. However, exposure of branches to HIPVs from an adjacent branch decreased larval consumption by 70% compared to those exposed to volatiles from undamaged branches. This reduction in leaf consumption did not result in decreased volatile emissions, indicating that leaves became more responsive to herbivory (or "primed") after being exposed to HIPVs. Chemical profiles of leaves damaged by gypsy moth caterpillars, exposed to HIPVs, or non-damaged controls revealed that HIPV-exposed leaves had greater chemical similarities to damaged leaves than to control leaves. Insect-damaged leaves and young HIPV-exposed leaves had higher amounts of endogenous cis-jasmonic acid compared to undamaged and non-exposed leaves, respectively. Our results show that exposure to HIPVs triggered systemic induction of direct defenses against gypsy moth and primed volatile emissions, which can be an indirect defense. Blueberry plants appear to rely on HIPVs as external signals for inter-branch communication.

Modelling bioaccumulation of semi-volatile organic compounds (SOCs) from air in plants based on allometric principles.

PubMed

Steyaert, Nils L L; Hauck, Mara; Van Hulle, Stijn W H; Hendriks, A Jan

2009-10-01

A model was developed for gaseous plant-air exchange of semi-volatile organic compounds. Based on previous soil-plant modelling, uptake and elimination kinetics were scaled as a function of plant mass and octanol-air partition ratios. Exchange of chemicals was assumed to be limited by resistances encountered during diffusion through a laminar boundary layer of air and permeation through the cuticle of the leaf. The uptake rate constant increased and the elimination rate constant decreased with the octanol-air partition ratio both apparently levelling off at high values. Differences in kinetics between species could be explained by their masses. Validation on independent data showed that bio-concentration factors of PCBs, chlorobenzenes and other chemicals were predicted well by the model. For pesticides, polycyclic aromatic hydrocarbons and dioxins deviations occurred.

HS/GC-MS analyzed chemical composition of the aroma of fruiting bodies of two species of genus Lentinus (Higher Basidiomycetes).

PubMed

Mata, Gerardo; Valdez, Karina; Mendoza, Remedios; Trigos, Ángel

2014-01-01

The chemical composition of the aroma of fresh fruiting bodies of the cultivated mushroom Lentinus boryanus is described here and compared with medicinal shiitake mushroom L. edodes. Volatile compounds were analyzed through headspace sampling coupled with gas chromatography-mass spectrometry. The mushrooms under study were grown on different substrates based on barley straw, sugarcane bagasse, oak wood sawdust, and beech leaf litter. It was determined that L. boryanus as well as L. edodes contain an abundant amount of a volatile compound identified as 3-octanone with a sweet fruity aroma. On the other hand, only L. boryanus produced 3-octanol a characteristic aroma of cod liver oil. In total, 10 aromatic compounds were identified, some of which were obtained exclusively in one species or substrate.

Triticale crisp bread enriched with selected bioactive additives: volatile profile, physical characteristics, sensory and nutritional properties.

PubMed

Makowska, Agnieszka; Majcher, Małgorzata; Mildner-Szkudlarz, Sylwia; Jedrusek-Golinska, Anna; Przygoński, Krzysztof

2017-09-01

The effect of selected plant additives (couch grass, artichoke, kale, nettle, ground buckwheat husks, broad beans, fenugreek seeds, and extracts of yellow tea and mulberry leaf) on the volatile compounds, color, texture, sensory attributes, polyphenols, and antioxidant properties of triticale crisp bread was studied. The volatile profile of control bread was dominated by lipid oxidation products with hexanal and (E)-2-nonenal predominant. The additives strongly modified the volatile profile of the extruded crisp bread. The greatest differences were recorded in the case of products with artichoke and kale additions, which had respectively about 12 and 8 times higher levels of total volatile compounds than the control crisp bread. The samples containing kale, buckwheat, and fenugreek as well as yellow tea extract characterized high levels of sulfur compounds, with methanethiol predominant. The additives, especially kale, nettle, and artichoke affected the color of the crisp breads, in most cases making them darker. In terms of texture only the crisp bread with addition of buckwheat husk was significantly harder than the control sample. On the basis of sensory evaluation it was stated that among all the additives, the artichoke and fenugreek resulted in dramatic deterioration in the extruded product taste. The used additives also affected the antioxidant properties of triticale crisp bread. The greatest content of total phenolic compounds and the highest antioxidant activity were observed for the bread with yellow tea extract addition (3.5- and 6.5-fold higher, respectively, than in control sample).

Efficacy of some plant oils alone and/or combined with different insecticides on the cotton leaf-worm Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) in Egypt.

PubMed

Mesbah, H A; Mourad, A K; Rokaia, A Z M

2006-01-01

The present work was conducted to evaluate the efficiency of two essential oils ((Flax or "Linseed" and Sesame ), five volatile plant oils ( Camphor, Red basil, Rose, Menthol and Clove ), four pesticides (Methoxyfenozide; Permethrin; Profenofos and Spinosad) and their mixtures on the cotton leaf-worm Spodoptera littoralis (Boisd.). This study was also devoted to minimize the usage of conventional insecticides, reduce the environmental pollution, and protect human-beings and domestic animals from hazards due to pesticides applications. In the meantime, the delayed effect of these tested plant oils on the developing immatures and moths of the cotton leaf-worm, Spodoptera littoralis was determined. Most of the evaluated plant oils were found to have an insecticidal effect on the 4th instar larvae of the cotton leaf-worm, S. littoralis. Both the essential Sesame oil and Clove volatile oil showed rather weak toxic effect corresponding to the same concentrations and periods of the bioassay tests. Comparing the toxicity of the tested plant oils, it was affirmed that both Rose and Red basil volatile oils were the highest efficient natural phytocompounds against the treated larvae and alternatively ranked either the 1st and/or the 2nd rank, throughout the different periods of the bioassay tests, followed by the other three tested oils which were more or less efficient phytocompounds. According to the toxicity index, all the tested oils were less toxic than the superior Red basil volatile oil after 48 h. post treatment followed by the gradual decrease in toxicity of Rose, Flax and Menthol, respectively. The development of the treated 4th larval instar was blocked due to treatment with the tested plant oils. With no exception, all the efficiently tested essential and/or volatile oils acted principally as Insect Growth Inhibitors (IGIs) rather than antifeedants causing disruption of the insect development, abnormal larvae, pupae and adults that were lead finally to death. The tested mixtures of Clove and Sesame oils increased the percentage of larval mortality in comparison to their use alone against the treated 4th larval instar.Contrarily, antagonism was revealed for the mixture of Sesame/Flax oils, the calculated value of LC50 greatly increased compared to the corresponding values of their individual evaluation after 48 h. from initiating the treatment. The delayed effect of tested plant oils was inspected on certain parameters of the fitness components of the subject insect and was mainly determined for the rates of hatched eggs and emerged moths. Remarkably, the Methoxyfenozide treated 4th larval instar became passive, or ceased feeding on the treated leaves and were unable to complete normally the moulting process, which partially took place in most'of the other treated individuals. The treated larvae with the tested lower concentrations, hardly succeeded in completing moulting process. The survived larvae failed to complete the next moulting at the end of the treatments. The toxic effect of Spinosad was more apparent against the treated larvae after 72 h from application. The calculated LC50 values indicated the gradual increase of its toxic effect in the subsequent prolonged intervals of the test. Spinosad showed its activity either by contact or ingestion and caused larval characteristic symptoms. Permethrin exhibited superior toxic efficacy overall the other tested chemicals, during the period from 72 up to 96 h post treatment. The gradual increase of the toxic effect of Permethrin indicated an efficient continuous persistence of nervous toxicity. According to the specific properties of Profenofos, results revealed that the toxicity by ingestion was more potential than by contact and explained the reason of developing toxicity with the increase of bioassay inspection period. The comparative toxic efficiency of the tested insecticides proved that Permethrin was the most effective one, giving LC50 values of 2.92 and 1.53 ppm after 72 and 96 h. bioassay, respectively, followed by Profenofos, Methoxyfenozide and Spinosad, successively. In addition, the calculated values of toxicity index also proved that all the tested compounds were less toxic than Permethrin (as a standard compound ). It is worth mentioning that the combined action of the mixed pesticides with four efficient volatile plant oils showed synergistic action against the 4th larval instar of S. littoralis.

Leaf anatomy, BVOC emission and CO2 exchange of arctic plants following snow addition and summer warming.

PubMed

Schollert, Michelle; Kivimäenpää, Minna; Michelsen, Anders; Blok, Daan; Rinnan, Riikka

2017-02-01

Climate change in the Arctic is projected to increase temperature, precipitation and snowfall. This may alter leaf anatomy and gas exchange either directly or indirectly. Our aim was to assess whether increased snow depth and warming modify leaf anatomy and affect biogenic volatile organic compound (BVOC) emissions and CO 2 exchange of the widespread arctic shrubs Betula nana and Empetrum nigrum ssp. hermaphroditum METHODS: Measurements were conducted in a full-factorial field experiment in Central West Greenland, with passive summer warming by open-top chambers and snow addition using snow fences. Leaf anatomy was assessed using light microscopy and scanning electron microscopy. BVOC emissions were measured using a dynamic enclosure system and collection of BVOCs into adsorbent cartridges analysed by gas chromatography-mass spectrometry. Carbon dioxide exchange was measured using an infrared gas analyser. Despite a later snowmelt and reduced photosynthesis for B. nana especially, no apparent delays in the BVOC emissions were observed in response to snow addition. Only a few effects of the treatments were seen for the BVOC emissions, with sesquiterpenes being the most responsive compound group. Snow addition affected leaf anatomy by increasing the glandular trichome density in B. nana and modifying the mesophyll of E. hermaphroditum The open-top chambers thickened the epidermis of B. nana, while increasing the glandular trichome density and reducing the palisade:spongy mesophyll ratio in E. hermaphroditum CONCLUSIONS: Leaf anatomy was modified by both treatments already after the first winter and we suggest links between leaf anatomy, CO 2 exchange and BVOC emissions. While warming is likely to reduce soil moisture, melt water from a deeper snow pack alleviates water stress in the early growing season. The study emphasizes the ecological importance of changes in winter precipitation in the Arctic, which can interact with climate-warming effects. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Leaf anatomy, BVOC emission and CO2 exchange of arctic plants following snow addition and summer warming

PubMed Central

Schollert, Michelle; Kivimäenpää, Minna; Michelsen, Anders; Blok, Daan; Rinnan, Riikka

2017-01-01

Background and Aims Climate change in the Arctic is projected to increase temperature, precipitation and snowfall. This may alter leaf anatomy and gas exchange either directly or indirectly. Our aim was to assess whether increased snow depth and warming modify leaf anatomy and affect biogenic volatile organic compound (BVOC) emissions and CO2 exchange of the widespread arctic shrubs Betula nana and Empetrum nigrum ssp. hermaphroditum. Methods Measurements were conducted in a full-factorial field experiment in Central West Greenland, with passive summer warming by open-top chambers and snow addition using snow fences. Leaf anatomy was assessed using light microscopy and scanning electron microscopy. BVOC emissions were measured using a dynamic enclosure system and collection of BVOCs into adsorbent cartridges analysed by gas chromatography–mass spectrometry. Carbon dioxide exchange was measured using an infrared gas analyser. Key Results Despite a later snowmelt and reduced photosynthesis for B. nana especially, no apparent delays in the BVOC emissions were observed in response to snow addition. Only a few effects of the treatments were seen for the BVOC emissions, with sesquiterpenes being the most responsive compound group. Snow addition affected leaf anatomy by increasing the glandular trichome density in B. nana and modifying the mesophyll of E. hermaphroditum. The open-top chambers thickened the epidermis of B. nana, while increasing the glandular trichome density and reducing the palisade:spongy mesophyll ratio in E. hermaphroditum. Conclusions Leaf anatomy was modified by both treatments already after the first winter and we suggest links between leaf anatomy, CO2 exchange and BVOC emissions. While warming is likely to reduce soil moisture, melt water from a deeper snow pack alleviates water stress in the early growing season. The study emphasizes the ecological importance of changes in winter precipitation in the Arctic, which can interact with climate-warming effects. PMID:28064192

Quantitative patterns between plant volatile emissions induced by biotic stresses and the degree of damage

PubMed Central

Niinemets, Ülo; Kännaste, Astrid; Copolovici, Lucian

2013-01-01

Plants have to cope with a plethora of biotic stresses such as herbivory and pathogen attacks throughout their life cycle. The biotic stresses typically trigger rapid emissions of volatile products of lipoxygenase (LOX) pathway (LOX products: various C6 aldehydes, alcohols, and derivatives, also called green leaf volatiles) associated with oxidative burst. Further a variety of defense pathways is activated, leading to induction of synthesis and emission of a complex blend of volatiles, often including methyl salicylate, indole, mono-, homo-, and sesquiterpenes. The airborne volatiles are involved in systemic responses leading to elicitation of emissions from non-damaged plant parts. For several abiotic stresses, it has been demonstrated that volatile emissions are quantitatively related to the stress dose. The biotic impacts under natural conditions vary in severity from mild to severe, but it is unclear whether volatile emissions also scale with the severity of biotic stresses in a dose-dependent manner. Furthermore, biotic impacts are typically recurrent, but it is poorly understood how direct stress-triggered and systemic emission responses are silenced during periods intervening sequential stress events. Here we review the information on induced emissions elicited in response to biotic attacks, and argue that biotic stress severity vs. emission rate relationships should follow principally the same dose–response relationships as previously demonstrated for different abiotic stresses. Analysis of several case studies investigating the elicitation of emissions in response to chewing herbivores, aphids, rust fungi, powdery mildew, and Botrytis, suggests that induced emissions do respond to stress severity in dose-dependent manner. Bi-phasic emission kinetics of several induced volatiles have been demonstrated in these experiments, suggesting that next to immediate stress-triggered emissions, biotic stress elicited emissions typically have a secondary induction response, possibly reflecting a systemic response. The dose–response relationships can also vary in dependence on plant genotype, herbivore feeding behavior, and plant pre-stress physiological status. Overall, the evidence suggests that there are quantitative relationships between the biotic stress severity and induced volatile emissions. These relationships constitute an encouraging platform to develop quantitative plant stress response models. PMID:23888161

Digestion and absorption ofEucalyptus essential oils in greater glider (Petauroide svolans) and brushtail possum (Trichosurus vulpecula).

PubMed

Foley, W J; Lassak, E V; Brophy, J

1987-11-01

Measurements were made of the quantity and composition of the steam-volatile essential oils in gastrointestinal tract contents of greater gliders fedEucalyptus radiata foliage and brushtail possums fedE. melliodora foliage. In both species, there was less oil in the stomach contents than in an equivalent mass of foliage. Only minor losses of leaf oils occurred during mastication by greater gliders, and absorption from the stomach appeared to be the major reason for the difference in the oil content of ingested leaves and of stomach contents. The apparent digestibility of oils over the whole gut was 96-97 %, although oils from the cecum and feces of both species contained compounds not present in the original leaf oils. Absorption of oils before they reach the hindgut should reduce the severity of antimicrobial effects but may involve a metabolic cost to the animal in detoxification and excretion.

Foliar Essential Oil Glands of Eucalyptus Subgenus Eucalyptus (Myrtaceae) Are a Rich Source of Flavonoids and Related Non-Volatile Constituents

PubMed Central

Nicolle, Dean; Woodrow, Ian E.

2016-01-01

The sub-dermal secretory cavities (glands) embedded within the leaves of Eucalyptus (Myrtaceae) were once thought to be the exclusive repositories of monoterpene and sesquiterpene oils. Recent research has debunked this theory and shown that abundant non-volatile compounds also occur within foliar glands. In particular, glands of four species in subgenus Eucalyptus contain the biologically active flavanone pinocembrin. Pinocembrin shows great promise as a pharmaceutical and is predominantly plant-sourced, so Eucalyptus could be a potential commercial source of such compounds. To explore this we quantified and assessed the purity of pinocembrin in glands of 11 species of E. subg. Eucalyptus using Electro-Spray Ionisation Liquid Chromatography Mass Spectrometry of acetonitrile extracts and Gas Chromatography Mass Spectrometry analyses of hexane extracts of isolated glands which were free from other leaf tissues. Our results showed that the glands of subgenus Eucalyptus contain numerous flavanones that are structurally related to pinocembrin and often present in much greater abundance. The maximum concentration of pinocembrin was 2 mg g-1 dry leaf found in E. stellulata, whereas that of dimethylpinocembrin (5,7-dimethoxyflavanone) was 10 mg g-1 in E. oreades and that of pinostrobin (5-hydroxy-7-methoxyflavanone) was 12 mg g-1 in E. nitida. We also found that the flavanones are exclusively located within the foliar glands rather than distributed throughout leaf tissues. The flavanones differ from the non-methylated pinocembrin in the degree and positions of methylation. This finding is particularly important given the attractiveness of methylated flavonoids as pharmaceuticals and therapeutics. Another important finding was that glands of some members of the subgenus also contain flavanone O-glucosides and flavanone-β-triketone conjugates. In addition, glands contain free β-triketones, β-triketone heterodimers and chromone C-glucosides. Therefore, the foliar glands of this taxonomically distinct group of plants are a rich source of a range of flavonoids and other biologically active compounds with great commercial potential. PMID:26977933

Foliar Essential Oil Glands of Eucalyptus Subgenus Eucalyptus (Myrtaceae) Are a Rich Source of Flavonoids and Related Non-Volatile Constituents.

PubMed

Goodger, Jason Q D; Seneratne, Samiddhi L; Nicolle, Dean; Woodrow, Ian E

2016-01-01

The sub-dermal secretory cavities (glands) embedded within the leaves of Eucalyptus (Myrtaceae) were once thought to be the exclusive repositories of monoterpene and sesquiterpene oils. Recent research has debunked this theory and shown that abundant non-volatile compounds also occur within foliar glands. In particular, glands of four species in subgenus Eucalyptus contain the biologically active flavanone pinocembrin. Pinocembrin shows great promise as a pharmaceutical and is predominantly plant-sourced, so Eucalyptus could be a potential commercial source of such compounds. To explore this we quantified and assessed the purity of pinocembrin in glands of 11 species of E. subg. Eucalyptus using Electro-Spray Ionisation Liquid Chromatography Mass Spectrometry of acetonitrile extracts and Gas Chromatography Mass Spectrometry analyses of hexane extracts of isolated glands which were free from other leaf tissues. Our results showed that the glands of subgenus Eucalyptus contain numerous flavanones that are structurally related to pinocembrin and often present in much greater abundance. The maximum concentration of pinocembrin was 2 mg g-1 dry leaf found in E. stellulata, whereas that of dimethylpinocembrin (5,7-dimethoxyflavanone) was 10 mg g-1 in E. oreades and that of pinostrobin (5-hydroxy-7-methoxyflavanone) was 12 mg g-1 in E. nitida. We also found that the flavanones are exclusively located within the foliar glands rather than distributed throughout leaf tissues. The flavanones differ from the non-methylated pinocembrin in the degree and positions of methylation. This finding is particularly important given the attractiveness of methylated flavonoids as pharmaceuticals and therapeutics. Another important finding was that glands of some members of the subgenus also contain flavanone O-glucosides and flavanone-β-triketone conjugates. In addition, glands contain free β-triketones, β-triketone heterodimers and chromone C-glucosides. Therefore, the foliar glands of this taxonomically distinct group of plants are a rich source of a range of flavonoids and other biologically active compounds with great commercial potential.

VOC emissions and carbon balance of two bioenergy plantations in response to nitrogen fertilization: A comparison of Miscanthus and Salix.

PubMed

Hu, Bin; Jarosch, Ann-Mareike; Gauder, Martin; Graeff-Hönninger, Simone; Schnitzler, Jörg-Peter; Grote, Rüdiger; Rennenberg, Heinz; Kreuzwieser, Jürgen

2018-06-01

Energy crops are an important renewable source for energy production in future. To ensure high yields of crops, N fertilization is a common practice. However, knowledge on environmental impacts of bioenergy plantations, particularly in systems involving trees, and the effects of N fertilization is scarce. We studied the emission of volatile organic compounds (VOC), which negatively affect the environment by contributing to tropospheric ozone and aerosols formation, from Miscanthus and willow plantations. Particularly, we aimed at quantifying the effect of N fertilization on VOC emission. For this purpose, we determined plant traits, photosynthetic gas exchange and VOC emission rates of the two systems as affected by N fertilization (0 and 80 kg ha -1 yr -1 ). Additionally, we used a modelling approach to simulate (i) the annual VOC emission rates as well as (ii) the OH . reactivity resulting from individual VOC emitted. Total VOC emissions from Salix was 1.5- and 2.5-fold higher compared to Miscanthus in non-fertilized and fertilized plantations, respectively. Isoprene was the dominating VOC in Salix (80-130 μg g -1 DW h -1 ), whereas it was negligible in Miscanthus. We identified twenty-eight VOC compounds, which were released by Miscanthus with the green leaf volatile hexanal as well as dimethyl benzene, dihydrofuranone, phenol, and decanal as the dominant volatiles. The pattern of VOC released from this species clearly differed to the pattern emitted by Salix. OH . reactivity from VOC released by Salix was ca. 8-times higher than that of Miscanthus. N fertilization enhanced stand level VOC emissions, mainly by promoting the leaf area index and only marginally by enhancing the basal emission capacity of leaves. Considering the higher productivity of fertilized Miscanthus compared to Salix together with the considerably lower OH . reactivity per weight unit of biomass produced, qualified the C 4 -perennial grass Miscanthus as a superior source of future bioenergy production. Copyright © 2018 Elsevier Ltd. All rights reserved.

Irreversible impacts of heat on the emissions of monoterpenes, sesquiterpenes, phenolic BVOC and green leaf volatiles from several tree species

NASA Astrophysics Data System (ADS)

Kleist, E.; Mentel, T. F.; Andres, S.; Bohne, A.; Folkers, A.; Kiendler-Scharr, A.; Rudich, Y.; Springer, M.; Tillmann, R.; Wildt, J.

2012-12-01

Climate change will induce extended heat waves to parts of the vegetation more frequently. High temperatures may act as stress (thermal stress) on plants changing emissions of biogenic volatile organic compounds (BVOCs). As BVOCs impact the atmospheric oxidation cycle and aerosol formation, it is important to explore possible alterations of BVOC emissions under high temperature conditions. Applying heat to European beech, Palestine oak, Scots pine, and Norway spruce in a laboratory setup either caused the well-known exponential increases of BVOC emissions or induced irreversible changes of BVOC emissions. Considering only irreversible changes of BVOC emissions as stress impacts, we found that high temperatures decreased the de novo emissions of monoterpenes, sesquiterpenes and phenolic BVOC. This behaviour was independent of the tree species and whether the de novo emissions were constitutive or induced by biotic stress. In contrast, application of thermal stress to conifers amplified the release of monoterpenes stored in resin ducts of conifers and induced emissions of green leaf volatiles. In particular during insect attack on conifers, the plants showed de novo emissions of sesquiterpenes and phenolic BVOCs, which exceeded constitutive monoterpene emissions from pools. The heat-induced decrease of de novo emissions was larger than the increased monoterpene release caused by damage of resin ducts. For insect-infested conifers the net effect of thermal stress on BVOC emissions could be an overall decrease. Global change-induced heat waves may put hard thermal stress on plants. If so, we project that BVOC emissions increase is more than predicted by models only in areas predominantly covered with conifers that do not emit high amounts of sesquiterpenes and phenolic BVOCs. Otherwise overall effects of high temperature stress will be lower increases of BVOC emissions than predicted by algorithms that do not consider stress impacts.

Leaf volatile compounds and the distribution of ant patrollingin an ant-plant protection mutualism: Preliminary results on Leonardoxa (Fabaceae: Caesalpinioideae) and Petalomyrmex(Formicidae: Formicinae)

NASA Astrophysics Data System (ADS)

Brouat, Carine; McKey, Doyle; Bessière, Jean-Marie; Pascal, Laurence; Hossaert-McKey, Martine

2000-12-01

While observations suggest that plant chemicals could be important in maintaining the specificity and permitting the functioning of ant-plant symbioses, they have been little studied. We report here the strongest evidence yet for chemical signalling between ants and plants in a specific ant-plant protection symbiosis. In the mutualism between Leonardoxa africana subsp. africana and Petalomyrmex phylax, ants continuously patrol young leaves, which are vulnerable to attacks by phytophagous insects. We provide experimental evidence for chemical mediation of ant attraction to young leaves in this system. By a comparative analysis of the related non-myrmecophytic tree L. africana subsp. gracilicaulis, we identify likely candidates for attractant molecules, and suggest they may function not only as signals but also as resources. We also propose hypotheses on the evolutionary origin of these plant volatiles, and of the responses to them by mutualistic ants.

Reducing the pollution risk of pesticide using nano networks induced by irradiation and hydrothermal treatment.

PubMed

Sun, Xiao; Liu, Zuojun; Zhang, Guilong; Qiu, Guannan; Zhong, Naiqin; Wu, Lifang; Cai, Dongqing; Wu, Zhengyan

2015-01-01

Traditional pesticides (TP) often do not adhere tightly to crop foliage. They can easily enter the surrounding environment through precipitation and volatilization. This can result in the pollution of the surrounding soil, water, and air. To reduce pesticide pollution, we developed a loss-control pesticide (LCP) by adding attapulgite with a nano networks structure fabricated using high energy electron beam (HEEB) irradiation and hydrothermal treatment to TP. HEEB irradiation effectively dispersed originally aggregated attapulgite through modified thermal, charge, and physical effects. Hydrothermal treatment further enhanced the dispersion of attapulgite to form nano porous networks via thermal and wet expansion effects, which are beneficial for pesticide binding. An LCP has improved retention on crop leaf surfaces. It has a higher adhesion capacity, reduced leaching and volatilization, and extended residual activity compared with the TP formulation. The treatment increases the residual activity of pesticides on crop foliage and decreases environmental pollution.

Function of defensive volatiles in pedunculate oak (Quercus robur) is tricked by the moth Tortrix viridana.

PubMed

Ghirardo, Andrea; Heller, Werner; Fladung, Matthias; Schnitzler, Jörg-Peter; Schroeder, Hilke

2012-12-01

The indirect defences of plants are comprised of herbivore-induced plant volatiles (HIPVs) that among other things attract the natural enemies of insects. However, the actual extent of the benefits of HIPV emissions in complex co-evolved plant-herbivore systems is only poorly understood. The observation that a few Quercus robur L. trees constantly tolerated (T-oaks) infestation by a major pest of oaks (Tortrix viridana L.), compared with heavily defoliated trees (susceptible: S-oaks), lead us to a combined biochemical and behavioural study. We used these evidently different phenotypes to analyse whether the resistance of T-oaks to the herbivore was dependent on the amount and scent of HIPVs and/or differences in non-volatile polyphenolic leaf constituents (as quercetin-, kaempferol- and flavonol glycosides). In addition to non-volatile metabolic differences, typically defensive HIPV emissions differed between S-oaks and T-oaks. Female moths were attracted by the blend of HIPVs from S-oaks, showing significantly higher amounts of (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) and (E)-β-ocimene and avoid T-oaks with relative high fraction of the sesquiterpenes α-farnesene and germacrene D. Hence, the strategy of T-oaks exhibiting directly herbivore-repellent HIPV emissions instead of high emissions of predator-attracting HIPVs of the S-oaks appears to be the better mechanism for avoiding defoliation. © 2012 Blackwell Publishing Ltd.

Seasonality of isoprenoid emissions from a primary rainforest in central Amazonia

DOE PAGES

Alves, Eliane G.; Jardine, Kolby; Tota, Julio; ...

2016-03-23

Tropical rainforests are an important source of isoprenoid and other volatile organic compound (VOC) emissions to the atmosphere. The seasonal variation of these compounds is however still poorly understood. In this study, vertical profiles of mixing ratios of isoprene, total monoterpenes and total sesquiterpenes, were measured within and above the canopy, in a primary rainforest in central Amazonia, using a proton transfer reaction – mass spectrometer (PTR-MS). Fluxes of these compounds from the canopy into the atmosphere were estimated from PTR-MS measurements by using an inverse Lagrangian transport model. Measurements were carried out continuously from September 2010 to January 2011,more » encompassing the dry and wet seasons. Mixing ratios were higher during the dry (isoprene – 2.68 ± 0.9 ppbv, total monoterpenes – 0.67 ± 0.3 ppbv; total sesquiterpenes – 0.09 ± 0.07 ppbv) than the wet season (isoprene – 1.66 ± 0.9 ppbv, total monoterpenes – 0.47 ± 0.2 ppbv; total sesquiterpenes – 0.03 ± 0.02 ppbv) for all compounds. Ambient air temperature and photosynthetically active radiation (PAR) behaved similarly. Daytime isoprene and total monoterpene mixing ratios were highest within the canopy, rather than near the ground or above the canopy. By comparison, daytime total sesquiterpene mixing ratios were highest near the ground. Daytime fluxes varied significantly between seasons for all compounds. The maximums for isoprene (2.53 ± 0.5 µmol m -2 h -1) and total monoterpenes (1.77 ± 0.05 µmol m -2 h -1) were observed in the late dry season, whereas the maximum for total sesquiterpenes was found during the dry-to-wet transition season (0.77 ± 0.1 µmol m -2 h -1). These flux estimates suggest that the canopy is the main source of isoprenoids emitted into the atmosphere for all seasons. However, uncertainties in turbulence parameterization near the ground could affect estimates of fluxes that come from the ground. Leaf phenology seemed to be an important driver of seasonal variation of isoprenoid emissions. Although remote sensing observations of changes in leaf area index were used to estimate leaf phenology, MEGAN 2.1 did not fully capture the behavior of seasonal emissions observed in this study. This could be a result of very local effects on the observed emissions, but also suggest that other parameters need to be better determined in biogenic volatile organic compound (BVOC) models. Our results support established findings that seasonality of isoprenoids are driven by seasonal changes in light, temperature and leaf phenology. However, they suggest that leaf phenology and its role on isoprenoid production and emission from tropical plant species needs to be better understood in order to develop mechanistic explanations for seasonal variation in emissions. This also may reduce the uncertainties of model estimates associated with the responses to environmental factors. Therefore, this study strongly encourages long-term measurements of isoprenoid emissions, environmental factors and leaf phenology from leaf to ecosystem scale, with the purpose of improving BVOC model approaches that can characterize seasonality of isoprenoid emissions from tropical rainforests.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alves, Eliane G.; Jardine, Kolby; Tota, Julio

Tropical rainforests are an important source of isoprenoid and other volatile organic compound (VOC) emissions to the atmosphere. The seasonal variation of these compounds is however still poorly understood. In this study, vertical profiles of mixing ratios of isoprene, total monoterpenes and total sesquiterpenes, were measured within and above the canopy, in a primary rainforest in central Amazonia, using a proton transfer reaction – mass spectrometer (PTR-MS). Fluxes of these compounds from the canopy into the atmosphere were estimated from PTR-MS measurements by using an inverse Lagrangian transport model. Measurements were carried out continuously from September 2010 to January 2011,more » encompassing the dry and wet seasons. Mixing ratios were higher during the dry (isoprene – 2.68 ± 0.9 ppbv, total monoterpenes – 0.67 ± 0.3 ppbv; total sesquiterpenes – 0.09 ± 0.07 ppbv) than the wet season (isoprene – 1.66 ± 0.9 ppbv, total monoterpenes – 0.47 ± 0.2 ppbv; total sesquiterpenes – 0.03 ± 0.02 ppbv) for all compounds. Ambient air temperature and photosynthetically active radiation (PAR) behaved similarly. Daytime isoprene and total monoterpene mixing ratios were highest within the canopy, rather than near the ground or above the canopy. By comparison, daytime total sesquiterpene mixing ratios were highest near the ground. Daytime fluxes varied significantly between seasons for all compounds. The maximums for isoprene (2.53 ± 0.5 µmol m -2 h -1) and total monoterpenes (1.77 ± 0.05 µmol m -2 h -1) were observed in the late dry season, whereas the maximum for total sesquiterpenes was found during the dry-to-wet transition season (0.77 ± 0.1 µmol m -2 h -1). These flux estimates suggest that the canopy is the main source of isoprenoids emitted into the atmosphere for all seasons. However, uncertainties in turbulence parameterization near the ground could affect estimates of fluxes that come from the ground. Leaf phenology seemed to be an important driver of seasonal variation of isoprenoid emissions. Although remote sensing observations of changes in leaf area index were used to estimate leaf phenology, MEGAN 2.1 did not fully capture the behavior of seasonal emissions observed in this study. This could be a result of very local effects on the observed emissions, but also suggest that other parameters need to be better determined in biogenic volatile organic compound (BVOC) models. Our results support established findings that seasonality of isoprenoids are driven by seasonal changes in light, temperature and leaf phenology. However, they suggest that leaf phenology and its role on isoprenoid production and emission from tropical plant species needs to be better understood in order to develop mechanistic explanations for seasonal variation in emissions. This also may reduce the uncertainties of model estimates associated with the responses to environmental factors. Therefore, this study strongly encourages long-term measurements of isoprenoid emissions, environmental factors and leaf phenology from leaf to ecosystem scale, with the purpose of improving BVOC model approaches that can characterize seasonality of isoprenoid emissions from tropical rainforests.« less

Seasonality of isoprenoid emissions from a primary rainforest in central Amazonia

NASA Astrophysics Data System (ADS)

Alves, Eliane G.; Jardine, Kolby; Tota, Julio; Jardine, Angela; Yãnez-Serrano, Ana Maria; Karl, Thomas; Tavares, Julia; Nelson, Bruce; Gu, Dasa; Stavrakou, Trissevgeni; Martin, Scot; Artaxo, Paulo; Manzi, Antonio; Guenther, Alex

2016-03-01

Tropical rainforests are an important source of isoprenoid and other volatile organic compound (VOC) emissions to the atmosphere. The seasonal variation of these compounds is however still poorly understood. In this study, vertical profiles of mixing ratios of isoprene, total monoterpenes and total sesquiterpenes, were measured within and above the canopy, in a primary rainforest in central Amazonia, using a proton transfer reaction - mass spectrometer (PTR-MS). Fluxes of these compounds from the canopy into the atmosphere were estimated from PTR-MS measurements by using an inverse Lagrangian transport model. Measurements were carried out continuously from September 2010 to January 2011, encompassing the dry and wet seasons. Mixing ratios were higher during the dry (isoprene - 2.68 ± 0.9 ppbv, total monoterpenes - 0.67 ± 0.3 ppbv; total sesquiterpenes - 0.09 ± 0.07 ppbv) than the wet season (isoprene - 1.66 ± 0.9 ppbv, total monoterpenes - 0.47 ± 0.2 ppbv; total sesquiterpenes - 0.03 ± 0.02 ppbv) for all compounds. Ambient air temperature and photosynthetically active radiation (PAR) behaved similarly. Daytime isoprene and total monoterpene mixing ratios were highest within the canopy, rather than near the ground or above the canopy. By comparison, daytime total sesquiterpene mixing ratios were highest near the ground. Daytime fluxes varied significantly between seasons for all compounds. The maximums for isoprene (2.53 ± 0.5 µmol m-2 h-1) and total monoterpenes (1.77 ± 0.05 µmol m-2 h-1) were observed in the late dry season, whereas the maximum for total sesquiterpenes was found during the dry-to-wet transition season (0.77 ± 0.1 µmol m-2 h-1). These flux estimates suggest that the canopy is the main source of isoprenoids emitted into the atmosphere for all seasons. However, uncertainties in turbulence parameterization near the ground could affect estimates of fluxes that come from the ground. Leaf phenology seemed to be an important driver of seasonal variation of isoprenoid emissions. Although remote sensing observations of changes in leaf area index were used to estimate leaf phenology, MEGAN 2.1 did not fully capture the behavior of seasonal emissions observed in this study. This could be a result of very local effects on the observed emissions, but also suggest that other parameters need to be better determined in biogenic volatile organic compound (BVOC) models. Our results support established findings that seasonality of isoprenoids are driven by seasonal changes in light, temperature and leaf phenology. However, they suggest that leaf phenology and its role on isoprenoid production and emission from tropical plant species needs to be better understood in order to develop mechanistic explanations for seasonal variation in emissions. This also may reduce the uncertainties of model estimates associated with the responses to environmental factors. Therefore, this study strongly encourages long-term measurements of isoprenoid emissions, environmental factors and leaf phenology from leaf to ecosystem scale, with the purpose of improving BVOC model approaches that can characterize seasonality of isoprenoid emissions from tropical rainforests.

Seasonality of isoprenoid emissions from a primary rainforest in central Amazonia

NASA Astrophysics Data System (ADS)

Alves, E. G.; Jardine, K.; Tota, J.; Jardine, A.; Yáñez-Serrano, A. M.; Karl, T.; Tavares, J.; Nelson, B.; Gu, D.; Stavrakou, T.; Martin, S.; Manzi, A.; Guenther, A.

2015-10-01

Tropical rainforests are an important source of isoprenoid and other Volatile Organic Compound (VOC) emissions to the atmosphere. The seasonal variation of these compounds is however still poorly understood. In this study, profiles were collected of the vertical profile of mixing ratios of isoprene, total monoterpenes and total sesquiterpenes, within and above the canopy, in a primary rainforest in central Amazonia, using a Proton Transfer Reaction-Mass Spectrometer (PTR-MS). Fluxes of these compounds from the canopy into the atmosphere were estimated from PTR-MS measurements by using an inverse Lagrangian transport model. Measurements were carried out continuously from September 2010 to January 2011, encompassing the dry and wet seasons. Mixing ratios were higher during the dry (isoprene - 2.68 ± 0.9 ppbv, total monoterpenes - 0.67 ± 0.3 ppbv; total sesquiterpenes - 0.09 ± 0.07 ppbv) than the wet season (isoprene - 1.66 ± 0.9 ppbv, total monoterpenes - 0.47 ± 0.2 ppbv; total sesquiterpenes - 0.03 ± 0.02 ppbv) for all compounds. Ambient air temperature and photosynthetically active radiation (PAR) behaved similarly. Daytime isoprene and total monoterpene mixing ratios were highest within the canopy, rather than near the ground or above the canopy. By comparison, daytime total sesquiterpene mixing ratios were highest near the ground. Daytime fluxes varied significantly between seasons for all compounds. The maximums for isoprene (2.53 ± 0.5 μmol m-2 h-1) and total monoterpenes (1.77 ± 0.05 μmol m-2 h-1) were observed in the late dry season, whereas the maximum for total sesquiterpenes was found during the dry-to-wet transition season (0.77 ± 0.1 μmol m-2 h-1). These flux estimates suggest that the canopy is the main source of isoprenoids to the atmosphere for all seasons. However, uncertainties in turbulence parameterization near the ground could affect estimates of fluxes that come from the ground. Leaf phenology seemed to be an important driver of seasonal variation of isoprenoid emissions. Although remote sensing observations of changes in leaf area index were used to estimate leaf phenology, MEGAN 2.1 did not fully capture the behavior of seasonal emissions observed in this study. This could be a result of very local effects on the observed emissions, but also suggest that other parameters need to be better determined in Biogenic Volatile Organic Compound (BVOC) models. Our results support established findings that seasonality of isoprenoids are driven by seasonal changes in light, temperature and leaf phenology. However, they suggest that leaf phenology and its role on isoprenoid production and emission from tropical plant species needs to be better understood in order to develop mechanistic explanations for seasonal variation in emissions. This also may reduce the uncertainties of model estimates associated with the responses to environmental factors. Therefore, this study strongly encourages long-term measurements of isoprenoid emissions, environmental factors and leaf phenology from leaf to ecosystem scale, with the purpose of improving BVOC model approaches that can characterize seasonality of isoprenoid emissions from tropical rainforests.

Enhanced Microbial, Functional and Sensory Properties of Herbal Yogurt Fermented with Korean Traditional Plant Extracts.

PubMed

Joung, Jae Yeon; Lee, Ji Young; Ha, Young Sik; Shin, Yong Kook; Kim, Younghoon; Kim, Sae Hun; Oh, Nam Su

2016-01-01

This study evaluated the effects of two Korean traditional plant extracts (Diospyros kaki THUNB. leaf; DK, and Nelumbo nucifera leaf; NN) on the fermentation, functional and sensory properties of herbal yogurts. Compared to control fermentation, all plant extracts increased acidification rate and reduced the time to complete fermentation (pH 4.5). Supplementation of plant extracts and storage time were found to influence the characteristics of the yogurts, contributing to increased viability of starter culture and phenolic compounds. In particular, the increase in the counts of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus was highest (2.95 and 1.14 Log CFU/mL respectively) in DK yogurt. Furthermore, supplementation of the plant extracts significantly influenced to increase the antioxidant activity and water holding capacity and to produce volatile compounds. The higher antioxidant activity and water holding capacity were observed in NN yogurt than DK yogurt. Moreover, all of the sensory characteristics were altered by the addition of plant extracts. Addition of plant extracts increased the scores related to flavor, taste, and texture from plain yogurt without a plant extract, as a result of volatile compounds analysis. Thus, the overall preference was increased by plant extracts. Consequently, supplementation of DK and NN extracts in yogurt enhanced the antioxidant activity and physical property, moreover increased the acceptability of yogurt. These findings demonstrate the possibility of using plant extracts as a functional ingredient in the manufacture of herbal yogurt.

Enhanced Microbial, Functional and Sensory Properties of Herbal Yogurt Fermented with Korean Traditional Plant Extracts

PubMed Central

Joung, Jae Yeon; Lee, Ji Young; Ha, Young Sik; Shin, Yong Kook; Kim, Younghoon; Kim, Sae Hun; Oh, Nam Su

2016-01-01

This study evaluated the effects of two Korean traditional plant extracts (Diospyros kaki THUNB. leaf; DK, and Nelumbo nucifera leaf; NN) on the fermentation, functional and sensory properties of herbal yogurts. Compared to control fermentation, all plant extracts increased acidification rate and reduced the time to complete fermentation (pH 4.5). Supplementation of plant extracts and storage time were found to influence the characteristics of the yogurts, contributing to increased viability of starter culture and phenolic compounds. In particular, the increase in the counts of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus was highest (2.95 and 1.14 Log CFU/mL respectively) in DK yogurt. Furthermore, supplementation of the plant extracts significantly influenced to increase the antioxidant activity and water holding capacity and to produce volatile compounds. The higher antioxidant activity and water holding capacity were observed in NN yogurt than DK yogurt. Moreover, all of the sensory characteristics were altered by the addition of plant extracts. Addition of plant extracts increased the scores related to flavor, taste, and texture from plain yogurt without a plant extract, as a result of volatile compounds analysis. Thus, the overall preference was increased by plant extracts. Consequently, supplementation of DK and NN extracts in yogurt enhanced the antioxidant activity and physical property, moreover increased the acceptability of yogurt. These findings demonstrate the possibility of using plant extracts as a functional ingredient in the manufacture of herbal yogurt. PMID:27499669

Leaf enclosure measurement for determining marijuana volatile organic compound emission factors

NASA Astrophysics Data System (ADS)

Wang, C. T.; Vizuete, W.; Wiedinmyer, C.; Ashworth, K.; Harley, P. C.; Ortega, J. V.

2017-12-01

In 2014, Colorado became the first US state to legalize the industrial-scale cultivation of marijuana plants. There are now more than 700 marijuana cultivation facilities (MCFs) in operation in the greater Denver area. High concentrations of biogenic volatile organic compounds (VOCs), predominantly monoterpenes (C10H16) such as alpha-pinene, myrcene, and limonene have been observed in the grow rooms of MCFs, suggesting MCFs have the potential to release a significant amount of reactive VOCs into the atmosphere. Further, many MCFs are located in the urban core, where other urban emission sources are concentrated, resulting in interactions which can lead to the formation of ozone, impacting air quality. The little research done on marijuana has focused on indoor air quality and occupational exposure, or identification of the compounds associated with the characteristic smells of marijuana plants. We know of no previous studies that have identified or quantified the monoterpene emission rates from marijuana. Here, we collected air samples from leaf enclosures from different marijuana clones at different growth stages onto sorbent cartridges. These samples were analyzed using GC-MS/-FID to identify and quantify the VOCs emitted by growing marijuana plants. These results were then used to estimate basal emission rates at standard conditions (T=30 C, PPFD = 1000 umol/m2/s) using standard algorithms. We discuss the potential impact on air quality from these VOCs emitted into the atmosphere using air quality models.

Effects of Abiotic Factors on HIPV-Mediated Interactions between Plants and Parasitoids

PubMed Central

Becker, Christine; Desneux, Nicolas; Monticelli, Lucie; Fernandez, Xavier; Michel, Thomas; Lavoir, Anne-Violette

2015-01-01

In contrast to constitutively emitted plant volatiles (PV), herbivore-induced plant volatiles (HIPV) are specifically emitted by plants when afflicted with herbivores. HIPV can be perceived by parasitoids and predators which parasitize or prey on the respective herbivores, including parasitic hymenoptera. HIPV act as signals and facilitate host/prey detection. They comprise a blend of compounds: main constituents are terpenoids and “green leaf volatiles.” Constitutive emission of PV is well known to be influenced by abiotic factors like temperature, light intensity, water, and nutrient availability. HIPV share biosynthetic pathways with constitutively emitted PV and might therefore likewise be affected by abiotic conditions. However, the effects of abiotic factors on HIPV-mediated biotic interactions have received only limited attention to date. HIPV being influenced by the plant's growing conditions could have major implications for pest management. Quantitative and qualitative changes in HIPV blends may improve or impair biocontrol. Enhanced emission of HIPV may attract a larger number of natural enemies. Reduced emission rates or altered compositions, however, may render blends imperceptible to parasitoides and predators. Predicting the outcome of these changes is highly important for food production and for ecosystems affected by global climate change. PMID:26788501

Nicotiana tabacum as model for ozone - plant surface reactions

NASA Astrophysics Data System (ADS)

Jud, Werner; Fischer, Lukas; Wohlfahrt, Georg; Tissier, Alain; Canaval, Eva; Hansel, Armin

2015-04-01

Elevated tropospheric ozone concentrations are considered a toxic threat to plants, responsible for global crop losses with associated economic costs of several billion dollars per year. The ensuing injuries have been related to the uptake of ozone through the stomatal pores and oxidative effects damaging the internal leaf tissue. A striking question of current research is the environment and plant specific partitioning of ozone loss between gas phase, stomatal or plant surface sink terms. Here we show results from ozone fumigation experiments using various Nicotiana Tabacum varieties, whose surfaces are covered with different amounts of unsaturated diterpenoids exuded by their glandular trichomes. Exposure to elevated ozone levels (50 to 150 ppbv) for 5 to 15 hours in an exceptionally clean cuvette system did neither result in a reduction of photosynthesis nor caused any visible leaf damage. Both these ozone induced stress effects have been observed previously in ozone fumigation experiments with the ozone sensitive tobacco line Bel-W3. In our case ozone fumigation was accompanied by a continuous release of oxygenated volatile organic compounds, which could be clearly associated to their condensed phase precursors for the first time. Gas phase reactions of ozone were avoided by choosing a high enough gas exchange rate of the plant cuvette system. In the case of the Ambalema variety, that is known to exude only the diterpenoid cis-abienol, ozone fumigation experiments yield the volatiles formaldehyde and methyl vinyl ketone (MVK). The latter could be unequivocally separated from isomeric methacrolein (MACR) by the aid of a Selective Reagent Ion Time-of-Flight Mass Spectrometer (SRI-ToF-MS), which was switched every six minutes from H3O+ to NO+ primary ion mode and vice versa. Consistent with the picture of an ozone protection mechanism caused by reactive diterpenoids at the leaf surface are the results from dark-light experiments. The ozone loss obtained from the difference of ozone measured before and after the plant cuvette was investigated as a function of stomatal opening. Switching from dark to light conditions and thus opening the stomata only a small increase in ozone loss was observed for the Ambalema variety (25%). In the case of the 3H02 variety, a line known to emit almost no diterpenoids, the ozone loss increased by more than 100% when changing from dark to light conditions. It is anticipated that the described effect is of importance also for other plant species emitting low-volatility unsaturated organic compounds (e.g. in form of exudates or resins).

Thin Layer Chromatography-Bioautography and Gas Chromatography-Mass Spectrometry of Antimicrobial Leaf Extracts from Philippine Piper betle L. against Multidrug-Resistant Bacteria.

PubMed

Valle, Demetrio L; Puzon, Juliana Janet M; Cabrera, Esperanza C; Rivera, Windell L

2016-01-01

This study isolated and identified the antimicrobial compounds of Philippine Piper betle L. leaf ethanol extracts by thin layer chromatography- (TLC-) bioautography and gas chromatography-mass spectrometry (GC-MS). Initially, TLC separation of the leaf ethanol extracts provided a maximum of eight compounds with R f values of 0.92, 0.86, 0.76, 0.53, 0.40, 0.25, 0.13, and 0.013, best visualized when inspected under UV 366 nm. Agar-overlay bioautography of the isolated compounds demonstrated two spots with R f values of 0.86 and 0.13 showing inhibitory activities against two Gram-positive multidrug-resistant (MDR) bacteria, namely, methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus. The compound with an R f value of 0.86 also possessed inhibitory activity against Gram-negative MDR bacteria, namely, carbapenem-resistant Enterobacteriaceae-Klebsiella pneumoniae and metallo-β-lactamase-producing Acinetobacter baumannii. GC-MS was performed to identify the semivolatile and volatile compounds present in the leaf ethanol extracts. Six compounds were identified, four of which are new compounds that have not been mentioned in the medical literature. The chemical compounds isolated include ethyl diazoacetate, tris(trifluoromethyl)phosphine, heptafluorobutyrate, 3-fluoro-2-propynenitrite, 4-(2-propenyl)phenol, and eugenol. The results of this study could lead to the development of novel therapeutic agents capable of dealing with specific diseases that either have weakened reaction or are currently not responsive to existing drugs.

Thin Layer Chromatography-Bioautography and Gas Chromatography-Mass Spectrometry of Antimicrobial Leaf Extracts from Philippine Piper betle L. against Multidrug-Resistant Bacteria

PubMed Central

Valle, Demetrio L.; Puzon, Juliana Janet M.; Cabrera, Esperanza C.

2016-01-01

This study isolated and identified the antimicrobial compounds of Philippine Piper betle L. leaf ethanol extracts by thin layer chromatography- (TLC-) bioautography and gas chromatography-mass spectrometry (GC-MS). Initially, TLC separation of the leaf ethanol extracts provided a maximum of eight compounds with R f values of 0.92, 0.86, 0.76, 0.53, 0.40, 0.25, 0.13, and 0.013, best visualized when inspected under UV 366 nm. Agar-overlay bioautography of the isolated compounds demonstrated two spots with R f values of 0.86 and 0.13 showing inhibitory activities against two Gram-positive multidrug-resistant (MDR) bacteria, namely, methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus. The compound with an R f value of 0.86 also possessed inhibitory activity against Gram-negative MDR bacteria, namely, carbapenem-resistant Enterobacteriaceae-Klebsiella pneumoniae and metallo-β-lactamase-producing Acinetobacter baumannii. GC-MS was performed to identify the semivolatile and volatile compounds present in the leaf ethanol extracts. Six compounds were identified, four of which are new compounds that have not been mentioned in the medical literature. The chemical compounds isolated include ethyl diazoacetate, tris(trifluoromethyl)phosphine, heptafluorobutyrate, 3-fluoro-2-propynenitrite, 4-(2-propenyl)phenol, and eugenol. The results of this study could lead to the development of novel therapeutic agents capable of dealing with specific diseases that either have weakened reaction or are currently not responsive to existing drugs. PMID:27478476

Loblolly pine grown under elevated CO2 affects early instar pine sawfly performance.

PubMed

Williams, R S; Lincoln, D E; Thomas, R B

1994-06-01

Seedlings of loblolly pine Pinus taeda (L.), were grown in open-topped field chambers under three CO 2 regimes: ambient, 150 μl l -1 CO 2 above ambient, and 300 μl l -1 CO 2 above ambient. A fourth, non-chambered ambient treatment was included to assess chamber effects. Needles were used in 96 h feeding trials to determine the performance of young, second instar larvae of loblolly pine's principal leaf herbivore, red-headed pine sawfly, Neodiprion lecontei (Fitch). The relative consumption rate of larvae significantly increased on plants grown under elevated CO 2 , and needles grown in the highest CO 2 regime were consumed 21% more rapidly than needles grown in ambient CO 2 . Both the significant decline in leaf nitrogen content and the substantial increase in leaf starch content contributed to a significant increase in the starch:nitrogen ratio in plants grown in elevated CO 2 . Insect consumption rate was negatively related to leaf nitrogen content and positively related to the starch:nitrogen ratio. Of the four volatile leaf monoterpenes measured, only β-pinene exhibited a significant CO 2 effect and declined in plants grown in elevated CO 2 . Although consumption changed, the relative growth rates of larvae were not different among CO 2 treatments. Despite lower nitrogen consumption rates by larvae feeding on the plants grown in elevated CO 2 , nitrogen accumulation rates were the same for all treatments due to a significant increase in nitrogen utilization efficiency. The ability of this insect to respond at an early, potentially susceptible larval stage to poorer food quality and declining levels of a leaf monoterpene suggest that changes in needle quality within pines in future elevated-CO 2 atmospheres may not especially affect young insects and that tree-feeding sawflies may respond in a manner similar to herb-feeding lepidopterans.

The Capacity for Thermal Protection of Photosynthetic Electron Transport Varies for Different Monoterpenes in Quercus ilex1

PubMed Central

Copolovici, Lucian O.; Filella, Iolanda; Llusià, Joan; Niinemets, Ülo; Peñuelas, Josep

2005-01-01

Heat stress resistance of foliar photosynthetic apparatus was investigated in the Mediterranean monoterpene-emitting evergreen sclerophyll species Quercus ilex. Leaf feeding with fosmidomycin, which is a specific inhibitor of the chloroplastic isoprenoid synthesis pathway, essentially stopped monoterpene emission and resulted in the decrease of the optimum temperature of photosynthetic electron transport from approximately 38°C to approximately 30°C. The heat stress resistance was partly restored by fumigation with 4 to 5 nmol mol−1 air concentrations of monoterpene α-pinene but not with fumigations with monoterpene alcohol α-terpineol. Analyses of monoterpene physicochemical characteristics demonstrated that α-pinene was primarily distributed to leaf gas and lipid phases, while α-terpineol was primarily distributed to leaf aqueous phase. Thus, for a common monoterpene uptake rate, α-terpineol is less efficient in stabilizing membrane liquid-crystalline structure and as an antioxidant in plant membranes. Furthermore, α-terpineol uptake rate (U) strongly decreased with increasing temperature, while the uptake rates of α-pinene increased with increasing temperature, providing a further explanation of the lower efficiency of thermal protection by α-terpineol. The temperature-dependent decrease of α-terpineol uptake was both due to decreases in stomatal conductance, gw, and increased volatility of α-terpineol at higher temperature that decreased the monoterpene diffusion gradient between the ambient air (FA) and leaf (FI; U = gw[FA − FI]). Model analyses suggested that α-pinene reacted within the leaf at higher temperatures, possibly within the lipid phase, thereby avoiding the decrease in diffusion gradient, FA − FI. Thus, these data contribute to the hypothesis of the antioxidative protection of leaf membranes during heat stress by monoterpenes. These data further suggest that fumigation with the relatively low atmospheric concentrations of monoterpenes that are occasionally observed during warm windless days in the Mediterranean canopies may significantly improve the heat tolerance of nonemitting vegetation that grows intermixed with emitting species. PMID:16126854

Plasma membrane potential depolarization and cytosolic calcium flux are early events involved in tomato (Solanum lycopersicon) plant-to-plant communication.

PubMed

Zebelo, Simon A; Matsui, Kenji; Ozawa, Rika; Maffei, Massimo E

2012-11-01

Tomato plants respond to herbivory by emitting volatile organic compounds (VOCs), which are released into the surrounding atmosphere. We analyzed the tomato herbivore-induced VOCs and tested the ability of tomato receiver plants to detect tomato donor volatiles by analyzing early responses, including plasma membrane potential (V(m)) variations and cytosolic calcium ([Ca²⁺](cyt)) fluxes. Receiver tomato plants responded within seconds to herbivore-induced VOCs with a strong V(m) depolarization, which was only partly recovered by fluxing receiver plants with clean air. Among emitted volatiles, we identified by GC-MS some green leaf volatiles (GLVs) such as (E)-2-hexenal, (Z)-3-hexenal, (Z)-3-hexenyl acetate, the monoterpene α-pinene, and the sesquiterpene β-caryophyllene. GLVs were found to exert the stronger V(m) depolarization, when compared to α-pinene and β-caryophyllene. Furthermore, V(m) depolarization was found to increase with increasing GLVs concentration. GLVs were also found to induce a strong [Ca²⁺](cyt) increase, particularly when (Z)-3-hexenyl acetate was tested both in solution and with a gas. On the other hand, α-pinene and β-caryophyllene, which also induced a significant V(m) depolarization with respect to controls, did not exert any significant effect on [Ca²⁺](cyt) homeostasis. Our results show for the first time that plant perception of volatile cues (especially GLVs) from the surrounding environment is mediated by early events, occurring within seconds and involving the alteration of the plasma membrane potential and the [Ca²⁺](cyt) flux. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

The Role of Leaf Volatiles of Ludwigia octovalvis (Jacq.) Raven in the Attraction of Altica cyanea (Weber) (Coleoptera: Chrysomelidae).

PubMed

Mitra, Saubhik; Karmakar, Amarnath; Mukherjee, Abhishek; Barik, Anandamay

2017-07-01

Larvae and adults of Altica cyanea (Weber) (Coleoptera: Chrysomelidae) feed on the rice-field weed Ludwigia octovalvis (Jacq.) Raven (Onagraceae), commonly known as willow primrose, which is considered a biocontrol agent of the weed. Volatile organic compounds from undamaged plants, plants after 4, 12, and 36 h of continuous feeding by A. cyanea larvae or adult females and after mechanical damaging were identified by GC-MS and GC-FID analyses. Twenty nine compounds were identified from undamaged plants. 2Z-Penten-1-ol, geraniol, and 1-tridecanol were present in all plants damaged by larvae. In contrast, feeding by adults caused the release of 2Z-penten-1-ol only after 12 and 36 h; whereas geraniol and 1-tridecanol appeared only after 36 h. Farnesyl acetone was detected after 12 and 36 h of feeding by larvae and after 36 h of feeding by adults. Farnesene was detected after 36 h of feeding by larvae and adults. Linalool was unique after 36 h of feeding by larvae. In Y-shaped glass tube olfactometer bioassays, A. cyanea females were attracted to volatiles after 36 h of feeding by larvae or adults compared to volatiles released by undamaged plants. The insects were attracted to five synthetic compounds: 3-hexanol, α-pinene, linalool oxide, geraniol, and phytol. Synthetic blends were more attractive than individual compounds. Compared to undamaged plants, volatiles released by plants, damaged by conspecific individuals, were more attractive to A. cyanea females, due to elevated emissions of 3-hexanol, α-pinene, linalool oxide, geraniol, and phytol.

Identification of a Specific Isoform of Tomato Lipoxygenase (TomloxC) Involved in the Generation of Fatty Acid-Derived Flavor Compounds1

PubMed Central

Chen, Guoping; Hackett, Rachel; Walker, David; Taylor, Andy; Lin, Zhefeng; Grierson, Donald

2004-01-01

There are at least five lipoxygenases (TomloxA, TomloxB, TomloxC, TomloxD, and TomloxE) present in tomato (Lycopersicon esculentum Mill.) fruit, but their role in generation of fruit flavor volatiles has been unclear. To assess the physiological role of TomloxC in the generation of volatile C6 aldehyde and alcohol flavor compounds, we produced transgenic tomato plants with greatly reduced TomloxC using sense and antisense constructs under control of the cauliflower mosaic virus 35S promoter. The expression level of the TomloxC mRNA in some transgenic plants was selectively reduced by gene silencing or antisense inhibition to between 1% and 5% of the wild-type controls, but the expression levels of mRNAs for the four other isoforms were unaffected. The specific depletion of TomloxC in transgenic tomatoes led to a marked reduction in the levels of known flavor volatiles, including hexanal, hexenal, and hexenol, to as little as 1.5% of those of wild-type controls following maceration of ripening fruit. Addition of linoleic or linolenic acid to fruit homogenates significantly increased the levels of flavor volatiles, but the increase with the TomloxC-depleted transgenic fruit extracts was much lower than with the wild-type control. Confocal imaging of tobacco (Nicotiana tabacum) leaf cells expressing a TomloxC-GFP fusion confirmed a chloroplast localization of the protein. Together, these results suggest that TomloxC is a chloroplast-targeted lipoxygenase isoform that can use both linoleic and linolenic acids as substrates to generate volatile C6 flavor compounds. The roles of the other lipoxygenase isoforms are discussed. PMID:15347800

Electrophysiological and Behavioral Responses of Male Fall Webworm Moths (Hyphantria cunea) to Herbivory-Induced Mulberry (Morus alba) Leaf Volatiles

PubMed Central

Tang, Rui; Zhang, Jin Ping; Zhang, Zhong Ning

2012-01-01

Volatile organic compounds (VOCs) were collected from damaged and intact mulberry leaves (Morus alba L., Moraceae) and from Hyphantria cunea larvae by headspace absorption with Super Q columns. We identified their constituents using gas chromatography-mass spectrometry, and evaluated the responses of male H. cunea antennae to the compounds using gas chromatography-flame ionization detection coupled with electroantennographic detection. Eleven VOC constituents were found to stimulate antennae of male H. cunea moths: β-ocimene, hexanal, cis-3-hexenal, limonene, trans-2-hexenal, cyclohexanone, cis-2-penten-1-ol, 6-methyl-5-hepten-2-one, 4-hydroxy-4-methyl-2-pentanone, trans-3-hexen-1-ol, and 2,4-dimethyl-3-pentanol. Nine of these chemicals were released by intact, mechanically-damaged, and herbivore-damaged leaves, while cis-2-penten-1-ol was released only by intact and mechanically-damaged leaves and β-ocimene was released only by herbivore-damaged leaves. Results from wind tunnel experiments conducted with volatile components indicated that male moths were significantly more attracted to herbivory-induced volatiles than the solvent control. Furthermore, male moths' attraction to a sex pheromone lure was increased by herbivory-induced compounds and β-ocimene, but reduced by cis-2-penten-1-ol. A proof long-range field trapping experiment showed that the efficiency of sex pheromone lures in trapping male moths was increased by β-ocimene and reduced by cis-2-penten-1-ol. PMID:23166622

Regulation of Floral Terpenoid Emission and Biosynthesis in Sweet Basil (Ocimum basilicum).

PubMed

Jiang, Yifan; Ye, Jiayan; Li, Shuai; Niinemets, Ülo

2016-12-01

Past studies have focused on the composition of essential oil of Ocimum basilicum leaves, but data on composition and regulation of its aerial emissions, especially floral volatile emissions are scarce. We studied the chemical profile, within-flower spatial distribution (sepals, petals, pistils with stamina and pedicels), diurnal emission kinetics and effects of exogenous methyl jasmonate (MeJA) application on the emission of floral volatiles by dynamic headspace collection and identification using gas chromatography-mass spectrometry (GC-MS) and proton transfer reaction mass spectrometry (PTR-MS). We observed more abundant floral emissions from flowers compared with leaves. Sepals were the main emitters of floral volatiles among the flower parts studied. The emissions of lipoxygenase compounds (LOX) and monoterpenoids, but not sesquiterpene emissions, displayed a diurnal variation driven by light. Response to exogenous MeJA treatment of flowers consisted of a rapid stress response and a longer-term acclimation response. The initial response was associated with enhanced emissions of fatty acid derivatives, monoterpenoids, and sesquiterpenoids without variation of the composition of individual compounds. The longer-term response was associated with enhanced monoterpenoid and sesquiterpenoid emissions with profound changes in the emission spectrum. According to correlated patterns of terpenoid emission changes upon stress, highlighted by a hierarchical cluster analysis, candidate terpenoid synthases responsible for observed diversity and complexity of released terpenoid blends were postulated. We conclude that flower volatile emissions differ quantitatively and qualitatively from leaf emissions, and overall contribute importantly to O. basilicum flavor, especially under stress conditions.

Regulation of Floral Terpenoid Emission and Biosynthesis in Sweet Basil (Ocimum basilicum)

PubMed Central

Jiang, Yifan; Ye, Jiayan; Li, Shuai; Niinemets, Ülo

2018-01-01

Past studies have focused on the composition of essential oil of Ocimum basilicum leaves, but data on composition and regulation of its aerial emissions, especially floral volatile emissions are scarce. We studied the chemical profile, within-flower spatial distribution (sepals, petals, pistils with stamina and pedicels), diurnal emission kinetics and effects of exogenous methyl jasmonate (MeJA) application on the emission of floral volatiles by dynamic headspace collection and identification using gas chromatography-mass spectrometry (GC-MS) and proton transfer reaction mass spectrometry (PTR-MS). We observed more abundant floral emissions from flowers compared with leaves. Sepals were the main emitters of floral volatiles among the flower parts studied. The emissions of lipoxygenase compounds (LOX) and monoterpenoids, but not sesquiterpene emissions, displayed a diurnal variation driven by light. Response to exogenous MeJA treatment of flowers consisted of a rapid stress response and a longer-term acclimation response. The initial response was associated with enhanced emissions of fatty acid derivatives, monoterpenoids, and sesquiterpenoids without variation of the composition of individual compounds. The longer-term response was associated with enhanced monoterpenoid and sesquiterpenoid emissions with profound changes in the emission spectrum. According to correlated patterns of terpenoid emission changes upon stress, highlighted by a hierarchical cluster analysis, candidate terpenoid synthases responsible for observed diversity and complexity of released terpenoid blends were postulated. We conclude that flower volatile emissions differ quantitatively and qualitatively from leaf emissions, and overall contribute importantly to O. basilicum flavor, especially under stress conditions. PMID:29367803

Ozone fumigation under dark/light conditions of Norway Spruce (Picea Abies) and Scots Pine (Pinus Sylvestris)

NASA Astrophysics Data System (ADS)

Canaval, Eva; Jud, Werner; Hansel, Armin

2015-04-01

Norway Spruce (Picea abies) and Scots Pine (Pinus sylvestris) represent dominating tree species in the northern hemisphere. Thus, the understanding of their ozone sensitivity in the light of the expected increasing ozone levels in the future is of great importance. In our experiments we investigated the emissions of volatile organic compounds (VOCs) of 3-4 year old Norway Spruce and Scots Pine seedlings under ozone fumigation (50-150 ppbv) and dark/light conditions. For the experiments the plants were placed in a setup with inert materials including a glass cuvette equipped with a turbulent air inlet and sensors for monitoring a large range of meteorological parameters. Typical conditions were 20-25°C and a relative humidity of 70-90 % for both plant species. A fast gas exchange rate was used to minimize reactions of ozone in the gas phase. A Switchable-Reagent-Ion-Time-of-Flight-MS (SRI-ToF-MS) was used to analyze the VOCs at the cuvette outlet in real-time during changing ozone and light levels. The use of H3O+ and NO+ as reagent ions allows the separation of certain isomers (e.g. aldehydes and ketones) due to different reaction pathways depending on the functional groups of the molecules. Within the Picea abies experiments the ozone loss, defined as the difference of the ozone concentration between cuvette inlet and outlet, remained nearly constant at the transition from dark to light. This indicates that a major part of the supplied ozone is depleted non-stomatally. In contrast the ozone loss increased by 50 % at the transition from dark to light conditions within Pinus sylvestris experiments. In this case the stomata represent the dominant loss channel. Since maximally 0.1% of the ozone loss could be explained by gas phase reactions with monoterpenes and sesquiterpenes, we suggest that ozone reactions on the surface of Picea abies represent the major sink in this case and lead to an light-independent ozone loss. This is supported by the fact that we detected a broad range of unidentified oxygenated ozonolysis products and their fragments, whose amount exceed by far the detected loss of BVOCs under ozone exposure. However, the observed products are not attributable to neither green leaf volatiles nor to other known volatile precursors. Furthermore Picea abies emits a smaller amount of ozone induced green leaf volatiles than Pinus sylvestris. Based on this results we can explain the higher ozone tolerance of Picea abies, which has been observed before. A likely reason for the differences in stomatal and surface ozone loss on the investigated plants are differences in the amount and kind of unsaturated semi-volatile compounds on the needle surface.

Diel variation in fig volatiles across syconium development: making sense of scents.

PubMed

Borges, Renee M; Bessière, Jean-Marie; Ranganathan, Yuvaraj

2013-05-01

Plants produce volatile organic compounds (VOCs) in a variety of contexts that include response to abiotic and biotic stresses, attraction of pollinators and parasitoids, and repulsion of herbivores. Some of these VOCs may also exhibit diel variation in emission. In Ficus racemosa, we examined variation in VOCs released by fig syconia throughout syconium development and between day and night. Syconia are globular enclosed inflorescences that serve as developing nurseries for pollinating and parasitic fig wasps. Syconia are attacked by gallers early in their development, serviced by pollinators in mid phase, and are attractive to parasitoids in response to the development of gallers at later stages. VOC bouquets of the different development phases of the syconium were distinctive, as were their day and night VOC profiles. VOCs such as α-muurolene were characteristic of the pollen-receptive diurnal phase, and may serve to attract the diurnally-active pollinating wasps. Diel patterns of release of volatiles could not be correlated with their predicted volatility as determined by Henry's law constants at ambient temperatures. Therefore, factors other than Henry's law constant such as stomatal conductance or VOC synthesis must explain diel variation in VOC emission. A novel use of weighted gene co-expression network analysis (WGCNA) on the volatilome resulted in seven distinct modules of co-emitted VOCs that could be interpreted on the basis of syconium ecology. Some modules were characterized by the response of fig syconia to early galling by parasitic wasps and consisted largely of green leaf volatiles (GLVs). Other modules, that could be characterized by a combination of syconia response to oviposition and tissue feeding by larvae of herbivorous galler pollinators as well as of parasitized wasps, consisted largely of putative herbivore-induced plant volatiles (HIPVs). We demonstrated the usefulness of WGCNA analysis of the volatilome in making sense of the scents produced by the syconia at different stages and diel phases of their development.

How rainfall, relative humidity and temperature influence volatile emissions from apple trees in situ.

PubMed

Vallat, Armelle; Gu, Hainan; Dorn, Silvia

2005-07-01

Headspace volatiles from apple-bearing twigs were collected in the field with a Radiello sampler during three different diurnal periods over the complete fruit growing season. Analyses by thermal desorption-GC-MS identified a total of 62 compounds in changing quantities, including the terpenoids alpha-pinene, camphene, beta-pinene, limonene, beta-caryophyllene and (E,E)-alpha-farnesene, the aldehydes (E)-2-hexenal, benzaldehyde and nonanal, and the alcohol (Z)-3-hexen-1-ol. The variations in emission of these plant odours were statistically related to temperature, humidity and rainfall in the field. Remarkably, rainfall had a significant positive influence on changes in volatile release during all three diurnal periods, and further factors of significance were temperature and relative humidity around noon, relative humidity in the late afternoon, and temperature and relative humidity during the night. Rainfall was associated consistently with an increase in the late afternoon in terpene and aldehyde volatiles with a known repellent effect on the codling moth, one of the key pests of apple fruit. During the summer of 2003, a season characterized by below-average rainfall, some postulated effects of drought on trees were tested by establishing correlations with rainfall. Emissions of the wood terpenes alpha-pinene, beta-pinene and limonene were negatively correlated with rainfall. Another monoterpene, camphene, was only detected in this summer but not in the previous years, and its emissions were negatively correlated with rainfall, further supporting the theory that drought can result in higher formation of secondary metabolites. Finally, the two green leaf volatiles (E)-2-hexenal and (Z)-3-hexen-1-ol were negatively correlated with rainfall, coinciding well with the expectation that water deficit stress increases activity of lipoxygenase. To our knowledge, this work represents the first empirical study concerning the influence of abiotic factors on volatile emissions from apple trees in situ.

Assessment of volatile organic compound emissions from ecosystems of China

NASA Astrophysics Data System (ADS)

Klinger, L. F.; Li, Q.-J.; Guenther, A. B.; Greenberg, J. P.; Baker, B.; Bai, J.-H.

2002-11-01

Isoprene, monoterpene, and other volatile organic compound (VOC) emissions from grasslands, shrublands, forests, and peatlands in China were characterized to estimate their regional magnitudes and to compare these emissions with those from landscapes of North America, Europe, and Africa. Ecological and VOC emission sampling was conducted at 52 sites centered in and around major research stations located in seven different regions of China: Inner Mongolia (temperate), Changbai Mountain (boreal-temperate), Beijing Mountain (temperate), Dinghu Mountain (subtropical), Ailao Mountain (subtropical), Kunming (subtropical), and Xishuangbanna (tropical). Transects were used to sample plant species and growth form composition, leafy (green) biomass, and leaf area in forests representing nearly all the major forest types of China. Leafy biomass was determined using generic algorithms based on tree diameter, canopy structure, and absolute cover. Measurements of VOC emissions were made on 386 of the 541 recorded species using a portable photo-ionization detector method. For 105 species, VOC emissions were also measured using a flow-through leaf cuvette sampling/gas chromatography analysis method. Results indicate that isoprene and monoterpene emissions, as well as leafy biomass, vary systematically along gradients of ecological succession in the same manner found in previous studies in the United States, Canada, and Africa. Applying these results to a regional VOC emissions model, we arrive at a value of 21 Tg C for total annual biogenic VOC emissions from China, compared to 5 Tg C of VOCs released annually from anthropogenic sources there. The isoprene and monoterpene emissions are nearly the same as those reported for Europe, which is comparable in size to China.

Factors Influencing Male Plutella xylostella (Lepidoptera: Plutellidae) Capture Rates in Sex Pheromone-Baited Traps on Canola in Western Canada.

PubMed

Miluch, C E; Dosdall, L M; Evenden, M L

2014-12-01

Optimization of male moth trapping rates in sex pheromone-baited traps plays a key role in managing Plutella xylostella (L.). We investigated various ways to increase the attractiveness of pheromone-baited traps to P. xylostella in canola agroecosystems in AB, Canada. Factors tested included pheromone blend and dose, addition of a green leaf volatile to the pheromone at different times during the season, lure type, trap color, and height. The industry standard dose of 100 μg of pheromone (four-component blend) per lure (ConTech Enterprises Inc., Delta, British Columbia [BC], Canada) captured the most moths in the two lure types tested. Traps baited with pheromone released from gray rubber septa captured more males than those baited with red rubber septa. Traps baited with lures in which Z11-16: Ac is the main component attracted significantly more moths than those in which Z11-16: Ald is the main component. The addition of the green leaf volatile, (Z)-3-hexenyl acetate, to pheromone at a range of doses, did not increase moth capture at any point during the canola growing season. Unpainted white traps captured significantly more male moths than pheromone-baited traps that were painted yellow. Trap height had no significant effect on moth capture. Recommendations for monitoring P. xylostella in canola agroecosystems of western Canada include using a pheromone blend with Z11-16: Ac as the main component released from gray rubber septa at a dose of 100 μg. © 2014 Entomological Society of America.

Biochemical methane potential, biodegradability, alkali treatment and influence of chemical composition on methane yield of yard wastes.

PubMed

Gunaseelan, Victor Nallathambi

2016-03-01

In this study, the biochemical CH4 potential, rate, biodegradability, NaOH treatment and the influence of chemical composition on CH4 yield of yard wastes generated from seven trees were examined. All the plant parts were sampled for their chemical composition and subjected to the biochemical CH4 potential assay. The component parts exhibited significant variation in biochemical CH4 potential, which was reflected in their ultimate CH4 yields that ranged from 109 to 382 ml g(-1) volatile solids added and their rate constants that ranged from 0.042 to 0.173 d(-1). The biodegradability of the yard wastes ranged from 0.26 to 0.86. Variation in the biochemical CH4 potential of the yard wastes could be attributed to variation in the chemical composition of the different fractions. In the Thespesia yellow withered leaf, Tamarindus fruit pericarp and Albizia pod husk, NaOH treatment enhanced the ultimate CH4 yields by 17%, 77% and 63%, respectively, and biodegradability by 15%, 77% and 61%, respectively, compared with the untreated samples. The effectiveness of NaOH treatment varied for different yard wastes, depending on the amounts of acid detergent fibre content. Gliricidia petals, Prosopis leaf, inflorescence and immature pod, Tamarindus seeds, Albizia seeds, Cassia seeds and Delonix seeds exhibited CH4 yields higher than 300 ml g(-1) volatile solids added. Multiple linear regression models for predicting the ultimate CH4 yield and biodegradability of yard wastes were designed from the results of this work. © The Author(s) 2016.

Characterization of polar organosulfates in secondary organic aerosol from the unsaturated aldehydes 2-E-pentenal, 2-E-hexenal, and 3-Z-hexenal

EPA Pesticide Factsheets

We show in the present study that the unsaturated aldehydes, 2-E-pentenal, 2-E-hexenal and 3-Z-hexenal, are biogenic volatile organic compound (BVOC) precursors for polar organosulfates with molecular weighs (MWs) 230 and 214, which are also present in ambient fine aerosol from a forested site, i.e., K-puszta, Hungary. These results complement those obtained in a previous study showing that the green leaf aldehyde 3-Z-hexenal serves as a precursor for MW 226 organosulfates. Thus, in addition to isoprene, the green leaf volatiles 2-E-hexenal and 3-Z-hexenal, emitted due to plant stress (mechanical wounding or insect attack), and 2-E-pentenal, a photolysis product of 3-Z-hexenal, should be taken into account for secondary organic aerosol and organosulfate formation. Polar organosulfates are of climatic relevance because of their hydrophilic properties and cloud effects. Extensive use was made of organic mass spectrometry (MS) and detailed interpretation of MS data (i.e., ion trap MS and accurate mass measurements) to elucidate the chemical structures of the MW 230, 214 and 170 organosulfates formed from 2-E-pentenal and indirectly from 2-E-hexenal and 3-Z-hexenal. In addition, quantum chemical calculations were performed to explain the different mass spectral behavior of 2,3-dihydroxypentanoic acid sulfate derivatives, where only the isomer with the sulfate group at C-3 results in the loss of SO3. The MW 214 organosulfates formed from 2-E-pentenal are explained by

The colors of autumn leaves as symptoms of cellular recycling and defenses against environmental stresses.

PubMed

Ougham, Helen J; Morris, Phillip; Thomas, Howard

2005-01-01

The color changes that occur during foliar senescence are directly related to the regulation of nutrient mobilization and resorption from leaf cells, often under conditions of biotic and abiotic stress. Chlorophyll is degraded through a metabolic pathway that becomes specifically activated in senescence. Chlorophyll catabolic enzymes and genes have been identified and characterized and aspects of their regulation analyzed. Particular genetic interventions in the pathway lead to disruptions in protein mobilization and increased sensitivity to light-dependent cell damage and death. The chemistry and metabolism of carotenoid and anthocyanin pigments in senescing leaves are considered. Bright autumn colors observed in the foliage of some woody species have been hypothesized to act as a defense signal to potential insect herbivores. Critical consideration of the biochemical and physiological features of normal leaf senescence leads to the conclusion that accumulating or unmasking compounds with new colors are unlikely to represent a costly investment on the part of the tree. The influences of human evolutionary and social history on our own perception of autumn coloration are discussed. The possibility that insect herbivores may respond to volatiles emitted during leaf senescence, rather than to bright colors, is also presented. Finally, some new approaches to the analysis of protein recycling in senescence are briefly considered.

[Results of salad machine experiment within the MARS-500 project].

PubMed

Berkovich, Iu A; Erokhin, A N; Ziablova, N V; Krivobok, A S; Krivobok, N M; Smolianina, S O; Mukhamedieva, L N; Pakhomova, A A; Novikova, N D; Poddubko, S V; Korsak, I V

2012-01-01

The salad machine experiment was aimed to fulfill performance testing of a prototype of space conveyor-type cylindrical greenhouse PHYTOCYCLE-SL, to study growth and development of plants, and to evaluate microbial contamination of equipment in the closed manned environment. Crops of leaf cabbage Brassica chinensis L., cultivar Vesnianka were raised in the time interval between MARS-500 days 417 and 515. The greenhouse proved it serviceability demanding 17 min/(man x d) in the normal mode. Most likely that the slow growth rate and deviations in plant morphology were caused by the presence of volatile pollutants in the greenhouse compartment Accumulation of micromycetes was observed at the sites of humid surfaces contact with ambient air; reduction of the artificial soil area contacting with air decreased population of micromycetes in 40 times. Cabbage leafs were free of pathogenic microflora. These results of the experiment helped develop recommendations on how to work out some units and systems in projectable greenhouse VITACYCLE-T

Effect of Pineapple Leaf Fibers (PALF) concentration on nanofibers formation by electrospinning

NASA Astrophysics Data System (ADS)

Surip, S. N.; Aziz, F. M. Abdul; Bonnia, N. N.; Sekak, K. A.

2018-01-01

Electrospinning method has been studied widely in producing nanofibers due to its straightforward and versatile method. In this study, Pineapple Leaf Fibers (PALF) solution were electrospinning to obtain mat of PALF electrospun. PALF were diluted in Trifluoacetic Acid (TFA) into five different concentrations to study the effect of concentration to the nanofibers formation. Raw sample of PALF (PALFraw), PALF after dewax (PALFdewax) and PALF after dilute with TFA (PALFTFA) were analyzed and compared using FTIR to study the structural change occur. TFA solvent has removed and recreated some of the functional group in PALF thus disrupt strong hydrogen bonds that hold hemicellulose, cellulose and lignin together. All the PALF sample has been proceed to electrospinning process. Low concentration of solution cause the solution jet to break up even before reach the collector however high concentration of solution made the solvent volatile faster and the solution dried easily. Therefore, PALF with optimum concentration of 0.02 gml-1 had favors the formation of nanofibers and succeed in forming membrane at the collector.

Grape cluster microclimate influences the aroma composition of Sauvignon blanc wine.

PubMed

Martin, Damian; Grose, Claire; Fedrizzi, Bruno; Stuart, Lily; Albright, Abby; McLachlan, Andrew

2016-11-01

New Zealand Sauvignon blanc (SB) wines are characterised by a distinctive combination of tropical-fruity and green-herbaceous aromatic compounds. The influence of sunlight exposure of grape clusters on juice and wine composition was investigated, with the aim of manipulating aromatic compounds in SB wine. In the absence of basal leaf removal SB clusters naturally exposed to sunlight were riper than shaded clusters, evidenced by higher total soluble solids (TSS) and proline, and lower malic acid, 3-isobutyl-2-methoxypyrazine (IBMP) and arginine. Volatile thiols in wines did not differ between shaded and exposed clusters. At equivalent TSS, cluster exposure had little or no effect on malic acid concentration. Conversely, wine from shaded clusters had almost double the IBMP concentration of wine from exposed clusters at equivalent TSS. The effects on SB juice and wine composition of natural variations in cluster microclimate are not comparable with the effects of cluster exposure created through leaf removal. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of a method for removing cesium and reducing the volume of leaf litter from broad-leaved trees contaminated by the Fukushima Daiichi nuclear accident during the Great East Japan Earthquake.

PubMed

Harada, Shigeki; Yanagisawa, Mitsunori

2017-04-01

The town of Marumori in southern Miyagi Prefecture borders on Fukushima Prefecture, and following the accident at the Fukushima Daiichi nuclear power plant, there were concerns about cesium deposition in forested areas. One of the authors of this paper has continually surveyed leaf litter from the forested areas. As leaf litter may be a source of cesium contamination from the forest to downstream areas, we considered a simplified version of wet oxidation, a method previously presented by one of the authors of this study, as a technology to reduce leaf litter weight and cesium concentration, separating radioactive nuclides from non-radioactive ones, in leaf litter. We tested our method in three experiments. Experiment 1 used new leaf litter (232 Bq/kg) from the surface of a small stream at the forest edge nearby an area with air dose level higher than the national standard threshold of 0.23 μSv/h for the implementation of governmental decontamination works. Experiment 2 applied wet oxidation to older leaf litter (705 Bq/kg) harvested from a pasture nearby the stream mentioned above. We also used the same leaf litter in experiment 3 for a cesium release tests using pure water. In experiment 1 and 2 we treated leaf litter with a sodium hypochlorite solution, optimizing sodium hypochlorite concentration and reaction temperature. We measured a 50-60% decrease in the leaf litter weight and a 60% decrease in the cesium concentration. Moreover, we also measured the amount of cesium washout. The cesium budget of experiment 1 showed no cesium gasification (wet oxidation avoids airborne cesium as this element is prone to be volatile at 600 °C), and that high sodium hypochlorite concentration and high temperature had a strong positive effect on leaf litter volume reduction and cesium decontamination. Experiment 2 confirmed the reproducibility of these results in leaves with different cesium concentration and harvested in different conditions. We could also explain the mechanism behind leaf litter weight and cesium concentration reduction. Experiment 3 helped us to investigate the effects of the matter present on the surface of the water and the contribution of water soluble cesium. Concurrent experiments on changes in leaf litter chemical composition confirmed that our modified wet oxidation method had an effect on the removal of acid-insoluble lignin. Removal of lignin, a refractory component, might allow for a better utilization of the residue left after implementation of the proposed simplified wet oxidation. Thus, real wastes could be smaller than the residues. Together with the observed smaller cesium concentration in the residue, the proposed method in this study is expected to contribute to mitigate the risk due to the fallen leaves containing cesium. Copyright © 2017 Elsevier Ltd. All rights reserved.

Single- versus Multiple-Pest Infestation Affects Differently the Biochemistry of Tomato (Solanum lycopersicum 'Ailsa Craig').

PubMed

Errard, Audrey; Ulrichs, Christian; Kühne, Stefan; Mewis, Inga; Drungowski, Mario; Schreiner, Monika; Baldermann, Susanne

2015-11-25

Tomato is susceptible to pest infestations by both spider mites and aphids. The effects of each individual pest on plants are known, whereas multiple-pest infestations have received little interest. We studied the effects of single- versus multiple-pest infestation by Tetranychus urticae and Myzus persicae on tomato biochemistry (Solanum lycopersicum) by combining a metabolomic approach and analyses of carotenoids using UHPLC-ToF-MS and volatiles using GC-MS. Plants responded differently to aphids and mites after 3 weeks of infestation, and a multiple infestation induced a specific metabolite composition in plants. In addition, we showed that volatiles emissions differed between the adaxial and abaxial leaf epidermes and identified compounds emitted particularly in response to a multiple infestation (cyclohexadecane, dodecane, aromadendrene, and β-elemene). Finally, the carotenoid concentrations in leaves and stems were more affected by multiple than single infestations. Our study highlights and discusses the interplay of biotic stressors within the terpenoid metabolism.

Testing the optimal defence hypothesis for two indirect defences: extrafloral nectar and volatile organic compounds

PubMed Central

Radhika, Venkatesan; Kost, Christian; Bartram, Stefan; Heil, Martin

2008-01-01

Many plants respond to herbivory with an increased production of extrafloral nectar (EFN) and/or volatile organic compounds (VOCs) to attract predatory arthropods as an indirect defensive strategy. In this study, we tested whether these two indirect defences fit the optimal defence hypothesis (ODH), which predicts the within-plant allocation of anti-herbivore defences according to trade-offs between growth and defence. Using jasmonic acid-induced plants of Phaseolus lunatus and Ricinus communis, we tested whether the within-plant distribution pattern of these two indirect defences reflects the fitness value of the respective plant parts. Furthermore, we quantified photosynthetic rates and followed the within-plant transport of assimilates with 13C labelling experiments. EFN secretion and VOC emission were highest in younger leaves. Moreover, the photosynthetic rate increased with leaf age, and pulse-labelling experiments suggested transport of carbon to younger leaves. Our results demonstrate that the ODH can explain the within-plant allocation pattern of both indirect defences studied. PMID:18493790

Preferences of the peripheral olfactory system of Western Flower Thrips, Frankliniella occidentalis towards stereoisomers of common plant volatiles.

PubMed

Abdullah, Zayed S; Butt, Tariq M

Stereochemistry plays a significant role in structure-activity relationships of messenger chemicals. The ability to distinguish between enantiomers and geometric isomers, however, may be limited to certain stereoisomeric substances, depending on the receiver. In this study, we assessed the preference of the peripheral olfactometry system of Western Flower Thrips, F. occidentalis towards ubiquitously expressed host compounds, with a goal of establishing whether particular stereoisomers enhance host odour recognition. We demonstrate that the peripheral olfactory system of a highly polyphagous thysanopteran insect has evolved to become highly sensitive to a type of green leaf volatile, which is highly ubiquitous in the plant kingdom. We show that there is a significantly greater antennal response to the cis isomer, more so than the isomerisation by-product trans -3-hexen-1-ol. We demonstrate that the antennae of a highly polyphagous insect are capable of detecting common plant secondary metabolites in both enantiomeric forms.

Stomatal density and metabolic determinants mediate salt stress adaptation and water use efficiency in basil (Ocimum basilicum L.).

PubMed

Barbieri, Giancarlo; Vallone, Simona; Orsini, Francesco; Paradiso, Roberta; De Pascale, Stefania; Negre-Zakharov, Florence; Maggio, Albino

2012-11-15

Increasing salinity tolerance and water-use efficiency in crop plants are two major challenges that agriculture must face in the next decades. Many physiological mechanisms and molecular components mediating crop response to environmental stresses have been identified. However, the functional inter-links between stress adaptation responses have not been completely understood. Using two basil cultivars (Napoletano and Genovese) with contrasting ability to respond to salt stress, here we demonstrate that reduced stomatal density, high ascorbate level and polyphenol oxidase (PPO) activity coordinately contribute to improve basil adaptation and water use efficiency (WUE) in saline environment. The constitutively reduced stomatal density was associated with a "delayed" accumulation of stress molecules (and growth inhibiting signals) such as abscisic acid (ABA) and proline, in the more tolerant Genovese. Leaf volatile profiling also revealed cultivar-specific patterns, which may suggest a role for the volatile phenylpropanoid eugenol and monoterpenes in conferring stress tolerance via antioxidant and signalling functions. Copyright © 2012 Elsevier GmbH. All rights reserved.

Variations of the chemical composition and bioactivity of essential oils from leaves and stems of Liquidambar styraciflua (Altingiaceae).

PubMed

El-Readi, Mahmoud Z; Eid, Hanaa H; Ashour, Mohamed L; Eid, Safaa Y; Labib, Rola M; Sporer, Frank; Wink, Michael

2013-11-01

This study aimed to evaluate the variations of the chemical composition and bioactivity of essential oils of Liquidambar styraciflua L. (Altingiaceae) collected in different seasons. The oils were analysed by GLC/FID and GLC/MS. The antioxidant activity was investigated by diphenylpicrylhydrazyl (DPPH) and superoxide anion radical scavenging assays and the deoxyribose degradation assay. Inhibition of both 5-lipoxygenase (5-LOX) and prostaglandin E2 (PGE2) production in hepatic cancer (HepG-2) cells were used to assess the anti-inflammatory activity. The cytotoxic activity was investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Altogether, 64 volatile secondary metabolites were identified. The major components of the leaf oil were d-limonene, α-pinene and β-pinene, and of the stem oil were germacrine D, α-cadinol, d-limonene, α-pinene, and β-pinene. Leaf and stem oils collected in spring could reduce DPPH● (IC50 = 3.17 and 2.19 mg/ml) and prevent the degradation of the deoxyribose sugar (IC50 = 17.55 and 14.29 μg/ml). The stem oil exhibited a higher inhibition of both 5-LOX and PGE2 than the leaf oil. The cytotoxic activity of leaf and stem oils was low in cancer cell lines (IC50 = 136.27 and 119.78 μg/ml in cervical cancer (HeLa) cells). Essential oils of L. styraciflua exhibited an interesting anti-inflammatory activity with low cytotoxicity, supporting its traditional use to treat inflammation. © 2013 Royal Pharmaceutical Society.

Biodiversity matters in feedbacks between climate change and air quality: a study using an individual-based model.

PubMed

Wang, Bin; Shuman, Jacquelyn; Shugart, Herman H; Lerdau, Manuel T

2018-03-30

Air quality is closely associated with climate change via the biosphere because plants release large quantities of volatile organic compounds (VOC) that mediate both gaseous pollutants and aerosol dynamics. Earlier studies, which considered only leaf physiology and simply scale up from leaf-level enhancements of emissions, suggest that climate warming enhances whole forest VOC emissions, and these increased VOC emissions aggravate ozone pollution and secondary organic aerosol formation. Using an individual-based forest VOC emissions model, UVAFME-VOC, that simulates system-level emissions by explicitly simulating forest community dynamics to the individual tree level, ecological competition among the individuals of differing size and age, and radiative transfer and leaf function through the canopy, we find that climate warming only sometimes stimulates isoprene emissions (the single largest source of non-methane hydrocarbon) in a southeastern U.S. forest. These complex patterns result from the combination of higher temperatures' stimulating emissions at the leaf level but decreasing the abundance of isoprene-emitting taxa at the community level by causing a decline in the abundance of isoprene-emitting species (Quercus spp.). This ecological effect eventually outweighs the physiological one, thus reducing overall emissions. Such reduced emissions have far-reaching implications for the climate-air-quality relationships that have been established on the paradigm of warming-enhancement VOC emissions from vegetation. This local scale modeling study suggests that community ecology rather than only individual physiology should be integrated into future studies of biosphere-climate-chemistry interactions. © 2018 by the Ecological Society of America.

Measuring volatile organic compounds and stable isotopes emitted from trees and soils of the Biosphere 2 Rainforest

NASA Astrophysics Data System (ADS)

Meraz, J. C.; Meredith, L. K.; Van Haren, J. L. M.; Volkmann, T. H. M.

2017-12-01

Rainforest trees and soils play an important role in volatile organic compound (VOC) emissions. It is known that many rainforest tree species emit these organic compounds, such as terpenes, which can have an impact on the atmosphere and can be indicative of their metabolic functions. Some VOCs also absorb infrared radiation at wavelengths at which water isotopes are measured with laser spectrometers. Normal concentrations are not high enough for ambient sampling, but increased concentrations resulting from soil and plant samples extracted using equilibrium methods affect observed isotope ratios. There is thus a need to characterize volatile emissions from soil and plant samples, and to develop better methods to account for VOC interference during water isotope measurements. In this study, we collected soil and leaf samples from plants of the Biosphere 2 Rainforest Biome, a mesocosm system created to stimulate natural tropical rainforest habitats . Volatile concentrations were measured using a Gasmet DX4015 FTIR analyzer and a custom sampling system with sulfur hexafluoride (SF6) used as a tracer gas to test for leakage, and a commercial laser spectrometer was used for isotopic analysis. We determined that the different types of tree species emit different kinds of VOCs, such as isoprenes, alcohols, and aldehydes, that will potentially have to be accounted for. This study will help build the understanding of which organic compounds are emitted and develop new methods to test for water isotopes and gas fluxes in clear and precise measures. Such measures can help characterize the functioning of environmental systems such as the Biosphere 2 Rainforest Biome.

Diversity of hydrolases from hydrothermal vent sediments of the Levante Bay, Vulcano Island (Aeolian archipelago) identified by activity-based metagenomics and biochemical characterization of new esterases and an arabinopyranosidase.

PubMed

Placido, Antonio; Hai, Tran; Ferrer, Manuel; Chernikova, Tatyana N; Distaso, Marco; Armstrong, Dale; Yakunin, Alexander F; Toshchakov, Stepan V; Yakimov, Michail M; Kublanov, Ilya V; Golyshina, Olga V; Pesole, Graziano; Ceci, Luigi R; Golyshin, Peter N

2015-12-01

A metagenomic fosmid expression library established from environmental DNA (eDNA) from the shallow hot vent sediment sample collected from the Levante Bay, Vulcano Island (Aeolian archipelago) was established in Escherichia coli. Using activity-based screening assays, we have assessed 9600 fosmid clones corresponding to approximately 350 Mbp of the cloned eDNA, for the lipases/esterases/lactamases, haloalkane and haloacid dehalogenases, and glycoside hydrolases. Thirty-four positive fosmid clones were selected from the total of 120 positive hits and sequenced to yield ca. 1360 kbp of high-quality assemblies. Fosmid inserts were attributed to the members of ten bacterial phyla, including Proteobacteria, Bacteroidetes, Acidobateria, Firmicutes, Verrucomicrobia, Chloroflexi, Spirochaetes, Thermotogae, Armatimonadetes, and Planctomycetes. Of ca. 200 proteins with high biotechnological potential identified therein, we have characterized in detail three distinct α/β-hydrolases (LIPESV12_9, LIPESV12_24, LIPESV12_26) and one new α-arabinopyranosidase (GLV12_5). All LIPESV12 enzymes revealed distinct substrate specificities tested against 43 structurally diverse esters and 4 p-nitrophenol carboxyl esters. Of 16 different glycosides tested, the GLV12_5 hydrolysed only p-nitrophenol-α-(L)-arabinopyranose with a high specific activity of about 2.7 kU/mg protein. Most of the α/β-hydrolases were thermophilic and revealed a high tolerance to, and high activities in the presence of, numerous heavy metal ions. Among them, the LIPESV12_24 was the best temperature-adapted, retaining its activity after 40 min of incubation at 90 °C. Furthermore, enzymes were active in organic solvents (e.g., >30% methanol). Both LIPESV12_24 and LIPESV12_26 had the GXSXG pentapeptides and the catalytic triads Ser-Asp-His typical to the representatives of carboxylesterases of EC 3.1.1.1.

Screening and human health risk assessment of pharmaceuticals and their transformation products in Dutch surface waters and drinking water.

PubMed

de Jongh, Cindy M; Kooij, Pascal J F; de Voogt, Pim; ter Laak, Thomas L

2012-06-15

Numerous studies describe the presence of pharmaceuticals in the water cycle, while their transformation products are usually not included. In the current study 17 common pharmaceuticals and 9 transformation products were monitored in the Dutch waters, including surface waters, pre-treated surface waters, river bank filtrates, two groundwater samples affected by surface water and drinking waters. In these samples, 12 pharmaceuticals and 7 transformation products were present. Concentrations were generally highest in surface waters, intermediate in treated surface waters and river bank filtrates and lowest or not detected in produced drinking water. However, the concentrations of phenazone and its environmental transformation product AMPH were significantly higher in river bank filtrates, which is likely due to historical contamination. Fairly constant ratios were observed between concentrations of transformation products and parent pharmaceuticals. This might enable prediction of concentrations of transformation products from concentrations of parent pharmaceuticals. The toxicological relevance of the observed pharmaceuticals and transformation products was assessed by deriving (i) a substance specific provisional guideline value (pGLV) and (ii) a group pGLV for groups of related compounds were under the assumption of additivity of effects within each group. A substantial margin exists between the maximum summed concentrations of these compounds present in different water types and the derived (group) pGLVs. Based on the results of this limited screening campaign no adverse health effects of the studied compounds are expected in (sources of) drinking water in the Netherlands. The presence of transformation products with similar pharmacological activities and concentration levels as their parents illustrates the relevance of monitoring transformation products, and including these in risk assessment. More thorough monitoring yielding information on statistical uncertainty and variability in time and space, and research on possible synergistic effects of low concentration mixtures of compounds belonging to similar pharmacological classes require attention. Copyright © 2012 Elsevier B.V. All rights reserved.

Variations in the methane budget over the last two millennia

NASA Astrophysics Data System (ADS)

Derendorp, L.

2012-06-01

Leaf litter is available at the Earth’s surface in large quantities. During the decomposition of leaf litter, volatile compounds can be released into the atmosphere, where they potentially influence local air quality, atmospheric chemistry or the global climate. In this thesis the focus was on the emission of C2-C5 hydrocarbons, molecular hydrogen (H2), carbon monoxide (CO) and methyl chloride (CH3Cl) from leaf litter and the factors that control the emissions were investigated. For different plant species, the emission rates of several C2-C5 hydrocarbons increased with temperature between 20 and 100°C according to the Arrhenius relation. When leaf litter was irradiated with UV, the emission increased linearly with the intensity of the UV. UVB radiation was more efficient in the generation of hydrocarbons from leaf litter than UVA. A simple upscaling showed that C2-C5 hydrocarbon emissions from leaf litter are likely insignificant for their global budgets, but may have a small influence on atmospheric chemistry on the local scale. Senescent and dead plant material releases carbon monoxide (CO), methane and larger hydrocarbons upon heating or irradiation with UV, but emissions of hydrogen (H2) have not been reported. In this study, H2 was released from leaf litter of Sequoiadendron giganteum in detectable amounts at temperatures above 45°C, whereas CO was also emitted at ambient temperature. Leaf litter has been identified as a potentially important source of CH3Cl. However, the factors controlling the emissions are unclear. Laboratory experiments have been performed in which CH3Cl emissions were measured from leaf litter of different plant species. For each investigated plant species, the CH3Cl emission rate strongly increased with temperature according to the Arrhenius relation. However, at constant temperature, large differences between different plants were observed. Therefore, CH3Cl emissions were measured from halophyte leaf litter with a varying chloride content, but no significant correlation between the CH3Cl emission rate and the chloride content of the plant material was observed. A limited set of field experiments was performed in which CH3Cl emissions were measured. Leaf litter emitted CH3Cl, but only in periods with fresh leaf litter fall. Outside these periods, the flux from leaf litter was zero or even slightly negative. The CH3Cl emission rate increased with temperature, but the temperature increase did not follow the Arrhenius relation as was observed in the laboratory experiments. The global importance of leaf litter as a source of CH3Cl was investigated using the global chemistry transport model TM5. Forward simulations with different emission scenarios indicated that at station Trinidad Head (mid-latitudes of North America), a substantial seasonal emission from leaf litter was required to match the measured CH3Cl mixing ratios at this station. Inversions performed with the TM4-4D-Var system indicated that the main CH3Cl sources were located in the Tropics, whereas the mid- and high latitudes were only a minor source. Sensitivity studies performed to investigate the robustness of the optimized emissions indicated that more than 90% of the global net emissions was located in the Tropics.

The invasive species Alliaria petiolata (garlic mustard) increases soil nutrient availability in northern hardwood-conifer forests.

PubMed

Rodgers, Vikki L; Wolfe, Benjamin E; Werden, Leland K; Finzi, Adrien C

2008-09-01

The invasion of non-native plants can alter the diversity and activity of soil microorganisms and nutrient cycling within forests. We used field studies to analyze the impact of a successful invasive groundcover, Alliaria petiolata, on fungal diversity, soil nutrient availability, and pH in five northeastern US forests. We also used laboratory and greenhouse experiments to test three mechanisms by which A. petiolata may alter soil processes: (1) the release of volatile, cyanogenic glucosides from plant tissue; (2) the exudation of plant secondary compounds from roots; and (3) the decomposition of litter. Fungal community composition was significantly different between invaded and uninvaded soils at one site. Compared to uninvaded plots, plots invaded by A. petiolata were consistently and significantly higher in N, P, Ca and Mg availability, and soil pH. In the laboratory, the release of volatile compounds from the leaves of A. petiolata did not significantly alter soil N availability. Similarly, in the greenhouse, the colonization of native soils by A. petiolata roots did not alter soil nutrient cycling, implying that the exudation of secondary compounds has little effect on soil processes. In a leaf litter decomposition experiment, however, green rosette leaves of A. petiolata significantly increased the rate of decomposition of native tree species. The accelerated decomposition of leaf litter from native trees in the presence of A. petiolata rosette leaves shows that the death of these high-nutrient-content leaves stimulates decomposition to a greater extent than any negative effect that secondary compounds may have on the activity of the microbes decomposing the native litter. The results presented here, integrated with recent related studies, suggest that this invasive plant may change soil nutrient availability in such a way as to create a positive feedback between site occupancy and continued proliferation.

PhDAHP1 is required for floral volatile benzenoid/phenylpropanoid biosynthesis in Petunia × hybrida cv 'Mitchell Diploid'.

PubMed

Langer, Kelly M; Jones, Correy R; Jaworski, Elizabeth A; Rushing, Gabrielle V; Kim, Joo Young; Clark, David G; Colquhoun, Thomas A

2014-07-01

Floral volatile benzenoid/phenylpropanoid (FVBP) biosynthesis consists of numerous enzymatic and regulatory processes. The initial enzymatic step bridging primary metabolism to secondary metabolism is the condensation of phosphoenolpyruvate (PEP) and erythrose-4-phosphate (E4P) carried out via 3-DEOXY-D-ARABINO-HEPTULOSONATE-7-PHOSPHATE (DAHP) synthase. Here, identified, cloned, localized, and functionally characterized were two DAHP synthases from the model plant species Petunia × hybrida cv 'Mitchell Diploid' (MD). Full-length transcript sequences for PhDAHP1 and PhDAHP2 were identified and cloned using cDNA SMART libraries constructed from pooled MD corolla and leaf total RNA. Predicted amino acid sequence of PhDAHP1 and PhDAHP2 proteins were 76% and 80% identical to AtDAHP1 and AtDAHP2 from Arabidopsis, respectively. PhDAHP1 transcript accumulated to relatively highest levels in petal limb and tube tissues, while PhDAHP2 accumulated to highest levels in leaf and stem tissues. Through floral development, PhDAHP1 transcript accumulated to highest levels during open flower stages, and PhDAHP2 transcript remained constitutive throughout. Radiolabeled PhDAHP1 and PhDAHP2 proteins localized to plastids, however, PhDAHP2 localization appeared less efficient. PhDAHP1 RNAi knockdown petunia lines were reduced in total FVBP emission compared to MD, while PhDAHP2 RNAi lines emitted 'wildtype' FVBP levels. These results demonstrate that PhDAHP1 is the principal DAHP synthase protein responsible for the coupling of metabolites from primary metabolism to secondary metabolism, and the ultimate biosynthesis of FVBPs in the MD flower. Copyright © 2014 Elsevier Ltd. All rights reserved.

Airborne Signals from a Wounded Leaf Facilitate Viral Spreading and Induce Antibacterial Resistance in Neighboring Plants

PubMed Central

Dorokhov, Yuri L.; Komarova, Tatiana V.; Petrunia, Igor V.; Frolova, Olga Y.; Pozdyshev, Denis V.; Gleba, Yuri Y.

2012-01-01

Many plants release airborne volatile compounds in response to wounding due to pathogenic assault. These compounds serve as plant defenses and are involved in plant signaling. Here, we study the effects of pectin methylesterase (PME)-generated methanol release from wounded plants (“emitters”) on the defensive reactions of neighboring “receiver” plants. Plant leaf wounding resulted in the synthesis of PME and a spike in methanol released into the air. Gaseous methanol or vapors from wounded PME-transgenic plants induced resistance to the bacterial pathogen Ralstonia solanacearum in the leaves of non-wounded neighboring “receiver” plants. In experiments with different volatile organic compounds, gaseous methanol was the only airborne factor that could induce antibacterial resistance in neighboring plants. In an effort to understand the mechanisms by which methanol stimulates the antibacterial resistance of “receiver” plants, we constructed forward and reverse suppression subtractive hybridization cDNA libraries from Nicotiana benthamiana plants exposed to methanol. We identified multiple methanol-inducible genes (MIGs), most of which are involved in defense or cell-to-cell trafficking. We then isolated the most affected genes for further analysis: β-1,3-glucanase (BG), a previously unidentified gene (MIG-21), and non-cell-autonomous pathway protein (NCAPP). Experiments with Tobacco mosaic virus (TMV) and a vector encoding two tandem copies of green fluorescent protein as a tracer of cell-to-cell movement showed the increased gating capacity of plasmodesmata in the presence of BG, MIG-21, and NCAPP. The increased gating capacity is accompanied by enhanced TMV reproduction in the “receivers”. Overall, our data indicate that methanol emitted by a wounded plant acts as a signal that enhances antibacterial resistance and facilitates viral spread in neighboring plants. PMID:22496658

Plant Responses to Brief Touching: A Mechanism for Early Neighbour Detection?

PubMed

Markovic, Dimitrije; Nikolic, Neda; Glinwood, Robert; Seisenbaeva, Gulaim; Ninkovic, Velemir

2016-01-01

In natural habitats plants can be exposed to brief and light contact with neighbouring plants. This mechanical stimulus may represent a cue that induces responses to nearby plants. However, little is known about the effect of touching on plant growth and interaction with insect herbivores. To simulate contact between plants, a soft brush was used to apply light and brief mechanical stimuli to terminal leaves of potato Solanum tuberosum L. The number of non-glandular trichomes on the leaf surface was counted on images made by light microscope while glandular trichomes and pavement cells were counted on images made under scanning electronic microscope. Volatile compounds were identified and quantified using coupled gas chromatography-mass spectrometry (GC-MS). Treated plants changed their pattern of biomass distribution; they had lower stem mass fraction and higher branch and leaf mass fraction than untouched plants. Size, weight and number of tubers were not significantly affected. Touching did not cause trichome damage nor change their total number on touched terminal leaves. However, on primary leaves the number of glandular trichomes and pavement cells was significantly increased. Touching altered the volatile emission of treated plants; they released higher quantities of the sesquiterpenes (E)-β-caryophyllene, germacrene D-4-ol and (E)-nerolidol, and lower quantities of the terpenes (E)-ocimene and linalool, indicating a systemic effect of the treatment. The odour of touched plants was significantly less preferred by the aphids Macrosiphum euphorbiae and Myzus persicae compared to odour of untouched plants. The results suggest that light contact may have a potential role in the detection of neighbouring plants and may affect plant-insect interactions.

Houseplants, Indoor Air Pollutants, and Allergic Reactions

NASA Technical Reports Server (NTRS)

Wolverton, B. C.

1986-01-01

The technology of using houseplant leaves for reducing volatile organics inside closed facilities has been demonstrated with formaldehyde and benzene. Philodendrons are among the most effective plants tested to date. Philodendron domesticum had demonstrated the ability to remove formaldehyde from small experimental chambers at a rate of 4.31 micro-g/sq cm leaf surface area with initial starting concentrations of 22 ppm. At initial starting concentrations of 2.3 ppm a formaldehyde removal rate of 0.57 micro-g/sq cm was achieved during a 24 hour test. Aleo vera demonstrated a much higher formaldehyde efficiency removal rate than Philodendron domesticum at low formaldehyde concentrations. During a 24 hour exposure period 5 ppm of formaldehyde were reduced to 0.5 ppm demonstrating a removal efficiency rate of 3.27 micro-g/sq cm. Removal efficiency rates can be expected to decrease with concentration levels because fewer molecules of chemicals come in contact with the leaf surface area. Several centimeters of small washed gravel should be used to cover the surface of pot plants when large numbers of plants are kept in the home. The reason for this is to reduce the exposed area of damp potting soil which encourages the growth of molds (fungi). The leaves of Philodendron domesticum and golden pothos (Scindapsus aureus) have also demonstrated their ability to remove benzene and carbon monoxide from closed chambers. A combination of activated carbon and plant roots have demonstrated the greatest potential for removing large volumes of volatile organics along with smoke and possible radon from closed systems. Although fewer plants are required for this concept a mechanical blower motor must be used to pull or push the air through the carbon-root filter. NASA studies on motor sizes and bioregeneration rates should be completed by 1988.

Plant Responses to Brief Touching: A Mechanism for Early Neighbour Detection?

PubMed Central

Markovic, Dimitrije; Nikolic, Neda; Glinwood, Robert; Seisenbaeva, Gulaim; Ninkovic, Velemir

2016-01-01

In natural habitats plants can be exposed to brief and light contact with neighbouring plants. This mechanical stimulus may represent a cue that induces responses to nearby plants. However, little is known about the effect of touching on plant growth and interaction with insect herbivores. To simulate contact between plants, a soft brush was used to apply light and brief mechanical stimuli to terminal leaves of potato Solanum tuberosum L. The number of non-glandular trichomes on the leaf surface was counted on images made by light microscope while glandular trichomes and pavement cells were counted on images made under scanning electronic microscope. Volatile compounds were identified and quantified using coupled gas chromatography–mass spectrometry (GC-MS). Treated plants changed their pattern of biomass distribution; they had lower stem mass fraction and higher branch and leaf mass fraction than untouched plants. Size, weight and number of tubers were not significantly affected. Touching did not cause trichome damage nor change their total number on touched terminal leaves. However, on primary leaves the number of glandular trichomes and pavement cells was significantly increased. Touching altered the volatile emission of treated plants; they released higher quantities of the sesquiterpenes (E)-β-caryophyllene, germacrene D-4-ol and (E)-nerolidol, and lower quantities of the terpenes (E)-ocimene and linalool, indicating a systemic effect of the treatment. The odour of touched plants was significantly less preferred by the aphids Macrosiphum euphorbiae and Myzus persicae compared to odour of untouched plants. The results suggest that light contact may have a potential role in the detection of neighbouring plants and may affect plant-insect interactions. PMID:27828995

Products derived from olive leaves and fruits can alter in vitro ruminal fermentation and methane production.

PubMed

Shakeri, Pirouz; Durmic, Zoey; Vadhanabhuti, Joy; Vercoe, Philip E

2017-03-01

The industrial processing of olive generates a high quantity of by-products. The objective of this study was to examine the effects of products derived from olive trees, i.e. leaves, fruits or kernels as a sole substrate (part A), and crude extract from leaves combined with a substrate (part B) on rumen microbial fermentation in an in vitro batch fermentation system. In this study, total gas production, methane production, and concentrations of volatile fatty acids (VFA) and ammonia in ruminal fluid were measured. In part A, in vitro fermentation of leaves or fruits yielded a gas and total VFA production that were comparable with control substrate, while most of them produced significantly less methane (up to 55.6%) when compared to control substrate. In part B, amongst leaf extracts, only addition of chloroform extract reduced methane production, which was also associated with a decrease (P < 0.01) in gas production. This effect was associated with a significant reduction (P < 0.01) in acetate to propionate ratio and ammonia production, but not in reduction in VFA concentrations. Olive leaf and olive leaf chloroform extract reduced ammonia production and increased the molar proportion of propionate in the rumen and can assist in developing novel feed additives for methane mitigation from the rumen. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Microalgae biofilm in soil: Greenhouse gas emissions, ammonia volatilization and plant growth.

PubMed

Castro, Jackeline de Siqueira; Calijuri, Maria Lúcia; Assemany, Paula Peixoto; Cecon, Paulo Roberto; de Assis, Igor Rodrigues; Ribeiro, Vinícius José

2017-01-01

Microalgal biofilm in soils represents an alternative fertilization method for agricultural sustainability. In the present study, greenhouse gas emission, soil ammonia volatilization, and the growth of Pennisetum glaucum were evaluated under the effect of a microalgal biofilm, commercial urea, and a control (without application of a nitrogen source). CH 4 emissions were equal for the three treatments (p>0.05). CO 2 emissions significantly increased in microalgal biofilm treatment (p<0.01), which was also responsible for the highest N 2 O emissions (p<0.01). The ammonia (NNH 3 ) volatilization losses were 4.63%, 18.98%, and 0.82% for the microalgal biofilm, urea, and control treatments, respectively. The main differences in soil characteristics were an increase in nitrogen and an increase in cation exchange capacity (p<0.01) caused by the algal biomass application to the soil. The soil organic matter content significantly differed (p<0.05) among the three treatments, with the microalgal biofilm treatment having the greatest increase in soil organic matter. Significant differences were observed for shoot dry matter mass and nitrogen content in the plants from both treatments where nitrogen sources were applied. All treatments differed from each other in leaf dry matter mass, with the urea treatment increasing the most. Chlorella vulgaris was the dominant microalgal specie in the soil. Copyright © 2016 Elsevier B.V. All rights reserved.

Antimicrobial activity of endophytic fungi from olive tree leaves.

PubMed

Malhadas, Cynthia; Malheiro, Ricardo; Pereira, José Alberto; de Pinho, Paula Guedes; Baptista, Paula

2017-03-01

In this study, the antimicrobial potential of three fungal endophytes from leaves of Olea europaea L. was evaluated and the host plant extract effect in the antimicrobial activity was examined. The volatile compounds produced by endophytes were identified by GC/MS and further correlated with the antimicrobial activity. In potato dextrose agar, both Penicillium commune and Penicillium canescens were the most effective inhibiting Gram-positive and -negative bacteria (up to 2.7-fold compared to 30 µg/mL chloramphenicol), whereas Alternaria alternata was most effective inhibiting yeasts (up to 8.0-fold compared to 25 μg/mL fluconazole). The presence of aqueous leaf extract in culture medium showed to induce or repress the antimicrobial activity, depending on the endophytic species. In the next step, various organic extracts from both A. alternata mycelium and cultured broth were prepared; being ethyl acetate extracts displayed the widest spectrum of anti-microorganisms at a minimum inhibitory concentration ≤0.095 mg/mL. The volatile composition of the fungi that displayed the highest (A. alternata) and the lowest (P. canescens) antimicrobial activity against yeasts revealed the presence of six volatiles, being the most abundant components (3-methyl-1-butanol and phenylethyl alcohol) ascribed with antimicrobial potentialities. Overall the results highlighted for the first time the antimicrobial potential of endophytic fungi from O. europaea and the possibility to be exploited for their antimicrobial agents.

Diurnal Pattern of Leaf, Flower and Fruit Specific Ambient Volatiles above an Oil Palm Plantation in Pará State, Brazil

DOE PAGES

Jardine, Kolby J.; Gimenez, Bruno O.; Araujo, Alessandro C.; ...

2016-01-01

Oil palm plantations are rapidly expanding in the tropics because of insatiable global demand for fruit oil to be used in food, biofuels and cosmetics. Here we show that three tissue-specific volatiles can be quantified in ambient air above an African-American hybrid oil palm plantation in Brazil and linked photosynthesis (isoprene), floral scent (estragole), and for the first time, fruit oil processing (6-methyl-5-hepten-2-one, MHO). Plant enclosure techniques verified their tissue specific emission sources with ambient concentrations displaying distinct diurnal patterns above the canopy. Isoprene concentrations were near zero at night, but dramatically increased during the day while estragole showed elevatedmore » concentrations at night suggesting a light-independent, temperature-driven emission pattern from flowers. MHO also showed elevated concentrations at night and both estragole and MHO increased during the day. Our observations demonstrate that the African-American oil palm hybrid is strong isoprene emitter and suggest that MHO is a specific oxidation product of lycopene released during the industrial processing of palm oil. This study highlights the potential value of quantifying volatile oil palm signals in the atmosphere as a novel, non-invasive method to better understand biological functioning and its interactions with the environment including carbon assimilation, floral-insect interactions, and fruit oil production/processing.« less

Diurnal Pattern of Leaf, Flower and Fruit Specific Ambient Volatiles above an Oil Palm Plantation in Pará State, Brazil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jardine, Kolby J.; Gimenez, Bruno O.; Araujo, Alessandro C.

Oil palm plantations are rapidly expanding in the tropics because of insatiable global demand for fruit oil to be used in food, biofuels and cosmetics. Here we show that three tissue-specific volatiles can be quantified in ambient air above an African-American hybrid oil palm plantation in Brazil and linked photosynthesis (isoprene), floral scent (estragole), and for the first time, fruit oil processing (6-methyl-5-hepten-2-one, MHO). Plant enclosure techniques verified their tissue specific emission sources with ambient concentrations displaying distinct diurnal patterns above the canopy. Isoprene concentrations were near zero at night, but dramatically increased during the day while estragole showed elevatedmore » concentrations at night suggesting a light-independent, temperature-driven emission pattern from flowers. MHO also showed elevated concentrations at night and both estragole and MHO increased during the day. Our observations demonstrate that the African-American oil palm hybrid is strong isoprene emitter and suggest that MHO is a specific oxidation product of lycopene released during the industrial processing of palm oil. This study highlights the potential value of quantifying volatile oil palm signals in the atmosphere as a novel, non-invasive method to better understand biological functioning and its interactions with the environment including carbon assimilation, floral-insect interactions, and fruit oil production/processing.« less

Canopy light cues affect emission of constitutive and methyl jasmonate-induced volatile organic compounds in Arabidopsis thaliana.

PubMed

Kegge, Wouter; Weldegergis, Berhane T; Soler, Roxina; Vergeer-Van Eijk, Marleen; Dicke, Marcel; Voesenek, Laurentius A C J; Pierik, Ronald

2013-11-01

The effects of plant competition for light on the emission of plant volatile organic compounds (VOCs) were studied by investigating how different light qualities that occur in dense vegetation affect the emission of constitutive and methyl-jasmonate-induced VOCs. Arabidopsis thaliana Columbia (Col-0) plants and Pieris brassicae caterpillars were used as a biological system to study the effects of light quality manipulations on VOC emissions and attraction of herbivores. VOCs were analysed using gas chromatography-mass spectrometry and the effects of light quality, notably the red : far red light ratio (R : FR), on expression of genes associated with VOC production were studied using reverse transcriptase-quantitative PCR. The emissions of both constitutive and methyl-jasmonate-induced green leaf volatiles and terpenoids were partially suppressed under low R : FR and severe shading conditions. Accordingly, the VOC-based preference of neonates of the specialist lepidopteran herbivore P. brassicae was significantly affected by the R : FR ratio. We conclude that VOC-mediated interactions among plants and between plants and organisms at higher trophic levels probably depend on light alterations caused by nearby vegetation. Studies on plant-plant and plant-insect interactions through VOCs should take into account the light quality within dense stands when extrapolating to natural and agricultural field conditions. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Doxycycline Inducible Melanogenic Vaccinia Virus as Theranostic Anti-Cancer Agent.

PubMed

Kirscher, Lorenz; Deán-Ben, Xosé Luis; Scadeng, Miriam; Zaremba, Angelika; Zhang, Qian; Kober, Christina; Fehm, Thomas Felix; Razansky, Daniel; Ntziachristos, Vasilis; Stritzker, Jochen; Szalay, Aladar A

2015-01-01

We reported earlier the diagnostic potential of a melanogenic vaccinia virus based system in magnetic resonance (MRI) and optoacoustic deep tissue imaging (MSOT). Since melanin overproduction lead to attenuated virus replication, we constructed a novel recombinant vaccinia virus strain (rVACV), GLV-1h462, which expressed the key enzyme of melanogenesis (tyrosinase) under the control of an inducible promoter-system. In this study melanin production was detected after exogenous addition of doxycycline in two different tumor xenograft mouse models. Furthermore, it was confirmed that this novel vaccinia virus strain still facilitated signal enhancement as detected by MRI and optoacoustic tomography. At the same time we demonstrated an enhanced oncolytic potential compared to the constitutively melanin synthesizing rVACV system.

Differential mercury volatilization by tobacco organs expressing a modified bacterial merA gene.

PubMed

He, Y K; Sun, J G; Feng, X Z; Czakó, M; Márton, L

2001-09-01

Mercury pollution is a major environmental problem accompanying industrial activities. Most of the mercury released ends up and retained in the soil as complexes of the toxic ionic mercury (Hg2+), which then can be converted by microbes into the even more toxic methylmercury which tends to bioaccumulate. Mercury detoxification of the soil can also occur by microbes converting the ionic mercury into the least toxic metallic mercury (Hg0) form, which then evaporates. The remediation potential of transgenic plants carrying the MerA gene from E. coli encoding mercuric ion reductase could be evaluated. A modified version of the gene, optimized for plant codon preferences (merApe9, Rugh et al. 1996), was introduced into tobacco by Agrobacterium-mediated leaf disk transformation. Transgenic seeds were resistant to HgCl2 at 50 microM, and some of them (10-20% ) could germinate on media containing as much as 350 microM HgCl2, while the control plants were fully inhibited or died on 50 microM HgCl2. The rate of elemental mercury evolution from Hg2+ (added as HgCl2) was 5-8 times higher for transgenic plants than the control. Mercury volatilization by isolated organs standardized for fresh weight was higher (up to 5 times) in the roots than in shoots or the leaves. The data suggest that it is the root system of the transgenic plants that volatilizes most of the reduced mercury (Hg0). It also suggests that much of the mercury need not enter the vascular system to be transported to the leaves for volatilization. Transgenic plants with the merApe9 gene may be used to mercury detoxification for environmental improvement in mercury-contaminated regions more efficiently than it had been predicted based on data on volatilization of whole plants via the upper parts only (Rugh et al. 1996).

Electrophysiological Responses and Reproductive Behavior of Fall Webworm Moths (Hyphantria cunea Drury) are Influenced by Volatile Compounds from Its Mulberry Host (Morus alba L.)

PubMed Central

Tang, Rui; Zhang, Feng; Zhang, Zhong-Ning

2016-01-01

Hyphantria cunea (Drury) is an invasive pest of Morus alba L. in China. β-ocimene and cis-2-penten-1-ol among eleven electro-physiologically active leaf volatiles from M. alba have been reported to influence captures of Hyphantria cunea moths when added into sex pheromone traps. This study further investigated influences of volatile types and their dosages on the electro-physiological responses in the antennae of male and female moths, as well as on mating and oviposition behaviors. Females were, regardless of dosages, more sensitive to β-ocimene and cis-2-penten-1-ol in electro-physiological response tests than males. For males, a dose response was detected, i.e., a dosage of 10 μg and 100 μg of either chemical stimulated higher electric response in their antennae than 1 μg. Moth pairs either exposed respectively to a herbivore-induced M. alba volatile blend (HIPV), to a mechanically-damaged M. alba volatile blend (MDV), to β-ocimene, to cis-2-penten-1-ol, or to pentane as a control showed that pairs exposed to β-ocimene most likely mated, followed by HIPV blends and least by the other volatiles or the control. In contrast, β-ocimene induced about 70% of the female oviposition behaviors and was nearly 4.5 times the oviposition rate than cis-2-penten-1-ol and 2 times than the control. However, none of the chemicals had any effect on the 48 h fecundity or on egg sizes. In conclusion, β-ocimene from mulberry plants alone could promote mating and oviposition in H. cunea at a dosage of 1 mg. The results indicate that reproductive behaviors of H. cunea moths can be enhanced through HIPV blends and β-ocimene induced by feeding of larvae. This contra phenomenon has revealed a different ecology in this moth during colonizing China as local pests would commonly be repelled by herbivore induced chemicals. These chemicals can be used for the development of biological control approaches such as being used together with sex pheromone traps. PMID:27153095

Electrophysiological Responses and Reproductive Behavior of Fall Webworm Moths (Hyphantria cunea Drury) are Influenced by Volatile Compounds from Its Mulberry Host (Morus alba L.).

PubMed

Tang, Rui; Zhang, Feng; Zhang, Zhong-Ning

2016-05-03

Hyphantria cunea (Drury) is an invasive pest of Morus alba L. in China. β-ocimene and cis-2-penten-1-ol among eleven electro-physiologically active leaf volatiles from M. alba have been reported to influence captures of Hyphantria cunea moths when added into sex pheromone traps. This study further investigated influences of volatile types and their dosages on the electro-physiological responses in the antennae of male and female moths, as well as on mating and oviposition behaviors. Females were, regardless of dosages, more sensitive to β-ocimene and cis-2-penten-1-ol in electro-physiological response tests than males. For males, a dose response was detected, i.e., a dosage of 10 μg and 100 μg of either chemical stimulated higher electric response in their antennae than 1 μg. Moth pairs either exposed respectively to a herbivore-induced M. alba volatile blend (HIPV), to a mechanically-damaged M. alba volatile blend (MDV), to β-ocimene, to cis-2-penten-1-ol, or to pentane as a control showed that pairs exposed to β-ocimene most likely mated, followed by HIPV blends and least by the other volatiles or the control. In contrast, β-ocimene induced about 70% of the female oviposition behaviors and was nearly 4.5 times the oviposition rate than cis-2-penten-1-ol and 2 times than the control. However, none of the chemicals had any effect on the 48 h fecundity or on egg sizes. In conclusion, β-ocimene from mulberry plants alone could promote mating and oviposition in H. cunea at a dosage of 1 mg. The results indicate that reproductive behaviors of H. cunea moths can be enhanced through HIPV blends and β-ocimene induced by feeding of larvae. This contra phenomenon has revealed a different ecology in this moth during colonizing China as local pests would commonly be repelled by herbivore induced chemicals. These chemicals can be used for the development of biological control approaches such as being used together with sex pheromone traps.

Comparable Monoterpene emission from pine forests across 500 mm precipitation gradient in the semi-arid transition zone

NASA Astrophysics Data System (ADS)

Seco, Roger; Karl, Thomas; Turnipseed, Andrew; Greenberg, Jim; Guenther, Alex; Llusia, Joan; Penuelas, Josep; Dicken, Uri; Rotenberg, Eyal; Rohatyn, Shani; Preisler, Yakir; Yakir, Dan

2014-05-01

Atmospheric volatile organic compounds (VOCs) have key environmental and biological roles, and can affect atmospheric chemistry, secondary aerosol formation, and as a consequence also climate. At the same time, global changes in climate arising from human activities can modify the VOC emissions of vegetation in the coming years. Monoterpene emission fluxes were measured during April 2013 at two forests in the semi-arid climate of Israel. Both forests were dominated by Pinus halepensis trees of similar age, but differed in the amount of annual average precipitation received (~276 and ~760 mm at the Yatir and Birya sites, respectively). Measurements performed included leaf-level sampling and gas exchange, as well as canopy-level flux calculations. Leaf level monoterpene emissions were sampled from leaf cuvettes with adsorbent cartridges and later analyzed by GC-MS. Canopy scale fluxes were calculated with the Disjunct Eddy Covariance technique by means of a Quadrupole PTRMS and eddy-covariance system. We report the differences observed between the two forests in terms of photosynthetic activity and monoterpene emissions, aiming to see the effect of the different climatic regimes at each location. Significantly higher emission rates of monoterpenes were observed in the wetter site during mid-day, in both the leaf scale and canopy scale measurements. Remarkably, however, normalized to 30C and corrected for tree density differences between the sites indicated comparable emission rates for both sites, with higher emission rated in the evening hours in the dry site at the edge of the Negev Desert. Modeling the monoterpene emission rates using MEGAN v2.1 indicated better agreement with observations in the wetter site then in the dry site, especially with respect to fluxes during the evening hours.

Identifying the environmental factors that effect within canopy BVOC loss using a multilevel canopy model

NASA Astrophysics Data System (ADS)

Chan, W. S.; Fuentes, J. D.; Lerdau, M.

2010-12-01

This presentation will provide research findings to evaluate the hypothesis that the loss of biogenic volatile organic compound (BVOC) within plant canopies is dynamic and depends on factors such as plant canopy architecture (height and leaf area distribution), atmospheric turbulence, concentration of oxidants (OH, O3, NO3), and the reactivity of BVOC species. Results will be presented from a new one dimensional, multilevel canopy model that couples algorithms for canopy microclimate, leaf physiology, BVOC emission, turbulent transport, and atmospheric chemistry to investigate the relative importance of factors that impact BVOC loss within a forest canopy. Model sensitivity tests will be presented and discussed to identify factors driving canopy loss. Results show isoprene and monoterpene canopy losses as high as 9 and 18%, respectively, for tall canopies during the daytime. We hypothesize that canopy height and wind speed (i.e. canopy residence time) may be the most important in dictating within-canopy loss. This work will reduce the error in bottom-up flux estimates of BVOCs and ultimately improve parameterizations of BVOC sources in air quality models by accounting for within canopy processes.

Volatile aldehydes are promising broad-spectrum postharvest insecticides.

PubMed

Hammond, D G; Rangel, S; Kubo, I

2000-09-01

A variety of naturally occurring aldehydes common in plants have been evaluated for their insecticidal activity and for phytotoxicity to postharvest fruits, vegetables, and grains. Twenty-nine compounds were initially screened for their activity against aphids on fava bean leaf disks. Application under reduced pressure (partial vacuum) for the first quarter of fumigation increased insecticidal activity severalfold. The 11 best aldehydes were assayed against aphids placed under the third leaf of whole heads of iceberg lettuce using the same two-tier reduced-pressure regime, which caused no additional detriment to the commodity over fumigation at atmospheric pressure. Phytotoxicity to naked and wrapped iceburg lettuce, green and red table grapes, lemon, grapefruit, orange, broccoli, avocado, cabbage, pinto bean, and rice at doses that killed 100% of aphids was recorded for three promising fumigants: propanal, (E)-2-pentenal, and 2-methyl-(E)-2-butenal. These three compounds have excellent potential as affordable postharvest insect control agents, killing 100% of the aphids with little or no detectable harm to a majority of the commodities tested. Preliminary assays indicate that similar doses are also effective against mealybugs, thrips, and whitefly.

Uptake of aldehydes and ketones at typical indoor concentrations by houseplants.

PubMed

Tani, Akira; Hewitt, C Nicholas

2009-11-01

The uptake rates of low-molecular weight aldehydes and ketones by peace lily (Spathiphyllum clevelandii) and golden pothos (Epipremnum aureum) leaves at typical indoor ambient concentrations (10(1)-10(2) ppbv) were determined. The C3-C6 aldehydes and C4-C6 ketones were taken up by the plant leaves, but the C3 ketone acetone was not. The uptake rate normalized to the ambient concentration C(a) ranged from 7 to 19 mmol m(-2) s(-1) and from 2 to 7 mmol m(-2) s(-1) for the aldehydes and ketones, respectively. Longer-term fumigation results revealed that the total uptake amounts were 30-100 times as much as the amounts dissolved in the leaf, suggesting that volatile organic carbons are metabolized in the leaf and/or translocated through the petiole. The ratio of the intercellular concentration to the external (ambient) concentration (C(i)/C(a)) was significantly lower for most aldehydes than for most ketones. In particular, a linear unsaturated aldehyde, crotonaldehyde, had a C(i)/C(a) ratio of approximately 0, probably because of its highest solubility in water.

Constitutive polymorphic cyanogenesis in the Australian rainforest tree, Ryparosa kurrangii (Achariaceae).

PubMed

Webber, Bruce L; Miller, Rebecca E; Woodrow, Ian E

2007-08-01

Cyanogenesis, the liberation of volatile hydrogen cyanide from endogenous cyanide-containing compounds, is a proven plant defence mechanism and the particular cyanogens involved have taxonomic utility. The cyclopentenoncyanhydrin glycoside gynocardin was the only cyanogen isolated from foliar tissue of the rare Australian rainforest tree, Ryparosa kurrangii (Achariaceae). Mechanical damage simulating foliar herbivory did not induce a significant increase in the expression of cyanogenesis over a 24h period, indicating cyanogenic herbivore defence in R. kurrangii is constitutive. The cyanogenic potential of mature leaves was quantitatively polymorphic between trees in a natural population, ranging from 0.54 to 4.77 mg CN g(-1) dry wt leaf tissue.

Foraging behavior of the dead leaf butterfly, Kallima inachus.

PubMed

Tang, Yuchong; Zhou, Chengli; Chen, Xiaoming; Zheng, Hua

2013-01-01

The behavioral responses of foraging adults of Kallima inachus (Boisduval) (Lepidoptera: Nymphalidae) to four colors and to six different fermented fruit juices were observed in order to determine the cues used by foraging adults. According to the results, adults did not show a behavioral response to red, yellow, purple, or white artificial flowers without food odors, but flowers with the fermented pear juice strongly attracted them, and they showed a behavioral response to fermented juices of the six fruits (pear, apple, banana, watermelon, orange, and persimmon) with no statistically significant preference. The fruit volatiles were collected using dynamic headspace adsorption, and the volatile components were analyzed by auto thermal-desorption gas chromatography-mass spectrometry to assess which volatiles existed in the fruits. Only alcohols, esters, and ketones were common in the volatiles of all six fermenting fruits. The five volatile components found in the six fruits, as well as two others found to be in other fermented foods by previous studies, were selected to test the behavioral and electroantennogram (EAG) responses of naive adults to estimate behavioral preference and antennal perception. In field behavioral tests, alcohols were the most attractive, followed by esters, while α-pinene, butanone, and acetic acid were much less attractive. Relative to other volatile combinations and ethanol alone, the mixture of ethyl acetate and ethanol attracted the most feeding adults. The number of adults attracted was significantly positively correlated with the concentration of both ethanol and ethyl acetate. The EAG responses of naive adults showed that the EAG responses to 3-methyl-1-butanol, isoamyl acetate, ethyl acetate, α-pinene, butanone, and acetic acid were all higher than those to ethanol (100%) at doses of either 5 µl/mL or 50 µl/mL. Sexual differences only existed in 3-methyl-1-butanol and acetic acid at particular concentrations. Sexual differences in response to chemical mixtures were not significant at 50 µl/mL. In addition, the EAG responses in the within-sex trials were not correlated to the dosage (0.01, 0.1, 1, 5, 10, and µl/mL) of either ethanol or ethyl acetate. The results showed that olfactory cues played a crucial role in the foraging of adult K. inachus, and that foraging adults can use a variety of chemical signals derived from food; however, the feeding preference to volatiles was not necessary correlated with the EAG responses.

Molecular differentiation of five Cinnamomum camphora chemotypes using desorption atmospheric pressure chemical ionization mass spectrometry of raw leaves

PubMed Central

Guo, Xiali; Cui, Meng; Deng, Min; Liu, Xingxing; Huang, Xueyong; Zhang, Xinglei; Luo, Liping

2017-01-01

Five chemotypes, the isoborneol-type, camphora-type, cineole-type, linalool-type and borneol-type of Cinnamomum camphora (L.) Presl have been identified at the molecular level based on the multivariate analysis of mass spectral fingerprints recorded from a total of 750 raw leaf samples (i.e., 150 leaves equally collected for each chemotype) using desorption atmospheric pressure chemical ionization mass spectrometry (DAPCI-MS). Both volatile and semi-volatile metabolites of the fresh leaves of C. camphora were simultaneously detected by DAPCI-MS without any sample pretreatment, reducing the analysis time from half a day using conventional methods (e.g., GC-MS) down to 30 s. The pattern recognition results obtained using principal component analysis (PCA) was cross-checked by cluster analysis (CA), showing that the difference visualized by the DAPCI-MS spectral fingerprints was validated with 100% accuracy. The study demonstrates that DAPCI-MS meets the challenging requirements for accurate differentiation of all the five chemotypes of C. camphora leaves, motivating more advanced application of DAPCI-MS in plant science and forestry studies. PMID:28425482

Encountering epidemic effects of leaf spot disease (Alternaria brassicae) on Aloe vera by fungal biocontrol agents in agrifields-An ecofriendly approach.

PubMed

Ghosh, Swapan Kumar; Banerjee, Subhankar; Pal, Sujoy; Chakraborty, Niloy

2018-01-01

Aloe vera (L.) Burm.f. is a highly important and extensively cultivated medicinal plant and that is also extensively used in the cosmetic industry. It has been frequently reported to suffer from Alternaria leaf spot disease in various parts of the world. Various fungicides used to combat this disease, have deleterious effects on the environment and on pharmacologically important constituents of Aloe vera. To avoid the harmful effects of fungicides an ecofriendly approach has been adopted here. A weekly survey was conducted during 2013-2015 in and around North 24 Parganas (West Bengal) to obtain the percentage of disease index (PDI). For biological control of the disease, screening of the antagonistic efficacy of biocontrol agents was carried out through the in vitro dual-culture-plate method and scanning electron microscopy (SEM) was used to study the mechanism. The in vitro effects of fungicides on the radial growth of the pathogen were evaluated through the poison food method and were compared with potent antagonistic fungi. Field application of potent antagonistic fungi was conducted through the dip-and-spray method. The results showed that, the PDI peaked during the hot and humid conditions of May to September (76.57%-98.57%) but decreased during the winter, December-January (35.71-46.66%). Trichoderma asperellum exerted the greatest inhibition of the radial growth of A. brassicae acting through non volatile (70.39%) and volatile metabolites (72.17%). A SEM study confirmed the hyperparasitic nature of T. asperellum through hyphal coiling-T. asperellum was similar to 2% blitox-50 (73.92%) and better than 2% bavistin (59.77%) (in vitro). In agricultural field trials (2013-15), Trichoderma application restricted the disease to the smallest area (PDI 24.00-29.33%) in comparison to untreated plots (73.33%). In conclusion, saplings treated with the dip method (108 spores / mL) and sprayed 4 times with a spore suspension of biocontrol agents such as T. asperellum, T. viride and T. harzianum, standardized at a rate of 2.5 L / plot (36 sq ft) (108 spores/ mL) are suggested for the ecofriendly management of this epidemic leaf spot disease of Aloe vera in agricultural fields.

Encountering epidemic effects of leaf spot disease (Alternaria brassicae) on Aloe vera by fungal biocontrol agents in agrifields—An ecofriendly approach

PubMed Central

Banerjee, Subhankar; Pal, Sujoy; Chakraborty, Niloy

2018-01-01

Aloe vera (L.) Burm.f. is a highly important and extensively cultivated medicinal plant and that is also extensively used in the cosmetic industry. It has been frequently reported to suffer from Alternaria leaf spot disease in various parts of the world. Various fungicides used to combat this disease, have deleterious effects on the environment and on pharmacologically important constituents of Aloe vera. To avoid the harmful effects of fungicides an ecofriendly approach has been adopted here. A weekly survey was conducted during 2013–2015 in and around North 24 Parganas (West Bengal) to obtain the percentage of disease index (PDI). For biological control of the disease, screening of the antagonistic efficacy of biocontrol agents was carried out through the in vitro dual-culture-plate method and scanning electron microscopy (SEM) was used to study the mechanism. The in vitro effects of fungicides on the radial growth of the pathogen were evaluated through the poison food method and were compared with potent antagonistic fungi. Field application of potent antagonistic fungi was conducted through the dip-and-spray method. The results showed that, the PDI peaked during the hot and humid conditions of May to September (76.57%–98.57%) but decreased during the winter, December-January (35.71–46.66%). Trichoderma asperellum exerted the greatest inhibition of the radial growth of A. brassicae acting through non volatile (70.39%) and volatile metabolites (72.17%). A SEM study confirmed the hyperparasitic nature of T. asperellum through hyphal coiling-T. asperellum was similar to 2% blitox-50 (73.92%) and better than 2% bavistin (59.77%) (in vitro). In agricultural field trials (2013–15), Trichoderma application restricted the disease to the smallest area (PDI 24.00–29.33%) in comparison to untreated plots (73.33%). In conclusion, saplings treated with the dip method (108 spores / mL) and sprayed 4 times with a spore suspension of biocontrol agents such as T. asperellum, T. viride and T. harzianum, standardized at a rate of 2.5 L / plot (36 sq ft) (108 spores/ mL) are suggested for the ecofriendly management of this epidemic leaf spot disease of Aloe vera in agricultural fields. PMID:29579070

Molecular characterization of polar organosulfates in secondary organic aerosol from the green leaf volatile 3-Z-hexenal

NASA Astrophysics Data System (ADS)

Safi Shalamzari, Mohammad; Kahnt, Ariane; Wang, Wu; Vermeylen, Reinhilde; Kleindienst, Tadeusz; Lewandovski, Michael; Maenhaut, Willy; Claeys, Magda

2014-05-01

Much information is available about secondary organic aerosol (SOA) formation from terpenes, including mono- and sesquiterpenes, and isoprene. However, information about SOA formation from green leaf volatiles (GLVs), an important class of biogenic volatile organic compounds, which are emitted when plants are wounded or attacked by insects, is very scarce. In the present study, we provide evidence that 3-Z-hexenal is a potential precursor for SOA through formation of organosulfates. Organosulfate formation from 3-Z-hexenal was studied by conducting smog chamber photooxidation experiments in the presence of NO and acidic ammonium seed aerosol, where OH radicals were generated from the NOx mediated photochemical chain reactions. The focus of the study was on the structural characterization of products, i.e., organosulfates (OSs) with a molecular weight (MW) of 226, which are also present in ambient fine aerosol from a forested site (K puszta, Hungary) at a substantial relative abundance that is comparable to that of the MW 216 isoprene-related OSs. Polar OSs are of climatic relevance because of their capacity to increase the hydrophilic properties of aerosols and as such their cloud-condensation nuclei effects. Two different liquid chromatography (LC) techniques were employed to separate the polar OSs: the first technique uses a reversed-phase trifunctionally bonded C18 stationary phase, whereas the second one is based on ion-pairing C18 LC using dibutylammonium acetate as ion-pairing reagent. With regard to mass spectrometry (MS) techniques, use was made of high-resolution MS to determine the accurate mass (measured mass, 225.00809; elemental composition, C6H9O7S) as well as linear ion trap MS to obtain detailed structural information. The MW 226 OSs were structurally characterized as sulfated derivatives of 3,4-dihydroxyhex-2-enoic acid with the sulfate group positioned at C-3 or C-4. The formation of these OSs is explained through photooxidation in the gas phase resulting in a hydroperoxide, followed by acid-catalyzed rearrangement into an epoxyhydroxide and subsequent sulfation of the epoxy group in the particle phase. This work was supported by the Belgian Federal Science Policy Office through the network project "Biogenic Influence on Oxidants and Secondary Organic Aerosol: theoretical, laboratory and modeling investigations (BIOSOA)" and the Research Foundation - Flanders (FWO).

Continuous exposure to the deterrents cis-jasmone and methyl jasmonate does not alter the behavioural responses of Frankliniella occidentalis

PubMed Central

Egger, Barbara; Spangl, Bernhard; Koschier, Elisabeth Helene

2016-01-01

Behavioural responses of Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), a generalist, cell sap-feeding insect species with piercing-sucking mouthparts, after continuous exposure to two deterrent secondary plant compounds are investigated. We compared in choice assays on bean leaf discs, the settling, feeding, and oviposition preferences of F. occidentalis females that had no experience with the two fatty acid derivatives methyl jasmonate and cis-jasmone before testing (naïve thrips) vs. females that had been exposed to the deterrent compounds before testing (experienced thrips). The thrips were exposed to the deterrents at low or high concentrations for varied time periods and subsequently tested on bean leaf discs treated with the respective deterrent at either a low or a high concentration. Frankliniella occidentalis females avoided settling on the deterrent-treated bean leaf discs for an observation period of 6 h, independent of their previous experience. Our results demonstrate that feeding and oviposition deterrence of the jasmonates to the thrips were not altered by continuous exposure of the thrips to the jasmonates. Habituation was not induced, neither by exposure to the low concentration of the deterrents nor by exposure to the high concentration. These results indicate that the risk of habituation to two volatile deterrent compounds after repeated exposure is not evident in F. occidentalis. This makes the two compounds potential candidates to be integrated in pest management strategies. PMID:26726263

Continuous exposure to the deterrents cis-jasmone and methyl jasmonate does not alter the behavioural responses of Frankliniella occidentalis.

PubMed

Egger, Barbara; Spangl, Bernhard; Koschier, Elisabeth Helene

2016-01-01

Behavioural responses of Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), a generalist, cell sap-feeding insect species with piercing-sucking mouthparts, after continuous exposure to two deterrent secondary plant compounds are investigated. We compared in choice assays on bean leaf discs, the settling, feeding, and oviposition preferences of F. occidentalis females that had no experience with the two fatty acid derivatives methyl jasmonate and cis -jasmone before testing (naïve thrips) vs. females that had been exposed to the deterrent compounds before testing (experienced thrips). The thrips were exposed to the deterrents at low or high concentrations for varied time periods and subsequently tested on bean leaf discs treated with the respective deterrent at either a low or a high concentration. Frankliniella occidentalis females avoided settling on the deterrent-treated bean leaf discs for an observation period of 6 h, independent of their previous experience. Our results demonstrate that feeding and oviposition deterrence of the jasmonates to the thrips were not altered by continuous exposure of the thrips to the jasmonates. Habituation was not induced, neither by exposure to the low concentration of the deterrents nor by exposure to the high concentration. These results indicate that the risk of habituation to two volatile deterrent compounds after repeated exposure is not evident in F. occidentalis . This makes the two compounds potential candidates to be integrated in pest management strategies.

Comparative study on ambient ionization methods for direct analysis of navel orange tissues by mass spectrometry.

PubMed

Zhang, Hua; Bibi, Aisha; Lu, Haiyan; Han, Jing; Chen, Huanwen

2017-08-01

It is of sustainable interest to improve the sensitivity and selectivity of the ionization process, especially for direct analysis of complex samples without matrix separation. Herein, four ambient ionization methods including desorption atmospheric pressure chemical ionization (DAPCI), heat-assisted desorption atmospheric pressure chemical ionization (heat-assisted DAPCI), microwave plasma torch (MPT) and internal extractive electrospray ionization (iEESI) were employed for comparative analysis of the navel orange tissue samples by mass spectrometry. The volatile organic compounds (e.g. ethanol, vanillin, leaf alcohol and jasmine lactone) were successfully detected by non-heat-assisted DAPCI-MS, while semi-volatile organic compounds (e.g. 1-nonanol and ethyl nonanoate) together with low abundance of non-volatile organic compounds (e.g. sinensetin and nobiletin) were obtained by heat-assisted DAPCI-MS. Typical nonvolatile organic compounds [e.g. 5-(hydroxymethyl)furfural and glucosan] were sensitively detected with MPT-MS. Compounds of high polarity (e.g. amino acids, alkaloids and sugars) were easily profiled with iEESI-MS. Our data showed that more analytes could be detected when more energy was delivered for the desorption ionization purpose; however, heat-sensitive analytes would not be detected once the energy input exceeded the dissociation barriers of the analytes. For the later cases, soft ionization methods such as iEESI were recommended to sensitively profile the bioanalytes of high polarity. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Evaluation of MEGAN-CLM parameter sensitivity to predictions of isoprene emissions from an Amazonian rainforest

NASA Astrophysics Data System (ADS)

Holm, J. A.; Jardine, K.; Guenther, A. B.; Chambers, J. Q.; Tribuzy, E.

2014-09-01

Tropical trees are known to be large emitters of biogenic volatile organic compounds (BVOC), accounting for up to 75% of the global isoprene budget. Once in the atmosphere, these compounds influence multiple processes associated with air quality and climate. However, uncertainty in biogenic emissions is two-fold, (1) the environmental controls over isoprene emissions from tropical forests remain highly uncertain; and (2) our ability to accurately represent these environmental controls within models is lacking. This study evaluated the biophysical parameters that drive the global Model of Emissions of Gases and Aerosols from Nature (MEGAN) embedded in a biogeochemistry land surface model, the Community Land Model (CLM), with a focus on isoprene emissions from an Amazonian forest. Upon evaluating the sensitivity of 19 parameters in CLM that currently influence isoprene emissions by using a Monte Carlo analysis, up to 61% of the uncertainty in mean isoprene emissions was caused by the uncertainty in the parameters related to leaf temperature. The eight parameters associated with photosynthetic active radiation (PAR) contributed in total to only 15% of the uncertainty in mean isoprene emissions. Leaf temperature was strongly correlated with isoprene emission activity (R2 = 0.89). However, when compared to field measurements in the Central Amazon, CLM failed to capture the upper 10-14 °C of leaf temperatures throughout the year (i.e., failed to represent ~32 to 46 °C), and the spread observed in field measurements was not representative in CLM. This is an important parameter to accurately simulate due to the non-linear response of emissions to temperature. MEGAN-CLM 4.0 overestimated isoprene emissions by 60% for a Central Amazon forest (5.7 mg m-2 h-1 vs. 3.6 mg m-2 h-1), but due to reductions in leaf area index (LAI) by 28% in MEGAN-CLM 4.5 isoprene emissions were within 7% of observed data (3.8 mg m-2 h-1). When a slight adjustment to leaf temperature was made to match observations, isoprene emissions increased 24%, up to 4.8 mg m-2 h-1. Air temperatures are very likely to increase in tropical regions as a result of human induced climate change. Reducing the uncertainty of leaf temperature in BVOC algorithms, as well as improving the accuracy of replicating leaf temperature output in land surface models is warranted in order to improve estimations of tropical BVOC emissions.

Lotus Dust Mitigation Coating and Molecular Adsorber Coating

NASA Technical Reports Server (NTRS)

O'Connor, Kenneth M.; Abraham, Nithin S.

2015-01-01

NASA Goddard Space Flight Center has developed two unique coating formulations that will keep surfaces clean and sanitary and contain contaminants.The Lotus Dust Mitigation Coating, modeled after the self-cleaning, water-repellant lotus leaf, disallows buildup of dust, dirt, water, and more on surfaces. This coating, has been successfully tested on painted, aluminum, glass, silica, and some composite surfaces, could aid in keeping medical assets clean.The Molecular Adsorber Coating is a zeolite-based, sprayable molecular adsorber coating, designed to prevent outgassing in materials in vacuums. The coating works well to adsorb volatiles and contaminates in manufacturing and processing, such as in pharmaceutical production. The addition of a biocide would also aid in controlling bacteria levels.

Alpine Warming induced Nitrogen Export from Green Lakes Valley, Colorado Front Range, USA

NASA Astrophysics Data System (ADS)

Barnes, R. T.; Williams, M. W.; Parman, J.

2012-12-01

Alpine ecosystems are particularly susceptible to disturbance due to their short growing seasons, sparse vegetation and thin soils. Atmospheric nitrogen deposition and warming temperatures currently affect Green Lakes Valley (GLV) within the Colorado Front Range. Research conducted within the alpine links chronic nitrogen inputs to a suite of ecological impacts, resulting in increased nitrate export. According to NADP records at the site, the atmospheric flux of nitrogen has decreased by 0.56 kg ha-1 yr-1 since 2000, due to a decrease in precipitation. Concurrent with this decrease, alpine nitrate yields have continued to increase; by 32% relative to the previous decade (1990-1999). In order to determine the source(s) of the sustained nitrate increases we utilized long term datasets to construct a mass balance model for four stream segments (glacier to subalpine) for nitrogen and weathering product constituents. We also compared geochemical fingerprints of various solute sources (glacial meltwater, thawing permafrost, snow, and stream water) to alpine stream water to determine if sources had changed over time. Long term trends indicate that in addition to increases in nitrate; sulfate, calcium, and silica have also increased over the same period. The geochemical composition of thawing permafrost (as indicated by rock glacial meltwater) suggests it is the source of these weathering products. Mass balance results indicate the high ammonium loads within glacial meltwater are rapidly nitrified, contributing approximately 0.45 kg yr-1 to the NO3- flux within the upper reaches of the watershed. The sustained export of these solutes during dry, summer months is likely facilitated by thawing cryosphere providing hydraulic connectivity late into the growing season. In a neighboring catchment, lacking permafrost and glacial features, there were no long term weathering or nitrogen solute trends; providing further evidence that the changes in alpine chemistry in GLV are likely due to cryospheric thaw exposing soils to biological and geochemical processes. These findings suggest that efforts to reduce nitrogen deposition loads may not improve water quality, as thawing cryosphere associated with climate change may affect alpine nitrate concentrations as much, or more than atmospheric deposition trends.

Two-Stage Fungal Pre-Treatment for Improved Biogas Production from Sisal Leaf Decortication Residues

PubMed Central

Muthangya, Mutemi; Mshandete, Anthony Manoni; Kivaisi, Amelia Kajumulo

2009-01-01

Sisal leaf decortications residue (SLDR) is amongst the most abundant agro-industrial residues in Tanzania and is a good feedstock for biogas production. Pre-treatment of the residue prior to its anaerobic digestion (AD) was investigated using a two-stage pre-treatment approach with two fungal strains, CCHT-1 and Trichoderma reesei in succession in anaerobic batch bioreactors. AD of the pre-treated residue with CCTH-1 at 10% (wet weight inoculum/SLDR) inoculum concentration incubated for four days followed by incubation for eight days with 25% (wet weight inoculum/SLDR) of T. reesei gave a methane yield of 0.292 ± 0.04 m3 CH4/kg volatile solids (VS)added. On reversing the pre-treatment succession of the fungal inocula using the same parameters followed by AD, methane yield decreased by about 55%. Generally, an increment in the range of 30–101% in methane yield in comparison to the un-treated SLDR was obtained. The results confirmed the potential of CCHT-1 followed by Trichoderma reesei fungi pre-treatment prior to AD to achieve significant improvement in biogas production from SLDR. PMID:20087466

The effects of mating status and time since mating on female sex pheromone levels in the rice leaf bug, Trigonotylus caelestialium

NASA Astrophysics Data System (ADS)

Yamane, Takashi; Yasuda, Tetsuya

2014-02-01

Although mating status affects future mating opportunities, the biochemical changes that occur in response to mating are not well understood. This study investigated the effects of mating status on the quantities of sex pheromone components found in whole-body extracts and volatile emissions of females of the rice leaf bug, Trigonotylus caelestialium. When sampled at one of four time points within a 4-day postmating period, females that had copulated with a male had greater whole-body quantities of sex pheromone components than those of virgin females sampled at the same times. The quantities of sex pheromone components emitted by virgin females over a 24-h period were initially high but then steadily decreased, whereas 24-h emissions were persistently low among mated females when measured at three time points within the 4 days after mating. As a result, soon after mating, the mated females emitted less sex pheromones than virgin females, but there were no significant differences between mated and virgin females at the end of the experiment. Thus, postmating reduction in the rate of emission of sex pheromones could explain previously observed changes in female attractiveness to male T. caelestialium.

Coupling two mercury resistance genes in Eastern cottonwood enhances the processing of organomercury.

PubMed

Lyyra, Satu; Meagher, Richard B; Kim, Tehryung; Heaton, Andrew; Montello, Paul; Balish, Rebecca S; Merkle, Scott A

2007-03-01

Eastern cottonwood (Populus deltoides Bartr. ex Marsh.) trees were engineered to express merA (mercuric ion reductase) and merB (organomercury lyase) transgenes in order to be used for the phytoremediation of mercury-contaminated soils. Earlier studies with Arabidopsis thaliana and Nicotiana tabacum showed that this gene combination resulted in more efficient detoxification of organomercurial compounds than did merB alone, but neither species is optimal for long-term field applications. Leaf discs from in vitro-grown merA, nptII (neomycin phosphotransferase) transgenic cottonwood plantlets were inoculated with Agrobacterium tumefaciens strain C58 carrying the merB and hygromycin resistance (hptII) genes. Polymerase chain reaction of shoots regenerated from the leaf discs under selection indicated an overall transformation frequency of 20%. Western blotting of leaves showed that MerA and MerB proteins were produced. In vitro-grown merA/merB plants were highly resistant to phenylmercuric acetate, and detoxified organic mercury compounds two to three times more rapidly than did controls, as shown by mercury volatilization assay. This indicates that these cottonwood trees are reasonable candidates for the remediation of organomercury-contaminated sites.

Essential oil composition of sweet basil (Ocimum basilicum L.) in symbiotic relationship with Piriformospora indica and paclobutrazol application under salt stress.

PubMed

Keramati, Sara; Pirdashti, Hemmatollah; Babaeizad, Valliollah; Dehestani, Ali

2016-12-01

Essential oil content and oil composition of paclobutrazol treated sweet basil (Ocimum basilicum L.) plant inoculated with Piriformospora indica under salt stress were investigated by GC-MS. The results show a slight increase in essential oil content when basil plants subjected to moderate salinity stress (3 dS m -1 of NaCl). It decreased signifiicantly with increasing salinity level to 9 dS m -1 . The findings revealed that leaf area, above ground and leaf dry weights, essential oil content and yield were significantly affected by P. indica inoculation, however paclobutrazol application significantly influenced essential oil yield but not content. Fungal symbiosis as well as paclobutrazol application ameliorated the negative effects of salinity on dry matter and essential oil yield. The main constituents found in the volatile oil of O. basilicum in control treatment were Geranial (26.03%), Neral (24.88%) and Estragole (24.78%). The compounds concentrations showed some differences in P. indica and paclobutrazol treatments. The results demonstrate that micorrhiza-like fungi concomitantly increase essential oil production and biomass in sweet basil, a medicinal herb rich in commercially valuable essential oils.

Fate of the explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in soil and bioaccumulation in bush bean hydroponic plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harvey, S.D.; Fellows, R.J.; Cataldo, D.A.

Soils amended with [[sup 14]C]hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) were sampled over 60 d and subjected to exhaustive Soxhlet extraction followed by HPLC analysis. RDX was the only radiolabeled compound observed in soil extracts. Emission of volatile organics and [sup 14]CO[sub 2] from soil accounted for only 0.31 % of the amended radiolabel. Mass balance for RDX-amended soil was better than 84% throughout the two-month study. The analytical method developed for plants involved acid hydrolysis, solvent extraction, fractionation on Florisil adsorbent and separation by HPLC. The described methodology allowed for RDX recovery of 86 [+-] 3% from fortified bush bean leaf tissue. Furthermore » experiments were conducted with bush bean plants maintained on RDX-containing hydroponic solutions. Hydroponic plants did not emit detectable amounts of [sup 14]CO[sub 2] or radiolabeled volatile organics. Analysis of the plant tissue indicated bioaccumulation of RDX in the aerial tissues of hydroponic plants exposed for either 1 or 7 d. Metabolism of RDX to polar metabolites was observed in plants exposed for 7 d.« less

Evaluation of volatiles from Ampelopsis brevipedunculata var. heterophylla using GC-olfactometry, GC-MS and GC-pulsed flame photometric detector.

PubMed

Nakamura, Atsuhiko; Miyazawa, Mitsuo

2013-01-01

Ampelopsis brevipedunculata var. heterophylla is extensively cultivated in Asia, and the dried leaves and branches have a characteristic odor and have been used as a tea. To investigate the odorants contributing to the characteristic odor of A. brevipedunculata var. heterophylla, the aroma extraction dilution analysis method was performed through gas chromatography olfactometry. In addition, volatile sulfur compounds were evaluated using pulsed flame photometric detector. As a result, 86 compounds were identified in the oils of leaves and 78 in branches, accounting for 80.0% and 68.3%, respectively, of the compounds identified. The main compounds in the essential oil of leaves were palmitic acid (12.5%), phenylacetaldehyde (4.1%) and hexahydrofarnesyl acetone (3.9%). On the other hand, the essential oil of branches contained palmitic acid (12.7%), terpinen-4-ol (4.4%) and α-cadinol (3.7%). The total number of odor-active compounds identified in the leaf and branch oils was 39. The most odorous compounds of leaves and branches of A. brevipedunculata var. heterophylla were (E, Z)-2,6-nonadienal (melon, green odor), (E)-2-nonenal (grassy odor), phenylacetaldehyde (honey-like) and (E)-linalool oxide (woody odor).

Chemoreception of the Seagrass Posidonia Oceanica by Benthic Invertebrates is Altered by Seawater Acidification.

PubMed

Zupo, Valerio; Maibam, Chingoileima; Buia, Maria Cristina; Gambi, Maria Cristina; Patti, Francesco Paolo; Scipione, Maria Beatrice; Lorenti, Maurizio; Fink, Patrick

2015-08-01

Several plants and invertebrates interact and communicate by means of volatile organic compounds (VOCs). These compounds may play the role of infochemicals, being able to carry complex information to selected species, thus mediating inter- or intra-specific communications. Volatile organic compounds derived from the wounding of marine diatoms, for example, carry information for several benthic and planktonic invertebrates. Although the ecological importance of VOCs has been demonstrated, both in terrestrial plants and in marine microalgae, their role as infochemicals has not been demonstrated in seagrasses. In addition, benthic communities, even the most complex and resilient, as those associated to seagrass meadows, are affected by ocean acidification at various levels. Therefore, the acidification of oceans could produce interference in the way seagrass-associated invertebrates recognize and choose their specific environments. We simulated the wounding of Posidonia oceanica leaves collected at two sites (a control site at normal pH, and a naturally acidified site) off the Island of Ischia (Gulf of Naples, Italy). We extracted the VOCs and tested a set of 13 species of associated invertebrates for their specific chemotactic responses in order to determine if: a) seagrasses produce VOCs playing the role of infochemicals, and b) their effects can be altered by seawater pH. Our results indicate that several invertebrates recognize the odor of wounded P. oceanica leaves, especially those strictly associated to the leaf stratum of the seagrass. Their chemotactic reactions may be modulated by the seawater pH, thus impairing the chemical communications in seagrass-associated communities in acidified conditions. In fact, 54% of the tested species exhibited a changed behavioral response in acidified waters (pH 7.7). Furthermore, the differences observed in the abundance of invertebrates, in natural vs. acidified field conditions, are in agreement with these behavioral changes. Therefore, leaf-produced infochemicals may influence the structure of P. oceanica epifaunal communities, and their effects can be regulated by seawater acidification.

Canopy-scale flux measurements and bottom-up emission estimates of volatile organic compounds from a mixed oak and hornbeam forest in northern Italy

NASA Astrophysics Data System (ADS)

Acton, W. Joe F.; Schallhart, Simon; Langford, Ben; Valach, Amy; Rantala, Pekka; Fares, Silvano; Carriero, Giulia; Tillmann, Ralf; Tomlinson, Sam J.; Dragosits, Ulrike; Gianelle, Damiano; Hewitt, C. Nicholas; Nemitz, Eiko

2016-06-01

This paper reports the fluxes and mixing ratios of biogenically emitted volatile organic compounds (BVOCs) 4 m above a mixed oak and hornbeam forest in northern Italy. Fluxes of methanol, acetaldehyde, isoprene, methyl vinyl ketone + methacrolein, methyl ethyl ketone and monoterpenes were obtained using both a proton-transfer-reaction mass spectrometer (PTR-MS) and a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) together with the methods of virtual disjunct eddy covariance (using PTR-MS) and eddy covariance (using PTR-ToF-MS). Isoprene was the dominant emitted compound with a mean daytime flux of 1.9 mg m-2 h-1. Mixing ratios, recorded 4 m above the canopy, were dominated by methanol with a mean value of 6.2 ppbv over the 28-day measurement period. Comparison of isoprene fluxes calculated using the PTR-MS and PTR-ToF-MS showed very good agreement while comparison of the monoterpene fluxes suggested a slight over estimation of the flux by the PTR-MS. A basal isoprene emission rate for the forest of 1.7 mg m-2 h-1 was calculated using the Model of Emissions of Gases and Aerosols from Nature (MEGAN) isoprene emission algorithms (Guenther et al., 2006). A detailed tree-species distribution map for the site enabled the leaf-level emission of isoprene and monoterpenes recorded using gas-chromatography mass spectrometry (GC-MS) to be scaled up to produce a bottom-up canopy-scale flux. This was compared with the top-down canopy-scale flux obtained by measurements. For monoterpenes, the two estimates were closely correlated and this correlation improved when the plant-species composition in the individual flux footprint was taken into account. However, the bottom-up approach significantly underestimated the isoprene flux, compared with the top-down measurements, suggesting that the leaf-level measurements were not representative of actual emission rates.

Canopy-scale flux measurements and bottom-up emission estimates of volatile organic compounds from a mixed oak and hornbeam forest in northern Italy

NASA Astrophysics Data System (ADS)

Acton, W. J. F.; Schallhart, S.; Langford, B.; Valach, A.; Rantala, P.; Fares, S.; Carriero, G.; Tillmann, R.; Tomlinson, S. J.; Dragosits, U.; Gianelle, D.; Hewitt, C. N.; Nemitz, E.

2015-10-01

This paper reports the fluxes and mixing ratios of biogenically emitted volatile organic compounds (BVOCs) 4 m above a mixed oak and hornbeam forest in northern Italy. Fluxes of methanol, acetaldehyde, isoprene, methyl vinyl ketone + methacrolein, methyl ethyl ketone and monoterpenes were obtained using both a proton transfer reaction-mass spectrometer (PTR-MS) and a proton transfer reaction-time of flight-mass spectrometer (PTR-ToF-MS) together with the methods of virtual disjunct eddy covariance (PTR-MS) and eddy covariance (PTR-ToF-MS). Isoprene was the dominant emitted compound with a mean day-time flux of 1.9 mg m-2 h-1. Mixing ratios, recorded 4 m above the canopy, were dominated by methanol with a mean value of 6.2 ppbv over the 28 day measurement period. Comparison of isoprene fluxes calculated using the PTR-MS and PTR-ToF-MS showed very good agreement while comparison of the monoterpene fluxes suggested a slight over estimation of the flux by the PTR-MS. A basal isoprene emission rate for the forest of 1.7 mg m-2 h-1 was calculated using the MEGAN isoprene emissions algorithms (Guenther et al., 2006). A detailed tree species distribution map for the site enabled the leaf-level emissions of isoprene and monoterpenes recorded using GC-MS to be scaled up to produce a "bottom-up" canopy-scale flux. This was compared with the "top-down" canopy-scale flux obtained by measurements. For monoterpenes, the two estimates were closely correlated and this correlation improved when the plant species composition in the individual flux footprint was taken into account. However, the bottom-up approach significantly underestimated the isoprene flux, compared with the top-down measurements, suggesting that the leaf-level measurements were not representative of actual emission rates.

Monoterpene and herbivore-induced emissions from cabbage plants grown at elevated atmospheric CO 2 concentration

NASA Astrophysics Data System (ADS)

Vuorinen, Terhi; Reddy, G. V. P.; Nerg, Anne-Marja; Holopainen, Jarmo K.

The warming of the lower atmosphere due to elevating CO 2 concentration may increase volatile organic compound (VOC) emissions from plants. Also, direct effects of elevated CO 2 on plant secondary metabolism are expected to lead to increased VOC emissions due to allocation of excess carbon on secondary metabolites, of which many are volatile. We investigated how growing at doubled ambient CO 2 concentration affects emissions from cabbage plants ( Brassica oleracea subsp. capitata) damaged by either the leaf-chewing larvae of crucifer specialist diamondback moth ( Plutella xylostella L.) or generalist Egyptian cotton leafworm ( Spodoptera littoralis (Boisduval)). The emission from cabbage cv. Lennox grown in both CO 2 concentrations, consisted mainly of monoterpenes (sabinene, limonene, α-thujene, 1,8-cineole, β-pinene, myrcene, α-pinene and γ-terpinene). ( Z)-3-Hexenyl acetate, sesquiterpene ( E, E)- α-farnesene and homoterpene ( E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) were emitted mainly from herbivore-damaged plants. Plants grown at 720 μmol mol -1 of CO 2 had significantly lower total monoterpene emissions per shoot dry weight than plants grown at 360 μmol mol -1 of CO 2, while damage by both herbivores significantly increased the total monoterpene emissions compared to intact plants. ( Z)-3-Hexenyl acetate, ( E, E)- α-farnesene and DMNT emissions per shoot dry weight were not affected by the growth at elevated CO 2. The emission of DMNT was significantly enhanced from plants damaged by the specialist P. xylostella compared to the plants damaged by the generalist S. littoralis. The relative proportions of total monoterpenes and total herbivore-induced compounds of total VOCs did not change due to the growth at elevated CO 2, while insect damage increased significantly the proportion of induced compounds. The results suggest that VOC emissions that are induced by the leaf-chewing herbivores will not be influenced by elevated CO 2 concentration.

Jasmonate-Mediated Induced Volatiles in the American Cranberry, Vaccinium macrocarpon: From Gene Expression to Organismal Interactions

PubMed Central

Rodriguez-Saona, Cesar R.; Polashock, James; Malo, Edi A.

2013-01-01

Jasmonates, i.e., jasmonic acid (JA) and methyl jasmonate (MeJA), are signaling hormones that regulate a large number of defense responses in plants which in turn affect the plants’ interactions with herbivores and their natural enemies. Here, we investigated the effect of jasmonates on the emission of volatiles in the American cranberry, Vaccinium macrocarpon, at different levels of biological organization from gene expression to organismal interactions. At the molecular level, four genes (BCS, LLS, NER1, and TPS21) responded significantly to gypsy moth larval feeding, MeJA, and mechanical wounding, but to different degrees. The most dramatic changes in expression of BCS and TPS21 (genes in the sesquiterpenoid pathway) were when treated with MeJA. Gypsy moth-damaged and MeJA-treated plants also had significantly elevated expression of LLS and NER1 (genes in the monoterpene and homoterpene biosynthesis pathways, respectively). At the biochemical level, MeJA induced a complex blend of monoterpene and sesquiterpene compounds that differed from gypsy moth and mechanical damage, and followed a diurnal pattern of emission. At the organismal level, numbers of Sparganothis sulfureana moths were lower while numbers of parasitic wasps were higher on sticky traps near MeJA-treated cranberry plants than those near untreated plants. Out of 11 leaf volatiles tested, (Z)-3-hexenyl acetate, linalool, and linalool oxide elicited strong antennal (EAG) responses from S. sulfureana, whereas sesquiterpenes elicited weak EAG responses. In addition, mortality of S. sulfureana larvae increased by about 43% in JA treated cranberry plants as compared with untreated plants, indicating a relationship among adult preference, antennal sensitivity to plant odors, and offspring performance. This study highlights the role of the jasmonate-dependent defensive pathway in the emissions of herbivore-induced volatiles in cranberries and its importance in multi-trophic level interactions. PMID:23641249

Jasmonate-Mediated Induced Volatiles in the American Cranberry, Vaccinium macrocarpon: From Gene Expression to Organismal Interactions.

PubMed

Rodriguez-Saona, Cesar R; Polashock, James; Malo, Edi A

2013-01-01

Jasmonates, i.e., jasmonic acid (JA) and methyl jasmonate (MeJA), are signaling hormones that regulate a large number of defense responses in plants which in turn affect the plants' interactions with herbivores and their natural enemies. Here, we investigated the effect of jasmonates on the emission of volatiles in the American cranberry, Vaccinium macrocarpon, at different levels of biological organization from gene expression to organismal interactions. At the molecular level, four genes (BCS, LLS, NER1, and TPS21) responded significantly to gypsy moth larval feeding, MeJA, and mechanical wounding, but to different degrees. The most dramatic changes in expression of BCS and TPS21 (genes in the sesquiterpenoid pathway) were when treated with MeJA. Gypsy moth-damaged and MeJA-treated plants also had significantly elevated expression of LLS and NER1 (genes in the monoterpene and homoterpene biosynthesis pathways, respectively). At the biochemical level, MeJA induced a complex blend of monoterpene and sesquiterpene compounds that differed from gypsy moth and mechanical damage, and followed a diurnal pattern of emission. At the organismal level, numbers of Sparganothis sulfureana moths were lower while numbers of parasitic wasps were higher on sticky traps near MeJA-treated cranberry plants than those near untreated plants. Out of 11 leaf volatiles tested, (Z)-3-hexenyl acetate, linalool, and linalool oxide elicited strong antennal (EAG) responses from S. sulfureana, whereas sesquiterpenes elicited weak EAG responses. In addition, mortality of S. sulfureana larvae increased by about 43% in JA treated cranberry plants as compared with untreated plants, indicating a relationship among adult preference, antennal sensitivity to plant odors, and offspring performance. This study highlights the role of the jasmonate-dependent defensive pathway in the emissions of herbivore-induced volatiles in cranberries and its importance in multi-trophic level interactions.

Insect herbivore feeding and their excretion contribute to volatile organic compounds emission to the atmosphere

NASA Astrophysics Data System (ADS)

Zebelo, S.; Gnavi, G.; Bertea, C.; Bossi, S.; Andrea, O.; Cordero, C.; Rubiolo, P.; Bicchi, C.; Maffei, M.

2011-12-01

Secondary plant metabolites play an important role in insect plant interactions. The Lamiaceae family, especially Mentha species, accumulate secondary plant metabolites in their glandular trichomes, mainly mono and sesquiterpenes. Here we show that mint plants respond to herbivory by changing the quality and quantity of leaf secondary plant metabolite components. The volatiles from herbivore damaged, mechanical damage and healthy plant were collected by HS-SPME and analyzed by GC-MS. Plants with the same treatment were kept for genomic analysis. Total RNA was extracted from the above specified treatments. The terpenoid quantitative gene expressions (qPCR) were then assayed. Upon herbivory, M. aquatica synthesizes and emits (+)-menthofuran and the other major monoterpene (+)-pulegone emitted by healthy and mechanically damaged plants. Herbivory was found to up-regulate the expression of genes involved in terpenoid biosynthesis. The increased emission of (+)-menthofuran was correlated with the upregulation of (+)-menthofuran synthase. In addition we analysed the VOC composition of C. herbacea frass from insects feeding on Mentha aquatica. VOCs were sampled by HS-SPME and analyzed by GCxGC-qMS, and the results compared through quantitative comparative analysis of 2D chromatographic data. Most terpenoids from M. aquatica were completely catabolized by C. herbacea and were absent in the frass volatile fraction. On the other hand, the monoterpene 1,8-cineole was oxidized and frass yielded several new hydroxy-1,8-cineoles, among which 2α-OH-, 3α-OH-, 3β-OH- and 9-OH-1,8-cineole. The role of VOC emitted during herbivory and frass excretion on secondary organic aerosol formation is discussed.

Plant elicitor peptides are conserved signals regulating direct and indirect antiherbivore defense

PubMed Central

Huffaker, Alisa; Pearce, Gregory; Veyrat, Nathalie; Erb, Matthias; Turlings, Ted C. J.; Sartor, Ryan; Shen, Zhouxin; Briggs, Steven P.; Vaughan, Martha M.; Alborn, Hans T.; Teal, Peter E. A.; Schmelz, Eric A.

2013-01-01

Insect-induced defenses occur in nearly all plants and are regulated by conserved signaling pathways. As the first described plant peptide signal, systemin regulates antiherbivore defenses in the Solanaceae, but in other plant families, peptides with analogous activity have remained elusive. In the current study, we demonstrate that a member of the maize (Zea mays) plant elicitor peptide (Pep) family, ZmPep3, regulates responses against herbivores. Consistent with being a signal, expression of the ZmPROPEP3 precursor gene is rapidly induced by Spodoptera exigua oral secretions. At concentrations starting at 5 pmol per leaf, ZmPep3 stimulates production of jasmonic acid, ethylene, and increased expression of genes encoding proteins associated with herbivory defense. These include proteinase inhibitors and biosynthetic enzymes for production of volatile terpenes and benzoxazinoids. In accordance with gene expression data, plants treated with ZmPep3 emit volatiles similar to those from plants subjected to herbivory. ZmPep3-treated plants also exhibit induced accumulation of the benzoxazinoid phytoalexin 2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one glucoside. Direct and indirect defenses induced by ZmPep3 contribute to resistance against S. exigua through significant reduction of larval growth and attraction of Cotesia marginiventris parasitoids. ZmPep3 activity is specific to Poaceous species; however, peptides derived from PROPEP orthologs identified in Solanaceous and Fabaceous plants also induce herbivory-associated volatiles in their respective species. These studies demonstrate that Peps are conserved signals across diverse plant families regulating antiherbivore defenses and are likely to be the missing functional homologs of systemin outside of the Solanaceae. PMID:23509266

Ozone Differentially Affects Perception of Plant Volatiles in Western Honey Bees.

PubMed

Dötterl, Stefan; Vater, Marina; Rupp, Thomas; Held, Andreas

2016-06-01

Floral scents play a key role in mediating plant-pollinator interactions. Volatile organic compounds (VOCs) emitted by flowers are used by flower visitors as olfactory cues to locate flowers, both from a distance and at close range. More recently it has been demonstrated that reactive molecules such as ozone can modify or degrade VOCs, and this may impair the communication between plants and their pollinators. However, it is not known whether such reactive molecules also may affect the olfactory system of pollinators, and thus not only influence signal transmission but perception of the signal. In this study, we used electroantennographic measurements to determine the effect of increased levels of ozone on antennal responses in western honey bees (Apis mellifera L.). Linalool and 2-phenylethanol, both known to be involved in location of flowers by the bees, and (Z)-3-hexenyl acetate, a widespread green leaf volatile also detected by bees, were used. The results showed that ozone affected antennal responses to the different substances differently. Ozone decreased antennal responses to (Z)-3-hexenyl acetate, whereas responses to linalool and 2-phenylethanol were not influenced by ozone. Overall, the study does not provide evidence that pollination by honey bees is impaired by damage in the olfactory system of the bees caused by increased levels of ozone, at least when linalool and 2-phenylethanol are the attractive signals. However, the results also suggest that ozone can change the overall perception of an odor blend. This might have negative effects in pollination systems and other organismic interactions mediated by specific ratios of compounds.

Differential response in foliar chemistry of three ash species to emerald ash borer adult feeding.

PubMed

Chen, Yigen; Whitehill, Justin G A; Bonello, Pierluigi; Poland, Therese M

2011-01-01

The emerald ash borer (EAB; Agrilus planipennis Fairmaire; Coleoptera: Buprestidae), is an exotic wood-boring beetle that has been threatening North American ash (Fraxinus spp.) resources since its discovery in Michigan and Ontario in 2002. In this study, we investigated the phytochemical responses of the three most common North American ash species (black, green, and white ash) in northeastern USA to EAB adult feeding. Black ash was the least responsive to EAB adult feeding in terms of the induction of volatile compounds, and levels of only two (indole and benzyl cyanide) of the 11 compounds studied increased. In green ash, levels of two [(E)-β-ocimene and indole] of the 11 volatile compounds studied were elevated, while the levels of two green leaf volatiles [hexanal and (E)-2-hexenal] decreased. White ash showed the greatest response with an increase in levels of seven of the 11 compounds studied. Qualitative differences among ash species were detected. Among the phenolic compounds detected, ligustroside was the only one detected in all three species. Oleuropein aglycone and 2 unidentified compounds were found only in black ash; coumaroylquinic acid and feruloylquinic acid were detected only in green ash; and verbascoside hexoside was detected only in white ash. EAB adult feeding did not elicit or decrease concentrations of any selected individual phenolic compounds. However, although levels of total phenolics from black and green ash foliage were not affected by EAB adult feeding, they decreased significantly in white ash. EAB adult feeding elevated chymotrypsin inhibitors in black ash. The possible ecological implications of these findings are discussed.

Key volatile aroma compounds of three black velvet tamarind (Dialium) fruit species.

PubMed

Lasekan, Ola; See, Ng Siew

2015-02-01

Nineteen odour-active compounds were quantified in three black velvet tamarind fruit species. Calculation of the odour activity values (OAVs) of the odorants showed that differences in odour profiles of the tamarinds were mainly caused by linalool, limonene, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, nonanal, and (Z)-3-hexenal. On the basis of their high OAVs, cis-linalool oxide (furanoid), geranyl acetone, and cinnamyl acetate were identified as other potent odorants in the three tamarinds. Sensory studies revealed very distinct aroma profiles, which are characteristic of these types of fruits. While the Dialiumguineense elicited floral, flowery, caramel-like notes, the other two species were dominated by leaf-like, caramel, and green notes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Monoterpene and sesquiterpene emissions from Quercus coccifera exhibit interacting responses to light and temperature

NASA Astrophysics Data System (ADS)

Staudt, M.; Lhoutellier, L.

2011-09-01

Light and temperature are known to be the most important environmental factors controlling biogenic volatile organic compound (BVOC) emissions from plants, but little is known about their interdependencies especially for BVOCs other than isoprene. We studied light responses at different temperatures and temperature responses at different light levels of foliar BVOC emissions, photosynthesis and chlorophyll fluorescence on Quercus coccifera, an evergreen oak widespread in Mediterranean shrublands. More than 50 BVOCs were detected in the emissions from Q. coccifera leaves most of them being isoprenoids plus a few green leaf volatiles (GLVs). Under standard conditions non-oxygenated monoterpenes (MT-hc) accounted for about 90% of the total BVOC release (mean ± SD: 738 ± 378 ng m-2 projected leaf area s-1 or 13.1 ± 6.9 μg g-1 leaf dry weight h-1) and oxygenated monoterpenes (MT-ox) and sesquiterpenes (SQTs) accounted for the rest in about equal proportions. Except GLVs, emissions of all BVOCs responded positively to light and temperature. The light responses of MT and SQT emissions resembled that of CO2-assimilation and were little influenced by the assay temperature: at high assay temperature, MT-hc emissions saturated at lower light levels than at standard assay temperature and tended even to decrease in the highest light range. The emission responses to temperature showed mostly Arrhenius-type response curves, whose shapes in the high temperature range were clearly affected by the assay light level and were markedly different between isoprenoid classes: at non-saturating light, all isoprenoids showed a similar temperature optimum (~43 °C), but, at higher temperatures, MT-hc emissions decreased faster than MT-ox and SQT emissions. At saturating light, MT-hc emissions peaked around 37 °C and rapidly dropped at higher temperatures, whereas MT-ox and SQT emissions strongly increased between 40 and 50 °C accompanied by a burst of GLVs. In all experiments, decreases of MT-hc emissions under high temperatures were correlated with decreases in CO2-assimilation and/or photosynthetic electron transport. We conclude that light and temperature can have interactive short-term effects on the quantity and quality of BVOC emissions from Q. coccifera through substrate limitations of MT biosynthesis occurring at temperatures supraoptimal for photosynthetic processes that are exacerbated by oxidative stress and membrane damages. Such interactive effects are likely to occur frequently during hot and dry summers and simulations made in this work showed that they may have important consequences for emission predictions.

Monoterpene and sesquiterpene emissions from Quercus coccifera exhibit interacting responses to light and temperature

NASA Astrophysics Data System (ADS)

Staudt, M.; Lhoutellier, L.

2011-06-01

Light and temperature are known to be the most important environmental factors controlling biogenic volatile organic compound (BVOC) emissions from plants, but little is known about their interdependencies especially for BVOCs other than isoprene. We studied light responses at different temperatures and temperature responses at different light levels of foliar BVOC emissions, photosynthesis and chlorophyll fluorescence on Quercus coccifera, an evergreen oak widespread in Mediterranean shrublands. More than 50 BVOCs were detected in the emissions from Q. coccifera leaves most of them being isoprenoids plus a few green leaf volatiles (GLVs). Under standard conditions non-oxygenated monoterpenes (MT-hc) accounted for about 90 % of the total BVOC release (mean ± SD: 738 ± 378 ng m-2 projected leaf area s-1 or 13.1 ± 6.9 μg g-1 leaf dry weight h-1) and oxygenated monoterpenes (MT-ox) and sesquiterpenes (SQTs) accounted for the rest in about equal proportions. Except GLVs, emissions of all BVOCs responded positively to light and temperature. The light responses of MT and SQT emissions resembled that of CO2-assimilation and were little influenced by the assay temperature: at high assay temperature, MT-hc emissions saturated at lower light levels than at standard assay temperature and tended even to decrease in the highest light range. The emission responses to temperature showed mostly Arrhenius-type response curves, whose shapes in the high temperature range were clearly affected by the assay light level and were markedly different between isoprenoid classes: at non-saturating light, all isoprenoids showed a similar temperature optimum (~43 °C), but, at higher temperatures, MT-hc emissions decreased faster than MT-ox and SQT emissions. At saturating light, MT-hc emissions peaked already around 37 °C and rapidly dropped at higher temperatures, whereas MT-ox and SQT emissions strongly increased between 40 and 50 °C accompanied by a burst of GLVs. In all experiments, decreases of MT-hc emissions under high temperatures were correlated with decreases in CO2-assimilation and/or photosynthetic electron transport. We conclude that light and temperature can have interactive short-term effects on the quantity and quality of BVOC emissions from Q. coccifera through substrate limitations of MT biosynthesis occurring at temperatures supraoptimal for photosynthetic processes that are exacerbated by oxidative stress and membrane damages. Such interactive effects are likely to occur frequently during hot and dry summers and simulations made in this work showed that they may have important consequences for emission predictions.

Emissions of biogenic volatile organic compounds from litter are coupled with changes in the microbial community composition

NASA Astrophysics Data System (ADS)

Hagel Svendsen, Sarah; Schostag, Morten; Voriskova, Jana; Kramshøj, Magnus; Priemé, Anders; Suhr Jacobsen, Carsten; Rinnan, Riikka

2017-04-01

Emissions of biogenic volatile organic compounds (BVOCs) from natural ecosystems have significant impact on atmospheric chemistry and belowground chemical processes. Most attention has been given to emissions from plants. However, several studies have found that soil, and especially the decomposing leaf and needle litter, emits substantial amounts of BVOCs. The contribution of litter to ecosystem BVOC emissions may be increasingly significant in the Arctic, where the living plant biomass is low, and the amount of litter increasing due to the expansion of deciduous vegetation in response to climate change. It is known that the types and amounts of BVOCs emitted from the soil are highly dependent on the microbial community composition and the type of substrate. In this study we measured emissions of BVOCs from the leaf litter of common arctic plant species at different temperatures. The BVOC measurements were coupled with an analysis of the relative abundance of dominating bacterial species (determined as operational taxonomic units, OTUs). Leaf litter from evergreen Cassiope tetragona and two species of deciduous Salix were collected from two arctic locations; one in the High Arctic and one in the Low Arctic. The litter was incubated in dark at 5 ?C. Over an eight week period the temperature was increased 7 ?C every two weeks, giving temperature incubations at 5 ?C, 12 ?C, 19 ?C and 26 ?C. Emissions of BVOCs from the litter were sampled in adsorbent cartridges weekly and analyzed using gas chromatography-mass spectrometry. The relative abundance of bacteria was determined at the end of the incubation at each temperature using DNA sequencing. Results showed that emissions of BVOCs belonging to different chemical functional groups responded differently to increasing temperatures and were highly dependent on the type of substrate. For instance, terpenoid emissions from the Cassiope litter increased with increasing temperature, whereas the emissions from the Salix litter decreased. Likewise, the relative abundance of bacteria depended on temperature and the type of substrate. Especially the actinobacteria showed strong increasing trends with increasing temperature in the Salix litter. Acidobacteria had much higher relative abundance in the Cassiope litter than in the Salix litter. Multivariate analyses were used to assess potential links between the BVOC and bacterial abundance datasets. Similar patterns in the BVOC emissions and bacterial community composition at different temperatures and for different substrates suggest that the differences in BVOC emissions, at least to some extent, are driven by changes in the microbial community composition.

Estimation of biogenic volatile organic compound (BVOC) emissions from the terrestrial ecosystem in China using real-time remote sensing data

NASA Astrophysics Data System (ADS)

Li, M.; Huang, X.; Li, J.; Song, Y.

2012-04-01

Because of the high emission intensity and reactivity, biogenic volatile organic compounds (BVOCs) play a significant role in the terrestrial ecosystems, human health, secondary pollution, global climate change and the global carbon cycle. Past estimations of BVOC emissions in China were based on outdated algorithms and limited meteorological data, and there have been significant inconsistences between the land surface parameters of dynamic models and those of BVOC estimation models, leading to large inaccuracies in the estimated results. To refine BVOC emission estimations for China and to further explore the role of BVOCs in atmospheric chemical processes, we used the latest algorithms of MEGAN (Model of Emissions of Gases and Aerosols from Nature) with MM5 (the Fifth-Generation Mesoscale Model) providing highly resolved meteorological data, to estimate the biogenic emissions of isoprene (C5H8) and seven monoterpene species (C10H16) in 2006. Real-time MODIS (Moderate Resolution Imaging Spectroradiometer) data were introduced to update the land surface parameters and improve the simulation performance of MM5, and to modify the influence of leaf area index (LAI) and leaf age deviation from standard conditions. In this study, the annual BVOC emissions for the whole country totaled 12.97 Tg C, a relevant value much lower than that given in global estimations but higher than the past estimations in China. Therein, the most important individual contributor was isoprene (9.36 Tg C), followed by α-pinene (1.24 Tg C yr-1) and β-pinene (0.84 Tg C yr-1). Due to the considerable regional disparity in plant distributions and meteorological conditions across China, BVOC emissions presented significant spatial-temporal variations. Spatially, isoprene emission was concentrated in South China, which is covered by large areas of broadleaf forests and shrubs. On the other hand, Southeast China was the top-ranking contributor of monoterpenes, in which the dominant vegetation genera consist of evergreen coniferous forests (mainly Pinus massoniana). Temporally, BVOC emissions primarily occurred in July and August during periods of high temperatures, high solar radiation and dense plant cover, with daily emissions peaking at about 13:00~14:00 hours (Beijing Time, BJT) and reaching their lowest values at night. Additionally, emissions of volatile organic compounds (VOCs) of biogenic origin (14.7 Tg yr-1) were approximately one-third less than anthropogenic emissions (23.2 Tg yr-1) and showed distinct spatial distributions. We present a reasonable estimation of BVOC emissions, which provides important information for further exploration of the role of BVOCs in atmospheric processes.

Volatile organic compound emissions from arctic vegetation highly responsive to experimental warming

NASA Astrophysics Data System (ADS)

Rinnan, Riikka; Kramshøj, Magnus; Lindwall, Frida; Schollert, Michelle; Svendsen, Sarah H.; Valolahti, Hanna

2017-04-01

Arctic areas are experiencing amplified climate warming that proceeds twice as fast as the global temperature increase. The increasing temperature is already causing evident alterations, e.g. changes in the vegetation cover as well as thawing of permafrost. Climate warming and the concomitant biotic and abiotic changes are likely to have strong direct and indirect effects on emission of volatile organic compounds (VOCs) from arctic vegetation. We used long-term field manipulation experiments in the Subarctic, Low Arctic and High Arctic to assess effects of climate change on VOC emissions from vegetation communities. In these experiments, we applied passive warming with open-top chambers alone and in combination with other experimental treatments in well-replicated experimental designs. Volatile emissions were sampled in situ by drawing air from plant enclosures and custom-built chambers into adsorbent cartridges, which were analyzed by thermal desorption and gas chromatography-mass spectrometry in laboratory. Emission increases by a factor of 2-5 were observed under experimental warming by only a few degrees, and the strong response seems universal for dry, mesic and wet ecosystems. In some cases, these vegetation community level responses were partly due to warming-induced increases in the VOC-emitting plant biomass, changes in species composition and the following increase in the amount of leaf litter (Valolahti et al. 2015). In other cases, the responses appeared before any vegetation changes took place (Lindwall et al. 2016) or even despite a decrease in plant biomass (Kramshøj et al. 2016). VOC emissions from arctic ecosystems seem more responsive to experimental warming than other ecosystem processes. We can thus expect large increases in future VOC emissions from this area due to the direct effects of temperature increase, and due to increasing plant biomass and a longer growing season. References Kramshøj M., Vedel-Petersen I., Schollert M., Rinnan Å., Nymand J., Ro-Poulsen H., Rinnan R. (2016) Large increases in arctic biogenic volatile emissions are a direct effect of warming. Nature Geoscience 9: 349-352. Lindwall F., Schollert M., Michelsen A., Blok D., Rinnan R. (2016) Fourfold higher tundra volatile emissions due to arctic summer warming. Journal of Geophysical Research: Biogeosciences 121: 895-902, doi: 10.1002/2015JG003295. Valolahti H., Kivimäenpää M., Faubert P., Michelsen A., Rinnan R. (2015) Climate change-induced vegetation change as a driver of increased subarctic biogenic volatile organic compound emissions. Global Change Biology 21: 3478-3488.

Regulation of Black Pepper Inflorescence Quantity by Shading at Different Growth Stages.

PubMed

Zu, Chao; Wu, Guiping; Li, Zhigang; Yang, Jianfeng; Wang, Can; Yu, Huan; Wu, Huasong

2016-07-01

Black pepper is a perennial plant that can bloom throughout the year. It is generally expected that pepper inflorescence quantity could be minimized at the nonfull-bloom stage. The objective of this study was to find an appropriate shading measure that could inhibit blooming at other growing stages except the full-bloom stage and did not cause any reduction in pepper yield and quality. In this study, pepper trees were shaded up to 15%, 30%, 60% and 75%, respectively, and the inflorescence quantity, photosynthetic characteristics, pepper yield and quality traits were investigated at every growing stage. The results showed that the effect of shading on pepper yield decreased as time progressed. Shading treatment did not alter the composition of piperine and volatile oil, but reduced the moisture content. Based on the correlation between photosynthetic parameter and inflorescence number, the appropriate shading intensities for regulating inflorescence quantity at different phenological stages were determined. Moreover, it was found that the regulation of inflorescence quantity could be achieved by controlling leaf temperature during recovery to filling period. This research outcome also will give us some guidelines to develop other management strategies that control leaf temperature and regulate inflorescence quantity to consequently improve pepper yield. © 2016 The American Society of Photobiology.

Development of feeding systems and strategies of supplementation to enhance rumen fermentation and ruminant production in the tropics

PubMed Central

2013-01-01

The availability of local feed resources in various seasons can contribute as essential sources of carbohydrate and protein which significantly impact rumen fermentation and the subsequent productivity of the ruminant. Recent developments, based on enriching protein in cassava chips, have yielded yeast fermented cassava chip protein (YEFECAP) providing up to 47.5% crude protein (CP), which can be used to replace soybean meal. The use of fodder trees has been developed through the process of pelleting; Leucaena leucocephala leaf pellets (LLP), mulberry leaf pellets (MUP) and mangosteen peel and/or garlic pellets, can be used as good sources of protein to supplement ruminant feeding. Apart from producing volatile fatty acids and microbial proteins, greenhouse gases such as methane are also produced in the rumen. Several methods have been used to reduce rumen methane. However, among many approaches, nutritional manipulation using feed formulation and feeding management, especially the use of plant extracts or plants containing secondary compounds (condensed tannins and saponins) and plant oils, has been reported. This approach could help todecrease rumen protozoa and methanogens and thus mitigate the production of methane. At present, more research concerning this burning issue - the role of livestock in global warming - warrants undertaking further research with regard to economic viability and practical feasibility. PMID:23981662

Direct observation of the photodegradation of anthracene and pyrene adsorbed onto mangrove leaves.

PubMed

Wang, Ping; Wu, Tun-Hua; Zhang, Yong

2014-01-01

An established synchronous fluorimetry method was used for in situ investigation of the photodegradation of pyrene (PYR) and anthracene (ANT) adsorbed onto fresh leaves of the seedlings of two mangrove species, Aegiceras corniculatum (L.) Blanco (Ac) and Kandelia obovata (Ko) in multicomponent mixtures (mixture of the ANT and PYR). Experimental results indicated that photodegradation was the main transformation pathway for both ANT and PYR in multicomponent mixtures. The amount of the PAHs volatilizing from the leaf surfaces and entering the inner leaf tissues was negligible. Over a certain period of irradiation time, the photodegradation of both PYR and ANT adsorbed onto the leaves of Ac and Ko followed first-order kinetics, with faster rates being observed on Ac leaves. In addition, the photodegradation rate of PYR on the leaves of the mangrove species in multicomponent mixtures was much slower than that of adsorbed ANT. Compared with the PAHs adsorbed as single component, the photodegradation rate of ANT adsorbed in multicomponent mixtures was slower, while that of PYR was faster. Moreover, the photodegradation of PYR and ANT dissolved in water in multicomponent mixtures was investigated for comparison. The photodegradation rate on leaves was much slower than in water. Therefore, the physical-chemical properties of the substrate may strongly influence the photodegradation rate of adsorbed PAHs.

Volatilisation of pesticides under field conditions: inverse modelling and pesticide fate models.

PubMed

Houbraken, Michael; van den Berg, Frederik; Butler Ellis, Clare M; Dekeyser, Donald; Nuyttens, David; De Schampheleire, Mieke; Spanoghe, Pieter

2016-07-01

A substantial fraction of the applied crop protection products on crops is lost to the atmosphere. Models describing the prediction of volatility and potential fate of these substances in the environment have become an important tool in the pesticide authorisation procedure at the EU level. The main topic of this research is to assess the rate and extent of volatilisation of ten pesticides after application on field crops. For eight of the ten pesticides, the volatilisation rates modelled with PEARL (Pesticide Emission Assessment at Regional and Local scales) corresponded well to the calculated rates modelled with ADMS (Atmospheric Dispersion Modelling System). For the other pesticides, large differences were found between the models. Formulation might affect the volatilisation potential of pesticides. Increased leaf wetness increased the volatilisation of propyzamide and trifloxystrobin at the end of the field trial. The reliability of pesticide input parameters, in particular the vapour pressure, is discussed. Volatilisation of propyzamide, pyrimethanil, chlorothalonil, diflufenican, tolylfluanid, cyprodinil and E- and Z-dimethomorph from crops under realistic environmental conditions can be modelled with the PEARL model, as corroborated against field observations. Suggested improvements to the volatilisation component in PEARL should include formulation attributes and leaf wetness at the time of pesticide application. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Grapevine Plasticity in Response to an Altered Microclimate: Sauvignon Blanc Modulates Specific Metabolites in Response to Increased Berry Exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, Philip R.; Eyeghe-Bickong, Hans A.; du Plessis, Kari

In this paper, the metabolic and physiological impacts of an altered microclimate on quality-associated primary and secondary metabolites in grape (Vitis vinifera) ‘Sauvignon Blanc’ berries was determined in a high-altitude vineyard. The leaf and lateral shoot removal in the bunch zones altered the microclimate by increasing the exposure of the berries. The physical parameters (berry diameter and weight), primary metabolites (sugars and organic acids), as well as bunch temperature and leaf water potential were predominantly not affected by the treatment. The increased exposure led to higher levels of specific carotenoids and volatile terpenoids in the exposed berries, with earlier berrymore » stages reacting distinctly from the later developmental stages. Plastic/nonplastic metabolite responses could be further classified to identify metabolites that were developmentally controlled and/or responded to the treatment in a predictable fashion (assessed over two consecutive vintages). The study demonstrates that grapevine berries exhibit a degree of plasticity within their secondary metabolites and respond physiologically to the increased exposure by increasing metabolites with potential antioxidant activity. Finally, taken together, the data provide evidence that the underlying physiological responses relate to the maintenance of stress pathways by modulating antioxidant molecules in the berries.« less

Laurel leaf extracts for honeybee pest and disease management: antimicrobial, microsporicidal, and acaricidal activity.

PubMed

Damiani, Natalia; Fernández, Natalia J; Porrini, Martín P; Gende, Liesel B; Álvarez, Estefanía; Buffa, Franco; Brasesco, Constanza; Maggi, Matías D; Marcangeli, Jorge A; Eguaras, Martín J

2014-02-01

A diverse set of parasites and pathogens affects productivity and survival of Apis mellifera honeybees. In beekeeping, traditional control by antibiotics and molecules of synthesis has caused problems with contamination and resistant pathogens. In this research, different Laurus nobilis extracts are tested against the main honeybee pests through an integrated point of view. In vivo effects on bee survival are also evaluated. The ethanol extract showed minimal inhibitory concentration (MIC) values of 208 to 416 μg/mL, having the best antimicrobial effect on Paenibacillus larvae among all substances tested. Similarly, this leaf extract showed a significant antiparasitic activity on Varroa destructor, killing 50 % of mites 24 h after a 30-s exposure, and on Nosema ceranae, inhibiting the spore development in the midgut of adult bees ingesting 1 × 10(4) μg/mL of extract solution. Both ethanol extract and volatile extracts (essential oil, hydrolate, and its main component) did not cause lethal effects on adult honeybees. Thus, the absence of topical and oral toxicity of the ethanol extract on bees and the strong antimicrobial, microsporicidal, and miticidal effects registered in this study place this laurel extract as a promising integrated treatment of bee diseases and stimulates the search for other bioactive phytochemicals from plants.

Grapevine Plasticity in Response to an Altered Microclimate: Sauvignon Blanc Modulates Specific Metabolites in Response to Increased Berry Exposure

DOE PAGES

Young, Philip R.; Eyeghe-Bickong, Hans A.; du Plessis, Kari; ...

2015-12-01

In this paper, the metabolic and physiological impacts of an altered microclimate on quality-associated primary and secondary metabolites in grape (Vitis vinifera) ‘Sauvignon Blanc’ berries was determined in a high-altitude vineyard. The leaf and lateral shoot removal in the bunch zones altered the microclimate by increasing the exposure of the berries. The physical parameters (berry diameter and weight), primary metabolites (sugars and organic acids), as well as bunch temperature and leaf water potential were predominantly not affected by the treatment. The increased exposure led to higher levels of specific carotenoids and volatile terpenoids in the exposed berries, with earlier berrymore » stages reacting distinctly from the later developmental stages. Plastic/nonplastic metabolite responses could be further classified to identify metabolites that were developmentally controlled and/or responded to the treatment in a predictable fashion (assessed over two consecutive vintages). The study demonstrates that grapevine berries exhibit a degree of plasticity within their secondary metabolites and respond physiologically to the increased exposure by increasing metabolites with potential antioxidant activity. Finally, taken together, the data provide evidence that the underlying physiological responses relate to the maintenance of stress pathways by modulating antioxidant molecules in the berries.« less

Grapevine Plasticity in Response to an Altered Microclimate: Sauvignon Blanc Modulates Specific Metabolites in Response to Increased Berry Exposure.

PubMed

Young, Philip R; Eyeghe-Bickong, Hans A; du Plessis, Kari; Alexandersson, Erik; Jacobson, Dan A; Coetzee, Zelmari; Deloire, Alain; Vivier, Melané A

2016-03-01

In this study, the metabolic and physiological impacts of an altered microclimate on quality-associated primary and secondary metabolites in grape (Vitis vinifera) 'Sauvignon Blanc' berries was determined in a high-altitude vineyard. The leaf and lateral shoot removal in the bunch zones altered the microclimate by increasing the exposure of the berries. The physical parameters (berry diameter and weight), primary metabolites (sugars and organic acids), as well as bunch temperature and leaf water potential were predominantly not affected by the treatment. The increased exposure led to higher levels of specific carotenoids and volatile terpenoids in the exposed berries, with earlier berry stages reacting distinctly from the later developmental stages. Plastic/nonplastic metabolite responses could be further classified to identify metabolites that were developmentally controlled and/or responded to the treatment in a predictable fashion (assessed over two consecutive vintages). The study demonstrates that grapevine berries exhibit a degree of plasticity within their secondary metabolites and respond physiologically to the increased exposure by increasing metabolites with potential antioxidant activity. Taken together, the data provide evidence that the underlying physiological responses relate to the maintenance of stress pathways by modulating antioxidant molecules in the berries. © 2016 American Society of Plant Biologists. All Rights Reserved.

Grapevine Plasticity in Response to an Altered Microclimate: Sauvignon Blanc Modulates Specific Metabolites in Response to Increased Berry Exposure1

PubMed Central

du Plessis, Kari; Jacobson, Dan A.

2016-01-01

In this study, the metabolic and physiological impacts of an altered microclimate on quality-associated primary and secondary metabolites in grape (Vitis vinifera) ‘Sauvignon Blanc’ berries was determined in a high-altitude vineyard. The leaf and lateral shoot removal in the bunch zones altered the microclimate by increasing the exposure of the berries. The physical parameters (berry diameter and weight), primary metabolites (sugars and organic acids), as well as bunch temperature and leaf water potential were predominantly not affected by the treatment. The increased exposure led to higher levels of specific carotenoids and volatile terpenoids in the exposed berries, with earlier berry stages reacting distinctly from the later developmental stages. Plastic/nonplastic metabolite responses could be further classified to identify metabolites that were developmentally controlled and/or responded to the treatment in a predictable fashion (assessed over two consecutive vintages). The study demonstrates that grapevine berries exhibit a degree of plasticity within their secondary metabolites and respond physiologically to the increased exposure by increasing metabolites with potential antioxidant activity. Taken together, the data provide evidence that the underlying physiological responses relate to the maintenance of stress pathways by modulating antioxidant molecules in the berries. PMID:26628747

Shelf-life extension of refrigerated sea bass slices wrapped with fish protein isolate/fish skin gelatin-ZnO nanocomposite film incorporated with basil leaf essential oil.

PubMed

Arfat, Yasir Ali; Benjakul, Soottawat; Vongkamjan, Kitiya; Sumpavapol, Punnanee; Yarnpakdee, Suthasinee

2015-10-01

Microbiological, chemical and sensory changes of sea bass slices wrapped with fish protein isolate (FPI)/fish skin gelatin (FSG) films incorporated with 3 % ZnO nanoparticles (ZnONP) (w/w, based on protein content) and 100 % basil leaf essential oil (BEO) (w/w, based on protein content) during storage of 12 days at 4 °C were investigated. Sea bass slices wrapped with FPI/FSG-ZnONP-BEO film had the lowest growth of psychrophilic bacteria, lactic acid bacteria and spoilage microorganisms including Pseudomonas , H2S-producing bacteria and Enterobacteriaceae throughout storage of 12 days in comparison with those wrapped with FPI/FSG-BEO, FPI/FSG-ZnONP, FPI/FSG film, polypropylene film (PP film) and the control (without wrapping), respectively (P < 0.05). Lowered increases in pH, total volatile base, peroxide value and TBARS value were found in FPI/FSG-ZnO-BEO film wrapped samples, compared with others (P < 0.05). Sensory evaluation revealed that shelf-life of sea bass slices was longest for samples wrapped with FPI/FSG-ZnONP-BEO film (12 days), as compared to the control (6 days) (P < 0.05).

NaJAZh Regulates a Subset of Defense Responses against Herbivores and Spontaneous Leaf Necrosis in Nicotiana attenuata Plants[C][W][OA

PubMed Central

Oh, Youngjoo; Baldwin, Ian T.; Gális, Ivan

2012-01-01

The JASMONATE ZIM DOMAIN (JAZ) proteins function as negative regulators of jasmonic acid signaling in plants. We cloned 12 JAZ genes from native tobacco (Nicotiana attenuata), including nine novel JAZs in tobacco, and examined their expression in plants that had leaves elicited by wounding or simulated herbivory. Most JAZ genes showed strong expression in the elicited leaves, but NaJAZg was mainly expressed in roots. Another novel herbivory-elicited gene, NaJAZh, was analyzed in detail. RNA interference suppression of this gene in inverted-repeat (ir)JAZh plants deregulated a specific branch of jasmonic acid-dependent direct and indirect defenses: irJAZh plants showed greater trypsin protease inhibitor activity, 17-hydroxygeranyllinalool diterpene glycosides accumulation, and emission of volatile organic compounds from leaves. Silencing of NaJAZh also revealed a novel cross talk in JAZ-regulated secondary metabolism, as irJAZh plants had significantly reduced nicotine levels. In addition, irJAZh spontaneously developed leaf necrosis during the transition to flowering. Because the lesions closely correlated with the elevated expression of programmed cell death genes and the accumulations of salicylic acid and hydrogen peroxide in the leaves, we propose a novel role of the NaJAZh protein as a repressor of necrosis and/or programmed cell death during plant development. PMID:22496510

Direct Observation of the Photodegradation of Anthracene and Pyrene Adsorbed onto Mangrove Leaves

PubMed Central

Wang, Ping; Wu, Tun-Hua; Zhang, Yong

2014-01-01

An established synchronous fluorimetry method was used for in situ investigation of the photodegradation of pyrene (PYR) and anthracene (ANT) adsorbed onto fresh leaves of the seedlings of two mangrove species, Aegiceras corniculatum (L.) Blanco (Ac) and Kandelia obovata (Ko) in multicomponent mixtures (mixture of the ANT and PYR). Experimental results indicated that photodegradation was the main transformation pathway for both ANT and PYR in multicomponent mixtures. The amount of the PAHs volatilizing from the leaf surfaces and entering the inner leaf tissues was negligible. Over a certain period of irradiation time, the photodegradation of both PYR and ANT adsorbed onto the leaves of Ac and Ko followed first-order kinetics, with faster rates being observed on Ac leaves. In addition, the photodegradation rate of PYR on the leaves of the mangrove species in multicomponent mixtures was much slower than that of adsorbed ANT. Compared with the PAHs adsorbed as single component, the photodegradation rate of ANT adsorbed in multicomponent mixtures was slower, while that of PYR was faster. Moreover, the photodegradation of PYR and ANT dissolved in water in multicomponent mixtures was investigated for comparison. The photodegradation rate on leaves was much slower than in water. Therefore, the physical-chemical properties of the substrate may strongly influence the photodegradation rate of adsorbed PAHs. PMID:25144741

Elevation of night-time temperature increases terpenoid emissions from Betula pendula and Populus tremula

PubMed Central

Ibrahim, Mohamed A.; Mäenpää, Maarit; Hassinen, Viivi; Kontunen-Soppela, Sari; Malec, Lukáš; Rousi, Matti; Pietikäinen, Liisa; Tervahauta, Arja; Kärenlampi, Sirpa; Holopainen, Jarmo K.; Oksanen, Elina J.

2010-01-01

Volatile organic compounds (VOCs) are expected to have an important role in plant adaptation to high temperatures. The impacts of increasing night-time temperature on daytime terpenoid emissions and related gene expression in silver birch (Betula pendula) and European aspen (Populus tremula) clones were studied. The plants were grown under five different night-time temperatures (6, 10, 14, 18, and 22 °C) while daytime temperature was kept at a constant 22 °C. VOC emissions were collected during the daytime and analysed by gas chromatography–mass spectrometry (GC-MS). In birch, emissions per leaf area of the C11 homoterpene 4,8-dimethy1-nona-1,3,7-triene (DMNT) and several sesquiterpenes were consistently increased with increasing night-time temperature. Total sesquiterpene (SQT) emissions showed an increase at higher temperatures. In aspen, emissions of DMNT and β-ocimene increased from 6 °C to 14 °C, while several other monoterpenes and the SQTs (Z,E)-α-farnesene and (E,E)-α-farnesene increased up to 18 °C. Total monoterpene and sesquiterpene emission peaked at 18 °C, whereas isoprene emissions decreased at 22 °C. Leaf area increased across the temperature range of 6–22 °C by 32% in birch and by 59% in aspen. Specific leaf area (SLA) was also increased in both species. The genetic regulation of VOC emissions seems to be very complex, as indicated by several inverse relationships between emission profiles and expression of several regulatory genes (DXR, DXS, and IPP). The study indicates that increasing night temperature may strongly affect the quantity and quality of daytime VOC emissions of northern deciduous trees. PMID:20181662

Jasmonates induce both defense responses and communication in monocotyledonous and dicotyledonous plants.

PubMed

Okada, Kazunori; Abe, Hiroshi; Arimura, Gen-ichiro

2015-01-01

Jasmonic acid (JA) and its derivatives (jasmonates, JAs) are phytohormones with essential roles in plant defense against pathogenesis and herbivorous arthropods. Both the up- and down-regulation of defense responses are dependent on signaling pathways mediated by JAs as well as other stress hormones (e.g. salicylic acid), generally those involving the transcriptional and post-transcriptional regulation of transcription factors via protein modification and epigenetic regulation. In addition to the typical model plant Arabidopsis (a dicotyledon), advances in genetics research have made rice a model monocot in which innovative pest control traits can be introduced and whose JA signaling pathway can be studied. In this review, we introduce the dynamic functions of JAs in plant defense strategy using defensive substances (e.g. indole alkaloids and terpenoid phytoalexins) and airborne signals (e.g. green leaf volatiles and volatile terpenes) in response to biotrophic and necrotrophic pathogens as well as above-ground and below-ground herbivores. We then discuss the important issue of how the mutualism of herbivorous arthropods with viruses or bacteria can cause cross-talk between JA and other phytohormones to counter the defense systems. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Pseudogymnoascus destructans: Causative Agent of White-Nose Syndrome in Bats Is Inhibited by Safe Volatile Organic Compounds.

PubMed

Padhi, Sally; Dias, Itamar; Korn, Victoria L; Bennett, Joan W

2018-04-10

White-nose syndrome (WNS) is caused by Pseudogymnoascus destructans , a psychrophilic fungus that infects hibernating bats and has caused a serious decline in some species. Natural aroma compounds have been used to control growth of fungal food storage pathogens, so we hypothesized that a similar strategy could work for control of P. destructans . The effectiveness of exposure to low concentrations of the vapor phase of four of these compounds was tested on mycelial plugs and conidiospores at temperatures of 5, 10 and 15 °C. Here we report the efficacy of vapor phase mushroom alcohol (1-octen-3-ol) for inhibiting mycelial and conidiospore growth of P. destructans at 0.4 and 0.8 µmol/mL and demonstrate that the R enantiomer of this compound is more effective than the S enantiomer, supporting the finding that biological systems can be sensitive to stereochemistry. Further, we report that vapor phase leaf aldehyde ( trans -2-hexenal), a common aroma compound associated with cut grass odors and also the major volatile compound in extra virgin olive oil, is more effective than mushroom alcohol. At 0.05 µmol/mL, trans -2-hexenal is fungicidal to both conidiospores and mycelia of P. destructans .

Chemical characterization of organosulfates from the hydroxyl radical-initiated oxidation and ozonolysis of cis-3-hexen-1-ol

NASA Astrophysics Data System (ADS)

Barbosa, Thais S.; Riva, Matthieu; Chen, Yuzhi; da Silva, Cleyton M.; Ameida, Jose Claudino S.; Zhang, Zhenfa; Gold, Avram; Arbilla, Graciela; Bauerfeldt, Glauco F.; Surratt, Jason D.

2017-08-01

Cis-3-hexen-1-ol (cis-HXO) is a green leaf volatile emitted from plants under stress and belongs to an important class of biogenic volatile organic compounds. In this study, we have investigated the potential formation of organosulfates (OSs) from the hydroxyl radical (OH)-initiated oxidation and ozonolysis of cis-HXO using either non-acidified or acidified sulfate seed aerosols under different relative humidity (RH) conditions. For selected ozonolysis experiments, an OH scavenger was utilized. Ultra performance liquid chromatography interfaced to high-resolution quadrupole time-of-flight mass spectrometry with electrospray ionization (UPLC/ESI-HR-Q-TOFMS) was used to characterize cis-HXO-derived secondary organic aerosol (SOA) formation. Chemical characterization of cis-HXO-derived SOA products reveals that OSs were generated in significant quantity from multiphase chemistry of gas-phase oxidation products of cis-HXO. Ambient fine aerosol (PM2.5) samples collected from Rio de Janeiro, Brazil, were also analyzed. Seven cis-HXO-derived OSs identified in the lab study with molecular weights 154, 186, 170, 210, 212, 226 and 270 were also found in the PM2.5 samples collected in Brazil. This study provides direct evidence that the oxidation of cis-HXO by OH and O3 yields biogenic SOA through the formation of polar OSs.

Volatiles produced by soil-borne endophytic bacteria increase plant pathogen resistance and affect tritrophic interactions

PubMed Central

Ton, Jurriaan; Brandenburg, Anna; Karlen, Danielle; Zopfi, Jakob; Turlings, Ted C. J.

2014-01-01

Volatile organic compounds (VOCs) released by soil microorganisms influence plant growth and pathogen resistance. Yet, very little is known about their influence on herbivores and higher trophic levels. We studied the origin and role of a major bacterial VOC, 2,3-butanediol (2,3-BD), on plant growth, pathogen and herbivore resistance, and the attraction of natural enemies in maize. One of the major contributors to 2,3-BD in the headspace of soil-grown maize seedlings was identified as Enterobacter aerogenes, an endophytic bacterium that colonizes the plants. The production of 2,3-BD by E. aerogenes rendered maize plants more resistant against the Northern corn leaf blight fungus Setosphaeria turcica. On the contrary, E. aerogenes-inoculated plants were less resistant against the caterpillar Spodoptera littoralis. The effect of 2,3-BD on the attraction of the parasitoid Cotesia marginiventris was more variable: 2,3-BD application to the headspace of the plants had no effect on the parasitoids, but application to the soil increased parasitoid attraction. Furthermore, inoculation of seeds with E. aerogenes decreased plant attractiveness, whereas inoculation of soil with a total extract of soil microbes increased parasitoid attraction, suggesting that the effect of 2,3-BD on the parasitoid is indirect and depends on the composition of the microbial community. PMID:24127750

Generation of autotetraploid plant of ginger (Zingiber officinale Rosc.) and its quality evaluation

PubMed Central

Kun-Hua, Wei; Jian-Hua, Miao; He-Ping, Huang; Shan-Lin, Gao

2011-01-01

Background: Zingiber officinale Rosc. is not only an important medical plant in China, but also one of the most commonly used plant spices around the world. Early researches in Z. officinale Rosc. were focused on rapid propagation, germplasm preservation, and somatic embryogenesis, only a few reports focused on the generation of tetraploid ginger plants with colchicines treatment in vitro. Materials and Methods: The adventitious buds were submerged into different concentrations of colchicine water solution for different time to induce polyploid plants, and the induced buds were identified by root-tip chromosome determination and stomatal apparatus observation. Eighteen selected tetraploid lines were transferred to the field, and the leaf characteristics, rhizome yield, contents of volatile oil and gingerol were respectively evaluated to provide evidence of high-yield and good qualities of tetraploid ginger. Results: The induction rate reached as high as 33.3% of treated buds. More than 48 lines of autotetraploid plants were obtained. All tetraploid plants showed typical polyploidy characteristics. All of the 18 selected tetraploid lines possessed higher rhizome yield and overall productivity of volatile oil and gingerol than those of the control. Conclusion: Five elite lines have been selected for further selection and breeding new varieties for commercial production in agricultural production. PMID:21969790

Relevance of chemistry to conservation of isolated populations: the case of volatile leaf components of Dicerandra mints.

PubMed Central

McCormick, K D; Deyrup, M A; Menges, E S; Wallace, S R; Meinwald, J; Eisner, T

1993-01-01

Chemical analysis of the essential oils of four congeneric species of mint plant (Dicerandra spp.) endemic to Florida revealed a pattern of chemical similarity and dissimilarity that would not have been predicted on morphological or geographic criteria. Dicerandra christmanii differs fundamentally from its congeners in that it produces fewer compounds and lacks the acyclic components. Yet D. christmanii is more closely similar to Dicerandra frutescens than to other Dicerandra species in morphological characters and geographic range. We conclude that the potential chemical value of a species should not be prejudged on the basis of nonchemical characters and that designation of surplus plant populations by conservationists should be resisted unless such populations have also been chemically studied. Images Fig. 2 PMID:8356072

Induction of Systemic Resistance against Insect Herbivores in Plants by Beneficial Soil Microbes

PubMed Central

Rashid, Md. Harun-Or; Chung, Young R.

2017-01-01

Soil microorganisms with growth-promoting activities in plants, including rhizobacteria and rhizofungi, can improve plant health in a variety of different ways. These beneficial microbes may confer broad-spectrum resistance to insect herbivores. Here, we provide evidence that beneficial microbes modulate plant defenses against insect herbivores. Beneficial soil microorganisms can regulate hormone signaling including the jasmonic acid, ethylene and salicylic acid pathways, thereby leading to gene expression, biosynthesis of secondary metabolites, plant defensive proteins and different enzymes and volatile compounds, that may induce defenses against leaf-chewing as well as phloem-feeding insects. In this review, we discuss how beneficial microbes trigger induced systemic resistance against insects by promoting plant growth and highlight changes in plant molecular mechanisms and biochemical profiles. PMID:29104585

Volatile organic compound emission profiles of four common arctic plants

NASA Astrophysics Data System (ADS)

Vedel-Petersen, Ida; Schollert, Michelle; Nymand, Josephine; Rinnan, Riikka

2015-11-01

The biogenic volatile organic compound (BVOC) emissions from plants impact atmosphere and climate. The species-specific emissions, and thereby the atmospheric impact, of many plant species are still unknown. Knowledge of BVOC emission from arctic plants is particularly limited. The vast area and relatively high leaf temperature give the Arctic potential for emissions that cannot be neglected. This field study aimed to elucidate the BVOC emission profiles for four common arctic plant species in their natural environment during the growing season. BVOCs were sampled from aboveground parts of Empetrum hermaphroditum, Salix glauca, Salix arctophila and Betula nana using the dynamic enclosure technique and collection of volatiles in adsorbent cartridges, analyzed by gas chromatography-mass spectrometry. Sampling occurred three times: in late June/early July, in mid-July and in early August. E. hermaphroditum emitted the least BVOCs, dominated by sesquiterpenes (SQTs) and non-isoprenoid BVOCs. The Salix spp. emitted the most, dominated by isoprene. The emissions of B. nana were composed of about two-thirds non-isoprenoid BVOCs, with moderate amounts of monoterpenes (MTs) and SQTs. The total B. nana emissions and the MT and SQT emissions standardized to 30 °C were highest in the first measurement in early July, while the other species had the highest emissions in the last measurement in early August. As climate change is expected to increase plant biomass and change vegetation composition in the Arctic, the BVOC emissions from arctic ecosystems will also change. Our results suggest that if the abundance of deciduous shrubs like Betula and Salix spp. increases at the expense of slower growing evergreens like E. hermaphroditum, there is the potential for increased emissions of isoprene, MTs and non-isoprenoid BVOCs in the Arctic.

Differential controls by climate and physiology over the emission rates of biogenic volatile organic compounds from mature trees in a semi-arid pine forest.

PubMed

Eller, Allyson S D; Young, Lindsay L; Trowbridge, Amy M; Monson, Russell K

2016-02-01

Drought has the potential to influence the emission of biogenic volatile organic compounds (BVOCs) from forests and thus affect the oxidative capacity of the atmosphere. Our understanding of these influences is limited, in part, by a lack of field observations on mature trees and the small number of BVOCs monitored. We studied 50- to 60-year-old Pinus ponderosa trees in a semi-arid forest that experience early summer drought followed by late-summer monsoon rains, and observed emissions for five BVOCs-monoterpenes, methylbutenol, methanol, acetaldehyde and acetone. We also constructed a throughfall-interception experiment to create "wetter" and "drier" plots. Generally, trees in drier plots exhibited reduced sap flow, photosynthesis, and stomatal conductances, while BVOC emission rates were unaffected by the artificial drought treatments. During the natural, early summer drought, a physiological threshold appeared to be crossed when photosynthesis ≅2 μmol m(-2) s(-1) and conductance ≅0.02 mol m(-2) s(-1). Below this threshold, BVOC emissions are correlated with leaf physiology (photosynthesis and conductance) while BVOC emissions are not correlated with other physicochemical factors (e.g., compound volatility and tissue BVOC concentration) that have been shown in past studies to influence emissions. The proportional loss of C to BVOC emission was highest during the drought primarily due to reduced CO2 assimilation. It appears that seasonal drought changes the relations among BVOC emissions, photosynthesis and conductance. When drought is relaxed, BVOC emission rates are explained mostly by seasonal temperature, but when seasonal drought is maximal, photosynthesis and conductance-the physiological processes which best explain BVOC emission rates-decline, possibly indicating a more direct role of physiology in controlling BVOC emission.

Differences in photosynthesis and isoprene emission in post oak (Quercus stellata) and sweetgum (Liquidambar styraciflua) trees along an urban-to-rural gradient in Texas

NASA Astrophysics Data System (ADS)

Crossett, C.; Lahr, E.; Haas, G.; Schade, G. W.

2014-12-01

Many plants produce isoprene, a volatile organic compound that can mitigate damage to photosynthetic systems during short- or long-term increases in leaf temperature. After its production within leaves, isoprene is emitted to the atmosphere and influences regional atmospheric chemistry. Here, we use an urban-to-rural gradient to explore future effects of climate change on tree eco-physiology and feedbacks to atmospheric chemistry. Urban areas mimic many of the conditions expected to occur in the future; in particular, cities have warmer temperatures due to the urban heat island (UHI) effect, and less water availability relative to rural areas. Along a 90 km urban-to-rural gradient, we measured photosynthesis and isoprene emission from trees at three sites in eastern Texas: Houston (urban), The Woodlands (suburban) and Sam Houston National Forest (rural). Isoprene emission from post oak (Quercus stellata) was higher in Houston than the other sites, and when leaf temperatures were increased above ambient conditions, trees produced more isoprene. Leaves produced more isoprene at high leaf temperatures in early summer than in late summer, suggesting gradual acclimation of photosynthetic processes over the course of the summer. We also found that sweetgum (Liquidambar styraciflua) emitted more isoprene than post oak, but when leaf temperatures were increased, isoprene emission was exhausted more quickly in sweetgum relative to post oak. At the same time, post oak maintained higher levels of photosynthesis seasonally and during short-term temperature increases. Both post oak and sweetgum are significant isoprene emitters and represent approximately two and four percent crown cover in the United States, respectively. Our results suggest that in a warming climate, we can expect trees to produce more isoprene seasonally and in response to short-term temperature extremes, and that species-specific differences in photosynthesis and isoprene emission may play an important role in forest dynamics, particularly in long-term forest growth and carbon storage. Further exploration of the interactive effect of increased CO2, temperature, and drought on tree physiology will improve our understanding of forest dynamics and forest-climate feedbacks.

SOA Formation Potential of Emissions from Soil and Leaf Litter

NASA Astrophysics Data System (ADS)

Faiola, C. L.; Vanderschelden, G. S.; Wen, M.; Cobos, D. R.; Jobson, B. T.; VanReken, T. M.

2013-12-01

In the United States, emissions of volatile organic compounds (VOCs) from natural sources exceed all anthropogenic sources combined. VOCs participate in oxidative chemistry in the atmosphere and impact the concentrations of ozone and particulate material. The formation of secondary organic aerosol (SOA) is particularly complex and is frequently underestimated using state-of-the-art modeling techniques. We present findings that suggest emissions of important SOA precursors from soil and leaf litter are higher than current inventories would suggest, particularly under conditions typical of Fall and Spring. Soil and leaf litter samples were collected at Big Meadow Creek from the University of Idaho Experimental Forest. The dominant tree species in this area of the forest are ponderosa pine, Douglas-fir, and western larch. Samples were transported to the laboratory and housed within a 0.9 cubic meter Teflon dynamic chamber where VOC emissions were continuously monitored with a GC-FID-MS and PTR-MS. Aerosol was generated from soil and leaf litter emissions by pumping the emissions into a 7 cubic meter Teflon aerosol growth chamber where they were oxidized with ozone in the absence of light. The evolution of particle microphysical and chemical characteristics was monitored over the following eight hours. Particle size distribution and chemical composition were measured with a SMPS and HR-ToF-AMS respectively. Monoterpenes dominated the emission profile with emission rates up to 283 micrograms carbon per meter squared per hour. The dominant monoterpenes emitted were beta-pinene, alpha-pinene, and delta-3-carene in descending order. The composition of the SOA produced was similar to biogenic SOA formed from oxidation of ponderosa pine emissions and alpha-pinene. Measured soil/litter monoterpene emission rates were compared with modeled canopy emissions. Results suggest that during fall and spring when tree emissions are lower, monoterpene emissions within forests may be dominated by soil/litter emissions--soil/litter monoterpene emissions in spring could contribute up to 63% of total forest emissions. If this is the case, a significant portion of total forest monoterpene emission rates would be controlled by factors that affect soil/litter emissions rather than factors that affect plant emissions.

Fluorescence Across Space and Time (2017 FAST Campaign): Investigating the multiscale links between fluorescence and photosynthesis

NASA Astrophysics Data System (ADS)

Porcar-Castell, A.; Atherton, J.; Rajewicz, P. A.; Riikonen, A.; Gebre, S.; Liu, W.; Aalto, J.; Bendoula, R.; Burkart, A.; Chen, H.; Erkkilä, K. M.; Feret, J. B.; Fernández-Marín, B.; García-Plazaola, J. I.; Hakala, T.; Hartikainen, S.; Honkavaara, E.; Ihalainen, J.; Julitta, T.; Kolari, P.; Kooijmans, L.; Levula, J.; Loponen, M.; Mac Arthur, A.; Magney, T.; Maseyk, K. S.; Mottus, M.; Neimane, S.; Oksa, E.; Osterman, G. B.; Robinson, I.; Robson, M. T.; Sabater, N.; Solanki, T.; Tikkanen, M.; Mäkipää, R.; Aro, E. M.; Rascher, U.; Frankenberg, C.; Kulmala, M. T.; Vesala, T.; Back, J. K.

2017-12-01

The use of solar-induced chlorophyll fluorescence (ChlF) as a tracer of photosynthesis is rapidly expanding with increasing numbers of measurements from towers, drones, aircrafts, or satellites. But how to integrate all the informative potential of these multiscale datasets? The connection between ChlF and photosynthesis takes place via multiple mechansisms that depend on the scale. At the leaf level, diurnal variations in ChlF may indicate changes in photochemical or non-photochemical quenching processes, whereas seasonal variations may indicate changes in the protein structure or pigment composition of the photosynthetic apparatus. At the canopy level, variations in ChlF may also reflect changes in total leaf area, canopy structure, species composition, changes in illumination or sun-target-sensor geometry, background properties, etc. At the pixel level, the dynamics of the atmosphere are also important. It is therefore essential to characterize the impact of factors that control ChlF and photosynthesis at each scale. A combination of multiscale and continuous experimentation and modelling is probably the best option to close the remaining knowledge gaps. The goal of the FAST campaign was to characterize the processes that control the ChlF signal dynamics at each scale, establishing a comprehensive dataset for multiscale hypothesis and model validation. The campaign took place in Hyytiälä (Southern Finland) and lasted for 6 months. Measurements expanded from the molecular to the satellite pixel level and from the picosecond to the seasonal scale, including multiple species, and providing a unique optical and phenomenological record of the multiscale spring recovery of photosynthesis in a boreal forest. Amongst others we measured and registered: leaf ChlF spectra, OJIP kinetics, PSI and PSII activity, photosynthetic gas exchange, carbonyl sulphide (COS), volatile organic compounds (VOCs), total leaf absorption, pigment concentrations, photosynthetic proteins, fluorescence lifetime, canopy SIF, CO2, water, COS, and VOC fluxes, as well as vertical profiles of forest SIF using a drone and target OCO-2 observations at 1x2km pixel resolution. We here present preliminary results from the FAST campaign which emphasize the variability and role of different controls across scales.

The Effect of Bamboo Leaf Extract Solution and Sodium Copper Chlorophyllin Solution on Growth and Volatile Sulfur Compounds Production of Oral Malodor Associated Some Anaerobic Periodontal Bacteria

PubMed Central

Majbauddin, Abir; Kodani, Isamu; Ryoke, Kazuo

2015-01-01

Background Bamboo leaf extract solution (BLES) and sodium copper chlorophyllin solution (SCCS) are known for their anti-oxidant activities. Oral malodor is often related with periodontal pathogens. The present study was undertaken to investigate the anti-bacterial effect of both BLES and SCCS on anaerobic periodontal bacteria producing oral malodorous volatile sulfur compounds (VSC). Methods Porphyromonas gingivalis W83 (PG), Prevotella intermidai TDC19B (PI), Fusobacterium nucleatum ATCC25586 (FN) and Prevotella nigrescence ATCC33563 (PN) were investigated as oral isolated bacteria. VSC production ability of the oral strains was investigated by gas chromatography. With serial dilution of BLES or SCCS, the strains PG, PI, FN or PN were cultured anaerobically with AnaeroPack at 37 ℃ for 3 days. For the determination of anti-bacterial action of BLES or SCCS, the inoculum was cultured with original concentrations of BLES 0.16% (w/v) or SCCS 0.25% (w/v). Results Gas chromatography exhibited that all strains, PG, PI, FN and PN were responsible for producing a high range of H2S and a moderate range of CH3SH. Anti-bacterial effect of BLES or SCCS on the strains was observed. Inhibition of BLES or SCCS on the strains was revealed as concentration dependent. BLES or SCCS inhibited bacterial proliferation at higher concentrations (PG; 0.04% BLES or 0.03% SCCS, PI; 0.002% BLES or 0.03% SCCS, FN; 0.005% BLES or 0.01% SCCS, PN; 0.01% BLES or 0.015% SCCS). No viable bacterial colony observed at original concentration of BLES 0.16% or SCCS 0.25%. Strain growth was eliminated from inhibition at lower concentrations (PG; 0.02% BLES or 0.015% SCCS, PI; 0.001% BLES or 0.015% SCCS, FN; 0.002% BLES or 0.007% SCCS, PN; 0.005% BLES or 0.007% SCCS). Conclusion High concentrations of both BLES (0.16%) and SCCS (0.25%) show superior inhibiting capability on all four oral malodor associated periodontal anaerobes during testing, suggesting that these compounds might have a beneficial effect on oral health care. PMID:26538799

Volatile organic compounds from vegetation in southern Yunnan Province, China: Emission rates and some potential regional implications

NASA Astrophysics Data System (ADS)

Geron, Chris; Owen, Sue; Guenther, Alex; Greenberg, Jim; Rasmussen, Rei; Hui Bai, Jian; Li, Qing-Jun; Baker, Brad

Little information is currently available regarding emissions of biogenic volatile organic compounds (BVOCs) in southern Asia. To address the need for BVOC emission estimates in regional atmospheric chemistry simulations, 95 common plant species were screened for emissions of BVOC in and near the Xishuangbanna Tropical Biological Gardens in southern Yunnan Province, Peoples' Republic of China in February 2003. In situ measurements with leaf cuvettes and branch bag enclosures were used in combination with portable gas chromatography, flame ionization, photoionization, and mass spectral detection to identify and quantify BVOC emissions. Forty-four of the species examined emitted isoprene at rates exceeding 20 μg C g -1 (leaf dry weight) h -1. An emphasis was placed on the genus Ficus, which is important in the region and occupies a wide range of ecological niches. Several species in the footprint of a nearby flux tower were also examined. Several palm species and an abundant fern ( Cyclosorus parasiticus) emitted substantial amounts of isoprene, and probably accounted for observed daytime mean isoprene fluxes from the understory of a Hevea brasiliensis plantation of 1.0 and 0.15 mg C m -2 h -1 during the wet and dry seasons, respectively. These measurements verify that both the forest floor and canopy in this region can be sources of isoprene. Monoterpene emissions exceeded 1.0 μg-C g -1 (leaf dry weight) h -1 from only 4 of 38 species surveyed, including some Ficus species and H. brasiliensis. However most of the trees of the latter species were sparsely foliated due to dry season senescence, and emission factors are approximately an order of magnitude lower than those reported during the wet season. BVOC emission rates and physiology of many species are impacted by reduced moisture availability, especially Mangifera indica. South Asia is a region undergoing rapid landuse change and forest plantation establishment, with large increases in area of high BVOC-emitting species in the genera Bambusa, Elaeis, Eucalyptus, Hevea, Pinus, and Populus (among others). This could result in profound changes in atmospheric chemistry in these regions, for instance, terpene emissions from H. brasiliensis could increase wet season biogenic organic aerosol burdens by approximately a factor of 2 in the Xishuangbanna region. Increases in plantation area established with high isoprene emitting species, (e.g. Bambusa spp. and Eucalyptus spp.) are also projected for China and other parts of Southeast Asia in the near future. Thus, landcover change in South Asian landscapes is usually associated with large increases in BVOC flux with the potential to alter the atmospheric chemical composition and air quality over this rapidly developing region.

The Amazonian Floodplains, an ecotype with challenging questions on volatile organic compound (VOC) emissions

NASA Astrophysics Data System (ADS)

Kesselmeier, J.

2012-12-01

Volatile organic compound (VOC) emissions are affected by a variety of biotic and abiotic factors such as light intensity, temperature, CO2 and drought. Another factor usually overlooked but very important for the tropical rainforest in Amazonia is regular flooding. According to recent estimates, the total Amazonian floodplain area easily ranges up to 700,000 km^2, including whitewater river floodplains (várzea) blackwater regions (igapó) and further clearwater regions. Regarding the total Amazonian wetlands the area sums up to more than 2.000.000 km^2, i.e. 30% of Amazonia. To survive the flooding periods causing anoxic conditions for the root system of up to several months, vegetation has developed several morphological, anatomical and physiological strategies. One is to switch over the root metabolism to fermentation, thus producing ethanol as one of the main products. Ethanol is a toxic metabolite which is transported into the leaves by the transpiration stream. From there it can either be directly emitted into the atmosphere, or can be re-metabolized to acetaldehyde and/or acetate. All of these compounds are volatile enough to be partly released into the atmosphere. We observed emissions of ethanol, acetaldehyde and acetic acid under root anoxia. Furthermore, plant stress induced by flooding also affected leaf primary physiological processes as well as other VOC emissions such as the release of isoprenoids and other volatiles. For example, Hevea spruceana could be identified as a monoterpene emitting tree species behaving differently upon anoxia depending on the origin, with increasing emissions of the species from igapó and decreasing with the corresponding species from várzea. Contrasting such short term inundations, studies of VOC emissions under long term conditions (2-3 months) did not confirm the ethanol/acetaldehyde emissions, whereas emissions of other VOC species decreased considerably. These results demonstrate that the transfer of our knowledge based on short-term experiments is risky being transferred to an ecotype which is governed under natural conditions by long term flooding. Furthermore, contrasting such experiments with usually young trees (saplings or a few years old) nothing is known about the emission behavior of adult trees under field conditions.

Red:far-red light conditions affect the emission of volatile organic compounds from barley (Hordeum vulgare), leading to altered biomass allocation in neighbouring plants

PubMed Central

Kegge, Wouter; Ninkovic, Velemir; Glinwood, Robert; Welschen, Rob A. M.; Voesenek, Laurentius A. C. J.; Pierik, Ronald

2015-01-01

Background and Aims Volatile organic compounds (VOCs) play various roles in plant–plant interactions, and constitutively produced VOCs might act as a cue to sense neighbouring plants. Previous studies have shown that VOCs emitted from the barley (Hordeum vulgare) cultivar ‘Alva’ cause changes in biomass allocation in plants of the cultivar ‘Kara’. Other studies have shown that shading and the low red:far-red (R:FR) conditions that prevail at high plant densities can reduce the quantity and alter the composition of the VOCs emitted by Arabidopsis thaliana, but whether this affects plant–plant signalling remains unknown. This study therefore examines the effects of far-red light enrichment on VOC emissions and plant–plant signalling between ‘Alva’ and ‘Kara’. Methods The proximity of neighbouring plants was mimicked by supplemental far-red light treatment of VOC emitter plants of barley grown in growth chambers. Volatiles emitted by ‘Alva’ under control and far-red light-enriched conditions were analysed using gas chromatography–mass spectrometry (GC-MS). ‘Kara’ plants were exposed to the VOC blend emitted by the ‘Alva’ plants that were subjected to either of the light treatments. Dry matter partitioning, leaf area, stem and total root length were determined for ‘Kara’ plants exposed to ‘Alva’ VOCs, and also for ‘Alva’ plants exposed to either control or far-red-enriched light treatments. Key Results Total VOC emissions by ‘Alva’ were reduced under low R:FR conditions compared with control light conditions, although individual volatile compounds were found to be either suppressed, induced or not affected by R:FR. The altered composition of the VOC blend emitted by ‘Alva’ plants exposed to low R:FR was found to affect carbon allocation in receiver plants of ‘Kara’. Conclusions The results indicate that changes in R:FR light conditions influence the emissions of VOCs in barley, and that these altered emissions affect VOC-mediated plant–plant interactions. PMID:25851141

Red:far-red light conditions affect the emission of volatile organic compounds from barley (Hordeum vulgare), leading to altered biomass allocation in neighbouring plants.

PubMed

Kegge, Wouter; Ninkovic, Velemir; Glinwood, Robert; Welschen, Rob A M; Voesenek, Laurentius A C J; Pierik, Ronald

2015-05-01

Volatile organic compounds (VOCs) play various roles in plant-plant interactions, and constitutively produced VOCs might act as a cue to sense neighbouring plants. Previous studies have shown that VOCs emitted from the barley (Hordeum vulgare) cultivar 'Alva' cause changes in biomass allocation in plants of the cultivar 'Kara'. Other studies have shown that shading and the low red:far-red (R:FR) conditions that prevail at high plant densities can reduce the quantity and alter the composition of the VOCs emitted by Arabidopsis thaliana, but whether this affects plant-plant signalling remains unknown. This study therefore examines the effects of far-red light enrichment on VOC emissions and plant-plant signalling between 'Alva' and 'Kara'. The proximity of neighbouring plants was mimicked by supplemental far-red light treatment of VOC emitter plants of barley grown in growth chambers. Volatiles emitted by 'Alva' under control and far-red light-enriched conditions were analysed using gas chromatography-mass spectrometry (GC-MS). 'Kara' plants were exposed to the VOC blend emitted by the 'Alva' plants that were subjected to either of the light treatments. Dry matter partitioning, leaf area, stem and total root length were determined for 'Kara' plants exposed to 'Alva' VOCs, and also for 'Alva' plants exposed to either control or far-red-enriched light treatments. Total VOC emissions by 'Alva' were reduced under low R:FR conditions compared with control light conditions, although individual volatile compounds were found to be either suppressed, induced or not affected by R:FR. The altered composition of the VOC blend emitted by 'Alva' plants exposed to low R:FR was found to affect carbon allocation in receiver plants of 'Kara'. The results indicate that changes in R:FR light conditions influence the emissions of VOCs in barley, and that these altered emissions affect VOC-mediated plant-plant interactions. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

In vitro production of M. × piperita not containing pulegone and menthofuran.

PubMed

Bertoli, Alessandra; Leonardi, Michele; Krzyzanowska, Justyna; Oleszek, Wieslaw; Pistelli, Luisa

2012-01-01

The essential oils (EOs) and static headspaces (HSs) of in vitro plantlets and callus of Mentha x piperita were characterized by GC-MS analysis. Leaves were used as explants to induce in vitro plant material. The EO yields of the in vitro biomass were much lower (0.1% v/w) than those of the parent plants (2% v/w). Many typical mint volatiles were emitted by the in vitro production, but the callus and in vitro plantelet EOs were characterized by the lack of both pulegone and menthofuran. This was an important difference between in vitro and in vivo plant material as huge amounts of pulegone and menthofuran may jeopardise the safety of mint essential oil. Regarding the other characteristic volatiles, menthone was present in reduced amounts (2%) in the in vitro plantlets and was not detected in the callus, even if it represented the main constituent of the stem and leaf EOs obtained from the cultivated mint (26% leaves; 33% stems). The M. piperita callus was characterized by menthol (9%) and menthone (2%), while the in vitro plantlet EO showed lower amounts of both these compounds in favour of piperitenone oxide (45%). Therefore, the established callus and in vitro plantlets showed peculiar aromatic profiles characterized by the lack of pulegone and menthofuran which have to be monitored in the mint oil for their toxicity.

Plant-specific volatile organic compound emission rates from young and mature leaves of Mediterranean vegetation

NASA Astrophysics Data System (ADS)

Bracho-Nunez, Araceli; Welter, Saskia; Staudt, Michael; Kesselmeier, Jürgen

2011-08-01

The seasonality of vegetation, i.e., developmental stages and phenological processes, affects the emission of volatile organic compounds (VOCs). Despite the potential significance, the contributions of seasonality to VOC emission quality and quantity are not well understood and are therefore often ignored in emission simulations. We investigated the VOC emission patterns of young and mature leaves of several Mediterranean plant species in relation to their physiological and developmental changes during the growing period and estimated Es. Foliar emissions of isoprenoids and oxygenated VOCs like methanol and acetone were measured online by means of a proton transfer reaction mass spectrometer (PTR-MS) and offline with gas chromatography coupled with a mass spectrometer and flame ionization detector. The results suggest that VOC emission is a developmentally regulated process and that quantitative and qualitative variability is plant species specific. Leaf ontogeny clearly influenced both the VOC Es and the relative importance of different VOCs. Methanol was the major compound contributing to the sum of target VOC emissions in young leaves (11.8 ± 10.4 μg g-1 h-1), while its contribution was minor in mature leaves (4.1 ± 4.1 μg g-1 h-1). Several plant species showed a decrease or complete subsidence of monoterpene, sesquiterpene, and acetone emissions upon maturity, perhaps indicating a potential response to the higher defense demands of young emerging leaves.

Response of Plutella xylostella and its parasitoid Cotesia plutellae to volatile compounds.

PubMed

Ibrahim, Mohamed A; Nissinen, Anne; Holopainen, Jarmo K

2005-09-01

The effects of limonene, a mixture of limonene + carvone (1:1, v/v), and methyl jasmonate (MeJA) on diamondback moth (DBM) (Plutella xylostella L.) oviposition, larval feeding, and the behavior of its larval parasitoid Cotesia plutellae (Kurdjumov) with cabbage (Brassica oleracea L. ssp. capitata, cvs. Rinda and Lennox) and broccoli (B. oleracea subsp. Italica cv Lucky) were tested. Limonene showed no deterrent effect on DBM when plants were sprayed with or exposed to limonene, although there was a cultivar difference. A mixture of limonene and carvone released from vermiculite showed a significant repellent effect, reducing the number of eggs laid on the cabbages. MeJA treatment reduced the relative growth rate (RGR) of larvae on cv Lennox leaves. In Y-tube olfactometer tests, C. plutellae preferred the odors of limonene and MeJA to filtered air. In cv Lennox, the parasitoid preferred DBM-damaged plants with limonene to such plants without limonene. C. plutellae females were repelled by the mixture of limonene + carvone. In both cultivars, exogenous MeJA induced the emission of the sesquiterpene (E,E)-alpha-farnesene, the homoterpene (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), and green leaf volatile (Z)-3-hexenyl acetate + octanal. The attractive effect of limonene and MeJA predicts that these two compounds can be used in sustainable plant protection strategies in organic farming.

Leaf herbivory imposes fitness costs mediated by hummingbird and insect pollinators

PubMed Central

Whitehead, Susan; Amaya-Márquez, Marisol; Poveda, Katja

2017-01-01

Plant responses induced by herbivore damage can provide fitness benefits, but can also have important costs due to altered interactions with mutualist pollinators. We examined the effects of plant responses to herbivory in a hummingbird-pollinated distylous shrub, Palicourea angustifolia. Through a series of field experiments we investigated whether damage from foliar herbivores leads to a reduction in fruit set, influences floral visitation, or alters floral traits that may influence pollinator preference or pollinator efficiency. Foliar herbivory by a generalist grasshopper led to reduced fruit set in branches that were directly damaged as well as in adjacent undamaged branches on the same plant. Furthermore, herbivory resulted in reduced floral visitation from two common hummingbird species and two bee species. An investigation into the potential mechanisms behind reduced floral visitation in induced plants showed that foliar herbivore damage resulted in shorter styles and lower nectar volumes. This reduction in style length could reduce pollen deposition between different floral morphs that is required for optimal pollination in a distylous plant. We did not detect any differences in the volatile blends released by damaged and undamaged branches, suggesting that foliar herbivore-induced changes in floral morphology and rewards, and not volatile blends, are the primary mechanism mediating changes in visitation. Our results provide novel mechanisms for how plant responses induced by foliar herbivores can lead to ecological costs. PMID:29211805

Plants respond to leaf vibrations caused by insect herbivore chewing.

PubMed

Appel, H M; Cocroft, R B

2014-08-01

Plant germination and growth can be influenced by sound, but the ecological significance of these responses is unclear. We asked whether acoustic energy generated by the feeding of insect herbivores was detected by plants. We report that the vibrations caused by insect feeding can elicit chemical defenses. Arabidopsis thaliana (L.) rosettes pre-treated with the vibrations caused by caterpillar feeding had higher levels of glucosinolate and anthocyanin defenses when subsequently fed upon by Pieris rapae (L.) caterpillars than did untreated plants. The plants also discriminated between the vibrations caused by chewing and those caused by wind or insect song. Plants thus respond to herbivore-generated vibrations in a selective and ecologically meaningful way. A vibration signaling pathway would complement the known signaling pathways that rely on volatile, electrical, or phloem-borne signals. We suggest that vibration may represent a new long distance signaling mechanism in plant-insect interactions that contributes to systemic induction of chemical defenses.

Phytoremediation of ionic and methylmercury pollution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meagher, Richard B.

2010-04-28

Our long-term goal is to enable highly productive plant species to extract, resist, detoxify, and sequester the toxic elemental pollutants, like the heavy metal mercury. Our current working hypothesis is that transgenic plants controlling the transport, chemical speciation, electrochemical state. volatilization, and aboveground binding of mercury will: a) tolerate mercury and grow rapidly in mercury contaminated environments; b) prevent methylmercury from entering the food chain; c) remove mercury from polluted soil and water; and d) hyperaccumulate mercury in aboveground tissues for later harvest. Progress toward these specific aims is reported: to increase the transport of mercury into roots and tomore » aboveground vegetative organs; to increase biochemical sinks and storage for mercury in leaves; to increase leaf cell vacuolar storage of mercury; and to demonstrate that several stacked transgenes, when functioning in concert, enhance mercury resistance and hyperaccumulation to high levels.« less

Volatile-Mediated Effects Predominate in Paraburkholderia phytofirmans Growth Promotion and Salt Stress Tolerance of Arabidopsis thaliana

PubMed Central

Ledger, Thomas; Rojas, Sandy; Timmermann, Tania; Pinedo, Ignacio; Poupin, María J.; Garrido, Tatiana; Richter, Pablo; Tamayo, Javier

2016-01-01

Abiotic stress has a growing impact on plant growth and agricultural activity worldwide. Specific plant growth promoting rhizobacteria have been reported to stimulate growth and tolerance to abiotic stress in plants, and molecular mechanisms like phytohormone synthesis and 1-aminocyclopropane-1-carboxylate deamination are usual candidates proposed to mediate these bacterial effects. Paraburkholderia phytofirmans PsJN is able to promote growth of several plant hosts, and improve their tolerance to chilling, drought and salinity. This work investigated bacterial determinants involved in PsJN stimulation of growth and salinity tolerance in Arabidopsis thaliana, showing bacteria enable plants to survive long-term salinity treatment, accumulating less sodium within leaf tissues relative to non-inoculated controls. Inactivation of specific bacterial genes encoding ACC deaminase, auxin catabolism, N-acyl-homoserine-lactone production, and flagellin synthesis showed these functions have little influence on bacterial induction of salinity tolerance. Volatile organic compound emission from strain PsJN was shown to reproduce the effects of direct bacterial inoculation of roots, increasing plant growth rate and tolerance to salinity evaluated both in vitro and in soil. Furthermore, early exposure to VOCs from P. phytofirmans was sufficient to stimulate long-term effects observed in Arabidopsis growth in the presence and absence of salinity. Organic compounds were analyzed in the headspace of PsJN cultures, showing production of 2-undecanone, 7-hexanol, 3-methylbutanol and dimethyl disulfide. Exposure of A. thaliana to different quantities of these molecules showed that they are able to influence growth in a wide range of added amounts. Exposure to a blend of the first three compounds was found to mimic the effects of PsJN on both general growth promotion and salinity tolerance. To our knowledge, this is the first report on volatile compound-mediated induction of plant abiotic stress tolerance by a Paraburkholderia species. PMID:27909432

Transgenic Bt Rice Does Not Challenge Host Preference of the Target Pest of Rice Leaffolder, Cnaphalocrocis medinalis (Lepidoptera: Pyralidae)

PubMed Central

Sun, Xiao; Zhou, Wen; Liu, Hao; Zhang, Aijun; Ai, Chao-Ren; Zhou, Shuang-Shuang; Zhou, Chang-Xiang; Wang, Man-Qun

2013-01-01

Background Transgenic Bt rice line T2A-1 expresses a synthesized cry2A gene that shows high resistance to Lepidoptera pests, including Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae). Plant volatile orientation cues and the physical characteristics of the leaf surface play key roles in host location or host-plant acceptance of phytophagous insects. These volatile compounds and physical traits may become altered in Bt rice and it is not known whether this influences the behavior of C. medinalis when searching for oviposition sites. Results The results of electronic nose analysis showed that the Radar map of Bt rice cultivars was analogous to the non- Bt rice cultivars at each growing stage. PCA analysis was able to partly discriminate between some of the Bt vs. non-Bt rice sensors, but could not to separate Bt cultivars from non-Bt cultivars. The total ion chromatogram between Bt and non-Bt rice cultivars at the seedling, booting and tillering stages were similar and 25 main compounds were identified by GC-MS. For most compounds, there was no significant difference in compound quantities between Bt and non-Bt rice cultivars at equivalent growth stages. The densities of the tubercle papicles and the trichomes on the upper and lower surfaces were statistically equal in Bt and non-Bt rice. The target pest, C. medinalis, was attracted to host rice plants, but it could not distinguish between the transgenic and the isogenic rice lines. Conclusions There were no significant differences between the Bt rice line, T2A-1 and the non-Bt rice for volatiles produced or in its physical characteristics and there were no negative impacts on C. medinalis oviposition behavior. These results add to the mounting evidence that Bt rice has no negative impact on the target insect oviposition behavior. PMID:24244410

An elm EST database for identifying leaf beetle egg-induced defense genes

PubMed Central

2012-01-01

Background Plants can defend themselves against herbivorous insects prior to the onset of larval feeding by responding to the eggs laid on their leaves. In the European field elm (Ulmus minor), egg laying by the elm leaf beetle ( Xanthogaleruca luteola) activates the emission of volatiles that attract specialised egg parasitoids, which in turn kill the eggs. Little is known about the transcriptional changes that insect eggs trigger in plants and how such indirect defense mechanisms are orchestrated in the context of other biological processes. Results Here we present the first large scale study of egg-induced changes in the transcriptional profile of a tree. Five cDNA libraries were generated from leaves of (i) untreated control elms, and elms treated with (ii) egg laying and feeding by elm leaf beetles, (iii) feeding, (iv) artificial transfer of egg clutches, and (v) methyl jasmonate. A total of 361,196 ESTs expressed sequence tags (ESTs) were identified which clustered into 52,823 unique transcripts (Unitrans) and were stored in a database with a public web interface. Among the analyzed Unitrans, 73% could be annotated by homology to known genes in the UniProt (Plant) database, particularly to those from Vitis, Ricinus, Populus and Arabidopsis. Comparative in silico analysis among the different treatments revealed differences in Gene Ontology term abundances. Defense- and stress-related gene transcripts were present in high abundance in leaves after herbivore egg laying, but transcripts involved in photosynthesis showed decreased abundance. Many pathogen-related genes and genes involved in phytohormone signaling were expressed, indicative of jasmonic acid biosynthesis and activation of jasmonic acid responsive genes. Cross-comparisons between different libraries based on expression profiles allowed the identification of genes with a potential relevance in egg-induced defenses, as well as other biological processes, including signal transduction, transport and primary metabolism. Conclusion Here we present a dataset for a large-scale study of the mechanisms of plant defense against insect eggs in a co-evolved, natural ecological plant–insect system. The EST database analysis provided here is a first step in elucidating the transcriptional responses of elm to elm leaf beetle infestation, and adds further to our knowledge on insect egg-induced transcriptomic changes in plants. The sequences identified in our comparative analysis give many hints about novel defense mechanisms directed towards eggs. PMID:22702658

An elm EST database for identifying leaf beetle egg-induced defense genes.

PubMed

Büchel, Kerstin; McDowell, Eric; Nelson, Will; Descour, Anne; Gershenzon, Jonathan; Hilker, Monika; Soderlund, Carol; Gang, David R; Fenning, Trevor; Meiners, Torsten

2012-06-15

Plants can defend themselves against herbivorous insects prior to the onset of larval feeding by responding to the eggs laid on their leaves. In the European field elm (Ulmus minor), egg laying by the elm leaf beetle ( Xanthogaleruca luteola) activates the emission of volatiles that attract specialised egg parasitoids, which in turn kill the eggs. Little is known about the transcriptional changes that insect eggs trigger in plants and how such indirect defense mechanisms are orchestrated in the context of other biological processes. Here we present the first large scale study of egg-induced changes in the transcriptional profile of a tree. Five cDNA libraries were generated from leaves of (i) untreated control elms, and elms treated with (ii) egg laying and feeding by elm leaf beetles, (iii) feeding, (iv) artificial transfer of egg clutches, and (v) methyl jasmonate. A total of 361,196 ESTs expressed sequence tags (ESTs) were identified which clustered into 52,823 unique transcripts (Unitrans) and were stored in a database with a public web interface. Among the analyzed Unitrans, 73% could be annotated by homology to known genes in the UniProt (Plant) database, particularly to those from Vitis, Ricinus, Populus and Arabidopsis. Comparative in silico analysis among the different treatments revealed differences in Gene Ontology term abundances. Defense- and stress-related gene transcripts were present in high abundance in leaves after herbivore egg laying, but transcripts involved in photosynthesis showed decreased abundance. Many pathogen-related genes and genes involved in phytohormone signaling were expressed, indicative of jasmonic acid biosynthesis and activation of jasmonic acid responsive genes. Cross-comparisons between different libraries based on expression profiles allowed the identification of genes with a potential relevance in egg-induced defenses, as well as other biological processes, including signal transduction, transport and primary metabolism. Here we present a dataset for a large-scale study of the mechanisms of plant defense against insect eggs in a co-evolved, natural ecological plant-insect system. The EST database analysis provided here is a first step in elucidating the transcriptional responses of elm to elm leaf beetle infestation, and adds further to our knowledge on insect egg-induced transcriptomic changes in plants. The sequences identified in our comparative analysis give many hints about novel defense mechanisms directed towards eggs.

Micro-scale anaerobic digestion of point source components of organic fraction of municipal solid waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chanakya, H.N.; Sharma, Isha; Ramachandra, T.V.

The fermentation characteristics of six specific types of the organic fraction of municipal solid waste (OFMSW) were examined, with an emphasis on properties that are needed when designing plug-flow type anaerobic bioreactors. More specifically, the decomposition patterns of a vegetable (cabbage), fruits (banana and citrus peels), fresh leaf litter of bamboo and teak leaves, and paper (newsprint) waste streams as feedstocks were studied. Individual OFMSW components were placed into nylon mesh bags and subjected to various fermentation periods (solids retention time, SRT) within the inlet of a functioning plug-flow biogas fermentor. These were removed at periodic intervals, and their compositionmore » was analyzed to monitor decomposition rates and changes in chemical composition. Components like cabbage waste, banana peels, and orange peels fermented rapidly both in a plug-flow biogas reactor (PFBR) as well as under a biological methane potential (BMP) assay, while other OFMSW components (leaf litter from bamboo and teak leaves and newsprint) fermented slowly with poor process stability and moderate biodegradation. For fruit and vegetable wastes (FVW), a rapid and efficient removal of pectins is the main cause of rapid disintegration of these feedstocks, which left behind very little compost forming residues (2-5%). Teak and bamboo leaves and newsprint decomposed only to 25-50% in 30 d. These results confirm the potential for volatile fatty acids accumulation in a PFBR's inlet and suggest a modification of the inlet zone or operation of a PFBR with the above feedstocks.« less

Micro-scale anaerobic digestion of point source components of organic fraction of municipal solid waste.

PubMed

Chanakya, H N; Sharma, Isha; Ramachandra, T V

2009-04-01

The fermentation characteristics of six specific types of the organic fraction of municipal solid waste (OFMSW) were examined, with an emphasis on properties that are needed when designing plug-flow type anaerobic bioreactors. More specifically, the decomposition patterns of a vegetable (cabbage), fruits (banana and citrus peels), fresh leaf litter of bamboo and teak leaves, and paper (newsprint) waste streams as feedstocks were studied. Individual OFMSW components were placed into nylon mesh bags and subjected to various fermentation periods (solids retention time, SRT) within the inlet of a functioning plug-flow biogas fermentor. These were removed at periodic intervals, and their composition was analyzed to monitor decomposition rates and changes in chemical composition. Components like cabbage waste, banana peels, and orange peels fermented rapidly both in a plug-flow biogas reactor (PFBR) as well as under a biological methane potential (BMP) assay, while other OFMSW components (leaf litter from bamboo and teak leaves and newsprint) fermented slowly with poor process stability and moderate biodegradation. For fruit and vegetable wastes (FVW), a rapid and efficient removal of pectins is the main cause of rapid disintegration of these feedstocks, which left behind very little compost forming residues (2-5%). Teak and bamboo leaves and newsprint decomposed only to 25-50% in 30d. These results confirm the potential for volatile fatty acids accumulation in a PFBR's inlet and suggest a modification of the inlet zone or operation of a PFBR with the above feedstocks.

Insecticidal toxicities of carvacrol and thymol derived from Thymus vulgaris Lin. against Pochazia shantungensis Chou & Lu., newly recorded pest

NASA Astrophysics Data System (ADS)

Park, Jun-Hwan; Jeon, Ye-Jin; Lee, Chi-Hoon; Chung, Namhyun; Lee, Hoi-Seon

2017-01-01

The insecticidal toxicities of five essential oils against Pochazia shantungensis adults and nymphs, newly recorded pests, were evaluated. The LC50 values of Thymus vulgaris, Ruta graveolens, Citrus aurantium, Leptospermum petersonii and Achillea millefolium oils were recorded as 57.48, 84.44, 92.58, 113.26 and 125.78 mg/L, respectively, against P. shantungensis nymphs using the leaf dipping bioassay, and 75.80, 109.86, 113.26, 145.06 and 153.74 mg/L, respectively, against P. shantungensis adults using the spray bioassay method. Regarding volatile components identified in T. vulgaris oil, the LC50 values of carvacrol and thymol using the leaf dipping bioassay against P. shantungensis nymphs were 56.74 and 28.52 mg/L, respectively. The insecticidal action of T. vulgaris oil against P. shantungensis could be attributed to carvacrol and thymol. Based on the structure-toxicity relationship between thymol analogs and insecticidal toxicities against P. shantungensis nymphs similar to the LC50 values against P. shantungensis adults, the LC50 values of thymol, carvacrol, citral, 2-isopropylphenol, 3-isopropylphenol, and 4-isopropylphenol were 28.52, 56.74 and 89.12, 71.41, 82.49, and 111.28 mg/L, respectively. These results indicate that the insecticidal mode of action of thymol analogs may be largely attributed to the methyl functional group. Thymol analogues have promising potential as first-choice insecticides against P. shantungensis adults and nymphs.

Distribution Characteristics of Eggs and Neonate Larvae of Codling Moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae)

PubMed Central

Wearing, Christopher H.

2016-01-01

Literature is reviewed on the spatial distribution of the eggs and neonate larvae of codling moth on apple trees in relation to research conducted in Nelson, New Zealand. At Nelson, oviposition increased with height and was greater in the north and east of the trees and in those with greater fruit load in some seasons, which matches published reports. All publications and the research recorded high percentages of eggs laid singly within 10–15 cm of the fruit, with most eggs on leaves even within fruit clusters; oviposition on fruit clusters of different sizes was nonrandom because more eggs were laid on those with more fruit, but the aggregation of both per cluster and within clusters was even greater than that caused by the fruit number alone. Oviposition at random with respect to the fruit occurred only at very low population density. The choice of oviposition site between fruit and the adaxial leaf surface and abaxial leaf surface (AbLS) was variable and cultivar related. Cultivars on which eggs predominated on the AbLS were less frequent and characterized by low trichome density. In the literature, neonate larvae from eggs on the AbLS suffered greater mortality, as did those in Nelson that hatched more distant from the fruit. This review discusses the interaction between these distribution characteristics and species-specific host–plant volatiles, egg adhesion to plant surfaces, oviposition deterrents, predation, and their relevance to pest management. PMID:27429560

Allelopathic Monoterpenes Interfere with Arabidopsis thaliana Cuticular Waxes and Enhance Transpiration

PubMed Central

Kussmann, Petra; Knop, Mona; Kriegs, Bettina; Gresens, Frank; Eichert, Thomas; Ulbrich, Andreas; Marx, Friedhelm; Fabricius, Heinz; Goldbach, Heiner; Noga, Georg

2007-01-01

Exposure to the allelopathic monoterpenes camphor (100 mg/10 L) and menthol (50 mg/10 L) for 24 h enhanced transpiration of Arabidopsis thaliana fully developed rosette leaves similar to de-waxing. As ascertained by ESEM analyses the leaf surfaces were spotted with platelet like structures which seem to be partly mixed with the lipophilic epicuticular layers. The structures are supposed to contain the condensed monoterpenes, which could be identified by GC. Long term exposure (more than 48 h) to 100 mg/50 mg killed the plants by desiccation, a 24 h exposure caused necrotic spots that became visible one to two days after the treatment. Examinations of the stomatal apertures indicated that monoterpenes induced stomatal opening followed by extreme swelling and a final break down of the protoplasts. Exposure of Arabidopsis thaliana to volatiles of Mentha piperita, Lavandula latifolia and Artemisia camphorata resulted in a dramatic increase of the stomata aperture but swelling of the protoplasts was less exhibited. In contrast to de-waxing, expression of the fatty acid condensing enzyme encoding CER6 gene and de novo synthesis of CER6 protein was not induced after 24 h of exposure to the monoterpenes. The aim of the study was to demonstrate that the lipophilic layers of the leaf surface and the stomata are primary targets of monoterpene allelopathic attack. Enhanced transpiration results from a combination of affected lipophilic wax layers and a disturbed stomata function. PMID:19516993

Estimation of biogenic volatile organic compound (BVOC) emissions from the terrestrial ecosystem in China using real-time remote sensing data

NASA Astrophysics Data System (ADS)

Li, M.; Huang, X.; Li, J.; Song, Y.

2012-03-01

Because of the high emission rate and reactivity, biogenic volatile organic compounds (BVOCs) play a significant role in the terrestrial ecosystems, human health, secondary pollution, global climate change and the global carbon cycle. Past estimations of BVOC emissions in China were based on outdated algorithms and coarsely resolved meteorological data, and there have been significant inconsistences between the land surface parameters of dynamic models and those of BVOC estimation models, leading to large inaccuracies in the estimated results. To refine BVOC emission estimations for China and to further explore the role of BVOCs in the atmosphere, we used the latest algorithms of MEGAN (Model of Emissions of Gases and Aerosols from Nature), with MM5 (the Fifth-Generation Mesoscale Model) providing highly resolved meteorological data, to estimate the biogenic emissions of isoprene (C5H8) and seven monoterpene species (C10H16) in 2006. Real-time MODIS (Moderate Resolution Imaging Spectroradiometer) data were introduced to update the land surface parameters and to improve the simulation performance of MM5, and to determine the influence of leaf area index (LAI) and leaf age deviation from standard conditions. In this study, the annual BVOC emissions for the whole country totaled 12.97 Tg C, a relevant value compared with past studies. Therein, the most important individual contributor was isoprene (9.36 Tg C yr-1), followed by α-pinene (1.24 Tg C yr-1) and β-pinene (0.84 Tg C yr-1). Due to the considerable regional disparity in plant distributions and meteorological conditions across China, BVOC emissions presented significant spatial and temporal variations. Spatially, isoprene emission was concentrated in South China, which is covered by large areas of broadleaf forests and shrubs. While Southeast China was the top-ranking contributor of monoterpenes, in which the dominant vegetation genera consist of evergreen coniferous forests. Temporally, BVOC emissions primarily occurred in July and August, with daily emissions peaking at about 13:00∼14:00 h (Beijing Time, BJT). In this study, we present an improved estimation of BVOC emissions, which provides important information for further exploration of the role of BVOCs in atmospheric processes.

Antimicrobial efficacy of Syzygium antisepticum plant extract against Staphylococcus aureus and methicillin-resistant S. aureus and its application potential with cooked chicken.

PubMed

Yuan, Wenqian; Yuk, Hyun-Gyun

2018-06-01

For the past decades, there has been a growing demand for natural antimicrobials in the food industry. Plant extracts have attracted strong research interests due to their wide-spectrum antimicrobial activities, but only a limited number have been investigated thoroughly. The present study aimed at identifying a novel anti-staphylococcal plant extract, to validate its activity in a food model, and to investigate on its composition and antimicrobial mechanism. Four plant extracts were evaluated against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) in vitro, with Syzygium antisepticum leaf extract showing the strongest antimicrobial activity (MIC = 0.125 mg/mL). Relatively high total phenolic content (276.3 mg GAE/g extract) and antioxidant activities (90.2-138.0 mg TE/g extract) were measured in S. antisepticum extract. Food validation study revealed that higher extract concentration (32 mg/mL) was able to inhibit or reduce staphylococcal growth in cooked chicken, but caused color change on meat surface. By GC-MS, β-caryophyllene (12.76 area%) was identified as the dominant volatile compound in extract. Both crude extract and pure β-caryophyllene induced membrane damages in S. aureus. These results suggested good anti-staphylococcal properties of S. antisepticum plant extract, identified its major volatile composition and its membrane-damaging antimicrobial mechanism. Copyright © 2017 Elsevier Ltd. All rights reserved.

Odor, Not Performance, Dictates Bemisia tabaci's Selection between Healthy and Virus Infected Plants

PubMed Central

Chen, Gong; Su, Qi; Shi, Xiaobin; Liu, Xin; Peng, Zhengke; Zheng, Huixin; Xie, Wen; Xu, Baoyun; Wang, Shaoli; Wu, Qingjun; Zhou, Xuguo; Zhang, Youjun

2017-01-01

Although, insect herbivores are generally thought to select hosts that favor the fitness of their progeny, this “mother-knows-best” hypothesis may be challenged by the presence of a plant virus. Our previous study showed that the whitefly, Bemisia tabaci, the obligate vector for transmitting Tomato yellow leaf curl virus (TYLCV), preferred to settle and oviposit on TYLCV-infected rather than healthy host plant, Datura stramonium. The performances of B. tabaci larvae and adults were indeed improved on virus-infected D. stramonium, which is consistent with “mother-knows-best” hypothesis. In this study, B. tabaci Q displayed the same preference to settle and oviposit on Tomato spotted wilt virus (TSWV)-infected host plants, D. stramonium and Capsicum annuum, respectively. As a non-vector of TSWV, however, insect performance was impaired since adult body size, longevity, survival, and fecundity were reduced in TSWV infected D. stramonium. This appears to be an odor-mediated behavior, as plant volatile profiles are modified by viral infection. Infected plants have reduced quantities of o-xylene and α-pinene, and increased levels of phenol and 2-ethyl-1-hexanol in their headspace. Subsequent behavior experiments showed that o-xylene and α-pinene are repellant, while phenol and 2-ethyl-1-hexanol are attractive. This indicates that the preference of B. tabaci for virus-infected plants is modulated by the dynamic changes in the volatile profiles rather than the subsequent performances on virus-infected plants. PMID:28360861

Priming of cowpea volatile emissions with defense inducers enhances the plant's attractiveness to parasitoids when attacked by caterpillars.

PubMed

Sobhy, Islam S; Bruce, Toby Ja; Turlings, Ted Cj

2018-04-01

The manipulation of herbivore-induced volatile organic compounds (HI-VOCs) via the application of the inducers benzo(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester (BTH) and laminarin (β-1,3-glucan) is known to enhance the attractiveness of caterpillar-damaged cotton and maize plants to parasitoids. To test if this is also the case for legumes, we treated cowpea (Vigna unguiculata var. unguiculata) with these inducers and studied the effects on HI-VOC emissions and the attraction of three generalist endoparasitoids. After the inducers had been applied and the plants subjected to either real or mimicked herbivory by Spodoptera littoralis caterpillars, females of the parasitoids Campoletis sonorensis and Microplitis rufiventris showed a strong preference for BTH-treated plants, whereas Cotesia females were strongly attracted to both BTH- and laminarin-treated plants with real or mimicked herbivory. Treated plants emitted more of certain HI-VOCs, but considerably less indole and linalool and less of several sesquiterpenes. Multivariate data analysis revealed that enhanced wasp attraction after treatment was correlated with high relative concentrations of nonanal, α-pinene, (E)-β-ocimene and (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), and with low relative concentrations of indole, (S)-linalool and (E)-β-farnesene. Inducer treatments had no significant effect on leaf consumption by the caterpillars. Our findings confirm that treating cowpea plants with inducers can enhance their attractiveness to biological control agents. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Expression profiling of various genes during the fruit development and ripening of mango.

PubMed

Pandit, Sagar S; Kulkarni, Ram S; Giri, Ashok P; Köllner, Tobias G; Degenhardt, Jörg; Gershenzon, Jonathan; Gupta, Vidya S

2010-06-01

Mango (Mangifera indica L. cv. Alphonso) development and ripening are the programmed processes; conventional indices and volatile markers help to determine agronomically important stages of fruit life (fruit-setting, harvesting maturity and ripening climacteric). However, more and precise markers are required to understand this programming; apparently, fruit's transcriptome can be a good source of such markers. Therefore, we isolated 18 genes related to the physiology and biochemistry of the fruit and profiled their expression in developing and ripening fruits, flowers and leaves of mango using relative quantitation PCR. In most of the tissues, genes related to primary metabolism, abiotic stress, ethylene response and protein turnover showed high expression as compared to that of the genes related to flavor production. Metallothionin and/or ethylene-response transcription factor showed highest level of transcript abundance in all the tissues. Expressions of mono- and sesquiterpene synthases and 14-3-3 lowered during ripening; whereas, that of lipoxygenase, ethylene-response factor and ubiquitin-protein ligase increased during ripening. Based on these expression profiles, flower showed better positive correlation with developing and ripening fruits than leaf. Most of the genes showed their least expression on the second day of harvest, suggesting that harvesting signals significantly affect the fruit metabolism. Important stages in the fruit life were clearly indicated by the significant changes in the expression levels of various genes. These indications complemented those from the previous analyses of fruit development, ripening and volatile emission, revealing the harmony between physiological, biochemical and molecular activities of the fruit.

Tracing the link between plant volatile organic compound emissions and CO2 fluxes and by stable isotopes

NASA Astrophysics Data System (ADS)

Werner, Christiane; Wegener, Frederik; Jardine, Kolby

2015-04-01

The vegetation exerts a large influence on the atmosphere through the emission of volatile organic compounds (VOCs) and the emission and uptake of the greenhouse gas CO2. Despite the enormous importance, processes controlling plant carbon allocation into primary and secondary metabolism, such as photosynthetic carbon uptake, respiratory CO2 emission and VOC synthesis, remains unclear. Moreover, vegetation-atmosphere CO2 exchange is associated with a large isotopic imprint due to photosynthetic carbon isotope discrimination and 13C-fractionation during respiratory CO2 release1. The latter has been proposed to be related to carbon partitioning in the metabolic branching points of the respiratory pathways and secondary metabolism, which are linked via a number of interfaces including the central metabolite pyruvate. Notably, it is a known substrate in a large array of secondary pathways leading to the biosynthesis of many volatile organic compounds (VOCs), such as volatile isoprenoids, oxygenated VOCs, aromatics, fatty acid oxidation products, which can be emitted by plants. Here we investigate the linkage between VOC emissions, CO2 fluxes and associated isotope effects based on simultaneous real-time measurements of stable carbon isotope composition of branch respired CO2 (CRDS) and VOC fluxes (PTR-MS). We utilized positionally specific 13C-labeled pyruvate branch feeding experiments in the mediterranean shrub (Halimium halimifolium) to trace the partitioning of C1, C2, and C3 carbon atoms of pyruvate into VOCs versus CO2 emissions in the light and in the dark. In the light, we found high emission rates of a large array of VOC including volatile isoprenoids, oxygenated VOCs, green leaf volatiles, aromatics, sulfides, and nitrogen containing VOCs. These observations suggest that in the light, H. halimifolium dedicates a high carbon flux through secondary biosynthetic pathways including the pyruvate dehydrogenase bypass, mevalonic acid, MEP/DOXP, shikimic acid, and fatty acid pathways. Moreover, we found that high VOC emissions were closely related to 13CO2 decarboxylation from pyruvate-1-13C in the light, while mitochondrial respiration mas markedly down-regulated. Moreover, we found that in the dark, VOC emissions dramatically declined while respiration was stimulated with 13CO2 emissions under pyruvate-1-13C exceeding those under pyruvate-2-13C and pyruvate-2,3-13C during light-dark transitions. Our observations suggest VOC emissions are associated with significant pyruvate C1 decarboxylation. Moreover, the data suggests that light fundamentally controls the partitioning of assimilated carbon in leaves by regulating the competition for pyruvate between secondary biosynthetic reactions (e.g. VOC production) and mitochondrial respiration. Our investigation provides novel tool to better understand the mechanistic links between primary and secondary carbon metabolism in plants with important implications for a better understanding biosphere-atmosphere exchange of CO2 and VOCs. References 1. Werner C. & Gessler A. (2011) Diel variations in the carbon isotope composition of respired CO2 and associated carbon sources: a review of dynamics and mechanisms. Biogeosciences 8, 2437-2459 2. Jardine K, Wegener F, Abrell L, vonHaren J, Werner C (2014) Phytogenic biosynthesis and emission of methyl acetate. PCE 37, 414-424.

Antimicrobial activities of essential oil and hexane extract of Florence fennel [Foeniculum vulgare var. azoricum (Mill.) Thell.] against foodborne microorganisms.

PubMed

Cetin, Bülent; Ozer, Hakan; Cakir, Ahmet; Polat, Taşkin; Dursun, Atilla; Mete, Ebru; Oztürk, Erdoğan; Ekinci, Melek

2010-02-01

The objective of this study was to determine the chemical compositions of the essential oil and hexane extract isolated from the inflorescence, leaf stems, and aerial parts of Florence fennel and the antimicrobial activities of the essential oil, hexane extract, and their major component, anethole, against a large variety of foodborne microorganisms. Gas chromatography and gas chromatography-mass spectrometry analysis showed that the essential oils obtained from inflorescence, leaf stems, and whole aerial parts contained (E)-anethole (59.28-71.69%), limonene (8.30-10.73%), apiole (trace to 9.23%), beta-fenchyl acetate (3.02-4.80%), and perillene (2.16-3.29%) as the main components. Likewise, the hexane extract of the plant sample exhibited a similar chemical composition, and it contained (E)-anethole (53.00%), limonene (27.16%), gamma-terpinene (4.09%), and perillene (3.78%). However, the hexane extract also contained less volatile components such as n-hexadecanoic acid (1.62%), methyl palmitate (1.17%), and linoleic acid (1.15%). The in vitro antimicrobial assays showed that the essential oil, anethole, and hexane extract were effective against most of the foodborne pathogenic, saprophytic, probiotic, and mycotoxigenic microorganisms tested. The results of the present study revealed that (E)-anethole, the main component of Florence fennel essential oil, is responsible for the antimicrobial activity and that the essential oils as well as the hexane extract can be used as a food preservative. This study is the first report showing the antimicrobial activities of essential oil and hexane extract of Florence fennel against probiotic bacteria.

Comparative biochemical analysis during the anaerobic digestion of lignocellulosic biomass from six morphological parts of Williams Cavendish banana (Triploid Musa AAA group) plants.

PubMed

Kamdem, Irénée; Hiligsmann, Serge; Vanderghem, Caroline; Bilik, Igor; Paquot, Michel; Thonart, Philippe

2013-12-01

We studied banana lignocellulosic biomass (BALICEBIOM) that is abandoned after fruit harvesting, and assessed its biochemical methane potential, because of its potential as an energy source. We monitored biogas production from six morphological parts (MPs) of the "Williams Cavendish" banana cultivar using a modified operating procedure (KOP) using KOH. Volatile fatty acid (VFA) production was measured using high performance liquid chromatography. The bulbs, leaf sheaths, petioles-midribs, leaf blades, rachis stems, and floral stalks gave total biogas production of 256, 205, 198, 126, 253, and 221 ml g⁻¹ dry matter, respectively, and total biomethane production of 150, 141, 127, 98, 162, and 144 ml g⁻¹, respectively. The biogas production rates and yields depended on the biochemical composition of the BALICEBIOM and the ability of anaerobic microbes to access fermentable substrates. There were no significant differences between the biogas analysis results produced using KOP and gas chromatography. Acetate was the major VFA in all the MP sample culture media. The bioconversion yields for each MP were below 50 %, showing that these substrates were not fully biodegraded after 188 days. The estimated electricity that could be produced from biogas combustion after fermenting all of the BALICEBIOM produced annually by the Cameroon Development Corporation-Del Monte plantations for 188 days is approximately 10.5 × 10⁶ kW h (which would be worth 0.80-1.58 million euros in the current market). This bioenergy could serve the requirements of about 42,000 people in the region, although CH₄ productivity could be improved.

Attractiveness of fruit and flower odorants detected by olfactory receptor neurons in the fruit chafer Pachnoda marginata.

PubMed

Larsson, Mattias C; Stensmyr, Marcus C; Bice, Shannon B; Hansson, Bill S

2003-05-01

We studied the attraction of the African fruit chafer Pachnoda marginata Drury (Coleoptera: Scarabaeidae) to banana and 34 synthetic plant compounds previously shown to be detected by P. marginata olfactory receptor neurons. The behavioral studies were carried out in a two-choice olfactometer, where the attraction of beetles to lures and controls was monitored in 30-min intervals during whole days. Monitoring of the attraction over time gave additional information when comparing relative attractiveness of different compounds. Seventeen of the test compounds, primarily phenylic compounds, fruit esters, isovaleric acid, acetoin, and some floral or fruit terpenes, were attractive to P. marginata. Compounds showing no attractiveness included green leaf volatiles, lactones. and several alcohols, but also phenylic compounds and esters. One case of blend synergism was demonstrated, as well as some examples of sexual dimorphism in attraction. The significance of certain compounds and receptor neurons for olfactory-guided behavior of phytophagous scarabs is discussed.

Rust and Thinning Management Effect on Cup Quality and Plant Performance for Two Cultivars of Coffea arabica L.

PubMed

Echeverria-Beirute, Fabian; Murray, Seth C; Klein, Patricia; Kerth, Chris; Miller, Rhonda; Bertrand, Benoit

2018-05-30

Beverage quality is a complex attribute of coffee ( Coffea arabica L.). Genotype (G), environment (E), management (M), postharvest processing, and roasting are all involved. However, little is known about how G × M interactions influence beverage quality. We investigated how yield and coffee leaf rust (CLR) disease (caused by Hemileia vastatrix Berk. et Br.) management affect cup quality and plant performance, in two coffee cultivars. Sensory and chemical analyses revealed that 10 of 70 attributes and 18 of 154 chemical volatile compounds were significantly affected by G and M. Remarkably, acetaminophen was found for the first time in roasted coffee and in higher concentrations under more stressful conditions. A principal component analysis described 87% of the variation in quality and plant overall performance. This study is a first step in understanding the complexity of the physiological, metabolic, and molecular changes in coffee production, which will be useful for the improvement of coffee cultivars.

Protected by fumigants: beetle perfumes in antimicrobial defense.

PubMed

Gross, Jürgen; Schumacher, Kerstin; Schmidtberg, Henrike; Vilcinskas, Andreas

2008-02-01

Beetles share with other eukaryotes an innate immune system that mediates endogenous defense against pathogens. In addition, larvae of some taxa produce fluid exocrine secretions that contain antimicrobial compounds. In this paper, we provide evidence that larvae of the brassy willow leaf beetle Phratora vitellinae constitutively release volatile glandular secretions that combat pathogens in their microenvironment. We identified salicylaldehyde as the major component of their enveloping perfume cloud, which is emitted by furrow-shaped openings of larval glandular reservoirs and which inhibits in vitro the growth of the bacterial entomopathogen Bacillus thuringiensis. The suggested role of salicylaldehyde as a fumigant in exogenous antimicrobial defense was confirmed in vivo by its removal from glandular reservoirs. This resulted in an enhanced susceptibility of the larvae to infection with the fungal entomopathogens Beauveria bassiana and Metarhizium anisopliae. Consequently, we established the hypothesis that antimicrobial defense in beetles can be expanded beyond innate immunity to include external disinfection of their microenvironment, and we report for the first time the contribution of fumigants to antimicrobial defense in animals.

Preliminary study on biomarkers for the fungal resistance in Vitis vinifera leaves.

PubMed

Batovska, Daniela Ilieva; Todorova, Iva Todorova; Nedelcheva, Daniela Valentinova; Parushev, Stoyan Parushev; Atanassov, Atanas Ivanov; Hvarleva, Tzvetanka Dimitrova; Djakova, Galina Jordanova; Bankova, Vassya Stefanova; Popov, Simeon Simeonov

2008-05-26

We examined the leaf chemical composition of six seedlings obtained by self-pollination of the Bulgarian wine-making variety Storgozia as well as the cultivar Bouquet, which is the susceptible parent of Storgozia. The chemical composition was investigated in the framework of a program for identification of metabolites associated with disease resistance in grape-vine. Acetone, dichloromethane and butanol extracts, as well as volatiles obtained from fresh material were analyzed by GC/MS. Based on the correlations of the GC/MS data and estimated resistance of the leaves towards the etiological agents of powdery mildew, downy mildew and botrytis as biomarkers for the fungal resistance, we proposed 16 individual metabolites--alpha- and gamma-tocopherol, squalene, alpha-amyrine, stigmasta-3,5-diene-7-one, hexahydrofarnesyl acetone, glycolic acid, 3-hydroxybutanoic acid, 3-hydroxycaproic acid, malic acid, tartaric acid, erythronic acid, arabinoic acid, monoethyl phosphate, undecyl laurate and isopropyl myristate. The obtained correlations were confirmed by cluster analysis.

Volatile organic compounds sources and sinks in a wheat canopy. Analysis based on combined eddy-covariance fluxes, in-canopy profiles and chamber measurements with a PTR-TOF-Qi-MS

NASA Astrophysics Data System (ADS)

Loubet, Benjamin; Gonzaga, Lais; Buysse, Pauline; Ciuraru, Raluca; Lafouge, Florence; Decuq, Céline; Zurfluh, Olivier; Fortineau, Alain; Fanucci, Olivier; Sarda-Esteve, Roland; Zannoni, Nora; Truong, Francois; Boissard, Christophe; Gros, Valérie

2017-04-01

Volatile organic compounds (VOC) are essential drivers of atmospheric chemistry. Many VOCs are emitted from and deposited to ecosystems. While forests and grasslands have already been substantially studied, exchanges of VOCs with crops are less known, although these ecosystems represent more than 50% of the surface in France. In this study, we analyze sources and sinks of VOCs in a wheat field (at the ICOS FR-GRI site near Paris) at anthesis based on measurements of fluxes, concentration profiles and branch chambers. The VOCs were measured using a PTR-TOF-Qi-MS (where Qi stands for Quad Ion guide). Air was successively sampled through lines located at different heights within and above the canopy, of which one was used for Eddy Covariance and located near a sonic anemometer. Additional measurements included the standard ICOS meteorological data as well as leaf area index profiles and photosynthesis curves at several heights in the canopy. We report fluxes and profiles for more than 500 VOCs. The deposition velocities of depositing compounds are compared to the maximum exchange velocity and the ozone deposition velocity. The sources and sinks location and magnitude are evaluated by inverse Lagrangian modelling assuming no reaction and simple reaction schemes in the canopy. The sources and sinks of VOC in the canopy are interpreted in terms crop phenology and the potential for reaction with ozone and NOx is evaluated. This study takes place in the ADEME CORTEA COV3ER French project (http://www6.inra.fr/cov3er).

Biochemical crypsis in the avoidance of natural enemies by an insect herbivore

PubMed Central

De Moraes, Consuelo M.; Mescher, Mark C.

2004-01-01

Plant-herbivore interactions provide well studied examples of coevolution, but little is known about how such interactions are influenced by the third trophic level. Here we show that larvae of the specialized lepidopteran herbivore Heliothis subflexa reduce their vulnerability to natural enemies through adaptation to a remarkable and previously unknown feature of their host plant, Physalis angulata: The fruits of this plant lack linolenic acid (LA), which is required for the development of most insects. By overcoming this nutritional deficiency, H. subflexa larvae achieve numerous advantages. First, they gain near-exclusive access to a food resource: we demonstrate that closely related Heliothis virescens larvae cannot develop on P. angulata fruit unless the fruit are treated with LA. Second, they reduce their vulnerability to enemies: LA is a key component of volicitin, an elicitor of plant-volatile-signaling defenses. We demonstrate that volicitin is absent in the oral secretions of fruit-feeding caterpillars, that the volatile profiles of plants induced by fruit feeding differ from those induced by leaf feeding or by feeding on LA-treated fruit, and that the former are far less attractive to female Cardiochiles nigriceps parasitoids. Finally, they render themselves nutritionally unsuitable as hosts for enemies that require LA for their own development: we show that C. nigriceps larvae fail to develop within the bodies of fruit-feeding caterpillars but do develop in caterpillars feeding on LA-treated fruit. Thus, H. subflexa larvae not only overcome a serious dietary deficiency but also reduce their vulnerability to natural enemies through a form of “biochemical crypsis.” PMID:15184664

Biochemical crypsis in the avoidance of natural enemies by an insect herbivore.

PubMed

De Moraes, Consuelo M; Mescher, Mark C

2004-06-15

Plant-herbivore interactions provide well studied examples of coevolution, but little is known about how such interactions are influenced by the third trophic level. Here we show that larvae of the specialized lepidopteran herbivore Heliothis subflexa reduce their vulnerability to natural enemies through adaptation to a remarkable and previously unknown feature of their host plant, Physalis angulata: The fruits of this plant lack linolenic acid (LA), which is required for the development of most insects. By overcoming this nutritional deficiency, H. subflexa larvae achieve numerous advantages. First, they gain near-exclusive access to a food resource: we demonstrate that closely related Heliothis virescens larvae cannot develop on P. angulata fruit unless the fruit are treated with LA. Second, they reduce their vulnerability to enemies: LA is a key component of volicitin, an elicitor of plant-volatile-signaling defenses. We demonstrate that volicitin is absent in the oral secretions of fruit-feeding caterpillars, that the volatile profiles of plants induced by fruit feeding differ from those induced by leaf feeding or by feeding on LA-treated fruit, and that the former are far less attractive to female Cardiochiles nigriceps parasitoids. Finally, they render themselves nutritionally unsuitable as hosts for enemies that require LA for their own development: we show that C. nigriceps larvae fail to develop within the bodies of fruit-feeding caterpillars but do develop in caterpillars feeding on LA-treated fruit. Thus, H. subflexa larvae not only overcome a serious dietary deficiency but also reduce their vulnerability to natural enemies through a form of "biochemical crypsis."

A new plant chamber facility PLUS coupled to the atmospheric simulation chamber SAPHIR

NASA Astrophysics Data System (ADS)

Hohaus, T.; Kuhn, U.; Andres, S.; Kaminski, M.; Rohrer, F.; Tillmann, R.; Wahner, A.; Wegener, R.; Yu, Z.; Kiendler-Scharr, A.

2015-11-01

A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been build and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees are mixed with synthetic air and are transferred to the SAPHIR chamber where the atmospheric chemistry and the impact of biogenic volatile organic compounds (BVOC) can be studied in detail. In PLUS all important enviromental parameters (e.g. temperature, PAR, soil RH etc.) are well-controlled. The gas exchange volume of 9.32 m3 which encloses the stem and the leafes of the plants is constructed such that gases are exposed to FEP Teflon film and other Teflon surfaces only to minimize any potential losses of BVOCs in the chamber. Solar radiation is simulated using 15 LED panels which have an emission strength up to 800 μmol m-2 s-1. Results of the initial characterization experiments are presented in detail. Background concentrations, mixing inside the gas exchange volume, and transfer rate of volatile organic compounds (VOC) through PLUS under different humidity conditions are explored. Typical plant characteristics such as light and temperature dependent BVOC emissions are studied using six Quercus Ilex trees and compared to previous studies. Results of an initial ozonolysis experiment of BVOC emissions from Quercus Ilex at typical atmospheric concentrations inside SAPHIR are presented to demonstrate a typical experimental set up and the utility of the newly added plant chamber.

Allelopathic assessment of selected common weeds in Malaysia

NASA Astrophysics Data System (ADS)

Nurul Ain, M. B.; Nornasuha, Y.; Ismail, B. S.

2016-11-01

A laboratory study was conducted to evaluate the allelopathic potential of eight common weed species in Malaysia, namely, Ageratum conyzoides, Tridax procumbens, Cyperus iria, Fimbristylis miliacea, Eleusine indica, Imperata cylindrica, Lygodium flexuosum and Nephrolepis biserrata of different morphological characteristics (broadleaves, sedges, grasses and ferns). The allelopathic study of these weeds was carried out by testing the leaf litter leachate through the Sandwich method and the volatile compounds of these weeds through the Dish pack method with three replicates for each donor species. The results obtained from both methods were statistically analyzed and the means had converted to percentage growth inhibition to determine the inhibition pattern on the radicle and hypocotyl growth of lettuce seedlings. Among the eight weed species tested, Ageratum conyzoides showed the strongest growth inhibition on lettuce radicle elongation (86%) in the sandwich bioassay compared to the control, followed by Tridax procumbens (71%), which both species being broadleaves weeds. In the dish pack bioassay Lygodium flexuosum (fern) demonstrated maximum inhibition on the growth the radicle and hypocotyl for each different distance from the source well. On the other hand, two weed species exhibited enhanced on the growth radicle and hypocotyl when compared to that of the control in dish pack bioassay. Nephrolepis biserrata and Fimbristylis miliacea were the species that showed the highest growth stimulatory effect. The results presented can be utilized as benchmark information for further research on the elucidation of leachates and volatile chemicals involved in allelopathy in nature. The information can also be helpful in the development of new bioactive chemicals from natural products in weed control strategies.

The Gastropod Menace: Slugs on Brassica Plants Affect Caterpillar Survival through Consumption and Interference with Parasitoid Attraction.

PubMed

Desurmont, Gaylord A; Zemanova, Miriam A; Turlings, Ted C J

2016-03-01

Terrestrial molluscs and insect herbivores play a major role as plant consumers in a number of ecosystems, but their direct and indirect interactions have hardly been explored. The omnivorous nature of slugs makes them potential disrupters of predator-prey relationships, as a direct threat to small insects and through indirect, plant-mediated effects. Here, we examined the effects of the presence of two species of slugs, Arion rufus (native) and A. vulgaris (invasive) on the survivorship of young Pieris brassicae caterpillars when feeding on Brassica rapa plants, and on plant attractiveness to the main natural enemy of P. brassicae, the parasitoid Cotesia glomerata. In two separate predation experiments, caterpillar mortality was significantly higher on plants co-infested with A. rufus or A. vulgaris. Moreover, caterpillar mortality correlated positively with slug mass and leaf consumption by A. vulgaris. At the third trophic level, plants infested with slugs and plants co-infested with slugs and caterpillars were far less attractive to parasitoids than plants damaged by caterpillars only, independently of slug species. Chemical analyses confirmed that volatile emissions, which provide foraging cues for parasitoids, were strongly reduced in co-infested plants. Our study shows that the presence of slugs has the potential to affect insect populations, directly via consumptive effects, and indirectly via changes in plant volatiles that result in a reduced attraction of natural enemies. The fitness cost for P. brassicae imposed by increased mortality in presence of slugs may be counterbalanced by the benefit of escaping its parasitoids.

Isolation of intact sub-dermal secretory cavities from Eucalyptus

PubMed Central

2010-01-01

Background The biosynthesis of plant natural products in sub-dermal secretory cavities is poorly understood at the molecular level, largely due to the difficulty of physically isolating these structures for study. Our aim was to develop a protocol for isolating live and intact sub-dermal secretory cavities, and to do this, we used leaves from three species of Eucalyptus with cavities that are relatively large and rich in essential oils. Results Leaves were digested using a variety of commercially available enzymes. A pectinase from Aspergillus niger was found to allow isolation of intact cavities after a relatively short incubation (12 h), with no visible artifacts from digestion and no loss of cellular integrity or cavity contents. Several measurements indicated the potential of the isolated cavities for further functional studies. First, the cavities were found to consume oxygen at a rate that is comparable to that estimated from leaf respiratory rates. Second, mRNA was extracted from cavities, and it was used to amplify a cDNA fragment with high similarity to that of a monoterpene synthase. Third, the contents of the cavity lumen were extracted, showing an unexpectedly low abundance of volatile essential oils and a sizeable amount of non-volatile material, which is contrary to the widely accepted role of secretory cavities as predominantly essential oil repositories. Conclusions The protocol described herein is likely to be adaptable to a range of Eucalyptus species with sub-dermal secretory cavities, and should find wide application in studies of the developmental and functional biology of these structures, and the biosynthesis of the plant natural products they contain. PMID:20807444

Major Transcriptome Reprogramming Underlies Floral Mimicry Induced by the Rust Fungus Puccinia monoica in Boechera stricta

PubMed Central

Haugen, Riston H.; Saunders, Diane G. O.; Leonelli, Lauriebeth; MacLean, Dan; Hogenhout, Saskia A.; Kamoun, Sophien

2013-01-01

Pucciniamonoica is a spectacular plant parasitic rust fungus that triggers the formation of flower-like structures (pseudoflowers) in its Brassicaceae host plant Boechera stricta . Pseudoflowers mimic in shape, color, nectar and scent co-occurring and unrelated flowers such as buttercups. They act to attract insects thereby aiding spore dispersal and sexual reproduction of the rust fungus. Although much ecological research has been performed on P . monoica -induced pseudoflowers, this system has yet to be investigated at the molecular or genomic level. To date, the molecular alterations underlying the development of pseudoflowers and the genes involved have not been described. To address this, we performed gene expression profiling to reveal 256 plant biological processes that are significantly altered in pseudoflowers. Among these biological processes, plant genes involved in cell fate specification, regulation of transcription, reproduction, floral organ development, anthocyanin (major floral pigments) and terpenoid biosynthesis (major floral volatile compounds) were down-regulated in pseudoflowers. In contrast, plant genes involved in shoot, cotyledon and leaf development, carbohydrate transport, wax biosynthesis, cutin transport and L-phenylalanine metabolism (pathway that results in phenylethanol and phenylacetaldehyde volatile production) were up-regulated. These findings point to an extensive reprogramming of host genes by the rust pathogen to induce floral mimicry. We also highlight 31 differentially regulated plant genes that are enriched in the biological processes mentioned above, and are potentially involved in the formation of pseudoflowers. This work illustrates the complex perturbations induced by rust pathogens in their host plants, and provides a starting point for understanding the molecular mechanisms of pathogen-induced floral mimicry. PMID:24069397

Major transcriptome reprogramming underlies floral mimicry induced by the rust fungus Puccinia monoica in Boechera stricta.

PubMed

Cano, Liliana M; Raffaele, Sylvain; Haugen, Riston H; Saunders, Diane G O; Leonelli, Lauriebeth; MacLean, Dan; Hogenhout, Saskia A; Kamoun, Sophien

2013-01-01

Pucciniamonoica is a spectacular plant parasitic rust fungus that triggers the formation of flower-like structures (pseudoflowers) in its Brassicaceae host plant Boecherastricta. Pseudoflowers mimic in shape, color, nectar and scent co-occurring and unrelated flowers such as buttercups. They act to attract insects thereby aiding spore dispersal and sexual reproduction of the rust fungus. Although much ecological research has been performed on P. monoica-induced pseudoflowers, this system has yet to be investigated at the molecular or genomic level. To date, the molecular alterations underlying the development of pseudoflowers and the genes involved have not been described. To address this, we performed gene expression profiling to reveal 256 plant biological processes that are significantly altered in pseudoflowers. Among these biological processes, plant genes involved in cell fate specification, regulation of transcription, reproduction, floral organ development, anthocyanin (major floral pigments) and terpenoid biosynthesis (major floral volatile compounds) were down-regulated in pseudoflowers. In contrast, plant genes involved in shoot, cotyledon and leaf development, carbohydrate transport, wax biosynthesis, cutin transport and L-phenylalanine metabolism (pathway that results in phenylethanol and phenylacetaldehyde volatile production) were up-regulated. These findings point to an extensive reprogramming of host genes by the rust pathogen to induce floral mimicry. We also highlight 31 differentially regulated plant genes that are enriched in the biological processes mentioned above, and are potentially involved in the formation of pseudoflowers. This work illustrates the complex perturbations induced by rust pathogens in their host plants, and provides a starting point for understanding the molecular mechanisms of pathogen-induced floral mimicry.

Morphology of glandular trichomes of Japanese catnip (Schizonepeta tenuifolia Briquet) and developmental dynamics of their secretory activity.

PubMed

Liu, Chanchan; Srividya, Narayanan; Parrish, Amber N; Yue, Wei; Shan, Mingqiu; Wu, Qinan; Lange, B Markus

2018-06-01

Schizonepeta tenuifolia Briquet, commonly known as Japanese catnip, is used for the treatment of colds, headaches, fevers, and skin rashes in traditional Asian medicine (China, Japan and Korea). The volatile oil and its constituents have various demonstrated biological activities, but there is currently limited information regarding the site of biosynthesis. Light microscopy and scanning electron microscopy indicated the presence of three distinct glandular trichome types which, based on their morphological features, are referred to as peltate, capitate and digitiform glandular trichomes. Laser scanning microscopy and 3D reconstruction demonstrated that terpenoid-producing peltate glandular trichomes contain a disk of twelve secretory cells. The oil of peltate glandular trichomes, collected by laser microdissection or using custom-made micropipettes, was demonstrated to contain (-)-pulegone, (+)-menthone and (+)-limonene as major constituents. Digitiform and capitate glandular trichomes did not contain appreciable levels of terpenoid volatiles. The yield of distilled oil from spikes was significantly (44%) higher than that from leaves, while the composition of oils was very similar. Oils collected directly from leaf peltate glandular trichomes over the course of a growing season contained primarily (-)-pulegone (>80% at 32 days after germination) in young plants, while (+)-menthone began to accumulate later (>75% at 80 days after germination), at the expense of (-)-pulegone (the levels of (+)-limonene remained fairly stable at 3-5%). The current study establishes the morphological and chemical characteristics of glandular trichome types of S. tenuifolia, and also provides the basis for unraveling the biosynthesis of essential oil in this popular medicinal plant. Copyright © 2018 Elsevier Ltd. All rights reserved.

The effect of warming and enhanced ultraviolet radiation on gender-specific emissions of volatile organic compounds from European aspen.

PubMed

Maja, Mengistu M; Kasurinen, Anne; Holopainen, Toini; Julkunen-Tiitto, Riitta; Holopainen, Jarmo K

2016-03-15

Different environmental stress factors often occur together but their combined effects on plant secondary metabolism are seldom considered. We studied the effect of enhanced ultraviolet (UV-B) (31% increase) radiation and temperature (ambient +2 °C) singly and in combination on gender-specific emissions of volatile organic compounds (VOCs) from 2-year-old clones of European aspen (Populus tremula L.). Plants grew in 36 experimental plots (6 replicates for Control, UV-A, UV-B, T, UV-A+T and UV-B+T treatments), in an experimental field. VOCs emitted from shoots were sampled from two (1 male and 1 female) randomly selected saplings (total of 72 saplings), per plot on two sampling occasions (June and July) in 2014. There was a significant UV-B×temperature interaction effect on emission rates of different VOCs. Isoprene emission rate was increased due to warming, but warming also modified VOC responses to both UV-A and UV-B radiation. Thus, UV-A increased isoprene emissions without warming, whereas UV-B increased emissions only in combination with warming. Warming-modified UV-A and UV-B responses were also seen in monoterpenes (MTs), sesquiterpenes (SQTs) and green leaf volatiles (GLVs). MTs showed also a UV × gender interaction effect as females had higher emission rates under UV-A and UV-B than males. UV × gender and T × gender interactions caused significant differences in VOC blend as there was more variation (more GLVs and trans-β-caryophyllene) in VOCs from female saplings compared to male saplings. VOCs from the rhizosphere were also collected from each plot in two exposure seasons, but no significant treatment effects were observed. Our results suggest that simultaneous warming and elevated-UV-radiation increase the emission of VOCs from aspen. Thus the contribution of combined environmental factors on VOC emissions may have a greater impact to the photochemical reactions in the atmosphere compared to the impact of individual factors acting alone. Copyright © 2015 Elsevier B.V. All rights reserved.

Climatic effects of biogenic volatile organic compounds (BVOCs) emissions and associated feedbacks due to vegetation change in the boreal zone

NASA Astrophysics Data System (ADS)

Blichner, Sara Marie; Koren Berntsen, Terje; Stordal, Frode

2017-04-01

As our understanding of the earth system improves, it is becoming increasingly clear that vegetation and ecosystems are not only influenced by the atmosphere, but that changes in these also feed back to the atmosphere and induce changes here. One such feedback involves the emission of biogenic volatile organic compounds (BVOCs) emitted from vegetation. As BVOCs are oxidized, they become less volatile and contribute to aerosol growth and formation in the atmosphere, and can thus change the radiative balance of the atmosphere through both the direct and indirect aerosol effects. The amount and type of BVOCs emitted by vegetation depends on a myriad of variables; temperature, leaf area index (LAI), species, water availability and various types of stress (e.g. insects attacks). They generally increase with higher temperatures and under stress. These factors beg the question of how emissions will change in the future in response to both temperature increase and changes to vegetation patterns and densities. The boreal region is of particular interest because forest cover in general has been thought to have a warming effect due to trees reducing the albedo, especially when snow covers the ground. We investigate feedbacks through BVOC emissions related to the expected northward expansion of boreal forests in response to global warming with a development version of the Norwegian Earth System Model (NorESM). BVOC emissions are computed by the Model of Emissions of Gases and Aerosols from Nature 2.1 (MEGAN2.1) which is incorporated into the Community Land Model v4.5 (CLM4.5). The atmospheric component is CAM5.3-Oslo. We will present preliminary results of effects on clouds and aerosol concentrations resulting from a fixed poleward shift in boreal forests and compare the radiative effects of this to changes in surface energy fluxes. CO2-concentrations and sea surface temperatures are kept fixed in order to isolate the effects of the change in vegetation patterns. Finally, these results are compared to simulations of a future climate (corresponding to 2xCO2-concentrations) both with present-day and shifted vegetation patterns.

Measurements of VOC fluxes by dynamic plant and soil chambers in wheat and maize crop near Paris with a PTR-Qi-TOF-MS: Quantification and response to environmental and physiological drivers.

NASA Astrophysics Data System (ADS)

Gonzaga-Gomez, Lais; Boissard, Christophe; Ciuraru, Raluca; Lafouge, Florence; Zurfluh, Olivier; Buysse, Pauline; Decuq, Céline; Fanucci, Olivier; Gueudet, Jean-Christophe; Gros, Valérie; Sarda, Roland; Zannoni, Nora; Loubet, Benjamin

2017-04-01

Volatile organic compounds (VOC) play an important role in the chemistry of the atmosphere as precursors of secondary pollutants such as ozone and organic aerosols. A large variety of VOC are exchanged between plants (BVOC) and the atmosphere. Their fluxes are strongly dependent on environmental factors (temperature, light, biotic and abiotic stress) and vary greatly among plant species. Only few studies focused on BVOC emissions by agricultural plants and were mostly carried in North America. However, agricultural lands occupy 51% of the total country area in France, with wheat being one of the most important crop. We used a PTR-Qi-TOF-MS (national instrument within the ANAEE-France framework) and dynamic chambers to measure BVOC emissions from plant and soil compartments of a wheat and a maize crop near Paris (FR-GRI ICOS site). More than 700 masses were detected thanks to the resolution and sensitivity of this new instrument. We analyze the emission response to light, temperature and stomatal aperture in order to explain the mechanisms of BVOC exchanges by wheat plants. We investigate the emission differences between soil and plant compartment, and between wheat and maize crops. Acetone (m/z 59.049) was the predominant volatile compound in the emissions from wheat. Both methanol (m/z 33.033) and acetaldehyde (m/z 45.033) were also quite abundantly emitted but were less than half the acetone emissions. Other masses detected in relative importance in this study were m/z 63.026 (possible DMS), m/z 93.033 (not identified), m/z 69.069 (isoprene), m/z 57.069 (not identified), m/z 83.085 (possible green leaf volatiles), m/z 73.064 (methyl ethyl ketone). Their emissions were around 7 times smaller than the emissions of acetone. On the other hand we observed a deposition for, mainly, m/z 75.044 (hydroxyacetone) and m/z 61.028 (acetic acid). Methanol presented both positive and negative fluxes witch could indicate either emission or absorption of this compound by the plant, respectively.

Simulation of the interannual variations of biogenic emissions of volatile organic compounds in China: Impacts on tropospheric ozone and secondary organic aerosol

NASA Astrophysics Data System (ADS)

Fu, Y.; Liao, H.

2012-12-01

We use the MEGAN (Model of emissions of Gases and Aerosols from Nature) module embedded within the global three-dimensional Goddard Earth Observing System chemical transport model (GEOS-Chem) to simulate the interannual variations in biogenic volatile organic compound (BVOC) emissions and concentrations of ozone and secondary organic aerosols (SOA) in China over years 2001-2006. To have better representation of biogenic emissions, we have updated in the model the land cover and leaf area index in China using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite measurements, and we have developed a new classification of vegetation with 21 plant functional types. Estimated annual BVOC emission in China averaged over 2001-2006 is 18.85 Tg C yr-1, in which emissions of isoprene, monoterpenes, and other reactive volatile organic compounds account for 50.9%, 15.0%, and 34.1%, respectively. The simulated BVOC emissions in China have large interannual variations. The values of regionally averaged absolute percent departure from the mean (APDM) of isoprene emissions are in the range of 21-42% in January and 15-28% in July. The APDM values of monoterpene emissions are 14-32% in January and 10-21% in July, which are generally smaller than those of isoprene emissions. Model results indicate that the interannual variations in isoprene emissions are more dependent on variations in meteorological fields, whereas the interannual variations in monoterpene emissions are more sensitive to changes in vegetation parameters. With fixed anthropogenic emissions, as a result of the variations in both meteorological parameters and vegetation, simulated O3 concentrations show interannual variations of 0.8-5 ppbv (or largest APDM values of 4-15%), and simulated SOA shows APDM values of 5-15% in southwestern China in January as well as 10-25% in southeastern and 20-35% in northeastern China in July. On a regional mean basis, the interannual variations in BVOCs alone can lead to 2-5% differences in simulated O3 and SOA in summer.

Simulation of the interannual variations of biogenic emissions of volatile organic compounds in China: Impacts on tropospheric ozone and secondary organic aerosol

NASA Astrophysics Data System (ADS)

Fu, Yu; Liao, Hong

2012-11-01

We use the MEGAN (Model of emissions of Gases and Aerosols from Nature) module embedded within the global three-dimensional Goddard Earth Observing System chemical transport model (GEOS-Chem) to simulate the interannual variations in biogenic volatile organic compound (BVOC) emissions and concentrations of ozone and secondary organic aerosols (SOA) in China over years 2001-2006. To have better representation of biogenic emissions, we have updated in the model the land cover and leaf area index in China using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite measurements, and we have developed a new classification of vegetation with 21 plant functional types. Estimated annual BVOC emission in China averaged over 2001-2006 is 18.85 Tg C yr-1, in which emissions of isoprene, monoterpenes, and other reactive volatile organic compounds account for 50.9%, 15.0%, and 34.1%, respectively. The simulated BVOC emissions in China have large interannual variations. The values of regionally averaged absolute percent departure from the mean (APDM) of isoprene emissions are in the range of 21-42% in January and 15-28% in July. The APDM values of monoterpene emissions are 14-32% in January and 10-21% in July, which are generally smaller than those of isoprene emissions. Model results indicate that the interannual variations in isoprene emissions are more dependent on variations in meteorological fields, whereas the interannual variations in monoterpene emissions are more sensitive to changes in vegetation parameters. With fixed anthropogenic emissions, as a result of the variations in both meteorological parameters and vegetation, simulated O3 concentrations show interannual variations of 0.8-5 ppbv (or largest APDM values of 4-15%), and simulated SOA shows APDM values of 5-15% in southwestern China in January as well as 10-25% in southeastern and 20-35% in northeastern China in July. On a regional mean basis, the interannual variations in BVOCs alone can lead to 2-5% differences in simulated O3 and SOA in summer.

Metabolite Profiling Reveals a Specific Response in Tomato to Predaceous Chrysoperla carnea Larvae and Herbivore(s)-Predator Interactions with the Generalist Pests Tetranychus urticae and Myzus persicae.

PubMed

Errard, Audrey; Ulrichs, Christian; Kühne, Stefan; Mewis, Inga; Mishig, Narantuya; Maul, Ronald; Drungowski, Mario; Parolin, Pia; Schreiner, Monika; Baldermann, Susanne

2016-01-01

The spider mite Tetranychus urticae Koch and the aphid Myzus persicae (Sulzer) both infest a number of economically significant crops, including tomato (Solanum lycopersicum). Although used for decades to control pests, the impact of green lacewing larvae Chrysoperla carnea (Stephens) on plant biochemistry was not investigated. Here, we used profiling methods and targeted analyses to explore the impact of the predator and herbivore(s)-predator interactions on tomato biochemistry. Each pest and pest-predator combination induced a characteristic metabolite signature in the leaf and the fruit thus, the plant exhibited a systemic response. The treatments had a stronger impact on non-volatile metabolites including abscisic acid and amino acids in the leaves in comparison with the fruits. In contrast, the various biotic factors had a greater impact on the carotenoids in the fruits. We identified volatiles such as myrcene and α-terpinene which were induced by pest-predator interactions but not by single species, and we demonstrated the involvement of the phytohormone abscisic acid in tritrophic interactions for the first time. More importantly, C. carnea larvae alone impacted the plant metabolome, but the predator did not appear to elicit particular defense pathways on its own. Since the presence of both C. carnea larvae and pest individuals elicited volatiles which were shown to contribute to plant defense, C. carnea larvae could therefore contribute to the reduction of pest infestation, not only by its preying activity, but also by priming responses to generalist herbivores such as T. urticae and M. persicae. On the other hand, the use of C. carnea larvae alone did not impact carotenoids thus, was not prejudicial to the fruit quality. The present piece of research highlights the specific impact of predator and tritrophic interactions with green lacewing larvae, spider mites, and aphids on different components of the tomato primary and secondary metabolism for the first time, and provides cues for further in-depth studies aiming to integrate entomological approaches and plant biochemistry.

Metabolite Profiling Reveals a Specific Response in Tomato to Predaceous Chrysoperla carnea Larvae and Herbivore(s)-Predator Interactions with the Generalist Pests Tetranychus urticae and Myzus persicae

PubMed Central

Errard, Audrey; Ulrichs, Christian; Kühne, Stefan; Mewis, Inga; Mishig, Narantuya; Maul, Ronald; Drungowski, Mario; Parolin, Pia; Schreiner, Monika; Baldermann, Susanne

2016-01-01

The spider mite Tetranychus urticae Koch and the aphid Myzus persicae (Sulzer) both infest a number of economically significant crops, including tomato (Solanum lycopersicum). Although used for decades to control pests, the impact of green lacewing larvae Chrysoperla carnea (Stephens) on plant biochemistry was not investigated. Here, we used profiling methods and targeted analyses to explore the impact of the predator and herbivore(s)-predator interactions on tomato biochemistry. Each pest and pest-predator combination induced a characteristic metabolite signature in the leaf and the fruit thus, the plant exhibited a systemic response. The treatments had a stronger impact on non-volatile metabolites including abscisic acid and amino acids in the leaves in comparison with the fruits. In contrast, the various biotic factors had a greater impact on the carotenoids in the fruits. We identified volatiles such as myrcene and α-terpinene which were induced by pest-predator interactions but not by single species, and we demonstrated the involvement of the phytohormone abscisic acid in tritrophic interactions for the first time. More importantly, C. carnea larvae alone impacted the plant metabolome, but the predator did not appear to elicit particular defense pathways on its own. Since the presence of both C. carnea larvae and pest individuals elicited volatiles which were shown to contribute to plant defense, C. carnea larvae could therefore contribute to the reduction of pest infestation, not only by its preying activity, but also by priming responses to generalist herbivores such as T. urticae and M. persicae. On the other hand, the use of C. carnea larvae alone did not impact carotenoids thus, was not prejudicial to the fruit quality. The present piece of research highlights the specific impact of predator and tritrophic interactions with green lacewing larvae, spider mites, and aphids on different components of the tomato primary and secondary metabolism for the first time, and provides cues for further in-depth studies aiming to integrate entomological approaches and plant biochemistry. PMID:27610113

Increasing leaf hydraulic conductance with transpiration rate minimizes the water potential drawdown from stem to leaf

PubMed Central

Simonin, Kevin A.; Burns, Emily; Choat, Brendan; Barbour, Margaret M.; Dawson, Todd E.; Franks, Peter J.

2015-01-01

Leaf hydraulic conductance (k leaf) is a central element in the regulation of leaf water balance but the properties of k leaf remain uncertain. Here, the evidence for the following two models for k leaf in well-hydrated plants is evaluated: (i) k leaf is constant or (ii) k leaf increases as transpiration rate (E) increases. The difference between stem and leaf water potential (ΔΨstem–leaf), stomatal conductance (g s), k leaf, and E over a diurnal cycle for three angiosperm and gymnosperm tree species growing in a common garden, and for Helianthus annuus plants grown under sub-ambient, ambient, and elevated atmospheric CO2 concentration were evaluated. Results show that for well-watered plants k leaf is positively dependent on E. Here, this property is termed the dynamic conductance, k leaf(E), which incorporates the inherent k leaf at zero E, which is distinguished as the static conductance, k leaf(0). Growth under different CO2 concentrations maintained the same relationship between k leaf and E, resulting in similar k leaf(0), while operating along different regions of the curve owing to the influence of CO2 on g s. The positive relationship between k leaf and E minimized variation in ΔΨstem–leaf. This enables leaves to minimize variation in Ψleaf and maximize g s and CO2 assimilation rate over the diurnal course of evaporative demand. PMID:25547915

[Latitude variation mechanism of leaf traits of Metasequoia glyptostroboides in eastern coastal China].

PubMed

Guo, Wei Hong; Wang, Hua; Yu, Mu Kui; Wu, Tong Gui; Han, You Zhi

2017-03-18

We analyzed the rules of Metasequoia glyptostroboides along with latitude, including leaf length, leaf width, leaf perimeter, leaf area, ratio of leaf length to width, specific leaf area (SLA), and leaf dry mass based on eight stands growing at different latitudes in the coastal area of eastern China, as well as their relationships with climatic and soil factors. The results showed that the leaf length, leaf width and leaf perimeter increased with increasing latitude, while the leaf area and SLA firstly increased and then decreased. The mean annual temperature and annual precipitation were the major environmental factors affecting the leaf traits along latitude gradient. With the increase of soil N content, the SLA decreased firstly and then increased, while the leaf mass decreased significantly. With the increase of soil P content, the SLA increased, and the leaf mass decreased significantly.

Research on spatial distribution of photosynthetic characteristics of Winter Wheat

NASA Astrophysics Data System (ADS)

Yan, Q. Q.; Zhou, Q. Y.; Zhang, B. Z.; Han, X.; Han, N. N.; Li, S. M.

2018-03-01

In order to explore the spatial distribution of photosynthetic characteristics of winter wheat leaf, the photosynthetic rate on different parts of leaf (leaf base-leaf middle-leaf apex) and that on each canopy (top layer-middle layer-bottom layer) leaf during the whole growth period of winter wheat were measured. The variation of photosynthetic rate with PAR and the spatial distribution of winter wheat leaf during the whole growth periods were analysed. The results showed that the photosynthetic rate of different parts of winter wheat increased with the increase of PAR, which was showed as leaf base>leaf middle>leaf apex. In the same growth period, photosynthetic rate in different parts of the tablet was showed as leaf middle>leaf base>leaf apex. For the different canopy layer of winter wheat, the photosynthetic rate of the top layer leaf was significantly greater than that of the middle layer and lower layer leaf. The photosynthetic rate of the top layer leaf was the largest in the leaf base position. The photosynthetic rate of leaf of the same canopy layer at different growth stages were showed as tasseling stage >grain filling stage > maturation stage.

A Constrained Maximization Model for inspecting the impact of leaf shape on optimal leaf size and stoma resistance

NASA Astrophysics Data System (ADS)

Ding, J.; Johnson, E. A.; Martin, Y. E.

2017-12-01

Leaf is the basic production unit of plants. Water is the most critical resource of plants. Its availability controls primary productivity of plants by affecting leaf carbon budget. To avoid the damage of cavitation from lowering vein water potential t caused by evapotranspiration, the leaf must increase the stomatal resistance to reduce evapotranspiration rate. This comes at the cost of reduced carbon fixing rate as increasing stoma resistance meanwhile slows carbon intake rate. Studies suggest that stoma will operate at an optimal resistance to maximize the carbon gain with respect to water. Different plant species have different leaf shapes, a genetically determined trait. Further, on the same plant leaf size can vary many times in size that is related to soil moisture, an indicator of water availability. According to metabolic scaling theory, increasing leaf size will increase total xylem resistance of vein, which may also constrain leaf carbon budget. We present a Constrained Maximization Model of leaf (leaf CMM) that incorporates metabolic theory into the coupling of evapotranspiration and carbon fixation to examine how leaf size, stoma resistance and maximum net leaf primary productivity change with petiole xylem water potential. The model connects vein network structure to leaf shape and use the difference between petiole xylem water potential and the critical minor vein cavitation forming water potential as the budget. The CMM shows that both maximum net leaf primary production and optimal leaf size increase with petiole xylem water potential while optimal stoma resistance decreases. Narrow leaf has overall lower optimal leaf size and maximum net leaf carbon gain and higher optimal stoma resistance than those of broad leaf. This is because with small width to length ratio, total xylem resistance increases faster with leaf size. Total xylem resistance of narrow leaf increases faster with leaf size causing higher average and marginal cost of xylem water potential with respect to net leaf carbon gain. With same leaf area, total xylem resistance of narrow leaf is higher than broad leaf. Given same stoma resistance and petiole water potential, narrow leaf will lose more xylem water potential than broad leaf. Consequently, narrow leaf has smaller size and higher stoma resistance at optimum.

Assessing soybean leaf area and leaf biomass by spectral measurements

NASA Technical Reports Server (NTRS)

Holben, B. N.; Tucker, C. J.; Fan, C. J.

1979-01-01

Red and photographic infrared spectral radiances were correlated with soybean total leaf area index, green leaf area index, chlorotic leaf area index, green leaf biomass, chlorotic leaf biomass, and total biomass. The most significant correlations were found to exist between the IR/red radiance ratio data and green leaf area index and/or green leaf biomass (r squared equals 0.85 and 0.86, respectively). These findings demonstrate that remote sensing data can supply information basic to soybean canopy growth, development, and status by nondestructive determination of the green leaf area or green leaf biomass.

Relationships of leaf dark respiration to leaf nitrogen, specific leaf area and leaf life-span: a test across biomes and functional groups

Treesearch

Peter B. Reich; Michael B. Walters; David S. Ellsworth; [and others; [Editor’s note: James M.. Vose is the SRS co-author for this publication.

1998-01-01

Based on prior evidence of coordinated multiple leaf trait scaling, the authors hypothesized that variation among species in leaf dark respiration rate (Rd) should scale with variation in traits such as leaf nitrogen (N), leaf life-span, specific leaf area (SLA), and net photosynthetic capacity (Amax). However, it is not known whether such scaling, if it exists, is...

Nebulized water cooling of the canopy affects leaf temperature, berry composition and wine quality of Sauvignon blanc.

PubMed

Paciello, Pericle; Mencarelli, Fabio; Palliotti, Alberto; Ceccantoni, Brunella; Thibon, Cécile; Darriet, Philippe; Pasquini, Massimiliano; Bellincontro, Andrea

2017-03-01

The present paper details a new technique based on spraying nebulized water on vine canopy to counteract the negative impact of the current wave of hot summers with temperatures above 30 °C, which usually determine negative effects on vine yield, grape composition and wine quality. The automatized spraying system was able to maintain air temperature at below 30 °C (the threshold temperature to start spraying) for all of August 2013, when in the canopy of uncooled vines the temperature was as high as 36 °C. The maintenance of temperature below 30 °C reduced leaf stress linked to high temperature and irradiance regimes as highlighted by the decrease of H 2 O 2 content and catalase activity in the leaves. A higher amount of total polyphenols and organic acids and lower sugars characterized the grapes of cooled vines. Wine from these grapes had a higher content of some volatile thiols like 3-sulfanylhexanol (3SH) and 3-sulfanylhexylacetate (3SHA), and lower content of 4-methyl-4-sulfanylpentan-2-one (4MSP). Under conditions of high temperature and irradiance regimes, water nebulization on the vine canopy can represent a valid solution to reduce and/or avoid oxidative stress and associated effects in the leaves, ensure a regular berry ripening and maintain high wine quality. The consumption of water during nebulization was acceptable, being 180 L ha -1 min -1 , which lasted an average of about 1 min to reduce the temperature below the threshold value of 30 °C. A total of 85-90 hL (from 0.8 to 0.9 mm) of water per hectare per day was required. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Functional indicators of response mechanisms to nitrogen deposition, ozone, and their interaction in two Mediterranean tree species

PubMed Central

Palma, Adriano; Salvatori, Elisabetta; Basile, Adriana; Maresca, Viviana; Asadi Karam, Elham; Manes, Fausto

2017-01-01

The effects of nitrogen (N) deposition, tropospheric ozone (O3) and their interaction were investigated in two Mediterranean tree species, Fraxinus ornus L. (deciduous) and Quercus ilex L. (evergreen), having different leaf habits and resource use strategies. An experiment was conducted under controlled condition to analyse how nitrogen deposition affects the ecophysiological and biochemical traits, and to explore how the nitrogen-induced changes influence the response to O3. For both factors we selected realistic exposures (20 kg N ha-1 yr-1 and 80 ppb h for nitrogen and O3, respectively), in order to elucidate the mechanisms implemented by the plants. Nitrogen addition resulted in higher nitrogen concentration at the leaf level in F. ornus, whereas a slight increase was detected in Q. ilex. Nitrogen enhanced the maximum rate of assimilation and ribulose 1,5-bisphosphate regeneration in both species, whereas it influenced the light harvesting complex only in the deciduous F. ornus that was also affected by O3 (reduced assimilation rate and accelerated senescence-related processes). Conversely, Q. ilex developed an avoidance mechanism to cope with O3, confirming a substantial O3 tolerance of this species. Nitrogen seemed to ameliorate the harmful effects of O3 in F. ornus: the hypothesized mechanism of action involved the production of nitrogen oxide as the first antioxidant barrier, followed by enzymatic antioxidant response. In Q. ilex, the interaction was not detected on gas exchange and photosystem functionality; however, in this species, nitrogen might stimulate an alternative antioxidant response such as the emission of volatile organic compounds. Antioxidant enzyme activity was lower in plants treated with both O3 and nitrogen even though reactive oxygen species production did not differ between the treatments. PMID:28973038

Dynamic Balancing of Isoprene Carbon Sources Reflects Photosynthetic and Photorespiratory Responses to Temperature Stress1[W][OPEN

PubMed Central

Chambers, Jeffrey; Alves, Eliane G.; Teixeira, Andrea; Garcia, Sabrina; Holm, Jennifer; Higuchi, Niro; Manzi, Antonio; Abrell, Leif; Fuentes, Jose D.; Nielsen, Lars K.; Torn, Margaret S.; Vickers, Claudia E.

2014-01-01

The volatile gas isoprene is emitted in teragrams per annum quantities from the terrestrial biosphere and exerts a large effect on atmospheric chemistry. Isoprene is made primarily from recently fixed photosynthate; however, alternate carbon sources play an important role, particularly when photosynthate is limiting. We examined the relative contribution of these alternate carbon sources under changes in light and temperature, the two environmental conditions that have the strongest influence over isoprene emission. Using a novel real-time analytical approach that allowed us to examine dynamic changes in carbon sources, we observed that relative contributions do not change as a function of light intensity. We found that the classical uncoupling of isoprene emission from net photosynthesis at elevated leaf temperatures is associated with an increased contribution of alternate carbon. We also observed a rapid compensatory response where alternate carbon sources compensated for transient decreases in recently fixed carbon during thermal ramping, thereby maintaining overall increases in isoprene production rates at high temperatures. Photorespiration is known to contribute to the decline in net photosynthesis at high leaf temperatures. A reduction in the temperature at which the contribution of alternate carbon sources increased was observed under photorespiratory conditions, while photosynthetic conditions increased this temperature. Feeding [2-13C]glycine (a photorespiratory intermediate) stimulated emissions of [13C1–5]isoprene and 13CO2, supporting the possibility that photorespiration can provide an alternate source of carbon for isoprene synthesis. Our observations have important implications for establishing improved mechanistic predictions of isoprene emissions and primary carbon metabolism, particularly under the predicted increases in future global temperatures. PMID:25318937

Nitrogen Supply Influences Herbivore-Induced Direct and Indirect Defenses and Transcriptional Responses in Nicotiana attenuata[w

PubMed Central

Lou, Yonggen; Baldwin, Ian T.

2004-01-01

Although nitrogen (N) availability is known to alter constitutive resistance against herbivores, its influence on herbivore-induced responses, including signaling pathways, transcriptional signatures, and the subsequently elicited chemical defenses is poorly understood. We used the native tobacco, Nicotiana attenuata, which germinates in the postfire environment and copes with large changes in soil N during postfire succession, to compare a suite of Manduca sexta- and elicitor-induced responses in plants grown under high- and low-N (LN) supply rates. LN supply decreased relative growth rates and biomass by 35% at 40 d compared to high-N plants; furthermore, it also attenuated (by 39 and 60%) the elicitor-induced jasmonate and salicylate bursts, two N-intensive direct defenses (nicotine and trypsin proteinase inhibitors, albeit by different mechanisms), and carbon-containing nonvolatile defenses (rutin, chlorogenic acid, and diterpene glycosides), but did not affect the induced release of volatiles (cis-α-bergamotene and germacrene A), which function as indirect defenses. M. sexta and methyl jasmonate-induced transcriptional responses measured with a microarray enriched in herbivore-induced genes were also substantially reduced in plants grown under LN supply rates. In M. sexta-attacked LN plants, only 36 (45%) up-regulated and 46 (58%) down-regulated genes showed the same regulation as those in attacked high-N plants. However, transcriptional responses frequently directly countered the observed metabolic changes. Changes in a leaf's sensitivity to elicitation, an attacked leaf's waning ability to export oxylipin wound signals, and/or resource limitations in LN plants can account for the observed results, underscoring the conclusion that defense activation is a resource-intensive response. PMID:15133153

Aggregation pheromone of the cereal leaf beetle: field evaluation and emission from males in the laboratory.

PubMed

Rao, Sujaya; Cossé, Allard A; Zilkowski, Bruce W; Bartelt, Robert J

2003-09-01

The previously identified, male-specific compound of the cereal leaf beetle (CLB, Chrysomelidae; Oulema melanopus), (E)-8-hydroxy-6-methyl-6-octen-3-one, was studied further with respect to field activity and emission rate from male beetles. In a 5-week field experiment in Oregon, the compound was shown to function as an aggregation pheromone in attracting male and female CLBs migrating from overwintering sites in spring. Traps baited with the synthetic compound (500 microg per rubber septum) caught 3.3 times more CLBs than control traps. Lower doses of the pheromone (50 and 150 microg) were less attractive than the 500 microg dose. One relatively abundant, volatile compound from the host plant (oats), (Z)-3-hexenyl acetate, that elicited responses from beetle antennae was not attractive, either by itself or as a synergist of the pheromone. Both sexes were captured about equally for all treatments. We also measured daily pheromone emission by male beetles in the laboratory. Individual males feeding on oat seedlings under greenhouse conditions emitted as much as 6 microg per day, which is about 500 times higher than had been previously observed under incubator conditions. The pheromone emission rate was at least five times higher during the day than at night, and in one male, emission spanned a period of 28 d. The release rate of synthetic pheromone from the 500 microg septa was very similar to the maximum from single males; thus, future experiments should evaluate even higher doses. The field results indicate that the pheromone has potential as a monitoring tool for early detection of CLBs as they move from their overwintering sites into newly planted cereal crops in spring.

Functional indicators of response mechanisms to nitrogen deposition, ozone, and their interaction in two Mediterranean tree species.

PubMed

Fusaro, Lina; Palma, Adriano; Salvatori, Elisabetta; Basile, Adriana; Maresca, Viviana; Asadi Karam, Elham; Manes, Fausto

2017-01-01

The effects of nitrogen (N) deposition, tropospheric ozone (O3) and their interaction were investigated in two Mediterranean tree species, Fraxinus ornus L. (deciduous) and Quercus ilex L. (evergreen), having different leaf habits and resource use strategies. An experiment was conducted under controlled condition to analyse how nitrogen deposition affects the ecophysiological and biochemical traits, and to explore how the nitrogen-induced changes influence the response to O3. For both factors we selected realistic exposures (20 kg N ha-1 yr-1 and 80 ppb h for nitrogen and O3, respectively), in order to elucidate the mechanisms implemented by the plants. Nitrogen addition resulted in higher nitrogen concentration at the leaf level in F. ornus, whereas a slight increase was detected in Q. ilex. Nitrogen enhanced the maximum rate of assimilation and ribulose 1,5-bisphosphate regeneration in both species, whereas it influenced the light harvesting complex only in the deciduous F. ornus that was also affected by O3 (reduced assimilation rate and accelerated senescence-related processes). Conversely, Q. ilex developed an avoidance mechanism to cope with O3, confirming a substantial O3 tolerance of this species. Nitrogen seemed to ameliorate the harmful effects of O3 in F. ornus: the hypothesized mechanism of action involved the production of nitrogen oxide as the first antioxidant barrier, followed by enzymatic antioxidant response. In Q. ilex, the interaction was not detected on gas exchange and photosystem functionality; however, in this species, nitrogen might stimulate an alternative antioxidant response such as the emission of volatile organic compounds. Antioxidant enzyme activity was lower in plants treated with both O3 and nitrogen even though reactive oxygen species production did not differ between the treatments.

Sitophilus granarius L. (Coleoptera) Toxicity and Biological Activities of the Essential Oils of Tanacetum macrophyllum (Waldst. & Kit.) Schultz Bip.

PubMed

Polatoğlu, Kaan; Karakoç, Ömer Cem; Demirci, Betül; Gören, Nezhun; Can Başer, Kemal Hüsnü

2015-01-01

Insecticides of the natural origin are an important alternative to the synthetic insecticides that are being employed for the preserving stored products. The volatiles obtained from T. cinerariifolium (=Pyrethrum cinerariifolium) is being used for many types of insecticidal applications; however there is a very little information on the insecticidal activity of the essential oils of other Tanacetum species. The main purpose of the present study is to determine the chemical composition of T. macrophyllum (Waldst. & Kit.) Schultz Bip. essential oils and evaluate their insecticidal activity against S. granarius as well as its other beneficial biological activities. Highest contact toxicity was observed in the leaf oil of (88.93%) against S. granarius. The flower oil showed considerable fumigant toxicity against L. minor at 10 mg/mL application concentration (61.86 %) when compared with other samples at the same concentration. The highest DPPH (2,2-Diphenyl-1-picrylhydrazyl) scavenging activity (47.7%) and phosphomolybdenum reducing activity was observed also for the flower oil of T. macrophyllum at 10 mg/mL concentration. The essential oils were analyzed by GC, GC/MS. The flower and leaf oils were characterized with γ-eudesmol 21.5%, (E)-sesquilavandulol 20.3%, copaborneol 8.5% and copaborneol 14.1%, 1,8-cineole 11%, bornyl acetate 9.6%, borneol 6.3% respectively. AHC analysis of the qualitative and quantitative data obtained from the essential oil composition of the T. macrophyllum essential oil from the present research and previous reports pointed out that two different chemotypes could be proposed with current findings which are p-methyl benzyl alcohol/ cadinene and eudesmane chemotypes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jardine, Kolby

In conjunction with the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility GoAmazon campaign, the Terrestrial Ecosystem Science (TES)-funded Green Ocean Amazon (GoAmazon 2014/15) terrestrial ecosystem project (Geco) was designed to: • evaluate the strengths and weaknesses of leaf-level algorithms for biogenic volatile organic compounds (BVOCs) emissions in Amazon forests near Manaus, Brazil, and • conduct mechanistic field studies to characterize biochemical and physiological processes governing leaf- and landscape-scale tropical forest BVOC emissions, and the influence of environmental drivers that are expected to change with a warming climate. Through a close interaction between modeling and observationalmore » activities, including the training of MS and PhD graduate students, post-doctoral students, and technicians at the National Institute for Amazon Research (INPA), the study aimed at improving the representation of BVOC-mediated biosphere-atmosphere interactions and feedbacks under a warming climate. BVOCs can form cloud condensation nuclei (CCN) that influence precipitation dynamics and modify the quality of down welling radiation for photosynthesis. However, our ability to represent these coupled biosphere-atmosphere processes in Earth system models suffers from poor understanding of the functions, identities, quantities, and seasonal patterns of BVOC emissions from tropical forests as well as their biological and environmental controls. The Model of Emissions of Gases and Aerosols from Nature (MEGAN), the current BVOC sub-model of the Community Earth System Model (CESM), was evaluated to explore mechanistic controls over BVOC emissions. Based on that analysis, a combination of observations and experiments were studied in forests near Manaus, Brazil, to test existing parameterizations and algorithm structures in MEGAN. The model was actively modified as needed to improve tropical BVOC emission simulations on a regional scale.« less

Physiological Disorders in Closed Environment-Grown Crops for Space Life Support

NASA Astrophysics Data System (ADS)

Wheeler, Raymond; Morrow, Robert

Crop production for life support systems in space will require controlled environments where temperature, humidity, CO2, and light might differ from natural environments where plants evolved. Physiological disorders, i.e., abnormal plant growth and development, can occur under these controlled environments. Among the most common of these disorders are Ca deficiency injuries such as leaf tipburn (e.g., lettuce), blossom-end-rot in fruits (e.g., tomato and pepper), and internal tissue necrosis in fruits or tubers (e.g., cucumber and potato). Increased Ca nutrition to the plants typically has little effect on these disorders, but slowing overall growth or providing better air circulation to increase transpiration can be effective. A second common disorder is oedema or intumescence, which appears as callus-like growth or galls on leaves (e.g., sweetpotato, potato, pepper, and tomato). This disorder can be reduced by increasing the near UV radiation ( 300-400 nm) to the plants. Leaf injury and necrosis can occur under long photoperiods (e.g., tomato, potato, and pepper) and at super-elevated (i.e., ¿ than 4000 mol mol-1) CO2 concentrations (e.g., soybean, potato, and radish), and these can be managed by reducing the photoperiod and CO2 concentration, respectively. Lack of blue light in the spectrum (e.g., under red LEDs or LPS lamps) can result in leggy growth and/or leaves lacking in chlorophyll (e.g., wheat, bean, and radish). Volatile organic compounds (VOCs), most commonly ethylene, can accumulate in tightly closed systems and result in a variety of negative responses. Most of these disorders can be mitigated by altering the environmental set-points or by using more resistant cultivars.

Performance of sorghum cultivars for biomass quality and biomethane yield grown in semi-arid area of Pakistan.

PubMed

Hassan, Muhammad Umair; Chattha, Muhammad Umer; Mahmood, Athar; Sahi, Shahbaz Talib

2018-05-01

Biomass is a promising renewable energy source and its significance is escalating in the context of climate change and depletion of fossil foils. This study was conducted for two consecutive years 2016 and 2017, using five sorghum cultivars, i.e., JS-263, Jawar-2011, Hagari, JS-2002, and YS-2016, in order to determine the best cultivars in terms of dry matter yield, chemical composition, and biomethane yield grown under semi-arid conditions in Pakistan. The results revealed that sorghum cultivars responded differently in terms of growth, biomass yield, chemical composition, and methane yield. Cultivars Jawar-2011 produced maximum leaf area index, leaf area duration, crop growth rate, plant height, and leaves per plant, however, they were comparable with Sorghum-2016, whereas cultivar JS-2002 performed poorly among the tested cultivars. Similarly, cultivar Jawar-2011 produced maximum dry matter yield (16.37 t ha -1 ) similar to that of YS-2016, further cultivar JS-2002 performed poorly and gave lower dry matter yield (12.87 t ha -1 ). The maximum protein concentration (10.95), neutral detergent fibers (61.20), and lignin contents (5.55) found in Jawar-2011 were comparable with those in YS-2016, while the lowest neutral detergent fiber and lignin contents were found in JS-2002. Although JS-2002 produced the highest specific methane yield per kilogram of volatile solids, it was overcompensated by Jawar-2011 owing to higher dry matter yield per hectare. These results suggested that cultivar Jawar-2011 can be grown successfully in semi-arid conditions of Pakistan in order to get good biomass yield along with higher methane yield.

Dynamic balancing of isoprene carbon sources reflects photosynthetic and photorespiratory responses to temperature stress.

PubMed

Jardine, Kolby; Chambers, Jeffrey; Alves, Eliane G; Teixeira, Andrea; Garcia, Sabrina; Holm, Jennifer; Higuchi, Niro; Manzi, Antonio; Abrell, Leif; Fuentes, Jose D; Nielsen, Lars K; Torn, Margaret S; Vickers, Claudia E

2014-12-01

The volatile gas isoprene is emitted in teragrams per annum quantities from the terrestrial biosphere and exerts a large effect on atmospheric chemistry. Isoprene is made primarily from recently fixed photosynthate; however, alternate carbon sources play an important role, particularly when photosynthate is limiting. We examined the relative contribution of these alternate carbon sources under changes in light and temperature, the two environmental conditions that have the strongest influence over isoprene emission. Using a novel real-time analytical approach that allowed us to examine dynamic changes in carbon sources, we observed that relative contributions do not change as a function of light intensity. We found that the classical uncoupling of isoprene emission from net photosynthesis at elevated leaf temperatures is associated with an increased contribution of alternate carbon. We also observed a rapid compensatory response where alternate carbon sources compensated for transient decreases in recently fixed carbon during thermal ramping, thereby maintaining overall increases in isoprene production rates at high temperatures. Photorespiration is known to contribute to the decline in net photosynthesis at high leaf temperatures. A reduction in the temperature at which the contribution of alternate carbon sources increased was observed under photorespiratory conditions, while photosynthetic conditions increased this temperature. Feeding [2-(13)C]glycine (a photorespiratory intermediate) stimulated emissions of [(13)C1-5]isoprene and (13)CO2, supporting the possibility that photorespiration can provide an alternate source of carbon for isoprene synthesis. Our observations have important implications for establishing improved mechanistic predictions of isoprene emissions and primary carbon metabolism, particularly under the predicted increases in future global temperatures. © 2014 American Society of Plant Biologists. All Rights Reserved.

Response of Leaf Water Potential, Stomatal Resistance, and Leaf Rolling to Water Stress

PubMed Central

O'Toole, John C.; Cruz, Rolando T.

1980-01-01

Numerous studies have associated increased stomatal resistance with response to water deficit in cereals. However, consideration of change in leaf form seems to have been neglected. The response of adaxial and abaxial stomatal resistance and leaf rolling in rice to decreasing leaf water potential was investigated. Two rice cultivars were subjected to control and water stress treatments in a deep (1-meter) aerobic soil. Concurrent measurements of leaf water potential, stomatal resistance, and degree of leaf rolling were made through a 29-day period after cessation of irrigation. Kinandang Patong, an upland adapted cultivar, maintained higher dawn and midday leaf water potential than IR28, a hybrid selected in irrigated conditions. This was not explained by differences in leaf diffusive resistance or leaf rolling, and is assumed to result from a difference in root system extent. Stomatal resistance increased more on the abaxial than the adaxial leaf surface in both cultivars. This was associated with a change in leaf form or rolling inward of the upper leaf surface. Both responses, increased stomatal resistance and leaf rolling, were initiated in a similar leaf water potential range (−8 to −12 bars). Leaves of IR28 became fully rolled at leaf water potential of about −22 bars; however, total leaf diffusive resistance was only about 4 to 5 seconds per centimeter (conductance 0.25 to 0.2 centimeter per second) at that stage. Leaf diffusive resistance and degree of leaf rolling were linearly related to leaf water potential. Thus, leaf rolling in rice may be used as an estimate of the other two less obvious effects of water deficit. PMID:16661206

Leaf shrinkage with dehydration: coordination with hydraulic vulnerability and drought tolerance.

PubMed

Scoffoni, Christine; Vuong, Christine; Diep, Steven; Cochard, Hervé; Sack, Lawren

2014-04-01

Leaf shrinkage with dehydration has attracted attention for over 100 years, especially as it becomes visibly extreme during drought. However, little has been known of its correlation with physiology. Computer simulations of the leaf hydraulic system showed that a reduction of hydraulic conductance of the mesophyll pathways outside the xylem would cause a strong decline of leaf hydraulic conductance (K(leaf)). For 14 diverse species, we tested the hypothesis that shrinkage during dehydration (i.e. in whole leaf, cell and airspace thickness, and leaf area) is associated with reduction in K(leaf) at declining leaf water potential (Ψ(leaf)). We tested hypotheses for the linkage of leaf shrinkage with structural and physiological water relations parameters, including modulus of elasticity, osmotic pressure at full turgor, turgor loss point (TLP), and cuticular conductance. Species originating from moist habitats showed substantial shrinkage during dehydration before reaching TLP, in contrast with species originating from dry habitats. Across species, the decline of K(leaf) with mild dehydration (i.e. the initial slope of the K(leaf) versus Ψ(leaf) curve) correlated with the decline of leaf thickness (the slope of the leaf thickness versus Ψ(leaf) curve), as expected based on predictions from computer simulations. Leaf thickness shrinkage before TLP correlated across species with lower modulus of elasticity and with less negative osmotic pressure at full turgor, as did leaf area shrinkage between full turgor and oven desiccation. These findings point to a role for leaf shrinkage in hydraulic decline during mild dehydration, with potential impacts on drought adaptation for cells and leaves, influencing plant ecological distributions.

Plasticity of vulnerability to leaf hydraulic dysfunction during acclimation to drought in grapevines: an osmotic-mediated process.

PubMed

Martorell, Sebastian; Medrano, Hipolito; Tomàs, Magdalena; Escalona, José M; Flexas, Jaume; Diaz-Espejo, Antonio

2015-03-01

Previous studies have reported correlation of leaf hydraulic vulnerability with pressure-volume parameters related to cell turgor. This link has been explained on the basis of the effects of turgor on connectivity among cells and tissue structural integrity, which affect leaf water transport. In this study, we tested the hypothesis that osmotic adjustment to water stress would shift the leaf vulnerability curve toward more negative water potential (Ψ leaf ) by increasing turgor at low Ψ leaf . We measured leaf hydraulic conductance (K leaf ), K leaf vulnerability [50 and 80% loss of K leaf (P50 and P80 ); |Ψ leaf | at 50 and 80% loss of K leaf , respectively), bulk leaf water relations, leaf gas exchange and sap flow in two Vitis vinifera cultivars (Tempranillo and Grenache), under two water treatments. We found that P50 , P80 and maximum K leaf decreased seasonally by more than 20% in both cultivars and watering treatments. However, K leaf at 2 MPa increased threefold, while osmotic potential at full turgor and turgor loss point decreased. Our results indicate that leaf resistance to hydraulic dysfunction is seasonally plastic, and this plasticity may be mediated by osmotic adjustment. © 2014 Scandinavian Plant Physiology Society.

Hinge assembly

DOEpatents

Vandergriff, D.H.

1999-08-31

A hinge assembly is disclosed having a first leaf, a second leaf and linking member. The first leaf has a contact surface. The second leaf has a first contact surface and a second contact surface. The linking member pivotally connects to the first leaf and to the second leaf. The hinge assembly is capable of moving from a closed position to an open position. In the closed position, the contact surface of the first leaf merges with the first contact surface of the second leaf. In the open position, the contact surface of the first leaf merges with the second contact surface of the second leaf. The hinge assembly can include a seal on the contact surface of the first leaf. 8 figs.

Hinge assembly

DOEpatents

Vandergriff, David Houston

1999-01-01

A hinge assembly having a first leaf, a second leaf and linking member. The first leaf has a contact surface. The second leaf has a first contact surface and a second contact surface. The linking member pivotally connects to the first leaf and to the second leaf. The hinge assembly is capable of moving from a closed position to an open position. In the closed position, the contact surface of the first leaf merges with the first contact surface of the second leaf. In the open position, the contact surface of the first leaf merges with the second contact surface of the second leaf. The hinge assembly can include a seal on the contact surface of the first leaf.

Attraction, Oviposition Preferences, and Olfactory Responses of Corn-Infesting Ulidiidae (Diptera) to Various Host-Based Substrates.

PubMed

Owens, D; Nuessly, G S; Kendra, P E; Colquhoun, T A; Seal, D R

2017-08-01

Fresh market sweet corn (Zea mays L., convar. saccharata var. rugosa, Poales: Poaceae) ears produced in Florida are damaged by the larvae of Euxesta stigmatias Loew, Euxesta eluta Loew, and Chaetopsis massyla Walker (Diptera: Ulidiidae) that renders ears unmarketable. No standard lure exists for monitoring these pests. Oviposition substrate and attractant bioassays were designed to identify attractive substrates for further semiochemical investigation. Frass from the fall armyworm, Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctuidae), was more attractive than other ovipositional substrates tested for E. eluta and C. massyla, and resulted in greater ovipositional output. Tassel-derived armyworm frass was more attractive than leaf-derived frass for oviposition. Frass also resulted in greater oviposition output by two species. In attraction bioassays, frass was generally preferred over the corresponding corn tissue, and only C. massyla demonstrated a preference for silk-frass over tassel-frass. The most promising substrates were then evaluated by electroantennography (EAG) to quantify olfactory responses. Frass volatiles also elicited greater antennal responses than corn volatiles. With tassel-frass, greater amplitude EAG responses were recorded from immature E. eluta female antennae, while mature female E. stigmatias exhibited greater responses. Equivalent antennal response to silk-frass was observed from E. eluta. Overall, silk-frass elicited the greatest EAG responses among all three fly species. Our results indicate that armyworm frass is an important resource in the chemical ecology of corn-infesting silk flies, and this substrate warrants further investigation for potential attractants that may facilitate development of novel management tools for these pests. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Grazing-induced BVOC fluxes from a managed grassland

NASA Astrophysics Data System (ADS)

Mozaffar, Ahsan; Schoon, Niels; Bachy, Aurelie; Digrado, Anthony; Heinesch, Bernard; Aubinet, Marc; Fauconnier, Marie-laure; Delaplace, Pierre; Dujardin, Patrick; Amelynck, Crist

2017-04-01

Grassland ecosystems cover one fourth of the Earth's land surface and are both sources and sinks of Biogenic Volatile Organic Compounds (BVOCs) which play an important role in atmospheric chemistry and air pollution. The use of grassland for cattle breeding is a common practice in many parts of the world. As it has been widely demonstrated that plants emit large bursts of BVOCs when they are mechanically damaged, grass tearing and trampling during grazing are expected to induce large BVOC emissions as well. Nevertheless, to the best of our knowledge, no study has been performed on BVOC fluxes from grazed grassland yet. Therefore investigations were performed using automated dynamic chambers in a managed grassland in Belgium over the 2015 and 2016 growing season. BVOC fluxes, together with carbon dioxide (CO2) and water vapor (H2O) fluxes from grazed and undisturbed grassland were followed simultaneously using PTR-MS (Proton Transfer Reaction-Mass Spectrometry) and a LI-840 non-dispersive IR gas analyzer. In addition, air in the chamber was sampled occasionally for GC-MS (Gas Chromatography-Mass Spectrometry) analysis to assist compound identification. Significant differences between grazed and undisturbed grassland patches were observed in terms of BVOC, CO2 and H2O vapor fluxes. Grazing by cows was found to result in enhanced emissions of several BVOCs such as methanol, acetaldehyde, acetone, acetic acid and Green Leaf Volatiles (GLVs), and induced BVOC emissions generally lasted for around 5 days following a grazing event. Quantitative data on the impact of grazing on BVOC, CO2 and H2O exchange between grassland and the atmosphere will be presented, and correlations between BVOC fluxes and environmental conditions will be discussed.

Grapevine fatty acid hydroperoxide lyase generates actin-disrupting volatiles and promotes defence-related cell death

PubMed Central

Wang, Hao; Claudel, Patricia; Riemann, Michael; Hause, Bettina; Hugueney, Philippe; Nick, Peter

2018-01-01

Abstract Fatty acid hydroperoxides can generate short-chained volatile aldehydes that may participate in plant defence. A grapevine hydroperoxide lyase (VvHPL1) clustering to the CYP74B class was functionally characterized with respect to a role in defence. In grapevine leaves, transcripts of this gene accumulated rapidly to high abundance in response to wounding. Cellular functions of VvHPL1 were investigated upon heterologous expression in tobacco BY-2 cells. A C-terminal green fluorescent protein (GFP) fusion of VvHPL1 was located in plastids. The overexpression lines were found to respond to salinity stress or the bacterial elicitor harpin by increasing cell death. This signal-dependent mortality response was mitigated either by addition of exogenous jasmonic acid or by treatment with diphenyleneiodonium (DPI), an inhibitor of NADPH oxidases. By feeding different substrates to recombinantly expressed enzyme, VvHPL1 could also be functionally classified as true 13-HPL. The cognate products generated by this 13-HPL were cis-3-hexenal and trans-2-hexenal. Using a GFP-tagged actin marker line, one of these isomeric products, cis-3-hexenal, was found specifically to elicit a rapid disintegration of actin filaments. This response was not only observed in the heterologous system (tobacco BY-2), but also in a grapevine cell strain expressing this marker, as well as in leaf discs from an actin marker grape used as a homologous system. These results are discussed in the context of a role for VvHPL1 in a lipoxygenase-dependent signalling pathway triggering cell death-related defence that bifurcates from jasmonate-dependent basal immunity. PMID:29659985

Mono- and sesquiterpene release from tomato (Solanum lycopersicum) leaves upon mild and severe heat stress and through recovery: from gene expression to emission responses

PubMed Central

Pazouki, Leila; Kanagendran, Arooran; Li, Shuai; Kännaste, Astrid; Memari, Hamid Rajabi; Bichele, Rudolf; Niinemets, Ülo

2018-01-01

Plants frequently experience heat ramps of various severities, but how and to what degree plant metabolic activity recovers from mild and severe heat stress is poorly understood. In this study, we exposed the constitutive terpene emitter, Solanum. lycopersicum leaves to mild (37 and 41 °C), moderate (46 °C) and severe (49 °C) heat ramps of 5 min. and monitored foliage photosynthetic activity, lipoxygenase pathway volatile (LOX), and mono- and sesquiterpene emissions and expression of two terpene synthase genes, β-phellandrene synthase and (E)-β-caryophyllene/α-humulene synthase, through a 24 h recovery period upon return to pre-stress conditions. Leaf monoterpene emissions were dominated by β-phellandrene and sesquiterpene emissions by (E)-β-caryophyllene, and thus, these two terpene synthase genes were representative for the two volatile terpene classes. Photosynthetic characteristics partly recovered under moderate heat stress, and very limited recovery was observed under severe stress. All stress treatments resulted in elicitation of LOX emissions that declined during recovery. Enhanced mono- and sesquiterpene emissions were observed immediately after the heat treatment, but the emissions decreased even to below the control treatment during recovery between 2-10 h, and raised again by 24 h. The expression of β-phellandrene and (E)-β-caryophyllene synthase genes decreased between 2-10 h after heat stress, and recovered to pre-stress level in mild heat stress treatment by 24 h. Overall, this study demonstrates a highly sensitive heat response of terpenoid synthesis that is mainly controlled by gene level responses under mild stress, while severe stress leads to non-recoverable declines in foliage physiological and gene expression activities. PMID:29367791

Ozone reactivity of biogenic volatile organic compound (BVOC) emissions during the Southeast Oxidant and Aerosol Study (SOAS)

NASA Astrophysics Data System (ADS)

Park, J.; Guenther, A. B.; Helmig, D.

2013-12-01

Recent studies on atmospheric chemistry in the forest environment showed that the total reactivity by biogenic volatile organic compound (BVOC) emission is still not well understood. During summer 2013, an intensive field campaign (Southeast Oxidant and Aerosol Study - SOAS) took place in Alabama, U.S.A. In this study, an ozone reactivity measurement system (ORMS) was deployed for the direct determination of the reactivity of foliage emissions. The ORMS is a newly developed measurement approach, in which a known amount of ozone is added to the ozone-free air sample stream, with the ORMS measuring ozone concentration difference between before and after a glass flask flow tube reaction vessel (2-3 minutes of residence time). Emissions were also collected onto adsorbent cartridges to investigate the discrepancy between total ozone reactivity observation and reactivity calculated from identified BVOC. Leaf and canopy level experiments were conducted by deploying branch enclosures on the three dominant tree species at the site (i.e. liquidambar, white oak, loblolly pine) and by sampling ambient air above the forest canopy. For the branch enclosure experiments, BVOC emissions were sampled from a 70 L Teflon bag enclosure, purged with air scrubbed for ozone, nitrogen oxides. Each branch experiment was performed for 3-5 days to collect at least two full diurnal cycle data. In addition, BVOCs were sampled using glass tube cartridges for 2 hours during daytime and 3 - 4 hours at night. During the last week of campaign, the inlet for the ORMS was installed on the top of scaffolding tower (~30m height). The ozone loss in the reactor showed distinct diurnal cycle for all three tree species investigated, and ozone reactivity followed patterns of temperature and light intensity.

Leaf phenological characters of main tree species in urban forest of Shenyang.

PubMed

Xu, Sheng; Xu, Wenduo; Chen, Wei; He, Xingyuan; Huang, Yanqing; Wen, Hua

2014-01-01

Plant leaves, as the main photosynthetic organs and the high energy converters among primary producers in terrestrial ecosystems, have attracted significant research attention. Leaf lifespan is an adaptive characteristic formed by plants to obtain the maximum carbon in the long-term adaption process. It determines important functional and structural characteristics exhibited in the environmental adaptation of plants. However, the leaf lifespan and leaf characteristics of urban forests were not studied up to now. By using statistic, linear regression methods and correlation analysis, leaf phenological characters of main tree species in urban forest of Shenyang were observed for five years to obtain the leafing phenology (including leafing start time, end time, and duration), defoliating phenology (including defoliation start time, end time, and duration), and the leaf lifespan of the main tree species. Moreover, the relationships between temperature and leafing phenology, defoliating phenology, and leaf lifespan were analyzed. The timing of leafing differed greatly among species. The early leafing species would have relatively early end of leafing; the longer it took to the end of leafing would have a later time of completed leafing. The timing of defoliation among different species varied significantly, the early defoliation species would have relatively longer duration of defoliation. If the mean temperature rise for 1°C in spring, the time of leafing would experience 5 days earlier in spring. If the mean temperature decline for 1°C, the time of defoliation would experience 3 days delay in autumn. There is significant correlation between leaf longevity and the time of leafing and defoliation. According to correlation analysis and regression analysis, there is significant correlation between temperature and leafing and defoliation phenology. Early leafing species would have a longer life span and consequently have advantage on carbon accumulation compared with later defoliation species.

The computational complexity of elliptic curve integer sub-decomposition (ISD) method

NASA Astrophysics Data System (ADS)

Ajeena, Ruma Kareem K.; Kamarulhaili, Hailiza

2014-07-01

The idea of the GLV method of Gallant, Lambert and Vanstone (Crypto 2001) is considered a foundation stone to build a new procedure to compute the elliptic curve scalar multiplication. This procedure, that is integer sub-decomposition (ISD), will compute any multiple kP of elliptic curve point P which has a large prime order n with two low-degrees endomorphisms ψ1 and ψ2 of elliptic curve E over prime field Fp. The sub-decomposition of values k1 and k2, not bounded by ±C√n , gives us new integers k11, k12, k21 and k22 which are bounded by ±C√n and can be computed through solving the closest vector problem in lattice. The percentage of a successful computation for the scalar multiplication increases by ISD method, which improved the computational efficiency in comparison with the general method for computing scalar multiplication in elliptic curves over the prime fields. This paper will present the mechanism of ISD method and will shed light mainly on the computation complexity of the ISD approach that will be determined by computing the cost of operations. These operations include elliptic curve operations and finite field operations.

Biotic, abiotic and management controls on methanol fluxes above a temperate mountain grassland

NASA Astrophysics Data System (ADS)

Hörtnagl, Lukas; Bamberger, Ines; Graus, Martin; Ruuskanen, Taina; Schnitzhofer, Ralf; Müller, Markus; Hansel, Armin; Wohlfahrt, Georg

2010-05-01

It was previously hypothesised that (i) stomatal conductance and plant growth play a key role in the emission of methanol (Hüve et al. 2007, Niinemets et al. 2004), (ii) methanol fluxes increase with air temperature (Niinemets and Reichstein 2003), and (iii) during cutting (leaf wounding) events and during drying high amounts of methanol are emitted into the atmosphere (Davison et al. 2008). Methanol fluxes were measured above a managed, temperate mountain grassland in Stubai Valley (Tyrol, Austria) during two growing seasons (2008 and 2009). Half-hourly flux values were calculated by means of the disjunct eddy covariance method using 3-dimensional wind-data of a sonic anemometer and mixing ratios of methanol measured with a proton-transfer-reaction-mass-spectrometer (PTR-MS). The surface conductance to water vapour was derived from measured evapotranspiration by inverting the Penman-Monteith combination equation (Wohlfahrt et al., 2009) for dry canopy conditions and used as a proxy for canopyscale stomatal conductance. Methanol fluxes exhibited a clear diurnal cycle with closetozero fluxes during nighttime and emissions, up to 10 nmol m-2 s-1, which followed the diurnal course of radiation and air temperature during daytime. Higher emissions of up to 30 nmol m-2 s-1were observed during cut events and spreading of organic manure. Methanol fluxes showed positive correlations with air temperature, stomatal conductance, and photosynthetically active radiation (PAR), confirming previous studies (e.g. Niinemets and Reichstein 2003). All three previously mentioned factors combined together were able to explain 40% of the observed flux variability. The influence of rapid changes in stomatal conductance on methanol fluxes, pointed out in earlier studies at the leaf-level (e.g. Niinemets and Reichstein 2003), could not be confirmed on ecosystem scale, possibly due to within-canopy gradients in stomatal conductance and the fact that fluxes were determined as half-hourly averages. As methanol is produced in expanding cell walls, the change in the measured green area index (?GAI) was used as a proxy for plant growth. However ?GAI was poorly correlated with methanol fluxes, possible explanations will be discussed. References: Davison, B., Brunner, A., Amman, C., Spirig, C., Jocher, M., Neftel, A. Cut-induced VOC emissions from agricultural grasslands. Plant Biol. 10, 76-85, 2008. Harley, P., Greenberg, J., Niinemets, Ü., and Guenther, A..: Environmental controls over methanol emission from leaves. Biogeosciences, 4, 1083-1099, 2007. Hüve, K., Christ, M., Kleist, E., Uerlings, R., Niinemets, Ü., Walter, A. and Wildt, J.: Simultaneous growth and emission measurements demonstrate an interactive control of methanol release by leaf expansion and stomata. doi:10.1093/jxb/erm038, Journal of Experimental Botany, 2007. Niinemets, Ü. and Reichstein, M.: Controls on the emission of plant volatiles through stomata: A sensitivity analysis. J. Geophys. Res., 108, 4211, doi:10.1029/2002JD002626, 2003. Niinemets, Ü., Loreto, F. and Reichstein, M.: Physiological and physicochemical controls on foliar volatile organic compound emissions. Trends in Plant Science,9, 2004. Wohlfahrt G., Haslwanter A., Hörtnagl L., Jasoni R.L., Fenstermaker L.F., Arnone J.A. III, Hammerle A. (2009) On the consequences of the energy imbalance for calculating surface conductance to water vapour. Agricultural and Forest Meteorology 149, 15561559.

Influence of Water Relations and Temperature on Leaf Movements of Rhododendron Species 1

PubMed Central

Nilsen, Erik Tallak

1987-01-01

Rhododendron maximum L. and R. Catawbiense L. are subcanopy evergreen shrubs of the eastern United States deciduous forest. Field measurements of climate factors and leaf movements of these species indicated a high correlation between leaf temperature and leaf curling; and between leaf water potential and leaf angle. Laboratory experiments were performed to isolate the influence of temperature and cellular water relations on leaf movements. Significant differences were found between the patterns of temperature induction of leaf curling in the two species. Leaves of the species which curled at higher temperatures (R. catawbiense) also froze at higher leaf temperatures. However, in both cases leaf curling occurred at leaf temperatures two to three degrees above the leaf freezing point. Pressure volume curves indicated that cellular turgor loss was associated with a maximum of 45% curling while 100% or more curling occurred in field leaves which still had positive cell turgor. Moisture release curves indicated that 70% curling requires a loss of greater than 60% of symplastic water which corresponds to leaf water potentials far below those experienced in field situations. Conversely, most laboratory induced changes in leaf angle could be related to leaf cell turgor loss. PMID:16665296

Maize YABBY genes drooping leaf1 and drooping leaf2 affect agronomic traits by regulating leaf architecture

USDA-ARS?s Scientific Manuscript database

Leaf architectural traits, such as length, width and angle, directly influence canopy structure and light penetration, photosynthate production and overall yield. We discovered and characterized a maize (Zea mays) mutant with aberrant leaf architecture we named drooping leaf1 (drl1), as leaf blades ...

7 CFR 29.1162 - Leaf (B Group).

Code of Federal Regulations, 2010 CFR

2010-01-01

... Specifications, and Tolerances B1L—Choice Quality Lemon Leaf Ripe, firm leaf structure, medium body, rich in oil... percent. B2L—Fine Quality Lemon Leaf Ripe, firm leaf structure, medium body, rich in oil, deep color.... B3L—Good Quality Lemon Leaf Ripe, firm leaf structure, medium body, oily, strong color intensity...

7 CFR 29.1162 - Leaf (B Group).

Code of Federal Regulations, 2011 CFR

2011-01-01

... Specifications, and Tolerances B1L—Choice Quality Lemon Leaf Ripe, firm leaf structure, medium body, rich in oil... percent. B2L—Fine Quality Lemon Leaf Ripe, firm leaf structure, medium body, rich in oil, deep color.... B3L—Good Quality Lemon Leaf Ripe, firm leaf structure, medium body, oily, strong color intensity...

7 CFR 28.471 - Below Leaf Grade Cotton.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Below Leaf Grade Cotton. 28.471 Section 28.471... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Leaf Grade Cotton § 28.471 Below Leaf Grade Cotton. Below leaf grade cotton is American Upland cotton which is lower in leaf grade than Leaf...

7 CFR 28.471 - Below Leaf Grade Cotton.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Below Leaf Grade Cotton. 28.471 Section 28.471... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Leaf Grade Cotton § 28.471 Below Leaf Grade Cotton. Below leaf grade cotton is American Upland cotton which is lower in leaf grade than Leaf...

7 CFR 28.471 - Below Leaf Grade Cotton.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Below Leaf Grade Cotton. 28.471 Section 28.471... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Leaf Grade Cotton § 28.471 Below Leaf Grade Cotton. Below leaf grade cotton is American Upland cotton which is lower in leaf grade than Leaf...

7 CFR 28.471 - Below Leaf Grade Cotton.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Below Leaf Grade Cotton. 28.471 Section 28.471... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Leaf Grade Cotton § 28.471 Below Leaf Grade Cotton. Below leaf grade cotton is American Upland cotton which is lower in leaf grade than Leaf...

7 CFR 28.471 - Below Leaf Grade Cotton.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Below Leaf Grade Cotton. 28.471 Section 28.471... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Leaf Grade Cotton § 28.471 Below Leaf Grade Cotton. Below leaf grade cotton is American Upland cotton which is lower in leaf grade than Leaf...

Ephemeroptera, Plecoptera and Trichoptera (Insecta) Abundance, Diversity and Role in Leaf Litter Breakdown in Tropical Headwater River

PubMed Central

Ab Hamid, Suhaila; Md Rawi, Che Salmah

2017-01-01

Leaf litter decomposition in a tropical stream was examined in two types of leaf packs; single species leaf packs of Pometia pinnata and two species leaf packs of equal combination of Pometia pinnata and Dolichandrone spathacea leaves. Both leaf packs were immersed in a river and weekly examined for remains of decomposed leaves and presence of EPT. In the control leaf packs, leaves in the two species leaf packs treatments decomposed within 35 days, faster than in single species leaf packs which decomposed after 42 days. In the presence of EPT, the leaf breakdown took 28 days in two species and 35 days for single species leaf packs. Higher abundance of EPT was observed in single species leaf packs but its diversity was higher in two species leaf packs. Litter breakdown in the stream was faster in the presence of EPT and softer leaves of D. spathacea with higher nitrogen content underwent faster decomposition and sustained higher numbers of EPT. PMID:28890763

Ephemeroptera, Plecoptera and Trichoptera (Insecta) Abundance, Diversity and Role in Leaf Litter Breakdown in Tropical Headwater River.

PubMed

Ab Hamid, Suhaila; Md Rawi, Che Salmah

2017-07-01

Leaf litter decomposition in a tropical stream was examined in two types of leaf packs; single species leaf packs of Pometia pinnata and two species leaf packs of equal combination of Pometia pinnata and Dolichandrone spathacea leaves. Both leaf packs were immersed in a river and weekly examined for remains of decomposed leaves and presence of EPT. In the control leaf packs, leaves in the two species leaf packs treatments decomposed within 35 days, faster than in single species leaf packs which decomposed after 42 days. In the presence of EPT, the leaf breakdown took 28 days in two species and 35 days for single species leaf packs. Higher abundance of EPT was observed in single species leaf packs but its diversity was higher in two species leaf packs. Litter breakdown in the stream was faster in the presence of EPT and softer leaves of D. spathacea with higher nitrogen content underwent faster decomposition and sustained higher numbers of EPT.

Leaf hydraulic conductance declines in coordination with photosynthesis, transpiration and leaf water status as soybean leaves age regardless of soil moisture

PubMed Central

Locke, Anna M.; Ort, Donald R.

2014-01-01

Photosynthesis requires sufficient water transport through leaves for stomata to remain open as water transpires from the leaf, allowing CO2 to diffuse into the leaf. The leaf water needs of soybean change over time because of large microenvironment changes over their lifespan, as leaves mature in full sun at the top of the canopy and then become progressively shaded by younger leaves developing above. Leaf hydraulic conductance (K leaf), a measure of the leaf’s water transport capacity, can often be linked to changes in microenvironment and transpiration demand. In this study, we tested the hypothesis that K leaf would decline in coordination with transpiration demand as soybean leaves matured and aged. Photosynthesis (A), stomatal conductance (g s) and leaf water potential (Ψleaf) were also measured at various leaf ages with both field- and chamber-grown soybeans to assess transpiration demand. K leaf was found to decrease as soybean leaves aged from maturity to shading to senescence, and this decrease was strongly correlated with midday A. Decreases in K leaf were further correlated with decreases in g s, although the relationship was not as strong as that with A. Separate experiments investigating the response of K leaf to drought demonstrated no acclimation of K leaf to drought conditions to protect against cavitation or loss of g s during drought and confirmed the effect of leaf age in K leaf observed in the field. These results suggest that the decline of leaf hydraulic conductance as leaves age keeps hydraulic supply in balance with demand without K leaf becoming limiting to transpiration water flux. PMID:25281701

Deer predation on leaf miners via leaf abscission

NASA Astrophysics Data System (ADS)

Yamazaki, Kazuo; Sugiura, Shinji

2008-03-01

The evergreen oak Quercus gilva Blume sheds leaves containing mines of the leaf miner Stigmella sp. (Lepidoptera: Nepticulidae) earlier than leaves with no mines in early spring in Nara, central Japan. The eclosion rates of the leaf miner in abscised and retained leaves were compared in the laboratory to clarify the effects of leaf abscission on leaf miner survival in the absence of deer. The leaf miner eclosed successfully from both fallen leaves and leaves retained on trees. However, sika deer ( Cervus nippon centralis Kishida) feed on the fallen mined leaves. Field observations showed that deer consume many fallen leaves under Q. gilva trees, suggesting considerable mortality of leaf miners due to deer predation via leaf abscission. This is a previously unreported relationship between a leaf miner and a mammalian herbivore via leaf abscission.

Expanding our understanding of leaf functional syndromes in savanna systems: the role of plant growth form.

PubMed

Rossatto, Davi Rodrigo; Franco, Augusto Cesar

2017-04-01

The assessment of leaf strategies has been a common theme in ecology, especially where multiple sources of environmental constraints (fire, seasonal drought, nutrient-poor soils) impose a strong selection pressure towards leaf functional diversity, leading to inevitable tradeoffs among leaf traits, and ultimately to niche segregation among coexisting species. As diversification on leaf functional strategies is dependent on integration at whole plant level, we hypothesized that regardless of phylogenetic relatedness, leaf trait functional syndromes in a multivariate space would be associated with the type of growth form. We measured traits related to leaf gas exchange, structure and nutrient status in 57 coexisting species encompassing all Angiosperms major clades, in a wide array of plant morphologies (trees, shrubs, sub-shrubs, herbs, grasses and palms) in a savanna of Central Brazil. Growth forms differed in mean values for the studied functional leaf traits. We extracted 4 groups of functional typologies: grasses (elevated leaf dark respiration, light-saturated photosynthesis on a leaf mass and area basis, lower values of leaf Ca and Mg), herbs (high values of SLA, leaf N and leaf Fe), palms (high values of stomatal conductance, leaf transpiration and leaf K) and woody eudicots (sub-shrubs, shrubs and trees; low SLA and high leaf Ca and Mg). Despite the large range of variation among species for each individual trait and the independent evolutionary trajectory of individual species, growth forms were strongly associated with particular leaf trait combinations, suggesting clear evolutionary constraints on leaf function for morphologically similar species in savanna ecosystems.

CO2 acclimation impacts leaf isoprene emissions: evidence from past to future CO2 levels

NASA Astrophysics Data System (ADS)

de Boer, Hugo; van der Laan, Annick; Dekker, Stefan; Holzinger, Rupert

2017-04-01

Isoprene is emitted by many plant species as a side-product of photosynthesis. Once in the atmosphere, isoprene exhibits climate forcing through various feedback mechanisms. In order to quantify the climate feedbacks of biogenic isoprene emission it is crucial to establish how isoprene emissions are effected by plant acclimation to rising atmospheric CO2 levels. A promising development for modelling CO2-induced changes in isoprene emissions is the Leaf-Energetic-Status model (referred to as LES-model hereafter, see Harrison et al., 2013 and Morfopoulos et al., 2014). This model simulates isoprene emissions based on the hypothesis that isoprene biosynthesis depends on the imbalance between the photosynthetic electron supply of reducing power and the electron demands of carbon fixation. The energetic imbalance is critically related to the photosynthetic electron transport capacity (Jmax) and the maximum carboxylation capacity of Rubisco (Vcmax). Here we compare predictions of the LES-model with observed isoprene emission responses of Quercus robur (pedunculate oak) specimen that acclimated to CO2 growth conditions representative of the last glacial, the present and the end of this century (200, 400 and 800 ppm, respectively) for two growing seasons. These plants were grown in walk-in growth chambers with tight control of light, temperature, humidity and CO2 concentrations. Photosynthetic biochemical parameters Vcmax and Jmax were determined with a Licor LI-6400XT photosynthesis system. The relationship between photosynthesis and isoprene emissions was measured by coupling the photosynthesis system with a Proton-Transfer Reaction Time-of-Flight Mass Spectrometer. Our empirical results support the LES-model and show that the fractional allocation of carbon to isoprene biosynthesis is reduced in response to both short-term and long-term CO2 increases. In the short term, an increase in CO2 stimulates photosynthesis through an increase in the leaf interior CO2 concentration and marginally decreases isoprene production owing to an increase in the electron demand for carbon fixation. In the long-term, acclimation to rising CO2 growth conditions leads to down regulation of both Jmax and Vcmax, which modulates the stimulating effect of rising CO2 on photosynthesis. This CO2 effect is most pronounced between sub-ambient to present CO2. Our results highlight that the LES-model provides a suitable theoretical framework to model changes in leaf isoprene emissions related to biochemical acclimation to rising CO2. References Harrison, S. P. et al: Volatile isoprenoid emissions from plastid to planet, New Phytol., 197(1), 49-57, 2013. Morfopoulos, C. et al: A model of plant isoprene emission based on available reducing power captures responses to atmospheric CO2, New Phytol., 203(1), 125-139, 2014.

Photoperiod-H1 (Ppd-H1) Controls Leaf Size1[OPEN

PubMed Central

Digel, Benedikt; Tavakol, Elahe; Verderio, Gabriele; Xu, Xin

2016-01-01

Leaf size is a major determinant of plant photosynthetic activity and biomass; however, it is poorly understood how leaf size is genetically controlled in cereal crop plants like barley (Hordeum vulgare). We conducted a genome-wide association scan for flowering time, leaf width, and leaf length in a diverse panel of European winter cultivars grown in the field and genotyped with a single-nucleotide polymorphism array. The genome-wide association scan identified PHOTOPERIOD-H1 (Ppd-H1) as a candidate gene underlying the major quantitative trait loci for flowering time and leaf size in the barley population. Microscopic phenotyping of three independent introgression lines confirmed the effect of Ppd-H1 on leaf size. Differences in the duration of leaf growth and consequent variation in leaf cell number were responsible for the leaf size differences between the Ppd-H1 variants. The Ppd-H1-dependent induction of the BARLEY MADS BOX genes BM3 and BM8 in the leaf correlated with reductions in leaf size and leaf number. Our results indicate that leaf size is controlled by the Ppd-H1- and photoperiod-dependent progression of plant development. The coordination of leaf growth with flowering may be part of a reproductive strategy to optimize resource allocation to the developing inflorescences and seeds. PMID:27457126

Leaf Phenological Characters of Main Tree Species in Urban Forest of Shenyang

PubMed Central

Xu, Sheng; Xu, Wenduo; Chen, Wei; He, Xingyuan; Huang, Yanqing; Wen, Hua

2014-01-01

Background Plant leaves, as the main photosynthetic organs and the high energy converters among primary producers in terrestrial ecosystems, have attracted significant research attention. Leaf lifespan is an adaptive characteristic formed by plants to obtain the maximum carbon in the long-term adaption process. It determines important functional and structural characteristics exhibited in the environmental adaptation of plants. However, the leaf lifespan and leaf characteristics of urban forests were not studied up to now. Methods By using statistic, linear regression methods and correlation analysis, leaf phenological characters of main tree species in urban forest of Shenyang were observed for five years to obtain the leafing phenology (including leafing start time, end time, and duration), defoliating phenology (including defoliation start time, end time, and duration), and the leaf lifespan of the main tree species. Moreover, the relationships between temperature and leafing phenology, defoliating phenology, and leaf lifespan were analyzed. Findings The timing of leafing differed greatly among species. The early leafing species would have relatively early end of leafing; the longer it took to the end of leafing would have a later time of completed leafing. The timing of defoliation among different species varied significantly, the early defoliation species would have relatively longer duration of defoliation. If the mean temperature rise for 1°C in spring, the time of leafing would experience 5 days earlier in spring. If the mean temperature decline for 1°C, the time of defoliation would experience 3 days delay in autumn. Interpretation There is significant correlation between leaf longevity and the time of leafing and defoliation. According to correlation analysis and regression analysis, there is significant correlation between temperature and leafing and defoliation phenology. Early leafing species would have a longer life span and consequently have advantage on carbon accumulation compared with later defoliation species. PMID:24963625

Comparison of dwarf bamboos (Indocalamus sp.) leaf parameters to determine relationship between spatial density of plants and total leaf area per plant.

PubMed

Shi, Pei-Jian; Xu, Qiang; Sandhu, Hardev S; Gielis, Johan; Ding, Yu-Long; Li, Hua-Rong; Dong, Xiao-Bo

2015-10-01

The relationship between spatial density and size of plants is an important topic in plant ecology. The self-thinning rule suggests a -3/2 power between average biomass and density or a -1/2 power between stand yield and density. However, the self-thinning rule based on total leaf area per plant and density of plants has been neglected presumably because of the lack of a method that can accurately estimate the total leaf area per plant. We aimed to find the relationship between spatial density of plants and total leaf area per plant. We also attempted to provide a novel model for accurately describing the leaf shape of bamboos. We proposed a simplified Gielis equation with only two parameters to describe the leaf shape of bamboos one model parameter represented the overall ratio of leaf width to leaf length. Using this method, we compared some leaf parameters (leaf shape, number of leaves per plant, ratio of total leaf weight to aboveground weight per plant, and total leaf area per plant) of four bamboo species of genus Indocalamus Nakai (I. pedalis (Keng) P.C. Keng, I. pumilus Q.H. Dai and C.F. Keng, I. barbatus McClure, and I. victorialis P.C. Keng). We also explored the possible correlation between spatial density and total leaf area per plant using log-linear regression. We found that the simplified Gielis equation fit the leaf shape of four bamboo species very well. Although all these four species belonged to the same genus, there were still significant differences in leaf shape. Significant differences also existed in leaf area per plant, ratio of leaf weight to aboveground weight per plant, and leaf length. In addition, we found that the total leaf area per plant decreased with increased spatial density. Therefore, we directly demonstrated the self-thinning rule to improve light interception.

Leaf anatomy mediates coordination of leaf hydraulic conductance and mesophyll conductance to CO2 in Oryza.

PubMed

Xiong, Dongliang; Flexas, Jaume; Yu, Tingting; Peng, Shaobing; Huang, Jianliang

2017-01-01

Leaf hydraulic conductance (K leaf ) and mesophyll conductance (g m ) both represent major constraints to photosynthetic rate (A), and previous studies have suggested that K leaf and g m is correlated in leaves. However, there is scarce empirical information about their correlation. In this study, K leaf , leaf hydraulic conductance inside xylem (K x ), leaf hydraulic conductance outside xylem (K ox ), A, stomatal conductance (g s ), g m , and anatomical and structural leaf traits in 11 Oryza genotypes were investigated to elucidate the correlation of H 2 O and CO 2 diffusion inside leaves. All of the leaf functional and anatomical traits varied significantly among genotypes. K leaf was not correlated with the maximum theoretical stomatal conductance calculated from stomatal dimensions (g smax ), and neither g s nor g smax were correlated with K x . Moreover, K ox was linearly correlated with g m and both were closely related to mesophyll structural traits. These results suggest that K leaf and g m are related to leaf anatomical and structural features, which may explain the mechanism for correlation between g m and K leaf . © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

7 CFR 29.3033 - Leaf.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Leaf. 29.3033 Section 29.3033 Agriculture Regulations... Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf. [49 FR 16758, Apr. 20, 1984] ...

7 CFR 29.3033 - Leaf.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Leaf. 29.3033 Section 29.3033 Agriculture Regulations... Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf. [49 FR 16758, Apr. 20, 1984] ...

7 CFR 29.3033 - Leaf.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Leaf. 29.3033 Section 29.3033 Agriculture Regulations... Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf. [49 FR 16758, Apr. 20, 1984] ...

7 CFR 29.3033 - Leaf.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Leaf. 29.3033 Section 29.3033 Agriculture Regulations... Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf. [49 FR 16758, Apr. 20, 1984] ...

7 CFR 29.3033 - Leaf.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf. 29.3033 Section 29.3033 Agriculture Regulations... Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf. [49 FR 16758, Apr. 20, 1984] ...

Relationships of leaf dark respiration to leaf nitrogen, specific leaf area and leaf life-span: a test across biomes and functional groups.

PubMed

Reich, Peter B; Walters, Michael B; Ellsworth, David S; Vose, James M; Volin, John C; Gresham, Charles; Bowman, William D

1998-05-01

Based on prior evidence of coordinated multiple leaf trait scaling, we hypothesized that variation among species in leaf dark respiration rate (R d ) should scale with variation in traits such as leaf nitrogen (N), leaf life-span, specific leaf area (SLA), and net photosynthetic capacity (A max ). However, it is not known whether such scaling, if it exists, is similar among disparate biomes and plant functional types. We tested this idea by examining the interspecific relationships between R d measured at a standard temperature and leaf life-span, N, SLA and A max for 69 species from four functional groups (forbs, broad-leafed trees and shrubs, and needle-leafed conifers) in six biomes traversing the Americas: alpine tundra/subalpine forest, Colorado; cold temperate forest/grassland, Wisconsin; cool temperate forest, North Carolina; desert/shrubland, New Mexico; subtropical forest, South Carolina; and tropical rain forest, Amazonas, Venezuela. Area-based R d was positively related to area-based leaf N within functional groups and for all species pooled, but not when comparing among species within any site. At all sites, mass-based R d (R d-mass ) decreased sharply with increasing leaf life-span and was positively related to SLA and mass-based A max and leaf N (leaf N mass ). These intra-biome relationships were similar in shape and slope among sites, where in each case we compared species belonging to different plant functional groups. Significant R d-mass -N mass relationships were observed in all functional groups (pooled across sites), but the relationships differed, with higher R d at any given leaf N in functional groups (such as forbs) with higher SLA and shorter leaf life-span. Regardless of biome or functional group, R d-mass was well predicted by all combinations of leaf life-span, N mass and/or SLA (r 2 ≥ 0.79, P < 0.0001). At any given SLA, R d-mass rises with increasing N mass and/or decreasing leaf life-span; and at any level of N mass , R d-mass rises with increasing SLA and/or decreasing leaf life-span. The relationships between R d and leaf traits observed in this study support the idea of a global set of predictable interrelationships between key leaf morphological, chemical and metabolic traits.

Food odors trigger Drosophila males to deposit a pheromone that guides aggregation and female oviposition decisions

PubMed Central

Lin, Chun-Chieh; Prokop-Prigge, Katharine A; Preti, George; Potter, Christopher J

2015-01-01

Animals use olfactory cues for navigating complex environments. Food odors in particular provide crucial information regarding potential foraging sites. Many behaviors occur at food sites, yet how food odors regulate such behaviors at these sites is unclear. Using Drosophila melanogaster as an animal model, we found that males deposit the pheromone 9-tricosene upon stimulation with the food-odor apple cider vinegar. This pheromone acts as a potent aggregation pheromone and as an oviposition guidance cue for females. We use genetic, molecular, electrophysiological, and behavioral approaches to show that 9-tricosene activates antennal basiconic Or7a receptors, a receptor activated by many alcohols and aldehydes such as the green leaf volatile E2-hexenal. We demonstrate that loss of Or7a positive neurons or the Or7a receptor abolishes aggregation behavior and oviposition site-selection towards 9-tricosene and E2-hexenal. 9-Tricosene thus functions via Or7a to link food-odor perception with aggregation and egg-laying decisions. DOI: http://dx.doi.org/10.7554/eLife.08688.001 PMID:26422512

``Low-cost Electronic nose evaluated on Thai-herb of Northern-Thailand samples using multivariate analysis methods''

NASA Astrophysics Data System (ADS)

na ayudhaya, Paisarn Daungjak; Klinbumrung, Arrak; Jaroensutasinee, Krisanadej; Pratontep, Sirapat; Kerdcharoen, Teerakiat

2009-05-01

In case of species of natural and aromatic plant originated from the northern Thailand, sensory characteristics, especially odours, have unique identifiers of herbs. The instruments sensory analysis have performed by several of differential of sensing, so call `electronic nose', to be a significantly and rapidly for chemometrics. The signal responses of the low cost electronic nose were evaluated by principal component analysis (PCA). The aims of this paper evaluated various of Thai-herbs grown in Northern of Thailand as data preprocessing tools of the Low-cost electronic nose (enNU-PYO1). The essential oil groups of Thai herbs such as Garlic, Lemongrass, Shallot (potato onion), Onion, Zanthoxylum limonella (Dennst.) Alston (Thai name is Makaen), and Kaffir lime leaf were compared volatilized from selected fresh herbs. Principal component analysis of the original sensor responses did clearly distinguish either all samples. In all cases more than 97% for cross-validated group were classified correctly. The results demonstrated that it was possible to develop in a model to construct a low-cost electronic nose to provide measurement of odoriferous herbs.

Fungicidal activity of essential oils of Cinnamomum zeylanicum (L.) and Syzygium aromaticum (L.) Merr et L.M. Perry against crown rot and anthracnose pathogens isolated from banana.

PubMed

Ranasinghe, L; Jayawardena, B; Abeywickrama, K

2002-01-01

To develop a post-harvest treatment system against post-harvest fungal pathogens of banana using natural products. Colletotrichum musae was isolated and identified as the causative agent responsible for anthracnose peel blemishes while three fungi, namely Lasiodiplodia theobromae, C. musae and Fusarium proliferatum, were identified as causative agents responsible for crown rot. During the liquid bioassay, cinnamon [Cinnamomum zeylanicum (L.)] leaf, bark and clove [Syzygium aromaticum (L.)] oils were tested against the anthracnose and crown rot pathogens. The test oils were fungistatic and fungicidal against the test pathogens within a range of 0.03-0.11% (v/v). Cinnamon and clove essential oils could be used as antifungal agents to manage post harvest fungal diseases of banana. Cinnamon and clove essential oil could be used as alternative post-harvest treatments on banana. Banana treated with essential oil is chemically safe and acceptable to consumers. Benomyl (Benlate), which is currently used to manage fungal pathogens, can cause adverse health effects and could be replaced with volatile essential oils.

7 CFR 29.3525 - Leaf.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Leaf. 29.3525 Section 29.3525 Agriculture Regulations... Type 95) § 29.3525 Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf. [49 FR 16759, Apr. 20, 1984] ...

7 CFR 29.3525 - Leaf.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Leaf. 29.3525 Section 29.3525 Agriculture Regulations... Type 95) § 29.3525 Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf. [49 FR 16759, Apr. 20, 1984] ...

7 CFR 29.3525 - Leaf.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Leaf. 29.3525 Section 29.3525 Agriculture Regulations... Type 95) § 29.3525 Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf. [49 FR 16759, Apr. 20, 1984] ...

7 CFR 29.3525 - Leaf.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf. 29.3525 Section 29.3525 Agriculture Regulations... Type 95) § 29.3525 Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf. [49 FR 16759, Apr. 20, 1984] ...

7 CFR 29.3525 - Leaf.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Leaf. 29.3525 Section 29.3525 Agriculture Regulations... Type 95) § 29.3525 Leaf. Whole, unstemmed leaf. Leaf, when applied to tobacco in strip form, shall describe the divided unit of a whole leaf. [49 FR 16759, Apr. 20, 1984] ...

Photoperiod-H1 (Ppd-H1) Controls Leaf Size.

PubMed

Digel, Benedikt; Tavakol, Elahe; Verderio, Gabriele; Tondelli, Alessandro; Xu, Xin; Cattivelli, Luigi; Rossini, Laura; von Korff, Maria

2016-09-01

Leaf size is a major determinant of plant photosynthetic activity and biomass; however, it is poorly understood how leaf size is genetically controlled in cereal crop plants like barley (Hordeum vulgare). We conducted a genome-wide association scan for flowering time, leaf width, and leaf length in a diverse panel of European winter cultivars grown in the field and genotyped with a single-nucleotide polymorphism array. The genome-wide association scan identified PHOTOPERIOD-H1 (Ppd-H1) as a candidate gene underlying the major quantitative trait loci for flowering time and leaf size in the barley population. Microscopic phenotyping of three independent introgression lines confirmed the effect of Ppd-H1 on leaf size. Differences in the duration of leaf growth and consequent variation in leaf cell number were responsible for the leaf size differences between the Ppd-H1 variants. The Ppd-H1-dependent induction of the BARLEY MADS BOX genes BM3 and BM8 in the leaf correlated with reductions in leaf size and leaf number. Our results indicate that leaf size is controlled by the Ppd-H1- and photoperiod-dependent progression of plant development. The coordination of leaf growth with flowering may be part of a reproductive strategy to optimize resource allocation to the developing inflorescences and seeds. © 2016 American Society of Plant Biologists. All rights reserved.