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1

Fungal assemblages associated with roots of halophytic and non-halophytic plant species vary differentially along a salinity gradient.  

PubMed

Structure of fungal communities is known to be influenced by host plants and environmental conditions. However, in most cases, the dynamics of these variation patterns are poorly understood. In this work, we compared richness, diversity, and composition between assemblages of endophytic and rhizospheric fungi associated to roots of two plants with different lifestyles: the halophyte Inula crithmoides and the non-halophyte I. viscosa (syn. Dittrichia viscosa L.), along a spatially short salinity gradient. Roots and rhizospheric soil from these plants were collected at three points between a salt marsh and a sand dune, and fungi were isolated and characterized by ITS rDNA sequencing. Isolates were classified in a total of 90 operational taxonomic units (OTUs), belonging to 17 fungal orders within Ascomycota and Basidiomycota. Species composition of endophytic and soil communities significantly differed across samples. Endophyte communities of I. crithmoides and I. viscosa were only similar in the intermediate zone between the salt marsh and the dune, and while the latter displayed a single, generalist association of endophytes, I. crithmoides harbored different assemblages along the gradient, adapted to the specific soil conditions. In the lower salt marsh, root assemblages were strongly dominated by a single dark septate sterile fungus, also prevalent in other neighboring salt marshes. Interestingly, although its occurrence was positively correlated to soil salinity, in vitro assays revealed a strong inhibition of its growth by salts. Our results suggest that host lifestyle and soil characteristics have a strong effect on endophytic fungi and that environmental stress may entail tight plant-fungus relationships for adaptation to unfavorable conditions. PMID:22573239

Maciá-Vicente, Jose G; Ferraro, Valeria; Burruano, Santella; Lopez-Llorca, Luis V

2012-10-01

2

Radical scavenging, antioxidant and antimicrobial activities of halophytic species Laetitia Meot-Durosa*  

E-print Network

Radical scavenging, antioxidant and antimicrobial activities of halophytic species Laetitia Meot-11Jan2011 #12;scavenging activity (Ksouri et al., 2006), but no antimicrobial properties have been investigations on in vitro antibacterial, radical scavenging and antioxidant activities of the extracts

Paris-Sud XI, Université de

3

ELECTROSTATIC CHANGES IN ROOT PLASMA MEMBRANE OF GLYCOPHYTIC AND HALOPHYTIC SPECIES OF TOMATO  

Technology Transfer Automated Retrieval System (TEKTRAN)

We investigated the effect of salt stress on the electrostatic properties of plasma membrane vesicles from the glycophytic tomato, Lycopersicon esculentum (Mill, cfs Heinz 1350 and VF 36) and the halophytic, wild species, L. cheesmanii (Hook, C.H. Mull, ecotype 1401) grown under control and saline c...

4

A spatial pattern analysis of the halophytic species distribution in an arid coastal environment.  

PubMed

Obtaining information about the spatial distribution of desert plants is considered as a serious challenge for ecologists and environmental modeling due to the required intensive field work and infrastructures in harsh and remote arid environments. A new method was applied for assessing the spatial distribution of the halophytic species (HS) in an arid coastal environment. This method was based on the object-based image analysis for a high-resolution Google Earth satellite image. The integration of the image processing techniques and field work provided accurate information about the spatial distribution of HS. The extracted objects were based on assumptions that explained the plant-pixel relationship. Three different types of digital image processing techniques were implemented and validated to obtain an accurate HS spatial distribution. A total of 2703 individuals of the HS community were found in the case study, and approximately 82 % were located above an elevation of 2 m. The micro-topography exhibited a significant negative relationship with pH and EC (r?=?-0.79 and -0.81, respectively, p?

Badreldin, Nasem; Uria-Diez, J; Mateu, J; Youssef, Ali; Stal, Cornelis; El-Bana, Magdy; Magdy, Ahmed; Goossens, Rudi

2015-05-01

5

Sulphide tolerance in coastal halophytes  

Microsoft Academic Search

The effect of sulphide on the growth of several species of salt-marsh plants was investigated. Relative growth rates were significantly reduced in two upper-marsh species, Festuca rubra and Atriplex patula, and in the lower-marsh species Puccinellia maritima. However the growth of Salicornia europaea, a species frequently associated with sulphide-containing sediments, was unaffected. In a separate experiment the wide ranging halophyte

D. C. Havill; A. Ingold; J. Pearson

1985-01-01

6

Influence of halophytic hosts on their parasites-the case of Plicosepalus acaciae.  

PubMed

Halophytes develop various morphological and physiological traits that enable them to grow successfully on saline substrates. Parasitic plants on halophytic hosts may also encounter salt stress. We investigated the mistletoe Plicosepalus acaciae (syn: Loranthus acacia; Loranthaceae), which occurs on 5 halophytic and at least 10 non-halophytic hosts in the Southern Arava Valley (Israel). Plicosepalus acaciae is a common parasite north of Eilat to the Dead Sea area and in the Jordan Valley. Morphological and physiological responses of P. acaciae to salinity were investigated by comparison of plants on halophytic with those on non-halophytic hosts. Ion patterns of different host-parasite associations were determined as was the development of leaf succulence at different growth stages. The leaf water content of P. acaciae increased and leaves developed succulence when growing on halophytic hosts, especially on Tamarix species, where leaf water content was three times higher than that on non-halophytic hosts and the leaf volume increased four to five times. The reason for increased succulence was a higher ion concentration of, and osmotic adjustment with, Na(+) and Cl(-). Plicosepalus acaciae showed a high morphological and ecophysiological plasticity, enabling it to cope with salt stress, and can be classified as a facultative eu-halophyte, which increases its halo-succulence according to the host. Host-parasite associations are a model system for the investigation of halophytes under different salt stress conditions. PMID:25515726

Veste, Maik; Todt, Henning; Breckle, Siegmar-W

2014-01-01

7

Stable hydrogen-isotope analysis of methyl chloride emitted from heated halophytic plants  

NASA Astrophysics Data System (ADS)

Stable isotope techniques are increasingly applied to study atmospheric budgets of methyl halides. Here we use compound specific thermal conversion isotope ratio mass spectrometry to measure the stable hydrogen isotope values of methyl chloride (?HCl) released thermally from dried leaves of halophyte plants collected from different geographical locations. We developed an automated purification and pre-concentration unit to enable measurement of ?HCl from samples (100 ml) when mixing ratios were as low as 1 ppmv. Even though this is considerably higher than normal atmospheric mixing ratios this unit enabled measurement of the ?2H values of CH3Cl released during heating of samples at temperatures ranging from 30 to 300 °C. No substantial changes of ?HCl values were observed over this temperature range. However, the ?HCl values of all plants examined were strongly depleted (-178 ± 34‰) relative to the ?2H values of their modelled meteoric water, but differ only by 1-50‰ from those observed for their methoxyl groups. Our results indicate that plant methoxyl groups are an important precursor of the methyl group for CH3Cl thermally emitted from lyophilised and homogenized dry halophyte leaves. Furthermore, the thermal reaction producing CH3Cl did not show a substantial kinetic hydrogen isotope fractionation between CH3Cl and precursor methoxyl groups over the temperature range investigated. Moreover, we found a moderate linear correlation (R2 = 0.37) for the relationship between ?HCl values released from halophytes and the ?2H values of modelled precipitation at their geographical locations. As CH3Cl emissions from terrestrial vegetation, including senescent and dry plants and biomass burning, are considered to provide a substantial fraction of the global emissions our findings are important when establishing a global hydrogen isotope model for atmospheric CH3Cl.

Greule, Markus; Huber, Stefan G.; Keppler, Frank

2012-12-01

8

Differential Activity of Plasma and Vacuolar Membrane Transporters Contributes to Genotypic Differences in Salinity Tolerance in a Halophyte Species, Chenopodium quinoa  

PubMed Central

Halophytes species can be used as a highly convenient model system to reveal key ionic and molecular mechanisms that confer salinity tolerance in plants. Earlier, we reported that quinoa (Chenopodium quinoa Willd.), a facultative C3 halophyte species, can efficiently control the activity of slow (SV) and fast (FV) tonoplast channels to match specific growth conditions by ensuring that most of accumulated Na+ is safely locked in the vacuole (Bonales-Alatorre et al. (2013) Plant Physiology). This work extends these finding by comparing the properties of tonoplast FV and SV channels in two quinoa genotypes contrasting in their salinity tolerance. The work is complemented by studies of the kinetics of net ion fluxes across the plasma membrane of quinoa leaf mesophyll tissue. Our results suggest that multiple mechanisms contribute towards genotypic differences in salinity tolerance in quinoa. These include: (i) a higher rate of Na+ exclusion from leaf mesophyll; (ii) maintenance of low cytosolic Na+ levels; (iii) better K+ retention in the leaf mesophyll; (iv) a high rate of H+ pumping, which increases the ability of mesophyll cells to restore their membrane potential; and (v) the ability to reduce the activity of SV and FV channels under saline conditions. These mechanisms appear to be highly orchestrated, thus enabling the remarkable overall salinity tolerance of quinoa species. PMID:23629664

Bonales-Alatorre, Edgar; Pottosin, Igor; Shabala, Lana; Chen, Zhong-Hua; Zeng, Fanrong; Jacobsen, Sven-Erik; Shabala, Sergey

2013-01-01

9

EFFECT OF SOIL SALINITY ON THE LIPID COMPOSITION OF HALOPHYTE PLANTS FROM THE SAND BAR OF POMORIE  

Microsoft Academic Search

Summary. Seven samples of halophyte plants (Bassia hirsuta Aschers, Euphorbia peplis L., Salicornia europeae L., Calystegia soldanella, Calystegia sepium, Stachys maritima Gonan and Suaeda maritima Dumort,) were collected from a sand bar near the town of Pomorie (Bulgaria). The soil salinity ranged between 650 and 850 mg salts in 100 g soil. For com- parison, two other samples from the

A. Ivanova; J. Nechev; K. Stefanov

2006-01-01

10

Effects of plant growth regulators and l -glutamic acid on shoot organogenesis in the halophyte Leymus chinensis (Trin.)  

Microsoft Academic Search

The halophyte Leymus chinensis (Trin.) is a perennial rhizome grass (tribe Gramineae) that is widely distributed in China, Mongolia and Siberia, where it\\u000a is produced as a forage product. In this report, we establish a highly reproducible plant regeneration system through somatic\\u000a embryogenesis. Two explants, mature seeds and leaf base segments were used; these parts displayed different responses to combinations

Yan-Lin Sun; Soon-Kwan Hong

2010-01-01

11

NaCl alleviates polyethylene glycol-induced water stress in the halophyte species Atriplex halimus L.  

PubMed

Atriplex halimus L. is a C4 xero-halophyte species well adapted to salt and drought conditions. To collect information on the physiological impact of low salt levels on their water-stress resistance, seedlings were exposed for 6 d to nutrient solution containing either 0% or 15% polyethylene glycol 10,000 (PEG), in the presence or in the absence of 50 mM NaCl. Similar experiments were performed with one PEG-resistant and one PEG-sensitive selected cell line exposed for 50 d to 0% or 15% PEG on standard Linsmaier and Skoog (LS) medium, on LS medium supplemented with 50 mM NaCl, or on Na+-free medium. NaCl mitigated the deleterious impact of PEG on growth of both whole plants and PEG-sensitive cell lines and improved the ability of stressed tissues to perform osmotic adjustment (OA). Water stress reduced CO2 net assimilation rates quantified in the presence of high CO2 and low O2 levels (A), stomatal conductance and transpiration, but NaCl improved water use efficiency of PEG-treated plants through its positive effect on A values, especially in young leaves. PEG increased the internal Na+ concentration. The resistant cell line accumulated higher concentration of Na+ than the PEG-sensitive one. The complete absence of Na+ in the medium endangered the survival of both cell lines exposed to PEG. Although Na+ by itself contributed only for a small part to OA, NaCl induced an increase in proline concentration and stimulated the synthesis of glycinebetaine in response to PEG in photosynthetic tissues. Soluble sugars were the main contributors to OA and increased when tissues were simultaneously exposed to PEG and NaCl compared with PEG alone, suggesting that Na+ may influence sugar synthesis and/or translocation. PMID:16043453

Martínez, Juan-Pablo; Kinet, Jean-Marie; Bajji, Mohammed; Lutts, Stanley

2005-09-01

12

Isolation of plant-growth-promoting rhizobacteria from rhizospheric soil of halophytes and their impact on maize (Zea mays L.) under induced soil salinity.  

PubMed

The present investigation was aimed to scrutinize the salt tolerance potential of plant-growth-promoting rhizobacteria (PGPR) isolated from rhizospheric soil of selected halophytes (Atriplex leucoclada, Haloxylon salicornicum, Lespedeza bicolor, Suaeda fruticosa, and Salicornica virginica) collected from high-saline fields (electrical conductivity 4.3-5.5) of District Mardan, Pakistan. Five PGPR strains were identified using 16S rRNA amplification and sequence analysis. Bacillus sp., isolated from rhizospheric soil of Atriplex leucoclada, and Arthrobacter pascens, isolated from rhizospheric soil of Suaeda fruticosa, are active phosphate solubilizers and bacteriocin and siderophore producers; hence, their inoculation and co-inoculation on maize ('Rakaposhi') under induced salinity stress enhanced shoot and root length and shoot and root fresh and dry mass. The accumulation of osmolytes, including sugar and proline, and the elevation of antioxidant enzymes activity, including superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase, were enhanced in the maize variety when inoculated and co-inoculated with Bacillus sp. and Arthrobacter pascens. The PGPR (Bacillus sp. and A. pascens) isolated from the rhizosphere of the mentioned halophytes species showed reliability in growth promotion of maize crop in all the physiological parameters; hence, they can be used as bio-inoculants for the plants growing under salt stress. PMID:25776270

Ullah, Sami; Bano, Asghari

2015-04-01

13

Adaptive Mechanisms of Halophytes in Desert Regions  

Microsoft Academic Search

Plants growing in desert regions have to face a number of environmental adversaries such as high temperature, soil salinity\\u000a and water stress due to low precipitation. Halophytes are among the successful plants that grow in desert saline regions.\\u000a Halophytes use many different strategies to survive under these conditions. Some halophytes seeds can germinate in the presence\\u000a of high salinity. Seeds

D. J. Weber

14

Seasonal effect of three desert halophytes on soil microbial functional diversity  

Microsoft Academic Search

The objective of this study was to evaluate the effect of some plant ecophysiological adaptations on soil microbial functional\\u000a diversity in a Negev Desert ecosystem. Soil samples from the upper 0–10 cm layer were collected at the study site under three\\u000a species of halophyte shrubs, Zygophyllum dumosum, Hammada scoparia, and Reaumuria negevensis. These halophytes represent the most typical cover of

Pinhasi-adiv Yocheved; Steinberger Yosef

2009-01-01

15

Potential Use of Halophytes to Remediate Saline Soils  

PubMed Central

Salinity is one of the rising problems causing tremendous yield losses in many regions of the world especially in arid and semiarid regions. To maximize crop productivity, these areas should be brought under utilization where there are options for removing salinity or using the salt-tolerant crops. Use of salt-tolerant crops does not remove the salt and hence halophytes that have capacity to accumulate and exclude the salt can be an effective way. Methods for salt removal include agronomic practices or phytoremediation. The first is cost- and labor-intensive and needs some developmental strategies for implication; on the contrary, the phytoremediation by halophyte is more suitable as it can be executed very easily without those problems. Several halophyte species including grasses, shrubs, and trees can remove the salt from different kinds of salt-affected problematic soils through salt excluding, excreting, or accumulating by their morphological, anatomical, physiological adaptation in their organelle level and cellular level. Exploiting halophytes for reducing salinity can be good sources for meeting the basic needs of people in salt-affected areas as well. This review focuses on the special adaptive features of halophytic plants under saline condition and the possible ways to utilize these plants to remediate salinity. PMID:25110683

Hasanuzzaman, Mirza; Nahar, Kamrun; Alam, Md. Mahabub; Bhowmik, Prasanta C.; Hossain, Md. Amzad; Rahman, Motior M.; Prasad, Majeti Narasimha Vara; Ozturk, Munir; Fujita, Masayuki

2014-01-01

16

Potential use of halophytes to remediate saline soils.  

PubMed

Salinity is one of the rising problems causing tremendous yield losses in many regions of the world especially in arid and semiarid regions. To maximize crop productivity, these areas should be brought under utilization where there are options for removing salinity or using the salt-tolerant crops. Use of salt-tolerant crops does not remove the salt and hence halophytes that have capacity to accumulate and exclude the salt can be an effective way. Methods for salt removal include agronomic practices or phytoremediation. The first is cost- and labor-intensive and needs some developmental strategies for implication; on the contrary, the phytoremediation by halophyte is more suitable as it can be executed very easily without those problems. Several halophyte species including grasses, shrubs, and trees can remove the salt from different kinds of salt-affected problematic soils through salt excluding, excreting, or accumulating by their morphological, anatomical, physiological adaptation in their organelle level and cellular level. Exploiting halophytes for reducing salinity can be good sources for meeting the basic needs of people in salt-affected areas as well. This review focuses on the special adaptive features of halophytic plants under saline condition and the possible ways to utilize these plants to remediate salinity. PMID:25110683

Hasanuzzaman, Mirza; Nahar, Kamrun; Alam, Md Mahabub; Bhowmik, Prasanta C; Hossain, Md Amzad; Rahman, Motior M; Prasad, Majeti Narasimha Vara; Ozturk, Munir; Fujita, Masayuki

2014-01-01

17

On the halophytic nature of mangroves  

USGS Publications Warehouse

Scientists have discussed the halophytic nature of intertidal plants for decades, and have generally suggested that inherent differentiation of an obligate halophyte from a facultative halophyte relates strongly to whether the plant can survive in fresh water, and not much else. In this mini-review, we provide additional insight to support the pervasive notion that mangroves as a group are truly facultative halophytes, and thus add discourse to the alternate view that mangroves have an obligate salinity requirement. Indeed, growth and physiological optima are realized at moderate salinity concentrations in mangroves, but we maintain the notion that current evidence suggests that survival is not dependent upon a physiological requirement for salt.

Krauss, Ken W.; Ball, Marilyn C.

2013-01-01

18

Coping with low nutrient availability and inundation: root growth responses of three halophytic grass species from different elevations along a flooding gradient  

Microsoft Academic Search

We describe the responses of three halophytic grass species that dominate the low (Spartina anglica), middle (Puccinellia maritima) and high (Elymus pycnanthus) parts of a salt marsh, to soil conditions that are believed to favour contrasting root-growth strategies. Our hypotheses were: (1) individual lateral root length is enhanced by N limitations in the soil but restricted by oxygen limitations, (2)

Tjeerd J. Bouma; Bas P. Koutstaal; Michel van Dongen; Kai L. Nielsen

2001-01-01

19

Enhanced salt stress tolerance of rice plants expressing a vacuolar H+-ATPase subunit c1 (SaVHAc1) gene from the halophyte grass Spartina alterniflora Löisel  

Technology Transfer Automated Retrieval System (TEKTRAN)

The physiological role of a vacuolar ATPase subunit c1 (SaVHAc1) from a halophyte grass Spartina alterniflora was studied through its expression in rice. The SaVHAc1– expressing plants showed enhanced tolerance to salt stress than the wild-type plants, mainly through adjustments in early stage and p...

20

RNA-Seq Analysis of the Response of the Halophyte, Mesembryanthemum crystallinum (Ice Plant) to High Salinity  

PubMed Central

Understanding the molecular mechanisms that convey salt tolerance in plants is a crucial issue for increasing crop yield. The ice plant (Mesembryanthemum crystallinum) is a halophyte that is capable of growing under high salt conditions. For example, the roots of ice plant seedlings continue to grow in 140 mM NaCl, a salt concentration that completely inhibits Arabidopsis thaliana root growth. Identifying the molecular mechanisms responsible for this high level of salt tolerance in a halophyte has the potential of revealing tolerance mechanisms that have been evolutionarily successful. In the present study, deep sequencing (RNAseq) was used to examine gene expression in ice plant roots treated with various concentrations of NaCl. Sequencing resulted in the identification of 53,516 contigs, 10,818 of which were orthologs of Arabidopsis genes. In addition to the expression analysis, a web-based ice plant database was constructed that allows broad public access to the data. The results obtained from an analysis of the RNAseq data were confirmed by RT-qPCR. Novel patterns of gene expression in response to high salinity within 24 hours were identified in the ice plant when the RNAseq data from the ice plant was compared to gene expression data obtained from Arabidopsis plants exposed to high salt. Although ABA responsive genes and a sodium transporter protein (HKT1), are up-regulated and down-regulated respectively in both Arabidopsis and the ice plant; peroxidase genes exhibit opposite responses. The results of this study provide an important first step towards analyzing environmental tolerance mechanisms in a non-model organism and provide a useful dataset for predicting novel gene functions. PMID:25706745

Tsukagoshi, Hironaka; Suzuki, Takamasa; Nishikawa, Kouki; Agarie, Sakae; Ishiguro, Sumie; Higashiyama, Tetsuya

2015-01-01

21

RNA-Seq Analysis of the Response of the Halophyte, Mesembryanthemum crystallinum (Ice Plant) to High Salinity.  

PubMed

Understanding the molecular mechanisms that convey salt tolerance in plants is a crucial issue for increasing crop yield. The ice plant (Mesembryanthemum crystallinum) is a halophyte that is capable of growing under high salt conditions. For example, the roots of ice plant seedlings continue to grow in 140 mM NaCl, a salt concentration that completely inhibits Arabidopsis thaliana root growth. Identifying the molecular mechanisms responsible for this high level of salt tolerance in a halophyte has the potential of revealing tolerance mechanisms that have been evolutionarily successful. In the present study, deep sequencing (RNAseq) was used to examine gene expression in ice plant roots treated with various concentrations of NaCl. Sequencing resulted in the identification of 53,516 contigs, 10,818 of which were orthologs of Arabidopsis genes. In addition to the expression analysis, a web-based ice plant database was constructed that allows broad public access to the data. The results obtained from an analysis of the RNAseq data were confirmed by RT-qPCR. Novel patterns of gene expression in response to high salinity within 24 hours were identified in the ice plant when the RNAseq data from the ice plant was compared to gene expression data obtained from Arabidopsis plants exposed to high salt. Although ABA responsive genes and a sodium transporter protein (HKT1), are up-regulated and down-regulated respectively in both Arabidopsis and the ice plant; peroxidase genes exhibit opposite responses. The results of this study provide an important first step towards analyzing environmental tolerance mechanisms in a non-model organism and provide a useful dataset for predicting novel gene functions. PMID:25706745

Tsukagoshi, Hironaka; Suzuki, Takamasa; Nishikawa, Kouki; Agarie, Sakae; Ishiguro, Sumie; Higashiyama, Tetsuya

2015-01-01

22

Potential uses of TerraSAR-X for mapping herbaceous halophytes over salt marsh and tidal flats  

NASA Astrophysics Data System (ADS)

This study presents a method and application results of mapping different halophytes over tidal flats and salt marshes using high resolution space-borne X-band synthetic aperture radar (SAR) that has been rarely used for salt marsh mapping. Halophytes in a salt marshes are sensitive to sea-level changes, sedimentation, and anthropogenic modifications. The alteration of the demarcations among halophyte species is an indicator of sea level and environmental changes within a salt marsh. The boundary of an herbaceous halophyte patch is, however, difficult to determine using remotely sensed data because of its sparseness. We examined the ecological status of the halophytes and their distribution changes using TerraSAR-X and optical data. We also determined the optimum season for halophyte mapping. An annual plant, Suaeda japonica (S. japonica), and a typical perennial salt marsh grass, Phragmites australis (P. australis), were selected for halophyte analysis. S. japonica is particularly sensitive to sea level fluctuation. Seasonal variation for the annual plant was more significant (1.47 dB standard deviation) than that for the perennial grass, with a pattern of lower backscattering in winter and a peak in the summer. The border between S. japonica and P. australis was successfully determined based on the distinctive X-band radar backscattering features. Winter is the best season to distinguish between the two different species, while summer is ideal for analyzing the distribution changes of annual plants in salt marshes. For a single polarization, we recommend using HH polarization, because it produces maximum backscattering on tidal flats and salt marshes. Our results show that high resolution SAR, such as TerraSAR-X and Cosmo-SkyMed, is an effective tool for mapping halophyte species in tidal flats and monitoring their seasonal variations.

Lee, Yoon-Kyung; Park, Jeong-Won; Choi, Jong-Kuk; Oh, Yisok; Won, Joong-Sun

2012-12-01

23

Maritime Halophyte Species from Southern Portugal as Sources of Bioactive Molecules  

PubMed Central

Extracts of five halophytes from southern Portugal (Arthrocnemum macrostachyum, Mesembryanthemum edule, Juncus acutus, Plantago coronopus and Halimione portulacoides), were studied for antioxidant, anti-inflammatory and in vitro antitumor properties. The most active extracts towards the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical were the methanol extracts of M. edule (IC50 = 0.1 mg/mL) and J. acutus (IC50 = 0.4 mg/mL), and the ether extracts of J. acutus (IC50 = 0.2 mg/mL) and A. macrostachyum (IC50 = 0.3 mg/mL). The highest radical scavenging activity (RSA) against the 2,2?-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical was obtained in the ether extract of J. acutus (IC50 = 0.4 mg/mL) and H. portulacoides (IC50 = 0.9 mg/mL). The maximum total phenolic content (TPC) was found in the methanol extract of M. edule (147 mg gallic acid equivalents (GAE)/g) and in the ether extract of J. acutus (94 mg GAE/g). Significant decreases in nitric oxide (NO) production were observed after incubation of macrophages with lipopolysaccharide (LPS) and the chloroform extract of H. portulacoides (IC50 = 109 µg/mL) and the hexane extract of P. coronopus (IC50 = 98.0 µg/mL). High in vitro cytotoxic activity and selectivity was obtained with the ether extract of J. acutus. Juncunol was identified as the active compound and for the first time was shown to display selective in vitro cytotoxicity towards various human cancer cells. PMID:24727393

Rodrigues, Maria João; Gangadhar, Katkam N.; Vizetto-Duarte, Catarina; Wubshet, Sileshi G.; Nyberg, Nils T.; Barreira, Luísa; Varela, João; Custódio, Luísa

2014-01-01

24

[Response characteristics of the field-measured spectrum for the four gerneral types of halophyte and species recognition in the northern slope area of Tianshan Mountain in Xinjiang].  

PubMed

Based on the field-measured Vis-NIR reflectance of four common types of halophyte (Achnatherum splendens(Trin.) Nevski, Sophora alopecuroides L., Camphorosma monspeliaca L. subsp. lessingii(L.)Aellen, Alhagi sparsifolia shap) within given spots in the Northern Slope Area of Tianshan Mountain in Xinjiang, the spectral response characteristics and species recognition of these types of halophyte were analyzed. The results showed that (Alhagi sparsifolia shap) had higher chlorophyll and carotenoid by CARI and SIPI index. (Sophora alopecuroides L. was at a vigorously growing state and had a higher NDVI compared with the other three types of halophyte because of its greater canopy density. But its CARI and SIPI values were lower due to the influence of its flowers. (Sophora alopecuroides L.) and (Camphorosma monspeliaca L. subsp. lessingii(L.)) had stable REPs and BEPs, but REPs and BEPs of (Achnatherum splendens(Trin.)Nevski, Aellen, Alhagi sparsifolia shap) whose spectra red shift and spectra blue shift occurred concurrently obviously changed. There was little difference in spectral curves among the four types of halophyte, so the spectrum mixing phenomenon was severe. (Camphorosma monspeliaca L. subsp. lessingii (L.)Aellen) and (Alhagi sparsifolia shap) could not be separated exactly in a usual R/NIR feature space in remote sensing. Using the stepwise discriminant analysis, five indices were selected to establish the discriminant model, and the model accuracy was discussed using the validated sample group. The total accuracy of the discriminant model was above 92% and (Achnatherum splendens(Trin.)Nevski) and (Camphorosma monspeliaca L. subsp. lessingii(L.)Aellen) could be respectively recognized 100% correctly. PMID:22295790

Zhang, Fang; Xiong, Hei-gang; Nurbay, Abdusalih; Luan, Fu-ming

2011-12-01

25

The roots of the halophyte Salicornia brachiata are a source of new halotolerant diazotrophic bacteria with plant growth-promoting potential  

Microsoft Academic Search

Soil salinity is the major cause limiting plant productivity worldwide. Nitrogen-fixing bacteria were enriched and characterised\\u000a from roots of Salicornia brachiata, an extreme halophyte which has substantial economic value as a bioresource of diverse and valuable products. Nitrogen-free\\u000a semisolid NFb medium with malate as carbon source and up to 4% NaCl were used for enrichment and isolation of diazotrophic\\u000a bacteria.

Bhavanath Jha; Iti Gontia; Anton Hartmann

26

Isolation and characterization of endophytic plant growth-promoting (PGPB) or stress homeostasis-regulating (PSHB) bacteria associated to the halophyte Prosopis strombulifera  

Microsoft Academic Search

This study was designed to isolate and characterize endophytic bacteria from halophyte Prosopis strombulifera grown under extreme salinity and to evaluate in vitro the bacterial mechanisms related to plant growth promotion or stress\\u000a homeostasis regulation. Isolates obtained from P. strombulifera were compared genotypically by BOX-polymerase chain reaction, grouped according to similarity, and identified by amplification\\u000a and partial sequences of 16S

Verónica Sgroy; Fabricio Cassán; Oscar Masciarelli; María Florencia Del Papa; Antonio Lagares; Virginia Luna

2009-01-01

27

Effects of Two Halophytic Plants (Kochia and Atriplex) on Digestibility, Fermentation and Protein Synthesis by Ruminal Microbes Maintained in Continuous Culture  

PubMed Central

Eight continuous culture fermenters were used in a completely randomized design to evaluate various nutritional values of Kochia (Kochia scoparia) compared with Atriplex (Atriplex dimorphostegia). Dried and pelleted samples (leaves and stems) provided substrate for metabolism by ruminal microbes maintained in a continuous culture fermentation system. Results indicated that there were no differences (p>0.05) in dry matter (DM) and crude protein (CP) digestibility between the two halophytic plants. Atriplex had higher (p<0.05) organic matter (OM) digestibility compared with Kochia. Neutral detergent fiber (aNDF) digestibility of Atriplex (411 g/kg) was higher (p<0.05) than that of Kochia (348 g/kg), however acid detergent fiber (ADF) digestibility was higher (p<0.05) in Kochia compared with Atriplex (406 vs. 234 g/kg). There were no differences (p>0.05) between the two halophytic plants in molar proportion of acetate and propionate, but the concentration of butyrate and valerate in Kochia were about two fold of Atriplex (p<0.05). When Kochia provided substrate to the microbes, protein synthesis was higher (p<0.05) compared with feeding Atriplex (5.96 vs. 4.85 g N/kg of OM truly digested). It was concluded that Kochia scoparia and Atriplex dimorphostegia had similar digestibility of DM and CP. It appears that these halophytic plants may not have enough digestible energy for high producing ruminants. PMID:25049608

Riasi, A.; Mesgaran, M. Danesh; Stern, M. D.; Ruiz Moreno, M. J.

2012-01-01

28

Collection and composition of xylem sap and root structure in two halophytic species  

Microsoft Academic Search

Leptochloa fusca (L.) Kunth and Atriplex hortensis (L.) were grown on quartz sand or in liquid culture in the presence of varied concentrations of NaCl. Xylem sap was collected as (a) root pressure exudate, in L. fusca even at 100 mM NaCl, (b) by applying pressure to excised roots of L. fusca and (c) from leaves of the whole plant

W. Dieter Jeschke; Sabine Klagges I; A. Saeed Bhatti

1995-01-01

29

HALOPHYTES—AN EMERGING TREND IN PHYTOREMEDIATION  

Microsoft Academic Search

Halophytic plants are of special interest since these plants are naturally present in environments characterized by an excess of toxic ions, mainly sodium and chloride. Several studies have revealed that these plants may also tolerate other stresses including heavy metals based on the findings that tolerance to salt and to heavy metals may, at least partly, rely on common physiological

Eleni Manousaki; Nicolas Kalogerakis

2011-01-01

30

An inland and a coastal population of the Mediterranean xero-halophyte species Atriplex halimus L. differ in their ability to accumulate proline and glycinebetaine in response to salinity and water stress.  

PubMed

Soil salinity and drought compromise water uptake and lead to osmotic adjustment in xero-halophyte plant species. These important environmental constraints may also have specific effects on plant physiology. Stress-induced accumulation of osmocompatible solutes was analysed in two Tunisian populations of the Mediteranean shrub Atriplex halimus L.-plants originating from a salt-affected coastal site (Monastir) or from a non-saline semi-arid area (Sbikha)-were exposed to nutrient solution containing either low (40 mM) or high (160 mM) doses of NaCl or 15% polyethylene glycol. The low NaCl dose stimulated plant growth in both populations. Plants from Monastir were more resistant to high salinity and exhibited a greater ability to produce glycinebetaine in response to salt stress. Conversely, plants from Sbikha were more resistant to water stress and displayed a higher rate of proline accumulation. Proline accumulated as early as 24 h after stress imposition and such accumulation was reversible. By contrast, glycinebetaine concentration culminated after 10 d of stress and did not decrease after the stress relief. The highest salt resistance of Monastir plants was not due to a lower rate of Na(+) absorption; plants from this population exhibited a higher stomatal conductance and a prodigal water-use strategy leading to lower water-use efficiency than plants from Sbikha. Exogenous application of proline (1 mM) improved the level of drought resistance in Monastir plants through a decrease in oxidative stress quantified by the malondialdehyde concentration, while the exogenous application of glycinebetaine improved the salinity resistance of Sbikha plants through a positive effect on photosystem II efficiency. PMID:18385490

Ben Hassine, Abir; Ghanem, Michel Edmond; Bouzid, Sadok; Lutts, Stanley

2008-01-01

31

Salt Stress Perception and Plant Growth Regulators in the Halophyte Mesembryanthemum crystallinum.  

PubMed Central

We selected indicators of four different metabolic processes (Crassulacean acid metabolism [CAM], amino acid and nitrogen mobilization metabolism, osmoprotection, and plant defense mechanisms) to study the relationship between salt-stress-mediated and plant growth regulator (PGR)-induced responses in Mesembryanthemum crystallinum (ice plant). Nacl and PGRs (cytokinin and abscisic acid [ABA]) are efficient elicitors of the well-studied Nacl stress responses: induction of the CAM form of phosphoenolpyruvate carboxylase, proline pinitol accumulation, and the increase of an osmotin-like protein. NaCl and cytokinin are more effective than ABA in stimulating accumulation of proline and an osmotin-like protein before the plants are committed to flowering. The results are consistent with a plant defense-induction model, in which environmental stress and PGRs are distinct signals whose subsequent effects lead to overlapping responses, the magnitude of which depends on plant developmental status. PMID:12232022

Thomas, J. C.; Bohnert, H. J.

1993-01-01

32

The role of proline accumulation in halophytes  

Microsoft Academic Search

It is shown that in the majority of higher plant halophytes examined proline is the major component of the amino acid pool in plants collected from the field. In Triglochin maritima L. free proline can represent 10–20% of the shoot dry weight. Under non-saline conditions proline levels are low and increase as the salinity is raised. Comparisons of inland and

G. R. Stewart; J. A. Lee

1974-01-01

33

Changes in cellular distribution regulate SKD1 ATPase activity in response to a sudden increase in environmental salinity in halophyte ice plant  

PubMed Central

Halophyte Mesembryanthemum crystallinum L. (ice plant) rapidly responds to sudden increases in salinity in its environment by activating specific salt-tolerant mechanisms. One major strategy is to regulate a series of ion transporters and proton pumps to maintain cellular Na+/K+ homeostasis. Plant SKD1 (suppressor of K+ transport growth defect 1) proteins accumulate in cells actively engaged in the secretory processes, and play a critical role in intracellular protein trafficking. Ice plant SKD1 redistributes from the cytosol to the plasma membrane hours after salt stressed. In combination with present knowledge of this protein, we suggest that stress facilitates SKD1 movement to the plasma membrane where ADP/ATP exchange occurs, and functions in the regulation of membrane components such as ion transporters to avoid ion toxicity. PMID:24390077

Jou, Yingtzy; Chiang, Chih-Pin; Yen, Hungchen Emilie

2013-01-01

34

Halophytes Energy Feedstocks: Back to Our Roots  

NASA Technical Reports Server (NTRS)

Of the Earth s landmass, approx.43% is arid or semi-arid, and 97% of the Earth s water is seawater. Halophytes are salt-tolerant plants (micro and macro) that can prosper in seawater or brackish waters and are common feedstocks for fuel and food (fuel-food feedstocks) in depressed countries. Two types, broadly classed as coastal and desert, can be found in marshes, coastal planes, inland lakes, and deserts. Major arid or semi-arid halophyte agriculture problems include pumping and draining the required high volumes of irrigation water from sea or ocean sources. Also, not all arid or semi-arid lands are suitable for crops. Benefits of halophyte agriculture include freeing up arable land and freshwater resources, cleansing the environment, decontaminating soils, desalinating brackish waters, and carbon sequestration. Sea and ocean halophyte agriculture problems include storms, transport, and diffuse harvesting. Benefits include available nutrients, ample water, and Sun. Careful attention to details and use of saline agriculture fuel feedstocks are required to prevent anthropogenic disasters. It is shown that the potential for fuel-food feedstock halophyte production is high; based on test plot data, it could supply 421.4 Quad, or 94% of the 2004 world energy consumption and sequester carbon, with major impact on the Triangle of Conflicts.

Hendricks, Robert C.; Bushnell, Dennis M.

2007-01-01

35

Mineral ion composition of halophytes and associated soils in Western Canada  

Microsoft Academic Search

The mineral ion contents of seven halophytic species in the family Chenopodiaceae, and associated soils were examined. Each species was found growing in soils with wide ranges of salinity, sodicity and salt ion composition. Absolute concentrations of Na, Ca, Mg, K, Cl and SO4 in shoot tissue differed significantly among species. Species were classified into two groups: (1) chloride halophytes,

R. E. Redmann; P. Fedec

1987-01-01

36

Habitat specificity of a threatened and endemic, cliff-dwelling halophyte  

PubMed Central

Coastal areas and other saline environments are major contributors to regional and global biodiversity patterns. In these environments, rapidly changing gradients require highly specialized plants like halophytes. In European coastal cliff-tops, rocky and sandy seashores, and saltmarshes, typical halophytes from the genus Limonium are commonly found. Among them, the aneuploid tetraploid (2n = 4x = 35, 36, 37) Limonium multiflorum, endemic to the west coast of Portugal, is an interesting case study for investigating the ecology and conservation of a halophyte agamospermic species. Although it is listed in the IUCN red list of threatened species, information on its population size or rarity, as well as its ecology, in some respects is still unknown. Field surveys in the largest known population were performed (Raso cape, Portugal) in order to determine habitat requirements and conservation status. A total of 88 quadrats were monitored, 43 of which contained at least one L. multiflorum individual. For each sampled quadrat, four abiotic and four biotic variables as well as two spatially derived variables were recorded. Principal component analysis and cluster analysis showed narrow habitat specificity for this species which appeared to be intolerant to competition with invasive alien plants. We conclude that in situ conservation in a local ‘hotspot’ of this rare and vulnerable species emerges as a priority in order to ensure that biodiversity is not lost. PMID:24942513

Caperta, Ana D.; Espírito-Santo, M. Dalila; Silva, Vasco; Ferreira, Ana; Paes, Ana P.; Róis, Ana S.; Costa, José C.; Arsénio, Pedro

2014-01-01

37

Habitat specificity of a threatened and endemic, cliff-dwelling halophyte.  

PubMed

Coastal areas and other saline environments are major contributors to regional and global biodiversity patterns. In these environments, rapidly changing gradients require highly specialized plants like halophytes. In European coastal cliff-tops, rocky and sandy seashores, and saltmarshes, typical halophytes from the genus Limonium are commonly found. Among them, the aneuploid tetraploid (2n = 4x = 35, 36, 37) Limonium multiflorum, endemic to the west coast of Portugal, is an interesting case study for investigating the ecology and conservation of a halophyte agamospermic species. Although it is listed in the IUCN red list of threatened species, information on its population size or rarity, as well as its ecology, in some respects is still unknown. Field surveys in the largest known population were performed (Raso cape, Portugal) in order to determine habitat requirements and conservation status. A total of 88 quadrats were monitored, 43 of which contained at least one L. multiflorum individual. For each sampled quadrat, four abiotic and four biotic variables as well as two spatially derived variables were recorded. Principal component analysis and cluster analysis showed narrow habitat specificity for this species which appeared to be intolerant to competition with invasive alien plants. We conclude that in situ conservation in a local 'hotspot' of this rare and vulnerable species emerges as a priority in order to ensure that biodiversity is not lost. PMID:24942513

Caperta, Ana D; Espírito-Santo, M Dalila; Silva, Vasco; Ferreira, Ana; Paes, Ana P; Róis, Ana S; Costa, José C; Arsénio, Pedro

2014-01-01

38

Comparative Proteomics of Thellungiella halophila Leaves from Plants Subjected to Salinity Reveals the Importance of Chloroplastic Starch and Soluble Sugars in Halophyte Salt Tolerance*  

PubMed Central

Thellungiella halophila, a close relative of Arabidopsis, is a model halophyte used to study plant salt tolerance. The proteomic/physiological/transcriptomic analyses of Thellungiella plant leaves subjected to different salinity levels, reported herein, indicate an extraordinary ability of Thellungiella to adapt to large concentrations of exogenous saline by compartmentalizing Na+ into cell vacuoles and accumulating proline and soluble sugars as organic osmolytes. Salinity stress stimulated the accumulation of starch in chloroplasts, which resulted in a greatly increased content of starch and total sugars in leaves. Comparative proteomics of Thellungiella leaves identified 209 salt-responsive proteins. Among these, the sequences of 108 proteins were strongly homologous to Arabidopsis protein sequences, and 30 had previously been identified as Thellungiella proteins. Functional classification of these proteins into 16 categories indicated that the majority are involved in carbohydrate metabolism, followed by those involved in energy production and conversion, and then those involved in the transport of inorganic ions. Pathway analysis revealed that most of the proteins are involved in starch and sucrose metabolism, carbon fixation, photosynthesis, and glycolysis. Of these processes, the most affected were starch and sucrose metabolism, which might be pivotal for salt tolerance. The gene expression patterns of the 209 salt-responsive proteins revealed through hierarchical clustering of microarray data and the expression patterns of 29 Thellungiella genes evaluated via quantitative RT-PCR were similar to those deduced via proteomic analysis, which underscored the possibility that starch and sucrose metabolism might play pivotal roles in determining the salt tolerance ability of Thellungiella. Our observations enabled us to propose a schematic representation of the systematic salt-tolerance phenotype in Thellungiella and suggested that the increased accumulation of starch, soluble sugars, and proline, as well as subcellular compartmentalization of sodium, might collectively denote important mechanisms for halophyte salt tolerance. PMID:23660471

Wang, Xuchu; Chang, Lili; Wang, Baichen; Wang, Dan; Li, Pinghua; Wang, Limin; Yi, Xiaoping; Huang, Qixing; Peng, Ming; Guo, Anping

2013-01-01

39

On the distribution and evaluation of Na, Mg and Cl in leaves of selected halophytes  

NASA Astrophysics Data System (ADS)

Diverse physiological, biochemical and morphological adaptations enable plants to survive in extreme saline environments where osmotic and ionic stresses limit growth and development. Halophytes are salt-tolerant plants that can withstand extraordinarily high levels of Na and Cl in their leaves. The tissue and cellular distribution patterns of salt ions can be linked to the underlying mechanisms of salt tolerance. Application of fast, reliable, multi-elemental and quantitative techniques such as micro-proton-induced X-ray emission (micro-PIXE) will significantly contribute to and accelerate studies of plant salt tolerance, especially as micro-PIXE also provides spatially resolved quantitative data for light elements, such as Na and Mg. The spatial concentration distributions of Na, Mg, Cl, K, P and S in leaves of four halophytes (Bassia indica, Atriplex prostrata, Spartina maritima and Limonium angustifolium) were determined using micro-PIXE, to study the salt-tolerance strategies of the selected halophytes. Different distribution patterns of the studied elements were seen in the leaves; however, in all four of these plant species, Na was excluded from photosynthetically active chlorophyl tissues. With the exception of L. angustifolium, Cl, P and S contents (representing chloride, phosphate and sulphate ionic forms, respectively) did not ensure charge balance in the leaves, which suggests other anionic compounds, such as nitrate and organic anions, have crucial roles in maintaining electroneutrality in these halophytes. By increasing soil salinisation worldwide, the possibility to reliably complement spatial distributions of Na, Mg, Cl, K, P and S with plant structural morphology will contribute significantly to our understanding of plant tolerance mechanisms at the tissue and cell levels. In addition, these kinds of studies are of particular value for designing crop plants with high salt tolerance and for the development of phytoremediation technologies.

Pongrac, Paula; Vogel-Mikuš, Katarina; Regvar, Marjana; Kaligari?, Mitja; Vavpeti?, Primož; Kelemen, Mitja; Grlj, Nataša; Shelef, Oren; Golan-Goldhirsh, Avi; Rachmilevitch, Shimon; Pelicon, Primož

2013-07-01

40

Conveyor Cultivation of the Halophytic Plant Salicornia europaea for the Recycling of NaCl from Human Liquid Waste in a Biological Life Support System.  

NASA Astrophysics Data System (ADS)

One problem in designing bioregenerative life support systems (BLSS) is developing technolo-gies to include human liquid and solid waste in intrasystem recycling. A specific task is recycling of NaCl excreted in urine by humans. We showed recently that this could be achieved through inclusion of the salt accumulating halophyte Salicornia europaea in the autotrophic compart-ment of the BLSS (Balnokin et al., ASR, 2010, in press). A model of NaCl circulation in BLSS with inclusion of S. europaea was based on the NaCl turnover in the human -urine -nutrient solution -S. europaea -human cycle. Mineralized urine was used as a basis for preparation of a nutrient solution for the halophyte cultivation. The shoots of the halophyte cultivated in the mineralized urine and containing NaCl could to be used by the BLSS inhabitants in their diets. In this report we describe cultivation of S. europaea which allows turnover of NaCl and produces daily shoot biomass containing Na+ and Cl- in quantities approximately equal to those excreted in daily human urine. The plants were grown in water culture in a climatic chamber under controlled conditions. A solution simulating mineralized urine (SSMU) was used as a basis for preparation of a nutri-ent solution for S. europaea cultivation. For continuous biomass production, seedlings of S. europaea, germinated preliminary in moist sand, were being transferred to the nutrient solu-tion at regular intervals (every two days). Duration of the conveyor operation was 112 days. During the first 56 days, the seedlings were being planted in SSMU diluted by a factor of 1.5 (2/3 SSMU). The same solution was introduced into the growth vessels as volumes of growth medium decreased due to plant transpiration. Starting from the 56th day as conveyor operation was initiated, the plants were being harvested every two days; the solutions from the discharged vessels were mixed with the fresh SSMU and the mixture was introduced into all other growth vessels of the conveyor. Thus, during the first 56-d period, the plants grew only in the fresh nutrient solution, whereas during the second 56-d period, the worked out nutrient solutions were being returned into the cycle having been added to the growth vessels along with the fresh SSMU. Growth characteristics, water and ionic relations of S. europaea plants, balance of nutrients between organs and growth media for the first and second 56-d periods of the conveyor operation are presented. There was no significant difference in the rates of shoot biomass production during the first and the second periods. The plants were producing shoot biomass with the rates close to those observed under optimal conditions. However, substantial increase in root biomass production (by 50% on the dry mass basis) was observed in the second period as compared with the first one. Decrease in organ water contents on the dry mass basis (by 13% and 30% for shoots and roots, respectively) and transpiration rates (by 25%) occurred also in the second period as compared with the first one. Measurements of Na+ , Cl- and nutrient contents in the growth media and plant organs and calculation of their balances showed that the plants did not suffer from a deficiency of nutrients during the 112 days of the conveyor operation while accumulating required NaCl amounts. Observed root proliferation and deterioration of water relations in the second 56-d period of the conveyor operation may be caused by toxic plant metabolites exuded by roots into the growth medium.

Balnokin, Yurii; Myasoedov, Nikolay; Popova, Larissa; Tikhomirov, Alexander A.; Ushakova, Sofya; Tikhomirova, Natalia; Lasseur, Christophe; Gros, Jean-Bernard

41

Growth promotion of the seawater-irrigated oilseed halophyte Salicornia bigelovii inoculated with mangrove rhizosphere bacteria and halotolerant Azospirillum spp  

Microsoft Academic Search

Inoculation of the oilseed halophyte Salicornia bigelovii Torr. with eight species of halotolerant bacteria, grown in seawater-irrigated pots under environmental conditions native\\u000a to the plant's habitat, resulted in significant plant growth promotion by the end of the growing season, 8–11?months later.\\u000a Statistical analysis demonstrated that inoculation with Azospirillum halopraeferens, a mixture of two Azospirillum brasilense strains, a mixture of Vibrio

Y. Bashan; M. Moreno; E. Troyo

2000-01-01

42

Manipulating the antioxidant capacity of halophytes to increase their cultural and economic value through saline cultivation  

PubMed Central

Halophytes, salt-tolerant plants, are a source of valuable secondary metabolites with potential economic value. The steady-state pools of many stress-related metabolites are already enhanced in halophytes when compared with glycophytes, but growth under conditions away from the optimum can induce stress and consequently result in changes to secondary metabolites such as antioxidants. However, direct evidence for increasing the concentration of valuable secondary metabolites as a consequence of altering the salinity of the growing environment still remains equivocal. To address this, we analysed a range of metabolites with antioxidant capacity (including total phenols, flavonoids, ascorbate, reduced/oxidized glutathione and reactive oxygen species scavenging enzymes) in seedlings and plants from different families (Amaranthaceae, Brassicaceae, Plantaginaceae and Rhizophoraceae) and habitats grown under different salt concentrations. We show that it is possible to manipulate the antioxidant capacity of plants and seedlings by altering the saline growing environment, the length of time under saline cultivation and the developmental stage. Among the species studied, the halophytes Tripolium pannonicum, Plantago coronopus, Lepidium latifolium and Salicornia europaea demonstrated the most potential as functional foods or nutraceuticals. PMID:25125698

Boestfleisch, Christian; Wagenseil, Niko B.; Buhmann, Anne K.; Seal, Charlotte E.; Wade, Ellie Merrett; Muscolo, Adele; Papenbrock, Jutta

2014-01-01

43

Plant responses to heterogeneous salinity: growth of the halophyte Atriplex nummularia is determined by the root-weighted mean salinity of the root zone  

PubMed Central

Soil salinity is generally spatially heterogeneous, but our understanding of halophyte physiology under such conditions is limited. The growth and physiology of the dicotyledonous halophyte Atriplex nummularia was evaluated in split-root experiments to test whether growth is determined by: (i) the lowest; (ii) the highest; or (iii) the mean salinity of the root zone. In two experiments, plants were grown with uniform salinities or horizontally heterogeneous salinities (10–450mM NaCl in the low-salt side and 670mM in the high-salt side, or 10mM NaCl in the low-salt side and 500–1500mM in the high-salt side). The combined data showed that growth and gas exchange parameters responded most closely to the root-weighted mean salinity rather than to the lowest, mean, or highest salinity in the root zone. In contrast, midday shoot water potentials were determined by the lowest salinity in the root zone, consistent with most water being taken from the least negative water potential source. With uniform salinity, maximum shoot growth was at 120–230mM NaCl; ~90% of maximum growth occurred at 10mM and 450mM NaCl. Exposure of part of the roots to 1500mM NaCl resulted in an enhanced (+40%) root growth on the low-salt side, which lowered root-weighted mean salinity and enabled the maintenance of shoot growth. Atriplex nummularia grew even with extreme salinity in part of the roots, as long as the root-weighted mean salinity of the root zone was within the 10–450mM range. PMID:23125356

Bazihizina, Nadia

2012-01-01

44

Germination of Dimorphic Seeds of the Desert Annual Halophyte Suaeda aralocaspica (Chenopodiaceae), a C4 Plant without Kranz Anatomy  

PubMed Central

Background and Aims Suaeda aralocaspica is a C4 summer annual halophyte without Kranz anatomy that is restricted to the deserts of central Asia. It produces two distinct types of seeds that differ in colour, shape and size. The primary aims of the present study were to compare the dormancy and germination characteristics of dimorphic seeds of S. aralocaspica and to develop a conceptual model of their dynamics. Methods Temperatures simulating those in the natural habitat of S. aralocaspica were used to test for primary dormancy and germination behaviour of fresh brown and black seeds. The effects of cold stratification, gibberellic acid, seed coat scarification, seed coat removal and dry storage on dormancy breaking were tested in black seeds. Germination percentage and recovery responses of brown seeds, non-treated black seeds and 8-week cold-stratified black seeds to salt stress were tested. Key Results Brown seeds were non-dormant, whereas black seeds had non-deep Type 2 physiological dormancy (PD). Germination percentage and rate of germination of brown seeds and of variously pretreated black seeds were significantly higher than those of non-pretreated black seeds. Exposure of seeds to various salinities had significant effects on germination, germination recovery and induction into secondary dormancy. A conceptual model is presented that ties these results together and puts them into an ecological context. Conclusions The two seed morphs of S. aralocaspica exhibit distinct differences in dormancy and germination characteristics. Suaeda aralocaspica is the first cold desert halophyte for which non-deep Type 2 PD has been documented. PMID:18772148

Wang, Lei; Huang, Zhenying; Baskin, Carol C.; Baskin, Jerry M.; Dong, Ming

2008-01-01

45

Genetically Altered Plant Species  

NASA Technical Reports Server (NTRS)

Researchers in Robert Ferl's lab at the University of Florida in Gainesville, genetically altered this Arabdopsis Thaliana (a brassica species) plant to learn how extreme environments, such as the low atmospheric pressure on Mars, affect plant genes. They inserted green fluorescent protein (GFP) near the on/off switches for anoxia and drought genes. When those genes were turned on after exposure to reduced atmospheric pressure, GFP was turned on as well, causing cells expressing those genes to glow green under a blue light. The natural fluorescence of chlorophyll accounts for the red glow.

2003-01-01

46

Comparative Ni tolerance and accumulation potentials between Mesembryanthemum crystallinum (halophyte) and Brassica juncea: Metal accumulation, nutrient status and photosynthetic activity.  

PubMed

Saline soils often constitute sites of accumulation of industrial and urban wastes contaminated by heavy metals. Halophytes, i.e. native salt-tolerant species, could be more suitable for heavy metal phytoextraction from saline areas than glycophytes, most frequently used so far. In the framework of this approach, we assess here the Ni phytoextraction potential in the halophyte Mesembryanthemum crystallinum compared with the model species Brassica juncea. Plants were hydroponically maintained for 21 days at 0, 25, 50, and 100?M NiCl2. Nickel addition significantly restricted the growth activity of both species, and to a higher extent in M. crystallinum, which did not, however, show Ni-related toxicity symptoms on leaves. Interestingly, photosynthesis activity, chlorophyll content and photosystem II integrity assessed by chlorophyll fluorescence were less impacted in Ni-treated M. crystallinum as compared to B. juncea. The plant mineral nutrition was differently affected by NiCl2 exposure depending on the element, the species investigated and even the organ. In both species, roots were the preferential sites of Ni(2+) accumulation, but the fraction translocated to shoots was higher in B. juncea than in M. crystallinum. The relatively good tolerance of M. crystallinum to Ni suggests that this halophyte species could be used in the phytoextraction of moderately polluted saline soils. PMID:25171515

Amari, Taoufik; Ghnaya, Tahar; Debez, Ahmed; Taamali, Manel; Ben Youssef, Nabil; Lucchini, Giorgio; Sacchi, Gian Attilio; Abdelly, Chedly

2014-11-01

47

Medicinal halophytes: potent source of health promoting biomolecules with medical, nutraceutical and food applications.  

PubMed

Salt-tolerant plants grow in a wide variety of saline habitats, from coastal regions, salt marshes and mudflats to inland deserts, salt flats and steppes. Halophytes living in these extreme environments have to deal with frequent changes in salinity level. This can be done by developing adaptive responses including the synthesis of several bioactive molecules. Consequently, several salt marsh plants have traditionally been used for medical, nutritional, and even artisanal purposes. Currently, an increasing interest is granted to these species because of their high content in bioactive compounds (primary and secondary metabolites) such as polyunsaturated fatty acids, carotenoids, vitamins, sterols, essential oils (terpenes), polysaccharides, glycosides, and phenolic compounds. These bioactive substances display potent antioxidant, antimicrobial, anti-inflammatory, and anti-tumoral activities, and therefore represent key-compounds in preventing various diseases (e.g. cancer, chronic inflammation, atherosclerosis and cardiovascular disorder) and ageing processes. The ongoing research will lead to the utilisation of halophytes as a new source of healthy products as functional foods, nutraceuticals or active principles in several industries. This contribution focuses on the ethnopharmacological uses of halophytes in traditional medicine and reviews recent investigations on their biological activities and nutraceuticals. The work is distributed according to the different families of nutraceuticals (lipids, vitamins, proteins, glycosides, phenolic compounds, etc.) discussing the analytical techniques employed for their determination. Information about the claimed health promoting effects of the different families of nutraceuticals is also provided together with data on their application. PMID:22129270

Ksouri, Riadh; Ksouri, Wided Megdiche; Jallali, Inès; Debez, Ahmed; Magné, Christian; Hiroko, Isoda; Abdelly, Chedly

2012-12-01

48

Z .Aquaculture 175 1999 255268 Halophytes for the treatment of saline aquaculture  

E-print Network

Z .Aquaculture 175 1999 255­268 Halophytes for the treatment of saline aquaculture effluent J. Jed the feasibility of using salt-tolerant plants halophytes as biofilters to remove nutrients from saline aquaculture fraction, using aquaculture effluent generated from an intensive tilapia culture system. The effluent

Smith, Steven E.

49

Assessment of the potential of halophytes as energy crops for the electric utility industry. Final report  

Microsoft Academic Search

This technical report assesses and estimates the potential of selected halophytes as future renewable energy resources, especially by US electric utilities, and familiarizes nonspecialists with research and development problems that must be resolved before these energy sources can become dependable supplies of energy. A literature search related to both indigenous and exotic species of halophytes has been done and appropriate

Goodin

1984-01-01

50

C:N:P Stoichiometry and Leaf Traits of Halophytes in an Arid Saline Environment, Northwest China  

PubMed Central

Salinization is an important and increasingly prevalent issue which has broad and profound effects on plant survival and distribution pattern. To understand the patterns and potential drivers of leaf traits in saline environments, we determined the soil properties, leaf morphological traits (specific leaf area, SLA, and leaf dry matter content, LDMC), leaf chemical traits (leaf carbon, C, nitrogen, N, and phosphorus, P, stoichiometry) based on 142 observations collected from 23 sites in an arid saline environment, which is a vulnerable ecosystem in northwest China. We also explored the relationships among leaf traits, the responses of leaf traits, and plant functional groups (herb, woody, and succulent woody) to various saline environments. The arid desert halophytes were characterized by lower leaf C and SLA levels, higher N, but stable P and N:P. The leaf morphological traits were correlated significantly with the C, N, and P contents across all observations, but they differed within each functional group. Succulent woody plants had the lowest leaf C and highest leaf N levels among the three functional groups. The growth of halophytes might be more limited by N rather than P in the study area. GLM analysis demonstrated that the soil available nutrients and plant functional groups, but not salinity, were potential drivers of leaf C:N:P stoichiometry in halophytes, whereas species differences accounted for the largest contributions to leaf morphological variations. Our study provides baseline information to facilitate the management and restoration of arid saline desert ecosystem. PMID:25798853

Wang, Lilong; Zhao, Guanxiang; Li, Meng; Zhang, Mingting; Zhang, Lifang; Zhang, Xinfang; An, Lizhe; Xu, Shijian

2015-01-01

51

C:N:p stoichiometry and leaf traits of halophytes in an arid saline environment, northwest china.  

PubMed

Salinization is an important and increasingly prevalent issue which has broad and profound effects on plant survival and distribution pattern. To understand the patterns and potential drivers of leaf traits in saline environments, we determined the soil properties, leaf morphological traits (specific leaf area, SLA, and leaf dry matter content, LDMC), leaf chemical traits (leaf carbon, C, nitrogen, N, and phosphorus, P, stoichiometry) based on 142 observations collected from 23 sites in an arid saline environment, which is a vulnerable ecosystem in northwest China. We also explored the relationships among leaf traits, the responses of leaf traits, and plant functional groups (herb, woody, and succulent woody) to various saline environments. The arid desert halophytes were characterized by lower leaf C and SLA levels, higher N, but stable P and N:P. The leaf morphological traits were correlated significantly with the C, N, and P contents across all observations, but they differed within each functional group. Succulent woody plants had the lowest leaf C and highest leaf N levels among the three functional groups. The growth of halophytes might be more limited by N rather than P in the study area. GLM analysis demonstrated that the soil available nutrients and plant functional groups, but not salinity, were potential drivers of leaf C:N:P stoichiometry in halophytes, whereas species differences accounted for the largest contributions to leaf morphological variations. Our study provides baseline information to facilitate the management and restoration of arid saline desert ecosystem. PMID:25798853

Wang, Lilong; Zhao, Guanxiang; Li, Meng; Zhang, Mingting; Zhang, Lifang; Zhang, Xinfang; An, Lizhe; Xu, Shijian

2015-01-01

52

Membrane-forming lipids of wild halophytes growing under the conditions of Prieltonie of South Russia.  

PubMed

The composition of membrane-forming lipids has been examined for 10 wild halophyte species growing in southern Russian on alkaline soil. The plants belong to seven taxa of family rank: by their life form, which are semi-shrubs, herbaceous annuals, and perennial plants; their salt tolerance, which are classified as the euhalophytes, crynohalophytes, and glycohalophytes; and by their sensitivity to water, classifications of mesoxerophytes and xeromesophytes. Parallels have been found between the lipid composition and the ecological status of the plants. It has also been revealed that the similarity in the glyco- and phospholipid composition of different plant groups relates to the water factor and the type of salt accumulation, respectively. The fatty acid compositions of the examined plants is determined at the species level. PMID:24890389

Rozentsvet, Olga A; Nesterov, Victor N; Bogdanova, Elena S

2014-09-01

53

The role of proline accumulation in halophytes.  

PubMed

It is shown that in the majority of higher plant halophytes examined proline is the major component of the amino acid pool in plants collected from the field. In Triglochin maritima L. free proline can represent 10-20% of the shoot dry weight. Under non-saline conditions proline levels are low and increase as the salinity is raised. Comparisons of inland and coastal populations of Ameria maritima Willd. suggest that the capacity to accumulate proline is correlated with salt tolerance. It is suggested that proline functions as a source of solute for intracellular osmotic adjustments under saline conditions. PMID:24442703

Stewart, G R; Lee, J A

1974-01-01

54

Physiological and proteomic analyses of leaves from the halophyte Tangut Nitraria reveals diverse response pathways critical for high salinity tolerance  

PubMed Central

Soil salinization poses a serious threat to the environment and agricultural productivity worldwide. Studies on the physiological and molecular mechanisms of salinity tolerance in halophytic plants provide valuable information to enhance their salt tolerance. Tangut Nitraria is a widely distributed halophyte in saline–alkali soil in the northern areas of China. In this study, we used a proteomic approach to investigate the molecular pathways of the high salt tolerance of T. Nitraria. We analyzed the changes in biomass, photosynthesis, and redox-related enzyme activities in T. Nitraria leaves from plant seedlings treated with high salt concentration. Comparative proteomic analysis of the leaves revealed that the expression of 71 proteins was significantly altered after salinity treatments of T. Nitraria. These salinity-responsive proteins were mainly involved in photosynthesis, redox homeostasis, stress/defense, carbohydrate and energy metabolism, protein metabolism, signal transduction, and membrane transport. Results showed that the reduction of photosynthesis under salt stress was attributed to the down-regulation of the enzymes and proteins involved in the light reaction and Calvin cycle. Protein–protein interaction analysis revealed that the proteins involved in redox homeostasis, photosynthesis, and energy metabolism constructed two types of response networks to high salt stress. T. Nitraria plants developed diverse mechanisms for scavenging reactive oxygen species (ROS) in their leaves to cope with stress induced by high salinity. This study provides important information regarding the salt tolerance of the halophyte T. Nitraria. PMID:25713577

Cheng, Tielong; Chen, Jinhui; Zhang, Jingbo; Shi, Shengqing; Zhou, Yanwei; Lu, Lu; Wang, Pengkai; Jiang, Zeping; Yang, Jinchang; Zhang, Shougong; Shi, Jisen

2015-01-01

55

Seaweeds and halophytes to remove carbon from the atmosphere  

SciTech Connect

The utility industry and other interested parties have investigated strategies to mitigate the buildup of atmospheric CO{sub 2}. One option that has been considered is the planting of trees on a massive scale to absorb carbon through photosynthesis. A dilemma of using tree plantations, however, is that they might occupy land that will be needed for food production or other needs for an expected doubling of human population in the tropical regions. We evaluated seaweeds and salt-tolerant terrestrial plants (halophytes) to be grown on the coastal shelves and salt deserts of the world as possible alternatives to tree plantations. An estimated 1.3 {times} 10{sup 6} km{sup 2} of continental shelf and 1.3 {times} 10{sup 6} km{sup 2} of salt desert may be usable for seaweed and halophyte plantations. The production rates of managed seaweed and halophyte plantings are similar to managed tree plantations. Seaweeds and halophytes could conceivably absorb 10--20% of annual fossil fuel carbon emissions through biomass production, similar to estimates made for tree plantations. Present costs of halophyte biomass production are similar to costs of tree biomass production, whereas seaweed biomass is much more expensive to produce using existing technologies. Storage of seaweed carbon might be accomplished by allowing it to enter the sediment detritus chain whereas halophyte carbon might be sequestered in the soil, or used as biomass fuel. As has been concluded for reforestation, these saline biomass crops could at best help delay rather than solve the carbon dioxide build-up problem. 1 fig., 13 tabs.

Glenn, E.P.; Kent, K.J.; Thompson, T.L.; Frye, R.J. (Arizona Univ., Tucson, AZ (USA). Environmental Research Lab.)

1991-02-01

56

Comparative study of rhizobacterial community structure of plant species in oil-contaminated soil.  

PubMed

In this study, the identity and distribution of plants and the structure of their associated rhizobacterial communities were examined in an oil-contaminated site. The number of plant species that formed a community or were scattered was 24. The species living in soil highly contaminated with total petroleum hydrocarbon (TPH) (9,000-4,5000 mg/g-soil) were Cynodon dactylon, Persicaria lapathifolia, and Calystegia soldanella (a halophytic species). Among the 24 plant species, the following have been known to be effective for oil removal: C. dactylon, Digitaria sanguinalis, and Cyperus orthostachyus. Denaturing gradient gel electrophoresis (DGGE) profile analysis showed that the following pairs of plant species had highly similar (above 70%) rhizobacterial community structures: Artemisia princeps and Hemistepta lyrata; C. dactylon and P. lapathifolia; Carex kobomugi and Cardamine flexuosa; and Equisetum arvense and D. sanguinalis. The major groups of rhizobacteria were Betaproteobacteria, Gamma-proteobacteria, Chloroflexi, Actinobacteria, and unknown. Based on DGGE analysis, P. lapathifolia, found for the first time in this study growing in the presence of high TPH, may be a good species for phytoremediation of oil-contaminated soils and in particular, C. soldanella may be useful for soils with high TPH and salt concentrations. Overall, this study suggests that the plant roots, regardless of plant species, may have a similar influence on the bacterial community structure in oil-contaminated soil. PMID:20890100

Lee, Eun-Hee; Cho, Kyong-Suk; Kim, Jaisoo

2010-09-01

57

Sodium relations in desert plants. V. Cation balance when grown in solution culture and in the field in three species of Lycium from the northern Mojave desert  

Microsoft Academic Search

Three species of Lycium (wolfberry or desert thorn) are indicators of saline conditions of the soils of the northern Mojave Desert on which they grow and range from a halophyte (Lycium shockleyi Gray) to a partial halophyte (Lycium pallidum Miers) to a nonhalophyte (Lycium andersonii Gray). Each species was grown in nutrient solutions with varying Na levels to determine if

R. T. Ashcroft; A. Wallace

1976-01-01

58

Responses of five Mediterranean halophytes to seasonal changes in environmental conditions  

PubMed Central

In their natural habitats, different mechanisms may contribute to the tolerance of halophytes to high soil salinity and other abiotic stresses, but their relative contribution and ecological relevance, for a given species, remain largely unknown. We studied the responses to changing environmental conditions of five halophytes (Sarcocornia fruticosa, Inula crithmoides, Plantago crassifolia, Juncus maritimus and J. acutus) in a Mediterranean salt marsh, from summer 2009 to autumn 2010. A principal component analysis was used to correlate soil and climatic data with changes in the plants' contents of chemical markers associated with stress responses: ions, osmolytes, malondialdehyde (MDA, a marker of oxidative stress) and antioxidant systems. Stress tolerance in S. fruticosa, I. crithmoides and P. crassifolia (all succulent dicots) seemed to depend mostly on the transport of ions to aerial parts and the biosynthesis of specific osmolytes, whereas both Juncus species (monocots) were able to avoid accumulation of toxic ions, maintaining relatively high K+/Na+ ratios. For the most salt-tolerant taxa (S. fruticosa and I. crithmoides), seasonal variations of Na+, Cl?, K+ and glycine betaine, their major osmolyte, did not correlate with environmental parameters associated with salt or water stress, suggesting that their tolerance mechanisms are constitutive and relatively independent of external conditions, although they could be mediated by changes in the subcellular compartmentalization of ions and compatible osmolytes. Proline levels were too low in all the species to possibly have any effect on osmotic adjustment. However—except for P. crassifolia—proline may play a role in stress tolerance based on its ‘osmoprotectant’ functions. No correlation was observed between the degree of environmental stress and the levels of MDA or enzymatic and non-enzymatic antioxidants, indicating that the investigated halophytes are not subjected to oxidative stress under natural conditions and do not, therefore, need to activate antioxidant defence mechanisms. PMID:25139768

Gil, Ricardo; Bautista, Inmaculada; Boscaiu, Monica; Lidón, Antonio; Wankhade, Shantanu; Sánchez, Héctor; Llinares, Josep; Vicente, Oscar

2014-01-01

59

Responses of five Mediterranean halophytes to seasonal changes in environmental conditions.  

PubMed

In their natural habitats, different mechanisms may contribute to the tolerance of halophytes to high soil salinity and other abiotic stresses, but their relative contribution and ecological relevance, for a given species, remain largely unknown. We studied the responses to changing environmental conditions of five halophytes (Sarcocornia fruticosa, Inula crithmoides, Plantago crassifolia, Juncus maritimus and J. acutus) in a Mediterranean salt marsh, from summer 2009 to autumn 2010. A principal component analysis was used to correlate soil and climatic data with changes in the plants' contents of chemical markers associated with stress responses: ions, osmolytes, malondialdehyde (MDA, a marker of oxidative stress) and antioxidant systems. Stress tolerance in S. fruticosa, I. crithmoides and P. crassifolia (all succulent dicots) seemed to depend mostly on the transport of ions to aerial parts and the biosynthesis of specific osmolytes, whereas both Juncus species (monocots) were able to avoid accumulation of toxic ions, maintaining relatively high K(+)/Na(+) ratios. For the most salt-tolerant taxa (S. fruticosa and I. crithmoides), seasonal variations of Na(+), Cl(-), K(+) and glycine betaine, their major osmolyte, did not correlate with environmental parameters associated with salt or water stress, suggesting that their tolerance mechanisms are constitutive and relatively independent of external conditions, although they could be mediated by changes in the subcellular compartmentalization of ions and compatible osmolytes. Proline levels were too low in all the species to possibly have any effect on osmotic adjustment. However-except for P. crassifolia-proline may play a role in stress tolerance based on its 'osmoprotectant' functions. No correlation was observed between the degree of environmental stress and the levels of MDA or enzymatic and non-enzymatic antioxidants, indicating that the investigated halophytes are not subjected to oxidative stress under natural conditions and do not, therefore, need to activate antioxidant defence mechanisms. PMID:25139768

Gil, Ricardo; Bautista, Inmaculada; Boscaiu, Monica; Lidón, Antonio; Wankhade, Shantanu; Sánchez, Héctor; Llinares, Josep; Vicente, Oscar

2014-01-01

60

Responses of halophytes to high salinities and low water potentials.  

PubMed

The effects of nonsaline polyethylene glycol (PEG)-6000 and saline seawater solutions of comparable osmotic potential on the concentrations of organic solutes and inorganic ions in the tissues of halophytes (Plantago maritima L., Triglochin maritima L., Limonium vulgare Mill., Halimione portulacoides (L.) Aell) have been investigated. Studies were made to determine whether high salinities induce specific ion effects that are absent in plants grown in nonsaline solutions of comparable osmotic potential. Over-all, the responses of each species to the two different treatments (seawater or PEG) are similar; the accumulation of organic solutes (compatible osmotica) in tissues is primarily correlated with a decrease in the osmotic potential of culture solutions. Depending on the species, sorbitol, proline, reducing sugars, quaternary ammonium compounds, and alpha-amino nitrogen accumulate in tissues as the water potential of the tissues falls. Within a species there are differences in the concentrations of inorganic ions and organic solutes between roots and shoots of plants grown at high salinities or at high concentrations of PEG. PMID:16661119

Jefferies, R L; Rudmik, T; Dillon, E M

1979-12-01

61

Effect of saline water on seed germination and early seedling growth of the halophyte quinoa.  

PubMed

Salinization is increasing on a global scale, decreasing average yields for most major crop plants. Investigations into salt resistance have, unfortunately, mainly been focused on conventional crops, with few studies screening the potential of available halophytes as new crops. This study has been carried out to investigate the mechanisms used by quinoa, a facultative halophytic species, in order to cope with high salt levels at various stages of its development. Quinoa is regarded as one of the crops that might sustain food security in this century, grown primarily for its edible seeds with their high protein content and unique amino acid composition. Although the species has been described as a facultative halophyte, and its tolerance to salt stress has been investigated, its physiological and molecular responses to seawater (SW) and other salts have not been studied. We evaluated the effects of SW and different salts on seed germination, seedling emergence and the antioxidative pathway of quinoa. Seeds were germinated in Petri dishes and seedlings grown in pots with SW solutions (25, 50, 75 and 100 %) and NaCl, CaCl2, KCl and MgCl2 individually, at the concentrations in which they are present in SW. Our results demonstrated that all salts, at lower concentrations, increased the germination rate but not the germination percentages, compared with control (pure water). Conversely, seedlings were differently affected by treatments in respect to salt type and concentration. Growth parameters affected were root and shoot length, root morphology, fresh and dry weight, and water content. An efficient antioxidant mechanism was present in quinoa, activated by salts during germination and early seedling growth, as shown by the activities of antioxidant enzymes. Total antioxidant capacity was always higher under salt stress than in water. Moreover, osmotic and ionic stress factors had different degrees of influence on germination and development. PMID:25139769

Panuccio, M R; Jacobsen, S E; Akhtar, S S; Muscolo, A

2014-01-01

62

EDTA-enhanced phytoremediation of lead-contaminated soil by the halophyte Sesuvium portulacastrum.  

PubMed

The low bioavailability of Pb and low number of Pb-tolerant plant species represent an important limitation for Pb phytoextraction. It was recently suggested that halophyte plant species may be a promising material for this purpose, especially in polluted salt areas while Pb mobility may be improved by synthetic chelating agents. This study aims to evaluate Pb extraction by the halophyte Sesuvium portulacastrum in relation to the impact of EDTA application. Seedling were cultivated during 60 days on Pb artificially contaminated soil (200, 400, and 800 ppm Pb) in the presence or in the absence of EDTA (3 g kg(-1) soil). Results showed that upon to 400 ppm, Pb had no impact on plant growth. However, exogenous Pb induce a decrease in shoot K(+) while it increased shoot Mg(2+) and had no impact on shoot Ca(2+) concentrations. Lead concentration in the shoots increased with increasing external Pb doses reaching 1,390 ppm in the presence of 800 ppm lead in soil. EDTA addition had no effect on plant growth but strongly increased Pb accumulation in the shoot which increased from 1,390 ppm in the absence of EDTA to 3,772 ppm in EDTA-amended plants exposed to 800 ppm exogenous Pb. Both Pb absorption and translocation from roots to shoots were significantly enhanced by EDTA application, leading to an increase in the total amounts of extracted Pb per plant. These data suggest that S. portulacastrum is very promising species for decontamination of Pb(2+)-contaminated soil and that its phytoextraction potential was significantly enhanced by addition of EDTA to the polluted soil. PMID:24604274

Zaier, Hanen; Ghnaya, Tahar; Ghabriche, Rim; Chmingui, Walid; Lakhdar, Abelbasset; Lutts, Stanley; Abdelly, Chedly

2014-06-01

63

Effectiveness of the aquatic halophyte Sarcocornia perennis spp. perennis as a biotool for ecological restoration of metal-contaminated salt marshes  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ecological restoration and creation of salt marshes is needed to compensate for their degradation and loss, but little is known about halophytes as plant biotools in restoration projects. Restoration plantings of halophytes have been established following eradication of invasive populations of the e...

64

Growth responses and ion accumulation in the halophytic legume Prosopis strombulifera are determined by Na2 SO4 and NaCl.  

PubMed

Halophytes are potential gene sources for genetic manipulation of economically important crop species. This study addresses the physiological responses of a widespread halophyte, Prosopis strombulifera (Lam.) Benth to salinity. We hypothesised that increasing concentrations of the two major salts present in soils of central Argentina (Na2 SO4 , NaCl, or their iso-osmotic mixture) would produce distinct physiological responses. We used hydroponically grown P. strombulifera to test this hypothesis, analysing growth parameters, water relations, photosynthetic pigments, cations and anions. These plants showed a halophytic response to NaCl, but strong general inhibition of growth in response to iso-osmotic solutions containing Na2 SO4 . The explanation for the adaptive success of P. strombulifera in high NaCl conditions seems to be related to a delicate balance between Na(+) accumulation (and its use for osmotic adjustment) and efficient compartmentalisation in vacuoles, the ability of the whole plant to ensure sufficient K(+) supply by maintaining high K(+) /Na(+) discrimination, and maintenance of normal Ca(2+) levels in leaves. The three salt treatments had different effects on the accumulation of ions. Findings in bi-saline-treated plants were of particular interest, where most of the physiological parameters studied showed partial alleviation of SO4 (2-) -induced toxicity by Cl(-) . Thus, discussions on physiological responses to salinity could be further expanded in a way that more closely mimics natural salt environments. PMID:23869994

Reginato, M; Sosa, L; Llanes, A; Hampp, E; Vettorazzi, N; Reinoso, H; Luna, V

2013-07-22

65

High apoplastic solute concentrations in leaves alter water relations of the halophytic shrub, Sarcobatus vermiculatus  

Microsoft Academic Search

Predawn plant water potential (Ww) is used to estimate soil moisture available to plants because plants are expected to equilibrate with the root-zone Ww. Although this equilibrium assumption provides the basis for interpreting many physiological and ecological param- eters, much work suggests predawn plant Ww is often more negative than root-zone soil Ww. For many halophytes even when soils are

J. J. James; N. N. Alder; K. H. Muhling; A. E. Lauchli; K. A. Shackel; L. A. Donovan; J. H. Richards

2006-01-01

66

Abscisic acid has contrasting effects on salt excretion and polyamine concentrations of an inland and a coastal population of the Mediterranean xero-halophyte species Atriplex halimus  

PubMed Central

Background and Aims Different populations of the Mediterranean xerohalophyte species Atriplex halimus exhibit different levels of resistance to salt and osmotic stress depending on the nature of the osmocompatible solute they accumulate. There is, however, no conclusive description of the involvement of abscisic acid (ABA) in the plant response to NaCl or osmotic stress in this species. Methods Seedlings issued from an inland water-stress-resistant population (Sbikha) and from a coastal salt-resistant one (Monastir) were exposed in nutrient solutions to NaCl (40 or 160 mm) or to 15 % PEG for 1 d and 10 d in the presence or absence of 50 µm ABA. Key Results Plants from Sbikha accumulated higher amounts of ABA in response to osmotic stress than those of Monastir, while an opposite trend was recorded for NaCl exposure. Exogenous ABA improved osmotic stress resistance in Monastir through an improvement in the efficiency of stomatal conductance regulation. It also improved NaCl resistance in Sbikha through an increase in sodium excretion through the external bladders. It is suggested that polyamines (spermidine and spermine) are involved in the salt excretion process and that ABA contributes to polyamine synthesis as well as to the conversion from the bound and conjugated to the free soluble forms of polyamine. Proline accumulated in response to osmotic stress and slightly increased in response to ABA treatment while glycinebetaine accumulated in response to salinity and was not influenced by ABA. Conclusions It is concluded that ABA is involved in both salt and osmotic stress resistance in the xerohalophyte species Atriplex halimus but that it acts on different physiological cues in response to those distinct environmental constraints. PMID:19666900

Ben Hassine, A.; Ghanem, M. E.; Bouzid, S.; Lutts, S.

2009-01-01

67

How successful are plant species reintroductions?  

Microsoft Academic Search

Reintroduction of native species has become increasingly important in conservation worldwide for recovery of rare species and restoration purposes. However, few studies have reported the outcome of reintroduction efforts in plant species. Using data from the literature combined with a questionnaire survey, this paper analyses 249 plant species reintroductions worldwide by assessing the methods used and the results obtained from

Sandrine Godefroid; Carole Piazza; Graziano Rossi; Stéphane Buord; Albert-Dieter Stevens; Ruth Aguraiuja; Carly Cowell; Carl W. Weekley; Gerd Vogg; José M. Iriondo; Isabel Johnson; Bob Dixon; Doria Gordon; Sylvie Magnanon; Bertille Valentin; Kristina Bjureke; Rupert Koopman; Magdalena Vicens; Myriam Virevaire; Thierry Vanderborght

2011-01-01

68

Halophytes, Algae, and Bacteria Food and Fuel Feedstocks  

NASA Technical Reports Server (NTRS)

The constant, increasing demand for energy, freshwater, and food stresses our ability to meet these demands within reasonable cost and impact on climate while sustaining quality of life. This environmental Triangle of Conflicts between energy, food, and water--while provoked by anthropogenic monetary and power struggles--can be resolved through an anthropogenic paradigm shift in how we produce and use energy, water, and food. With world population (6.6 billion) projected to increase 40 percent in 40 to 60 yr, proper development of saline agriculture and aquaculture is required, as 43 percent of the Earth's landmass is arid or semi-arid and 97 percent of the Earth's water is seawater. In light of this, we seek fuel alternatives in plants that thrive in brackish and saltwater with the ability to survive in arid lands. The development and application of these plants (halophytes) become the primary focus. Herein we introduce some not-so-familiar halophytes and present a few of their benefits, cite a few research projects (including some on the alternatives algae and bacteria), and then set theoretical limits on biomass production followed by projections in terms of world energy demands. Based on diverse arid lands with a total size equivalent to the Sahara Desert (8.6(exp 8) ha, or 2.1(exp 9) acres), these projections show that halophyte agriculture and algae systems can provide for the projected world energy demand.

Hendricks, R. C.; Bushnell, D. M.

2009-01-01

69

Salt tolerance is related to a specific antioxidant response in the halophyte cordgrass, Spartina densiflora  

NASA Astrophysics Data System (ADS)

Halophytes usually have a robust antioxidative defense system to alleviate oxidative damage during salt stress. Spartina densiflora is a colonizing halophyte cordgrass, native of South America, which has become a common species in salt marshes of northern hemisphere, where it is ousting indigenous species. This study addressed salinity stress in S. densiflora; the occurrence of oxidative stress and the possible involvement of the antioxidative system in its high salt tolerance were studied. Plants were evaluated at in situ conditions, in the laboratory during a 28 day-acclimation period (AP) in clean substrate irrigated with a control salt content of 4 g L-1 (68 mM) and during a subsequent 28 day-treatment period (TP) exposed to different NaCl concentrations: control (68 mM), 428 mM or 680 mM. In the in situ setting, the high leave Na+ content was accompanied by high levels of hydroperoxides and reduced levels of total chlorophyll and carotenes, which correlated with enhanced activation of antioxidant defense biomarkers as total ascorbic acid (AA) content and guaiacol peroxidase (POD: EC 1.11.1.7)), catalase (CAT: EC 1.11.1.6) and ascorbate peroxidase (APX: EC 1.11.1.11) activities. Throughout the AP, leave Na+ and oxidative stress markers decreased concomitantly and reached stable low levels. During the TP, dose and time-dependent accumulation of Na+ in high NaCl-treated plants was concurrent with a decrease in content of total chlorophyll and carotenes and with an increase in the levels of total AA and CAT and APX activities. In conclusion, as hypothesized, high salinity induces conditions of oxidative stress in S. densiflora, so that its salt tolerance appears to be related to the implementation of a specific antioxidant response. This may account for Spartina densiflora's successful adaptation to habitats with fluctuating salinity and favour its phytoremediation potential.

Canalejo, Antonio; Martínez-Domínguez, David; Córdoba, Francisco; Torronteras, Rafael

2014-06-01

70

Endangered Species (Plants). LC Science Tracer Bullet.  

ERIC Educational Resources Information Center

This guide is intended for those who wish to study the literature dealing with various aspects of endangered plant species. This document includes the following sections, some of which are bibliographies: (1) "Introductions to the Topic"; (2) "Subject Headings" (for endangered species of plants used by the Library of Congress); (3) "General…

Niskern, Diana, Comp.

71

The Invasive Plant Species Education Guide  

ERIC Educational Resources Information Center

To help high school students gain a solid understanding of invasive plant species, university faculty and students from the University of Wisconsin-Stout (UW-Stout) and a local high school teacher worked together to develop the Invasive Plant Species (IPS) Education Guide. The IPS Education Guide includes nine lessons that give students an…

Mason, Kevin; James, Krista; Carlson, Kitrina; D'Angelo, Jean

2010-01-01

72

The Invasive Plant Species Education Guide  

NSDL National Science Digital Library

To help high school students gain a solid understanding of invasive plant species, university faculty and students from the University of Wisconsin-Stout (UW-Stout) and a local high school teacher worked together to develop the Invasive Plant Species (IPS

Jean D'Angelo

2010-04-01

73

Seeding conditions of the halophyte Atriplex patula for optimal growth on a salt impacted site.  

PubMed

Salt-impacted soils resulting from oilfield brine spills are increasingly becoming a significant problem in oil-producing areas of Canada such as Alberta and Saskatchewan. The native halophyte Atriplex patula is being considered a potential species for phytoremediation of brine-impacted sites in these hemiboreal climactic zones. The objective of this study was to investigate the optimal seeding conditions under field conditions (with no irrigation) of A. patula for phytoremediation of salt from a brine-impacted site. Atriplex patula was identified in preliminary greenhouse trials to have one of the highest salt accumulations in relation to plant yields. Different seeding methods of A. patula were assessed in an attempt to achieve reproducible growth of this species. While plant yields for A. patula were improved on compacted soil by approximately 30-50%, growth was uneven with regard to density and height. The uneven growth may be due to seed quality and low precipitation during the field season, while improvements in plant yield on compact soil might be due to a lack of competition with other species. PMID:21972494

Young, Michelle A; Rancier, Doug G; Roy, Julie L; Lunn, Stuart R; Armstrong, Sarah A; Headley, John V

2011-08-01

74

Applying the species concept to plant viruses  

Microsoft Academic Search

Summary Plant virologists who maintain that the concept of species cannot be applied to viruses argue their case in terms of an obsolete concept of biological species defined by gene pools and reproductive isolation and applicable only to sexually reproducing organisms. In fact, various species concepts have been used by biologists and some of them are applicable to asexual organisms.

M. H. V. Van Regenmortel

1989-01-01

75

Exotic plant species invade hot spots of native plant diversity  

USGS Publications Warehouse

Some theories and experimental studies suggest that areas of low plant species richness may be invaded more easily than areas of high plant species richness. We gathered nested-scale vegetation data on plant species richness, foliar cover, and frequency from 200 1-m2 subplots (20 1000-m2 modified-Whittaker plots) in the Colorado Rockies (USA), and 160 1-m2 subplots (16 1000-m2 plots) in the Central Grasslands in Colorado, Wyoming, South Dakota, and Minnesota (USA) to test the generality of this paradigm. At the 1-m2 scale, the paradigm was supported in four prairie types in the Central Grasslands, where exotic species richness declined with increasing plant species richness and cover. At the 1-m2 scale, five forest and meadow vegetation types in the Colorado Rockies contradicted the paradigm; exotic species richness increased with native-plant species richness and foliar cover. At the 1000-m2 plot scale (among vegetation types), 83% of the variance in exotic species richness in the Central Grasslands was explained by the total percentage of nitrogen in the soil and the cover of native plant species. In the Colorado Rockies, 69% of the variance in exotic species richness in 1000-m2 plots was explained by the number of native plant species and the total percentage of soil carbon. At landscape and biome scales, exotic species primarily invaded areas of high species richness in the four Central Grasslands sites and in the five Colorado Rockies vegetation types. For the nine vegetation types in both biomes, exotic species cover was positively correlated with mean foliar cover, mean soil percentage N, and the total number of exotic species. These patterns of invasibility depend on spatial scale, biome and vegetation type, spatial autocorrelation effects, availability of resources, and species-specific responses to grazing and other disturbances. We conclude that: (1) sites high in herbaceous foliar cover and soil fertility, and hot spots of plant diversity (and biodiversity), are invasible in many landscapes; and (2) this pattern may be more closely related to the degree resources are available in native plant communities, independent of species richness. Exotic plant invasions in rare habitats and distinctive plant communities pose a significant challenge to land managers and conservation biologists.

Stohlgren, T.J.; Binkley, D.; Chong, G.W.; Kalkhan, M.A.; Schell, L.D.; Bull, K.A.; Otsuki, Y.; Newman, G.; Bashkin, M.; Yowhan, S.

1999-01-01

76

Why Some Plant Species Are Rare  

PubMed Central

Biodiversity, including plant species diversity, is threatened worldwide as a result of anthropogenic pressures such as an increase of pollutants and climate change. Rare species in particular are on the verge of becoming extinct. It is still unclear as to why some plant species are rare and others are not. Are they rare due to: intrinsic reasons, dispersal capacity, the effects of management or abiotic circumstances? Habitat preference of rare plant species may play an important role in determining why some species are rare. Based on an extensive data set of soil parameters we investigated if rarity is due to a narrow habitat preference for abiotic soil parameters. For 23 different abiotic soil parameters, of which the most influential were groundwater-table, soil-pH and nutrient-contents, we estimated species responses for common and rare species. Based on the responses per species we calculated the range of occurrence, the range between the 5 and 95 percentile of the response curve giving the habitat preference. Subsequently, we calculated the average response range for common and rare species. In addition, we designed a new graphic in order to provide a better means for presentation of the results. The habitat preferences of rare species for abiotic soil conditions are significantly narrower than for common species. Twenty of the twenty-three abiotic parameters showed on average significantly narrower habitat preferences for rare species than for common species; none of the abiotic parameters showed on average a narrower habitat preference for common species. The results have major implications for the conservation of rare plant species; accordingly management and nature development should be focussed on the maintenance and creation of a broad range of environmental conditions, so that the requirements of rare species are met. The conservation of (abiotic) gradients within ecosystems is particularly important for preserving rare species. PMID:25054424

Wamelink, G. W. Weiger; Goedhart, Paul W.; Frissel, Josep Y.

2014-01-01

77

Exotic Plant Species Invade Hot Spots of Native Plant Diversity  

Microsoft Academic Search

Some theories and experimental studies suggest that areas of low plant spe- cies richness may be invaded more easily than areas of high plant species richness. We gathered nested-scale vegetation data on plant species richness, foliar cover, and frequency from 200 1-m2 subplots (20 1000-m2 modified-Whittaker plots) in the Colorado Rockies (USA), and 160 1-m2 subplots (16 1000-m2 plots) in

Thomas J. Stohlgren; Dan Binkley; Geneva W. Chong; Mohammed A. Kalkhan; Lisa D. Schell; Kelly A. Bull; Yuka Otsuki; Gregory Newman; Michael Bashkin; Yowhan Son

1999-01-01

78

Responses of Halophytes to High Salinities and Low Water Potentials 1  

PubMed Central

The effects of nonsaline polyethylene glycol (PEG)-6000 and saline seawater solutions of comparable osmotic potential on the concentrations of organic solutes and inorganic ions in the tissues of halophytes (Plantago maritima L., Triglochin maritima L., Limonium vulgare Mill., Halimione portulacoides (L.) Aell) have been investigated. Studies were made to determine whether high salinities induce specific ion effects that are absent in plants grown in nonsaline solutions of comparable osmotic potential. Over-all, the responses of each species to the two different treatments (seawater or PEG) are similar; the accumulation of organic solutes (compatible osmotica) in tissues is primarily correlated with a decrease in the osmotic potential of culture solutions. Depending on the species, sorbitol, proline, reducing sugars, quaternary ammonium compounds, and ?-amino nitrogen accumulate in tissues as the water potential of the tissues falls. Within a species there are differences in the concentrations of inorganic ions and organic solutes between roots and shoots of plants grown at high salinities or at high concentrations of PEG. PMID:16661119

Jefferies, Robert L.; Rudmik, Tony; Dillon, Eva M.

1979-01-01

79

Effects of stressors on invasive and halophytic plants of New England salt marshes: A framework for predicting response to tidal restoration  

Microsoft Academic Search

Salt marsh restoration practices based on the reintroduction of tides to hydrologically-altered wetlands may be hindered by\\u000a a lack of specific knowledge regarding plant community response to environmental change. Since saltmarsh plant communities\\u000a are controlled by physical stress tolerance and competition, we conducted a field experiment that measured effects of saltwater\\u000a flooding and competitive interactions on plants as a guide

Raymond A. Konisky; David M. Burdick

2004-01-01

80

The evolution of halophytes, glycophytes and crops, and its implications for food security under saline conditions.  

PubMed

557 I. 557 II. 558 III. 561 IV. 565 V. 565 VI. 566 567 References 567 SUMMARY: The effective development of salt tolerant crops requires an understanding that the evolution of halophytes, glycophytes and our major grain crops has involved significantly different processes. Halophytes (and other edaphic endemics) generally arose through colonization of habitats in severe disequilibrium by pre-adapted individuals, rather than by gradual adaptation from populations of 'glycophytes'. Glycophytes, by contrast, occur in low sodium ecosystems, where sodium was and is the major limiting nutrient in herbivore diets, suggesting that their evolution reflects the fact that low sodium individuals experienced lower herbivory and had higher fitness. For domestication/evolution of crop plants, the selective pressure was human imposed and involved humans co-opting functions of defense and reproductive security. Unintended consequences of this included loss of tolerance to various stresses and loss of the genetic variability needed to correct that. Understanding, combining and manipulating all three modes of evolution are now critical to the development of salt tolerant crops, particularly those that will offer food security in countries with few economic resources and limited infrastructure. Such efforts will require exploiting the genetic structures of recently evolved halophytes, the genetic variability of model plants, and endemic halophytes and 'minor' crops that already exist. PMID:25495078

Cheeseman, John M

2015-04-01

81

Two Cladonia Lichen Species Among Blueberry Plants  

USGS Multimedia Gallery

Two Cladonia lichen species, C. stellaris and C. rangiferina are pictured here among some blueberry plants in Newfoundland.  Lichens -- which are often mistaken for moss -- are unusual plant-like organisms that are actually symbioses of fungi, algae and bacteria living together. They usually li...

82

Atmospheric and Soil Carbon and Halophytes  

NASA Technical Reports Server (NTRS)

World population is anticipated to grow 40% within 40-50 years (2008 baseline) with unprecedented demands for energy, food, freshwater, and clean environments. At 43% of the total landmass, exploiting the Earth's arid and semi-arid lands becomes a matter of necessity. Compared with glycophyte agriculture, we view seawater and brackish water halophyte saline agriculture in its nascent stage and see the need to explore and farm on a massive scale. Halophyte farming costs should be the same as glycophyte cellulosic biomass farming; processing for cellulosic matter should also be applicable. Halophyte life cycle analyses (LCA) within the fueling debate are incomplete, yet glycophyte LCA favors biomass fueling. The Biomass Revolution is in progress. The capacity, cost, and logistics required for biomass replacement of petroleum-based fuels, however, will require all feedstock sources and regional cooperative productivity, technical investments, and both the participation and cooperation of the American farmer and global farm community.

Hendricks, Robert C.; Bushnell, Dennis M.

2011-01-01

83

Atmospheric and Soil Carbon and Halophytes  

NASA Technical Reports Server (NTRS)

World population is anticipated to grow 40% within 40-50 years with unprecedented demands for energy, food, freshwater, and clean environments. At 43% of the total landmass, exploiting the Earth s arid and semi-arid lands becomes a matter of necessity. Compared with glycophyte agriculture, we view seawater and brackish water halophyte saline agriculture in its nascent stage and see the need to explore and farm on a massive scale. Halophyte farming costs should be the same as glycophyte cellulosic biomass farming; processing for cellulosic matter should also be applicable. Halophyte life cycle analyses (LCA) within the fueling debate are incomplete, yet glycophyte LCA favors biomass fueling. The Biomass Revolution is in progress. The capacity, cost, and logistics required for biomass replacement of petroleum-based fuels, however, will require all feedstock sources and regional cooperative productivity, technical investments, and both the participation and cooperation of the American farmer and global farm community

Hendricks, Robert C.; Bushnell, Dennis M.

2010-01-01

84

Biodiversity hotspots house most undiscovered plant species  

PubMed Central

For most organisms, the number of described species considerably underestimates how many exist. This is itself a problem and causes secondary complications given present high rates of species extinction. Known numbers of flowering plants form the basis of biodiversity “hotspots”—places where high levels of endemism and habitat loss coincide to produce high extinction rates. How different would conservation priorities be if the catalog were complete? Approximately 15% more species of flowering plant are likely still undiscovered. They are almost certainly rare, and depending on where they live, suffer high risks of extinction from habitat loss and global climate disruption. By using a model that incorporates taxonomic effort over time, regions predicted to contain large numbers of undiscovered species are already conservation priorities. Our results leave global conservation priorities more or less intact, but suggest considerably higher levels of species imperilment than previously acknowledged. PMID:21730155

Joppa, Lucas N.; Roberts, David L.; Myers, Norman; Pimm, Stuart L.

2011-01-01

85

Species interaction mechanisms maintain grassland plant species diversity  

Technology Transfer Automated Retrieval System (TEKTRAN)

Theory has outpaced empirical research in pursuit of identifying mechanisms maintaining species diversity. Here we demonstrate how data from diversity-ecosystem functioning experiments can be used to test maintenance of diversity theory. We predict that grassland plant diversity can be maintained by...

86

Cellular Responses To Salinity Of Two Coastal Halophytes With Different Whole Plant Tolerance: Kosteletzkya Virginica (L.) Presl. And Sporobolus Virginicus (L.) Kunth  

Microsoft Academic Search

At the whole plant level, Sporobolus virginicus is more salt-tolerant than Kosteletzkya virginica. Cellular level (callus and protoplast) responses to salinity are reported here. The callus of Kosteletzkya had higher relative growth rates than Sporobolus, particularly at the highest salinity, however survival rate at 170 and 340 mM NaC1 was similar. Upon salinization, Kosteletzkya had higher cell wall digestibility and

Xianggan Li; Denise M. Seliskar; John L. Gallagher

87

Ensemble habitat mapping of invasive plant species  

USGS Publications Warehouse

Ensemble species distribution models combine the strengths of several species environmental matching models, while minimizing the weakness of any one model. Ensemble models may be particularly useful in risk analysis of recently arrived, harmful invasive species because species may not yet have spread to all suitable habitats, leaving species-environment relationships difficult to determine. We tested five individual models (logistic regression, boosted regression trees, random forest, multivariate adaptive regression splines (MARS), and maximum entropy model or Maxent) and ensemble modeling for selected nonnative plant species in Yellowstone and Grand Teton National Parks, Wyoming; Sequoia and Kings Canyon National Parks, California, and areas of interior Alaska. The models are based on field data provided by the park staffs, combined with topographic, climatic, and vegetation predictors derived from satellite data. For the four invasive plant species tested, ensemble models were the only models that ranked in the top three models for both field validation and test data. Ensemble models may be more robust than individual species-environment matching models for risk analysis. ?? 2010 Society for Risk Analysis.

Stohlgren, T.J.; Ma, P.; Kumar, S.; Rocca, M.; Morisette, J.T.; Jarnevich, C.S.; Benson, N.

2010-01-01

88

Ensemble habitat mapping of invasive plant species.  

PubMed

Ensemble species distribution models combine the strengths of several species environmental matching models, while minimizing the weakness of any one model. Ensemble models may be particularly useful in risk analysis of recently arrived, harmful invasive species because species may not yet have spread to all suitable habitats, leaving species-environment relationships difficult to determine. We tested five individual models (logistic regression, boosted regression trees, random forest, multivariate adaptive regression splines (MARS), and maximum entropy model or Maxent) and ensemble modeling for selected nonnative plant species in Yellowstone and Grand Teton National Parks, Wyoming; Sequoia and Kings Canyon National Parks, California, and areas of interior Alaska. The models are based on field data provided by the park staffs, combined with topographic, climatic, and vegetation predictors derived from satellite data. For the four invasive plant species tested, ensemble models were the only models that ranked in the top three models for both field validation and test data. Ensemble models may be more robust than individual species-environment matching models for risk analysis. PMID:20136746

Stohlgren, Thomas J; Ma, Peter; Kumar, Sunil; Rocca, Monique; Morisette, Jeffrey T; Jarnevich, Catherine S; Benson, Nate

2010-02-01

89

Evidence for electrotropism in some plant species  

NASA Astrophysics Data System (ADS)

The ever-present global Atmospheric Electrical Field (AEF) is used by many plant species. There are many natural habitats with electrotropic plants and habitats with no AEF. The plants growing there are not electrotropic, like the plants growing under the canopies of the trees or the Arecibo radio telescope. Examples are given of different plants which belong to one or the other class, and the criteria how to distinguish them. In addition to natural habitat observations, laboratory experiments were run in search of the sensitivity of electrotropic effect to different electric field intensities. During a few years, it was established that in very strong fields (of the order of 1 MV/m) all plants respond immediately to the field. This type of reaction is due to the Coulomb forces, but electrotropism depends on electric field interaction with ions. The "reference field" (130 V/m) was always used with stronger fields in the several kV/m range which enhance plant growth rate and size similar to plant growth hormones. Surprising effects were also observed with reversed and horizontal field polarity. In conclusion electrotropic plants deprived of the electrical field do not develop as expected, as can be seen in Biosphere 2. This is an instructive example of what happens when we forget to provide the plants with this vital natural environmental factor. Electrical fields of different intensity, directions and configurations are cheap and easy to generate.

Gorgolewski, S.; Ro?ej, B.

2001-01-01

90

Evidence for electrotropism in some plant species.  

PubMed

The ever-present global Atmospheric Electrical Field (AEF) is used by many plant species. There are many natural habitats with electrotropic plants and habitats with no AEF. The plants growing there are not electrotropic, like the plants growing under the canopies of the trees or the Arecibo radio telescope. Examples are given of different plants which belong to one or the other class, and the criteria how to distinguish them. In addition to natural habitat observations, laboratory experiments were run in search of the sensitivity of electrotropic effect to different electric field intensities. During a few years, it was established that in very strong fields (of the order of 1 MV/m) all plants respond immediately to the field. This type of reaction is due to the Coulomb forces, but electrotropism depends on electric field interaction with ions. The "reference field" (130 V/m) was always used with stronger fields in the several kV/m range which enhance plant growth rate and size similar to plant growth hormones. Surprising effects were also observed with reversed and horizontal field polarity. In conclusion electrotropic plants deprived of the electrical field do not develop as expected, as can be seen in Biosphere 2. This is an instructive example of what happens when we forget to provide the plants with this vital natural environmental factor. Electrical fields of different intensity, directions and configurations are cheap and easy to generate. PMID:11803965

Gorgolewski, S; Rozej, B

2001-01-01

91

Effects of salinity and ascorbic acid on growth, water status and antioxidant system in a perennial halophyte.  

PubMed

Salinity causes oxidative stress in plants by enhancing production of reactive oxygen species, so that an efficient antioxidant system, of which ascorbic acid (AsA) is a key component, is an essential requirement of tolerance. However, antioxidant responses of plants to salinity vary considerably among species. Limonium stocksii is a sub-tropical halophyte found in the coastal marshes from Gujarat (India) to Karachi (Pakistan) but little information exists on its salt resistance. In order to investigate the role of AsA in tolerance, 2-month-old plants were treated with 0 (control), 300 (moderate) and 600 (high) mM NaCl for 30 days with or without exogenous application of AsA (20 mM) or distilled water. Shoot growth of unsprayed plants at moderate salinity was similar to that of controls while at high salinity growth was inhibited substantially. Sap osmolality, AsA concentrations and activities of AsA-dependant antioxidant enzymes increased with increasing salinity. Water spray resulted in some improvement in growth, indicating that the growth promotion by exogenous treatments could partly be attributed to water. However, exogenous application of AsA on plants grown under saline conditions improved growth and AsA dependent antioxidant enzymes more than the water control treatment. Our data show that AsA-dependent antioxidant enzymes play an important role in salinity tolerance of L. stocksii. PMID:25603966

Hameed, Abdul; Gulzar, Salman; Aziz, Irfan; Hussain, Tabassum; Gul, Bilquees; Khan, M Ajmal

2015-01-01

92

Screening of 18 species for digestate phytodepuration.  

PubMed

This experiment assesses the aptitude of 18 species in treating the digestate liquid fraction (DLF) in a floating wetland treatment system. The pilot system was created in NE Italy in 2010 and consists of a surface-flow system with 180 floating elements (Tech-IA®) vegetated with ten halophytes and eight other wetland species. The species were transplanted in July 2011 in basins filled with different proportions of DLF/water (DLF/w); periodic increasing of the DLF/w ratio was imposed after transplanting, reaching the worst conditions for plants in summer 2012 (highest EC value 7.3 mS cm/L and NH4-N content 225 mg/L). It emerged that only Cynodon dactylon, Typha latifolia, Elytrigia atherica, Halimione portulacoides, Salicornia fruticosa, Artemisia caerulescens, Spartina maritima and Puccinellia palustris were able to survive under the system conditions. Halophytes showed higher dry matter production than other plants. The best root development (up to 40-cm depth) was recorded for Calamagrostis epigejos, Phragmites australis, T. latifolia and Juncus maritimus. The highest nitrogen (10-15 g/m(2)) and phosphorus (1-4 g/m(2)) uptakes were obtained with P. palustris, Iris pseudacorus and Aster tripolium. In conclusion, two halophytes, P. palustris and E. atherica, present the highest potential to be used to treat DLF in floating wetlands. PMID:25005162

Pavan, Francesca; Breschigliaro, Simone; Borin, Maurizio

2015-02-01

93

How does NaCl improve tolerance to cadmium in the halophyte Sesuvium portulacastrum?  

PubMed

Sesuvium portulacastrum is a halophyte with considerable Cd tolerance and accumulation, especially under high salinity. The species seems a good candidate for phytoremediation of Cd-contaminated, saline soils. However, the mechanisms sustaining salt-induced alleviation of Cd toxicity remain unknown. Seedlings of S. portulacastrum were submitted hydroponically to different Cd concentrations (0, 25 and 50 ?M Cd) in combination with low (0.09 mM), or high (200 mM) NaCl. Cadmium distribution within leaves and stems was assessed by total Cd, cell sap Cd, and Cd in different cell fractions. In plants with low salt supply (LS) Cd induced severe toxicity. The presence of 200 mM NaCl (HS) significantly alleviated Cd toxicity symptoms. HS drastically reduced both Cd-induced H2O2 production and membrane damage. In HS plants the reduced Cd uptake was only in part responsible for the lower Cd toxicity. Even at equal internal leaf Cd concentrations less Cd toxicity was observed in HS than in LS plants. In HS plants proportionally more Cd was bound in cell walls and proportionally less accumulated in the soluble fraction than in LS plants. Our results show that NaCl improves plant performance under Cd stress by both a decrease of Cd(2+) activity in the medium leading to less Cd uptake and a change of Cd speciation and compartmentation inside tissues. More efficient internal detoxification seems mainly brought about by preferential Cd binding to chloride and cell walls in plants treated with a high salt concentration. PMID:25104648

Mariem, Wali; Kilani, Ben Rjab; Benet, Gunsé; Abdelbasset, Lakdhar; Stanley, Lutts; Charlotte, Poschenrieder; Chedly, Abdelly; Tahar, Ghnaya

2014-12-01

94

Heterogeneous distribution of metabolites across plant species  

E-print Network

We investigate the distribution of flavonoid, a major category of plant secondary metabolites, across species. Flavonoid is known to show high species specificity, and was once considered as a chemical marker to understand adaptive evolution and characterization of living organisms. We investigate the distribution among species using bipartite networks, and find that two heterogeneous distributions are conserved between several families: the power law distributions of the number of flavonoids in a species and the number of shared species of a particular flavonoid. In order to explain the possible origin of the heterogeneity, we propose a simple model with, essentially, a single parameter. As a result, we show that two respective power-law statistics emerge from simple evolutionary mechanisms based on a multiplicative process. These findings provide insights into the evolution of metabolite diversity and characterization of living organisms that defy genome sequence analysis for different reasons.

Takemoto, Kazuhiro

2009-01-01

95

Heterogeneous distribution of metabolites across plant species  

NASA Astrophysics Data System (ADS)

We investigate the distribution of flavonoids, a major category of plant secondary metabolites, across species. Flavonoids are known to show high species specificity, and were once considered as chemical markers for understanding adaptive evolution and characterization of living organisms. We investigate the distribution among species using bipartite networks, and find that two heterogeneous distributions are conserved among several families: the power-law distributions of the number of flavonoids in a species and the number of shared species of a particular flavonoid. In order to explain the possible origin of the heterogeneity, we propose a simple model with, essentially, a single parameter. As a result, we show that two respective power-law statistics emerge from simple evolutionary mechanisms based on a multiplicative process. These findings provide insights into the evolution of metabolite diversity and characterization of living organisms that defy genome sequence analysis for different reasons.

Takemoto, Kazuhiro; Arita, Masanori

2009-07-01

96

Effects of crab halophytic plant interactions on creek growth in a S.W. Atlantic salt marsh: A Cellular Automata model  

NASA Astrophysics Data System (ADS)

The Bahía Blanca Estuary (38° 50' S, and 62° 30' W) presents salt marshes where interactions between the local flora ( Sarcocornia perennis) and fauna ( Chasmagnathus granulatus) generate some kind of salt pans that alter the normal water circulation and condition its flow and course towards tidal creeks. The crab-vegetation dynamics in the salt marsh presents variations that cannot be quantified in a reasonable period of time. The interaction between S. perennis plant and C. granulatus crab is based on simple laws, but its result is a complex biological mechanism that causes an erosive process on the salt marsh and favors the formation of tidal creeks. To study it, a Cellular Automata model is proposed, based on the laws deduced from the observation of these phenomena in the field, and then verified with measurable data within macroscale time units. Therefore, the objective of this article is to model how the interaction between C. granulatus and S. perennis modifies the landscape of the salt marsh and influences the path of tidal creeks. The model copies the basic laws that rule the problem based on purely biological factors. The Cellular Automata model proved capable of reproducing the effects of the interaction between plants and crabs in the salt marsh. A study of the water drainage of the basins showed that this interaction does indeed modify the development of tidal creeks. Model dynamics would likewise follow different laws, which would provide a different formula for the probability of patch dilation. The patch shape can be obtained changing the pattern that dilates.

Minkoff, Darío R.; Escapa, Mauricio; Ferramola, Félix E.; Maraschín, Silvio D.; Pierini, Jorge O.; Perillo, Gerardo M. E.; Delrieux, Claudio

2006-09-01

97

Understanding local and regional plant diversity: species pools, species saturation, and the multi-scalar effects of plant productivity  

E-print Network

Understanding local and regional plant diversity: species pools, species saturation, and the multi ABSTRACT Joel M. Gramling: Understanding local and regional plant diversity: species pools, species) The different patterns of plant species diversity that occur at local to regional scales are examined across

Peet, Robert K.

98

Aster tripolium L. and Sesuvium portulacastrum L.: two halophytes, two strategies to survive in saline habitats.  

PubMed

Aster tripolium L. (Dollart, Germany) and Sesuvium portulacastrum L. (Dakhla, Morocco) are potential halophytic vegetables, fodder plants, and ornamentals for re-vegetating saline land. To compare their strategies involved in salt tolerance both plants were grown with 0%, 1.5%, and 3% (Aster) or 0%, 2.5%, and 5% (Sesuvium) NaCl in the watering solution. The growth rate was reduced in both species with increasing NaCl concentrations. The quotient of Na(+)/K(+) indicates that Aster accumulates more K(+) in comparison to Na(+) while the reverse is true for Sesuvium. Osmolality of the leaf sap increased with increasing NaCl concentration in both Aster and Sesuvium. Transpiration rate was severely reduced in both Aster (3%) and Sesuvium (5%) plants after 10 d of NaCl watering. The CO(2) assimilation rate decreased in Aster (3%) and Sesuvium (5%) NaCl-treated plants from day 5 to day 10. The most important results from chlorophyll fluorescence measurements were derived from the non-photochemical quenching analysis (NPQ). First, both plants had linearly increasing levels of NPQ with increasing NaCl concentrations. Second, Sesuvium had almost half the NPQ value when compared to Aster under increased soil salinity. In Aster P-ATPase activities were decreased in plants treated with 3% NaCl after three days of treatment, F-ATPase activities increased with increasing NaCl concentrations and no clear changes were measured in V-ATPase activities. In Sesuvium any changes could be observed in the three ATPase activities determined. To conclude, Aster and Sesuvium use different strategies in adaptation to soil salinity. PMID:16806957

Ramani, Balasubramanian; Reeck, Thilo; Debez, Ahmed; Stelzer, Ralf; Huchzermeyer, Bernhard; Schmidt, Ahlert; Papenbrock, Jutta

2006-01-01

99

Plant species evaluated for new crop potential  

SciTech Connect

Ninety-two plant species from various regions of the USA were screened for their energy-producing potential. Samples were analysed for oil, polyphenol, hydrocarbon and protein. Oil fractions of some species were analysed for classes of lipid constituents and yields of unsaponifiable matter and fatty acids were determined. Hydrocarbon fractions of some species were analysed for rubber, gutta and waxes. Average MW and MW distribution of rubber and gutta were determined. Complete analytical data for 16 species is presented. Large quantities of oil were obtained from Philadelphus coronarius, Cacalia muhlenbergii, Lindera benzoin and Koelreuteria paniculata. High yields of polyphenols came from Acer ginnala, Cornus obliqua and Salix caprea and maximum yields of hydrocarbon and protein were from Elymus virginicus and Lindera benzoin, respectively.

Carr, M.E.

1985-01-01

100

Comparative Genomics in Salt Tolerance between Arabidopsis and Arabidopsis-Related Halophyte Salt Cress Using Arabidopsis Microarray  

Microsoft Academic Search

Salt cress (Thellungiella halophila), a halophyte, is a genetic model system with a small plant size, short life cycle, copious seed production, small genome size, and an efficient transformation. Its genes have a high sequence identity (90%-95% at cDNA level) to genes of its close relative, Arabidopsis. These qualities are advantageous not only in genetics but also in genomics, such

Teruaki Taji; Motoaki Seki; Masakazu Satou; Tetsuya Sakurai; Masatomo Kobayashi; Kanako Ishiyama; Yoshihiro Narusaka; Mari Narusaka; Jian-Kang Zhu; Kazuo Shinozaki

2004-01-01

101

Compound leaf development in model plant species.  

PubMed

Plant leaves develop in accordance with a common basic program, which is flexibly adjusted to the species, developmental stage and environment. Two key stages of leaf development are morphogenesis and differentiation. In the case of compound leaves, the morphogenesis stage is prolonged as compared to simple leaves, allowing for the initiation of leaflets. Here, we review recent advances in the understanding of how plant hormones and transcriptional regulators modulate compound leaf development, yielding a substantial diversity of leaf forms, focusing on four model compound leaf organisms: cardamine (Cardamine hirsuta), tomato (Solanum lycopersicum), medicago (Medicago truncatula) and pea (Pisum sativum). PMID:25449728

Bar, Maya; Ori, Naomi

2015-02-01

102

Biophysical and biochemical constraints imposed by salt stress: learning from halophytes  

PubMed Central

Soil salinization is one of the most important factors impacting plant productivity. About 3.6 billion of the world’s 5.2 billion ha of agricultural dry land, have already suffered erosion, degradation, and salinization. Halophytes are typically considered as plants able to complete their life cycle in environments where the salt concentration is above 200 mM NaCl. Salinity adjustment is a complex phenomenon but essential mechanism to overcome salt stress, with both biophysical and biochemical implications. At this level, halophytes evolved in several directions, adopting different strategies. Otherwise, the lack of adaptation to a salt environment would negatively affect their electron transduction pathways and the entire energetic metabolism, the foundation of every plant photosynthesis and biomass production. The maintenance of ionic homeostasis is in the basis of all cellular counteractive measures, in particular in terms of redox potential and energy transduction. In the present work the biophysical mechanisms underlying energy capture and transduction in halophytes are discussed alongside with their relation with biochemical counteractive mechanisms, integrating data from photosynthetic light harvesting complexes, electron transport chains to the quinone pools, carbon fixation, and energy dissipation metabolism. PMID:25566311

Duarte, Bernardo; Sleimi, Noomene; Caçador, Isabel

2014-01-01

103

Plant Species Intermediate for C3, C4 Photosynthesis  

Microsoft Academic Search

Mollugo verticillata is the first plant species reported which has characteristics of both C3 (Calvin-Benson pathway) and C4 (Hatch-Slack pathway) plants. This plant species is intermediate between C3 and C4 plants in at least four features generally used to separate those two plant groups: leaf anatomy, cell ultrastructure, photorespiration, and primary photosynthetic products.

R. A. Kennedy; W. M. Laetsch

1974-01-01

104

Plant species intermediate for c3, c4 photosynthesis.  

PubMed

Mollugo verticillata is the first plant species reported which has characteristics of both C(3) (Calvin-Benson pathway) and C(4) (Hatch-Slack pathway) plants. This plant species is intermediate between C(3) and C(4) plants in at least four features generally used to separate those two plant groups: leaf anatomy, cell ultrastructure, photorespiration, and primary photosynthetic products. PMID:17736195

Kennedy, R A; Laetsch, W M

1974-06-01

105

Mangroves: obligate or facultative halophytes? A review  

Microsoft Academic Search

Salinity plays significant roles in regulating the growth and distribution of mangroves, and the salt tolerance mechanisms\\u000a of mangroves have been the focus of research for several decades. There are contradictory views regarding the relationship\\u000a between mangroves and salt: (1) Mangroves are facultative halophytes, i.e. freshwater is a physiological requirement and salt\\u000a water is an ecological requirement for mangroves because

Wenqing Wang; Zhongzheng Yan; Siyang You; Yihui Zhang; Luzhen Chen; Guanghui Lin

106

Dioxin uptake by Indian plant species  

Microsoft Academic Search

Dioxins like various gaseous pollutants and aerosols can be scavenged by appropriate vegetative greenbelts. Based on their\\u000a stomatal properties and the models for contaminant uptake, uptake of dioxin (2,3,7,8-TCDD) by three important Indian plant\\u000a species, viz. Eugenia jambolana (Jamun), Azadirachta indica (Neem) and Ficus religiosa (Peepal), has been estimated. 2,3,7,8-TCDD is a contaminant with severe harmful ecological ramifications. Computations show

J. S. Pandey; R. Kumar; S. R. Wate

2008-01-01

107

Cd and Ni transport and accumulation in the halophyte Sesuvium portulacastrum: implication of organic acids in these processes.  

PubMed

The implication of organic acids in Cd and Ni translocation was studied in the halophyte species Sesuvium portulacastrum. Citric, fumaric, malic, and ascorbic acids were separated and quantified by HPLC technique in shoots, roots and xylem saps of plants grown on nutrient solutions added with 50 ?M Cd, 100 ?M Ni and the combination of 50 ?M Cd + 100 ?M Ni. Results showed that Cd had no significant impact on biomass production while Ni and the combination of both metals drastically affected plant development. Cadmium and Ni concentrations in tissues and xylem sap were higher in plants subjected to individual metal application than those subjected to the combined effect of Cd and Ni suggesting a possible competition between these metals for absorption. Both metals applied separately or in combination induced an increase in citrate concentration in shoots and xylem sap but a decrease of this concentration in the roots. However, a minor relationship was observed between metal application and fumaric, malic, and ascorbic acids. Both observations suggest the implication of citric acid in Cd, Ni translocation and shoot accumulation in S. portulacastrum. The relatively high accumulation of citric acid in xylem sap and shoot of S. portulacastrum could be involved in metal chelation and thus contributes to heavy metal tolerance in this species. PMID:25821455

Mnasri, Mejda; Ghabriche, Rim; Fourati, Emna; Zaier, Hanen; Sabally, Kebba; Barrington, Suzelle; Lutts, Stanley; Abdelly, Chedly; Ghnaya, Tahar

2015-01-01

108

Cd and Ni transport and accumulation in the halophyte Sesuvium portulacastrum: implication of organic acids in these processes  

PubMed Central

The implication of organic acids in Cd and Ni translocation was studied in the halophyte species Sesuvium portulacastrum. Citric, fumaric, malic, and ascorbic acids were separated and quantified by HPLC technique in shoots, roots and xylem saps of plants grown on nutrient solutions added with 50 ?M Cd, 100 ?M Ni and the combination of 50 ?M Cd + 100 ?M Ni. Results showed that Cd had no significant impact on biomass production while Ni and the combination of both metals drastically affected plant development. Cadmium and Ni concentrations in tissues and xylem sap were higher in plants subjected to individual metal application than those subjected to the combined effect of Cd and Ni suggesting a possible competition between these metals for absorption. Both metals applied separately or in combination induced an increase in citrate concentration in shoots and xylem sap but a decrease of this concentration in the roots. However, a minor relationship was observed between metal application and fumaric, malic, and ascorbic acids. Both observations suggest the implication of citric acid in Cd, Ni translocation and shoot accumulation in S. portulacastrum. The relatively high accumulation of citric acid in xylem sap and shoot of S. portulacastrum could be involved in metal chelation and thus contributes to heavy metal tolerance in this species.

Mnasri, Mejda; Ghabriche, Rim; Fourati, Emna; Zaier, Hanen; Sabally, Kebba; Barrington, Suzelle; Lutts, Stanley; Abdelly, Chedly; Ghnaya, Tahar

2015-01-01

109

RESPONSE OF WETLAND PLANT SPECIES TO HYDROLOGIC CONDITIONS  

EPA Science Inventory

Understanding hydrologic requirements of native and introduced species is critical to sustaining native plant communities in wetlands of disturbed landscapes. We examined plant assemblages and 31 species from emergent wetlands in an urbanizing area of the Pacific Northwest, USA,...

110

RESPONSE OF WETLAND PLANT SPECIES TO HYDROLOGIC CONDITIONS  

EPA Science Inventory

Understanding hydrologic requirements of native and introduced species is critical to sustaining native plant communities in wetlands of disturbed landscapes. We examined plant assemblages and 31 species from emergent wetlands in an urbanizing area of the Pacific Northwest, USA, ...

111

Physiological responses of a halophytic shrub to salt stress by Na2SO4 and NaCl: oxidative damage and the role of polyphenols in antioxidant protection.  

PubMed

Salt stress conditions lead to increased production of reactive oxygen species (ROS) in plant cells. Halophytes have the ability to reduce these toxic ROS by means of a powerful antioxidant system that includes enzymatic and non-enzymatic components. In this research, we used the halophytic shrub Prosopis strombulifera to investigate whether the ability of this species to grow under increasing salt concentrations and mixtures was related to the synthesis of polyphenolic compounds and to the maintenance of leaf pigment contents for an adequate photosynthetic activity. Seedlings of P. strombulifera were grown hydroponically in Hoagland's solution, gradually adding Na2SO4 and NaCl separately or in mixtures until reaching final osmotic potentials of -1, -1.9 and -2.6 MPa. Control plants were allowed to develop in Hoagland's solution without salt. Oxidative damage in tissues was determined by H2O2 and malondialdehyde content. Leaf pigment analysis was performed by high-performance liquid chromatography with ultraviolet, and total phenols, total flavonoids, total flavan-3-ols, condensed tannins, tartaric acid esters and flavonols were spectrophotometrically assayed. Treatment with Na2SO4 increased H2O2 production and lipid peroxidation in tissues and induced a sharp increase in flavonoid compounds (mainly flavan-3-ols) and consequently in the antioxidant activity. Also, Na2SO4 treatment induced an increased carotenoid/chlorophyll ratio, which may represent a strategy to protect photosystems against photooxidation. NaCl treatment, however, did not affect H2O2 content, lipid peroxidation, pigments or polyphenols synthesis. The significant accumulation of flavonoids in tissues under Na2SO4 treatment and their powerful antioxidant activity indicates a role for these compounds in counteracting the oxidative damage induced by severe salt stress, particularly, ionic stress. We demonstrate that ionic interactions between different salts in salinized soils modify the biochemical and morpho-physiological responses of P. strombulifera plants to salinity. PMID:25063834

Reginato, Mariana A; Castagna, Antonella; Furlán, Ana; Castro, Stella; Ranieri, Annamaria; Luna, Virginia

2014-01-01

112

Physiological responses of a halophytic shrub to salt stress by Na2SO4 and NaCl: oxidative damage and the role of polyphenols in antioxidant protection  

PubMed Central

Salt stress conditions lead to increased production of reactive oxygen species (ROS) in plant cells. Halophytes have the ability to reduce these toxic ROS by means of a powerful antioxidant system that includes enzymatic and non-enzymatic components. In this research, we used the halophytic shrub Prosopis strombulifera to investigate whether the ability of this species to grow under increasing salt concentrations and mixtures was related to the synthesis of polyphenolic compounds and to the maintenance of leaf pigment contents for an adequate photosynthetic activity. Seedlings of P. strombulifera were grown hydroponically in Hoagland's solution, gradually adding Na2SO4 and NaCl separately or in mixtures until reaching final osmotic potentials of ?1, ?1.9 and ?2.6 MPa. Control plants were allowed to develop in Hoagland's solution without salt. Oxidative damage in tissues was determined by H2O2 and malondialdehyde content. Leaf pigment analysis was performed by high-performance liquid chromatography with ultraviolet, and total phenols, total flavonoids, total flavan-3-ols, condensed tannins, tartaric acid esters and flavonols were spectrophotometrically assayed. Treatment with Na2SO4 increased H2O2 production and lipid peroxidation in tissues and induced a sharp increase in flavonoid compounds (mainly flavan-3-ols) and consequently in the antioxidant activity. Also, Na2SO4 treatment induced an increased carotenoid/chlorophyll ratio, which may represent a strategy to protect photosystems against photooxidation. NaCl treatment, however, did not affect H2O2 content, lipid peroxidation, pigments or polyphenols synthesis. The significant accumulation of flavonoids in tissues under Na2SO4 treatment and their powerful antioxidant activity indicates a role for these compounds in counteracting the oxidative damage induced by severe salt stress, particularly, ionic stress. We demonstrate that ionic interactions between different salts in salinized soils modify the biochemical and morpho-physiological responses of P. strombulifera plants to salinity. PMID:25063834

Reginato, Mariana A.; Castagna, Antonella; Furlán, Ana; Castro, Stella; Ranieri, Annamaria; Luna, Virginia

2014-01-01

113

Effects of salinity on flowering, morphology, biomass accumulation and leaf metabolites in an edible halophyte  

PubMed Central

The fresh water shortage in agriculture is an increasing problem worldwide, therefore the possibility of cultivating crops under saline conditions is of high importance. Crithmum maritimum, a halophytic plant naturally found on the rocky coastlines of the Atlantic Ocean and the Mediterranean Sea, has a long history of human consumption and was recently suggested as a cash crop for biosaline agriculture. In the present study, we compared the responses of different genotypes originating from France, Portugal and Israel to moderate saline irrigation (up to 100 mM NaCl). The genotypes varied greatly in the onset of flowering, their leaf appearance, growth habits and leaf metabolite content. Both Atlantic genotypes (from France and Portugal) flowered earlier than those from the Mediterranean, but the number of inflorescences decreased with salinity. Irrigation with 50 and 100 mM NaCl led to a reduction in biomass production in both the Israeli and the Portuguese genotypes, while the French genotype was found to produce maximum leaf yield at 50 mM NaCl. With increasing salinity, salt was accumulated by the plants, as indicated by increasing electrical conductivities of the leaf extracts. Concomitantly, antioxidant compounds (such as ascorbic acid), total polyphenols and ureides responded to salinity in a genotype-dependent manner; either they increased, decreased or were unaffected. Notably, the total fatty acid concentration increased with salinity in both Mediterranean genotypes, reaching 2.7 and 2.4 % total fatty acids (on a dry weight basis) at 100 mM NaCl. Moreover, the proportion assigned to omega-3 fatty acids in these genotypes was higher than in their Atlantic counterparts at the highest salinity tested. Our results highlight the variations existing among C. maritimum genotypes from different origins regarding salt-induced changes in plant growth, flowering behaviour and leaf metabolites with nutritional value. Thus, genotypic characteristics should be taken into account when evaluating a wild plant species for future crop cultivation. PMID:25178274

Ventura, Yvonne; Myrzabayeva, Malika; Alikulov, Zerekbay; Omarov, Rustem; Khozin-Goldberg, Inna; Sagi, Moshe

2014-01-01

114

Effects of salinity on flowering, morphology, biomass accumulation and leaf metabolites in an edible halophyte.  

PubMed

The fresh water shortage in agriculture is an increasing problem worldwide, therefore the possibility of cultivating crops under saline conditions is of high importance. Crithmum maritimum, a halophytic plant naturally found on the rocky coastlines of the Atlantic Ocean and the Mediterranean Sea, has a long history of human consumption and was recently suggested as a cash crop for biosaline agriculture. In the present study, we compared the responses of different genotypes originating from France, Portugal and Israel to moderate saline irrigation (up to 100 mM NaCl). The genotypes varied greatly in the onset of flowering, their leaf appearance, growth habits and leaf metabolite content. Both Atlantic genotypes (from France and Portugal) flowered earlier than those from the Mediterranean, but the number of inflorescences decreased with salinity. Irrigation with 50 and 100 mM NaCl led to a reduction in biomass production in both the Israeli and the Portuguese genotypes, while the French genotype was found to produce maximum leaf yield at 50 mM NaCl. With increasing salinity, salt was accumulated by the plants, as indicated by increasing electrical conductivities of the leaf extracts. Concomitantly, antioxidant compounds (such as ascorbic acid), total polyphenols and ureides responded to salinity in a genotype-dependent manner; either they increased, decreased or were unaffected. Notably, the total fatty acid concentration increased with salinity in both Mediterranean genotypes, reaching 2.7 and 2.4 % total fatty acids (on a dry weight basis) at 100 mM NaCl. Moreover, the proportion assigned to omega-3 fatty acids in these genotypes was higher than in their Atlantic counterparts at the highest salinity tested. Our results highlight the variations existing among C. maritimum genotypes from different origins regarding salt-induced changes in plant growth, flowering behaviour and leaf metabolites with nutritional value. Thus, genotypic characteristics should be taken into account when evaluating a wild plant species for future crop cultivation. PMID:25178274

Ventura, Yvonne; Myrzabayeva, Malika; Alikulov, Zerekbay; Omarov, Rustem; Khozin-Goldberg, Inna; Sagi, Moshe

2014-01-01

115

Genomic Basis of Plant Pathogen Suppression by Biocontrol Pseudomonas Species  

Technology Transfer Automated Retrieval System (TEKTRAN)

Various plant commensal bacterial species, which naturally colonize the plant rhizosphere, are able to suppress fungal, bacterial, viral and even insect plant pathogens. These biocontrol activities are elicited primarily through the production of secreted exoenzymes and secondary metabolites that ma...

116

Structural and Functional State of Thylakoids in a Halophyte Suaeda altissima before and after Disturbance of Salt–Water Balance by Extremely High Concentrations of NaCl  

Microsoft Academic Search

Halophyte plants Suaeda altissima L. were grown in water culture at different concentrations of NaCl in the medium, and their leaves were sampled to examine the ultrastructure of chloroplasts. In parallel tests, the functional state of chloroplasts was assessed from parameters of chlorophyll fluorescence. In addition the effects of NaCl on plant growth and on the contents of Na+, K+,

Yu. V. Balnokin; E. B. Kurkova; N. A. Myasoedov; R. V. Lun'kov; N. Z. Shamsutdinov; E. A. Egorova; N. G. Bukhov

2004-01-01

117

Learning from halophytes: physiological basis and strategies to improve abiotic stress tolerance in crops  

PubMed Central

Background Global annual losses in agricultural production from salt-affected land are in excess of US$12 billion and rising. At the same time, a significant amount of arable land is becoming lost to urban sprawl, forcing agricultural production into marginal areas. Consequently, there is a need for a major breakthrough in crop breeding for salinity tolerance. Given the limited range of genetic diversity in this trait within traditional crops, stress tolerance genes and mechanisms must be identified in extremophiles and then introduced into traditional crops. Scope and Conclusions This review argues that learning from halophytes may be a promising way of achieving this goal. The paper is focused around two central questions: what are the key physiological mechanisms conferring salinity tolerance in halophytes that can be introduced into non-halophyte crop species to improve their performance under saline conditions and what specific genes need to be targeted to achieve this goal? The specific traits that are discussed and advocated include: manipulation of trichome shape, size and density to enable their use for external Na+ sequestration; increasing the efficiency of internal Na+ sequestration in vacuoles by the orchestrated regulation of tonoplast NHX exchangers and slow and fast vacuolar channels, combined with greater cytosolic K+ retention; controlling stomata aperture and optimizing water use efficiency by reducing stomatal density; and efficient control of xylem ion loading, enabling rapid shoot osmotic adjustment while preventing prolonged Na+ transport to the shoot. PMID:24085482

Shabala, Sergey

2013-01-01

118

OIKOS 103: 4558, 2003 Plant species diversity, plant biomass and responses of the soil  

E-print Network

OIKOS 103: 45­58, 2003 Plant species diversity, plant biomass and responses of the soil community species diversity, plant biomass and responses of the soil community on abandoned land across Europe plant diversity was altered by sowing seed mixtures of mid-successional grassland species with two

Leps, Jan "Suspa"

119

Southern Wetland Flora: Field Office Guide to Plant Species  

NSDL National Science Digital Library

The US Department of Agriculture's (USDA) Soil Conservation Service branch in Fort Worth, Texas produced the Southern Wetland Flora: Field Office Guide to Plant Species. The guide contains black and white illustrations, full species descriptions (with color photographs, illustrations, and small distribution maps), illustrated glossaries, an alphabetical species list (provides common and scientific names for 300 species of vascular plants), and a key to generalized plant groups. The guide may be browsed online or downloaded in .zip format.

120

Northeast Wetland Flora: Field Office Guide to Plant Species  

NSDL National Science Digital Library

The USDA Natural Resource Conservation Service's Northeast National Technical Center in Chester, Pennsylvania produced Northeast Wetland Flora: Field Office Guide to Plant Species. The guide contains black and white illustrations, full species descriptions (with color photographs, illustrations, and small distribution maps), illustrated glossaries, an alphabetical species list (provides common and scientific names for 300 species of vascular plants), and a key to generalized plant groups. The guide may be browsed online or downloaded in .zip format.

121

Exotic plant species in the southern boreal forest of Saskatchewan  

Microsoft Academic Search

Exotic species possess abilities to harm the ecosystems they invade. This study assesses the density, frequency and cover of exotic plants in roadside right-of-ways, logged areas and wildfire sites within mixedwood sections of the southern boreal forest of Saskatchewan. A total of 23 exotic species were observed including nine species of Gramineae, seven species of Leguminosae and five species of

W. H. Sumners; O. W. Archibold

2007-01-01

122

THE INTRODUCTION OF POTENTIALLY INVASIVE ALIEN PLANT SPECIES FOR HORTICULTURAL  

E-print Network

preferences; North America Subject Terms: Invasive plants -- Social aspects. Biological invasions -- SocialTHE INTRODUCTION OF POTENTIALLY INVASIVE ALIEN PLANT SPECIES FOR HORTICULTURAL PURPOSES IN NORTH: The Introduction of Potentially Invasive Alien Plant Species for Horticultural Purposes in North America: Assessing

123

A COMPENDIUM OF PLANT SPECIES PRODUCING POLLEN TETRADS  

E-print Network

A COMPENDIUM OF PLANT SPECIES PRODUCING POLLEN TETRADS GREGORY P. COPENHAVER* Department of Biology, Chapel Hill, NC 27599 Abstract: Flowering plants shed their pollen either as single grains or in groups declines. Five hundred and eighty one plant species that produce pollen tetrads that may be useful when

Copenhaver, Gregory P.

124

Dioxin uptake by Indian plant species.  

PubMed

Dioxins like various gaseous pollutants and aerosols can be scavenged by appropriate vegetative greenbelts. Based on their stomatal properties and the models for contaminant uptake, uptake of dioxin (2,3,7,8-TCDD) by three important Indian plant species, viz. Eugenia jambolana (Jamun), Azadirachta indica (Neem) and Ficus religiosa (Peepal), has been estimated. 2,3,7,8-TCDD is a contaminant with severe harmful ecological ramifications. Computations show that Ficus religiosa has highest uptake capacity. The present exercise has its utility in designing appropriate green-belts for mitigating adverse environmental and human health impacts due to dioxins. This can be an effective management option for mitigating the damages caused by dioxins. PMID:17874332

Pandey, J S; Kumar, R; Wate, S R

2008-08-01

125

New pasture plants intensify invasive species risk.  

PubMed

Agricultural intensification is critical to meet global food demand, but intensification threatens native species and degrades ecosystems. Sustainable intensification (SI) is heralded as a new approach for enabling growth in agriculture while minimizing environmental impacts. However, the SI literature has overlooked a major environmental risk. Using data from eight countries on six continents, we show that few governments regulate conventionally bred pasture taxa to limit threats to natural areas, even though most agribusinesses promote taxa with substantial weed risk. New pasture taxa (including species, subspecies, varieties, cultivars, and plant-endophyte combinations) are bred with characteristics typical of invasive species and environmental weeds. By introducing novel genetic and endophyte variation, pasture taxa are imbued with additional capacity for invasion and environmental impact. New strategies to prevent future problems are urgently needed. We highlight opportunities for researchers, agribusiness, and consumers to reduce environmental risks associated with new pasture taxa. We also emphasize four main approaches that governments could consider as they build new policies to limit weed risks, including (i) national lists of taxa that are prohibited based on environmental risk; (ii) a weed risk assessment for all new taxa; (iii) a program to rapidly detect and control new taxa that invade natural areas; and (iv) the polluter-pays principle, so that if a taxon becomes an environmental weed, industry pays for its management. There is mounting pressure to increase livestock production. With foresight and planning, growth in agriculture can be achieved sustainably provided that the scope of SI expands to encompass environmental weed risks. PMID:25368175

Driscoll, Don A; Catford, Jane A; Barney, Jacob N; Hulme, Philip E; Inderjit; Martin, Tara G; Pauchard, Aníbal; Pyšek, Petr; Richardson, David M; Riley, Sophie; Visser, Vernon

2014-11-18

126

Plant Species Recovery on a Compacted Skid Road  

PubMed Central

This study was executed to determine the plant species of herbaceous cover in a skid road subjected to soil compaction due to timber skidding in a beech (Fagus orientalis Lipsky.) stand. Our previous studies have shown that ground based timber skidding destroys the soils extremely, and degradations on ecosystem because of the timber skidding limit recovery and growth of plant cover on skid roads. However, some plant species show healthy habitat, recovery and they can survive after the extreme degradation in study area. We evaluated composition of these plant species and their cover-abundance scales in 100 m x 3 m transect. 15 plant species were determined belongs to 12 plant families and Liliaceae was the highest representative plant family. Smilax aspera L., Epimedium pubigerum (DC.) Moren et Decaisne, Carex distachya Desf. var. distachya Desf., Pteridium aquilinum (L.) Kuhn., Trachystemon orientalis (L.) G. Don, Hedera helix L. have the highest cover-abundance scale overall of determined species on compacted skid road.

Demir, Murat; Makineci, Ender; Gungor, Beyza Sat

2008-01-01

127

Halophytes of Pakistan: characteristics, distribution and potential economic usages  

Microsoft Academic Search

Fresh water resources are becoming increasingly limited and agricultural irrigation systems will steadily increase in salinity\\u000a in the near future. The time has come to develop sustainable biological production systems that can use low quality saline\\u000a water for irrigation of halophytic crops in saline lands. A large number of halophytes could be used as cash crop (forage,\\u000a fodder, fuel, medicine,

M. Ajmal Khan; M. Qaiser

128

TREE PLANTING SITE EVALUATION FORM "SITE DICTATES SPECIES"  

E-print Network

TREE PLANTING SITE EVALUATION FORM "SITE DICTATES SPECIES" ABOVE GROUND Utilities: Electric issue) Parking proximity: Distance from car doors __________________ Wind: Problem _________ No problem:________________________________________________ Fire hydrant: ________________________________________________ Electric

129

Phytophthora Species, New Threats to the Plant Health in Korea  

PubMed Central

Given the lack of a resistant genetic pool in host plants, the introduction of exotic invasive pathogens can result in epidemics that affect a specific ecosystem and economy. Plant quarantine, which is designed to protect endemic plant resources, is a highly invaluable safeguard that should keep biosecurity with increasing international trade and global transportation. A total of 34 species of plant pathogens including Phytophthora infestans were documented as introduced from other countries into Korea from 1900 to 2010. The genus Phytophthora, classified in oomycetes, includes more than 120 species that are mostly recognized worldwide as highly invasive plant pathogens. After 2000, over 50 new species of Phytophthora were identified internationally as plant pathogens occurring in crops and forest trees. In Korea, Phytophthora is also one of the most serious plant pathogens. To date, 22 species (about one-fifth of known species) of the genus have been identified and reported as plant pathogens in the country. The likelihood of new exotic Phytophthora species being introduced into Korea continues to increase, thus necessitating intensive plant quarantine inspections. As new potential threats to plant health in Korea, six Phytophthora species, namely, P. alni, P. inundata, P. kernoviae, P. pinifolia, P. quercina, and P. ramorum, are discussed in this review with focus on history, disease, biology, management, and plant quarantine issues. PMID:25506298

Hyun, Ik-Hwa; Choi, Woobong

2014-01-01

130

Phytophthora species, new threats to the plant health in Korea.  

PubMed

Given the lack of a resistant genetic pool in host plants, the introduction of exotic invasive pathogens can result in epidemics that affect a specific ecosystem and economy. Plant quarantine, which is designed to protect endemic plant resources, is a highly invaluable safeguard that should keep biosecurity with increasing international trade and global transportation. A total of 34 species of plant pathogens including Phytophthora infestans were documented as introduced from other countries into Korea from 1900 to 2010. The genus Phytophthora, classified in oomycetes, includes more than 120 species that are mostly recognized worldwide as highly invasive plant pathogens. After 2000, over 50 new species of Phytophthora were identified internationally as plant pathogens occurring in crops and forest trees. In Korea, Phytophthora is also one of the most serious plant pathogens. To date, 22 species (about one-fifth of known species) of the genus have been identified and reported as plant pathogens in the country. The likelihood of new exotic Phytophthora species being introduced into Korea continues to increase, thus necessitating intensive plant quarantine inspections. As new potential threats to plant health in Korea, six Phytophthora species, namely, P. alni, P. inundata, P. kernoviae, P. pinifolia, P. quercina, and P. ramorum, are discussed in this review with focus on history, disease, biology, management, and plant quarantine issues. PMID:25506298

Hyun, Ik-Hwa; Choi, Woobong

2014-12-01

131

A novel methyl transferase induced by osmotic stress in the facultative halophyte Mesembryanthemum crystallinum.  

PubMed Central

Molecular mechanisms of osmotic stress tolerance were studied in Mesembryanthemum crystallinum (ice plant), a facultative halophyte capable of adjusting to and surviving in highly saline conditions. We screened a subtracted cDNA library enriched for salt stress-induced mRNAs to identify transcripts involved in this plant's adaptation to salinity. One mRNA, Imt1, was found to be up-regulated in leaves and, transiently, in roots. Nuclear run-on assays indicated that this mRNA is transcriptionally regulated. Imt1 encoded a predicted polypeptide of M(r) 40,250 which exhibited sequence similarity to several hydroxymethyl transferases. Expression of the protein in Escherichia coli and subsequent activity assays identified the protein as a novel myoinositol O-methyl transferase which catalyzes the first step in the biosynthesis of the cyclic sugar alcohol pinitol. Pinitol accumulates in salt-stressed M.crystallinum and is abundant in a number of salt- and drought-tolerant plants. The presence of high levels of sugar alcohols correlates with osmotolerance in a diverse range of organisms, including bacteria, fungi and algae, as well as higher plants. The stress-initiated transcriptional induction of IMT1 expression in a facultative halophyte provides strong support for the importance of sugar alcohols in establishing tolerance to osmotic stress in higher plants. Images PMID:1600940

Vernon, D M; Bohnert, H J

1992-01-01

132

Assessment of the potential of halophytes as energy crops for the electric utility industry. Final report  

SciTech Connect

This technical report assesses and estimates the potential of selected halophytes as future renewable energy resources, especially by US electric utilities, and familiarizes nonspecialists with research and development problems that must be resolved before these energy sources can become dependable supplies of energy. A literature search related to both indigenous and exotic species of halophytes has been done and appropriate terrestrial species have been selected. Selection criteria include: total biomass potential, genetic constraints, establishment and cultivation requirements, regions of suitability, secondary credits, and a number of other factors. Based on these selection criteria, for the arid western states with high levels of salinity in water and/or soils, there is little potential for energy feedstocks derived from grasses and herbaceous forbs. Likewise, coastal marshes, estuaries, and mangrove swamps, although excellent biomass producers, are too limited by region and have too many ecological and environmental problems for consideration. The deep-rooted, perennial woody shrubs indigenous to many saline regions of the west provide the best potential. The number of species in this group is limited, and Atriplex canescens, Sarcobatus vermiculatus, and Chrysothamnus nauseosus are the three species with the greatest biological potential. These shrubs would receive minimal energy inputs in cultivation, would not compete with agricultural land, and would restore productivity to severely disturbed sites. One might logically expect to achieve biomass feedstock yields of three to five tons/acre/yr on a long-term sustainable basis. The possibility also exists that exotic species might be introduced. 67 references, 1 figure, 5 tables.

Goodin, J.R.

1984-09-01

133

Small RNA deep sequencing reveals the important role of microRNAs in the halophyte Halostachys caspica.  

PubMed

MicroRNAs (miRNAs), an extensive class of small regulatory RNAs, play versatile roles in plant growth and development as well as stress responses. However, the regulatory mechanism is unclear on miRNA-mediated response to abiotic stress in plants. Halostachys caspica is a halophytic plant species and a great model for investigating plant response to salinity stress. However, no research has been performed on miRNAs in H. caspica. In this study, we employed deep sequencing to identify both conserved and novel miRNAs from salinity-exposed H. caspica and its untreated control. Among the 13-19 million sequences generated from both treatments, a total of 170 conserved miRNAs, belonging to 151 miRNA families, were identified; among these miRNAs, 31 were significantly up-regulated and 48 were significantly down-regulated by salinity stress. We also identified 102 novel miRNAs from H. caspica; among them, 12 miRNAs were significantly up-regulated and 13 were significantly down-regulated by salinity. qRT-PCR expression analysis validated the deep sequencing results and also demonstrated that miRNAs and their targeted genes were responsive to high salt stress and existed a negative expression correlation between miRNAs and their targets. miRNA-target prediction, GO and KEGG analysis showed that miRNAs were involved in salt stress-related biological pathway, including calcium signalling pathway, MAPK signalling pathway, plant hormone signal transduction and flavonoid biosynthesis, etc. This suggests that miRNAs play an important role in plant salt stress tolerance in H. caspica. This result could be used to improve salt tolerance in crops and woods. PMID:25832169

Yang, Ruirui; Zeng, Youling; Yi, Xiaoya; Zhao, Lijuan; Zhang, Yufang

2015-04-01

134

Functional identity versus species richness: herbivory resistance in plant communities  

PubMed Central

The resistance of a plant community against herbivore attack may depend on plant species richness, with monocultures often much more severely affected than mixtures of plant species. Here, we used a plant–herbivore system to study the effects of selective herbivory on consumption resistance and recovery after herbivory in 81 experimental grassland plots. Communities were established from seed in 2002 and contained 1, 2, 4, 8, 16 or 60 plant species of 1, 2, 3 or 4 functional groups. In 2004, pairs of enclosure cages (1 m tall, 0.5 m diameter) were set up on all 81 plots. One randomly selected cage of each pair was stocked with 10 male and 10 female nymphs of the meadow grasshopper, Chorthippus parallelus. The grasshoppers fed for 2 months, and the vegetation was monitored over 1 year. Consumption resistance and recovery of vegetation were calculated as proportional changes in vegetation biomass. Overall, grasshopper herbivory averaged 6.8%. Herbivory resistance and recovery were influenced by plant functional group identity, but independent of plant species richness and number of functional groups. However, herbivory induced shifts in vegetation composition that depended on plant species richness. Grasshopper herbivory led to increases in herb cover at the expense of grasses. Herb cover increased more strongly in species-rich mixtures. We conclude that selective herbivory changes the functional composition of plant communities and that compositional changes due to selective herbivory depend on plant species richness. PMID:20429014

Heimann, Juliane; Köhler, Günter; Mitschunas, Nadine; Weisser, Wolfgang W.

2010-01-01

135

Soil organisms shape the competition between grassland plant species.  

PubMed

Decomposers and arbuscular mycorrhizal fungi (AMF) both determine plant nutrition; however, little is known about their interactive effects on plant communities. We set up a greenhouse experiment to study effects of plant competition (one- and two-species treatments), Collembola (Heteromurus nitidus and Protaphorura armata), and AMF (Glomus intraradices) on the performance (above- and belowground productivity and nutrient uptake) of three grassland plant species (Lolium perenne, Trifolium pratense, and Plantago lanceolata) belonging to three dominant plant functional groups (grasses, legumes, and herbs). Generally, L. perenne benefited from being released from intraspecific competition in the presence of T. pratense and P. lanceolata. However, the presence of AMF increased the competitive strength of P. lanceolata and T. pratense against L. perenne and also modified the effects of Collembola on plant productivity. The colonization of roots by AMF was reduced in treatments with two plant species suggesting that plant infection by AMF was modified by interspecific plant interactions. Collembola did not affect total colonization of roots by AMF, but increased the number of mycorrhizal vesicles in P. lanceolata. AMF and Collembola both enhanced the amount of N and P in plant shoot tissue, but impacts of Collembola were less pronounced in the presence of AMF. Overall, the results suggest that, by differentially affecting the nutrient acquisition and performance of plant species, AMF and Collembola interactively modify plant competition and shape the composition of grassland plant communities. The results suggest that mechanisms shaping plant community composition can only be understood when complex belowground interactions are considered. PMID:22678109

Sabais, Alexander C W; Eisenhauer, Nico; König, Stephan; Renker, Carsten; Buscot, François; Scheu, Stefan

2012-12-01

136

Effects of Salinity on the Response of the Wetland Halophyte Kosteletzkya virginica (L.) Presl. to Copper Toxicity  

Microsoft Academic Search

Kosteletzkya virginica (L.) Presl. is a perennial wetland halophyte which could be exposed to heavy metals in polluted salt marsh environments.\\u000a In order to investigate the interaction between salinity (50 mM NaCl) and heavy metal, young plants were exposed in hydroponic\\u000a culture to 10 ?M Cu in the presence or absence of 50 mM NaCl. Copper strongly inhibited the leaf emergence and lateral

Rui-Ming Han; Isabelle Lefèvre; Cheng-Jiang Ruan; Natacha Beukelaers; Pei Qin; Stanley Lutts

137

Nurse plant effects on plant species richness in drylands: the role of grazing, rainfall and species specificity  

PubMed Central

The outcome of plant-plant interactions depends on environmental (e.g. grazing, climatic conditions) and species-specific attributes (e.g. life strategy and dispersal mode of the species involved). However, the joint effects of such factors on pairwise plant-plant interactions, and how they modulate the role of these interactions at the community level, have not been addressed before. We assessed how these species-specific (life strategy and dispersal) and environmental (grazing and rainfall) factors affected the co-occurrence of 681 plant species pairs on open woodlands in south-eastern Australia. Species-specific attributes affected the co-occurrence of most species pairs, with higher co-occurrence levels dominating for drought-intolerant species. The dispersal mechanism only affected drought-tolerant beneficiaries, with more positive co-occurrences for vertebrate-dispersed species. Conversely, the percentage of facilitated species at the community scale declined under higher rainfall availabilities. A significant grazing × rainfall interaction on the percentage of facilitated species suggests that grazing-mediated protection was important under low to moderate, but not high, rainfall availabilities. This study improves our ability to predict changes in plant-plant interactions along environmental gradients, and their effect on community species richness, by highlighting that: 1) species-specific factors were more important than environmental conditions as drivers of a large amount (~30%) of the pairwise co-occurrences evaluated; 2) grazing and rainfall interaction drive the co-occurrence among different species in the studied communities, and 3) the effect of nurse plants on plant species richness will depend on the relative dominance of particular dispersal mechanisms or life strategies prone to be facilitated.

Soliveres, Santiago; Eldridge, David J.; Hemmings, Frank; Maestre, Fernando T.

2015-01-01

138

Technical Note: Seeding Conditions of the Halophyte Atriplex Patula for Optimal Growth on a Salt Impacted Site  

Microsoft Academic Search

Salt-impacted soils resulting from oilfield brine spills are increasingly becoming a significant problem in oil-producing areas of Canada such as Alberta and Saskatchewan.The native halophyte Atriplex patula is being considered a potential species for phytoremediation of brine-impacted sites in these hemiboreal climactic zones. The objective of this study was to investigate the optimal seeding conditions under field conditions (with no

Michelle A. Young; Doug G. Rancier; Julie L. Roy; Stuart R. Lunn; Sarah A. Armstrong; John V. Headley

2011-01-01

139

Host plant species affects virulence in monarch butterfly parasites.  

PubMed

1. Studies have considered how intrinsic host and parasite properties determine parasite virulence, but have largely ignored the role of extrinsic ecological factors in its expression. 2. We studied how parasite genotype and host plant species interact to determine virulence of the protozoan parasite Ophryocystis elektroscirrha (McLaughlin & Myers 1970) in the monarch butterfly Danaus plexippus L. We infected monarch larvae with one of four parasite genotypes and reared them on two milkweed species that differed in their levels of cardenolides: toxic chemicals involved in predator defence. 3. Parasite infection, replication and virulence were affected strongly by host plant species. While uninfected monarchs lived equally long on both plant species, infected monarchs suffered a greater reduction in their life spans (55% vs. 30%) on the low-cardenolide vs. the high-cardenolide host plant. These life span differences resulted from different levels of parasite replication in monarchs reared on the two plant species. 4. The virulence rank order of parasite genotypes was unaffected by host plant species, suggesting that host plant species affected parasite genotypes similarly, rather than through complex plant species-parasite genotype interactions. 5. Our results demonstrate that host ecology importantly affects parasite virulence, with implications for host-parasite dynamics in natural populations. PMID:18177332

de Roode, Jacobus C; Pedersen, Amy B; Hunter, Mark D; Altizer, Sonia

2008-01-01

140

USING REMOTE SENSING TO DETECT AND MAP INVASIVE PLANT SPECIES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Invasive exotic plant species present a serious problem to natural resource managers in the United States. This paper presents an overview on the application of aerial photography and airborne videography for detecting invasive plant species in terrestrial and aquatic environments in the United Sta...

141

Mechanisms of plant species impacts on ecosystem nitrogen cycling  

Microsoft Academic Search

Plant species are hypothesized to impact ecosystem nitrogen cycling in two distinctly different ways. First, differences in nitrogen use efficiency can lead to positive feedbacks on the rate of nitrogen cycling. Alternatively, plant species can also control the inputs and losses of nitrogen from ecosystems. Our current understanding of litter decomposition shows that most nitrogen present within litter is not

J. M. H. Knops; K. L. Bradley; D. A. Wedin

2002-01-01

142

Microbial immobilization drives nitrogen cycling differences among plant species  

E-print Network

1840 Microbial immobilization drives nitrogen cycling differences among plant species Ramesh cycling. We examined four potential mechanisms of plant species effects on nitrogen (N) cycling. We found. of Nebraska, 348 Manter Hall, Lincoln, NE 68588, USA. In many terrestrial ecosystems nitrogen (N) limits

Minnesota, University of

143

Plant species effects on soil nematode communities in experimental grasslands  

Microsoft Academic Search

We examined the effects of 12 different plant species on soil nematode abundance and community composition, and rotifer abundance, in an experimental grassland in Northern Sweden. Monocultures were grown for six or seven growing seasons before sampling. Four monocultures were grasses, four were legumes and four were non-leguminous forbs. Plant species identity had an effect on the nematode community, both

Maria Viketoft; Cecilia Palmborg; Björn Sohlenius; Kerstin Huss-Danell; Jan Bengtsson

2005-01-01

144

Disturbance, spatial turnover, and species coexistence in grassland plant communities  

E-print Network

DISTURBANCE, SPATIAL TURNOVER, AND SPECIES COEXISTENCE IN GRASSLAND PLANT COMMUNITIES By Erin J. Questad B.S., The Pennsylvania State University, 1997 Submitted to the graduate program in Ecology and Evolutionary Biology... ___________________________ ___________________________ ___________________________ ___________________________ Date defended: ______________ ii The Dissertation Committee for Erin J. Questad certifies that this is the approved version of the following dissertation: DISTURBANCE, SPATIAL TURNOVER, AND SPECIES COEXISTENCE IN GRASSLAND PLANT...

Questad, Erin

2008-08-18

145

CHALLENGES IN DEVELOPING NEW PLANTS SPECIES FOR INDUSTRIAL USES  

Technology Transfer Automated Retrieval System (TEKTRAN)

There are new markets for many new plant species in the areas of bioproducts, biofuels, and bioenergy. The species that are suitable for these markets all have unique properties in their seed oil or other plant part, making them environmentally friendly as replacements for petroleum products, and ...

146

Phylogeographic patterns of highland and lowland plant species in Japan  

Microsoft Academic Search

As a result of ecological and historical factors, plant species occurring in mountainous regions often exhibit complex phylogeographical\\u000a structure. The aim of this review is to identify the main phylogeographic patterns of plant species in the Japanese Archipelago,\\u000a based on 63 previous studies; in particular, the intention is to examine the effects of mountains on these patterns. We classified\\u000a species

Takafumi Ohsawa; Yuji Ide

2011-01-01

147

Plant species loss decreases arthropod diversity and shifts trophic structure  

E-print Network

LETTER Plant species loss decreases arthropod diversity and shifts trophic structure Nick M. Haddad 94720 3140, USA *Correspondence: E-mail: nick_haddad@ncsu.edu Abstract Plant diversity is predicted plant and animal diversity is explained by a variety of competing hypotheses, with mixed empirical

Haddad, Nick

148

EVOLUTIONARY CHANGE IN THREE SPECIES OF COMMON ROADSIDE PLANTS  

Microsoft Academic Search

Roadsides are an interesting and unusual habitat. Plants inhabiting these degraded areas are exposed to many easily identifiable and unnatural selection pressures. In this thesis, I examine the evolutionary ecology of three species (Dipsacus sylvestris, Hesperis matronalis and Asclepias syriaca) of common roadside plants. I collected seeds from several maternal plants from three oldfield and three roadside populations. In all

LAURA LOUISE BEATON

2004-01-01

149

Evolutionary change in three species of common roadside plants  

Microsoft Academic Search

Roadsides are an interesting and unusual habitat. Plants inhabiting these degraded areas are exposed to many easily identifiable and unnatural selection pressures. In this thesis, I examine the evolutionary ecology of three species (Dipsacus sylvestris, Hesperis matronalis and Asclepias syriaca) of common roadside plants. I collected seeds from several maternal plants from three oldfield and three roadside populations. In all

Laura Louise Beaton

2004-01-01

150

Altitudinal distribution of alien plant species in the Swiss Alps  

Microsoft Academic Search

In summer 2003 we recorded the presence and abundance of alien plant species at 232 sites (107 railway stations and 125 road sites) along mountain passes in the Swiss Alps. The altitudinal distribution of species was related to the current abundance of the species in Switzerland and time since introduction. A total of 155 alien taxa were recorded. Numbers of

Thomas Becker; Hansjörg Dietz; Regula Billeter; Holger Buschmann; Peter J. Edwards

2005-01-01

151

Rare and Endangered Species of Plants--The Soviet Side  

Microsoft Academic Search

In late 1972, the Soviet Union embarked on a program to identify and document plant species that are threatened with extinction. Perhaps 2000 species in the Soviet Union are in need of monitoring or protective measures, while nearly 200 may be in immediate danger of extinction. Currently, the Soviet Union has an official, national list of endangered species, and each

Thomas S. Elias

1983-01-01

152

Final Report Parris Island Depot Invasive Plant Species  

E-print Network

Final Report Parris Island Depot Invasive Plant Species Control Monitoring December 2010 Submitted and Control Efforts Page 9 c. Herbicides Page 10 IV. 2010 Survey of Invasive Species Page 16 a. Survey Methods-native invasive species are difficult to eradicate and must be managed for control. Parris Island Marine Recruit

Bolding, M. Chad

153

Abstract Since pollen usually travels limited distances in wind-pollinated plant species, plants  

E-print Network

farther between plants. Studies of several wind-pollinated species have shown that most pollen studied by Knapp et al. (2001) did show a relationship between seed set and the number of pollenAbstract Since pollen usually travels limited distances in wind-pollinated plant species, plants

Waller, Donald M.

154

Do alien plant invasions really affect pollination success in native plant species?  

Microsoft Academic Search

A growing number of studies on naturally occurring plant species have shown that plant-plant interactions for pollination vary from competitive to facilitative. In reviewing the seven published studies on how alien species can affect the pollination success in natives, we found that all authors suggest competitive effects to dominate, either through reduced pollinator visitation rates or through increased heterospecific pollination

Anne-Line Bjerknes; Ørjan Totland; Stein Joar Hegland; Anders Nielsen

2007-01-01

155

Pollinator coupling can induce synchronized flowering in different plant species.  

PubMed

Synchronous and intermittent plant reproduction has been identified widely in diverse biomes. While synchronous flowering is normally observed within the same species, different species also flower in synchrony. A well-known example of interspecific synchrony is "general flowering" in tropical rain forests of Southeast Asia. Environmental factors, such as low temperature and drought, have been considered as major trigger of general flowering. However, environmental cues are not enough to explain general flowering because some trees do not flower even when they encounter favorable environmental cues. We propose alternative explanation of general flowering; "pollinator coupling". When species flower synchronously, the elevated pollen and nectar resource may attract increased numbers of generalist pollinators, with a concomitant enhancement of pollination success (facilitation). However, under these circumstances, plants of different species may compete with one another for limited pollinator services, resulting in declines in pollination success for individual species (competition). Here, we present a model describing resource dynamics of individual trees serviced by generalist pollinators. We analyze combinations of conditions under which plants reproduce intermittently with synchronization within species, and/or (sometimes) between different species. We show that plants synchronize flowering when the number of pollinators attracted to an area increases at an accelerating rate with increasing numbers of flowers. In this case, facilitation of flowering by different species exceeds the negative influence of interspecific plant competition. We demonstrate mathematically that co-flowering of different species occurs under a much narrower range of circumstances than intraspecific co-flowering. PMID:20800600

Tachiki, Yuuya; Iwasa, Yoh; Satake, Akiko

2010-11-21

156

Genetic diversity within a dominant plant outweighs plant species diversity in structuring an arthropod community.  

PubMed

Plant biodiversity is being lost at a rapid rate. This has spurred much interest in elucidating the consequences of this loss for higher trophic levels. Experimental tests have shown that both plant species diversity and genetic diversity within a plant species can influence arthropod community structure. However, the majority of these studies have been conducted in separate systems, so their relative importance is currently unresolved. Furthermore, potential interactions between the two levels of diversity, which likely occur in natural systems, have not been investigated. To clarify these issues, we conducted three experiments in a freshwater sand dune ecosystem. We (1) independently manipulated plant species diversity, (2) independently manipulated genetic diversity within the dominant plant species, Ammophila breviligulata, and (3) jointly manipulated genetic diversity within the dominant plant and species diversity. We found that genetic diversity within the dominant plant species, Ammophila breviligulata, more strongly influenced arthropod communities than plant species diversity, but this effect was dependent on the presence of other species. In species mixtures, A. breviligulata genetic diversity altered overall arthropod community composition, and arthropod richness and abundance peaked at the highest level of genetic diversity. Positive nonadditive effects of diversity were detected, suggesting that arthropods respond to emergent properties of diverse plant communities. However, in the independent manipulations where A. breviligulata was alone, effects of genetic diversity were weaker, with only arthropod richness responding. In contrast, plant species diversity only influenced arthropods when A. breviligulata was absent, and then only influenced herbivore abundance. In addition to showing that genetic diversity within a dominant plant species can have large effects on arthropod community composition, these results suggest that understanding how species diversity and genetic diversity interact to influence community structure may be critically important for predicting the consequences of biodiversity loss. PMID:23858643

Crawford, Kerri M; Rudgers, Jennifer A

2013-05-01

157

Evaluating plant invasions from both habitat and species perspectives  

USGS Publications Warehouse

We present an approach to quantitatively assess nonnative plant invasions at landscape scales from both habitat and species perspectives. Our case study included 34 nonnative species found in 142 plots (0.1 ha) in 14 vegetation types within the Grand Staircase-Escalante National Monument, Utah. A plot invasion index, based on nonnative species richness and cover, showed that only 16 of 142 plots were heavily invaded. A species invasive index, based on frequency, cover, and number of vegetation types invaded, showed that only 7 of 34 plant species were highly invasive. Multiple regressions using habitat characteristics (moisture index, elevation, soil P, native species richness, maximum crust development class, bare ground, and rock) explained 60% of variation in nonnative species richness and 46% of variation in nonnative species cover. Three mesic habitats (aspen, wet meadow, and perennial riparian types) were particularly invaded (31 of 34 nonnative species studied were found in these types). Species-specific logistic regression models for the 7 most invasive species correctly predicted occurrence 89% of the time on average (from 80% for Bromus tectorum, a habitat generalist, to 93% for Tamarix spp., a habitat specialist). Even with such a modest sampling intensity (<0.1% of the landscape), this multiscale sampling scheme was effective at evaluating habitat vulnerability to invasion and the occurrence of the 7 most invasive nonnative species. This approach could be applied in other natural areas to develop strategies to document invasive species and invaded habitats.

Chong, G.W.; Otsuki, Y.; Stohlgren, T.J.; Guenther, D.; Evangelista, P.; Villa, C.; Waters, A.

2006-01-01

158

Human population, grasshopper and plant species richness in European countries  

NASA Astrophysics Data System (ADS)

Surprisingly, several studies over large scales have reported a positive spatial correlation of people and biodiversity. This pattern has important implications for conservation and has been documented for well studied taxa such as plants, amphibians, reptiles, birds and mammals. However, it is unknown whether the pattern applies also to invertebrates other than butterflies and more work is needed to establish whether the species-people relationship is explained by both variables correlating with other environmental factors. We studied whether grasshopper species richness (Orthoptera, suborder Caelifera) is related to human population size in European countries. As expected, the number of Caelifera species increases significantly with increasing human population size. But this is not the case when controlling for country area, latitude and number of plant species. Variations in Caelifera species richness are primarily associated with variations in plant species richness. Caelifera species richness also increases with decreasing mean annual precipitation, Gross Domestic Product per capita (used as an indicator for economic development) and net fertility rate of the human population. Our analysis confirms the hypothesis that the broad-scale human population-biodiversity correlations can be explained by concurrent variations in factors other than human population size such as plant species richness, environmental productivity, or habitat heterogeneity. Nonetheless, more populated countries in Europe still have more Caelifera species than less populated countries and this poses a particular challenge for conservation.

Steck, Claude E.; Pautasso, Marco

2008-11-01

159

Widespread plant species: Natives versus aliens in our changing world  

USGS Publications Warehouse

Estimates of the level of invasion for a region are traditionally based on relative numbers of native and alien species. However, alien species differ dramatically in the size of their invasive ranges. Here we present the first study to quantify the level of invasion for several regions of the world in terms of the most widely distributed plant species (natives vs. aliens). Aliens accounted for 51.3% of the 120 most widely distributed plant species in North America, 43.3% in New South Wales (Australia), 34.2% in Chile, 29.7% in Argentina, and 22.5% in the Republic of South Africa. However, Europe had only 1% of alien species among the most widespread species of the flora. Across regions, alien species relative to native species were either as well-distributed (10 comparisons) or more widely distributed (5 comparisons). These striking patterns highlight the profound contribution that widespread invasive alien plants make to floristic dominance patterns across different regions. Many of the most widespread species are alien plants, and, in particular, Europe and Asia appear as major contributors to the homogenization of the floras in the Americas. We recommend that spatial extent of invasion should be explicitly incorporated in assessments of invasibility, globalization, and risk assessments. ?? 2011 Springer Science+Business Media B.V.

Stohlgren, T.J.; Pysek, P.; Kartesz, J.; Nishino, M.; Pauchard, A.; Winter, M.; Pino, J.; Richardson, D.M.; Wilson, J.R.U.; Murray, B.R.; Phillips, M.L.; Ming-yang, L.; Celesti-Grapow, L.; Font, X.

2011-01-01

160

Widespread plant species: natives vs. aliens in our changing world  

USGS Publications Warehouse

Estimates of the level of invasion for a region are traditionally based on relative numbers of native and alien species. However, alien species differ dramatically in the size of their invasive ranges. Here we present the first study to quantify the level of invasion for several regions of the world in terms of the most widely distributed plant species (natives vs. aliens). Aliens accounted for 51.3% of the 120 most widely distributed plant species in North America, 43.3% in New South Wales (Australia), 34.2% in Chile, 29.7% in Argentina, and 22.5% in the Republic of South Africa. However, Europe had only 1% of alien species among the most widespread species of the flora. Across regions, alien species relative to native species were either as well-distributed (10 comparisons) or more widely distributed (5 comparisons). These striking patterns highlight the profound contribution that widespread invasive alien plants make to floristic dominance patterns across different regions. Many of the most widespread species are alien plants, and, in particular, Europe and Asia appear as major contributors to the homogenization of the floras in the Americas. We recommend that spatial extent of invasion should be explicitly incorporated in assessments of invasibility, globalization, and risk assessments.

Stohlgren, Thomas J.; Pyšek, Petr; Kartesz, John; Nishino, Misako; Pauchard, Aníbal; Winter, Marten; Pino, Joan; Richardson, David M.; Wilson, John R.U.; Murray, Brad R.; Phillips, Megan L.; Ming-yang, Li; Celesti-Grapow, Laura; Font, Xavier

2011-01-01

161

High apoplastic solute concentrations in leaves alter water relations of the halophytic shrub, Sarcobatus vermiculatus.  

PubMed

Predawn plant water potential (Psi(w)) is used to estimate soil moisture available to plants because plants are expected to equilibrate with the root-zone Psi(w). Although this equilibrium assumption provides the basis for interpreting many physiological and ecological parameters, much work suggests predawn plant Psi(w) is often more negative than root-zone soil Psi(w). For many halophytes even when soils are well-watered and night-time shoot and root water loss eliminated, predawn disequilibrium (PDD) between leaf and soil Psi(w) can exceed 0.5 MPa. A model halophyte, Sarcobatus vermiculatus, was used to test the predictions that low predawn solute potential (Psi(s)) in the leaf apoplast is a major mechanism driving PDD and that low Psi(s) is due to high Na+ and K+ concentrations in the leaf apoplast. Measurements of leaf cell turgor (Psi(p)) and solute potential (Psi(s)) of plants grown under a range of soil salinities demonstrated that predawn symplast Psi(w) was 1.7 to 2.1 MPa more negative than predawn xylem Psi(w), indicating a significant negative apoplastic Psi(s). Measurements on isolated apoplastic fluid indicated that Na+ concentrations in the leaf apoplast ranged from 80 to 230 mM, depending on salinity, while apoplastic K+ remained around 50 mM. The water relations measurements suggest that without a low apoplastic Psi(s), predawn Psi(p) may reach pressures that could cause cell damage. It is proposed that low predawn apoplastic Psi(s) may be an efficient way to regulate Psi(p) in plants that accumulate high concentrations of osmotica or when plants are subject to fluctuating patterns of soil water availability. PMID:16317037

James, J J; Alder, N N; Mühling, K H; Läuchli, A E; Shackel, K A; Donovan, L A; Richards, J H

2006-01-01

162

Phytotoxins produced by plant pathogenic Streptomyces species.  

PubMed

Streptomyces is a large genus consisting of soil-dwelling, filamentous bacteria that are best known for their capability of producing a vast array of medically and agriculturally useful secondary metabolites. In addition, a small number of Streptomyces spp. are capable of colonizing and infecting the underground portions of living plants and causing economically important crop diseases such as potato common scab (CS). Research into the mechanisms of Streptomyces plant pathogenicity has led to the identification and characterization of several phytotoxic secondary metabolites that are known or suspected of contributing to diseases in various plants. The best characterized are the thaxtomin phytotoxins, which play a critical role in the development of CS, acid scab and soil rot of sweet potato. In addition, the best-characterized CS-causing pathogen, S. scabies, produces a molecule that is predicted to resemble the Pseudomonas syringae coronatine phytotoxin and which contributes to seedling disease symptom development. Other Streptomyces phytotoxic secondary metabolites that have been identified include concanamycins, FD-891 and borrelidin. Furthermore, there is evidence that additional, unknown metabolites may participate in Streptomyces plant pathogenicity. Such revelations have implications for the rational development of better management procedures for controlling CS and other Streptomyces plant diseases. This article is protected by copyright. All rights reserved. PMID:24131731

Bignell, Dawn R D; Fyans, Joanna K; Cheng, Zhenlong

2013-10-17

163

45 CFR 670.25 - Designation of specially protected species of native mammals, birds, and plants.  

Code of Federal Regulations, 2010 CFR

...specially protected species of native mammals, birds, and plants. 670.25 Section 670...Specially Protected Species of Mammals, Birds, and Plants § 670.25 Designation...specially protected species of native mammals, birds, and plants. The following...

2010-10-01

164

45 CFR 670.25 - Designation of specially protected species of native mammals, birds, and plants.  

Code of Federal Regulations, 2011 CFR

...specially protected species of native mammals, birds, and plants. 670.25 Section 670...Specially Protected Species of Mammals, Birds, and Plants § 670.25 Designation...specially protected species of native mammals, birds, and plants. The following...

2011-10-01

165

45 CFR 670.25 - Designation of specially protected species of native mammals, birds, and plants.  

Code of Federal Regulations, 2012 CFR

...specially protected species of native mammals, birds, and plants. 670.25 Section 670...Specially Protected Species of Mammals, Birds, and Plants § 670.25 Designation...specially protected species of native mammals, birds, and plants. The following...

2012-10-01

166

45 CFR 670.25 - Designation of specially protected species of native mammals, birds, and plants.  

Code of Federal Regulations, 2013 CFR

...specially protected species of native mammals, birds, and plants. 670.25 Section 670...Specially Protected Species of Mammals, Birds, and Plants § 670.25 Designation...specially protected species of native mammals, birds, and plants. The following...

2013-10-01

167

45 CFR 670.25 - Designation of specially protected species of native mammals, birds, and plants.  

Code of Federal Regulations, 2014 CFR

...specially protected species of native mammals, birds, and plants. 670.25 Section 670...Specially Protected Species of Mammals, Birds, and Plants § 670.25 Designation...specially protected species of native mammals, birds, and plants. The following...

2014-10-01

168

The Relation Between Unpalatable Species, Nutrients and Plant Species Richness in Swiss Montane Pastures  

Microsoft Academic Search

In agriculturally marginal areas, the control of unpalatable weeds on species rich pastures may become problematic due to\\u000a agricultural and socio-economic developments. It is unclear how increased dominance of unpalatable species would affect the\\u000a botanical diversity of these grasslands. We investigated whether there was any relationship between plant species diversity\\u000a and the abundance of unpalatable species and whether soil conditions

David Kleijn; Heinz Müller-Schärer

2006-01-01

169

Induced responses in three alkaloid-containing plant species  

Microsoft Academic Search

In this paper we test three plant species for the inducibility of their alkaloid production. The plants were heavily damaged by cutting off 50% of their leaf surface using a pair of scissors. The cut-off leaf tips were used as controls for possible diurnal fluctuations. After 3, 6, 12, 24 and 48 h, respectively, the leaf bases of the damaged

Nicole M. van Dam; Ed van der Meijden; Robert Verpoorte

1993-01-01

170

When Are Native Species Inappropriate for Conservation Plantings  

EPA Science Inventory

Conservation agencies and organizations are generally reluctant to encourage the use of invasive plant species in conservation programs. Harsh lessons learned in the past have resulted in tougher screening protocols for non-indigenous species introductions and removal of many no...

171

Origin of Floral Isolation Between Ornithophilous and Sphingophilous Plant Species  

Microsoft Academic Search

Three plant groups in temperate western North America contain closely related ornithophilous and sphingophilous species: the Aquilegia formosa\\/Aquilegia caerulea group (Ranunculaceae), the Ipomopsis aggregata group (Polemoniaceae), and the Diplacus longiflorus group (Scrophulariaceae). The ornithophilous and sphingophilous species are products of allopatric speciation on the diploid level. Geographical races which are adapted to one class of pollinators in one area where

Verne Grant

1993-01-01

172

Plant species differences in particulate matter accumulation on leaf surfaces.  

PubMed

Particulate matter (PM) accumulation on leaves of 22 trees and 25 shrubs was examined in test fields in Norway and Poland. Leaf PM in different particle size fractions (PM(10), PM(2.5), PM(0.2)) differed among the species, by 10- to 15-folds at both test sites. Pinus mugo and Pinus sylvestris, Taxus media and Taxus baccata, Stephanandra incisa and Betula pendula were efficient species in capturing PM. Less efficient species were Acer platanoides, Prunus avium and Tilia cordata. Differences among species within the same genus were also observed. Important traits for PM accumulation were leaf properties such as hair and wax cover. The ranking presented in terms of capturing PM can be used to select species for air pollution removal in urban areas. Efficient plant species and planting designs that can shield vulnerable areas in urban settings from polluting traffic etc. can be used to decrease human exposure to anthropogenic pollutants. PMID:22554531

Sæbø, A; Popek, R; Nawrot, B; Hanslin, H M; Gawronska, H; Gawronski, S W

2012-06-15

173

Trichoderma species — opportunistic, avirulent plant symbionts  

Microsoft Academic Search

Trichoderma spp. are free-living fungi that are common in soil and root ecosystems. Recent discoveries show that they are opportunistic, avirulent plant symbionts, as well as being parasites of other fungi. At least some strains establish robust and long-lasting colonizations of root surfaces and penetrate into the epidermis and a few cells below this level. They produce or release a

Charles R. Howell; Ada Viterbo; Ilan Chet; Matteo Lorito; Gary E. Harman

2004-01-01

174

Widespread plant species: natives versus aliens in our changing world  

Microsoft Academic Search

Estimates of the level of invasion for a region are traditionally based on relative numbers of native and alien species. However,\\u000a alien species differ dramatically in the size of their invasive ranges. Here we present the first study to quantify the level\\u000a of invasion for several regions of the world in terms of the most widely distributed plant species (natives

Thomas J. Stohlgren; Petr Pyšek; John Kartesz; Misako Nishino; Aníbal Pauchard; Marten Winter; Joan Pino; David M. Richardson; John R. U. Wilson; Brad R. Murray; Megan L. Phillips; Li Ming-yang; Laura Celesti-Grapow

175

Generalized plant defense: effects on multiple species  

Microsoft Academic Search

Two species of lepidopteran herbivores, Manduca sexta (Sphingidae) and Trichoplusia ni (Noctuidae), were reared on synthetic diet containing either the alkaloid nicotine or the flavonoid rutin. Survival and pupal weight of the specialist M. sexta did not differ when larvae were reared on diet containing nicotine or rutin. In contrast, the generalist T. ni did not survive on diet containing

Vera A. Krischik; Robert W. Goth; Pedro Barbosa

1991-01-01

176

Inferring plant ecosystem organization from species occurrences  

Microsoft Academic Search

In this paper, we present an approach capable of extracting insights on ecosystem organization from merely occurrence (presence\\/absence) data. We extrapolate to the collective behavior by encapsulating some simplifying assumptions within a given set of constraints, and then examine their ecological implications. We show that by using the mean occurrence and co-occurrence of species as constraints, one is able to

S. Azaele; R. Muneepeerakul; A. Rinaldo; I. Rodriguez-Iturbe

2010-01-01

177

Halophyte die-off in response to anthropogenic impacts on tidal flats  

NASA Astrophysics Data System (ADS)

This study analyzed an abrupt change in halophyte populations, especially the annual plant Suaeda japonica. The boundaries and distributions of S. japonica and Phragmites australis were determined based on the decision tree classifier of TerraSAR-X, SAVI of Landsat ETM+, and density slicing of aerial photography. A large patch of S. japonica in the eastern parts of Donggum-do, South Korea, disappeared in 2007, while populations have been stable in the western parts of the island. To understand the reason behind the sudden die-off, mean sea level was analyzed based on gaged tidal data. Sedimentation rate was measured using Vernier caliper and RTK leveling data. Sedimentation rate between 2006 and 2007 was above the threshold at which S. japonica can germinate. After the loss of an 11-ha S. japonica patch from the eastern part of Donggum-do, sedimentation was accelerated because of a decrease in tidal current caused by a series of land reclamation projects. The increased monthly exposure duration due to continuous sediment accretion altered the type of salt marsh. Our results imply that accumulated effects from a series of coastal construction projects around Ganghwa-do can change not only tide and current hydrodynamics, but also sedimentation and erosion rates, which can cause large halophyte patches to disappear.

Lee, Yoon-Kyung; Park, Wook; Choi, Jong-Kuk; Ryu, Joo-Hyung; Won, Joong-Sun

2014-12-01

178

Ragworm fatty acid profiles reveals habitat and trophic interactions with halophytes and with mercury.  

PubMed

The present study aimed to assess if ragworm fatty acids (FA) profiles could be used to discriminate their spatial distribution in an historically mercury-contaminated estuarine environment, i.e., if it was possible to differentiate ragworms present in salt marsh sediments surrounding plant roots and rhizomes (rhizosediment) from adjacent unvegetated sediment. Additionally, we also tried to determine if ragworms differed in mercury content and if these values could also be used to identify the habitat they occur in. Results show that, within the same area, ragworms can be distinguished using FA profiles and that in halophyte rhizosediment ragworms display more than twice the levels of alpha-linolenic acid (18:3n-3). The ratio cis-vaccenic/oleic acids (18:1n-7/18:ln-9) in ragworms suggests higher carnivory in unvegetated sediments. Our study indicates that ragworm FA profiles can be used to identify their habitat, their trophic interaction with halophytes and reveal a spatially contrasting feeding behaviour, which also reflects mercury accumulation. PMID:22944176

Lillebø, Ana Isabel; Cleary, Daniel Francis Richard; Marques, Bruna; Reis, Alberto; Lopes da Silva, Teresa; Calado, Ricardo

2012-11-01

179

Preferential uptake of soil nitrogen forms by grassland plant species.  

PubMed

In this study, we assessed whether a range of temperate grassland species showed preferential uptake for different chemical forms of N, including inorganic N and a range of amino acids that commonly occur in temperate grassland soil. Preferential uptake of dual-labelled (13C and 15N) glycine, serine, arginine and phenylalanine, as compared to inorganic N, was tested using plants growing in pots with natural field soil. We selected five grass species representing a gradient from fertilised, productive pastures to extensive, low productivity pastures (Lolium perenne, Holcus lanatus, Anthoxanthum odoratum, Deschampsia flexuosa, and Nardus stricta). Our data show that all grass species were able to take up directly a diversity of soil amino acids of varying complexity. Moreover, we present evidence of marked inter-species differences in preferential use of chemical forms of N of varying complexity. L. perenne was relatively more effective at using inorganic N and glycine compared to the most complex amino acid phenylalanine, whereas N. stricta showed a significant preference for serine over inorganic N. Total plant N acquisition, measured as root and shoot concentration of labelled compounds, also revealed pronounced inter-species differences which were related to plant growth rate: plants with higher biomass production were found to take up more inorganic N. Our findings indicate that species-specific differences in direct uptake of different N forms combined with total N acquisition could explain changes in competitive dominance of grass species in grasslands of differing fertility. PMID:15549402

Weigelt, Alexandra; Bol, Roland; Bardgett, Richard D

2005-02-01

180

Predicting species' maximum dispersal distances from simple plant traits.  

PubMed

Many studies have shown plant species' dispersal distances to be strongly related to life-history traits, but how well different traits can predict dispersal distances is not yet known. We used cross-validation techniques and a global data set (576 plant species) to measure the predictive power of simple plant traits to estimate species' maximum dispersal distances. Including dispersal syndrome (wind, animal, ant, ballistic, and no special syndrome), growth form (tree, shrub, herb), seed mass, seed release height, and terminal velocity in different combinations as explanatory variables we constructed models to explain variation in measured maximum dispersal distances and evaluated their power to predict maximum dispersal distances. Predictions are more accurate, but also limited to a particular set of species, if data on more specific traits, such as terminal velocity, are available. The best model (R2 = 0.60) included dispersal syndrome, growth form, and terminal velocity as fixed effects. Reasonable predictions of maximum dispersal distance (R2 = 0.53) are also possible when using only the simplest and most commonly measured traits; dispersal syndrome and growth form together with species taxonomy data. We provide a function (dispeRsal) to be run in the software package R. This enables researchers to estimate maximum dispersal distances with confidence intervals for plant species using measured traits as predictors. Easily obtainable trait data, such as dispersal syndrome (inferred from seed morphology) and growth form, enable predictions to be made for a large number of species. PMID:24669743

Tamme, Riin; Götzenberger, Lars; Zobel, Martin; Bullock, James M; Hooftman, Danny A P; Kaasik, Ants; Pärtel, Meelis

2014-02-01

181

Organic pesticide modification of species interactions in annual plant communities.  

PubMed

A method is proposed and tested for assessing multispecies responses to three pesticides (atrazine, 2,4-D and malathion). Pesticides were applied at two concentrations, on model plant communities grown in raised beds using soil containing a natural seed bank. Cover by species was monitored over time in nested 10 and 20 cm diameter neighbourhoods around Poa annua and Calandrinia ciliata target plants. All tested compounds modified relative species abundance, altered dominance and simplified the treated communities. Community biomass decreased with atrazine and 2,4-D treatments, but not with malathion. Each chemical altered species interactions for all treated communities, including the identities of interacting species and the timing of interactions. Each target species had its own suite of interacting species that individually changed with chemical treatment. When cover was used as a predictor of neighbour influence, analysis of species interactions using 10 cm neighbourhoods indicated more interactions than using 20 cm neighbourhoods. When biomass was used as the predictor, use of the 20 cm neighbourhoods indicated more interactions. This method of using model plant communities for field toxicity testing is simple, economical and effective. It uses naturally occurring plants while reducing the environmental heterogeneity common in most field studies. PMID:24197547

Pfleeger, T; Zobel, D

1995-02-01

182

Sagina maritima Don (Caryophyllaceae) and other halophytes in London  

Microsoft Academic Search

Sagina maritima has been recorded at three sites by the River Thames near central London, much further from the open sea than elsewhere in Britain. Other halophytes occur nearby. Hydrological data and other records suggest that saline water carrying seeds or other propagules penetrated far upstream during periods of unusually low freshwater river flow. These are the first records of

J. A. EDGINGTON

183

Towards a working list of all known plant species.  

PubMed Central

A complete listing of the world's known plant species has long been considered desirable but has remained an elusive target for generations of botanists. The adoption of the Global Strategy for Plant Conservation has reinforced the urgent need for a global plant checklist to support, facilitate and monitor the conservation and sustainable use of plant diversity worldwide. The increasing availability of large databases of biological information over the Internet has demonstrated that many of the obstacles to the collation and dissemination of vast, shared datasets can be overcome. We examine the challenges that still remain to be addressed if the botanical community is to achieve its ambitious objective of delivering a working list of all known plant species by 2010. PMID:15253353

Lughadha, Eimear Nic

2004-01-01

184

Deficit irrigation of a landscape halophyte for reuse of saline waste water in a desert city  

USGS Publications Warehouse

Saline waste waters from industrial and water treatment processes are an under-utilized resource in desert urban environments. Management practices to safely use these water sources are still in development. We used a deeprooted native halophyte, Atriplex lentiformis (quailbush), to absorb mildly saline effluent (1800 mg l-1 total dissolved solids, mainly sodium sulfate) from a water treatment plant in the desert community of Twentynine Palms, California. We developed a deficit irrigation strategy to avoid discharging water past the root zone to the aquifer. The plants were irrigated at about one-third the rate of reference evapotranspiration (ETo) calculated from meteorological data over five years and soil moisture levels were monitored to a soil depth of 4.7 m at monthly intervals with a neutron hydroprobe. The deficit irrigation schedule maintained the soil below field capacity throughout the study. Water was presented on a more or less constant schedule, so that the application rates were less than ETo in summer and equal to or slightly greater than ETo in winter, but the plants were able to consume water stored in the profile in winter to support summer ET. Sodium salts gradually increased in the soil profile over the study but sulfate levels remained low, due to formation of gypsum in the calcic soil. The high salt tolerance, deep roots, and drought tolerance of desert halophytes such as A. lentiformis lend these plants to use as deficit-irrigated landscape plants for disposal of effluents in urban setting when protection of the aquifer is important. ?? 2008 Elsevier B.V.

Glenn, E.P.; Mckeon, C.; Gerhart, V.; Nagler, P.L.; Jordan, F.; Artiola, J.

2009-01-01

185

Species differences in whole plant carbon balance following winter dormancy in Alaskan tundra plants  

Microsoft Academic Search

We froze ramets of seven vascular plant species and a mixed community of mosses common to upland tussock tundra for several months, then measured whole-plant photosynthesis and respiration in a growth chamber under simulated spring conditions, to examine whole plant carbon metabolism following winter dormancy. In addition, respiration and photosynthesis of aboveground stems and leaves were measured in the field

M. S. Bret-Harte; F. S. Chapin

1995-01-01

186

Herbivore effects on plant species density at varying productivity levels  

USGS Publications Warehouse

Artificially increasing primary productivity decreases plant species richness in many habitats; herbivory may affect this outcome, but it has rarely been directly addressed in fertilization studies. This experiment was conducted in two Louisiana coastal marshes to examine the effects of nutrient enrichment and sediment addition on herbaceous plant communities with and without vertebrate herbivory. After three growing seasons, fertilization increased community biomass in all plots, but decreased species density (the number of species per unit area) only in plots protected from herbivory. Herbivory alone did not alter species density at either site. At the brackish marsh, herbivory caused a shift in dominance in the fertilized plots from a species that is considered the competitive dominant, but is selectively eaten, to another less palatable species. At the fresh marsh, increased dead biomass in the absence of herbivory and in the fertilized plots probably contributed to the decrease in species density, perhaps by limiting germination of annuals. Our results support those of other fertilization studies in which plant species density decreases with increased biomass, but only in those plots protected from herbivory.

Gough, L.; Grace, J.B.

1998-01-01

187

No universal scale-dependent impacts of invasive species on native plant species richness  

PubMed Central

A growing number of studies seeking generalizations about the impact of plant invasions compare heavily invaded sites to uninvaded sites. But does this approach warrant any generalizations? Using two large datasets from forests, grasslands and desert ecosystems across the conterminous United States, we show that (i) a continuum of invasion impacts exists in many biomes and (ii) many possible species–area relationships may emerge reflecting a wide range of patterns of co-occurrence of native and alien plant species. Our results contradict a smaller recent study by Powell et al. 2013 (Science 339, 316–318. (doi:10.1126/science.1226817)), who compared heavily invaded and uninvaded sites in three biomes and concluded that plant communities invaded by non-native plant species generally have lower local richness (intercepts of log species richness–log area regression lines) but steeper species accumulation with increasing area (slopes of the regression lines) than do uninvaded communities. We conclude that the impacts of plant invasions on plant species richness are not universal. PMID:24478201

Stohlgren, Thomas J.; Rejmánek, Marcel

2014-01-01

188

No universal scale-dependent impacts of invasive species on native plant species richness.  

PubMed

A growing number of studies seeking generalizations about the impact of plant invasions compare heavily invaded sites to uninvaded sites. But does this approach warrant any generalizations? Using two large datasets from forests, grasslands and desert ecosystems across the conterminous United States, we show that (i) a continuum of invasion impacts exists in many biomes and (ii) many possible species-area relationships may emerge reflecting a wide range of patterns of co-occurrence of native and alien plant species. Our results contradict a smaller recent study by Powell et al. 2013 (Science 339, 316-318. (doi:10.1126/science.1226817)), who compared heavily invaded and uninvaded sites in three biomes and concluded that plant communities invaded by non-native plant species generally have lower local richness (intercepts of log species richness-log area regression lines) but steeper species accumulation with increasing area (slopes of the regression lines) than do uninvaded communities. We conclude that the impacts of plant invasions on plant species richness are not universal. PMID:24478201

Stohlgren, Thomas J; Rejmánek, Marcel

2014-01-01

189

Resource heterogeneity, soil fertility, and species diversity: effects of clonal species on plant communities.  

PubMed

Spatial heterogeneity in soil resources is widely thought to promote plant species coexistence, and this mechanism figures prominently in resource-ratio models of competition. However, most experimental studies have found that nutrient enhancements depress diversity regardless of whether nutrients are uniformly or heterogeneously applied. This mismatch between theory and empirical pattern is potentially due to an interaction between plant size and the scale of resource heterogeneity. Clonal plants that spread vegetatively via rhizomes or stolons can grow large and may integrate across resource patches, thus reducing the positive effect of small-scale resource heterogeneity on plant species richness. Many rhizomatous clonal species respond strongly to increased soil fertility, and they have been hypothesized to drive the descending arm of the hump-shaped productivity-diversity relationship in grasslands. We tested whether clonals reduce species richness in a grassland community by manipulating nutrient heterogeneity, soil fertility, and the presence of rhizomatous clonal species in a 6-year field experiment. We found strong and consistent negative effects of clonals on species richness. These effects were greatest at high fertility and when soil resources were applied at a scale at which rhizomatous clonals could integrate across resource patches. Thus, we find support for the hypothesis that plant size and resource heterogeneity interact to determine species diversity. PMID:21508605

Eilts, J Alexander; Mittelbach, Gary G; Reynolds, Heather L; Gross, Katherine L

2011-05-01

190

Plant–soil interactions in the expansion and native range of a poleward shifting plant species  

Microsoft Academic Search

Climate warming causes range shifts of many species toward higher latitudes and altitudes. However, range shifts of host species do not necessarily proceed at the same rates as those of their enemies and symbionts. Here, we examined how a range shifting plant species performs in soil from its original range in comparison with soil from the expansion range. Tragopogon dubius

Grunsven Van R. H. A; W. H. Van der Putten; T. M. Bezemer; F. Berendse; E. M. Veenendaal

2010-01-01

191

Plant-soil interactions in the expansion and native range of a poleward shifting plant species  

Microsoft Academic Search

Climate warming causes range shifts of many species toward higher latitudes and altitudes. However, range shifts of host species do not necessarily proceed at the same rates as those of their enemies and symbionts. Here, we examined how a range shifting plant species performs in soil from its original range in comparison with soil from the expansion range. Tragopogon dubius

Grunsven van R. H. A; Putten van der W. H; T. M. Bezemer; F. Berendse; E. M. Veenendaal

2010-01-01

192

The SbASR-1 gene cloned from an extreme halophyte Salicornia brachiata enhances salt tolerance in transgenic tobacco.  

PubMed

Salinity severely affects plant growth and development. Plants evolved various mechanisms to cope up stress both at molecular and cellular levels. Halophytes have developed better mechanism to alleviate the salt stress than glycophytes, and therefore, it is advantageous to study the role of different genes from halophytes. Salicornia brachiata is an extreme halophyte, which grows luxuriantly in the salty marshes in the coastal areas. Earlier, we have isolated SbASR-1 (abscisic acid stress ripening-1) gene from S. brachiata using cDNA subtractive hybridisation library. ASR-1 genes are abscisic acid (ABA) responsive, whose expression level increases under abiotic stresses, injury, during fruit ripening and in pollen grains. The SbASR-1 transcript showed up-regulation under salt stress conditions. The SbASR-1 protein contains 202 amino acids of 21.01-kDa molecular mass and has 79 amino acid long signatures of ABA/WDS gene family. It has a maximum identity (73 %) with Solanum chilense ASR-1 protein. The SbASR-1 has a large number of disorder-promoting amino acids, which make it an intrinsically disordered protein. The SbASR-1 gene was over-expressed under CaMV 35S promoter in tobacco plant to study its physiological functions under salt stress. T(0) transgenic tobacco seeds showed better germination and seedling growth as compared to wild type (Wt) in a salt stress condition. In the leaf tissues of transgenic lines, Na(+) and proline contents were significantly lower, as compared to Wt plant, under salt treatment, suggesting that transgenic plants are better adapted to salt stress. PMID:22639284

Jha, Bhavanath; Lal, Sanjay; Tiwari, Vivekanand; Yadav, Sweta Kumari; Agarwal, Pradeep K

2012-12-01

193

Rare and endangered species of plants--the soviet side.  

PubMed

In late 1972, the Soviet Union embarked on a program to identify and document plant species that are threatened with extinction. Perhaps 2000 species in the Soviet Union are in need of monitoring or protective measures, while nearly 200 may be in immediate danger of extinction. Currently, the Soviet Union has an official, national list of endangered species, and each of the 15 republics has prepared a regional list. Once a revised national list is prepared, Soviet scientists hope that the Supreme Soviet will pass a law protecting those species. A corresponding law for endangered animals was passed in 1980. PMID:17734310

Elias, T S

1983-01-01

194

Effects of plant host species and plant community richness on streptomycete community structure.  

PubMed

We investigated soil streptomycete communities associated with four host plant species (two warm season C4 grasses: Andropogon gerardii, Schizachyrium scoparium and two legumes: Lespedeza capitata, Lupinus perennis), grown in plant communities varying in species richness. We used actinobacteria-selective PCR coupled with pyrosequencing to characterize streptomycete community composition and structure. The greatest pairwise distances between communities were observed in contrasts between monocultures of different plant species, indicating that plant species exert distinct selective effects on soil streptomycete populations. Increasing plant richness altered the composition and structure of streptomycete communities associated with each host plant species. Significant relationships between plant community characteristics, soil edaphic characteristics, and streptomycete community structure suggest that host plant effects on soil microbial communities may be mediated through changes to the soil environment. Co-occurring streptomycete taxa also shared consistent relationships with soil edaphic properties, providing further indication of the importance of habitat preference for taxon occurrence. Physical distance between sampling points had a significant influence on streptomycete community similarity. This work provides a detailed characterization of soil streptomycete populations across a field scale and in relation to plant host identity and plant community richness. PMID:23013423

Bakker, Matthew G; Bradeen, James M; Kinkel, Linda L

2013-03-01

195

Ecological effects of roads on the plant diversity of coastal wetland in the Yellow River Delta.  

PubMed

The 26 sample sites in 7 study plots adjacent to asphalt road and earth road in coastal wetland in the Yellow River Delta were selected to quantify plant diversity using quadrat sampling method in plant bloom phase of July and August 2012. The indice of ? T and Jaccard's coefficient were applied to evaluate the species diversity. The results showed that the plant diversities and alien plants were high in the range of 0-20 m to the road verge. There were more exotics and halophytes in plots of asphalt roadside than that of earth roadside. However, proportion of halophytes in habitats of asphalt roadsides was lower than that of earth roadside. By comparing ?-diversity, there were more common species in the asphalt roadsides than that in the earth roadsides. The similarity of plant communities in studied plots of asphalt roadsides and earth roadsides increased with increasing the distance to road verge. The effect range of roads for plant diversity in study region was about 20 m to road verge. Our results indicate that the construction and maintenance of roads in wetland could increase the plant species diversities of communities and risk of alien species invasion. PMID:25147872

Li, Yunzhao; Yu, Junbao; Ning, Kai; Du, Siyao; Han, Guangxuan; Qu, Fanzhu; Wang, Guangmei; Fu, Yuqin; Zhan, Chao

2014-01-01

196

Ecological Effects of Roads on the Plant Diversity of Coastal Wetland in the Yellow River Delta  

PubMed Central

The 26 sample sites in 7 study plots adjacent to asphalt road and earth road in coastal wetland in the Yellow River Delta were selected to quantify plant diversity using quadrat sampling method in plant bloom phase of July and August 2012. The indice of ?T and Jaccard's coefficient were applied to evaluate the species diversity. The results showed that the plant diversities and alien plants were high in the range of 0–20?m to the road verge. There were more exotics and halophytes in plots of asphalt roadside than that of earth roadside. However, proportion of halophytes in habitats of asphalt roadsides was lower than that of earth roadside. By comparing ?-diversity, there were more common species in the asphalt roadsides than that in the earth roadsides. The similarity of plant communities in studied plots of asphalt roadsides and earth roadsides increased with increasing the distance to road verge. The effect range of roads for plant diversity in study region was about 20?m to road verge. Our results indicate that the construction and maintenance of roads in wetland could increase the plant species diversities of communities and risk of alien species invasion. PMID:25147872

Li, Yunzhao; Du, Siyao; Han, Guangxuan; Qu, Fanzhu; Wang, Guangmei; Fu, Yuqin; Zhan, Chao

2014-01-01

197

Plant species richness regulates soil respiration through changes in productivity  

PubMed Central

Soil respiration is an important pathway of the C cycle. However, it is still poorly understood how changes in plant community diversity can affect this ecosystem process. Here we used a long-term experiment consisting of a gradient of grassland plant species richness to test for effects of diversity on soil respiration. We hypothesized that plant diversity could affect soil respiration in two ways. On the one hand, more diverse plant communities have been shown to promote plant productivity, which could increase soil respiration. On the other hand, the nutrient concentration in the biomass produced has been shown to decrease with diversity, which could counteract the production-induced increase in soil respiration. Our results clearly show that soil respiration increased with species richness. Detailed analysis revealed that this effect was not due to differences in species composition. In general, soil respiration in mixtures was higher than would be expected from the monocultures. Path analysis revealed that species richness predominantly regulates soil respiration through changes in productivity. No evidence supporting the hypothesized negative effect of lower N concentration on soil respiration was found. We conclude that shifts in productivity are the main mechanism by which changes in plant diversity may affect soil respiration. Electronic supplementary material The online version of this article (doi:10.1007/s00442-010-1569-5) contains supplementary material, which is available to authorized users. PMID:20169454

van Ruijven, Jasper; Berendse, Frank

2010-01-01

198

Floristic summary of plant species in the air pollution literature.  

PubMed

A floristic summary and analysis was performed on a list of the plant species that have been studied for the effects of gaseous and chemical air pollutants on vegetation in order to compare the species with the flora of North America north of Mexico. The scientific names of 2081 vascular plant species were extracted from almost 4000 journal articles stored in two large literature databases on the effects of air pollutants on plants. Three quarters of the plant species studied occur in North America, but this was only 7% of the total North American flora. Sixteen percent and 56% of all North American genera and families have been studied. The most studied genus is Pinus with 70% of the North American species studied, and the most studied family is the grass family, with 12% of the species studied. Although Pinus is ranked 86th in the North American flora, the grass family is ranked third, indicating that representation at the family level is better than at the genus level. All of the top ten families in North America are represented in the top 20 families in the air pollution effects literature, but only one genus (Lupinus) in the top ten genera in North America is represented in the top thirteen genera in the air pollution literature. PMID:15091376

Bennett, J P

1996-01-01

199

Floristic summary of plant species in the air pollution literature  

USGS Publications Warehouse

A floristic summary and analysis was performed on a list of the plant species that have been studied for the effects of gaseous and chemical air pollutants on vegetation in order to compare the species with the flora of North America north of Mexico. The scientific names of 2081 vascular plant species were extracted from almost 4000 journal articles stored in two large literature databases on the effects of air pollutants on plants. Three quarters of the plant species studied occur in North America, but this was only 7% of the total North American flora. Sixteen percent and 56% of all North American genera and families have been studied. The most studied genus is Pinus with 70% of the North American species studied, and the most studied family is the grass family, with 12% of the species studied. Although Pinus is ranked 86th in the North American flora, the grass family is ranked third, indicating that representation at the family level is better than at the genus level. All of the top ten families in North America are represented in the top 20 families in the air pollution effects literature, but only one genus (Lupinus) in the top ten genera in North America is represented in the top thirteen genera in the air pollution literature.

Bennett, J.P.

1996-01-01

200

Effects of thermoperiod on recovery of seed germination of halophytes from saline conditions.  

PubMed

Recovery of seed germination from NaCl salinity of desert shrubs (Haloxylon recurvum and Suaeda fruticosa, and the herbs Zygophyllum simplex and Triglochin maritima was studied under various thermoperiods. The percentage of ungerminated seeds that recovered when they were transferred to distilled water varied significantly with variation in species and thermoperiods. Zygophyllum simplex had little recovery from all NaCl concentrations in all thermoperiods. Haloxylon recurvum, S. fruticosa, and T. maritima showed substantial recovery. Percentage recovery was highest in S. fruticosa, followed by T. maritima, and H. recurvum. Thermoperiodic effects varied with the species investigated. There was little thermoperodic effect on the percentage recovery of S. fruticosa, except in the higher salinity treatment at higher thermoperiods. Variation in thermoperiod appears to play an important role in recovery of germination of halophytes from salt stress when seeds are transferred to distilled water. PMID:21712207

Khan, M; Ungar, I

1997-02-01

201

Plant DNA barcodes and species resolution in sedges (Carex, Cyperaceae).  

PubMed

We investigate the species discriminatory power of a subset of the proposed plant barcoding loci (matK, rbcL, rpoC1, rpoB, trnH-psbA) in Carex, a cosmopolitan genus that represents one of the three largest plant genera on earth (c. 2000 species). To assess the ability of barcoding loci to resolve Carex species, we focused our sampling on three of the taxonomically best-known groups in the genus, sections Deweyanae (6/8 species sampled), Griseae (18/21 species sampled), and Phyllostachyae (10/10 species sampled). Each group represents one of three major phylogenetic lineages previously identified in Carex and its tribe Cariceae, thus permitting us to evaluate the potential of DNA barcodes to broadly identify species across the tribe and to differentiate closely related sister species. Unlike some previous studies that have suggested that plant barcoding could achieve species identification rates around 90%, our results suggest that no single locus or multilocus barcode examined will resolve much greater than 60% of Carex species. In fact, no multilocus combination can significantly increase the resolution and statistical support (i.e., ? 70% bootstrap) for species than matK alone, even combinations involving the second most variable region, trnH-psbA. Results suggest that a matK barcode could help with species discovery as 47% of Carex taxa recently named or resolved within cryptic complexes in the past 25 years also formed unique species clusters in upgma trees. Comparisons between the nrDNA internal transcribed spacer region (ITS) and matK in sect. Phyllostachyae suggest that matK not only discriminates more species (50-60% vs. 25%), but it provides more resolved phylogenies than ITS. Given the low levels of species resolution in rpoC1 and rpoB (0-13%), and difficulties with polymerase chain reaction amplification and DNA sequencing in rbcL and trnH-psbA (alignment included), we strongly advocate that matK should be part of a universal plant barcoding system. Although identification rates in this study are low, they can be significantly improved by a regional approach to barcoding. PMID:21564974

Starr, Julian R; Naczi, Robert F C; Chouinard, Brianna N

2009-05-01

202

Which ornamental plant species effectively remove benzene from indoor air?  

NASA Astrophysics Data System (ADS)

Phytoremediation—using plants to remove toxins—is an attractive and cost effective way to improve indoor air quality. This study screened ornamental plants for their ability to remove volatile organic compounds from air by fumigating 73 plant species with 150 ppb benzene, an important indoor air pollutant that poses a risk to human health. The 10 species found to be most effective at removing benzene from air were fumigated for two more days (8 h per day) to quantify their benzene removal capacity. Crassula portulacea, Hydrangea macrophylla, Cymbidium Golden Elf., Ficus microcarpa var. fuyuensis, Dendranthema morifolium, Citrus medica var. sarcodactylis, Dieffenbachia amoena cv. Tropic Snow; Spathiphyllum Supreme; Nephrolepis exaltata cv. Bostoniensis; Dracaena deremensis cv. Variegata emerged as the species with the greatest capacity to remove benzene from indoor air.

Liu, Yan-Ju; Mu, Yu-Jing; Zhu, Yong-Guan; Ding, Hui; Crystal Arens, Nan

203

Genetic variation within a dominant shrub species determines plant species colonization in a coastal dune ecosystem.  

PubMed

The diversity and structure of plant communities is often determined by the presence and identity of competitively dominant species. Recent studies suggest that intraspecific variation within dominants may also have important community-level consequences. In a coastal dunes ecosystem of northern California, we use a decade-old common garden experiment to test the effects of a genetically based architectural dimorphism within a dominant native shrub, Baccharis pilularis, on plant colonization success and understory plant diversity. We found that erect Baccharis morphs had higher richness and cover of colonizing plant species (both native and exotic species) compared to prostrate morphs, as well as higher biomass of a dominant exotic dune grass (Ammophila arenaria). Trait differences between architectural morphs influenced the abiotic understory environment (light availability, soil surface temperature, and litter depth) and were associated with species colonization success. Taken together, our results demonstrate that incorporating within-species variation, particularly within dominant species, into community ecological research can increase the ability to predict patterns of species diversity and assembly within communities. PMID:20462137

Crutsinger, Gregory M; Strauss, Sharon Y; Rudgers, Jennifer A

2010-04-01

204

Aminomethylphosphonic acid accumulation in plant species treated with glyphosate.  

PubMed

Aminomethylphosphonic acid (AMPA) is the most frequently detected metabolite of glyphosate in plants. The objective of this study was to determine if there is any correlation of metabolism of glyphosate to AMPA in different plant species and their natural level of resistance to glyphosate. Greenhouse studies were conducted to determine the glyphosate I 50 values (rate required to cause a 50% reduction in plant growth) and to quantify AMPA and shikimate concentrations in selected leguminous and nonleguminous species treated with glyphosate at respective I 50 rates. Coffee senna [ Cassia occidentalis (L.) Link] was the most sensitive ( I 50 = 75 g/ha) and hemp sesbania [ Sesbania herbacea (P.Mill.) McVaugh] was the most resistant ( I 50 = 456 g/ha) to glyphosate. Hemp sesbania was 6-fold and Illinois bundleflower [ Desmanthus illinoensis (Michx.) MacM. ex B.L.Robins. & Fern.] was 4-fold more resistant to glyphosate than coffee senna. Glyphosate was present in all plant species, and its concentration ranged from 0.308 to 38.7 microg/g of tissue. AMPA was present in all leguminous species studied except hemp sesbania. AMPA concentration ranged from 0.119 to 4.77 microg/g of tissue. Shikimate was present in all plant species treated with glyphosate, and levels ranged from 0.053 to 16.5 mg/g of tissue. Non-glyphosate-resistant (non-GR) soybean accumulated much higher shikimate than glyphosate-resistant (GR) soybean. Although some leguminous species were found to be more resistant to glyphosate than others, and there was considerable variation between species in the glyphosate to AMPA levels found, metabolism of glyphosate to AMPA did not appear to be a common factor in explaining natural resistance levels. PMID:18298069

Reddy, Krishna N; Rimando, Agnes M; Duke, Stephen O; Nandula, Vijay K

2008-03-26

205

Regeneration niche differentiates functional strategies of desert woody plant species  

PubMed Central

Plant communities vary dramatically in the number and relative abundance of species that exhibit facilitative interactions, which contributes substantially to variation in community structure and dynamics. Predicting species’ responses to neighbors based on readily measurable functional traits would provide important insight into the factors that structure plant communities. We measured a suite of functional traits on seedlings of 20 species and mature plants of 54 species of shrubs from three arid biogeographic regions. We hypothesized that species with different regeneration niches—those that require nurse plants for establishment (beneficiaries) versus those that do not (colonizers)—are functionally different. Indeed, seedlings of beneficiary species had lower relative growth rates, larger seeds and final biomass, allocated biomass toward roots and height at a cost to leaf mass fraction, and constructed costly, dense leaf and root tissues relative to colonizers. Likewise at maturity, beneficiaries had larger overall size and denser leaves coupled with greater water use efficiency than colonizers. In contrast to current hypotheses that suggest beneficiaries are less “stress-tolerant” than colonizers, beneficiaries exhibited conservative functional strategies suited to persistently dry, low light conditions beneath canopies, whereas colonizers exhibited opportunistic strategies that may be advantageous in fluctuating, open microenvironments. In addition, the signature of the regeneration niche at maturity indicates that facilitation expands the range of functional diversity within plant communities at all ontogenetic stages. This study demonstrates the utility of specific functional traits for predicting species’ regeneration niches in hot deserts, and provides a framework for studying facilitation in other severe environments. Electronic supplementary material The online version of this article (doi:10.1007/s00442-010-1741-y) contains supplementary material, which is available to authorized users. PMID:20686787

Briggs, John M.

2010-01-01

206

Non-indigenous aquatic and semiaquatic plant species in France  

Microsoft Academic Search

The invasion of natural communities by introduced plants constitutes one of the most serious threats to biodiversity (Heywood\\u000a 1989). What is the current situation in France? What do we know about these invasions and their consequences? What measures\\u000a have been implemented to manage non-indigenous plant species populations? To respond to these questions, the French Ministry\\u000a for Ecology and Sustainable Development

Gabrielle Thiébaut

207

Antioxidative properties of bee pollen in selected plant species  

Microsoft Academic Search

Phenolic constituents (total phenols, phenylpropanoids, flavonols and anthocyanins) and antioxidant ability were determined in bee pollen of 12 plant species. Antioxidant ability was measured as total antioxidant activity, radical-scavenging activity and activity against free hydroxyl radical. Great variability of phenolic contents was observed in the pollen of investigated species. Total antioxidant activity differed considerably (0.8–86.4% inhibition of lipid peroxidation), however,

M. Leja; A. Mareczek; G. Wy?golik; J. Klepacz-Baniak; K. Czeko?ska

2007-01-01

208

Habitat origins and microhabitat preferences of urban plant species  

Microsoft Academic Search

Urban vegetation is commonly described as dominated by weedy species that are adapted to human disturbance. In this study,\\u000a we determined the original (pre-agriculture) habitats of urban plant species sampled quantitatively in the spontaneous vegetation\\u000a of a university campus in Halifax, Nova Scotia (eastern Canada). We sampled 11 distinct patch types corresponding to different\\u000a built forms. Differences in vegetation among

J. T. Lundholm; A. Marlin

2006-01-01

209

Differential nitrogen and phosphorus retention by five wetland plant species  

Microsoft Academic Search

Riparian wetlands have a demonstrated ability to filter and control nitrogen (N) and phosphorus (P) movement into streams\\u000a and other bodies of water; few studies, however, have examined the roles that individual plant species serve in sequestering\\u000a N and P pollutants. We evaluated the potential for growth and consequent N and P accumulation by five species of wetland perennials.\\u000a We

Jenny T. Kao; John E. Titus; Wei-Xing Zhu

2003-01-01

210

Species-specific toxicity of ceria nanoparticles to Lactuca plants.  

PubMed

Species-specific differences in the toxicity of manufactured nanoparticles (MNPs) have been reported, but the underlying mechanisms are unknown. We previously found that CeO2 NPs inhibited root elongation of head lettuce, whereas no toxic effect was observed on other plants (such as wheat, cucumber and radish). In this study, interactions between Lactuca plants and three types of CeO2 NPs (lab-synthesized 7 and 25?nm CeO2 NPs, and a commercial CeO2 NPs) were investigated. It was found that CeO2 NPs were toxic to three kinds of Lactuca genus plants and different CeO2 NPs showed different degrees of toxicity. The results of X-ray absorption near edge fine structure indicate that small parts of CeO2 NPs were transformed from Ce(IV) to Ce(III) in roots of the plants that were treated with CeO2 NPs during the seed germination stage. But the high sensitivity of Lactuca plants to the released Ce(3+) ions caused the species-specific phytotoxicity of CeO2 NPs. Differences in sizes and zeta potentials among three types of CeO2 NPs resulted in their different degrees of biotransformation which accounted for the discrepancy in the toxicity to Lactuca plants. This study is among the few, and may indeed the first, that addresses the relation between the physicochemical properties of nanoparticles and its species-specific phytotoxicity. PMID:24256192

Zhang, Peng; Ma, Yuhui; Zhang, Zhiyong; He, Xiao; Li, Yuanyuan; Zhang, Jing; Zheng, Lirong; Zhao, Yuliang

2015-02-01

211

Taxonomic perspective of plant species yielding vegetable oils used in cosmetics and skin care products  

Microsoft Academic Search

A search conducted to determine the plants yielding vegetable oils resulted in 78 plant species with potential use in cosmetics and skin care products. The taxonomic position of these plant species is described with a description of vegetable oils from these plants and their use in cosmetics and skin care products. These species belonged to 74 genera and 45 plant

Mohammad Athar; Syed Mahmood Nasir

212

77 FR 61663 - Endangered and Threatened Wildlife and Plants; Determination of Endangered Species Status for the...  

Federal Register 2010, 2011, 2012, 2013, 2014

...and Plants; Determination of Endangered Species Status for the Alabama Pearlshell...and Plants; Determination of Endangered Species Status for the Alabama Pearlshell...Wildlife Service, determine endangered species status for the Alabama...

2012-10-10

213

7 CFR 650.22 - Rare, threatened, and endangered species of plants and animals.  

Code of Federal Regulations, 2014 CFR

...false Rare, threatened, and endangered species of plants and animals. 650...22 Rare, threatened, and endangered species of plants and animals. ...principal hazard to threatened and endangered species is the destruction...

2014-01-01

214

7 CFR 650.22 - Rare, threatened, and endangered species of plants and animals.  

Code of Federal Regulations, 2013 CFR

...false Rare, threatened, and endangered species of plants and animals. 650...22 Rare, threatened, and endangered species of plants and animals. ...principal hazard to threatened and endangered species is the destruction...

2013-01-01

215

78 FR 57749 - Endangered and Threatened Wildlife and Plants; Determination of Endangered Species Status for...  

Federal Register 2010, 2011, 2012, 2013, 2014

...and Plants; Determination of Endangered Species Status for Mount Charleston...and Plants; Determination of Endangered Species Status for Mount Charleston...Service (Service), determine endangered species status under the...

2013-09-19

216

7 CFR 650.22 - Rare, threatened, and endangered species of plants and animals.  

Code of Federal Regulations, 2012 CFR

...false Rare, threatened, and endangered species of plants and animals. 650...22 Rare, threatened, and endangered species of plants and animals. ...principal hazard to threatened and endangered species is the destruction...

2012-01-01

217

7 CFR 650.22 - Rare, threatened, and endangered species of plants and animals.  

Code of Federal Regulations, 2011 CFR

...false Rare, threatened, and endangered species of plants and animals. 650...22 Rare, threatened, and endangered species of plants and animals. ...principal hazard to threatened and endangered species is the destruction...

2011-01-01

218

7 CFR 650.22 - Rare, threatened, and endangered species of plants and animals.  

Code of Federal Regulations, 2010 CFR

...false Rare, threatened, and endangered species of plants and animals. 650...22 Rare, threatened, and endangered species of plants and animals. ...principal hazard to threatened and endangered species is the destruction...

2010-01-01

219

Metal species involved in long distance metal transport in plants  

PubMed Central

The mechanisms plants use to transport metals from roots to shoots are not completely understood. It has long been proposed that organic molecules participate in metal translocation within the plant. However, until recently the identity of the complexes involved in the long-distance transport of metals could only be inferred by using indirect methods, such as analyzing separately the concentrations of metals and putative ligands and then using in silico chemical speciation software to predict metal species. Molecular biology approaches also have provided a breadth of information about putative metal ligands and metal complexes occurring in plant fluids. The new advances in analytical techniques based on mass spectrometry and the increased use of synchrotron X-ray spectroscopy have allowed for the identification of some metal-ligand species in plant fluids such as the xylem and phloem saps. Also, some proteins present in plant fluids can bind metals and a few studies have explored this possibility. This study reviews the analytical challenges researchers have to face to understand long-distance metal transport in plants as well as the recent advances in the identification of the ligand and metal-ligand complexes in plant fluids. PMID:24723928

Álvarez-Fernández, Ana; Díaz-Benito, Pablo; Abadía, Anunciación; López-Millán, Ana-Flor; Abadía, Javier

2014-01-01

220

Spatial connectedness of plant species: potential links for apparent competition via plant diseases  

E-print Network

. Bouteloua curtipendula was uncommon but occurred in all environments, while Buchloe dactyloides and Bouteloua gracilis were uncommon and only occurred in upland sites. Co-occurrence of plant species

Garrett, Karen A.

221

AIRBORNE HYPERSPECTRAL IDENTIFICATION OF INVASIVE AND OPPORTUNISTIC WETLANDS PLANT SPECIES  

EPA Science Inventory

Coastal wetlands are among the most fragmented and disturbed ecosystems and the Great Lakes are no exception. One possible result is the observed increase in the presence and dominance of invasive and other opportunistic plant species, such as the common reed (Phragmites australi...

222

Preferential uptake of soil nitrogen forms by grassland plant species  

Microsoft Academic Search

In this study, we assessed whether a range of temperate grassland species showed preferential uptake for different chemical forms of N, including inorganic N and a range of amino acids that commonly occur in temperate grassland soil. Preferential uptake of dual-labelled ( 13C and 15N) glycine, serine, arginine and phenylalanine, as compared to inorganic N, was tested using plants growing

Alexandra Weigelt; Roland Bol; Richard D. Bardgett

2005-01-01

223

Forget the Hoe: Managing Invasive Plant Species with Dynamic Programming\\  

Microsoft Academic Search

Bromus Tectorum is an invasive plant species known to reduce abundance of native perennial grasses, increase fire frequency and intensity, decrease animal performance, and alter microbial communities and ecosystem processes. Specifically, in the Intermountain West, Bromus has been associated with decreases in livestock performance. Land managers use several methods to control invasion, but no previous studies fully integrate the dynamic

Michael Verdone; W. Marshall Frasier

2010-01-01

224

Visual-based plant species identification from crowdsourced data  

E-print Network

Visual-based plant species identification from crowdsourced data Hervé Goëau INRIA, IMEDIA Team a crowdsourcing web application ded- icated to the access of botanical knowledge through auto- mated suggested in spite of various visual difficult queries. 1. INTRODUCTION If agricultural development

Paris-Sud XI, Université de

225

Regional Assessment of Ozone Sensitive Tree Species Using Bioindicator Plants  

Microsoft Academic Search

Tropospheric ozone occurs at phytotoxic levels in the northeastern and mid-Atlantic regions of the United States. Quantifying possible regional-scale impacts of ambient ozone onforest tree species is difficult and is confounded by other factors, such as moisture and light, which influence the uptake of ozone by plants. Biomonitoring provides an approach to document direct foliar injury irrespective of direct measure

John W. Coulston; Gretchen C. Smith; William D. Smith

2003-01-01

226

Emergence and growth of plant species in coal mine soil  

Microsoft Academic Search

Experiments were conducted in the laboratory and greenhouse in Arizona with the following objectives: to evaluate the chemical properties of undisturbed soil, surface-mined coal land (coal mine soil) on the Black Mesa Coal Mine, and Gila loam soil; and to study the emergence of seven plant species in the greenhouse in Gila loam soil and coal mine soil. The pH

A. D. Day; G. F. Mitchell; T. C. Tucker; J. L. Thames

1979-01-01

227

Response of plant species to coal-mine soil materials  

Microsoft Academic Search

A two-year experiment was conducted on the Black Mesa Coal Mine near Kayenta, Arizona to investigate the growth and establishment of seven plant species in unmined soil (undisturbed soil) and coal-mine soil (spoils). Natural rainfall (20 cm\\/yr) and natural rainfull plus sprinkler irrigation (50 cm\\/yr) were the irrigation treatments applied to each soil material.

A. D. Day; T. C. Tucker; J. L. Thamest

1983-01-01

228

Effect of Burning on Germination of Tallgrass Prairie Plant Species  

Microsoft Academic Search

Seeds from 10 prairie plant species of burned and unburned portions of three tallgrass prairies were collected and tested for germinability. Germination of big bluestem (Andropogon gerardii Vitman) consistently averaged higher with burning. Indiangrass (Sorghastrum nutans L.) and sideoats grama [Bouteloua curtipendula (Michx.) Torr.] averaged 5% higher with burning on two of the three sites, although for indiangrass average germination

Sherry R. Rohn; Thomas B. Bragg

1989-01-01

229

Computer-aided plant species identification (CAPSI) based on leaf  

E-print Network

an easy and automatic method that can correctly discriminate and recognize leaf shapes of different the CSS method and applied it to leaf classification with self-intersection. Wang et al. (2002, 2003Computer-aided plant species identification (CAPSI) based on leaf shape matching technique Ji

Hefei Institute of Intelligent Machines

230

The importance of education in managing invasive plant species  

Technology Transfer Automated Retrieval System (TEKTRAN)

Invasive plant species can establish in diverse environments and with the increase in human mobility, they are no longer restricted to isolated pockets in remote parts of the world. Cheat grass (Bromus tectorum L.) in rangelands, purple loosestrife (Lythrum salicaria L.) in wet lands and Canada this...

231

Stimulated rhizodegradation of atrazaine by selected plant species  

Technology Transfer Automated Retrieval System (TEKTRAN)

The efficacy of vegetative buffer strips (VBS) in removing herbicides deposited from surface runoff is related to the ability of plant species to promote rapid herbicide degradation. A growth chamber study was conducted to investigate the rhizodegradation of 14C-atrazine and the relationship of degr...

232

Stimulated Rhizodegradation of Atrazine by Selected Plant Species  

Technology Transfer Automated Retrieval System (TEKTRAN)

The efficacy of vegetative buffer strips (VBS) in removing herbicides from surface runoff is related to the ability of plant species to promote rapid herbicide degradation. A growth chamber study was conducted to investigate the rhizodegradation of 14C-atrazine and the relationship of degradation w...

233

SALINITY-HEAVY METAL INTERACTIONS IN FOUR SALTTOLERANT PLANT SPECIES  

Microsoft Academic Search

The concurrent effect of NaCl salinity and heavy metals [cadmium (Cd), chromium (Cr) and nickel (Ni)] on growth, sodium (Na), and heavy metal accumulation was assessed in four salt tolerant plant species. These were: barley (Hordeum vulgare L.), purslane (Portulaca oleracea L.), Inula crithmoides L., and Plantago coronopus L., all of which have documented potential for use in saline agriculture.

R. A. Zurayk; N. F. Khoury; S. N. Talhouk; R. Z. Baalbaki

2001-01-01

234

ORGANIC PESTICIDE MODIFICATION OF SPECIES INTERACTIONS USING ANNUAL PLANT COMMUNITIES  

EPA Science Inventory

A method is proposed and tested for assessing multispecies responses to three pesticides (atrazine, 2,4,D and malathion). Pesticides were applied at two concentrations, mon model plant communities grown in raised beds using soil containing a natural weed bank. over by species was...

235

Plant species composition and biofuel yields of conservation grasslands  

Technology Transfer Automated Retrieval System (TEKTRAN)

Marginal croplands, such as those in the Conservation Reserve Program (CRP), have been suggested as a source of biomass for biofuel production. However, little is known about the composition of plant species on these conservation grasslands or their potential for ethanol production. Our objective w...

236

Impact of habitat quality on forest plant species colonization  

Microsoft Academic Search

The impact of habitat quality and site history on the recolonization potential of ancient-forest plant species on abandoned farmland was studied in the forest of Ename, Flanders, Belgium. With the exception of a network of fringe relics (linear elements mainly along exploitation roads), our study area was cleared and converted to arable land ca. 1850. From 1869 onward, most fields

Olivier Honnay; Martin Hermy; Pol Coppin

1999-01-01

237

Plant roots and spectroscopic methods – analyzing species, biomass and vitality  

PubMed Central

In order to understand plant functioning, plant community composition, and terrestrial biogeochemistry, it is decisive to study standing root biomass, (fine) root dynamics, and interactions belowground. While most plant taxa can be identified by visual criteria aboveground, roots show less distinctive features. Furthermore, root systems of neighboring plants are rarely spatially segregated; thus, most soil horizons and samples hold roots of more than one species necessitating root sorting according to taxa. In the last decades, various approaches, ranging from anatomical and morphological analyses to differences in chemical composition and DNA sequencing were applied to discern species’ identity and biomass belowground. Among those methods, a variety of spectroscopic methods was used to detect differences in the chemical composition of roots. In this review, spectroscopic methods used to study root systems of herbaceous and woody species in excised samples or in situ will be discussed. In detail, techniques will be reviewed according to their usability to discern root taxa, to determine root vitality, and to quantify root biomass non-destructively or in soil cores holding mixtures of plant roots. In addition, spectroscopic methods which may be able to play an increasing role in future studies on root biomass and related traits are highlighted. PMID:24130565

Rewald, Boris; Meinen, Catharina

2013-01-01

238

Plant roots and spectroscopic methods - analyzing species, biomass and vitality.  

PubMed

In order to understand plant functioning, plant community composition, and terrestrial biogeochemistry, it is decisive to study standing root biomass, (fine) root dynamics, and interactions belowground. While most plant taxa can be identified by visual criteria aboveground, roots show less distinctive features. Furthermore, root systems of neighboring plants are rarely spatially segregated; thus, most soil horizons and samples hold roots of more than one species necessitating root sorting according to taxa. In the last decades, various approaches, ranging from anatomical and morphological analyses to differences in chemical composition and DNA sequencing were applied to discern species' identity and biomass belowground. Among those methods, a variety of spectroscopic methods was used to detect differences in the chemical composition of roots. In this review, spectroscopic methods used to study root systems of herbaceous and woody species in excised samples or in situ will be discussed. In detail, techniques will be reviewed according to their usability to discern root taxa, to determine root vitality, and to quantify root biomass non-destructively or in soil cores holding mixtures of plant roots. In addition, spectroscopic methods which may be able to play an increasing role in future studies on root biomass and related traits are highlighted. PMID:24130565

Rewald, Boris; Meinen, Catharina

2013-01-01

239

Choline but not its derivative betaine blocks slow vacuolar channels in the halophyte Chenopodium quinoa: implications for salinity stress responses.  

PubMed

Activity of tonoplast slow vacuolar (SV, or TPC1) channels has to be under a tight control, to avoid undesirable leak of cations stored in the vacuole. This is particularly important for salt-grown plants, to ensure efficient vacuolar Na(+) sequestration. In this study we show that choline, a cationic precursor of glycine betaine, efficiently blocks SV channels in leaf and root vacuoles of the two chenopods, Chenopodium quinoa (halophyte) and Beta vulgaris (glycophyte). At the same time, betaine and proline, two major cytosolic organic osmolytes, have no significant effect on SV channel activity. Physiological implications of these findings are discussed. PMID:25240200

Pottosin, Igor; Bonales-Alatorre, Edgar; Shabala, Sergey

2014-11-01

240

Host Status of 32 Plant Species to Meloidogyne konaensis  

PubMed Central

A host suitability study of 32 plant species to Meloidogyne konaensis included 54 vegetable cultivars, 12 field crop cultivars, one Gardenia sp., and two weed species. Host suitability was classified according to a M. konaensis reproductive factor: final population density (Pf) (eggs + J2) / initial population density (Pi) (eggs). The number of eggs per gram dry root, and a galling index was also included. Reproductive factor ranges and percentages of plants in the ranges were as follows: Pf/Pi > 5.0, 56.5%; 5.0 ? Pf/Pi > 1.0, 24.6%; 1.0 ? Pf/Pi > 0, 15.9%; and Pf/Pi = 0, 3%. Peanut and 'Decicco' broccoli were nonhosts. Few or no galls were observed on pepper, corn, ginger, waterchestnut, 'Michihili' chinese and 'Marion' market cabbage, although the reproductive factor of M. konaensis was above 5 on these plants. PMID:19279957

Zhang, Fengru; Schmitt, D. P.

1994-01-01

241

Accumulation of K+ and Cs+ in Tropical Plant Species  

NASA Astrophysics Data System (ADS)

Concentrations of K+ and 137Cs+ in tissues of the Citrus aurantifolia were measured both by gamma spectrometry and neutron activation analysis, aiming to understand the behavior of monovalent inorganic cations in plants as well as its capability to store these elements. In contrast to K+, Cs+ ions are not essential elements to plants, what might explain the difference in bioavailability. However, our results have shown that 137Cs+ is positively correlated to 40K+ concentration within tropical plant species, suggesting that these elements might be assimilated in a similar way, and that they pass through the biological cycle together. A simple mathematical model was also proposed to describe the temporal evolution of 40K activity concentration in such tropical woody fruit species. This model exhibited close agreement with the 40K experimental results in the fruit ripening processes of lemon trees.

Velasco, H.; Anjos, R. M.; Zamboni, C. B.; Macario, K. D.; Rizzotto, M.; Cid, A. S.; Medeiros, I. M. A.; Fernández, J.; Rubio, L.; Audicio, P.; Lacerda, T.

2010-08-01

242

Plant species richness and ecosystem multifunctionality in global drylands  

USGS Publications Warehouse

Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and the buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report here on a global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth's land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality and always included species richness as a predictor variable. Our results suggest that the preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands.

Maestre, Fernando T.; Quero, Jose L.; Gotelli, Nicholas J.; Escudero, Adrian; Ochoa, Victoria; Delgado-Baquerizo, Manuel; Garcia-Gomez, Miguel; Bowker, Matthew A.; Soliveres, Santiago; Escolar, Cristina; Garcia-Palacios, Pablo; Berdugo, Miguel; Valencia, Enrique; Gozalo, Beatriz; Gallardo, Antonio; Aguilera, Lorgio; Arredondo, Tulio; Blones, Julio; Boeken, Bertrand; Bran, Donaldo; Conceicao, Abel A.; Cabrera, Omar; Chaieb, Mohamed; Derak, Mchich; Eldridge, David J.; Espinosa, Carlos I.; Florentino, Adriana; Gaitan, Juan; Gatica, M. Gabriel; Ghiloufi, Wahida; Gomez-Gonzalez, Susana; Gutie, Julio R.; Hernandez, Rosa M.; Huang, Xuewen; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Miriti, Maria; Monerris, Jorge; Mau, Rebecca L.; Morici, Ernesto; Naseri, Kamal; Ospina, Abelardo; Polo, Vicente; Prina, Anibal; Pucheta, Eduardo; Ramirez-Collantes, David A.; Romao, Roberto; Tighe, Matthew; Torres-Diaz, Cristian; Val, James; Veiga, Jose P.; Wang, Deli; Zaady, Eli

2012-01-01

243

Tocopherol content and isomers' composition in selected plant species.  

PubMed

We have analyzed leaves of several plant species for the content and isomers' composition of tocopherols and it was found that their content was considerably higher in some cases than previously reported, especially in autumn tree leaves where the average tocopherols' level was in the range of 300-640 microg/g fresh weight and accounted for 40-140% of the chlorophyll amount. The isomers' composition, usually dominated by alpha-tocopherol in leaves, was different in some plant species with a high percentage of gamma-tocopherol (Kalanchoe, lettuce, dodder species, and young maple leaves) or delta-tocopherol (Cuscuta epithymum and Cuscuta japonica). C. japonica was exceptional by the complete absence of alpha-tocopherol. The possible reasons and physiological significance of these observations have been discussed. PMID:18023194

Szyma?ska, Renata; Kruk, Jerzy

2008-01-01

244

Plant species richness and ecosystem multifunctionality in global drylands  

PubMed Central

Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report on the first global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth’s land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality, and always included species richness as a predictor variable. Our results suggest that preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands. PMID:22246775

Maestre, Fernando T.; Quero, José L.; Gotelli, Nicholas J.; Escudero, Adriá; Ochoa, Victoria; Delgado-Baquerizo, Manuel; García-Gómez, Miguel; Bowker, Matthew A.; Soliveres, Santiago; Escolar, Cristina; García-Palacios, Pablo; Berdugo, Miguel; Valencia, Enrique; Gozalo, Beatriz; Gallardo, Antonio; Aguilera, Lorgio; Arredondo, Tulio; Blones, Julio; Boeken, Bertrand; Bran, Donaldo; Conceição, Abel A.; Cabrera, Omar; Chaieb, Mohamed; Derak, Mchich; Eldridge, David J.; Espinosa, Carlos I.; Florentino, Adriana; Gaitán, Juan; Gatica, M. Gabriel; Ghiloufi, Wahida; Gómez-González, Susana; Gutiérrez, Julio R.; Hernández, Rosa M.; Huang, Xuewen; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Miriti, Maria; Monerris, Jorge; Mau, Rebecca L.; Morici, Ernesto; Naseri, Kamal; Ospina, Abelardo; Polo, Vicente; Prina, Aníbal; Pucheta, Eduardo; Ramírez-Collantes, David A.; Romão, Roberto; Tighe, Matthew; Torres-Díaz, Cristian; Val, James; Veiga, José P.; Wang, Deli; Zaady, Eli

2013-01-01

245

Alternate-Fueled Flight: Halophytes, Algae, Bio-, and Synthetic Fuels  

NASA Technical Reports Server (NTRS)

Synthetic and biomass fueling are now considered to be near-term aviation alternate fueling. The major impediment is a secure sustainable supply of these fuels at reasonable cost. However, biomass fueling raises major concerns related to uses of common food crops and grasses (some also called "weeds") for processing into aviation fuels. These issues are addressed, and then halophytes and algae are shown to be better suited as sources of aerospace fuels and transportation fueling in general. Some of the history related to alternate fuels use is provided as a guideline for current and planned alternate fuels testing (ground and flight) with emphasis on biofuel blends. It is also noted that lessons learned from terrestrial fueling are applicable to space missions. These materials represent an update and additions to the Workshop on Alternate Fueling Sustainable Supply and Halophyte Summit at Twinsburg, OH, Oct. 17 to 18, 2007 (ref. 1).

Hendricks, R. C.

2007-01-01

246

Alternate-Fueled Flight: Halophytes, Algae, Bio-, and Synthetic Fuels  

NASA Technical Reports Server (NTRS)

Synthetic and biomass fueling are now considered to be near-term aviation alternate fueling. The major impediment is a secure sustainable supply of these fuels at reasonable cost. However, biomass fueling raises major concerns related to uses of common food crops and grasses (some also called "weeds") for processing into aviation fuels. These issues are addressed, and then halophytes and algae are shown to be better suited as sources of aerospace fuels and transportation fueling in general. Some of the history related to alternate fuels use is provided as a guideline for current and planned alternate fuels testing (ground and flight) with emphasis on biofuel blends. It is also noted that lessons learned from terrestrial fueling are applicable to space missions. These materials represent an update (to 2009) and additions to the Workshop on Alternate Fueling Sustainable Supply and Halophyte Summit at Twinsburg, Ohio, October 17 to 18, 2007.

Hendricks, R. C.

2012-01-01

247

Reprints Available from the Halophyte Biotechnology Center  

E-print Network

roemerianus and Juncus gerardii. In Vitro Cellular and Developmental Biology ­ Plant 41:274-280. Wu, J., D, and J.L. Gallagher. 2005. Tissue culture and plant regeneration of the salt marsh monocots Juncus

Firestone, Jeremy

248

Mercury uptake and accumulation by four species of aquatic plants.  

PubMed

The effectiveness of four aquatic plants including water hyacinth (Eichornia crassipes), water lettuce (Pistia stratiotes), zebra rush (Scirpus tabernaemontani) and taro (Colocasia esculenta) were evaluated for their capabilities in removing mercury from water. The plants were exposed to concentrations of 0 mg/L, 0.5 mg/L or 2 mg/L of mercury for 30 days. Assays were conducted using both Microtox (water) and cold vapor Atomic Absorption Spectroscopy (AAS) (roots and water). The Microtox results indicated that the mercury induced acute toxicity had been removed from the water. AAS confirmed an increase of mercury within the plant root tissue and a corresponding decrease of mercury in the water. All species of plants appeared to reduce mercury concentrations in the water via root uptake and accumulation. Water lettuce and water hyacinth appeared to be the most effective, followed by taro and zebra rush, respectively. PMID:16781033

Skinner, Kathleen; Wright, Nicole; Porter-Goff, Emily

2007-01-01

249

Plant species richness increases phosphatase activities in an experimental grassland  

NASA Astrophysics Data System (ADS)

Plant species richness has been shown to increase aboveground nutrient uptake requiring the mobilization of soil nutrient pools. For phosphorus (P) the underlying mechanisms for increased P release in soil under highly diverse grassland mixtures remain obscure because aboveground P storage and concentrations of inorganic and organic P in soil solution and differently reactive soil P pools are unrelated (Oelmann et al. 2011). The need of plants and soil microorganisms for P can increase the exudation of enzymes hydrolyzing organically bound P (phosphatases) which might represent an important release mechanism of inorganic P in a competitive environment such as highly diverse grassland mixtures. Our objectives were to test the effects of i) plant functional groups (legumes, grasses, non-leguminous tall and small herbs), and of (ii) plant species richness on microbial P (Pmic) and phosphatase activities in soil. In autumn 2013, we measured Pmic and alkaline phosphomonoesterase and phosphodiesterase activities in soil of 80 grassland mixtures comprising different community compositions and species richness (1, 2, 4, 8, 16, 60) in the Jena Experiment. In general, Pmic and enzyme activities were correlated (r = 0.59 and 0.46 for phosphomonoesterase and phosphodiesterase activities, respectively; p

Hacker, Nina; Wilcke, Wolfgang; Oelmann, Yvonne

2014-05-01

250

Stimulated rhizodegradation of atrazine by selected plant species.  

PubMed

The efficacy of vegetative buffer strips (VBS) in removing herbicides deposited from surface runoff is related to the ability of plant species to promote rapid herbicide degradation. A growth chamber study was conducted to compare C-atrazine (ATR) degradation profiles in soil rhizospheres from different forage grasses and correlate ATR degradation rates and profiles with microbial activity using three soil enzymes. The plant treatments included: (i) orchardgrass ( L.), (ii) smooth bromegrass ( Leyss.), (iii) tall fescue ( Schreb.), (iv) Illinois bundle flower (), (v) perennial ryegrass ( L.), (vi) switchgrass ( L.), and (vii) eastern gamagrass (). Soil without plants was used as the control. The results suggested that all plant species significantly enhanced ATR degradation by 84 to 260% compared with the control, but eastern gamagrass showed the highest capability for promoting biodegradation of ATR in the rhizosphere. More than 90% of ATR was degraded in the eastern gamagrass rhizosphere compared with 24% in the control. Dealkylation of atrazine strongly correlated with increased enzymatic activities of ?-glucosidase (GLU) ( = 0.96), dehydrogenase (DHG) ( = 0.842), and fluorescein diacetate (FDA) hydrolysis ( = 0.702). The incorporation of forage species, particularly eastern gamagrass, into VBS designs will significantly promote the degradation of ATR transported into the VBS by surface runoff. Microbial parameters widely used for assessment of soil quality, e.g., DHG and GLU activities, are promising tools for evaluating the overall degradation potential of various vegetative buffer designs for ATR remediation. PMID:21712580

Lin, Chung-Ho; Lerch, Robert N; Kremer, Robert J; Garrett, Harold E

2011-01-01

251

Species differences in whole plant carbon balance following winter dormancy in Alaskan tundra plants  

SciTech Connect

We froze ramets of seven vascular plant species and a mixed community of mosses common to upland tussock tundra for several months, then measured whole-plant photosynthesis and respiration in a growth chamber under simulated spring conditions, to examine whole plant carbon metabolism following winter dormancy. In addition, respiration and photosynthesis of aboveground stems and leaves were measured in the field in a spatial gradient away from a melting snowbank, at comparable developmental stages. Species differences in early respiration were not pronounced, but large differences were seen once development of leaves began. Root development in deciduous shrubs delayed their attainment of a positive whole plant carbon balance compared to that seen in aboveground stems and leaves alone, and partially compensated for differences in photosynthetic rates between shrubs and other species. Temporal patterns of carbon metabolism during spring growth may affect competitive balance in tussock tundra and vegetation response to global change.

Bret-Harte, M.S.; Chapin, F.S. III [Univ. of California, Berkeley, CA (United States)

1995-09-01

252

How many species of flowering plants are there?  

PubMed Central

We estimate the probable number of flowering plants. First, we apply a model that explicitly incorporates taxonomic effort over time to estimate the number of as-yet-unknown species. Second, we ask taxonomic experts their opinions on how many species are likely to be missing, on a family-by-family basis. The results are broadly comparable. We show that the current number of species should grow by between 10 and 20 per cent. There are, however, interesting discrepancies between expert and model estimates for some families, suggesting that our model does not always completely capture patterns of taxonomic activity. The as-yet-unknown species are probably similar to those taxonomists have described recently—overwhelmingly rare and local, and disproportionately in biodiversity hotspots, where there are high levels of habitat destruction. PMID:20610425

Joppa, Lucas N.; Roberts, David L.; Pimm, Stuart L.

2011-01-01

253

Vascular plant species richness in Alaskan arctic tundra: the importance of soil pH  

E-print Network

Vascular plant species richness in Alaskan arctic tundra: the importance of soil pH LAURA GOUGH hypothesized that vas- cular plant species density, richness and diversity in Alaskan tundra would for maintaining higher species numbers. 3 The 11 000-year-old site supported more vascular plant species than

Royer, Dana

254

Different Arbuscular Mycorrhizal Fungal Species Are Potential Determinants of Plant Community Structure  

Microsoft Academic Search

Almost all natural plant communities contain arbuscular mycorrhizal fungi (AMF). We hypothesized that the species composition of AMF communities could have the potential to determine plant community structure if the growth response to different AMF species or to communities of AMF species varies among plant species. To test the existence of such a differential response we conducted a pot experiment

Thomas Boller; Andres Wiemken; Ian R. Sanders

1998-01-01

255

Methylated arsenic species in plants originate from soil microorganisms.  

PubMed

• Inorganic arsenic (iAs) is a ubiquitous human carcinogen, and rice (Oryza sativa) is the main contributor to iAs in the diet. Methylated pentavalent As species are less toxic and are routinely found in plants; however, it is currently unknown whether plants are able to methylate As. • Rice, tomato (Solanum lycopersicum) and red clover (Trifolium pratense) were exposed to iAs, monomethylarsonic acid (MMA(V)), or dimethylarsinic acid (DMA(V)), under axenic conditions. Rice seedlings were also grown in two soils under nonsterile flooded conditions, and rice plants exposed to arsenite or DMA(V) were grown to maturity in nonsterile hydroponic culture. Arsenic speciation in samples was determined by HPLC-ICP-MS. • Methylated arsenicals were not found in the three plant species exposed to iAs under axenic conditions. Axenically grown rice was able to take up MMA(V) or DMA(V), and reduce MMA(V) to MMA(III) but not convert it to DMA(V). Methylated As was detected in the shoots of soil-grown rice, and in rice grain from nonsterile hydroponic culture. GeoChip analysis of microbial genes in a Bangladeshi paddy soil showed the presence of the microbial As methyltransferase gene arsM. • Our results suggest that plants are unable to methylate iAs, and instead take up methylated As produced by microorganisms. PMID:22098145

Lomax, Charlotte; Liu, Wen-Ju; Wu, Liyou; Xue, Kai; Xiong, Jinbo; Zhou, Jizhong; McGrath, Steve P; Meharg, Andrew A; Miller, Anthony J; Zhao, Fang-Jie

2012-02-01

256

Variation in grazing tolerance among three tallgrass prairie plant species.  

PubMed

Three tallgrass prairie plant species, two common perennial forbs (Artemisia ludoviciana and Aster ericoides [Asteraceae]) and a dominant C(4) perennial grass (Sorghastrum nutans) were studied under field and greenhouse conditions to evaluate interspecific variation in grazing tolerance (compensatory growth capacity). Adaptation to ungulate grazing was also assessed by comparing defoliation responses of plants from populations with a 25-yr history of no grazing or moderate ungulate grazing. Under field conditions, all three species showed significant reductions in shoot relative growth rates (RGR), biomass, and reproduction with defoliation. In the two forbs, clipping resulted in negative shoot RGR and reductions in both number and length of shoot branches per ramet. Sorghastrum nutans maintained positive RGR under defoliation due to a compensatory increase in leaf production. Defoliation reduced rhizome production in A. ericoides and S. nutans, but not in A. ludoviciana. Clipping significantly reduced sexual reproductive allocation in all three species, although S. nutans showed a smaller reduction than the forbs. All three species showed similar responses to defoliation in burned and unburned sites. Under greenhouse conditions, a similar clipping regimen resulted in smaller reductions in growth and reproduction than those observed in the field. For all three species, the grazing tolerance indices calculated under natural field conditions were significantly lower than those estimated from greenhouse-grown plants, and the interspecific patterns of grazing tolerance were different. Aster ericoides exhibited the highest overall defoliation tolerance under greenhouse conditions, followed by S. nutans. Artemisia ludoviciana, the only study species that is typically not grazed by ungulates in the field, showed the lowest grazing tolerance. In the field experiment S. nutans showed the highest grazing tolerance and the two forbs had similar low tolerance indices. These patterns indicate that, despite high compensatory growth potential, limited resource availability and competition in the field significantly reduce the degree of compensation and alter interspecific differences in grazing tolerance among prairie plants. In all three species, defoliation suppressed sexual reproduction more than growth or vegetative reproduction. Significant interactions between plant responses to defoliation and site of origin (historically grazed or ungrazed sites) for some response variables (root/shoot ratios, rhizome bud initiation, and reproductive allocation) indicated some degree of population differentiation and genetic adaptation in response to a relatively short history of ungulate grazing pressure. The results of this study indicate that patterns of grazing tolerance in tallgrass prairie are both genetically based and also environmentally dependent. PMID:21665591

Damhoureyeh, Said A; Hartnett, David C

2002-10-01

257

The role of succulent halophytes in the water balance of salt marsh rodents  

Microsoft Academic Search

The role of succulent halophytes in the water balance and ecology of salt marsh rodents is dependent upon an evaluation of the composition of the available sources and the physiological properties of their potential consumers. Studies of the osmotic properties of succulent halophytes from southern California coastal salt marshes are presented, together with experiments regarding the utilization of Common Pickleweed

Harry N. Coulombe

1970-01-01

258

Nutrient relations of the halophytic shrub, Sarcobatus vermiculatus, along a soil salinity gradient  

Microsoft Academic Search

Recent water level declines of a saline and alkaline lake (Mono Lake, California, USA) have exposed large areas of former lake bottom substrates that have been sparsely colonized by the halophytic shrub, Sarcobatus vermiculatus. To increase understanding of the interaction of salt and nutrient relations in halophytes we investigated spatial and seasonal patterns of leaf elemental composition and growth for

Lisa A. Donovan; James H. Richards; E. Joy Schaber

1997-01-01

259

Seed longevity and germination characteristics of six fen plant species.  

PubMed

Fens are among the most threatened habitats in Europe as their area has decreased considerably in the last centuries. For successful management and restoration conservationists need detailed knowledge about seed bank formation and seed longevity of plants, as these features are closely related to successional and vegetation dynamical processes. I analysed seed longevity and the germination characteristics of six fen plant species by seed burial experiments. Based on seed weight, seed bank was expected for long-term persistent for the light-seeded Schoenus nigricans, Carex appropinquata, C. pseudocyperus, C. davalliana and Peucedanum palustre and also that for the medium-seeded Cicuta virosa. It was proved that, the latter two species have short-term persistent seed banks, while Carex pseudocyperus has a transient seed bank, therefore these species may only have a limited role in restoration from seed banks. It was found that Schoenus nigricans, Carex appropinquata and C. davalliana have persistent seed banks, because some of their four-year-old seeds have emerged. Fresh seeds had low germination rate in all studied species and majority of seeds emerged after winter, except for Carex pseudocyperus. After the germination peak in spring, the majority of the ungerminated seeds of Schoenus nigricans, Peucedanum palustre, Carex appropinquata, C. davalliana and Cicuta virosa entered a secondary dormancy phase that was broken in autumn. I found the seasonal emergence of the latter three species highly similar. PMID:21565777

Tatár, S

2010-01-01

260

Cupriavidus plantarum sp. nov., a plant-associated species.  

PubMed

During a survey of plant-associated bacteria in northeast Mexico, a group of 13 bacteria was isolated from agave, maize and sorghum plants rhizosphere. This group of strains was related to Cupriavidus respiraculi (99.4 %), but a polyphasic investigation based on DNA-DNA hybridization analysis, other genotypic studies and phenotypic features showed that this group of strains actually belongs to a new Cupriavidus species. Consequently, taking all the results together, the description of Cupriavidus plantarum sp. nov. is proposed. PMID:25098225

Estrada-de Los Santos, Paulina; Solano-Rodríguez, Roosivelt; Matsumura-Paz, Lucía Tomiko; Vásquez-Murrieta, María Soledad; Martínez-Aguilar, Lourdes

2014-11-01

261

Phylogenetic placement of plant pathogenic Sclerotium species among teleomorph genera.  

PubMed

Phylogenetic analyses and morphological characteristics were used to assess the taxonomic placement of eight plant-pathogenic Sclerotium species. Members of this genus produce only sclerotia and no fruiting bodies or spores, so Sclerotium species have been difficult to place taxonomically. Sequences of rDNA large subunit (LSU) and internal transcribed spacer (ITS) regions were determined for isolates of Sclerotium cepivorum, S. coffeicola, S. denigrans, S. hydrophilum, Ceratorhiza oryzae-sativae, S. perniciosum, S. rhizodes, S. rolfsii and S. rolfsii var. delphinii. Parsimony analysis grouped two species previously thought to be in the Basidiomycota, S. denigrans and S. perniciosum, within the Ascomycota; these species were found to have affinities with the teleomorph genera Sclerotinia and Stromatinia and the asexual Sclerotium cepivorum, which was known earlier to be related to Sclerotinia species. The other Sclerotium species were placed in one of two basidiomycetous groups, genera Athelia or Ceratobasidium. Based on rDNA analysis and morphology the basidiomycetous Sclerotium hydrophilum and S. rhizodes were transferred to genus Ceratorhiza, the anamorph of Ceratobasidium species. Sclerotium coffeicola was found to be close to S. rolfsii var. delphinii and S. rolfsii var. rolfsii, which was shown earlier to have an Athelia teleomorph. PMID:20361501

Xu, Zhihan; Harrington, Thomas C; Gleason, Mark L; Batzer, Jean C

2010-01-01

262

Corridors Increase Plant Species Richness at Large Scales  

SciTech Connect

Habitat fragmentation is one of the largest threats to biodiversity. Landscape corridors, which are hypothesized to reduce the negative consequences of fragmentation, have become common features of ecological management plans worldwide. Despite their popularity, there is little evidence documenting the effectiveness of corridors in preserving biodiversity at large scales. Using a large-scale replicated experiment, we showed that habitat patches connected by corridors retain more native plant species than do isolated patches, that this difference increases over time, and that corridors do not promote invasion by exotic species. Our results support the use of corridors in biodiversity conservation.

Damschen, Ellen I.; Haddad, Nick M.; Orrock,John L.; Tewksbury, Joshua J.; Levey, Douglas J.

2006-09-01

263

Constitutive high-level SOS1 expression and absence of HKT1;1 expression in the salt-accumulating halophyte Salicornia dolichostachya.  

PubMed

We investigated the effects of salinity on ion accumulation and expression of candidate salt tolerance genes in the highly tolerant salt accumulating halophyte Salicornia dolichostachya and the taxonomically related glycophytic Spinacia oleracea. S. dolichostachya, in comparison with S. oleracea, constitutively expressed SOS1 at a high level, but did not detectably express HKT1;1. These findings suggest that the constitutive high level of shoot salt accumulation in S. dolichostachya is accomplished through enhancement of SOS1-mediated Na(+) xylem loading, in combination with complete suppression of HKT1;1-mediated Na(+) retrieval from the xylem. Our findings demonstrate the importance of gene expression comparisons between highly tolerant halophytes and taxonomically related glycophytes to improve the understanding of mechanisms of Na(+) movement and salt tolerance in plants. PMID:25804817

Katschnig, D; Bliek, T; Rozema, J; Schat, H

2015-05-01

264

New evidence for electrotropism in some plant species  

NASA Astrophysics Data System (ADS)

The ever-present global Atmospheric Electrical F ield (AEF) is used by many plant species. There are many natural habitats with electrotropic plants and habitats with no AEF. The plants growing there are not electrotropic, like the plants growing under the canopies of the trees or the Arecibo radio telescope. Examples are given of different plants which belong to one or the other class, and the criteria how to distinguish them. In addition to natural habitat observations, laboratory experiments were run in search of the sensitivity to electrotropic effect in different electric field intensities and directions. It was established that in very strong fields (of the order of 1 MV/m) all plants respond immediately to the field. This type of reaction is due to the Coulomb forces, but electrotropism depends on electric field interaction with ions in plant tissues. We use a "reference field" (130 V/m) and stronger fields in the several kV/m range which enhance plant growth rate and size similar to plant growth hormones. Surprising effects were also observed with reversed field polarity. In conclusion electrotropic pl nts deprived of the electrical field do not develop asa expected, as can be seen in BIOSPHERE 2. It was a sad example of what happens when one forgets to provide the plants with this vital natural environmental factor. Electrical fields of different intensity and direction are cheap and easy to generate. More plants were investigated in order to verify their response to electrical fields. Effect of several kV/m horizontal fields, was compared with the vertical 130 V/m field (ued as a reference) and it was shown that electrotropic sensitivity can be found easily. Surprisingly even the nonelectrotropic plants, whose initial growth rate does not depend on the field strength, when they develop leaves begin to lean towards the positive electrode, and become elect rotropic. Ground based fitotron experiments enable us to select cheaply plants which shall be suitable for food production in space using electical fields to restore to plants the sense of direction of growth.

Gorgolewski, S.; Rozej, B.

265

Planting intensity, residence time, and species traits determine invasion success of alien woody species.  

PubMed

We studied the relative importance of residence time, propagule pressure, and species traits in three stages of invasion of alien woody plants cultivated for about 150 years in the Czech Republic, Central Europe. The probability of escape from cultivation, naturalization, and invasion was assessed using classification trees. We compared 109 escaped-not-escaped congeneric pairs, 44 naturalized-not-naturalized, and 17 invasive-not-invasive congeneric pairs. We used the following predictors of the above probabilities: date of introduction to the target region as a measure of residence time; intensity of planting in the target area as a proxy for propagule pressure; the area of origin; and 21 species-specific biological and ecological traits. The misclassification rates of the naturalization and invasion model were low, at 19.3% and 11.8%, respectively, indicating that the variables used included the major determinants of these processes. The probability of escape increased with residence time in the Czech Republic, whereas the probability of naturalization increased with the residence time in Europe. This indicates that some species were already adapted to local conditions when introduced to the Czech Republic. Apart from residence time, the probability of escape depends on planting intensity (propagule pressure), and that of naturalization on the area of origin and fruit size; it is lower for species from Asia and those with small fruits. The probability of invasion is determined by a long residence time and the ability to tolerate low temperatures. These results indicate that a simple suite of factors determines, with a high probability, the invasion success of alien woody plants, and that the relative role of biological traits and other factors is stage dependent. High levels of propagule pressure as a result of planting lead to woody species eventually escaping from cultivation, regardless of biological traits. However, the biological traits play a role in later stages of invasion. PMID:19886483

Pysek, Petr; Krivánek, Martin; Jarosík, Vojtech

2009-10-01

266

Influence of herbivores on a perennial plant: variation with life history stage and herbivore species  

Microsoft Academic Search

Herbivores have diverse impacts on their host plants, potentially altering survival, growth, fecundity, and other aspects of plant performance. Especially for longer-lived plant species, the effects of a single herbivore species can vary markedly throughout the life of the host plant. In addition, the effects of herbivory during any given life history stage of a host plant may also vary

Peter J. Warner; Hall J. Cushman

2002-01-01

267

The role of antioxidant responses on the tolerance range of extreme halophyte Salsola crassa grown under toxic salt concentrations.  

PubMed

Salsola crassa (Amaranthaceae) is an annual halophytic species and naturally grows in arid soils that are toxic to most plants. In order to study the effects of salinity on their antioxidant system and to determine the tolerance range against salt stress, S. crassa seeds were grown with different concentrations of NaCl (0, 250, 500, 750, 1000, 1250 and 1500mM) for short (15d) and long-term (30d). Results showed that growth (RGR), water content (RWC) and osmotic potential (??) decreased and, proline content (Pro) increased at prolonged salt treatment. Unlike K(+) and Ca(2+) contents, S. crassa highly accumulated Na(+) and Cl(-) contents. Chlorophyll fluorescence (Fv/Fm) only decreased in response to 1500mM NaCl at 30d. No salt stimulation of superoxide anion radical (O2(•-)) content was observed in plants treated with the range of 0-500mM NaCl during the experimental period. NaCl increased superoxide dismutase (SOD) activity depending on intensities of Mn-SOD and Fe-SOD isozymes except in 1500mM NaCl-treated plants at 30d. In contrast to catalase (CAT), peroxidase (POX) activity increased throughout the experiment. Also, salinity caused an increase in glutathione reductase (GR) and glutathione peroxidase (GPX) and decreased in ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR) at 15d. Both total ascorbate (tAsA) and glutathione (tGlut) contents significantly increased in treated plants with 1000-1500mM NaCl at 15d. After 0-1000mM NaCl stress, H2O2 and TBARS contents were similar to control groups at 15d, which were consistent with the increased antioxidant activity (POX, GR and GPX). However, H2O2 content was more pronounced at 30d. Therefore, S. crassa exhibited inductions in lipid peroxidation (TBARS content) in response to extreme salt concentrations. These results suggest that S. crassa is tolerant to salt-induced damage at short-term treatments as well as extreme salt concentrations. PMID:25193881

Yildiztugay, Evren; Ozfidan-Konakci, Ceyda; Kucukoduk, Mustafa

2014-12-01

268

Pollinators visit related plant species across 29 plant–pollinator networks  

PubMed Central

Understanding the evolution of specialization in host plant use by pollinators is often complicated by variability in the ecological context of specialization. Flowering communities offer their pollinators varying numbers and proportions of floral resources, and the uniformity observed in these floral resources is, to some degree, due to shared ancestry. Here, we find that pollinators visit related plant species more so than expected by chance throughout 29 plant–pollinator networks of varying sizes, with “clade specialization” increasing with community size. As predicted, less versatile pollinators showed more clade specialization overall. We then asked whether this clade specialization varied with the ratio of pollinator species to plant species such that pollinators were changing their behavior when there was increased competition (and presumably a forced narrowing of the realized niche) by examining pollinators that were present in at least three of the networks. Surprisingly, we found little evidence that variation in clade specialization is caused by pollinator species changing their behavior in different community contexts, suggesting that clade specialization is observed when pollinators are either restricted in their floral choices due to morphological constraints or innate preferences. The resulting pollinator sharing between closely related plant species could result in selection for greater pollinator specialization. PMID:25360269

Vamosi, Jana C; Moray, Clea M; Garcha, Navdeep K; Chamberlain, Scott A; Mooers, Arne Ø

2014-01-01

269

Origin of floral isolation between ornithophilous and sphingophilous plant species.  

PubMed

Three plant groups in temperate western North America contain closely related ornithophilous and sphingophilous species: the Aquilegia formosa/Aquilegia caerulea group (Ranunculaceae), the Ipomopsis aggregata group (Polemoniaceae), and the Diplacus longiflorus group (Scrophulariaceae). The ornithophilous and sphingophilous species are products of allopatric speciation on the diploid level. Geographical races which are adapted to one class of pollinators in one area where these pollinators are abundant and effective and to another class of pollinators in another geographically isolated area (pollination races) represent a probable intermediate stage in the process of allopatric speciation. Mechanical and ethological isolation (collectively, floral isolation) is a byproduct of the divergence in pollination systems. Selection for reproductive isolation per se has not played any detectable role in the origin of the floral isolation in the three plant groups. PMID:11607421

Grant, V

1993-08-15

270

Hybrid Viability and Fertility in Co-occuring Plant Species  

NASA Astrophysics Data System (ADS)

Similar species of plants can co-exist due to reproductive barriers that keep them from hybridizing. In the case of Lasthenia gracilis and L. californica, certain reproductive barriers allow them to co-exist at Jasper Ridge without hybridization. The two species are locally adapted to different regions of the same hillside, and have slight differences in flowering time but hybrids can be created at low rate in the green house. We tested the viability and fertility of green house produced hybrids to quantify post-zygotic reproductive isolation at Jasper Ridge. We planted 10 hybrid seeds and 10 control seeds from 11 different families. We measured the percent germination, survival to flowering and pollen fertility of the seeds. We expect lower germination, lower survival to flowering, and lower pollen viability of hybrid seeds as compared to control seeds.

Hernandez, E.; Garcia, C.; Yost, J.

2012-12-01

271

Origin of floral isolation between ornithophilous and sphingophilous plant species.  

PubMed Central

Three plant groups in temperate western North America contain closely related ornithophilous and sphingophilous species: the Aquilegia formosa/Aquilegia caerulea group (Ranunculaceae), the Ipomopsis aggregata group (Polemoniaceae), and the Diplacus longiflorus group (Scrophulariaceae). The ornithophilous and sphingophilous species are products of allopatric speciation on the diploid level. Geographical races which are adapted to one class of pollinators in one area where these pollinators are abundant and effective and to another class of pollinators in another geographically isolated area (pollination races) represent a probable intermediate stage in the process of allopatric speciation. Mechanical and ethological isolation (collectively, floral isolation) is a byproduct of the divergence in pollination systems. Selection for reproductive isolation per se has not played any detectable role in the origin of the floral isolation in the three plant groups. PMID:11607421

Grant, V

1993-01-01

272

Consequences of plant invasions on compartmentalization and species' roles in plant-pollinator networks.  

PubMed

Compartmentalization-the organization of ecological interaction networks into subsets of species that do not interact with other subsets (true compartments) or interact more frequently among themselves than with other species (modules)-has been identified as a key property for the functioning, stability and evolution of ecological communities. Invasions by entomophilous invasive plants may profoundly alter the way interaction networks are compartmentalized. We analysed a comprehensive dataset of 40 paired plant-pollinator networks (invaded versus uninvaded) to test this hypothesis. We show that invasive plants have higher generalization levels with respect to their pollinators than natives. The consequences for network topology are that-rather than displacing native species from the network-plant invaders attracting pollinators into invaded modules tend to play new important topological roles (i.e. network hubs, module hubs and connectors) and cause role shifts in native species, creating larger modules that are more connected among each other. While the number of true compartments was lower in invaded compared with uninvaded networks, the effect of invasion on modularity was contingent on the study system. Interestingly, the generalization level of the invasive plants partially explains this pattern, with more generalized invaders contributing to a lower modularity. Our findings indicate that the altered interaction structure of invaded networks makes them more robust against simulated random secondary species extinctions, but more vulnerable when the typically highly connected invasive plants go extinct first. The consequences and pathways by which biological invasions alter the interaction structure of plant-pollinator communities highlighted in this study may have important dynamical and functional implications, for example, by influencing multi-species reciprocal selection regimes and coevolutionary processes. PMID:24943368

Albrecht, Matthias; Padrón, Benigno; Bartomeus, Ignasi; Traveset, Anna

2014-08-01

273

Reactive Oxygen Species, Oxidative Stress and Plant Ion Channels  

Microsoft Academic Search

\\u000a Reactive oxygen species (ROS) are important toxic and regulatory agents in plants. They are produced in response to a number\\u000a of stimuli, including major biotic and abiotic stresses. Disruption of respiratory and photosynthetic electron transport chains,\\u000a as well as activation of NADPH oxidases (NOXs) and peroxidases, is a major reason for ROS generation and accumulation during\\u000a stress conditions. ROS production

Vadim Demidchik

274

Tocopherol content and isomers' composition in selected plant species  

Microsoft Academic Search

We have analyzed leaves of several plant species for the content and isomers' composition of tocopherols and it was found that their content was considerably higher in some cases than previously reported, especially in autumn tree leaves where the average tocopherols' level was in the range of 300–640?g\\/g fresh weight and accounted for 40–140% of the chlorophyll amount. The isomers'

Renata Szyma?ska; Jerzy Kruk

2008-01-01

275

Does phosphorus limitation promote species-rich plant communities?  

Microsoft Academic Search

It is known that the number of limiting nutrients may affect the species richness of plant communities, but it is unclear\\u000a whether the type of nutrient limitation is also important. I place the results from a study in Patagonia (elsewhere in this\\u000a issue) in the context of the number and types of nutrients that are limiting. I present four mechanisms

Harry Olde Venterink

276

Nuclear DNA content of some important plant species  

Microsoft Academic Search

Nuclear DNA contents of more than 100 important plant species were measured by flow cytometry of isolated nuclei stained with\\u000a propidium iodide.Arabidopsis exhibits developmentally regulated multiploidy and has a 2C nuclear DNA content of 0.30 pg (145 Mbp\\/1C), twice the value\\u000a usually cited. The 2C value for rice is only about three times that ofArabidopsis. Tomato has a 2C value

K. Arumuganathan; E. D. Earle

1991-01-01

277

Reactive Oxygen Species in Plant–Pathogen Interactions  

Microsoft Academic Search

Reactive oxygen species (ROS), superoxide, hydrogen peroxide and nitric oxide are produced at all levels of resistance reactions\\u000a in plants. In basal resistance, they are linked to papilla formation and the assembly of barriers. In the hypersensitive response,\\u000a they may be linked to programmed cell death, and in systemic acquired resistance, they interact with salicylate in signalling.\\u000a Despite this importance,

G. Paul Bolwell; Arsalan Daudi

278

Biodegradation of 2,4-dinitrotoluene by different plant species.  

PubMed

Over the past century, rapid growth of population, mining and industrialization significantly contributed to extensive soil, air and water contamination. The 2,4-dinitrotoluene (2,4-DNT), used mostly as explosive, belongs to the hazardous xenobiotics. Soils and waters contaminated with 2,4-DNT may be cleaned by phytoremediation using suitable plant species. The ability of crop plants (hemp, flax, sunflower and mustard) to germinate and grow on soils contaminated with 2,4-DNT was compared. Stimulation of their growth was found at 0.252 mg/g 2,4-DNT. The lethal concentration for the growth for these species was around 1 mg/g. In hydropony, the above mentioned species were able to survive 200 mg/l 2,4-DNT, the concentration close to maximal solubility of 2,4-DNT in water. Metabolism of 2,4-DNT was tested using suspension culture of soapwort and reed. The degradation products 2-aminonitrotoluene and 4-aminonitrotoluene were found both in the medium and in the acetone extract of plant cells. The test showed that the toxicity of these metabolites was higher than the toxicity of the parent compound, but 2,4-diaminotoluene, the product of next reduction step, was less toxic in the concentration range tested (0-200 mg/l). PMID:25463853

Podlipná, Radka; Pospíšilová, Blanka; Van?k, Tomáš

2015-02-01

279

Arsenic species: effects on and accumulation by tomato plants.  

PubMed

The uptake of arsenic (As) species by Lycopersicum esculentum, growing under soilless culture conditions, was studied. A 4 x 3 x 2 factorial experiment was conducted with four As species (arsenite, arsenate, methylarsonate, and dimethylarsinate), three As concentrations (1, 2, and 5 mg L(-)(1)) and two tomato cultivars (Marmande and Muchamiel). The phytoavailability and phytotoxicity were primarily determined by the As species. The concentrations of As in plant increased significantly with increasing As concentration in solution. Both MA and DMA showed a higher upward translocation than arsenite and arsenate, and treatments with MA and DMA clearly reduced plant growth and fruit yield. The As concentration in tomatoes treated with arsenite or arsenate were within the range considered normal in food crops; however, the As concentration in tomatoes treated with MA and DMA were close to or even above the maximum limit. When tomato plants are exposed to high concentrations of As in nutrient solutions, they may uptake As to concentrations unacceptable for human food. PMID:10552445

Burló, F; Guijarro, I; Carbonell-Barrachina, A A; Valero, D; Martínez-Sánchez, F

1999-03-01

280

[Plant anatomical and phytochemical evaluation of Salvia species].  

PubMed

Plant-anatomical and phytochemical investigations were carried out on three Salvia species: S.officinalis L., S.sclarea L., S.pratensis L. It was established that the structure of the glandular hairs of the three species doesn't differ from each other but the characteristics of the covering hairs are different. The covering hairs of sage (Salvia officinalis) consist of 1-4 cells and have protective function. The hairs of the other two Salvia species are bristle hairs. The highest essential oil content was found in sage and the lowest one in S. pratensis. The qualitative and quantitative composition of the essential oils of Salvia species was also various but the qualitative composition of leaf, calix and petal of the same Salvia species was characteristical standard; significant differences were found only in their quantitative composition. Sclareol diterpene alcohol was the main component of the hexane extract obtained from clary sage flowering herb. In polyphenol ingredients Salvia officinalis was the richest. The results demonstrated that the 20% ethanol is the best of the 20, 40, 70% alcoholic solvents, for the extraction of polyphenol compounds. It was established that the rosmarinic acid depside was the main component of polyphenols. Mineral elements were also analysed in the Salvia species leaves as well in the alcoholic and wateric extracts of sage. The magnesium content was considerable in S. pratensis, the zinc content was the highest in S. officinalis. PMID:9703703

Then, M; Lemberkovics, E; Marczal, G; Szentmihályi, K; Szöke, E

1998-05-01

281

Occurrence and distribution of Legionella species in composted plant materials.  

PubMed Central

Legionellae were found in many samples of composted plant matter obtained from home gardeners and from facilities which undertook bulk composting. The predominant species isolated from these composts was Legionella pneumophila, the strains of which belonged to serogroups other than serogroup 1. Other Legionella species were present in many samples. Legionella longbeachae serogroup 1, which is implicated in human infections in South Australia, was present in samples obtained from two of six facilities composting large volumes of material and from 3 of 30 gardeners. Many of the species or strains isolated from composts have not been implicated as causative agents of legionellosis in South Austrailia, but some cause infection in healthy and immunosuppressed persons. PMID:11001749

Hughes, M S; Steele, T W

1994-01-01

282

Inositol methyl tranferase from a halophytic wild rice, Porteresia coarctata Roxb. (Tateoka): regulation of pinitol synthesis under abiotic stress.  

PubMed

Methylated inositol D-pinitol (3-O-methyl-D-chiro-inositol) accumulates in a number of plants naturally or in response to stress. Here, we present evidence for accumulation and salt-enhanced synthesis of pinitol in Porteresia coarctata, a halophytic wild rice, in contrast to its absence in domesticated rice. A cDNA for Porteresia coarctata inositol methyl transferase 1 (PcIMT1), coding for the inositol methyl transferase implicated in the synthesis of pinitol has been cloned from P. coarctata, bacterially overexpressed and shown to be functional in vitro. In silico analysis confirms the absence of an IMT1 homolog in Oryza genome, and PcIMT1 is identified as phylogenetically remotely related to the methyl transferase gene family in rice. Both transcript and proteomic analysis show the up-regulation of PcIMT1 expression following exposure to salinity. Coordinated expression of L-myo-inositol 1-phosphate synthase (PcINO1) gene along with PcIMT1 indicates that in P. coarctata, accumulation of pinitol via inositol is a stress-regulated pathway. The presence of pinitol synthesizing protein/gene in a wild halophytic rice is remarkable, although its exact role in salt tolerance of P. coarctata cannot be currently ascertained. The enhanced synthesis of pinitol in Porteresia under stress may be one of the adaptive features employed by the plant in addition to its known salt-exclusion mechanism. PMID:18643954

Sengupta, Sonali; Patra, Barunava; Ray, Sudipta; Majumder, Arun Lahiri

2008-10-01

283

Proteomic and physiological responses of the halophyte Cakile maritima to moderate salinity at the germinative and vegetative stages.  

PubMed

Responses of the halophyte Cakile maritima to moderate salinity were addressed at germination and vegetative stages by bringing together proteomics and eco-physiological approaches. 75 mM NaCl-salinity delayed significantly the germination process and decreased slightly the seed germination percentage compared to salt-free conditions. Monitoring the proteome profile between 0 h and 120 h after seed sowing revealed a delay in the degradation of seed storage proteins when germination took place under salinity, which may explain the slower germination rate observed. Of the sixty-seven proteins identified by mass spectrometry, several proteins involved in glycolysis, amino acid metabolism, photosynthesis, and protein folding showed significantly increased abundance during germination. This pattern was less pronounced under salinity. At the vegetative stage, 100mM NaCl-salinity stimulated significantly the plant growth, which was sustained by enhanced leaf expansion, water content, and photosynthetic activity. Comparative proteome analyses of leaf tissue revealed 44 proteins with different abundance changes, most of which being involved in energy metabolism. A specific set of proteins predominantly involved in photosynthesis and respiration showed significantly higher abundance in salt-treated plants. Altogether, combining proteomics with eco-physiological tools provides valuable information, which contributes to improve our understanding in the salt-response of this halophyte during its life cycle. PMID:22940175

Debez, Ahmed; Braun, Hans-Peter; Pich, Andreas; Taamalli, Wael; Koyro, Hans-Werner; Abdelly, Chedly; Huchzermeyer, Bernhard

2012-10-22

284

Effects of ‘Target’ Plant Species Body Size on Neighbourhood Species Richness and Composition in Old-Field Vegetation  

PubMed Central

Competition is generally regarded as an important force in organizing the structure of vegetation, and evidence from several experimental studies of species mixtures suggests that larger mature plant size elicits a competitive advantage. However, these findings are at odds with the fact that large and small plant species generally coexist, and relatively smaller species are more common in virtually all plant communities. Here, we use replicates of ten relatively large old-field plant species to explore the competitive impact of target individual size on their surrounding neighbourhoods compared to nearby neighbourhoods of the same size that are not centred by a large target individual. While target individuals of the largest of our test species, Centaurea jacea L., had a strong impact on neighbouring species, in general, target species size was a weak predictor of the number of other resident species growing within its immediate neighbourhood, as well as the number of resident species that were reproductive. Thus, the presence of a large competitor did not restrict the ability of neighbouring species to reproduce. Lastly, target species size did not have any impact on the species size structure of neighbouring species; i.e. they did not restrict smaller, supposedly poorer competitors, from growing and reproducing close by. Taken together, these results provide no support for a size-advantage in competition restricting local species richness or the ability of small species to coexist and successfully reproduce in the immediate neighbourhood of a large species. PMID:24349177

Schamp, Brandon S.; Aarssen, Lonnie W.; Wight, Stephanie

2013-01-01

285

Effects of 'target' plant species body size on neighbourhood species richness and composition in old-field vegetation.  

PubMed

Competition is generally regarded as an important force in organizing the structure of vegetation, and evidence from several experimental studies of species mixtures suggests that larger mature plant size elicits a competitive advantage. However, these findings are at odds with the fact that large and small plant species generally coexist, and relatively smaller species are more common in virtually all plant communities. Here, we use replicates of ten relatively large old-field plant species to explore the competitive impact of target individual size on their surrounding neighbourhoods compared to nearby neighbourhoods of the same size that are not centred by a large target individual. While target individuals of the largest of our test species, Centaurea jacea L., had a strong impact on neighbouring species, in general, target species size was a weak predictor of the number of other resident species growing within its immediate neighbourhood, as well as the number of resident species that were reproductive. Thus, the presence of a large competitor did not restrict the ability of neighbouring species to reproduce. Lastly, target species size did not have any impact on the species size structure of neighbouring species; i.e. they did not restrict smaller, supposedly poorer competitors, from growing and reproducing close by. Taken together, these results provide no support for a size-advantage in competition restricting local species richness or the ability of small species to coexist and successfully reproduce in the immediate neighbourhood of a large species. PMID:24349177

Schamp, Brandon S; Aarssen, Lonnie W; Wight, Stephanie

2013-01-01

286

REMOTE DETECTION OF INVASSIVE AND OPPORTUNISTIC PLANT SPECIES IN GREAT LAKES COASTAL WETLANDS  

EPA Science Inventory

Invasive and opportunistic plant species have been associated with wetland disturbance. Increases in the abundance of plant species such as common reed (Phragmites australis) in coastal Great Lakes wetlands are hypothesized to occur with shifts toward drier hydrologic regimes, fr...

287

REMOTE DETENTION OF INVASIVE AND OPPORTUNISTIC PLANT SPECIES IN GREAT LAKES COASTAL WETLANDS  

EPA Science Inventory

Invasive and opportunistic plant species have been associated with wetland disturbance. Increases in the abundance of plant species such as common reed (Phragmites australis) in coastal Great Lakes wetlands are hypothesized to occur with shifts toward drier hydrologic regimes, fr...

288

Negative Plant–Soil Feedback and Positive Species Interaction in a Herbaceous Plant Community  

Microsoft Academic Search

Increasing evidence shows that facilitative interaction and negative plant–soil feedback are driving factors of plant population\\u000a dynamics and community processes. We studied the intensity and the relative impact of negative feedback on clonal growth and\\u000a seed germination of Scirpus holoschoenus, a ‘ring’ forming sedge dominant in grazed grassland, and the consequences for species coexistence. The structure of aboveground\\u000a tussocks was

Giuliano Bonanomi; Max Rietkerk; Stefan C. Dekker; Stefano Mazzoleni

2005-01-01

289

[Psychoactive plant species--actual list of plants prohibited in Poland].  

PubMed

According to the Act on Counteracting Drug Addiction (20-th of March, 2009, Dz. U. Nr 63 poz. 520.) the list of federally prohibited plants in Poland was expanded to include 16 new species. Until that time the only illegal plant materials were cannabis, papaver, coca and most of their products. The actual list of herbal narcotics includes species which significantly influence on the central nervous system work but which are rarely described in the national literature. The plants usually come from distant places, where--among primeval cultures--are used for ritual purposes. In our civilization the plants are usually used experimentally, recreationally or to gain particular narcotic effects. The results of the consumption vary: they can be specific or less typical, imitate other substances intake, mental disorders or different pathological states. The plant active substances can interact with other medicaments, be toxic to internal organs, cause serious threat to health or even death. This article describes the sixteen plant species, which are now prohibited in Poland, their biochemical ingredients and their influence on the human organism. PMID:23885543

Simonienko, Katarzyna; Waszkiewicz, Napoleon; Szulc, Agata

2013-01-01

290

Invasive Plant Species: Inventory, Mapping, and Monitoring - A National Strategy  

USGS Publications Warehouse

America is under siege by invasive species of plants and animals, and by diseases. The current environmental, economic, and health-related costs of invasive species could exceed $138 billion per year-more than all other natural disasters combined. Notorious examples include West Nile virus, Dutch elm disease, chestnut blight, and purple loose- strife in the Northeast; kudzu, Brazilian peppertree, water hyacinth, nutria, and fire ants in the Southeast; zebra mussels, leafy spurge, and Asian long-horn beetles in the Midwest; salt cedar, Russian olive, and Africanized bees in the Southwest; yellow star thistle, European wild oats, oak wilt disease, Asian clams, and white pine blister rust in California; cheatgrass, various knapweeds, and thistles in the Great Basin; whirling disease of salmonids in the Northwest; hundreds of invasive species from microbes to mammals in Hawaii; and the brown tree snake in Guam. Thousands of species from other countries are introduced intentionally or accidentally into the United States each year. Based on past experience, 10-15 percent can be expected to establish free-living populations and about 1 percent can be expected to cause significant impacts to ecosystems, native species, economic productivity, and (or) human health.

Ludke, J. Larry; D'Erchia, Frank; Coffelt, Jan; Hanson, Leanne

2002-01-01

291

Spatially complex neighboring relationships among grassland plant species as an effective mechanism of defense against herbivory  

Microsoft Academic Search

Close spatial relationships between plant species are often important for defense against herbivory. The associational plant\\u000a defense may have important implications for plant community structure, species diversity, and species coexistence. An increasing\\u000a number of studies have focused on associational plant defense against herbivory at the scale of the individual plant and its\\u000a nearest neighbors. However, the average neighborhood effects between

Ling Wang; Deli Wang; Yuguang Bai; Yue Huang; Meng Fan; Jushan Liu; Yexing Li

2010-01-01

292

Appendix 15 Red and Blue-Listed Vertebrate and Vascular Plant Species The  

E-print Network

Appendix 15 Red and Blue-Listed Vertebrate and Vascular Plant Species The report that follows lists Mountain Management Plan Area. #12;Listed Vertebrate and Vascular Plant Species Occurring in the Cranbrook species of vertebrates and vascular plants that occur, or potentially occur, in the Cranbrook Forest

293

Ozone sensitivity of wild field layer plant species of northern Europe. A review  

Microsoft Academic Search

The increasing tropospheric ozone (O3) concentration constitutes a potential threat to nature. Plants are known to react to O3, but knowledge of the sensitivity and type of responses of different species and plant communities is widely lacking. This review focuses on the ecological effects of O3 on northern wild field layer plant species. Most of the 65 species examined thus

Ulla Timonen; Satu Huttunen; Sirkku Manninen

2004-01-01

294

Evaluating responses of four wetland plant species to different hydroperiods.  

PubMed

Previous work has estimated the hydroperiod requirements (saturation duration and frequency) of wetland plant communities by modeling their hydrologic regimes in natural (never drained) wetlands for a 40-yr period. This study tested the modeled predictions in a controlled greenhouse study using tree species representing three of the plant communities plus an additional species from another community. Bald cypress ( L. Rich.), sweet bay ( L.), pond pine ( Michx.), and swamp chestnut oak ( Nutt.) were grown under three hydroperiods (continuously ponded for 100 d, intermittently ponded for 14 d, and unsaturated) in loamy sand and sapric (organic) materials. Bald cypress (representing a Nonriverine Swamp Forest community) adapted well to 100 d of ponding by producing lateral roots near the soil surface and aerenchyma tissue in roots and stem. Sweet bay (Bay Forest community) also adapted well to 100 d of ponding by producing adventitious roots on the submerged portion of the stem. Pond pine (Pond Pine Woodland) and swamp chestnut oak (Nonriverine Wet Hardwood Forest) were intolerant of 100 d of ponded conditions. Seventy-five percent of the pond pine seedlings and 87% of the swamp chestnut oak seedlings died in the continuously ponded treatment level, whereas 100% of the bald cypress and 88% of the sweet bay seedlings survived. Results from this study suggest that modeled long-term hydroperiods of natural wetland plant communities can be used for restoration of these communities. PMID:25602673

Slusher, C E; Vepraskas, M J; Broome, S W

2014-03-01

295

Genetic control of invasive plants species using selfish genetic elements  

PubMed Central

Invasive plants cause substantial environmental damage and economic loss. Here, we explore the possibility that a selfish genetic element found in plants called cytoplasmic male sterility (CMS) could be exploited for weed control. CMS is caused by mutations in the mitochondrial genome that sterilize male reproductive organs. We developed an analytical model and a spatial simulation to assess the use of CMS alleles to manage weed populations. Specifically, we examined how fertility, selfing, pollen limitation and dispersal influenced extinction rate and time until extinction in populations where CMS arises. We found that the introduction of a CMS allele can cause rapid population extinction, but only under a restricted set of conditions. Both models suggest that the CMS strategy will be appropriate for species where pollen limitation is negligible, inbreeding depression is high and the fertility advantage of females over hermaphrodites is substantial. In general, spatial structure did not have a strong influence on the simulation outcome, although low pollen dispersal and intermediate levels of seed dispersal tended to reduce population extinction rates. Given these results, the introduction of CMS alleles into a population of invasive plants probably represents an effective control method for only a select number of species. PMID:25567898

Hodgins, Kathryn A; Rieseberg, Loren; Otto, Sarah P

2009-01-01

296

Hydroperiod regime controls the organization of plant species in wetlands  

PubMed Central

With urban, agricultural, and industrial needs growing throughout the past decades, wetland ecosystems have experienced profound changes. Most critically, the biodiversity of wetlands is intimately linked to its hydrologic dynamics, which in turn are being drastically altered by ongoing climate changes. Hydroperiod regimes, e.g., percentage of time a site is inundated, exert critical control in the creation of niches for different plant species in wetlands. However, the spatial signatures of the organization of plant species in wetlands and how the different drivers interact to yield such signatures are unknown. Focusing on Everglades National Park (ENP) in Florida, we show here that cluster sizes of each species follow a power law probability distribution and that such clusters have well-defined fractal characteristics. Moreover, we individuate and model those signatures via the interplay between global forcings arising from the hydroperiod regime and local controls exerted by neighboring vegetation. With power law clustering often associated with systems near critical transitions, our findings are highly relevant for the management of wetland ecosystems. In addition, our results show that changes in climate and land management have a quantifiable predictable impact on the type of vegetation and its spatial organization in wetlands. PMID:23150589

Foti, Romano; del Jesus, Manuel; Rinaldo, Andrea; Rodriguez-Iturbe, Ignacio

2012-01-01

297

Species-area relationships in Mediterranean-climate plant communities  

USGS Publications Warehouse

Aim: To determine the best-fit model of species-area relationships for Mediterranean-type plant communities and evaluate how community structure affects these species-area models. Location: Data were collected from California shrublands and woodlands and compared with literature reports for other Mediterranean-climate regions. Methods: The number of species was recorded from 1, 100 and 1000 m2 nested plots. Best fit to the power model or exponential model was determined by comparing adjusted r2 values from the least squares regression, pattern of residuals, homoscedasticity across scales, and semi-log slopes at 1-100 m2 and 100-1000 m2. Dominance-diversity curves were tested for fit to the lognormal model, MacArthur's broken stick model, and the geometric and harmonic series. Results: Early successional Western Australia and California shrublands represented the extremes and provide an interesting contrast as the exponential model was the best fit for the former, and the power model for the latter, despite similar total species richness. We hypothesize that structural differences in these communities account for the different species-area curves and are tied to patterns of dominance, equitability and life form distribution. Dominance-diversity relationships for Western Australian heathlands exhibited a close fit to MacArthur's broken stick model, indicating more equitable distribution of species. In contrast, Californian shrublands, both postfire and mature stands, were best fit by the geometric model indicating strong dominance and many minor subordinate species. These regions differ in life form distribution, with annuals being a major component of diversity in early successional Californian shrublands although they are largely lacking in mature stands. Both young and old Australian heathlands are dominated by perennials, and annuals are largely absent. Inherent in all of these ecosystems is cyclical disequilibrium caused by periodic fires. The potential for community reassembly is greater in Californian shrublands where only a quarter of the flora resprout, whereas three quarters resprout in Australian heathlands. Other Californian vegetation types sampled include coniferous forests, oak savannas and desert scrub, and demonstrate that different community structures may lead to a similar species-area relationship. Dominance-diversity relationships for coniferous forests closely follow a geometric model whereas associated oak savannas show a close fit to the lognormal model. However, for both communities, species-area curves fit a power model. The primary driver appears to be the presence of annuals. Desert scrub communities illustrate dramatic changes in both species diversity and dominance-diversity relationships in high and low rainfall years, because of the disappearance of annuals in drought years. Main conclusions: Species-area curves for immature shrublands in California and the majority of Mediterranean plant communities fit a power function model. Exceptions that fit the exponential model are not because of sampling error or scaling effects, rather structural differences in these communities provide plausible explanations. The exponential species-area model may arise in more than one way. In the highly diverse Australian heathlands it results from a rapid increase in species richness at small scales. In mature California shrublands it results from very depauperate richness at the community scale. In both instances the exponential model is tied to a preponderance of perennials and paucity of annuals. For communities fit by a power model, coefficients z and log c exhibit a number of significant correlations with other diversity parameters, suggesting that they have some predictive value in ecological communities.

Keeley, J.E.; Fotheringham, C.J.

2003-01-01

298

Plot shape effects on plant species diversity measurements  

USGS Publications Warehouse

Question: Do rectangular sample plots record more plant species than square plots as suggested by both empirical and theoretical studies? Location: Grasslands, shrublands and forests in the Mediterranean-climate region of California, USA. Methods: We compared three 0.1-ha sampling designs that differed in the shape and dispersion of 1-m2 and 100-m2 nested subplots. We duplicated an earlier study that compared the Whittaker sample design, which had square clustered subplots, with the modified Whittaker design, which had dispersed rectangular subplots. To sort out effects of dispersion from shape we used a third design that overlaid square subplots on the modified Whittaker design. Also, using data from published studies we extracted species richness values for 400-m2 subplots that were either square or 1:4 rectangles partially overlaid on each other from desert scrub in high and low rainfall years, chaparral, sage scrub, oak savanna and coniferous forests with and without fire. Results: We found that earlier empirical reports of more than 30% greater richness with rectangles were due to the confusion of shape effects with spatial effects, coupled with the use of cumulative number of species as the metric for comparison. Average species richness was not significantly different between square and 1:4 rectangular sample plots at either 1-or 100-m2. Pairwise comparisons showed no significant difference between square and rectangular samples in all but one vegetation type, and that one exhibited significantly greater richness with squares. Our three intensive study sites appear to exhibit some level of self-similarity at the scale of 400 m2, but, contrary to theoretical expectations, we could not detect plot shape effects on species richness at this scale. Conclusions: At the 0.1-ha scale or lower there is no evidence that plot shape has predictable effects on number of species recorded from sample plots. We hypothesize that for the mediterranean-climate vegetation types studied here, the primary reason that 1:4 rectangles do not sample greater species richness than squares is because species turnover varies along complex environmental gradients that are both parallel and perpendicular to the long axis of rectangular plots. Reports in the literature of much greater species richness recorded for highly elongated rectangular strips than for squares of the same area are not likely to be fair comparisons because of the dramatically different periphery/area ratio, which includes a much greater proportion of species that are using both above and below-ground niche space outside the sample area. ?? IAVS; Opulus Press Uppsala.

Keeley, J.E.; Fotheringham, C.J.

2005-01-01

299

Visiting insect diversity and visitation rates for seven globally-imperiled plant species in  

E-print Network

Visiting insect diversity and visitation rates for seven globally-imperiled plant species of Natural Resources, Colorado State University Ft. Collins, Colorado prepared for Native Plant Conservation......................................................................................................................................... 20 Rare plant inventory and assessments

300

Biodiversity, exotic plant species, and herbivory: The good, the bad, and the ungulate  

Microsoft Academic Search

Invasion of natural ecosystems by exotic plant species is a major threat to biodiversity. Disturbance to native plant communities, whether natural or management induced, is a primary factor contributing to successful invasion by exotic plant species. Herbivory by both wild and domestic ungulates exerts considerable impact on structure and composition of native plant communities. Intensive herbivory by ungulates can enhance

Marty Vavra; Catherine G. Parks; Michael J. Wisdom

2007-01-01

301

Covariation and composition of arthropod species across plant genotypes of evening primrose, Oenothera biennis  

Microsoft Academic Search

Genetic variation in plants has broad implications for both the ecology and evolution of species interactions. We addressed how a diverse community of arthropod species covary in abundance among plant genotypes of a native herbaceous plant (Oenothera biennis ), and if these effects scale-up to shape the composition, diversity, and total abundance of arthropods over the entire lifetime of plants

Marc T. J. Johnson; Anurag A. Agrawal

2007-01-01

302

Plant species richness drives the density and diversity of Collembola in temperate grassland  

Microsoft Academic Search

Declining biodiversity is one of the most important aspects of anthropogenic global change phenomena, but the implications of plant species loss for soil decomposers are little understood. We used the experimental grassland community of the Jena Experiment to assess the response of density and diversity of Collembola to varying plant species richness, plant functional group richness and plant functional group

Alexander C. W. Sabais; Stefan Scheu; Nico Eisenhauer

2011-01-01

303

Metabolomics Unravel Contrasting Effects of Biodiversity on the Performance of Individual Plant Species  

Microsoft Academic Search

In spite of evidence for positive diversity-productivity relationships increasing plant diversity has highly variable effects on the performance of individual plant species, but the mechanisms behind these differential responses are far from being understood. To gain deeper insights into the physiological responses of individual plant species to increasing plant diversity we performed systematic untargeted metabolite profiling on a number of

Christian Scherling; Christiane Roscher; Patrick Giavalisco; Ernst-Detlef Schulze; Wolfram Weckwerth; Jerome Chave

2010-01-01

304

Soil vs. canopy seed storage and plant species coexistence in species-rich Australian shrublands.  

PubMed

The fire-prone shrublands of southwestern Australia are renowned for their high plant species diversity and prominence of canopy seed storage (serotiny). We compared species richness, abundance, and life history attributes for soil and canopy seed banks in relation to extant vegetation among four sites with different substrate conditions and high species turnover (50-80%) to identify whether this unusual community-level organization of seed storage might contribute to maintenance of high species richness. Soil seed bank (SSB) densities were low to moderate (233-1435 seeds/m2) compared with densities for other Mediterranean-type vegetation and were lowest for sites with highest canopy seed bank (CSB) species richness and lowest nutrient availability, but not richness or abundance of resprouters. Annuals were infrequent in the lowest nutrient sites, but there was no evidence that small SSB size was due to low seed inputs or a trade-off between seed production/storage and seed size in response to low nutrient availability. Sorensen's similarity between SSB and extant vegetation was 26-43% but increased to 54-57% when the CSB was included, representing levels higher than reported for most other ecosystems. Resprouting species were well represented in both the SSB and CSB, and there was no evidence for lower seed production in resprouters than in non-sprouters overall. The SSB and CSB held no species in common and were characterized by markedly different seed dispersal attributes, with winged or small seeds in the CSB and seeds dispersed by ants, birds, and wind (though none with wings) in the SSB. There was no evidence of spatial differentiation in the distribution of seeds of SSB species between vegetated and open microsites that might facilitate species coexistence, but most woody non-sprouters showed aggregation at scales of 1-2 m, implying limited seed dispersal. High similarity between overall seed bank (SSB + CSB) and extant species composition, high number of resprouting species, and seed dispersal processes before (SSB) and after fire (CSB) leading to differential spatial aggregation of post-fire recruits from the two seed bank types may buffer species composition against rapid change and provide a mechanism for maintaining species coexistence at the local scale. PMID:17918407

Enright, N J; Mosner, E; Miller, B P; Johnson, N; Lamont, Byron B

2007-09-01

305

ELEVATED CO2 AND PLANT PLANT SPECIES RICHNESS IMPACT ARBUSCULAR MYCORRHIZAL FUNGAL SPORE COMMUNITIES  

Technology Transfer Automated Retrieval System (TEKTRAN)

We enumerated arbuscular mycorrhizal fungal spore communities for three years as part of a long-term Free-Air CO2 Enrichment experiment (BioCON) at Cedar Creek, Minnesota, USA. Complete factorial combinations of two levels of CO2 and N, and sixteen perennial plant species grown in monoculture and si...

306

Stakeholders' perceptions of the impacts of invasive exotic plant species in the Mediterranean region  

E-print Network

and use of certain exotic species. For effective control of invasive exotic species, management approaches sustainability. To substantiate an argument to control invasive exotic plant species, a quantificationStakeholders' perceptions of the impacts of invasive exotic plant species in the Mediterranean

Boudouresque, Charles F.

307

Cloning and characterization of Na+/H+ antiporter (LfNHX1) gene from a halophyte grass Leptochloa fusca for drought and salt tolerance.  

PubMed

Abiotic stresses such as salinity and drought have adverse effects on plants. In the present study, a Na(+)/H(+) antiporter gene homologue (LfNHX1) has been cloned from a local halophyte grass (Leptochloa fusca). The LfNHX1 cDNA contains an open reading frame of 1,623 bp that encodes a polypeptide chain of 540 amino acid residues. LfNHX1 protein sequence showed high similarity with NHX1 homologs reported from other halophyte plants. Amino acid and nucleotide sequence similarity, protein topology modeling and the presence of conserved functional domains in the LfNHX1 protein sequence classified it as a vacuolar NHX1 homolog. The overexpression of LfNHX1 gene under CaMV35S promoter conferred salt and drought tolerance in tobacco plants. Under drought stress, transgenic plants showed higher relative water contents, photosynthetic rate, stomatal conductance and membrane stability index as compared to wild type plants. More negative value of leaf osmotic potential was also observed in transgenic plants when compared with wild type control plants. Transgenic plants showed better germination and root growth at 2 mg L(-1) Basta herbicide and three levels (100, 200 and 250 mM) of sodium chloride. These results showed that LfNHX1 is a potential candidate gene for enhancing drought and salt tolerance in crops. PMID:24420850

Rauf, Muhammad; Shahzad, Khurram; Ali, Rashid; Ahmad, Moddassir; Habib, Imran; Mansoor, Shahid; Berkowitz, Gerald A; Saeed, Nasir A

2014-03-01

308

78 FR 58938 - Endangered and Threatened Wildlife and Plants; Determination of Endangered Species Status for the...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Wildlife and Plants; Determination of Endangered Species Status for the Grotto Sculpin (Cottus...Fish and Wildlife Service, determine endangered species status under the Endangered Species Act of 1973, as amended, for the...

2013-09-25

309

[Magnetic liquid influence upon some plant species of pharmaceutical interest].  

PubMed

It was accomplished a study on the influence of a petroleum magnetic liquid upon two plant species of pharmaceutical interest: Papaver somniferum L. and Chelidonium majus L. Experimental observation aimed: callus accumulation, seed germination, mitotic index and fluorescence of the photosynthesis pigments. The plant samples were taken from in vitro cultures obtained from different explant types while the magnetic liquid was added in the culture media in low concentrations (ml/l). The germination test showed a positive influence of the magnetic liquid, the cell division test revealed an increased mitotic index, callus accumulation rate is enhanced while the fluorescence spectra showed maxima shift for the samples in comparison to the controls. PMID:12092195

Pavel, A; Vlahovici, A; Trifan, M; B?ra, I I; Creang?, D

2001-01-01

310

Does resource availability, resource heterogeneity or species turnover mediate changes in plant species richness in grazed grasslands?  

PubMed

Grazing by large ungulates often increases plant species richness in grasslands of moderate to high productivity. In a mesic North American grassland with and without the presence of bison ( Bos bison), a native ungulate grazer, three non-exclusive hypotheses for increased plant species richness in grazed grasslands were evaluated: (1) bison grazing enhances levels of resource (light and N) availability, enabling species that depend on higher resource availability to co-occur; (2) spatial heterogeneity in resource availability is enhanced by bison, enabling coexistence of a greater number of plant species; (3) increased species turnover (i.e. increased species colonization and establishment) in grazed grassland is associated with enhanced plant species richness. We measured availability and spatial heterogeneity in light, water and N, and calculated species turnover from long-term data in grazed and ungrazed sites in a North American tallgrass prairie. Both regression and path analyses were performed to evaluate the potential of the three hypothesized mechanisms to explain observed patterns of plant species richness under field conditions. Experimental grazing by bison increased plant species richness by 25% over an 8-year period. Neither heterogeneity nor absolute levels of soil water or available N were related to patterns of species richness in grazed and ungrazed sites. However, high spatial heterogeneity in light and higher rates of species turnover were both strongly related to increases in plant species richness in grazed areas. This suggests that creation of a mosaic of patches with high and low biomass (the primary determinant of light availability in mesic grasslands) and promotion of a dynamic species pool are the most important mechanisms by which grazers affect species richness in high productivity grasslands. PMID:12955488

Bakker, C; Blair, J M; Knapp, A K

2003-11-01

311

Does resource availability, resource heterogeneity or species turnover mediate changes in plant species richness in grazed grasslands?  

Microsoft Academic Search

Grazing by large ungulates often increases plant species richness in grasslands of moderate to high productivity. In a mesic North American grassland with and without the presence of bison ( Bos bison), a native ungulate grazer, three non-exclusive hypotheses for increased plant species richness in grazed grasslands were evaluated: (1) bison grazing enhances levels of resource (light and N) availability,

C. Bakker; J. M. Blair; A. K. Knapp

2003-01-01

312

Cross-species translocation of mRNA from host plants into the parasitic plant dodder.  

PubMed

An intriguing new paradigm in plant biology is that systemically mobile mRNAs play a role in coordinating development. In this process, specific mRNAs are loaded into the phloem transport stream for translocation to distant tissues, where they may impact on developmental processes. However, despite its potential significance for plant growth regulation, mRNA trafficking remains poorly understood and challenging to study. Here, we show that phloem-mobile mRNAs can also traffic between widely divergent species from a host to the plant parasite lespedeza dodder (Cuscuta pentagona Engelm.). Reverse transcription-polymerase chain reaction and microarray analysis were used to detect specific tomato (Lycopersicon esculentum Mill.) transcripts in dodder grown on tomato that were not present in control dodder grown on other host species. Foreign transcripts included LeGAI, which has previously been shown to be translocated in the phloem, as well as nine other transcripts not reported to be mobile. Dodders are parasitic plants that obtain resources by drawing from the phloem of a host plant and have joint plasmodesmata with host cortical cells. Although viruses are known to move between dodder and its hosts, translocation of endogenous plant mRNA has not been reported. These results point to a potentially new level of interspecies communication, and raise questions about the ability of parasites to recognize, use, and respond to transcripts acquired from their hosts. PMID:17189329

Roney, Jeannine K; Khatibi, Piyum A; Westwood, James H

2007-02-01

313

Critical Reviews in Plant Sciences, 18(2):227255 (1999) Copyright 1999, CRC Press LLC --Files may be downloaded for personal use only. Reproduc-  

E-print Network

tested as vegetable, forage, and oilseed crops in agronomic field trials. The most productive species halophyte, Sali- cornia bigelovii, yields 2 t/ha of seed containing 28% oil and 31% protein, similar. Halophyte forage and seed products can replace conventional ingredients in animal feeding systems, with some

Blumwald, Eduardo

1999-01-01

314

Spatial variation of plant communities and shoot Cu concentrations of plant species at a timber treatment site  

Microsoft Academic Search

Plant species, spatial variability in plant diversity and vegetation cover were recorded at a French timber treatment site\\u000a with Cu-contaminated soils (65–2600 mg\\/kg). Shoot biomass, shoot Cu concentration and accumulation were determined for each\\u000a plant species found on 168 quadrats with increasing total Cu in soil and soil solution. A total of 91 species occurred on\\u000a the site including four considered

Clémence M. Bes; Michel Mench; Maurice Aulen; Hélène Gaste; Julie Taberly

2010-01-01

315

Arthropod assemblages on native and nonnative plant species of a coastal reserve in California.  

PubMed

Biological invasions by nonnative plant species are a widespread phenomenon. Many studies have shown strong ecological impacts of plant invasions on native plant communities and ecosystem processes. Far fewer studies have examined effects on associated animal communities. From the perspective of a reserve's land management, I addressed the question of whether arthropod assemblages on two nonnative plant species of concern were impoverished compared with those assemblages associated with two predominant native plant species of that reserve. If the nonnative plant species, Conium maculatum L., and Phalaris aquatica L., supported highly depauperate arthropod assemblages compared with the native plant species, Baccharis pilularis De Candolle and Leymus triticoides (Buckley) Pilger, this finding would provide additional support for prioritizing removal of nonnatives and restoration of natives. I assessed invertebrate assemblages at the taxonomic levels of arthropod orders, Coleoptera families, and Formicidae species, using univariate analyses to examine community attributes (richness and abundance) and multivariate techniques to assess arthropod assemblage community composition differences among plant species. Arthropod richness estimates by taxonomic level between native and nonnative vegetation showed varying results. Overall, arthropod richness of the selected nonnative plants, examined at higher taxonomic resolution, was not necessarily less diverse than two of common native plants found on the reserve, although differences were found among plant species. Impacts of certain nonnative plant species on arthropod assemblages may be more difficult to elucidate than those impacts shown on native plants and ecosystem processes. PMID:20550788

Fork, Susanne K

2010-06-01

316

The predominance of inorganic arsenic species in plants from Yellowknife, Northwest Territories, Canada  

SciTech Connect

Elevated levels of arsenic in Yellowknife, NWT, Canada, from historic and recent gold mine operations, are of increasing concern to Yellowknife residents. The study of arsenic in Yellowknife plants is a part of ongoing bioavailability and food chain research. A variety of plants from Yellowknife were analyzed for total arsenic and water soluble arsenic species. The plants included vascular plants and bryophytes (mosses). Total amounts of arsenic were greatest in mosses and varied greatly within specimens of the same plant species from different locations. Mostly inorganic arsenic species were extracted from plants using methanol/water (1:1). This result is very important from a toxicological point of view, since inorganic species are relatively toxic arsenic species. Small amounts of methylated arsenic species, as well as arsenosugars, were present in some plants. On average, greater than 50% of arsenic in these plants was not extracted; the chemical and toxicological characteristics of this fraction remain a topic for further study.

Koch, I.; Wang, L.; Ollson, C.A.; Cullen, W.R.; Reimer, K.J.

2000-01-01

317

Plant Functional Diversity and Species Diversity in the Mongolian Steppe  

PubMed Central

Background The Mongolian steppe is one of the most important grasslands in the world but suffers from aridization and damage from anthropogenic activities. Understanding structure and function of this community is important for the ecological conservation, but has seldom been investigated. Methodology/Principal Findings In this study, a total of 324 quadrats located on the three main types of Mongolian steppes were surveyed. Early-season perennial forbs (37% of total importance value), late-season annual forbs (33%) and late-season perennial forbs (44%) were dominant in meadow, typical and desert steppes, respectively. Species richness, diversity and plant functional type (PFT) richness decreased from the meadow, via typical to desert steppes, but evenness increased; PFT diversity in the desert and meadow steppes was higher than that in typical steppe. However, above-ground net primary productivity (ANPP) was far lower in desert steppe than in the other two steppes. In addition, the slope of the relationship between species richness and PFT richness increased from the meadow, via typical to desert steppes. Similarly, with an increase in species diversity, PFT diversity increased more quickly in both the desert and typical steppes than that in meadow steppe. Random resampling suggested that this coordination was partly due to a sampling effect of diversity. Conclusions/Significance These results indicate that desert steppe should be strictly protected because of its limited functional redundancy, which its ecological functioning is sensitive to species loss. In contrast, despite high potential forage production shared by the meadow and typical steppes, management of these two types of steppes should be different: meadow steppe should be preserved due to its higher conservation value characterized by more species redundancy and higher spatial heterogeneity, while typical steppe could be utilized moderately because its dominant grass genus Stipa is resistant to herbivory and drought. PMID:24116233

Liu, Guofang; Xie, Xiufang; Ye, Duo; Ye, Xuehua; Tuvshintogtokh, Indree; Mandakh, Bayart; Huang, Zhenying; Dong, Ming

2013-01-01

318

Imperfect replacement of native species by non-native species as pollinators of endemic Hawaiian plants.  

PubMed

Native plant species that have lost their mutualist partners may require non-native pollinators or seed dispersers to maintain reproduction. When natives are highly specialized, however, it appears doubtful that introduced generalists will partner effectively with them. We used visitation observations and pollination treatments (experimental manipulations of pollen transfer) to examine relationships between the introduced, generalist Japanese White-eye (Zosterops japonicus) and 3 endemic Hawaiian plant species (Clermontia parviflora, C. montis-loa, and C. hawaiiensis). These plants are characterized by curved, tubular flowers, apparently adapted for pollination by curve-billed Hawaiian honeycreepers. Z. japonicus were responsible for over 80% of visits to flowers of the small-flowered C. parviflora and the midsize-flowered C. montis-loa. Z. japonicus-visited flowers set significantly more seed than did bagged flowers. Z. japonicus also demonstrated the potential to act as an occasional Clermontia seed disperser, although ground-based frugivory by non-native mammals likely dominates seed dispersal. The large-flowered C. hawaiiensis received no visitation by any birds during observations. Unmanipulated and bagged C. hawaiiensis flowers set similar numbers of seeds. Direct examination of Z. japonicus and Clermontia morphologies suggests a mismatch between Z. japonicus bill morphology and C. hawaiiensis flower morphology. In combination, our results suggest that Z. japonicus has established an effective pollination relationship with C. parviflora and C. montis-loa and that the large flowers of C. hawaiiensis preclude effective visitation by Z. japonicus. PMID:24372761

Aslan, Clare E; Zavaleta, Erika S; Tershy, Bernie; Croll, Don; Robichaux, Robert H

2014-04-01

319

Novel chemistry of invasive plants: exotic species have more unique metabolomic profiles than native congeners  

PubMed Central

It is often assumed that exotic plants can become invasive when they possess novel secondary chemistry compared with native plants in the introduced range. Using untargeted metabolomic fingerprinting, we compared a broad range of metabolites of six successful exotic plant species and their native congeners of the family Asteraceae. Our results showed that plant chemistry is highly species-specific and diverse among both exotic and native species. Nonetheless, the exotic species had on average a higher total number of metabolites and more species-unique metabolites compared with their native congeners. Herbivory led to an overall increase in metabolites in all plant species. Generalist herbivore performance was lower on most of the exotic species compared with the native species. We conclude that high chemical diversity and large phytochemical uniqueness of the exotic species could be indicative of biological invasion potential. PMID:25077026

Macel, Mirka; de Vos, Ric C H; Jansen, Jeroen J; van der Putten, Wim H; van Dam, Nicole M

2014-01-01

320

Historic land use influences contemporary establishment of invasive plant species.  

PubMed

The legacy of agricultural land use can have widespread and persistent effects on contemporary landscapes. Although agriculture can lead to persistent changes in soil characteristics and plant communities, it remains unclear whether historic agricultural land use can alter the likelihood of contemporary biological invasions. To understand how agricultural land-use history might interact with well-known drivers of invasion, we conducted factorial manipulations of soil disturbance and resource additions within non-agricultural remnant sites and post-agricultural sites invaded by two non-native Lespedeza species. Our results reveal that variation in invader success can depend on the interplay of historic land use and contemporary processes: for both Lespedeza species, establishment was greater in remnant sites, but soil disturbance enhanced establishment irrespective of land-use history, demonstrating that contemporary processes can help to overcome legacy constraints on invader success. In contrast, additions of resources known to facilitate seedling recruitment (N and water) reduced invader establishment in post-agricultural but not in remnant sites, providing evidence that interactions between historic and contemporary processes can also limit invader success. Our findings thus illustrate that a consideration of historic land use may help to clarify the often contingent responses of invasive plants to known determinants of invasibility. Moreover, in finding significantly greater soil compaction at post-agricultural sites, our study provides a putative mechanism for historic land-use effects on contemporary invasive plant establishment. Our work suggests that an understanding of invasion dynamics requires knowledge of anthropogenic events that often occur decades before the introduction of invasive propagules. PMID:23277213

Mattingly, W Brett; Orrock, John L

2013-08-01

321

Positive Effects of Plant Genotypic and Species Diversity on Anti-Herbivore Defenses in a Tropical Tree Species  

PubMed Central

Despite increasing evidence that plant intra- and inter-specific diversity increases primary productivity, and that such effect may in turn cascade up to influence herbivores, there is little information about plant diversity effects on plant anti-herbivore defenses, the relative importance of different sources of plant diversity, and the mechanisms for such effects. For example, increased plant growth at high diversity may lead to reduced investment in defenses via growth-defense trade-offs. Alternatively, positive effects of plant diversity on plant growth may lead to increased herbivore abundance which in turn leads to a greater investment in plant defenses. The magnitude of trait variation underlying diversity effects is usually greater among species than among genotypes within a given species, so plant species diversity effects on resource use by producers as well as on higher trophic levels should be stronger than genotypic diversity effects. Here we compared the relative importance of plant genotypic and species diversity on anti-herbivore defenses and whether such effects are mediated indirectly via diversity effects on plant growth and/or herbivore damage. To this end, we performed a large-scale field experiment where we manipulated genotypic diversity of big-leaf mahogany (Swietenia macrophylla) and tree species diversity, and measured effects on mahogany growth, damage by the stem-boring specialist caterpillar Hypsipyla grandella, and defensive traits (polyphenolics and condensed tannins in stem and leaves). We found that both forms of plant diversity had positive effects on stem (but not leaf) defenses. However, neither source of diversity influenced mahogany growth, and diversity effects on defenses were not mediated by either growth-defense trade-offs or changes in stem-borer damage. Although the mechanism(s) of diversity effects on plant defenses are yet to be determined, our study is one of the few to test for and show producer diversity effects on plant chemical defenses. PMID:25141305

Moreira, Xoaquín; Abdala-Roberts, Luis; Parra-Tabla, Víctor; Mooney, Kailen A.

2014-01-01

322

Positive effects of plant genotypic and species diversity on anti-herbivore defenses in a tropical tree species.  

PubMed

Despite increasing evidence that plant intra- and inter-specific diversity increases primary productivity, and that such effect may in turn cascade up to influence herbivores, there is little information about plant diversity effects on plant anti-herbivore defenses, the relative importance of different sources of plant diversity, and the mechanisms for such effects. For example, increased plant growth at high diversity may lead to reduced investment in defenses via growth-defense trade-offs. Alternatively, positive effects of plant diversity on plant growth may lead to increased herbivore abundance which in turn leads to a greater investment in plant defenses. The magnitude of trait variation underlying diversity effects is usually greater among species than among genotypes within a given species, so plant species diversity effects on resource use by producers as well as on higher trophic levels should be stronger than genotypic diversity effects. Here we compared the relative importance of plant genotypic and species diversity on anti-herbivore defenses and whether such effects are mediated indirectly via diversity effects on plant growth and/or herbivore damage. To this end, we performed a large-scale field experiment where we manipulated genotypic diversity of big-leaf mahogany (Swietenia macrophylla) and tree species diversity, and measured effects on mahogany growth, damage by the stem-boring specialist caterpillar Hypsipyla grandella, and defensive traits (polyphenolics and condensed tannins in stem and leaves). We found that both forms of plant diversity had positive effects on stem (but not leaf) defenses. However, neither source of diversity influenced mahogany growth, and diversity effects on defenses were not mediated by either growth-defense trade-offs or changes in stem-borer damage. Although the mechanism(s) of diversity effects on plant defenses are yet to be determined, our study is one of the few to test for and show producer diversity effects on plant chemical defenses. PMID:25141305

Moreira, Xoaquín; Abdala-Roberts, Luis; Parra-Tabla, Víctor; Mooney, Kailen A

2014-01-01

323

Species specific plant-soil interactions influence plant distribution on serpentine soils  

Microsoft Academic Search

Where serpentine soils exist, variation in soil properties affects plant species distribution at both coarse and fine spatial\\u000a scales. The New Idria (California, USA) serpentine mass has barren areas, supporting only sparse shrub and tree islands, adjacent\\u000a to areas of densely-vegetated serpentine chaparral. To identify factors limiting growth on barren relative to vegetated serpentine\\u000a soils, we analyzed soils from barren,

Brynne E. Lazarus; James H. Richards; Victor P. Claassen; Ryan E. O’Dell; Molly A. Ferrell

2011-01-01

324

The evolution of cultivated plant species: classical plant breeding versus genetic engineering  

Microsoft Academic Search

Agriculture is the most intensive form of environmental exploitation performed by mankind. It involves replacing the natural\\u000a ecosystem with an artificial plant community comprising one or more crop species, and weeds can invade the cleared land. Initially,\\u000a the adoption of agriculture did not necessarily imply an improvement in standard of living (there is, in fact, evidence to\\u000a the contrary), but

Hakan Ulukan

2009-01-01

325

Comparison of relative antioxidant activities of British medicinal plant species in vitro  

Microsoft Academic Search

We have determined the relative levels of endogenous antioxidant activity in a range of British medicinal plant species (representative of a variety of plant families, selected on the basis of their widespread use in traditional herbal medicine), via competitive scavenging of the ABTS+ or O2? radicals in vitro. A number of plant species with appreciable levels (i.e. greater than or

David Mantle; Fadel Eddeb; Anne T. Pickering

2000-01-01

326

Screening Plant Species for Growth on Weathered, Petroleum Hydrocarbon-Contaminated Sediments  

Microsoft Academic Search

Rapid and cost-effective techniques are needed to select plant species and genotypes for use in phytoremediation, vegetative capping, or revegetation at hazardous waste sites. A greenhouse screening procedure to aid the selection of plant materials would help increase success and decrease the cost. Twenty-nine vascular plant species were compared for growth in weathered sediments contaminated with petroleum hydrocarbons. An uncontaminated

Peter A. Kulakow; A. P. Schwab; M. K. Banks

2000-01-01

327

Species-driven changes in nitrogen cycling can provide a mechanism for plant invasions  

E-print Network

Species-driven changes in nitrogen cycling can provide a mechanism for plant invasions Ramesh than competing established spe- cies. In many terrestrial ecosystems nitrogen limits plant growth, and is a key factor determining productivity and the outcome of competition among species. Plant nitrogen use

Minnesota, University of

328

OIKOS 100: 362372, 2003 Mycorrhizal species identity affects plant community structure and  

E-print Network

OIKOS 100: 362­372, 2003 Mycorrhizal species identity affects plant community structure. Mycorrhizal species identity affects plant community structure and invasion: a microcosm study. ­ Oikos 100: 362­372. Previous studies have shown that arbuscular mycorrhizal fungi (AMF) can mediate plant

Bruns, Tom

329

Plant species richness of afforestations with different former use and habitat continuity  

Microsoft Academic Search

In northeastern Germany, the presence of 148 vascular plant species in 155 woodlands, which have been planted during the last 200 years, was observed. Woodlands existing continuously from the 19th century were called old woodlands whereas those from the 20th century were called recent woodland. Five species were significantly associated with old woodlands whereas six species were more often found

Monika Wulf

2004-01-01

330

Riparian zones as havens for exotic plant species in the central grasslands  

Microsoft Academic Search

In the Central Grasslands of the United States, we hypothesized that riparian zones high in soil fertility would contain more exotic plant species than upland areas of low soil fertility. Our alternate hypothesis was that riparian zones high in native plant species richness and cover would monopolize available resources and resist invasion by exotic species. We gathered nested-scale vegetation data

Thomas J. Stohlgren; Kelly A. Bull; Yuka Otsuki; Cynthia A. Villa; Michelle Lee

1998-01-01

331

Distribution of plants in a California serpentine grassland: are rocky hummocks spatial refuges for native species?  

E-print Network

Distribution of plants in a California serpentine grassland: are rocky hummocks spatial refuges for native species. In the heavily invaded serpentine grasslands of central California, many native species tested whether native plant species were restricted to hummocks within a serpentine grassland

332

Species-specific Effects of Vascular Plants on Carbon Turnover and Methane Emissions from Wetlands  

Microsoft Academic Search

Species composition affects the carbon turnover and the formation and emission of the greenhouse gas methane (CH4) in wetlands. Here we investigate the individual effects of vascular plant species on the carbon cycling in a wetland ecosystem. We used a novel combination of laboratory methods and controlled environment facilities and studied three different vascular plant species (Eriophorum vaginatum, Carex rostrata

Lena Ström; Mikhail Mastepanov; Torben R. Christensen

2005-01-01

333

Effects of Earthworm Invasion on Plant Species Richness in Northern Hardwood Forests  

E-print Network

Effects of Earthworm Invasion on Plant Species Richness in Northern Hardwood Forests ANDREW R of non-native earthworms (Lumbricus spp.) into a small number of intensively studied stands of northern forests, which plant species are most vulnerable, or with which earthworm species such changes

Minnesota, University of

334

Productivity is a poor predictor of plant species richness  

USGS Publications Warehouse

For more than 30 years, the relationship between net primary productivity and species richness has generated intense debate in ecology about the processes regulating local diversity. The original view, which is still widely accepted, holds that the relationship is hump-shaped, with richness first rising and then declining with increasing productivity. Although recent meta-analyses questioned the generality of hump-shaped patterns, these syntheses have been criticized for failing to account for methodological differences among studies. We addressed such concerns by conducting standardized sampling in 48 herbaceous-dominated plant communities on five continents. We found no clear relationship between productivity and fine-scale (meters-2) richness within sites, within regions, or across the globe. Ecologists should focus on fresh, mechanistic approaches to understanding the multivariate links between productivity an

Adler, Peter B.; Seabloom, Eric W.; Borer, Elizabeth T.; Hillebrand, Helmut; Hautier, Yann; Hector, Andy; Harpole, W. Stanley; O'Halloran, Lydia R.; Grace, James B.; Anderson, T. Michael; Bakker, Jonathan D.; Biederman, Lori A.; Brown, Cynthia S.; Buckley, Yvonne M.; Calabrese, Laura B.; Chu, Cheng-Jin; Cleland, Elsa E.; Collins, Scott L.; Cottingham, Kathryn L.; Crawley, Michael J.; Damschen, Ellen I.; Davies, Kendi F.; DeCrappeo, Nicole M.; Fay, Philip A.; Firn, Jennifer; Frater, Paul; Gasarch, Eve I.; Gruner, Daneil S.; Hagenah, Nicole; Lambers, Janneke Hille Ris; Humphries, Hope; Jin, Virginia L.; Kay, Adam D.; Kirkman, Kevin P.; Klein, Julia A.; Knops, Johannes M.H.; La Pierre, Kimberly J.; Lambrinos, John G.; Li, Wei; MacDougall, Andrew S.; McCulley, Rebecca L.; Melbourne, Brett A.; Mitchell, Charles E.; Moore, Joslin L.; Morgan, John W.; Mortensen, Brent; Orrock, John L.; Prober, Suzanne M.; Pyke, David A.; Risch, Anita C.; Schuetz, Martin; Smith, Melinda D.; Stevens, Carly J.; Sullivan, Lauren L.; Wang, Gang; Wragg, Peter D.; Wright, Justin P.; Yang, Louie H.

2011-01-01

335

Productivity Is a Poor Predictor of Plant Species Richness.  

SciTech Connect

For more than 30 years, the relationship between net primary productivity and species richness has generated intense debate in ecology about the processes regulating local diversity. The original view, which is still widely accepted, holds that the relationship is hump-shaped, with richness first rising and then declining with increasing productivity. Although recent meta-analyses questioned the generality of hump-shaped patterns, these syntheses have been criticized for failing to account for methodological differences among studies. We addressed such concerns by conducting standardized sampling in 48 herbaceous-dominated plant communities on five continents. We found no clear relationship between productivity and fine-scale (meters-2) richness within sites, within regions, or across the globe. Ecologists should focus on fresh, mechanistic approaches to understanding the multivariate links between productivity and richness.

Peter B. Adler; et al.

2011-09-22

336

Changes in Semi-Arid Plant Species Associations along a Livestock Grazing Gradient  

PubMed Central

In semi-arid ecosystems, vegetation is heterogeneously distributed, with plant species often associating in patches. These associations between species are not constant, but depend on the particular response of each species to environmental factors. Here, we investigated how plant species associations change in response to livestock grazing in a semi-arid ecosystem, Cabo de Gata-Níjar Natural Park in South East Spain. We established linear point-intercept transects at four sites with different grazing intensity, and recorded all species at each point. We investigated plant associations by comparing the number of times that each pair of species occurred at the same spatial point (co-occurrences), with the expected number of times based on species abundances. We also assessed associations for each shrub and grass species by considering all their pairs of associations and for the whole plant community by considering all pairs of associations on each site. At all sites, the plant community had a negative pattern of association, with fewer co-occurrences than expected. Negative association in the plant community increased at maximum grazing intensity. Most species associated as expected, particularly grass species, and positive associations were most important at intermediate grazing intensities. No species changed its type of association along the grazing gradient. We conclude that in the present plant community, grazing-resistant species compete among themselves and segregate in space. Some shrub species act as refuges for grazing-sensitive species that benefit from being spatially associated with shrub species, particularly at intermediate grazing intensities where positive associations were highest. At high grazing intensity, these shrubs can no longer persist and positive associations decrease due to the disappearance of refuges. Spatial associations between plant species and their response to grazing help identify the factors that organize plant communities, and may contribute to improving management of semi-arid ecosystems. PMID:22792367

Saiz, Hugo; Alados, Concepción L.

2012-01-01

337

Divergent composition but similar function of soil food webs of individual plants: plant species and community effects.  

PubMed

Soils are extremely rich in biodiversity, and soil organisms play pivotal roles in supporting terrestrial life, but the role that individual plants and plant communities play in influencing the diversity and functioning of soil food webs remains highly debated. Plants, as primary producers and providers of resources to the soil food web, are of vital importance for the composition, structure, and functioning of soil communities. However, whether natural soil food webs that are completely open to immigration and emigration differ underneath individual plants remains unknown. In a biodiversity restoration experiment we first compared the soil nematode communities of 228 individual plants belonging to eight herbaceous species. We included grass, leguminous, and non-leguminous species. Each individual plant grew intermingled with other species, but all plant species had a different nematode community. Moreover, nematode communities were more similar when plant individuals were growing in the same as compared to different plant communities, and these effects were most apparent for the groups of bacterivorous, carnivorous, and omnivorous nematodes. Subsequently, we analyzed the composition, structure, and functioning of the complete soil food webs of 58 individual plants, belonging to two of the plant species, Lotus corniculatus (Fabaceae) and Plantago lanceolata (Plantaginaceae). We isolated and identified more than 150 taxa/groups of soil organisms. The soil community composition and structure of the entire food webs were influenced both by the species identity of the plant individual and the surrounding plant community. Unexpectedly, plant identity had the strongest effects on decomposing soil organisms, widely believed to be generalist feeders. In contrast, quantitative food web modeling showed that the composition of the plant community influenced nitrogen mineralization under individual plants, but that plant species identity did not affect nitrogen or carbon mineralization or food web stability. Hence, the composition and structure of entire soil food webs vary at the scale of individual plants and are strongly influenced by the species identity of the plant. However, the ecosystem functions these food webs provide are determined by the identity of the entire plant community. PMID:21058562

Bezemer, T M; Fountain, M T; Barea, J M; Christensen, S; Dekker, S C; Duyts, H; van Hal, R; Harvey, J A; Hedlund, K; Maraun, M; Mikola, J; Mladenov, A G; Robin, C; de Ruiter, P C; Scheu, S; Setälä, H; Smilauer, P; van der Putten, W H

2010-10-01

338

The SbSOS1 gene from the extreme halophyte Salicornia brachiata enhances Na+ loading in xylem and confers salt tolerance in transgenic tobacco  

PubMed Central

Background Soil salinity adversely affects plant growth and development and disturbs intracellular ion homeostasis resulting cellular toxicity. The Salt Overly Sensitive 1 (SOS1) gene encodes a plasma membrane Na+/H+ antiporter that plays an important role in imparting salt stress tolerance to plants. Here, we report the cloning and characterisation of the SbSOS1 gene from Salicornia brachiata, an extreme halophyte. Results The SbSOS1 gene is 3774 bp long and encodes a protein of 1159 amino acids. SbSOS1 exhibited a greater level of constitutive expression in roots than in shoots and was further increased by salt stress. Overexpressing the S. brachiata SbSOS1 gene in tobacco conferred high salt tolerance, promoted seed germination and increased root length, shoot length, leaf area, fresh weight, dry weight, relative water content (RWC), chlorophyll, K+/Na+ ratio, membrane stability index, soluble sugar, proline and amino acid content relative to wild type (WT) plants. Transgenic plants exhibited reductions in electrolyte leakage, reactive oxygen species (ROS) and MDA content in response to salt stress, which probably occurred because of reduced cytosolic Na+ content and oxidative damage. At higher salt stress, transgenic tobacco plants exhibited reduced Na+ content in root and leaf and higher concentrations in stem and xylem sap relative to WT, which suggests a role of SbSOS1 in Na+ loading to xylem from root and leaf tissues. Transgenic lines also showed increased K+ and Ca2+ content in root tissue compared to WT, which reflect that SbSOS1 indirectly affects the other transporters activity. Conclusions Overexpression of SbSOS1 in tobacco conferred a high degree of salt tolerance, enhanced plant growth and altered physiological and biochemical parameters in response to salt stress. In addition to Na+ efflux outside the plasma membrane, SbSOS1 also helps to maintain variable Na+ content in different organs and also affect the other transporters activity indirectly. These results broaden the role of SbSOS1 in planta and suggest that this gene could be used to develop salt-tolerant transgenic crops. PMID:23057782

2012-01-01

339

Plant species distributions along environmental gradients: do belowground interactions with fungi matter?  

PubMed Central

The distribution of plants along environmental gradients is constrained by abiotic and biotic factors. Cumulative evidence attests of the impact of biotic factors on plant distributions, but only few studies discuss the role of belowground communities. Soil fungi, in particular, are thought to play an important role in how plant species assemble locally into communities. We first review existing evidence, and then test the effect of the number of soil fungal operational taxonomic units (OTUs) on plant species distributions using a recently collected dataset of plant and metagenomic information on soil fungi in the Western Swiss Alps. Using species distribution models (SDMs), we investigated whether the distribution of individual plant species is correlated to the number of OTUs of two important soil fungal classes known to interact with plants: the Glomeromycetes, that are obligatory symbionts of plants, and the Agaricomycetes, that may be facultative plant symbionts, pathogens, or wood decayers. We show that including the fungal richness information in the models of plant species distributions improves predictive accuracy. Number of fungal OTUs is especially correlated to the distribution of high elevation plant species. We suggest that high elevation soil show greater variation in fungal assemblages that may in turn impact plant turnover among communities. We finally discuss how to move beyond correlative analyses, through the design of field experiments manipulating plant and fungal communities along environmental gradients. PMID:24339830

Pellissier, Loïc; Pinto-Figueroa, Eric; Niculita-Hirzel, Hélène; Moora, Mari; Villard, Lucas; Goudet, Jérome; Guex, Nicolas; Pagni, Marco; Xenarios, Ioannis; Sanders, Ian; Guisan, Antoine

2013-01-01

340

Influence of N 2 -fixing Trifolium on plant species composition and biomass production in alpine tundra  

Microsoft Academic Search

Alpine Trifolium species have high rates of symbiotic N2-fixation which may influence the abundance and growth of plant species growing near them. The potential for facilitative\\u000a effects on plant abundance and growth in dry meadow alpine tundra of Niwot Ridge, Colo., characterized by low resource availability,\\u000a was investigated by measuring soil N, aboveground biomass production, and plant species composition in

Brian D. Thomas; William D. Bowman

1998-01-01

341

Mycorrhizal associations in woody plant species at the Mt. Usu volcano, Japan  

Microsoft Academic Search

We investigated the association between ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungi and pioneer woody plant\\u000a species in areas devastated by the eruption of Mt. Usu, Japan, in 2000. We observed eight woody plant species at the research\\u000a site, most of which were associated with ECM and\\/or AM fungi. In particular, dominant woody plant species Populus\\u000a maximowiczii, Salix\\u000a hultenii var.

Keisuke Obase; Yutaka Tamai; Takashi Yajima; Toshizumi Miyamoto

2007-01-01

342

Increased Plant Carbon Translocation Linked to Overyielding in Grassland Species Mixtures  

PubMed Central

Plant species richness and productivity often show a positive relationship, but the underlying mechanisms are not fully understood, especially at the plant species level. We examined how growing plants in species mixture influences intraspecific rates of short-term carbon (C-) translocation, and determined whether such short-term responses are reflected in biomass yields. We grew monocultures and mixtures of six common C3 grassland plant species in outdoor mesocosms, applied a 13C-CO2 pulse in situ to trace assimilated C through plants, into the soil, and back to the atmosphere, and quantified species-specific biomass. Pulse derived 13C enrichment was highest in the legumes Lotus corniculatus and Trifolium repens, and relocation (i.e. transport from the leaves to other plant parts) of the recently assimilated 13C was most rapid in T. repens grown in 6-species mixtures. The grass Anthoxanthum odoratum also showed high levels of 13C enrichment in 6-species mixtures, while 13C enrichment was low in Lolium perenne, Plantago lanceolata and Achillea millefolium. Rates of C loss through respiration were highest in monocultures of T. repens and relatively low in species mixtures, while the proportion of 13C in the respired CO2 was similar in monocultures and mixtures. The grass A. odoratum and legume T. repens were most promoted in 6-species mixtures, and together with L. corniculatus, caused the net biomass increase in 6-species mixtures. These plant species also had highest rates of 13C-label translocation, and for A. odoratum and T. repens this effect was greatest in plant individuals grown in species mixtures. Our study reveals that short-term plant C translocation can be accelerated in plant individuals of legume and C3 grass species when grown in mixtures, and that this is strongly positively related to overyielding. These results demonstrate a mechanistic coupling between changes in intraspecific plant carbon physiology and increased community level productivity in grassland systems. PMID:23049893

De Deyn, Gerlinde B.; Quirk, Helen; Oakley, Simon; Ostle, Nick J.; Bardgett, Richard D.

2012-01-01

343

Increased plant carbon translocation linked to overyielding in grassland species mixtures.  

PubMed

Plant species richness and productivity often show a positive relationship, but the underlying mechanisms are not fully understood, especially at the plant species level. We examined how growing plants in species mixture influences intraspecific rates of short-term carbon (C-) translocation, and determined whether such short-term responses are reflected in biomass yields. We grew monocultures and mixtures of six common C3 grassland plant species in outdoor mesocosms, applied a (13)C-CO(2) pulse in situ to trace assimilated C through plants, into the soil, and back to the atmosphere, and quantified species-specific biomass. Pulse derived (13)C enrichment was highest in the legumes Lotus corniculatus and Trifolium repens, and relocation (i.e. transport from the leaves to other plant parts) of the recently assimilated (13)C was most rapid in T. repens grown in 6-species mixtures. The grass Anthoxanthum odoratum also showed high levels of (13)C enrichment in 6-species mixtures, while (13)C enrichment was low in Lolium perenne, Plantago lanceolata and Achillea millefolium. Rates of C loss through respiration were highest in monocultures of T. repens and relatively low in species mixtures, while the proportion of (13)C in the respired CO(2) was similar in monocultures and mixtures. The grass A. odoratum and legume T. repens were most promoted in 6-species mixtures, and together with L. corniculatus, caused the net biomass increase in 6-species mixtures. These plant species also had highest rates of (13)C-label translocation, and for A. odoratum and T. repens this effect was greatest in plant individuals grown in species mixtures. Our study reveals that short-term plant C translocation can be accelerated in plant individuals of legume and C3 grass species when grown in mixtures, and that this is strongly positively related to overyielding. These results demonstrate a mechanistic coupling between changes in intraspecific plant carbon physiology and increased community level productivity in grassland systems. PMID:23049893

De Deyn, Gerlinde B; Quirk, Helen; Oakley, Simon; Ostle, Nick J; Bardgett, Richard D

2012-01-01

344

Species richness in a successional grassland: effects of nitrogen enrichment and plant litter  

E-print Network

We conducted a field experiment in a successional grassland to investigate the short-term effects of nitrogen enrichment and plant litter on plant species richness and on the establishment of a native grass (Andropogon gerardi...

Foster, Bryan L.; Gross, Katherine L.

1998-12-01

345

Forty-nine New Host Plant Species for Bemisia tabaci (Hemiptera: Aleyrodidae)  

Technology Transfer Automated Retrieval System (TEKTRAN)

The sweetpotato whitefly, Bemisia tabaci (Gennadius), is a worldwide pest of numerous agricultural and ornamental crops. In addition to directly feeding on plants, it also acts as a vector of plant viruses of cultivated and uncultivated host plant species. Moreover, host plants can affect the popula...

346

Reciprocal Effects of Litter from Exotic and Congeneric Native Plant Species via Soil Nutrients  

PubMed Central

Invasive exotic plant species are often expected to benefit exclusively from legacy effects of their litter inputs on soil processes and nutrient availability. However, there are relatively few experimental tests determining how litter of exotic plants affects their own growth conditions compared to congeneric native plant species. Here, we test how the legacy of litter from three exotic plant species affects their own performance in comparison to their congeneric natives that co-occur in the invaded habitat. We also analyzed litter effects on soil processes. In all three comparisons, soil with litter from exotic plant species had the highest respiration rates. In two out of the three exotic-native species comparisons, soil with litter from exotic plant species had higher inorganic nitrogen concentrations than their native congener, which was likely due to higher initial litter quality of the exotics. When litter from an exotic plant species had a positive effect on itself, it also had a positive effect on its native congener. We conclude that exotic plant species develop a legacy effect in soil from the invaded range through their litter inputs. This litter legacy effect results in altered soil processes that can promote both the exotic plant species and their native congener. PMID:22359604

Meisner, Annelein; de Boer, Wietse; Cornelissen, Johannes H. C.; van der Putten, Wim H.

2012-01-01

347

Regional data refine local predictions: modeling the distribution of plant species abundance on a portion  

E-print Network

habitats to species invasions (Stohlgren et al. 2002), estimating species richness (Graham and Hijmans 2006Regional data refine local predictions: modeling the distribution of plant species abundance September 2011 # Springer Science+Business Media B.V. 2011 Abstract Species distribution models

MacDonald, Lee

348

Vascular plant and vertebrate species richness in national parks of the eastern United States  

USGS Publications Warehouse

Given the estimates that species diversity is diminishing at 50-100 times the normal rate, it is critical that we be able to evaluate changes in species richness in order to make informed decisions for conserving species diversity. In this study, we examined the potential of vascular plant species richness to be used as a surrogate for vertebrate species richness in the classes of amphibians, reptiles, birds, and mammals. Vascular plants, as primary producers, represent the biotic starting point for ecological community structure and are the logical place to start for understanding vertebrate species associations. We used data collected by the United States (US) National Park Service (NPS) on species presence within parks in the eastern US to estimate simple linear regressions between plant species richness and vertebrate richness. Because environmental factors may also influence species diversity, we performed simple linear regressions of species richness versus natural logarithm of park area, park latitude, mean annual precipitation, mean annual temperature, and human population density surrounding the parks. We then combined plant species richness and environmental variables in multiple regressions to determine the variables that remained as significant predictors of vertebrate species richness. As expected, we detected significant relationships between plant species richness and amphibian, bird, and mammal species richness. In some cases, plant species richness was predicted by park area alone. Species richness of mammals was only related to plant species richness. Reptile species richness, on the other hand, was related to plant species richness, park latitude and annual precipitation, while amphibian species richness was related to park latitude, park area, and plant species richness. Thus, plant species richness predicted species richness of different vertebrate groups to varying degrees and should not be used exclusively as a surrogate for vertebrate species richness. Plant species richness should be included with other variables such as area and climate when considering strategies to manage and conserve species in US National Parks. It is not always appropriate to draw conclusions about analyses of taxonomic surrogates from one area to another. Two patterns evident from the linear regressions were the increase in species richness with the increase of park area and with increase of vascular plant species richness. To test whether there were differences in these patterns among networks, we used analysis of covariance (ANCOVA). Differences among networks were detected only in bird species richness versus plant species richness and for all taxa except mammals for vertebrate species richness versus park area. Some of these results may be due to small sample size among networks, and therefore, low statistical power. Other factors that could have contributed to these results were differences in average park area and habitat heterogeneity among networks, latitudinal gradients, low variation in mean annual precipitation, and different use of vegetation by migratory species. Based on these results we recommend that management of biodiversity be approached from local and site specific criteria rather than applying management directives derived from other regions of the US. It is also recommended that analyses similar to those presented here be conducted for all national parks, once data become available for all networks in the US, to gain a better understanding of how vascular plant species richness, area, and vertebrate species richness are related in the US.

Hatfield, Jeffrey S.; Myrick, Kaci E.; Huston, Michael A.; Weckerly, Floyd W.; Green, M. Clay

2013-01-01

349

Effects of arbuscular mycorrhizal colonisation on shoot and root decomposition of different plant species and species mixtures  

Microsoft Academic Search

We studied the decomposition of shoot and root tissues of four plant species from central Argentina belonging to contrasting functional types: a deciduous shrub (Acacia caven), a perennial forb (Hyptis mutabilis), an annual forb (Bidens pilosa) and a tussock grass (Jarava pseudoichu). They were grown from seed in a greenhouse in isolation or in 2- or 4-species mixtures, with and

Carlos Urcelay; María Victoria Vaieretti; Marisela Pérez; Sandra Díaz

2011-01-01

350

Interactions of plant zinc and plant species on the bioavailability of plant cadmium to Japanese quail fed lettuce and spinach  

SciTech Connect

Many cadmium-contaminated environments contain high levels of zinc. The effects of plant Zn and plant species on plant Cd bioavailability were tested in Japanese quail fed lettuce and spinach. Four groups of birds received 10% of their diets as lettuce or spinach leaves intrinsically labeled with {sup 109}Cd and containing low or high intrinsic Zn. Two other groups were fed control diets containing {sup 109}Cd as CdSO{sub 4} and low or high Zn as ZnCO{sub 3}. Cadmium concentrations in diets ranged from 0.857 to 1.05 {mu}g/g dry wt. Zinc concentrations in low-Zn diets ranged from 21.2 to 22.8, and in high-Zn diets from 56.0 to 63.3 {mu}g/g dry wt. Increased lettuce and spinach Zn decreased plant Cd retention in kidney, liver, and jejunum-ileum of Japanese quail. Spinach Cd was less absorbed than lettuce Cd at both Zn levels. Inorganic Zn produced a lesser decrease in Cd retention in kidney, liver, and jejunum-ileum than did plant Zn. The authors conclude that (1) crops that transport Zn and Cd readily into edible tissues show lower Cd bioavailability when grown in Zn-Cd contaminated environments than in Cd-only polluted sites, (2) plant species differ in Cd bioavailability for identical concentrations of Zn and Cd in edible tissues, and (3) toxicological studies with animals exposed to Cd salts and Zn supplements do not assess Cd bioavailability of Zn-Cd contaminated crops.

McKenna, I.M.; Keach, R.M. Jr; Williams, F.M. (Pennsylvania State Univ., University Park (United States)); Chaney, R.L. (Pennsylvania State Univ., University Park (United States) Dept. of Agriculture, Beltsville, MD (United States)); Tao, Shyy-Hwa (Food and Drug Administration, Washington, DC (United States))

1992-02-01

351

Seasonal dependent effects of flooding on plant species survival and zonation: a comparative study of 10 terrestrial grassland species  

Microsoft Academic Search

Past research has provided compelling evidence that variation in flooding duration is the predominant factor underlying plant\\u000a species distribution along elevation gradients in river floodplains. The role of seasonal variation in flooding, however,\\u000a is far from clear. We addressed this seasonal effect for 10 grassland species by testing the hypothesis that all species can\\u000a survive longer when flooded in winter

W. H. J. M. Eck; J. P. M. Lenssen; H. M. Steeg; C. W. P. M. Blom; H. Kroon

352

Seasonal Dependent Effects of Flooding on Plant Species Survival and Zonation: a Comparative Study of 10 Terrestrial Grassland Species  

Microsoft Academic Search

Past research has provided compelling evidence that variation in flooding duration is the predominant factor underlying plant\\u000a species distribution along elevation gradients in river floodplains. The role of seasonal variation in flooding, however,\\u000a is far from clear. We addressed this seasonal effect for 10 grassland species by testing the hypothesis that all species can\\u000a survive longer when flooded in winter

J. P. M. Lenssen; H. M. van de Steeg; C. W. P. M. Blom; H. de Kroon

2006-01-01

353

Plant species identity surpasses species richness as a key driver of N(2)O emissions from grassland.  

PubMed

Grassland ecosystems worldwide not only provide many important ecosystem services but they also function as a major source of the greenhouse gas nitrous oxide (N2O), especially in response to nitrogen deposition by grazing animals. To explore the role of plants as mediators of these emissions, we tested whether and how N2O emissions are dependent on grass species richness and/or specific grass species composition in the absence and presence of urine deposition. We hypothesized that: (i) N2O emissions relate negatively to plant productivity; (ii) four-species mixtures have lower emissions than monocultures (as they are expected to be more productive); (iii) emissions are lowest in combinations of species with diverging root morphology and high root biomass; and (iv) the identity of the key species that reduce N2O emissions is dependent on urine deposition. We established monocultures and two- and four-species mixtures of common grass species with diverging functional traits: Lolium perenne L. (Lp), Festuca arundinacea Schreb. (Fa), Phleum pratense L. (Php) and Poa trivialis L. (Pt), and quantified N2O emissions for 42 days. We found no relation between plant species richness and N2O emissions. However, N2O emissions were significantly reduced in specific plant species combinations. In the absence of urine, plant communities of Fa+Php acted as a sink for N2O, whereas the monocultures of these species constituted a N2O source. With urine application Lp+Pt plant communities reduced (P < 0.001) N2O emissions by 44% compared to monocultures of Lp. Reductions in N2O emissions by species mixtures could be explained by total biomass productivity and by complementarity in root morphology. This study shows that plant species composition is a key component underlying N2O emissions from grassland ecosystems. Selection of specific grass species combinations in the context of the expected nitrogen deposition regimes may therefore provide a key for mitigation of N2O emissions. PMID:23939815

Abalos, Diego; De Deyn, Gerlinde B; Kuyper, Thomas W; Van Groenigen, Jan Willem

2014-01-01

354

Invasive plant species as potential bioenergy producers and carbon contributors.  

SciTech Connect

Current cellulosic bioenergy sources in the United States are being investigated in an effort to reduce dependence on foreign oil and the associated risks to national security and climate change (Koh and Ghazoul 2008; Demirbas 2007; Berndes et al. 2003). Multiple sources of renewable plant-based material have been identified and include agricultural and forestry residues, municipal solid waste, industrial waste, and specifically grown bioenergy crops (Demirbas et al. 2009; Gronowska et al. 2009). These sources are most commonly converted to energy through direct burning, conversion to gas, or conversion to ethanol. Annual crops, such as corn (Zea Mays L.) and sorghum grain, can be converted to ethanol through fermentation, while soybean and canola are transformed into fatty acid methyl esters (biodiesel) by reaction with an alcohol (Demirbas 2007). Perennial grasses are one of the more viable sources for bioenergy due to their continuous growth habit, noncrop status, and multiple use products (Lewandowski el al. 2003). In addition, a few perennial grass species have very high water and nutrient use efficiencies producing large quantities of biomass on an annual basis (Dohleman et al. 2009; Grantz and Vu 2009).

Young, S.; Gopalakrishnan, G.; Keshwani, D. (Energy Systems); (Univ. of Nebraska)

2011-03-01

355

Nutritional and cultural aspects of plant species selection for a controlled ecological life support system  

NASA Technical Reports Server (NTRS)

The feasibility of using higher plants in a controlled ecological life support system is discussed. Aspects of this system considered important in the use of higher plants include: limited energy, space, and mass, and problems relating to cultivation and management of plants, food processing, the psychological impact of vegetarian diets, and plant propagation. A total of 115 higher plant species are compared based on 21 selection criteria.

Hoff, J. E.; Howe, J. M.; Mitchell, C. A.

1982-01-01

356

Effects of invasive plant species on pollinator service and reproduction in native plants at Acadia National Park  

USGS Publications Warehouse

Invasive plant species can have profound negative effects on natural communities by competively excluding native species. Berberis thunbergii (Japanese barberry), Frangula alnus (glossy or alder buckthorn) and Lythrum salicaria (purple loosestrife) are invasive species known to reduce native plant diversity and are thus of great concern to Acadia National Park. Pollinators visit them for nectar and pollen. The effects of invasive plant species on pollinator behavior were investigated by comparing pollinator visitation to co-flowering native and invasive species with visitation to native species growing alone. The effect of invasives on pollination of native plants was studied by comparing fruit set in patches of the native species growing near invasives with patches far from invasive species in Acadia National Park. The coflowering pairs were as follows: in the spring native Vaccinium angustifolium (lowbush blueberry) was paired with B. thunbergii; in early summer native Viburnum nudum (wild raisin) was paired with F. alnus ; in late summer native Spiraea alba (meadowsweet) was paired with L. salicaria. We investigated whether these invasives competed with native plants for pollinators in Acadia and thus negatively affected native plant reproduction. Our objectives were to determine: 1) the influence, if any, of each invasive on pollinator visitation to a co-flowering native species, 2) factors that might affect visitation, 3) invasive pollen transfer to native plants, and 4) whether invasives influence native plant reproduction (fruit set). Our findings indicate that at times the number of flower visitors to natives was lower or the species composition of visitors different when invasives were present, that invasives sometimes attracted more pollinators, that generally the invasives were more rewarding as far as nectar and pollen availability for pollinators, and that generally native plant fruit set and seed set was not significantly lowered in the presence of the invasive. In fact, in one year fruit set of S. alba was significantly greater in the presence of L. salicaria. The number of invasive pollen grains on native stigmas was extremely low; on average less than one grain per stigma. These fruit set and pollen deposition findings indicate that native plant reproduction was not adversely affected in the short term by these invasive species and that therefore competition between the native and invasive species for pollinators did not occur. Native bee populations monitored in 2004-2005 at sites with and without B. thunbergii and/or F. alnus indicated a greater abundance of native bees at sites with these invasives present. Native bees collected from the native and invasive plants were compared with historical records to assess whether invasive plants favor different bee species than those that formerly predominated on Mount Desert Island. This does not appear to be the case. Several species of bumble bees (Bombus spp.) as well as nine solitary bee species were found that were not documented by the Procter surveys of 1917-1940. Collecting of native bees was limited to the study plants, which may, in part, explain why some bee species documented in the Procter Surveys were not found in the present research. A field guide for identification of native bumble bees has been produced to help Park Natural Resource personnel monitor the status of native bee populations in Acadia. Other educational materials were also developed, aimed at educating Park visitors by exposing them to: 1) the role of native plants and their bee pollinators in terrestrial ecosystems; 2) the effects of invasive plants on native plant-pollinator mutualisms; 3) the need for conserving native bees and other pollinators; and 4) conservation strategies for protecting and enhancing native plant-pollinator mutualisms in the Park. Based on the present findings, Acadia Park Resource Management personnel should continue to closely

Stubbs, C.J.; Drummond, F.; Ginsberg, H.

2007-01-01

357

The impacts of individual plant species on rhizosphere microbial communities in soils of different fertility  

Microsoft Academic Search

To investigate the effects of individual plant species on microbial community properties in soils of differing fertility, a microcosm experiment was carried out using plant species representative of the dominant flora in semi-fertile temperate grasslands of northern England. Soil microbial biomass and activity were found to be significantly greater in the more fertile, agriculturally improved soil than in the less

Louise Innes; Philip J. Hobbs; Richard D. Bardgett

2004-01-01

358

Quality over quantity: buffer strips can be improved with select native plant species.  

PubMed

Native plants attractive to beneficial insects may improve the value of buffer strips by increasing biodiversity and enhancing the delivery of insect-derived ecosystem services. In a 2-yr field experiment, we measured the response of insect communities across nine buffers that varied in plant diversity. We constructed buffers with plants commonly found in buffers of USDA-certified organic farms in Iowa (typically a single species), recommended for prairie reconstruction, or recommended for attracting beneficial insects. We hypothesized that the diversity and abundance of beneficial insects will be 1) greatest in buffers composed of diverse plant communities with continuous availability of floral resources, 2) intermediate in buffers with reduced species richness and availability of floral resources, and 3) lowest in buffers composed of a single species. We observed a significant positive relationship between the diversity and abundance of beneficial insects with plant community diversity and the number of flowers. More beneficial insects were collected in buffers composed of species selected for their attractiveness to beneficial insects than a community recommended for prairie restoration. These differences suggest 1) plant communities that dominate existing buffers are not optimal for attracting beneficial insects, 2) adding flowering perennial species could improve buffers as habitat for beneficial insects, 3) buffers can be optimized by intentionally combining the most attractive native species even at modest levels of plant diversity, and 4) plant communities recommended for prairie reconstruction may not contain the optimal species or density of the most attractive species necessary to support beneficial insects from multiple guilds. PMID:24763090

Gill, K A; Cox, R; O'Neal, M E

2014-04-01

359

OIKOS 104: 336344, 2004 Litter effects of two co-occurring alpine species on plant growth,  

E-print Network

OIKOS 104: 336­344, 2004 Litter effects of two co-occurring alpine species on plant growth. and Meier, C. L. 2004. Litter effects of two co-occurring alpine species on plant growth, microbial activity and immobilization of nitrogen. ­ Oikos 104: 336­344. We measured the litter chemistry of two co-dominant alpine

Cleveland, Cory

360

Widespread Paleopolyploidy in Model Plant Species Inferred from Age Distributions of Duplicate Genes  

Microsoft Academic Search

It is often anticipated that many of today's diploid plant species are in fact paleopolyploids. Given that an ancient large-scale duplication will result in an excess of relatively old duplicated genes with similar ages, we analyzed the timing of duplication of pairs of paralogous genes in 14 model plant species. Using EST contigs (unigenes), we identified pairs of paralogous genes

Guillaume Blanca; Kenneth H. Wolfe

361

Hydrocarbon and rubber-producing crops: evaluation of 100 US plant species  

Microsoft Academic Search

Agricultural production of rubber and other hydrocarbons in the United States may be compatible with increased food and fiber production if entire plants are harvested and processed for fiber, protein, and carbohydrate as well. Procedures and criteria have been established for the preliminary evaluation of plant species as potential multi-use hydrocarbon-producing crops. Previously, 106 species representing 44 families and 81

R. T. Buchanan; I. M. Cull; F. H. Otey; C. R. Russell

1978-01-01

362

Comparative electrophysiological analysis of plant odor perception in females of three Papilio species  

Microsoft Academic Search

Summary Antennae of femalePapilio butterflies perceive many volatile plant constituents with widely differing, constituent-specific sensitivities. We compared the responses of threePapilio species to volatiles from host and non-host plants to assess species-specificity and the degree of evolutionary conservatism in olfactory responses.

Robert Baur; Paul Feeny

1994-01-01

363

Impact of invasive plants on the species richness, diversity and composition of invaded communities  

Microsoft Academic Search

Summary 1. Much attention has been paid to negative effects of alien species on resident communities but studies that quantify community-level effects of a number of invasive plants are scarce. We address this issue by assessing the impact of 13 species invasive in the Czech Republic on a wide range of plant communities. 2. Vegetation in invaded and uninvaded plots

Martin Hejda; Petr Pyšek; Vojt?ch Jarošík

2009-01-01

364

Phenotypic selection on flowering phenology and size in two dioecious plant species with different pollen vectors  

E-print Network

Phenotypic selection on flowering phenology and size in two dioecious plant species with different vectors might impose contrasting selective pressures on plant flowering phenology. In the present study we describe the flowering phenology of two sympatric dioecious species with contrasting pollination modes

Northampton, University of

365

Host-plant species modifies the diet of an omnivore feeding on three trophic levels  

E-print Network

Host-plant species modifies the diet of an omnivore feeding on three trophic levels Sara Magalha. and Sabelis, M. W. 2005. Host-plant species modifies the diet of an omnivore feeding on three trophic levels. Á/ Oikos 111: 47Á/56. The diet choice of omnivores feeding on two adjacent trophic levels (either

Magalhães, Sara

366

Dormancy cycling and persistence of seeds in soil of a cold desert halophyte shrub  

PubMed Central

Background and Aims Formation of seed banks and dormancy cycling are well known in annual species, but not in woody species. In this study it was hypothesized that the long-lived halophytic cold desert shrub Kalidium gracile has a seed bank and dormancy cycling, which help restrict germination to a favourable time for seedling survival. Methods Fresh seeds were buried in November 2009 and exhumed and tested for germination monthly from May 2010 to December 2011 over a range of temperatures and salinities. Germination recovery and viability were determined after exposure to salinity and water stress. Seedling emergence and dynamics of the soil seed bank were investigated in the field. Key Results Seeds of K. gracile had a soil seed bank of 7030 seeds m?2 at the beginning of the growing season. About 72 % of the seeds were depleted from the soil seed bank during a growing season, and only 1·4 % of them gave rise to seedlings that germinated early enough to reach a stage of growth at which they could survive to overwinter. About 28 % of the seeds became part of a persistent soil seed bank. Buried seeds exhibited an annual non-dormancy/conditional dormancy (ND/CD) cycle, and germination varied in sensitivity to salinity during the cycle. Dormancy cycling is coordinated with seasonal environmental conditions in such a way that the seeds germinate in summer, when there is sufficient precipitation for seedling establishment. Conclusions Kalidium gracile has three life history traits that help ensure persistence at a site: a polycarpic perennial life cycle, a persistent seed bank and dormancy cycling. The annual ND/CD cycle in seeds of K. gracile contributes to seedling establishment of this species in the unpredictable desert environment and to maintenance of a persistent soil seed bank. This is the first report of a seed dormancy cycle in a cold desert shrub. PMID:24249808

Cao, Dechang; Baskin, Carol C.; Baskin, Jerry M.; Yang, Fan; Huang, Zhenying

2014-01-01

367

Plant species coexistence at local scale in temperate swamp forest: test of habitat heterogeneity hypothesis.  

PubMed

It has been suggested that a heterogeneous environment enhances species richness and allows for the coexistence of species. However, there is increasing evidence that environmental heterogeneity can have no effect or even a negative effect on plant species richness and plant coexistence at a local scale. We examined whether plant species richness increases with local heterogeneity in the water table depth, microtopography, pH and light availability in a swamp forest community at three local spatial scales (grain: 0.6, 1.2 and 11.4 m). We also used the variance partitioning approach to assess the relative contributions of niche-based and other spatial processes to species occurrence. We found that heterogeneity in microtopography and light availability positively correlated with species richness, in accordance with the habitat heterogeneity hypothesis. However, we recorded different heterogeneity-diversity relationships for particular functional species groups. An increase in the richness of bryophytes and woody plant species was generally related to habitat heterogeneity at all measured spatial scales, whereas a low impact on herbaceous species richness was recorded only at the 11.4 m scale. The distribution of herbaceous plants was primarily explained by other spatial processes, such as dispersal, in contrast to the occurrence of bryophytes, which was better explained by environmental factors. Our results suggest that both niche-based and other spatial processes are important determinants of the plant composition and species turnover at local spatial scales in swamp forests. PMID:22139430

Douda, Jan; Doudová-Kochánková, Jana; Boublík, Karel; Drašnarová, Alena

2012-06-01

368

Vegetation classification and the efficacy of plant dominance-based classifications in predicting the occurrence of plant and animal species  

E-print Network

the complementarity of an evergreen forest and a deciduous forest. I also evaluated a dichotomy of subsoil texture. I compared 6 groups of species: (1) woody plants (Dicotyledonae), (2) birds (Aves), (3) small mammals (Mammalia) plus herptiles (Amphibia) and (Reptilia...

Yantis, James Hugh

2006-10-30

369

Plant Species Classification using a 3D LIDAR Sensor and Machine Learning Ulrich Weiss and Peter Biber  

E-print Network

Plant Species Classification using a 3D LIDAR Sensor and Machine Learning Ulrich Weiss and Peter of the plant and species. Automatically distinguishing between plant species is a challenging task, because of the appearances and the differences between the plants used by humans, into a formal, computer understandable form

Zell, Andreas

370

Are Non-Native Plants Perceived to Be More Risky? Factors Influencing Horticulturists' Risk Perceptions of Ornamental Plant Species  

PubMed Central

Horticultural trade is recognized as an important vector in promoting the introduction and dispersal of harmful non-native plant species. Understanding horticulturists' perceptions of biotic invasions is therefore important for effective species risk management. We conducted a large-scale survey among horticulturists in Switzerland (N?=?625) to reveal horticulturists' risk and benefit perceptions from ornamental plant species, their attitudes towards the regulation of non-native species, as well as the factors decisive for environmental risk perceptions and horticulturists' willingness to engage in risk mitigation behavior. Our results suggest that perceived familiarity with a plant species had a mitigating effect on risk perceptions, while perceptions of risk increased if a species was perceived to be non-native. However, perceptions of the non-native origin of ornamental plant species were often not congruent with scientific classifications. Horticulturists displayed positive attitudes towards mandatory trade regulations, particularly towards those targeted against known invasive species. Participants also expressed their willingness to engage in risk mitigation behavior. Yet, positive effects of risk perceptions on the willingness to engage in risk mitigation behavior were counteracted by perceptions of benefits from selling non-native ornamental species. Our results indicate that the prevalent practice in risk communication to emphasize the non-native origin of invasive species can be ineffective, especially in the case of species of high importance to local industries and people. This is because familiarity with these plants can reduce risk perceptions and be in conflict with scientific concepts of non-nativeness. In these cases, it might be more effective to focus communication on well-documented environmental impacts of harmful species. PMID:25003195

Humair, Franziska; Kueffer, Christoph; Siegrist, Michael

2014-01-01

371

Are non-native plants perceived to be more risky? Factors influencing horticulturists' risk perceptions of ornamental plant species.  

PubMed

Horticultural trade is recognized as an important vector in promoting the introduction and dispersal of harmful non-native plant species. Understanding horticulturists' perceptions of biotic invasions is therefore important for effective species risk management. We conducted a large-scale survey among horticulturists in Switzerland (N?=?625) to reveal horticulturists' risk and benefit perceptions from ornamental plant species, their attitudes towards the regulation of non-native species, as well as the factors decisive for environmental risk perceptions and horticulturists' willingness to engage in risk mitigation behavior. Our results suggest that perceived familiarity with a plant species had a mitigating effect on risk perceptions, while perceptions of risk increased if a species was perceived to be non-native. However, perceptions of the non-native origin of ornamental plant species were often not congruent with scientific classifications. Horticulturists displayed positive attitudes towards mandatory trade regulations, particularly towards those targeted against known invasive species. Participants also expressed their willingness to engage in risk mitigation behavior. Yet, positive effects of risk perceptions on the willingness to engage in risk mitigation behavior were counteracted by perceptions of benefits from selling non-native ornamental species. Our results indicate that the prevalent practice in risk communication to emphasize the non-native origin of invasive species can be ineffective, especially in the case of species of high importance to local industries and people. This is because familiarity with these plants can reduce risk perceptions and be in conflict with scientific concepts of non-nativeness. In these cases, it might be more effective to focus communication on well-documented environmental impacts of harmful species. PMID:25003195

Humair, Franziska; Kueffer, Christoph; Siegrist, Michael

2014-01-01

372

Plant regeneration via somatic embryogenesis from protoplasts of six plant species related to Citrus.  

PubMed

Protoplasts isolated from embryogenic callus of Fortunella polyandra (Ridl.), Atalantia bilocularis (Pieree ex Guill.), Hesperethusa crenulata (Roxb.), Glycosmis pentaphylla (Retz.) Corr., Triphasia trifolia (Burm. f.) P. Wils. and Murraya koenigii (L.) Spreng. were cultured in MT (Murashige and Tucker 1969) basal medium containing 5% sucrose supplemented with 0.0, 0.001, 0.01, 0.1 or 1.0 mg l(-1) BA and 0.6 M sorbitol. The highest plating efficiencies for all species were obtained on MT basal medium containing 5% sucrose supplemented with 0.001 mg l(-1) BA. F. polyandra produced higher percentages of globular somatic embryo development, while A. bilocularis consistently showed a lower percentage of globular somatic embryo development in all 5 concentrations of BA. MT basal medium containing 5% sucrose and supplemented with 0.001 mg l(-1) BA was found to be a suitable medium for development of globular somatic embryos derived from protoplasts to form heart-shaped somatic embryos with cotyledon-like structures. The highest percentages of shoot formation for all 6 species were obtained using 0.1 mg l(-1) GA3. A complete protoplast-to-plant system was developed for F. polyandra, A. bilocularis and T. trifolia, which could facilitate the transfer of nuclear and cytoplasmic genes from these species into cultivated Citrus through protoplast fusion. PMID:24178352

Jumin, H B; Nito, N

1996-01-01

373

Emission of isoprene from common Indian plant species and its implications for regional air quality  

Microsoft Academic Search

Isoprene is most dominant volatile organic compounds (VOC) emitted by many plants. In this study 40 common Indian plant species\\u000a were examined for isoprene emission using dynamic flow through enclosure chamber technique. Isoprene emission rates of plants\\u000a species were found to vary from undetectable to 69.5 ?g g?1 h?1 (Madhuca latifolia). Besides, an attempt has been made to evaluate suitability of

Rashmi Singh; Abhai Pratap Singh; M. P. Singh; Animesh Kumar; C. K. Varshney

2008-01-01

374

Impact of three aquatic invasive species on native plants and macroinvertebrates in temperate ponds  

Microsoft Academic Search

Biological plant invasions pose a serious threat to native biodiversity and have received much attention, especially in terrestrial\\u000a habitats. In freshwater ecosystems impacts of invasive plant species are less studied. We hypothesized an impact on organisms\\u000a from the water column and from the sediment. We then assessed the impact of three aquatic invasive species on the plants and\\u000a macroinvertebrates: Hydrocotyle

Iris Stiers; Nicolas Crohain; Guy Josens; Ludwig Triest

375

Ecophysiology of cuticular transpiration: comparative investigation of cuticular water permeability of plant species from different habitats  

Microsoft Academic Search

Water permeabilities of astomatous, isolated cuticular membranes (CM) of 24 different plants species were measured. Permeances varied from 1.7×10-11 m·s-1 (Vanilla planifolia leaf) up to 2.1×10-9 m·s-1 (Malus cf. domestica fruit) among different plant species, thus covering a range of over 2 orders of magnitude. Ranking of species according to permeances resulted in four distinct groups. The first group, of

L. Schreiber; M. Riederer

1996-01-01

376

The effect of AMF suppression on plant species composition in a nutrient-poor dry grassland.  

PubMed

Arbuscular mycorrhizal fungi (AMF) are expected to be one of the key drivers determining the diversity of natural plant communities, especially in nutrient-poor and dry habitats. Several previous studies have explored the importance of AMF for the composition of plant communities in various types of habitats. Surprisingly, studies of the role of AMF in nutrient-poor dry grassland communities dominated by less mycotrophic plant species are still relatively rare. We present the results of a 3-year study in which a plant community in a species-rich dry grassland was subjected to the fungicide carbendazim to suppress AMF colonization. We tested the effect of the fungicide on the following parameters: the plant species composition; the number of plant species; the cover of the rare, highly mycorrhiza-dependent species Aster amellus; the cover of the dominant, less mycorrhiza-dependent species Brachypodium pinnatum; and the cover of graminoids and perennial forbs. In addition, we examined the mycorrhizal inoculation potential of the soil. We found that the suppression of AMF with fungicide resulted in substantial changes in plant species composition and significant decrease in species richness, the cover of A. amellus and the cover of perennial forbs. In contrast the species increasing their cover after fungicide application were graminoids--the C3 grasses B. pinnatum and Bromus erectus and the sedge Carex flacca. These species appear to be less mycorrhiza dependent. Moreover, due to their clonal growth and efficient nutrient usage, they are, most likely, better competitors than perennial forbs under fungicide application. Our results thus suggest that AMF are an essential part of the soil communities supporting a high diversity of plant species in species-rich dry grasslands in nutrient-poor habitats. The AMF are especially important for the maintenance of the populations of perennial forbs, many of which are rare and endangered in the area. PMID:24265829

Dostálek, Tomáš; Pánková, Hana; Münzbergová, Zuzana; Rydlová, Jana

2013-01-01

377

The Effect of AMF Suppression on Plant Species Composition in a Nutrient-Poor Dry Grassland  

PubMed Central

Arbuscular mycorrhizal fungi (AMF) are expected to be one of the key drivers determining the diversity of natural plant communities, especially in nutrient-poor and dry habitats. Several previous studies have explored the importance of AMF for the composition of plant communities in various types of habitats. Surprisingly, studies of the role of AMF in nutrient-poor dry grassland communities dominated by less mycotrophic plant species are still relatively rare. We present the results of a 3-year study in which a plant community in a species-rich dry grassland was subjected to the fungicide carbendazim to suppress AMF colonization. We tested the effect of the fungicide on the following parameters: the plant species composition; the number of plant species; the cover of the rare, highly mycorrhiza-dependent species Aster amellus; the cover of the dominant, less mycorrhiza-dependent species Brachypodium pinnatum; and the cover of graminoids and perennial forbs. In addition, we examined the mycorrhizal inoculation potential of the soil. We found that the suppression of AMF with fungicide resulted in substantial changes in plant species composition and significant decrease in species richness, the cover of A. amellus and the cover of perennial forbs. In contrast the species increasing their cover after fungicide application were graminoids—the C3 grasses B. pinnatum and Bromus erectus and the sedge Carex flacca. These species appear to be less mycorrhiza dependent. Moreover, due to their clonal growth and efficient nutrient usage, they are, most likely, better competitors than perennial forbs under fungicide application. Our results thus suggest that AMF are an essential part of the soil communities supporting a high diversity of plant species in species-rich dry grasslands in nutrient-poor habitats. The AMF are especially important for the maintenance of the populations of perennial forbs, many of which are rare and endangered in the area. PMID:24265829

Dostálek, Tomáš; Pánková, Hana; Münzbergová, Zuzana; Rydlová, Jana

2013-01-01

378

Species removal and experimental warming in a subarctic tundra plant community  

Microsoft Academic Search

Neighbor interactions are likely to play an important role in subarctic plant communities. We conducted experiments in Interior\\u000a Alaska in which we crossed species removal with greenhouse warming manipulations. We examined changes in community biomass,\\u000a and in plant survival and growth of individual species in response to experimental warming and to: (1) removal of whole species\\u000a versus an equivalent amount

Christian Rixen; Christa P. H. Mulder

2009-01-01

379

The ability of several high arctic plant species to utilize nitrate nitrogen under field conditions  

Microsoft Academic Search

The ability to utilize NOinf3sup-in seven high arctic plant species from Truelove Lowland, Devon Island, Canada was investigated, using an in vivo assay of maximum potential nitrate reductase (NR) activity and applications of 15N. Plant species were selected on the basis of being characteristic of nutrient-poor and nutrient-rich habitats. In all species leaves were the dominant site of NR activity.

Owen K. Atkin; Rafael Villar; W. Raymond Cummins

1993-01-01

380

Challenging urban species diversity: contrasting phylogenetic patterns across plant functional groups in Germany.  

PubMed

Cities are hotspots of plant species richness, harboring more species than their rural surroundings, at least over large enough scales. However, species richness does not necessarily cover all aspects of biodiversity such as phylogenetic relationships. Ignoring these relationships, our understanding of how species assemblages develop and change in a changing environment remains incomplete. Given the high vascular plant species richness of urbanized areas in Germany, we asked whether these also have a higher phylogenetic diversity than rural areas, and whether phylogenetic diversity patterns differ systematically between species groups characterized by specific functional traits. Calculating the average phylogenetic distinctness of the total German flora and accounting for spatial autocorrelation, we show that phylogenetic diversity of urban areas does not reflect their high species richness. Hence, high urban species richness is mainly due to more closely related species that are functionally similar and able to deal with urbanization. This diminished phylogenetic information might decrease the flora's capacity to respond to environmental changes. PMID:18616547

Knapp, Sonja; Kühn, Ingolf; Schweiger, Oliver; Klotz, Stefan

2008-10-01

381

Increased plant size in exotic populations: a common-garden test with 14 invasive species.  

PubMed

The "evolution of increased competitive ability" (EICA) hypothesis predicts that exotic species will adapt to reduced herbivore pressure by losing costly defenses in favor of competitive ability. Previous studies often support the prediction that plants from exotic populations will be less well defended than plants from native populations. However, results are mixed with respect to the question of whether plants from exotic populations have become more competitive. In a common-garden experiment involving plants from two native and two exotic populations of 14 different invasive species, we tested whether exotic plants generally grow larger than conspecific native plants, and whether patterns of relative growth depend on the intensity of competition. We found a quite consistent pattern of larger exotic than native plants, but only in the absence of competition. These results suggest that invasive species may often evolve increased growth, and that increased growth may facilitate adaptation to noncompetitive environments. PMID:18051644

Blumenthal, Dana M; Hufbauer, Ruth A

2007-11-01

382

Site and species-specific differences in endophyte occurrence in two herbaceous plants  

Microsoft Academic Search

Summary 1 Endophyte fungi exist within the living tissues of all plants, but compared with grasses and trees, remarkably little is known about their ecology in herbaceous species. These fungi produce an array of metabolites in culture and there is some evidence that they can increase the resistance of plants to herbivorous insects. 2 As herbaceous plant endophytes are thought

ALAN C. GANGE; SOMA DEY; AMANDA F. CURRIE; BRIAN C. SUTTON

2007-01-01

383

INCREASED PLANT SIZE IN EXOTIC POPULATIONS: A COMMON-GARDEN TEST WITH 14 INVASIVE SPECIES  

Microsoft Academic Search

The ''evolution of increased competitive ability'' (EICA) hypothesis predicts that exotic species will adapt to reduced herbivore pressure by losing costly defenses in favor of competitive ability. Previous studies often support the prediction that plants from exotic populations will be less well defended than plants from native populations. However, results are mixed with respect to the question of whether plants

Dana M. Blumenthal; Ruth A. Hufbauer

2007-01-01

384

Observations on the measurement of total antimony and antimony species in algae, plant and animal tissuesw  

E-print Network

Observations on the measurement of total antimony and antimony species in algae, plant and animal of total antimony and antimony speciation in algae, plant and animal tissues. Digestion with nitric acid.g. some plants and algae, the addition of tetrafluorboric acid is required to dissolve silica as some

Canberra, University of

385

Collection and Domestication of Rangeland Plant Species with Emphasis on Mongolia and China  

Technology Transfer Automated Retrieval System (TEKTRAN)

Changing economic and social conditions are threatening plant diversity on rangelands in Mongolia and China. Teams of collaborating scientists from the U.S.A., Mongolia, and China collected seed of rangeland plant species in Mongolia and Inner Mongolia, China, to preserve plant biodiversity from th...

386

Species richness of both native and invasive aquatic plants influenced by environmental conditions and human activity  

Microsoft Academic Search

Invasive plants alter community structure, threatening ecosystem function and biodiversity, but little information is available on whether invasive species richness responds to environmental conditions in the same way that richness of native plants does. We surveyed submerged and floating-leaved plants in 99 Connecticut (northeast USA) lakes and ponds, collecting quantitative data on abundance and frequency. We used multiple linear and

Robert S. Capers; Roslyn Selsky; Gregory J. Bugbee; Jason C. White

2009-01-01

387

Uptake Kinetics of Arsenic Species in Rice Plants  

Microsoft Academic Search

Arsenic (As) finds its way into soils used for rice (Oryza sativa) cultivation through polluted irrigation water, and through historic contamination with As-based pesticides. As is known to be present as a number of chemical species in such soils, so we wished to investigate how these species were accumulated by rice. As species found in soil solution from a greenhouse

Mohammed Joinal Abedin; Jorg Feldmann; Andy A. Meharg

2002-01-01

388

Comparative pharmacognostic evaluation of some species of the genera Suaeda and Salsola leaf (Chenopodiaceae).  

PubMed

The genera Suaeda and Salsola are halophytic plants belong to the family Chenopodiaceae. Species of these genera have been extensively used in traditional medicines against many diseases due to their various bioactive compounds such as carotenoids, vitamins, sterol, phenolic compounds etc. The present research was carried out to establish detailed pharmacognosy of Suaeda fruticosa, Suaeda monoica, Salsola imbricata and Salsola tragus, which included macroscopy, microscopy, physico-chemical parameters and qualitative phytochemical screening of leaf samples extracted with methanol and chloroform. It was observed that macroscopic and microscopic characteristics were diagnostic features and can be used for distinction and identification of these closely related plant species. Phytochemically, these plant species are rich in constituents like anthraquinones, alkaloids, carbohydrates, cardiac glycosides, flavonoids, saponins, phenolic compounds and terpenoids. Physico-chemical parameters revealed that in all investigated plant species; methanol extractive values were higher than that of chloroform. Moreover, total ash values were found to be higher than other acid insoluble and water-soluble ash values, while a considerable amount of moisture was present in the species of both genera. On the basis of pharmacognosy, species of Suaeda were found to be more promising than Salsola. Present investigation will contribute towards establishment of pharmacognostic profile of these medicinally effective plants species. PMID:25176385

Munir, Uzma; Perveen, Anjum; Qamarunnisa, Syeda

2014-09-01

389

Alien Roadside Species More Easily Invade Alpine than Lowland Plant Communities in a Subarctic Mountain Ecosystem  

PubMed Central

Effects of roads on plant communities are not well known in cold-climate mountain ecosystems, where road building and development are expected to increase in future decades. Knowledge of the sensitivity of mountain plant communities to disturbance by roads is however important for future conservation purposes. We investigate the effects of roads on species richness and composition, including the plant strategies that are most affected, along three elevational gradients in a subarctic mountain ecosystem. We also examine whether mountain roads promote the introduction and invasion of alien plant species from the lowlands to the alpine zone. Observations of plant community composition were made together with abiotic, biotic and anthropogenic factors in 60 T-shaped transects. Alpine plant communities reacted differently to road disturbances than their lowland counterparts. On high elevations, the roadside species composition was more similar to that of the local natural communities. Less competitive and ruderal species were present at high compared with lower elevation roadsides. While the effects of roads thus seem to be mitigated in the alpine environment for plant species in general, mountain plant communities are more invasible than lowland communities. More precisely, relatively more alien species present in the roadside were found to invade into the surrounding natural community at high compared to low elevations. We conclude that effects of roads and introduction of alien species in lowlands cannot simply be extrapolated to the alpine and subarctic environment. PMID:24586947

Lembrechts, Jonas J.; Milbau, Ann; Nijs, Ivan

2014-01-01

390

Alien roadside species more easily invade alpine than lowland plant communities in a subarctic mountain ecosystem.  

PubMed

Effects of roads on plant communities are not well known in cold-climate mountain ecosystems, where road building and development are expected to increase in future decades. Knowledge of the sensitivity of mountain plant communities to disturbance by roads is however important for future conservation purposes. We investigate the effects of roads on species richness and composition, including the plant strategies that are most affected, along three elevational gradients in a subarctic mountain ecosystem. We also examine whether mountain roads promote the introduction and invasion of alien plant species from the lowlands to the alpine zone. Observations of plant community composition were made together with abiotic, biotic and anthropogenic factors in 60 T-shaped transects. Alpine plant communities reacted differently to road disturbances than their lowland counterparts. On high elevations, the roadside species composition was more similar to that of the local natural communities. Less competitive and ruderal species were present at high compared with lower elevation roadsides. While the effects of roads thus seem to be mitigated in the alpine environment for plant species in general, mountain plant communities are more invasible than lowland communities. More precisely, relatively more alien species present in the roadside were found to invade into the surrounding natural community at high compared to low elevations. We conclude that effects of roads and introduction of alien species in lowlands cannot simply be extrapolated to the alpine and subarctic environment. PMID:24586947

Lembrechts, Jonas J; Milbau, Ann; Nijs, Ivan

2014-01-01

391

Classification and identification of metal-accumulating plant species by cluster analysis.  

PubMed

Identification and classification of metal-accumulating plant species is essential for phytoextraction. Cluster analysis is used for classifying individuals based on measured characteristics. In this study, classification of plant species for metal accumulation was conducted using cluster analysis based on a practical survey. Forty plant samples belonging to 21 species were collected from an ancient silver-mining site. Five groups such as hyperaccumulator, potential hyperaccumulator, accumulator, potential accumulator, and normal accumulating plant were graded. For Cd accumulation, the ancient silver-mining ecotype of Sedum alfredii was treated as a Cd hyperaccumulator, and the others were normal Cd-accumulating plants. For Zn accumulation, S. alfredii was considered as a potential Zn hyperaccumulator, Conyza canadensis and Artemisia lavandulaefolia were Zn accumulators, and the others were normal Zn-accumulating plants. For Pb accumulation, S. alfredii and Elatostema lineolatum were potential Pb hyperaccumulators, Rubus hunanensis, Ajuga decumbens, and Erigeron annuus were Pb accumulators, C. canadensis and A. lavandulaefolia were potential Pb accumulators, and the others were normal Pb-accumulating plants. Plant species with the potential for phytoextraction were identified such as S. alfredii for Cd and Zn, C. canadensis and A. lavandulaefolia for Zn and Pb, and E. lineolatum, R. hunanensis, A. decumbens, and E. annuus for Pb. Cluster analysis is effective in the classification of plant species for metal accumulation and identification of potential species for phytoextraction. PMID:24888623

Yang, Wenhao; Li, He; Zhang, Taoxiang; Sen, Lin; Ni, Wuzhong

2014-09-01

392

BEYOND THE ECOLOGICAL: BIOLOGICAL INVASIONS ALTER NATURAL SELECTION ON A NATIVE PLANT SPECIES  

Microsoft Academic Search

Biological invasions can have strong ecological effects on native communities by altering ecosystem functions, species interactions, and community composition. Even though these ecological effects frequently impact the population dynamics and fitness of native species, the evolutionary consequences of biological invasions have received relatively little attention. Here, I show that invasions impose novel selective pressures on a native plant species. By

Jennifer A. Lau

2008-01-01

393

Phytochemicals of selected plant species of the Apocynaceae and Asclepiadaceae from Western Ghats, Tamil Nadu, India  

Technology Transfer Automated Retrieval System (TEKTRAN)

A concern about the declining supply of petroleum products has led to a renewed interest in evaluating plant species as potential alternate sources of energy. Five species of the Apocynaceae and three species of the Asclepiadaceae from the Western Ghats were evaluated as alternative sources of energ...

394

Resource-based niches provide a basis for plant species diversity and dominance in arctic tundra  

Microsoft Academic Search

Ecologists have long been intrigued by the ways co-occurring species divide limiting resources. Such resource partitioning, or niche differentiation, may promote species diversity by reducing competition. Although resource partitioning is an important determinant of species diversity and composition in animal communities, its importance in structuring plant communities has been difficult to resolve. This is due mainly to difficulties in studying

Robert B. McKane; Loretta C. Johnson; Gaius R. Shaver; Knute J. Nadelhoffer; Edward B. Rastetter; Brian Fry; Anne E. Giblin; Knut Kielland; Bonnie L. Kwiatkowski; James A. Laundre; Georgia Murray

2002-01-01

395

The Main Environmental Driving Forces of the Invasive Plant Species in the Romanian Protected Areas  

Microsoft Academic Search

The invasive flora of Romania currently includes more than 400 species (13.87% of the Romanian flora) and according to the third National Report of Biological Diversity Convention, six of them are tree species. Within the protected areas, some of the most representative invasive plant species (IPS) are: Amorpha fruticosa in Balta Mica a Brailei National Park, Ailanthus altissima in Muntii

Monica Dumitrascu; Ines Grigorescu; Mihaela Nastase; Carmen Dragota; Gheorghe Kucsicsa

2010-01-01

396

Effect of Carpobrotus spp. on the pollination success of native plant species of the Balearic Islands  

Microsoft Academic Search

Invasive plant species are often considered as potential competitors of native species due to their usually greater capacity for colonization and expansion, but we still have scarce information on whether invasives can also compete for pollination services with natives. In the present study, we hypothesized that the showy flowers of the highly invasive Carpobrotu spp. can compete with native species

Eva Moragues; Anna Traveset

2005-01-01

397

Controls on pathogen species richness in plants introduced and native ranges: roles of residence  

E-print Network

LETTER Controls on pathogen species richness in plantsÃ? introduced and native ranges: roles,4 Emily E. Puckett1 and Petr Pysek3,4 Abstract Introduced species escape many pathogens and other enemies, raising three questions. How quickly do introduced hosts accumulate pathogen species? What factors control

Kratochvíl, Lukas

398

Trait-Based Filtering of the Regional Species Pool to Guide Understory Plant Reintroductions  

E-print Network

that regenerate vegetatively may outperform other species when introduced to restored sites (Pywell et al. 2003Trait-Based Filtering of the Regional Species Pool to Guide Understory Plant Reintroductions during ecological restoration is rees- tablishing the local species pool through active reintroduc- tion

399

Plant uptake and determination of arsenic species in soil solution under flooded conditions  

Microsoft Academic Search

Previous studies have not identified the different As species present in soil systems and determined if effective differences exist between As species with respect to plant parameters such as growth rate and As uptake. This study determined the species and concentrations of As present in soil solution of flooded soils and correlated them to As concentration, P concentration, an growth

B. M. Onken; L. R. Hossner

1995-01-01

400

Big plants — Do they affect neighbourhood species richness and composition in herbaceous vegetation?  

NASA Astrophysics Data System (ADS)

According to traditional theory, success in competition between plant species generally involves a 'size-advantage'. We predicted therefore that plants with larger body size should impose greater limits on the number of species — especially relatively small ones — that can reside within their immediate neighbourhoods. Species composition was compared within local neighbourhoods surrounding target plants of different sizes belonging to one of the largest herbaceous species found within old-field vegetation in eastern Ontario Canada — Centaurea jacea. Resident species density was generally greater within immediate 'inner' target neighbourhoods than within adjacent circular 'outer' neighbourhoods, and mean body size of resident neighbour species was unrelated to increases in target plant size. As target plant size increased, the proportion of resident neighbour species that were reproductive increased. Relatively big plants of C. jacea do not limit the number or the proportion of reproductive species that can coexist within their immediate neighbourhoods, nor do they cause local exclusion of relatively small species from these neighbourhoods. These results fail to support the 'size-advantage' hypothesis and are more consistent with the 'reproductive economy advantage' hypothesis: success under intense competition is promoted by capacity to recruit offspring that — despite severe suppression — are able to reach their minimum body size needed for reproduction, and hence produce grand-offspring for the next generation. The latter is facilitated by a relatively small minimum reproductive threshold size, which is generally negatively correlated with a relatively large maximum potential body size.

Aarssen, Lonnie W.; Schamp, Brandon S.; Wight, Stephanie

2014-02-01

401

Developing transgenic Jatropha using the SbNHX1 gene from an extreme halophyte for cultivation in saline wasteland.  

PubMed

Jatropha is an important second-generation biofuel plant. Salinity is a major factor adversely impacting the growth and yield of several plants including Jatropha. SbNHX1 is a vacuolar Na?/H? antiporter gene that compartmentalises excess Na? ions into the vacuole and maintains ion homeostasis. We have previously cloned and characterised the SbNHX1 gene from an extreme halophyte, Salicornia brachiata. Transgenic plants of Jatropha curcas with the SbNHX1 gene were developed using microprojectile bombardment mediated transformation. Integration of the transgene was confirmed by PCR and Rt-PCR and the copy number was determined by real time qPCR. The present study of engineering salt tolerance in Jatropha is the first report to date. Salt tolerance of the transgenic lines JL2, JL8 and JL19 was confirmed by leaf senescence assay, chlorophyll estimation, plant growth, ion content, electrolyte leakage and malondialdehyde (MDA) content analysis. Transgenic lines showed better salt tolerance than WT up to 200 mM NaCl. Imparting salt tolerance to Jatropha using the SbNHX1 gene may open up the possibility of cultivating it in marginal salty land, releasing arable land presently under Jatropha cultivation for agriculture purposes. Apart from this, transgenic Jatropha can be cultivated with brackish water, opening up the possibility of sustainable cultivation of this biofuel plant in salty coastal areas. PMID:23940703

Joshi, Mukul; Jha, Anupama; Mishra, Avinash; Jha, Bhavanath

2013-01-01

402

Carbon partitioning in a split-root system of arbuscular mycorrhizal plants is fungal and plant species dependent  

Microsoft Academic Search

Summary • Root carbon (C) partitioning in two host plant species colonized by one of three arbuscular mycorrhizal (AM) fungal species was investigated. • Split-root systems of barley ( Hordeum vulgare ) and sugar maple ( Acer saccharum ) were inoculated on one side with one of three AM fungi. Leaves were labelled with 14 CO 2 3 wk after

Sylvain Lerat; Line Lapointe; Sylvain Gutjahr; Yves Piche; Horst Vierheilig

2003-01-01

403

Effects of invasive species on plant communities: an example using submersed aquatic plants at the regional scale  

Microsoft Academic Search

Submersed aquatic plants have a key role in maintaining functioning aquatic ecosystems through their effects on the hydrological\\u000a regime, sedimentation, nutrient cycling and habitat of associated fauna. Modifications of aquatic plant communities, for example\\u000a through the introduction of invasive species, can alter these functions. In the Sacramento-San Joaquin River Delta, California,\\u000a a major invasive submersed plant, Brazilian waterweed Egeria densa,

Maria J. SantosLars; Lars W. Anderson; Susan L. Ustin

2011-01-01

404

Arbuscular mycorrhizal fungi reduce the differences in competitiveness between dominant and subordinate plant species.  

PubMed

In grassland communities, plants can be classified as dominants or subordinates according to their relative abundances, but the factors controlling such distributions remain unclear. Here, we test whether the presence of the arbuscular mycorrhizal (AM) fungus Glomus intraradices affects the competitiveness of two dominant (Taraxacum officinale and Agrostis capillaris) and two subordinate species (Prunella vulgaris and Achillea millefolium). Plants were grown in pots in the presence or absence of the fungus, in monoculture and in mixtures of both species groups with two and four species. In the absence of G. intraradices, dominants were clearly more competitive than subordinates. In inoculated pots, the fungus acted towards the parasitic end of the mutualism-parasitism continuum and had an overall negative effect on the growth of the plant species. However, the negative effects of the AM fungus were more pronounced on dominant species reducing the differences in competitiveness between dominant and subordinate species. The effects of G. intraradices varied with species composition highlighting the importance of plant community to mediate the effects of AM fungi. Dominant species were negatively affected from the AM fungus in mixtures, while subordinates grew identically with and without the fungus. Therefore, our findings predict that the plant dominance hierarchy may flatten out when dominant species are more reduced than subordinate species in an unfavourable AM fungal relationship (parasitism). PMID:23064770

Mariotte, Pierre; Meugnier, Claire; Johnson, David; Thébault, Aurélie; Spiegelberger, Thomas; Buttler, Alexandre

2013-05-01

405

Regional climate model downscaling may improve the prediction of alien plant species distributions  

NASA Astrophysics Data System (ADS)

Distributions of invasive species are commonly predicted with species distribution models that build upon the statistical relationships between observed species presence data and climate data. We used field observations, climate station data, and Maximum Entropy species distribution models for 13 invasive plant species in the United States, and then compared the models with inputs from a General Circulation Model (hereafter GCM-based models) and a downscaled Regional Climate Model (hereafter, RCM-based models).We also compared species distributions based on either GCM-based or RCM-based models for the present (1990-1999) to the future (2046-2055). RCM-based species distribution models replicated observed distributions remarkably better than GCM-based models for all invasive species under the current climate. This was shown for the presence locations of the species, and by using four common statistical metrics to compare modeled distributions. For two widespread invasive taxa ( Bromus tectorum or cheatgrass, and Tamarix spp. or tamarisk), GCM-based models failed miserably to reproduce observed species distributions. In contrast, RCM-based species distribution models closely matched observations. Future species distributions may be significantly affected by using GCM-based inputs. Because invasive plants species often show high resilience and low rates of local extinction, RCM-based species distribution models may perform better than GCM-based species distribution models for planning containment programs for invasive species.

Liu, Shuyan; Liang, Xin-Zhong; Gao, Wei; Stohlgren, Thomas J.

2014-12-01

406

Sodium instead of potassium and chloride is an important macronutrient to improve leaf succulence and shoot development for halophyte Sesuvium portulacastrum.  

PubMed

Soil salinity is contributed largely by NaCl but some halophytes such as Sesuvium portulacastrum have evolved to adapt salinity environment and demonstrate optimal development under moderate salinity. To elucidate the detail mechanisms of the great salt tolerance and determine the respective contributions of Na(+), K(+) and Cl(-) on the development of S. portulacastrum, morphological and physiological analysis were performed using plants supplied with 200 mM of different ions including cations (Na(+), K(+), Li(+)) and anions (Cl(-), NO(3)(-), Ac(-)) respectively. The results revealed that the salt-treated plants accumulated large amounts of sodium in both leaf and stem. There was a greater shoot growth in presence of external Na(+) compared to K(+) and Cl(-). Na(+) was found more effective than K(+) and Cl(-) in cell expansion, leaf succulence, and shoot development. Flame emission and X-Ray microanalysis revealed the relative Na(+) content was much higher than K(+) and Cl(-) in both leaf and stem of well developed S. portulacastrum, leading to a higher Na(+)/K(+) ratio. The effects of different ions on the development of S. portulacastrum were listed as the following: Na(+) > NO(3)(-) > CK > Cl(-) > K(+) > Ac(-) > Li(+). These results demonstrated NaCl toxicity is attributable largely to the effect of Cl(-) but rarely to Na(+), and thus sodium is concluded as a more important macronutrient than potassium and chloride for improving leaf succulence and shoot development of halophyte S. portulacastrum. PMID:22153240

Wang, Dongyang; Wang, Haiyan; Han, Bing; Wang, Bin; Guo, Anping; Zheng, Dong; Liu, Chongjing; Chang, Lili; Peng, Ming; Wang, Xuchu

2012-02-01

407

Metabolomics: creating new potentials for unraveling the mechanisms in response to salt and drought stress and for the biotechnological improvement of xero-halophytes.  

PubMed

Breeders have long been interested in understanding the biological function and mechanism of xero-halophytes and their ability for growth in drought-stricken and salinized environments. However, the mechanisms in response to stress have been difficult to unravel because their defenses require regulatory changes to the activation of multiple genes and pathways. Metabolomics is becoming a key tool in comprehensively understanding the cellular response to abiotic stress and represents an important addition to the tools currently employed in genomics-assisted selection for plant improvement. In this review, we highlight the applications of plant metabolomics in characterizing metabolic responses to salt and drought stress, and identifying metabolic quantitative trait loci (QTLs). We also discuss the potential of metabolomics as a tool to unravel stress response mechanisms, and as a viable option for the biotechnological improvement of xero-halophytes when no other genetic information such as linkage maps and QTLs are available, by combining with germplasm-regression-combined marker-trait association identification. PMID:21058928

Ruan, Cheng-Jiang; Teixeira da Silva, Jaime A

2011-06-01

408

Cattle grazing increases plant species richness of most species trait groups in mesic semi-natural grasslands  

Microsoft Academic Search

The effects of cattle grazing on plant species trait groups were studied by comparing three kinds of mesic seminatural grasslands in southern Finland: old (continuously cattle grazed), new (cattle grazing restarted 3–8 years ago) and abandoned pastures (grazing terminated > 10 years ago). Two spatial scales were studied: 1 m2 and grassland patch (0.25–0.8 ha). Species richness was higher among

Juha Pykälä

2005-01-01

409

Postglacial migration supplements climate in determining plant species ranges in Europe  

PubMed Central

The influence of dispersal limitation on species ranges remains controversial. Considering the dramatic impacts of the last glaciation in Europe, species might not have tracked climate changes through time and, as a consequence, their present-day ranges might be in disequilibrium with current climate. For 1016 European plant species, we assessed the relative importance of current climate and limited postglacial migration in determining species ranges using regression modelling and explanatory variables representing climate, and a novel species-specific hind-casting-based measure of accessibility to postglacial colonization. Climate was important for all species, while postglacial colonization also constrained the ranges of more than 50 per cent of the species. On average, climate explained five times more variation in species ranges than accessibility, but accessibility was the strongest determinant for one-sixth of the species. Accessibility was particularly important for species with limited long-distance dispersal ability, with southern glacial ranges, seed plants compared with ferns, and small-range species in southern Europe. In addition, accessibility explained one-third of the variation in species' disequilibrium with climate as measured by the realized/potential range size ratio computed with niche modelling. In conclusion, we show that although climate is the dominant broad-scale determinant of European plant species ranges, constrained dispersal plays an important supplementary role. PMID:21543356

Normand, Signe; Ricklefs, Robert E.; Skov, Flemming; Bladt, Jesper; Tackenberg, Oliver; Svenning, Jens-Christian

2011-01-01

410

Postglacial migration supplements climate in determining plant species ranges in Europe.  

PubMed

The influence of dispersal limitation on species ranges remains controversial. Considering the dramatic impacts of the last glaciation in Europe, species might not have tracked climate changes through time and, as a consequence, their present-day ranges might be in disequilibrium with current climate. For 1016 European plant species, we assessed the relative importance of current climate and limited postglacial migration in determining species ranges using regression modelling and explanatory variables representing climate, and a novel species-specific hind-casting-based measure of accessibility to postglacial colonization. Climate was important for all species, while postglacial colonization also constrained the ranges of more than 50 per cent of the species. On average, climate explained five times more variation in species ranges than accessibility, but accessibility was the strongest determinant for one-sixth of the species. Accessibility was particularly important for species with limited long-distance dispersal ability, with southern glacial ranges, seed plants compared with ferns, and small-range species in southern Europe. In addition, accessibility explained one-third of the variation in species' disequilibrium with climate as measured by the realized/potential range size ratio computed with niche modelling. In conclusion, we show that although climate is the dominant broad-scale determinant of European plant species ranges, constrained dispersal plays an important supplementary role. PMID:21543356

Normand, Signe; Ricklefs, Robert E; Skov, Flemming; Bladt, Jesper; Tackenberg, Oliver; Svenning, Jens-Christian

2011-12-22

411

Plant translational genomics: from model species to crops  

Microsoft Academic Search

Plant genomic research now faces the ultimate challenge to develop applications in crop plants which implies the translation\\u000a of gene functions from a model to a crop which is the field of ‘Plant translational genomics’. In this paper we discuss the\\u000a perspectives of the candidate gene approach (CGA) as a tool for translational genomics in the ‘whole genome’ era. Factors

Elma M. J. Salentijn; Andy Pereira; Gerco C. Angenent; C. Gerard van der Linden; Frans Krens; Marinus J. M. Smulders; Ben Vosman

2007-01-01

412

Use of plant woody species electrical potential for irrigation scheduling.  

PubMed

The electrical response of plants to environmental stimuli can be measured and quantitatively related to the intensity of several stimulating sources, like temperature, solar radiation, soil water content, evapotranspiration rates, sap flow and dendrometric cycles. These relations can be used to assess the influence of different environmental situations on soil water availability to plants, defined as a steady state condition between leaf transpirative flow and soil water flow to plant roots. A restricted soil water flow due to soil dryness can trigger water stress in plants, if the atmospheric evaporative demand is high, causing partial stomata closure as a physiological response to avoid plant dehydration; water stressed and unstressed plants manifest a differential electrical response. Real time plant electrical response measurements can anticipate actions that prevent the plant reaching actual stress conditions, optimizing stomata gas exchange and photosynthetic rates. An electrophysiological sensor developed in this work, allows remote real-time recording information on plant electrical potential (EP) in the field, which is highly related to EP measurements obtained with a laboratory Keithley voltmeter sensor used in an highly controlled experimental setup. Our electrophysiological sensor is a wireless, autonomous devise, which transmits EP information via Internet to a data server. Using both types of sensors (EP electrodes with a Keithley voltmeter and the electrophysiological sensor), we measured in real time the electrical responses of Persea americana and Prunus domestica plants, to induced water deficits. The differential response for 2 scenarios: irrigation and water restriction is identified by a progressive change in slope on the daily maximal and minimal electric signal values in stressed plants, and a zero-slope for similar signals for well-watered plants. Results show a correspondence between measured signals obtained by our electrophysiological sensor and the EP electrodes connected to the Keithley voltmeter in each irrigation stage. Also, both sensors show a daily cyclical signal (circadian cycle). PMID:25826257

Ríos-Rojas, Liliana; Morales-Moraga, David; Alcalde, José A; Gurovich, Luis A

2015-02-01

413

Individual Species-Area Relationship of Woody Plant Communities in a Heterogeneous Subtropical Monsoon Rainforest  

PubMed Central

The spatial structure of species richness is often characterized by the species-area relationship (SAR). However, the SAR approach rarely considers the spatial variability of individual plants that arises from species interactions and species’ habitat associations. Here, we explored how the interactions of individual plants of target species influence SAR patterns at a range of neighborhood distances. We analyzed the data of 113,988 woody plants of 110 species from the Fushan Forest Dynamics Plot (25 ha), northern Taiwan, which is a subtropical rainforest heavily influenced by typhoons. We classified 34 dominant species into 3 species types (i.e., accumulator, repeller, or no effect) by testing how the individual species-area relationship (i.e., statistics describing how neighborhood species richness changes around individuals) of target species departs (i.e., positively, negatively, or with no obvious trend) from a null model that accounts for habitat association. Deviation from the null model suggests that the net effect of species’ interactions increases (accumulate) or decreases (repel) neighborhood species richness. We found that (i) accumulators were dominant at small interaction distances (<10–30 m); (ii) the detection of accumulator species was lower at large interaction distances (>30 m); (iii) repellers were rarely detected; and (iv) large-sized and abundant species tended to be accumulators. The findings suggest that positive species interactions have the potential to accumulate neighborhood species richness, particularly through size- and density-dependent mechanisms. We hypothesized that the frequently disturbed environment of this subtropical rainforest (e.g., typhoon-driven natural disturbances such as landslides, soil erosion, flooding, and windthrow) might create the spatial heterogeneity of species richness and promote positive species interactions. PMID:25884405

Tsai, Cheng-Han; Lin, Yi-Ching; Wiegand, Thorsten; Nakazawa, Takefumi; Su, Sheng-Hsin

2015-01-01

414

A comparative study of AMF diversity in annual and perennial plant species from semiarid gypsum soils.  

NASA Astrophysics Data System (ADS)

The arbuscular mycorrhizal fungi (AMF) communities composition regulate plant interactions and determine the structure of plant communities. In this study we analysed the diversity of AMF in the roots of two perennial gypsophyte plant species, Herniaria fruticosa and Senecio auricula, and an annual herbaceous species, Bromus rubens, growing in a gypsum soil from a semiarid area. The objective was to determine whether perennial and annual host plants support different AMF communities in their roots and whether there are AMF species that might be indicators of specific functional plant roles in these ecosystems. The roots were analysed by nested PCR, cloning, sequencing of the ribosomal DNA small subunit region and phylogenetic analysis. Twenty AMF sequence types, belonging to the Glomus group A, Glomus group B, Diversisporaceae, Acaulosporaceae, Archaeosporaceae and Paraglomeraceae, were identified. Both gypsophyte perennial species had differing compositions of the AMF community and higher diversity when compared with the annual species, showing preferential selection by specific AMF sequences types. B. rubens did not show host specificity, sharing the full composition of its AMF community with both perennial plant species. Seasonal variations in the competitiveness of AM fungi could explain the observed differences in AMF community composition, but this is still a working hypothesis that requires the analysis of further data obtained from a higher number of both annual and perennial plant species in order to be fully tested.

Alguacil, M. M.; Torrecillas, E.; Roldán, A.; Díaz, G.; Torres, P.

2012-04-01

415

Methods of propagation for selected native Texas woody plant species  

E-print Network

of the plant to be used. For example, Redbuds from Tennessee cannot be expected to flower as well in central Texas as do hill country Redbuds. Likewise, Bald Cypresses from east Texas may not do as well along central Texas river- ways or in other plantings... as do trees grown from the seed of the local Bald Cypress. To develop this concept of appropriate habitat further, the niche or preferred site of each plant should be under- stood. Often the fact that a plant is native means to many people tl...

Senior, Jill Ellen

1976-01-01

416

Photosynthetic light response in three carnivorous plant species: Drosera rotundifolia, D. capensis and Sarracenia leucophylla  

Microsoft Academic Search

Photosynthetic properties of carnivorous plants have not been well characterized and the extent to which photosynthesis contributes\\u000a to carbon gain in most carnivorous plants is also largely unknown. We investigated the photosynthetic light response in three\\u000a carnivorous plant species, Drosera rotundifolia L. (sundew; circumpolar and native to northern British Columbia, Canada), Sarracenia leucophylla Rafin. (‘pitcher-plant’; S.E. United States), and D.

B. M. Bruzzese; R. Bowler; H. B. Massicotte; A. L. Fredeen

2010-01-01

417

Species-Specific Responses to Community Density in an Unproductive Perennial Plant Community  

PubMed Central

Most studies of density dependent regulation in plants consider a single target species, but regulation may also occur at the level of the entire community. Knowing whether a community is at carrying capacity is essential for understanding its behaviour because low density plant communities may behave quite differently than their high density counterparts. Also, because the intensity of density dependence may differ considerably between species and physical environments, generalizations about its effects on community structure requires comparisons under a range of conditions. We tested if: (1) density dependent regulation occurs at the level of an entire plant community as well as within individual species; (2) the intensity (effect of increasing community density on mean plant mass) and importance (the effect of increasing density, relative to other factors, on mean plant mass) of competition increases, decreases or remains unchanged with increasing fertilization; (3) there are species-specific responses to changes in community density and productivity. In 63 1 m2 plots, we manipulated the abundance of the nine most common species by transplanting or removing them to create a series of Initial Community Densities above and below the average natural field density, such that the relative proportion of species was consistent for all densities. Plots were randomly assigned to one of three fertilizer levels. At the community level, negative density dependence of mean plant size was observed for each of the 4 years of the study and both the intensity and importance of competition increased each year. At the species level, most species' mean plant mass were negatively density dependent. Fertilizer had a significant effect only in the final year when it had a negative effect on mean plant mass. Our data demonstrate a yield-density response at the entire community-level using perennial plant species in a multi-year experiment. PMID:25050710

Treberg, Michael A.; Turkington, Roy

2014-01-01

418

Invasive plants have scale-dependent effects on diversity by altering species-area relationships.  

PubMed

Although invasive plant species often reduce diversity, they rarely cause plant extinctions. We surveyed paired invaded and uninvaded plant communities from three biomes. We reconcile the discrepancy in diversity loss from invaders by showing that invaded communities have lower local richness but steeper species accumulation with area than that of uninvaded communities, leading to proportionately fewer species loss at broader spatial scales. We show that invaders drive scale-dependent biodiversity loss through strong neutral sampling effects on the number of individuals in a community. We also show that nonneutral species extirpations are due to a proportionately larger effect of invaders on common species, suggesting that rare species are buffered against extinction. Our study provides a synthetic perspective on the threat of invasions to biodiversity loss across spatial scales. PMID:23329045

Powell, Kristin I; Chase, Jonathan M; Knight, Tiffany M

2013-01-18

419

Active Oxygen Species in Plant Defense against Pathogens  

Microsoft Academic Search

Plant disease resistance to pathogens such as fungi, bac- teria, and viruses often depends on whether the plant is able to recognize the pathogen early in the infection process. The recognition event leads to a rapid tissue necrosis at the site of infection, which is called the HR. The HR deprives the pathogen of nutrients and\\/or releases toxic molecules, thereby

Mona C. Mehdy

1993-01-01

420

Plant coexistence alters terpene emission and content of Mediterranean species  

Microsoft Academic Search

There is evidence that secondary metabolism may modulate plant interactions and is modified by different biotic stress agents, such as herbivores or pathogens. However, it is poorly understood whether secondary metabolism is altered during competition among plants. The intraspecific and interspecific coexistence of some Mediterranean potted seedlings, namely Rosmarinus officinalis, Pinus halepensis, Cistus albidus and Quercus coccifera was investigated through

Elena Ormeño; Catherine Fernandez; Jean-Philippe Mévy

2007-01-01