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1

Ultrastructural studies on the natural leaf senescence of Cinnamomum camphora.  

PubMed

The process of natural leaf senescence of Cinnamomum camphora (C. camphora)-a commercial tree in Asia, was investigated, focusing on changes in cellular ultrastructure, epicuticular wax, and stoma. The changes to mesophyll cells in a senescing leaf predominantly include degradation of the following cellular components: cytoplasm, the central vacuole, small vacuoles, and vesicles with a diameter smaller than 400 nm, which are involved in the degradation of chloroplasts. The sequence of change in epicuticular wax during leaf senescence was different from those in herbaceous plants by atomic force microscope and scanning electron microscopic analysis. Comparing with maturation leaves, senescing leaves develop a wider aperture in their stoma, which would delay the leaf senescence of C. camphora. PMID:23292543

Cao, Jianbo; Song, Yantun; Wu, Hua; Qin, Lihong; Hu, Lihua; Hao, Rong

2013-01-01

2

In vitro anti-inflammatory and anti-oxidative effects of Cinnamomum camphora extracts  

Microsoft Academic Search

Cinnamomum camphora Sieb (Lauraceae) has long been prescribed in traditional medicine for the treatment of inflammation-related diseases such as rheumatism, sprains, bronchitis and muscle pains. In this study, therefore, we aimed to investigate the inhibitory effects of Cinnamomum camphora on various inflammatory phenomena to explore its potential anti-inflammatory mechanisms under non-cytotoxic (less than 100?g\\/ml) conditions. The total crude extract (100?g\\/ml)

Hye Ja Lee; Eun-A Hyun; Weon Jong Yoon; Byung Hun Kim; Man Hee Rhee; Hee Kyoung Kang; Jae Youl Cho; Eun Sook Yoo

2006-01-01

3

[Transcriptome analysis for leaves of five chemical types in Cinnamomum camphora].  

PubMed

Camphor tree (Cinnamomum camphora) is a representative species in Lauraceae family, and can be subdivided into five types: linalool, camphor, cineol, iso-nerolidol and borneol. In this paper, the leaves transcriptomes of Cinnamomum camphora were sequenced with the platform of Illumina HiSeq™ 2000. Based on the GO (Gene Ontology), COG (Clusters of Orthologous Groups), and KEGG (Kyoto Encyclopedia of Genes and Genomes) database, the function classification, pathway annotation, and the coding sequence prediction of all-Unigenes were carried out. 156 278 Unigenes with an average length of 584 bp and N50 (N50 value is defined as the Unigene length where half the assembly is represented by Unigenes of this size or longer) of 1 023 bp were generated by de novo assembly. A total of 5 5955 Unigenes (35.80%) were annotated through similarity comparison, in which 24 717 and 21 806 Unigenes were assigned into GO and COG, respectively. By searching KEGG database, 3 350 Unigenes were involved in biosynthesis of secondary metabolites, in which 424 Unigenes were involved in monoterpenoids, diterpenoids, sesquiterpenoids, and terpenoid backbone biosynthesis. The analysis of monoterpenoids biosynthesis pathway showed that 9 Unigenes likely encode (+)-linalool synthase, and their expression levels were higher in linalool type but lower in cineole type. This study provides a foundation for further characterizing the functional genes in C. camphora. PMID:24846919

Jiang, Xiangmei; Wu, Yanfang; Xiao, Fuming; Xiong, Zhenyu; Xu, Haining

2014-01-01

4

Non-Stomatal Limitation to Photosynthesis in Cinnamomum camphora Seedings Exposed to Elevated O3  

PubMed Central

Ozone (O3) is the most phytotoxic air pollutant for global forests, with decreased photosynthesis widely regarded as one of its most common effects. However, controversy exists concerning the mechanism that underlies the depressing effects of O3 on CO2 assimilation. In the present study, seedlings of Cinnamomum camphora, a subtropical evergreen tree species that has rarely been studied, were exposed to ambient air (AA), ambient air plus 60 [ppb] O3 (AA+60), or ambient air plus 120 [ppb] O3 (AA+120) in open-top chambers (OTCs) for 2 years. Photosynthetic CO2 exchange and chlorophyll a fluorescence were investigated in the second growing season (2010). We aim to determine whether stomatal or non-stomatal limitation is responsible for the photosynthesis reduction and to explore the potential implications for forest ecosystem functions. Results indicate that elevated O3 (E-O3) reduced the net photosynthetic rates (PN) by 6.0-32.2%, with significant differences between AA+60 and AA+120 and across the four measurement campaigns (MCs). The actual photochemical efficiency of photosystem II (PSII) in saturated light (Fv?/Fm?) was also significantly decreased by E-O3, as was the effective quantum yield of PSII photochemistry (?PSII). Moreover, E-O3 significantly and negatively impacted the maximum rates of carboxylation (Vcmax) and electron transport (Jmax). Although neither the stomatal conductance (gs) nor the intercellular CO2 concentration (Ci) was decreased by E-O3, PN/gs was significantly reduced. Therefore, the observed reduction in PN in the present study should not be attributed to the unavailability of CO2 due to stomatal limitation, but rather to the O3-induced damage to Ribulose-1,5-bisphosphate carboxylase/oxygenase and the photochemical apparatus. This suggests that the down-regulation of stomatal conductance could fail to occur, and the biochemical processes in protoplasts would become more susceptible to injuries under long-term O3 exposure, which may have important consequences for forest carbon and water budget.

Niu, Junfeng; Feng, Zhaozhong; Zhang, Weiwei; Zhao, Ping; Wang, Xiaoke

2014-01-01

5

Non-Stomatal Limitation to Photosynthesis in Cinnamomum camphora Seedings Exposed to Elevated O3.  

PubMed

Ozone (O3) is the most phytotoxic air pollutant for global forests, with decreased photosynthesis widely regarded as one of its most common effects. However, controversy exists concerning the mechanism that underlies the depressing effects of O3 on CO2 assimilation. In the present study, seedlings of Cinnamomum camphora, a subtropical evergreen tree species that has rarely been studied, were exposed to ambient air (AA), ambient air plus 60 [ppb] O3 (AA+60), or ambient air plus 120 [ppb] O3 (AA+120) in open-top chambers (OTCs) for 2 years. Photosynthetic CO2 exchange and chlorophyll a fluorescence were investigated in the second growing season (2010). We aim to determine whether stomatal or non-stomatal limitation is responsible for the photosynthesis reduction and to explore the potential implications for forest ecosystem functions. Results indicate that elevated O3 (E-O3) reduced the net photosynthetic rates (PN) by 6.0-32.2%, with significant differences between AA+60 and AA+120 and across the four measurement campaigns (MCs). The actual photochemical efficiency of photosystem II (PSII) in saturated light (Fv'/Fm') was also significantly decreased by E-O3, as was the effective quantum yield of PSII photochemistry (?PSII). Moreover, E-O3 significantly and negatively impacted the maximum rates of carboxylation (Vcmax) and electron transport (Jmax). Although neither the stomatal conductance (gs) nor the intercellular CO2 concentration (Ci) was decreased by E-O3, PN/gs was significantly reduced. Therefore, the observed reduction in PN in the present study should not be attributed to the unavailability of CO2 due to stomatal limitation, but rather to the O3-induced damage to Ribulose-1,5-bisphosphate carboxylase/oxygenase and the photochemical apparatus. This suggests that the down-regulation of stomatal conductance could fail to occur, and the biochemical processes in protoplasts would become more susceptible to injuries under long-term O3 exposure, which may have important consequences for forest carbon and water budget. PMID:24892748

Niu, Junfeng; Feng, Zhaozhong; Zhang, Weiwei; Zhao, Ping; Wang, Xiaoke

2014-01-01

6

Biosynthesis of silver and gold nanoparticles by novel sundried Cinnamomum camphora leaf  

NASA Astrophysics Data System (ADS)

The synthesis of nanocrystals is in the limelight in modern nanotechnology. Biosynthesis of nanoparticles by plant extracts is currently under exploitation. Not only could silver nanoparticles ranging from 55 to 80 nm in size be fabricated, but also triangular or spherical shaped gold nanoparticles could be easily modulated by reacting the novel sundried biomass of Cinnamomum camphora leaf with aqueous silver or gold precursors at ambient temperature. The marked difference of shape control between gold and silver nanoparticles was attributed to the comparative advantage of protective biomolecules and reductive biomolecules. The polyol components and the water-soluble heterocyclic components were mainly responsible for the reduction of silver ions or chloroaurate ions and the stabilization of the nanoparticles, respectively. The sundried leaf in this work was very suitable for simple synthesis of nanoparticles.

Huang, Jiale; Li, Qingbiao; Sun, Daohua; Lu, Yinghua; Su, Yuanbo; Yang, Xin; Wang, Huixuan; Wang, Yuanpeng; Shao, Wenyao; He, Ning; Hong, Jinqing; Chen, Cuixue

2007-03-01

7

Bioactivities and compositional analyses of Cinnamomum essential oils from Nepal: C. camphora, C. tamala, and C. glaucescens.  

PubMed

This work examines the biological activity of essential oils of Cinnamomum camphora leaves, C. glaucescens fruit, and C. tamala root from Nepal. The oils were screened for phytotoxic activity against lettuce and perennial ryegrass, brine shrimp lethality, and antibacterial, antifungal, cytotoxic, insecticidal, and nematicidal activities. C. camphora leaf essential oil was phytotoxic to lettuce, antifungal to Aspergillus niger, and insecticidal, particularly toward midge and butterfly larvae, fruit flies, and fire ants. C. camphora oil was also toxic to brine shrimp and human breast tumor cells. C. glaucescens fruit essential oil showed notable nematicidal activity, as well as termiticidal and mosquito larvicidal activity. The root essential oil of C. tamala was toxic to mosquito larvae and fire ants. PMID:24555298

Satyal, Prabodh; Paudel, Prajwal; Poudel, Ambika; Dosoky, Noura S; Pokharel, Kiran Kumar; Setzer, William N

2013-12-01

8

Fungal contamination of raw materials of some herbal drugs and recommendation of Cinnamomum camphora oil as herbal fungitoxicant.  

PubMed

The paper explores fungal infection and aflatoxin B1 contamination of six medicinal plant samples viz. Adhatoda vasica Nees, Asparagus racemosus Linn., Evolvulus alsinoides Linn., Glycyrrhiza glabra Linn., Plumbago zeylanica Linn. and Terminalia chebula Retz. A total of 858 fungal isolates were detected from the raw materials. Maximum number of fungal isolates was detected from A. racemosus (228). The genus Aspergillus was found to be the most dominant genus causing infection to most of the raw materials. Among the 32 isolates of A. flavus tested, 13 isolates were found to be toxigenic elaborating aflatoxin B1. The highest elaboration of aflatoxin B1 was 394.95 ppb by the isolates of A. flavus from G. glabra. The essential oil of Cinnamomum camphora (L.) Presl showed efficacy in arresting aflatoxin B1 by the toxigenic strain. The growth of a toxigenic strain of A. flavus decreased progressively with increasing concentration of essential oil from leaves of C. camphora. The oil completely inhibited aflatoxin B1 production even at 750 ppm. Hence, the oil of C. camphora is recommended as herbal fungitoxicant against the fungal contamination of the raw materials. PMID:18322727

Singh, Priyanka; Srivastava, Bhawana; Kumar, Ashok; Dubey, N K

2008-10-01

9

Enhancement of somatic embryogenesis in camphor tree ( Cinnamomum camphora L.): osmotic stress and other factors affecting somatic embryo formation on hormone-free medium  

Microsoft Academic Search

The aim of this study was to improve the direct somatic embryogenesis and initiate embryogenic callus formation in camphor\\u000a tree (Cinnamomum camphora L.) on hormone-free medium. The influence of osmotic stress pretreatment of immature zygotic embryos (0.5 and 1.0 M solution\\u000a of sucrose for 12, 24, 48, 72, 96, 120, and 144 h at 4 or 25°C) before cultured on hormone-free medium,

Xueping Shi; Xigang Dai; Guofeng Liu; Manzhu Bao

2009-01-01

10

Enzymatic interesterification of palm stearin with Cinnamomum camphora seed oil to produce zero-trans medium-chain triacylglycerols-enriched plastic fat.  

PubMed

It is known that Cinnamomum camphora seed oil (CCSO) is rich in medium-chain fatty acids (MCFAs) or medium-chain triacylglycerols (MCTs). The purpose of the present study was to produce zero-trans MCTs-enriched plastic fat from a lipid mixture (500 g) of palm stearin (PS) and CCSO at 3 weight ratios (PS:CCSO 60:40, 70:30, 80:20, wt/wt) by using lipase (Lipozyme TL IM, 10% of total substrate) as a catalyst at 65 °C for 8 h. The major fatty acids of the products were palmitic acid (C16:0, 42.68% to 53.42%), oleic acid (C18:1, 22.41% to 23.46%), and MCFAs (8.67% to 18.73%). Alpha-tocopherol (0.48 to 2.51 mg/100 g), ?-tocopherol (1.70 to 3.88 mg/100 g), and ?-tocopherol (2.08 to 3.95 mg/100 g) were detected in the interesterified products. The physical properties including solid fat content (SFC), slip melting point (SMP), and crystal polymorphism of the products were evaluated for possible application in shortening or margarine. Results showed that the SFCs of interesterified products at 25 °C were 9% (60:40, PS:CCSO), 18.50% (70:30, PS:CCSO), and 29.2% (80:20, PS:CCSO), respectively. The ?' crystal form was found in most of the interesterified products. Furthermore, no trans fatty acids were detected in the products. Such zero-trans MCT-enriched fats may have a potential functionality for shortenings and margarines which may become a new type of nutritional plastic fat for daily diet. PMID:22515238

Tang, Liang; Hu, Jiang-ning; Zhu, Xue-mei; Luo, Li-ping; Lei, Lin; Deng, Ze-yuan; Lee, Ki-Teak

2012-04-01

11

Effects of Simulated Acid Rain on the Antioxidative System in Cinnamomum philippinense Seedlings  

Microsoft Academic Search

This study examined the importance of the antioxidative defense mechanism during the application of simulated acid rain (SAR)\\u000a pH 4, pH 3, pH 2, and pH 6 as control treatment in Cinnamomum philippinense seedlings. Analysis was carried out on 1, 10, and 15 days of spraying SAR. In our results, catalase (CAT), ascorbate peroxidase\\u000a (APx), guaiacol peroxidase (GPOD), and glutathione reductase

En-U Liu; Chiung-Pin Liu

2011-01-01

12

Enzymatic production of zero-trans plastic fat rich in ?-linolenic acid and medium-chain fatty acids from highly hydrogenated soybean oil, Cinnamomum camphora seed oil, and perilla oil by lipozyme TL IM.  

PubMed

In the present study, zero-trans ?-linolenic acid (ALA) and medium-chain fatty acids (MCFA)-enriched plastic fats were synthesized through enzymatic interesterification reactions from highly hydrogenated soybean oil (HSO), Cinnamomum camphora seed oil (CCSO), and perilla oil (PO). The reactions were performed by incubating the blending mixtures of HSO, CCSO, and PO at different weight ratios (60:40:100, 70:30:100, 80:20:100) using 10% (total weight of substrate) of Lipozyme TL IM at 65 °C for 8 h. After reaction, the physical properties (fatty acids profile, TAG composition, solid fat content, slip melting point, contents of tocopherol, polymorphic forms, and microstructures) of the interesterified products and their physical blends were determined, respectively. Results showed that the fatty acid compositions of the interesterified products and physical blends had no significant changes, while the content of MCFA in both interesterified products and physical blends increased to 8.58-18.72%. Several new types of TAG species were observed in interesterified products (SSL/SLS, PLO/LLS, and OLLn/LnLO/LOLn). It should be mentioned that no trans fatty acids (TFA) were detected in all products. As the temperature increased, the solid fat content (SFC) of interesterified products was obviously lower than that of physical blends. The SFCs of interesterified products (60:40:100, 70:30:100, and 80:20:100, HSO:CCSO:PO) at 25 °C were 6.5%, 14.6%, and 16.5%, respectively, whereas the counterparts of physical blends were 32.5%, 38.5%, and 43.5%, respectively. Meanwhile, interesterified products showed more ?' polymorphs than physical blends, in which ?' polymorph is a favorite form for production of margarine and shortening. Such zero-trans ALA and MCFA-enriched fats may have desirable physical and nutritional properties for shortenings and margarines. PMID:23350869

Zhao, Man-Li; Tang, Liang; Zhu, Xue-Mei; Hu, Jiang-Ning; Li, Hong-Yan; Luo, Li-Ping; Lei, Lin; Deng, Ze-Yuan

2013-02-13

13

Phenylalanine derived cyanogenic diglucosides from Eucalyptus camphora and their abundances in relation to ontogeny and tissue type.  

PubMed

The cyanogenic glucoside profile of Eucalyptus camphora was investigated in the course of plant ontogeny. In addition to amygdalin, three phenylalanine-derived cyanogenic diglucosides characterized by unique linkage positions between the two glucose moieties were identified in E. camphora tissues. This is the first time that multiple cyanogenic diglucosides have been shown to co-occur in any plant species. Two of these cyanogenic glucosides have not previously been reported and are named eucalyptosin B and eucalyptosin C. Quantitative and qualitative differences in total cyanogenic glucoside content were observed across different stages of whole plant and tissue ontogeny, as well as within different tissue types. Seedlings of E. camphora produce only the cyanogenic monoglucoside prunasin, and genetically based variation was observed in the age at which seedlings initiate prunasin biosynthesis. Once initiated, total cyanogenic glucoside concentration increased throughout plant ontogeny with cyanogenic diglucoside production initiated in saplings and reaching a maximum in flower buds of adult trees. The role of multiple cyanogenic glucosides in E. camphora is unknown, but may include enhanced plant defense and/or a primary role in nitrogen storage and transport. PMID:21945721

Neilson, Elizabeth H; Goodger, Jason Q D; Motawia, Mohammed Saddik; Bjarnholt, Nanna; Frisch, Tina; Olsen, Carl Erik; Mřller, Birger Lindberg; Woodrow, Ian E

2011-12-01

14

Spatial distribution and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in Camphor (Cinnamomum camphora) tree bark from Southern Jiangsu, China.  

PubMed

The concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) were investigated in Camphor tree bark from Southern Jiangsu, China. Tree bark samples were collected in August 2012. The ?15PAHs concentrations were ranged from 6.18 to 1560 ng g(-1)dry weight (dw), with an average value of 407 ng g(-1)dw. Generally, the concentrations of PAHs in the suburban areas were the highest, followed by urban and rural areas. Principal component analysis and diagnostic ratios results showed that vehicle emission, biomass and coal combustion and industrial emission were the major sources of PAHs in tree bark from Southern Jiangsu. Good correlation was found between tree bark and polyurethane foam (PUF) samplers, indicating that both of them respond well to the gas-phase PAHs monitoring. PMID:24480428

Zhou, Li; Dong, Liang; Huang, Yeru; Shi, Shuangxin; Zhang, Lifei; Zhang, Xiulan; Yang, Wenlong; Li, Lingling

2014-07-01

15

[Levels and possible sources of organochlorine pesticides (OCPs) in camphor (Cinnamomum camphora) tree bark from Southern Jiangsu, China].  

PubMed

Thirty-three camphor tree bark samples were collected from Southern Jiangsu in August 2012. They were analyzed for organochlorine pesticides (OCPs), including hexachlorobenzene (HCB), DDTs (o,p'-DDE, p,p'-DDE, o,p'-DDD, p,p'-DDD, o,p'-DDT and p,p'-DDT), trans-chlordane and cis-chlordane. The concentrations of HCB, sigma6 DDTs and sigma Chlordanes ranged (dw) from 0.31 ng x g(-1) to 1.81 ng x g(-1), 0.40 ng x g(-1) to 17.3 ng x g(-1) and n. d. to 1.03 ng x g(-1), respectively. Due to the high volatility, the spatial distribution of HCB in Southern Jiangsu was uniform. Compared to the other results, the HCB concentration in Southern Jiangsu was lower. The historical usage of technical DDT mixture and the dicofol-type DDT were the major sources of DDTs in southern Jiangsu. The TC/CC ratio is usually used to distinguish between aged and fresh chlordane. According to the ratio of TC/CC, the chlordane in the urban area was derived from the fresh application of technical chlordane, and that in the rural area was attributed to the historical usage. PMID:24881411

Zhou, Li; Zhang, Xiu-Lan; Yang, Wen-Long; Li, Ling-Ling; Shi, Shuang-Xin; Zhang, Li-Fei; Dong, Liang; Huang, Ye-Ru

2014-03-01

16

Pharmaceutical applications and phytochemical profile of Cinnamomum burmannii  

PubMed Central

Extensive studies have been carried out in the last decade to assess the pharmaceutical potential and screen the phytochemical constituents of Cinnamomum burmannii. Databases such as PubMed (MEDLINE), Science Direct (Embase, Biobase, biosis), Scopus, Scifinder, Google Scholar, Google Patent, Cochrane database, and web of science were searched using a defined search strategy. This plant is a member of the genus Cinnamomum and is traditionally used as a spice. Cinnamomum burmannii have been demonstrated to exhibit analgesic, antibacterial, anti-diabetic, anti-fungal, antioxidant, antirheumatic, anti-thrombotic, and anti-tumor activities. The chemical constituents are mostly cinnamyl alcohol, coumarin, cinnamic acid, cinnamaldehyde, anthocynin, and essential oils together with constituents of sugar, protein, crude fats, pectin, and others. This review presents an overview of the current status and knowledge on the traditional usage, the pharmaceutical, biological activities, and phytochemical constituents reported for C. burmannii.

Al-Dhubiab, Bandar E.

2012-01-01

17

Pharmaceutical applications and phytochemical profile of Cinnamomum burmannii.  

PubMed

Extensive studies have been carried out in the last decade to assess the pharmaceutical potential and screen the phytochemical constituents of Cinnamomum burmannii. Databases such as PubMed (MEDLINE), Science Direct (Embase, Biobase, biosis), Scopus, Scifinder, Google Scholar, Google Patent, Cochrane database, and web of science were searched using a defined search strategy. This plant is a member of the genus Cinnamomum and is traditionally used as a spice. Cinnamomum burmannii have been demonstrated to exhibit analgesic, antibacterial, anti-diabetic, anti-fungal, antioxidant, antirheumatic, anti-thrombotic, and anti-tumor activities. The chemical constituents are mostly cinnamyl alcohol, coumarin, cinnamic acid, cinnamaldehyde, anthocynin, and essential oils together with constituents of sugar, protein, crude fats, pectin, and others. This review presents an overview of the current status and knowledge on the traditional usage, the pharmaceutical, biological activities, and phytochemical constituents reported for C. burmannii. PMID:23055638

Al-Dhubiab, Bandar E

2012-07-01

18

Aporphine alkaloids of Cinnamomum mollissimum and their bioactivities.  

PubMed

A chemical investigation of the crude extracts of Cinnamomum mollissimum bark resulted in the isolation of five aporphine alkaloids, namely N-methyl-1,2,10-trimethoxyaporphine, N-methylhernagine, N-methylhemovine, hernagine and hernovine. Their structures were elucidated by spectral analysis. The alkaloid crude extract demonstrated significant antibacterial and antioxidant activities. PMID:24660455

Masnon, Fatin Fasihah; Hassan, Najmah P S; Ahmad, Farediah

2014-01-01

19

Nutritive Value, Levels of Polyphenols and AntiNutritional Factors in Sri Lankan Cinnamon (Cinnamomum Zeyalnicum) And Chinese Cinnamon (Cinnamomum Cassia)  

Microsoft Academic Search

The present study investigated the proximate composition, minerals, amino acids, polyphenolic compounds and presence of some anti- nutritional factors in Sri Lankan cinnamon (Cinnamomum Zeyanicum) and Chinese cinnamon (Cinnamomum cassia ) barks. The results showed that both bark samples contain high amounts of carbohydrates (47-55 g 100g -1), crude fiber (21-33 g 100g -1) and calcium (690-1157 mg 100g -1).

Khalid S. Al-Numair; Dilshad Ahmad; SaifEldein B. Ahmed; Abdullah H. Al-Assaf

20

The effect of butanolides from Cinnamomum tenuifolium on platelet aggregation.  

PubMed

This study investigated the effects of isotenuifolide and tenuifolide B from the stems of Cinnamomum tenuifolium on adenosine diphosphate (ADP)-induced human platelet aggregation. Treatment of human platelet-rich plasma with isotenuifolide (1 and 2 ?g/?L) and tenuifolide B (1, 2 and 4 ?g/?L) did not have any significant effect on human platelet aggregation in vitro, however, treatment of human platelet-rich plasma with isotenuifolide (4 ?g/?L) resulted in an inhibitory effect on platelet aggregation, suggesting the potential of this compound as an anti-atherosclerogenic agent in humans. Isotenuifolide is a new butanolide compound, whose structure was characterized by spectral analyses. PMID:24071989

Dong, Huei-Ping; Wu, Hui-Ming; Chen, Sheue-Jiun; Chen, Chung-Yi

2013-01-01

21

Determination of volatiles produced during radiation processing in Laurus cinnamomum  

NASA Astrophysics Data System (ADS)

In order to protect food from pathogenic microorganisms as well as increase its shelf-life, while keeping sensorial properties (e.g., odor and taste), which are important properties required by spice buyers, it is necessary to analyze volatile formation from irradiation of medicinal and food herbs. Possible changes in the odor of these herbs are evaluated by characterizing different radiation doses and effects on sensorial properties, in order to allow better application of the irradiation technology. The aim of the present study was to analyze volatile formation on cinnamon ( Laurus cinnamomum) samples after gamma irradiation. These samples were irradiated into plastic packages using a 60Co facility. Radiation doses applied were 0, 5, 10, 15, 20 and 25 kGy. For the analysis of the samples, solid-phase microextraction (SPME) was applied, while for the analysis of volatile compounds, CG/MS. Spice irradiation showed the highest decrease in volatile compounds. For L. cinnamomum, the irradiation decreased volatile compounds by nearly 56% and 89.5%, respectively, comparing to volatile from a sample which had not been previously irradiated.

Salum, D. C.; Araújo, M. M.; Fanaro, G. B.; Purgatto, E.; Villavicencio, A. L. C. H.

2009-07-01

22

Green synthesis of gold nanoparticles using Cinnamomum zeylanicum leaf broth  

NASA Astrophysics Data System (ADS)

Development of biologically inspired experimental processes for the synthesis of nanoparticles is an important branch of nanotechnology. The synthesis of gold nanoparticles using Cinnamomum zeylanicum leaf broth as the reducing agent is reported. The morphology of the particles formed consists of a mixture of gold nanoprisms and spheres with fcc (1 1 1) structure of gold. At lower concentrations of the extract, formation of prism shaped Au particles dominates, while at higher concentrations almost spherical particles alone are observed. Good crystallinity of the nanoparticles with fcc phase is evident from XRD patterns, clear lattice fringes in the high resolution TEM image and bright circular rings in the SAED pattern. Au nanoparticles grown are observed to be photoluminescent and the intensity of photoemission is found to increase with increase in leaf broth concentration. The ability to modulate the shape of nanoparticles as observed in this study for gold nanoparticles opens up the exciting possibility of developing further synthetic routes employing ecofriendly sources.

Smitha, S. L.; Philip, Daizy; Gopchandran, K. G.

2009-10-01

23

Medicinal properties of 'true' cinnamon (Cinnamomum zeylanicum): a systematic review  

PubMed Central

Background In traditional medicine Cinnamon is considered a remedy for respiratory, digestive and gynaecological ailments. In-vitro and in-vivo studies from different parts of the world have demonstrated numerous beneficial medicinal effects of Cinnamomum zeylanicum (CZ). This paper aims to systematically review the scientific literature and provide a comprehensive summary on the potential medicinal benefits of CZ. Methods A comprehensive systematic review was conducted in the following databases; PubMed, Web of Science, SciVerse Scopus for studies published before 31st December 2012. The following keywords were used: “Cinnamomum zeylanicum”, “Ceylon cinnamon”, “True cinnamon” and “Sri Lankan cinnamon”. To obtain additional data a manual search was performed using the reference lists of included articles. Results The literature search identified the following number of articles in the respective databases; PubMed=54, Web of Science=76 and SciVerse Scopus=591. Thirteen additional articles were identified by searching reference lists. After removing duplicates the total number of articles included in the present review is 70. The beneficial health effects of CZ identified were; a) anti-microbial and anti-parasitic activity, b) lowering of blood glucose, blood pressure and serum cholesterol, c) anti-oxidant and free-radical scavenging properties, d) inhibition of tau aggregation and filament formation (hallmarks of Alzheimer’s disease), e) inhibitory effects on osteoclastogenesis, f) anti-secretagogue and anti-gastric ulcer effects, g) anti-nociceptive and anti-inflammatory activity, h) wound healing properties and i) hepato-protective effects. The studies reported minimal toxic and adverse effects. Conclusions The available in-vitro and in-vivo evidence suggests that CZ has many beneficial health effects. However, since data on humans are sparse, randomized controlled trials in humans will be necessary to determine whether these effects have public health implications.

2013-01-01

24

Macro-microscopic examination of leaves of Cinnamomum malabatrum (Burm. f.) Blume sold as Tamalapatra  

PubMed Central

Leaves of Cinnamomum tamala Nees & Eberm. (Lauraceae) commonly known as ‘Tamalapatra’ is a highly reputed commodity in drug and spice trade. Its adulteration with other leaf species belonging to genus Cinnamomum is found to be a common practice in India and other parts of the world. Thorough macroscopic and microscopic investigations are essential to differentiate them. Survey of South Indian crude drug markets revealed that in place of C. tamala some other leaves of Cinnamomum species are sold. Fresh leaves of various Cinnamomum species, including C. tamala, growing in south India were collected and studied to establish their correct identity. Leaves sold in markets of S. India under the name of Tamalapatra were subjected for detailed macro-microscopic evaluation including maceration and powder microscopy. Leaves of Cinnamomum malabatrum showed many distinguishing macro-microscopic characters, which will serve as markers to differentiate them from C. tamala the official source of Tamalapatra. Though macroscopy will serve the purpose of identification of the entire drug, microscopy had revealed the identity of the commercial substitute even in fragmented and powdered form. Macro-microscopic identity of C. malabatrum is established in comparison with the official drug, further chemical and biological studies may be confirmative in deciding the leaves as a substitute or adulterant.

Sunil Kumar, K. N.

2013-01-01

25

Insecticidal and fumigant activities of Cinnamomum cassia bark-derived materials against Mechoris ursulus (Coleoptera: attelabidae).  

PubMed

The insecticidal and fumigant activities of Cinnamomum cassia (Blume) bark-derived materials against the oak nut weevil (Mechoris ursulus Roelofs) were examined using filter paper diffusion and fumigation methods and compared to those of the commercially available Cinnamomum bark-derived compounds (eugenol, salicylaldehyde, trans-cinnamic acid, and cinnamyl alcohol). The biologically active constituent of the Cinnamomum bark was characterized as trans-cinnamaldehyde by spectroscopic analysis. In a test with the filter paper diffusion method, trans-cinnamaldehyde showed 100 and 83.3% mortality at rates of 2.5 and 1.0 mg/filter paper, respectively. At 2.5 mg/paper, strong insecticidal activity was produced from eugenol (90.0% mortality) and salicylaldehyde (88. 9%), whereas trans-cinnamic acid revealed moderate activity (73.3%). At 5 mg/paper, weak insecticidal activity (50.0%) was produced from cinnamyl alcohol. In a fumigation test, the Cinnamomum bark-derived compounds were much more effective against M. ursulus larvae in closed cups than in open ones. These results indicate that the insecticidal activity of test compounds was attributable to fumigant action, although there is also significant contact toxicity. As a naturally occurring insect-control agent, the Cinnamomum bark-derived materials described could be useful as a new preventive agent against damage caused by M. ursulus. PMID:10888580

Park, I K; Lee, H S; Lee, S G; Park, J D; Ahn, Y J

2000-06-01

26

Safety assessment of standardised methanol extract of Cinnamomum burmannii.  

PubMed

The present study aims to evaluate the safety of methanol extract of Cinnamomum burmannii (MECB) by acute 14-day (single dose) and sub-chronic 28-day (repeated doses) oral administration to Sprague-Dawley rats. Our results showed that no toxicity was found in either acute or sub-chronic toxicity studies. MECB (containing 0.07% and 0.20% (w/w) of coumarin and trans-cinnamaldehyde, respectively), which was given orally at doses of 500, 1000 and 2000 mg/kg caused neither visible signs of toxicity nor mortality. No significant differences were observed in general condition, growth, organ weight, hematological parameters, biochemical values, or the gross and microscopic appearance of the organs from the treatment groups as compared to the control group. In conclusion, MECB did not cause any mortality nor did it cause any abnormalities in the necropsy and histopathology findings of treated rats. The LD50 for the MECB was found to be more than 2000 mg/kg. No adverse effects were observed in the treated rats at all the doses tested. The no-observed-adverse-effect level (NOAEL) for the 28-day study was determined to be 2000 mg/kg body weight/day. PMID:23827665

Ahmad, Mariam; Lim, Chung Pin; Akowuah, Gabriel Akyirem; Ismail, Nur Najihah; Hashim, Mohd Akmal; Hor, Sook Yee; Ang, Lee Fung; Yam, Mun Fei

2013-09-15

27

A potential low-coumarin cinnamon substitute: Cinnamomum osmophloeum leaves.  

PubMed

The essential oils from leaves of Taiwan's indigenous cinnamon (Cinnamomum osmophloeum ct. cinnamaldehyde) have similar constituents as compared to that from commercial bark cinnamons. This indigenous cinnamon has been proven to have excellent bioactivities. To understand whether this indigenous cinnamon contains a high level of the hepatotoxic compound, coumarin, as often seen in Cassia cinnamons, current research focused on determining the coumarin content in this indigenous cinnamon and screening the low-coumarin clones. The results demonstrated that the coumarin contents in all tested indigenous cinnamon clones were much lower than that found in Cassia cinnamons. In addition, this indigenous cinnamon contains about 80% (w/w) of cinnamaldehyde and 0.4-2.7% (w/w) of eugenol in its leaf essential oils. This combination could provide this indigenous cinnamon a better shelf life compared to that of regular commercial cinnamons. These results suggested that leaves of this indigenous cinnamon could be a potential resource for a safer cinnamon substitute. PMID:24475880

Yeh, Ting-Feng; Lin, Chun-Ya; Chang, Shang-Tzen

2014-02-19

28

Modeling seedling emergence  

Microsoft Academic Search

Most common approaches to predicting or documenting seedling emergence are imprecise. Mechanistic models that simulate seed dormancy and germination and seedling elongation as functions of measured or estimated environmental variables seem to be the most promising approach to the problem, but they also are the most difficult models to develop. These models will need to integrate soil water potential and

Frank Forcella; Roberto L. Benech Arnold; Rudolfo Sanchez; Claudio M. Ghersa

2000-01-01

29

An overview on chemical composition, bioactivity and processing of leaves of Cinnamomum tamala.  

PubMed

Dried leaves of Cinnamomum tamala, also known as Indian bay leaves, are a lesser-known spice used in the Indian subcontinent. It imparts a warm, peppery, clove-cinnamon like flavor to a variety of food preparations. Besides food applications, the leaves have also been traditionally used for curing a number of ailments and for other perceived health benefits. They find mention in the Aurvedic, Yunani, and other traditional medicinal literature. This review summarizes the effect of Cinnamomum tamala leaves on biological systems such as immune system, gastro-intestinal tract, liver and its antioxidant, antidiabetic, anti-inflammatory, anticancer, and antimicrobial activity. Chemical components that may be responsible for its flavor as well as bioactivity, have also been discussed. PMID:24236996

Sharma, Vasundhara; Rao, Lingamallu Jagan Mohan

2014-01-01

30

Temporal aspects of the fine-scale genetic structure in a population of Cinnamomum insularimontanum (Lauraceae)  

Microsoft Academic Search

Cinnamomum insularimontanum Hayata (Lauraceae) is an insect-pollinated, broad-leaved evergreen tree with bird-dispersed seeds. We used allozyme loci, Wright's fixation index, spatial autocorrelation statistics (Moran's I), and coancestry measures to examine changes in genetic structure among four age-classes within a recently founded study population (60×100 m area) in southern Korea. There were no significant differences in expected heterozygosity among age classes.

M Y Chung; J D Nason; B K Epperson; M G Chung

2003-01-01

31

5.NF Grass Seedlings  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: The students in Raulâs class were growing grass seedlings in different conditions for a science project. He noticed that Pabloâs seedlings were $1\\frac...

32

Antimicrobial activities of cinnamon oil and cinnamaldehyde from the Chinese medicinal herb Cinnamomum cassia Blume.  

PubMed

Both Cinnamomum verum J.S. Presl. and Cinnamomum cassia Blume are collectively called Cortex Cinnamonmi for their medicinal cinnamon bark. Cinnamomum verum is more popular elsewhere in the world, whereas C. cassia is a well known traditional Chinese medicine. An analysis of hydro-distilled Chinese cinnamon oil and pure cinnamaldehyde by gas chromatography/mass spectrometry revealed that cinnamaldehyde is the major component comprising 85% in the essential oil and the purity of cinnamaldehyde in use is high (> 98%). Both oil and pure cinnamaldehyde of C. cassia were equally effective in inhibiting the growth of various isolates of bacteria including Gram-positive (1 isolate, Staphylococcus aureus), and Gram-negative (7 isolates, E. coli, Enterobacter aerogenes, Proteus vulgaris, Pseudomonas aeruginosa, Vibrio cholerae, Vibrio parahaemolyticus and Samonella typhymurium), and fungi including yeasts (four species of Candida, C. albicans, C. tropicalis, C. glabrata, and C. krusei), filamentous molds (4 isolates, three Aspergillus spp. and one Fusarium sp.) and dermatophytes (three isolates, Microsporum gypseum, Trichophyton rubrum and T. mentagraphytes). Their minimum inhibition concentrations (MIC) as determined by agar dilution method varied only slightly. The MICs of both oil and cinnamaldehyde for bacteria ranged from 75 microg/ml to 600 microg/ml, for yeasts from 100 microg/ml to 450 microg/ml, for filamentous fungi from 75 microg/ml to 150 microg/ml, and for dermatophytes from 18.8 microg/ml to 37.5 microg/ml. The antimicrobial effectiveness of C. cassia oil and its major constituent is comparable and almost equivalent, which suggests that the broad-spectrum antibiotic activities of C. cassia oil are due to cinnamaldehyde. The relationship between structure and function of the main components of cinnamon oil is also discussed. PMID:16710900

Ooi, Linda S M; Li, Yaolan; Kam, Sheung-Lau; Wang, Hua; Wong, Elaine Y L; Ooi, Vincent E C

2006-01-01

33

Chemical variability in the essential oil of Cinnamomum tamala L. leaves from India.  

PubMed

The chemical composition of the essential oils obtained from the fresh leaves of Cinnamomum tamala Nees et Eberm. was determined by GC and GC-MS. The yield of the oil on a dry weight basis ranged from 1.2% to 3.9% (w/w). Phenyl propanoids constitute the major portion (88.9-95.0%) of the oils. Fifty-four compounds were identified from the oils. Eugenol (91.4-41.8%) was the main compound, followed by eugenyl acetate (0.0-47.1%) and ?-phellandrene (0.6-2.5%) in the analysed oils. PMID:22007840

Rana, Virendra S; Langoljam, Reena D; Verdeguer, Mercedes; Blázquez, Maria Amparo

2012-01-01

34

Inclusion reactions of ?-cyclodextrin and its derivatives with cinnamaldehyde in Cinnamomum loureirii essential oil  

Microsoft Academic Search

The inclusion reactions of ?-cyclodextrin (?-CD), heptakis (2,6-di-O-methyl)-?-CD (DM-?-CD), and mono[2-O-(2-hydroxy-propyl)]-?-CD (HP-?-CD) with cinnamaldehyde (CA) in Cinnamomum loureirii essential oil were investigated using spectrofluorimetry. The results revealed that the best inclusion time was 30 min and\\u000a the neutral pH conditions were more advantageous to the process. The stoichiometry of ?-CD including CA complex was 1:1 (molar\\u000a ratio). The inclusion constants decreased

Shan Jiang; Jia-Nuo Li; Zi-Tao Jiang

2010-01-01

35

Direct analysis in real time by mass spectrometric technique for determining the variation in metabolite profiles of Cinnamomum tamala Nees and Eberm genotypes.  

PubMed

Cinnamomum tamala Nees & Eberm. is an important traditional medicinal plant, mentioned in various ancient literatures such as Ayurveda. Several of its medicinal properties have recently been proved. To characterize diversity in terms of metabolite profiles of Cinnamomum tamala Nees and Eberm genotypes, a newly emerging mass spectral ionization technique direct time in real time (DART) is very helpful. The DART ion source has been used to analyze an extremely wide range of phytochemicals present in leaves of Cinnamomum tamala. Ten genotypes were assessed for the presence of different phytochemicals. Phytochemical analysis showed the presence of mainly terpenes and phenols. These constituents vary in the different genotypes of Cinnamomum tamala. Principal component analysis has also been employed to analyze the DART data of these Cinnamomum genotypes. The result shows that the genotype of Cinnamomum tamala could be differentiated using DART MS data. The active components present in Cinnamomum tamala may be contributing significantly to high amount of antioxidant property of leaves and, in turn, conditional effects for diabetic patients. PMID:22701361

Singh, Vineeta; Gupta, Atul Kumar; Singh, S P; Kumar, Anil

2012-01-01

36

Antibacterial properties and major bioactive components of cinnamon stick (Cinnamomum burmannii): activity against foodborne pathogenic bacteria.  

PubMed

Cinnamomum burmannii Blume (cinnamon stick) from Indonesia is a little-investigated spice. In this study, the antibacterial activity, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) of cinnamon stick extract were evaluated against five common foodborne pathogenic bacteria (Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, and Salmonella anatum). Cinnamon stick extract exhibited significant antibacterial properties. Major compounds in cinnamon stick were tentatively identified by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography (LC-MS) as a predominant volatile oil component ((E)-cinnamaldehyde) and several polyphenols (mainly proanthocyanidins and (epi)catechins). Both (E)-cinnamaldehyde and proanthocyanidins significantly contributed to the antibacterial properties. Additionally, scanning electron microscopy was used to observe morphological changes of bacteria treated with the crude extract of cinnamon stick and its major components. This study suggests that cinnamon stick and its bioactive components have potential for application as natural food preservatives. PMID:17567030

Shan, Bin; Cai, Yi-Zhong; Brooks, John D; Corke, Harold

2007-07-11

37

A new coumarin and cytotoxic activities of constituents from Cinnamomum cassia.  

PubMed

A new coumarin derivative, coumacasia (1) and eight known compounds, coumarin (2), cinnamaldehyde (3), 2-methoxycinnamaldehyde (4), 2-hydroxycinnamaldehyde (5), coniferaldehyde (6), cinnamic acid (7), 2-hydroxycinnamic acid (8), and cinnamic alcohol (9), were isolated from the methanol extract of Cinnamomum cassia. Their structures were elucidated by spectral data and by comparison with the reported literature. The cytotoxic activities of compounds 1-9 were evaluated with two human cancer cell lines, HL-60 and A-549. Compound 1 showed growth inhibitory effects in the HL-60 and A-549 cell lines with IC50 values of 8.2 +/- 0.5 and 11.3 +/- 1.1 microM, respectively. Compounds 3-6, and 8 exhibited moderate cytotoxicity with IC50 values ranging from 20.5 to 65.6 microM. PMID:24868863

Ngoc, Tran Minh; Nhiem, Nguyen Xuan; Khoi, Nguyen Minh; Son, Doan Cao; Hung, Tran Viet; Van Kiem, Phan

2014-04-01

38

Chemical Composition of the Essential Oils of Cinnamomum loureirii Nees. From China Obtained by Hydrodistillation and Microwave-assisted Hydrodistillation  

Microsoft Academic Search

The essential oils of the bark of young branches of Cinnamomum loureirii Nees. from China were isolated by hydrodistillation (HD) and microwave-assisted hydrodistillation (MHD) in yields of 5.8% and 6.1%, respectively. The chemical composition of the oils was examined by GC and GC\\/MS. Twenty components in the HD oil and 21 components in the MHD oil were identifed, representing 95.2%

Rong Li; Ying Wang; Zi-Tao Jiang; Shan Jiang

2010-01-01

39

Major chemotypes and antioxidative activity of the leaf essential oils of Cinnamomum osmophloeum Kaneh. from a clonal orchard  

Microsoft Academic Search

Essential oils of 92 cutting clones from a clonal orchard of Cinnamomum osmophloeum Kaneh. were obtained by hydrodistillation and characterised by gas chromatography–mass spectrometry. Our results showed that the yields of essential oils ranged between 0.09% and 2.65% (vol\\/fresh wt). The constituents of essential oils varied among samples. The major chemotypes classified in the individual cutting clones were cinnamaldehyde (50

Kuan-Hung Lin; Shu-Yin Yeh; Min-Yi Lin; Ming-Chih Shih; Kai-Ts’ung Yang; Shih-Ying Hwang

2007-01-01

40

Therapeutic effects on murine oral candidiasis by oral administration of cassia (Cinnamomum cassia) preparation.  

PubMed

We examined the effects of spices and herbs on Candida albicans growth using in vitro assay and therapeutic activity of some selected herbal preparations against murine oral candidiasis. All tested samples: lemongrass (Cymbopogon citratus), lemon balm (Melissa officinalis), thyme (Thymus vulgaris), rosemary (Rosmarinus officinalis), roselle (Hibiscus sabdariffa), green tea (Camellia sinensis), and cassia (Cinnamomum cassia) inhibited Candida mycelial growth in vitro. The results of this assay showed that the anti-Candida activity of lemongrass, green tea, and cassia is stronger than that of the other tested herbs. Oral administration of lemongrass or green tea did not result in significant improvement in the murine oral candidiasis, while the administration of cassia improved the symptoms and reduced the number of viable Candida cells in the oral cavity. The results of in vitro Candida growth assay including GC/MS analysis suggested that cinnamaldehyde in the cassia preparation was the principal component responsible for the inhibitory activity of Candida mycelial growth. These findings suggest that oral intake of a cassia preparation is a clinical candidate for a prophylactic or therapeutic tool against oral Candida infection. PMID:20185867

Taguchi, Yuuki; Takizawa, Toshio; Ishibashi, Hiroko; Sagawa, Takehito; Arai, Ryo; Inoue, Shigeharu; Yamaguchi, Hideyo; Abe, Shigeru

2010-01-01

41

Efficacy of an essential oil of Cinnamomum zeylanicum against Psoroptes cuniculi.  

PubMed

The aim of the present study was to investigate the in vitro and in vivo acaricidal effects of an essential oil of Cinnamomum zeylanicun leaves on Psoroptes cuniculi, a mange mite. In vitro, 2.5 ml of the essential oil diluted at different concentrations, from 10% to 0.03%, in paraffin oil were added to Petri dishes containing all motile stages of P. cuniculi. Mites mortality observed in these dishes was compared with that observed in untreated and treated (AcaCerulen R) control plates. In vivo, one group of six P. cuniculi infected rabbits was topically treated two times at seven days interval with two ml of the essential oil at the concentration of 2.5% in paraffin oil and compared with untreated and treated (AcaCerulen R) control groups of six rabbits each. After 24 h of contact, all concentrations of essential oil between 0.10 and 10% showed a good in vitro acaricidal efficacy if compared with the untreated controls (p<0.01), but only the concentrations between 0.16 and 10% turned out as active as the drug. In vivo, the treatment with the essential oil cured all infested rabbits and no statistical differences were observed with the treated control group. PMID:16487693

Fichi, G; Flamini, G; Zaralli, L J; Perrucci, S

2007-02-01

42

MAPLE Fabricated Fe3O4@Cinnamomum verum Antimicrobial Surfaces for Improved Gastrostomy Tubes.  

PubMed

Cinnamomum verum-functionalized Fe3O4 nanoparticles of 9.4 nm in size were laser transferred by matrix assisted pulsed laser evaporation (MAPLE) technique onto gastrostomy tubes (G-tubes) for antibacterial activity evaluation toward Gram positive and Gram negative microbial colonization. X-ray diffraction analysis of the nanoparticle powder showed a polycrystalline magnetite structure, whereas infrared mapping confirmed the integrity of C. verum (CV) functional groups after the laser transfer. The specific topography of the deposited films involved a uniform thin coating together with several aggregates of bio-functionalized magnetite particles covering the G-tubes. Cytotoxicity assays showed an increase of the G-tube surface biocompatibility after Fe3O4@CV treatment, allowing a normal development of endothelial cells up to five days of incubation. Microbiological assays on nanoparticle-modified G-tube surfaces have proved an improvement of anti-adherent properties, significantly reducing both Gram negative and Gram positive bacteria colonization. PMID:24979402

Anghel, Alina Georgiana; Grumezescu, Alexandru Mihai; Chirea, Mariana; Grumezescu, Valentina; Socol, Gabriel; Iordache, Florin; Oprea, Alexandra Elena; Anghel, Ion; Holban, Alina Maria

2014-01-01

43

Suppression effect of Cinnamomum cassia bark-derived component on nitric oxide synthase.  

PubMed

The inhibitory effects of Cinnamomum cassia bark-derived material on nitric oxide (NO) production in RAW 264.7 cells was determined through the evaluation of NO production and expression of inducible nitric oxide and compared to the effects of three commercially available compounds, cinnamyl alcohol, cinnamic acid, and eugenol. The biologically active constituents of C. cassia extract were characterized as trans-cinnamaldehyde by spectral analysis. The inhibitory effects varied with both chemical and concentration used. Potent inhibitory effects of cinnamaldehyde against NO production were 81.5 and 71.7% at 1.0 and 0.5 microg/microL, respectively, and a 41.2% inhibitory effect was revealed at 0.1 microg/microL. However, little or no activity was observed for cinnamic acid and eugenol. Suppression effects of cinnamaldehyde on inducible nitric oxide synthase expression were revealed by Western blot analysis. As a naturally occurring therapeutic agent, trans-cinnamaldehyde could be useful for developing new types of NO inhibitors. PMID:12475291

Lee, Hoi-Seon; Kim, Byung-Su; Kim, Moo-Key

2002-12-18

44

Polyketide and benzopyran compounds of an endophytic fungus isolated from Cinnamomum mollissimum: biological activity and structure  

PubMed Central

Objective To study bioactivity and compounds produced by an endophytic Phoma sp. fungus isolated from the medicinal plant Cinnamomum mollissimum. Methods Compounds produced by the fungus were extracted from fungal broth culture with ethyl acetate. This was followed by bioactivity profiling of the crude extract fractions obtained via high performance liquid chromatography. The fractions were tested for cytotoxicity to P388 murine leukemic cells and antimicrobial activity against bacteria and pathogenic fungi. Compounds purified from active fractions which showed antibacterial, antifungal and cytotoxic activities were identified using capillary nuclear magnetic resonance analysis, mass spectrometry and admission to AntiMarin database. Results Three known compounds, namely 4-hydroxymellein, 4,8-dihydroxy-6-methoxy-3-methyl-3,4-dihydro-1H-isochromen-1-one and 1-(2,6-dihydroxyphenyl) ethanone, were isolated from the fungus. The polyketide compound 4-hydroxymellein showed high inhibitory activity against P388 murine leukemic cells (94.6%) and the bacteria Bacillus subtilis (97.3%). Meanwhile, 4,8-dihydroxy-6-methoxy-3-methyl-3,4-dihydro-1H-isochromen-1-one, a benzopyran compound, demonstrated moderate inhibitory activity against P388 murine leukemic cells (48.8%) and the fungus Aspergillus niger (56.1%). The second polyketide compound, 1 (2,6-dihydroxyphenyl) ethanone was inactive against the tested targets. Conclusions These findings demonstrate the potential of endophytes as producers of pharmacologically important compounds, including polyketides which are major secondary metabolites in fungi.

Santiago, Carolina; Sun, Lin; Munro, Murray Herbert Gibson; Santhanam, Jacinta

2014-01-01

45

Profile of urinary and fecal proanthocyanidin metabolites from common cinnamon (Cinnamomum zeylanicum L.) in rats.  

PubMed

Cinnamon (Cinnamomum zeylanicum L.) bark is widely used as a spice and in traditional medicine. Its oligomeric and polymeric proanthocyanidins are believed to be partly responsible for the beneficial properties of the plant. We describe here the metabolic fate of cinnamon proanthocyanidins in the urine and feces of rats fed a suspension of the whole bark. The metabolites include ten mono-, di-, and tri- conjugated (epi)catechin phase II metabolites and more than 20 small phenolic acids from intestinal microbial fermentation. Some of these are sulfated conjugates. Feces contain intact (epi)catechin and dimers. This suggests that free radical scavenging species are in contact with the intestinal walls for hours after ingestion of cinnamon. The phenolic metabolite profile of cinnamon bark in urine is consistent with a mixture of proanthocyanidins that are depolymerized into their constitutive (epi)catechin units as well as cleaved into smaller phenolic acids during their transit along the intestinal tract, with subsequent absorption and conjugation into bioavailable metabolites. PMID:22383303

Mateos-Martín, María Luisa; Pérez-Jiménez, Jara; Fuguet, Elisabet; Torres, Josep Lluís

2012-04-01

46

Anti-Inflammatory Activities of Cinnamomum cassia Constituents In Vitro and In Vivo  

PubMed Central

We have investigated the anti-inflammatory effects of Cinnamomum cassia constituents (cinnamic aldehyde, cinnamic alcohol, cinnamic acid, and coumarin) using lipopolysaccharide (LPS)-stimulated mouse macrophage (RAW264.7) and carrageenan (Carr)-induced mouse paw edema model. When RAW264.7 macrophages were treated with cinnamic aldehyde together with LPS, a significant concentration-dependent inhibition of nitric oxide (NO), tumor necrosis factor (TNF-?), and prostaglandin E2 (PGE2) levels productions were detected. Western blotting revealed that cinnamic aldehyde blocked protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), nuclear transcription factor kappa B (NF-?B), and I?B?, significantly. In the anti-inflammatory test, cinnamic aldehyde decreased the paw edema after Carr administration, and increased the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the paw tissue. We also demonstrated cinnamic aldehyde attenuated the malondialdehyde (MDA) level and myeloperoxidase (MPO) activity in the edema paw after Carr injection. Cinnamic aldehyde decreased the NO, TNF-?, and PGE2 levels on the serum level after Carr injection. Western blotting revealed that cinnamic aldehyde decreased Carr-induced iNOS, COX-2, and NF-?B expressions in the edema paw. These findings demonstrated that cinnamic aldehyde has excellent anti-inflammatory activities and thus has great potential to be used as a source for natural health products.

Liao, Jung-Chun; Deng, Jeng-Shyan; Chiu, Chuan-Sung; Hou, Wen-Chi; Huang, Shyh-Shyun; Shie, Pei-Hsin; Huang, Guang-Jhong

2012-01-01

47

Space Station Live: Seedling Growth  

NASA Video Gallery

Public Affairs Officer Lori Meggs talks with Carol Jacobs, payload operations director at the Marshall Space Flight Center's POIC, about the Seedling Growth experiment talking place aboard the Inte...

48

Parts of a Corn Seedling  

NSDL National Science Digital Library

This illustrated guide to a corn seedling (Zea mays, Monocotyledon) is designed to help students recognize and learn the plant's individual parts. Along with an explanation of monocotyledon embryos, it includes a short description of the root system and coleoptile.

49

Impact of decomposing Cinnamomum septentrionale leaf litter on the growth of Eucalyptus grandis saplings.  

PubMed

A pot experiment was performed to study the impact of decomposing Cinnamomum septentrionale leaf litter on the growth of Eucalyptus grandis saplings. The experimental design scheme was 0 (CK), 40 (A1), 80 (A2) and 120 g pot(-1) (A3) of E. grandis leaves, and changes in the volatile oil chemical composition during litter decomposition were assessed in the present study. The results showed that C. septentrionale leaf litter inhibited the growth of E. grandis saplings, as determined by the height, basal diameter and chlorophyll content, after 69 d (T1). Five months after transplantation (T2), the height growth rate of the E. grandis saplings increased and then gradually reduced (A1: 40 g pot(-1) > A2: 80 g pot(-1) > A3: 120 g pot(-1) > CK: 0 g pot(-1)). After eleven months (T3), the variations in the height and basal diameter were the same as observed at T2, and the inhibition on leaf, branch, root and stem biomass increased with increasing leaf litter content. Gas chromatography-mass spectrometry (GC-MS) was used to identify the volatile compound composition. The results indicated that the C. septentrionale original leaf litter (S1) contained thirty-one volatile compounds, but the treated leaf litter S2 (which was mixed with soil for eleven months to simultaneously plant E. grandis saplings) only possessed fourteen volatile compounds, releasing many secondary metabolites in the soil during decomposition. Most of the volatile compounds were alcohols, monoterpenoids, sesquiterpenes, alkanes, alkene, esters and ketones. Most of the allelochemicals of C. septentrionale might be released during the initial decomposing process, inhibiting the growth of other plants, whereas some nutrients might be released later, promoting the height growth of plants. In conclusion, decomposing C. septentrionale leaf litter release of many allelochemicals in the soil that significantly inhibit the growth of E. grandis. PMID:23835358

Huang, Weiwei; Hu, Tingxing; Chen, Hong; Wang, Qian; Hu, Hongling; Tu, Lihua; Jing, Liao

2013-09-01

50

Activity of Cinnamomum osmophloeum leaf essential oil against Anopheles gambiae s.s  

PubMed Central

Background The increasing status of insecticide resistant mosquitoes in sub-Saharan Africa is a threatening alert to the existing control efforts. All sibling species of An. gambiae complex have evolved insecticide resistance in wild populations for different approved classes of the insecticides currently in use in the field. An alternative compound for vector control is absolutely urgently needed. In this study, the larvicidal activity and chemical composition of the Cinnamomum osmophloeum leaf essential oils were investigated. Methods C. osmophloeum leaf essential oils were extracted by hydrodistillation in a Clevenger-type apparatus for 6 hours, and their chemical compositions identified using GC-MS. These oils were evaluated against An. gambiae s.s. in both laboratory and semi-field situations. The WHO test procedures for monitoring larvicidal efficacy in malaria vectors were used. Results The composition of C. osmophloeum leaf essential oil has been found to have 11 active compounds. The most abundant compound was trans-cinnamaldehyde (70.20%) and the least abundant was caryophyllene oxide (0.08%). The larvicidal activity was found to be dosage and time dependant both in laboratory and semi-field environments with mortality ranging from 0% to 100%. The LC50 value was found to vary from 22.18 to 58.15 ?g/ml in the laboratory while in semi-field environments it was 11.91 to 63.63 ?g/ml. The LC90 value was found to range between 57.71 to 91.54 ?g/ml in the laboratory while in semi-field environments was 52.07 to 173.77 ?g/ml. Mortality ranged from 13% to 100% in the laboratory while in semi-field environments it ranged between 43% to 100% within mortality recording time intervals of 12, 24, 48, and 72 hours. Conclusions The larvicidal activity shown by C. osmophloeum leaf essential oil is a promising alternative to existing larvicides or to be incorporated in integrated larval source management compounds for An. gambiae s.s control. The efficacy observed in this study is attributed to both major and minor compounds of the essential oils.

2014-01-01

51

Methods for thermal stability enhancement of leaf essential oils and their main constituents from indigenous cinnamon (Cinnamomum osmophloeum).  

PubMed

The thermal stability of leaf essential oils from various Cinnamomum osmophloeum and their constituents was investigated for the first time. The results indicated that trans-cinnamaldehyde (Cin) content in eugenol-free essential oil from C. osmophloeum was affected by high temperatures. The retention of Cin (RC) decreased to 17.4% after the essential oil was incubated for 8 h at 100 °C. In contrast, essential oils containing eugenol showed greater thermal stability. Seven kinds of antioxidants were added to Cin to improve its thermal stability. Among them, eugenol endowed Cin with the best thermal stability. We also investigated the influence of various amounts of eugenol on the thermal stability of both essential oil and Cin. Both essential oil and Cin showed excellent thermal stability when 0.62 and 2.60% (v/v) eugenol were added. In short, the thermal stability of essential oil and Cin could be effectively improved by adding appropriate amounts of eugenol. PMID:23738884

Yeh, Hsin-Fu; Luo, Chi-Yuan; Lin, Chun-Ya; Cheng, Sen-Sung; Hsu, Yen-Ray; Chang, Shang-Tzen

2013-07-01

52

Ameliorative Effects of a Polyphenolic Fraction of Cinnamomum zeylanicum L. Bark in Animal Models of Inflammation and Arthritis  

PubMed Central

Cinnamon bark (Cinnamomum zeylanicum Syn C. verum, family: Lauraceae) is one of the oldest traditional medicines for inflammatory- and pain-related disorders. The objective of the present study was to evaluate the efficacy of the polyphenol fraction from Cinnamomum zeylanicum bark (CPP) in animal models of inflammation and rheumatoid arthritis. Dose-response studies of CPP (50, 100, and 200 mg/kg) used in a separate set of in vivo experiments were conducted in acute (carrageenan-induced rat paw edema), subacute (cotton pellet-induced granuloma), and sub-chronic (AIA, adjuvant-induced established polyarthrtis) models of inflammation in rats and the acetic acid-induced writhing model of pain in mice. Effects of CPP on cytokine (IL-2, IL-4, and IFN?) release from Concanavalin (ConA)-stimulated lymphocytes were also evaluated in vitro. CPP showed a strong and dose-dependent reduction in paw volume, weight loss reversal effects against carrageenan-induced paw edema, and cotton pellet-induced granuloma models in rats. CPP (200 mg/kg p.o. for 10 days) showed a significant reduction in elevated serum TNF-? concentration without causing gastric ulcerogenicity in the AIA model in rats. CPP also demonstrated mild analgesic effects during acute treatment as evidenced by the reduction in the writhing and paw withdrawal threshold of the inflamed rat paw during the acetic acid-induced writhing model and Randall-Selitto test. CPP was found to inhibit cytokine (IL-2, IL-4, and IFN?) release from ConA-stimulated lymphocytes in vitro. In conclusion, CPP demonstrated prominent action in animal models of inflammation and arthritis and therefore can be considered as a potential anti-rheumatic agent with disease-modifying action.

Rathi, Badal; Bodhankar, Subhash; Mohan, V.; Thakurdesai, Prasad

2013-01-01

53

Ameliorative Effects of a Polyphenolic Fraction of Cinnamomum zeylanicum L. Bark in Animal Models of Inflammation and Arthritis.  

PubMed

Cinnamon bark (Cinnamomum zeylanicum Syn C. verum, family: Lauraceae) is one of the oldest traditional medicines for inflammatory- and pain-related disorders. The objective of the present study was to evaluate the efficacy of the polyphenol fraction from Cinnamomum zeylanicum bark (CPP) in animal models of inflammation and rheumatoid arthritis. Dose-response studies of CPP (50, 100, and 200 mg/kg) used in a separate set of in vivo experiments were conducted in acute (carrageenan-induced rat paw edema), subacute (cotton pellet-induced granuloma), and sub-chronic (AIA, adjuvant-induced established polyarthrtis) models of inflammation in rats and the acetic acid-induced writhing model of pain in mice. Effects of CPP on cytokine (IL-2, IL-4, and IFN?) release from Concanavalin (ConA)-stimulated lymphocytes were also evaluated in vitro. CPP showed a strong and dose-dependent reduction in paw volume, weight loss reversal effects against carrageenan-induced paw edema, and cotton pellet-induced granuloma models in rats. CPP (200 mg/kg p.o. for 10 days) showed a significant reduction in elevated serum TNF-? concentration without causing gastric ulcerogenicity in the AIA model in rats. CPP also demonstrated mild analgesic effects during acute treatment as evidenced by the reduction in the writhing and paw withdrawal threshold of the inflamed rat paw during the acetic acid-induced writhing model and Randall-Selitto test. CPP was found to inhibit cytokine (IL-2, IL-4, and IFN?) release from ConA-stimulated lymphocytes in vitro. In conclusion, CPP demonstrated prominent action in animal models of inflammation and arthritis and therefore can be considered as a potential anti-rheumatic agent with disease-modifying action. PMID:23833722

Rathi, Badal; Bodhankar, Subhash; Mohan, V; Thakurdesai, Prasad

2013-06-01

54

Seed Mucilage Improves Seedling Emergence of a Sand Desert Shrub  

Microsoft Academic Search

The success of seedling establishment of desert plants is determined by seedling emergence response to an unpredictable precipitation regime. Sand burial is a crucial and frequent environmental stress that impacts seedling establishment on sand dunes. However, little is known about the ecological role of seed mucilage in seedling emergence in arid sandy environments. We hypothesized that seed mucilage enhances seedling

Xuejun Yang; Carol C. Baskin; Jerry M. Baskin; Guangzheng Liu; Zhenying Huang

2012-01-01

55

Relationships between physical and chemical attributes of congeneric seedlings: how important is seedling defence?  

Microsoft Academic Search

Summary 1. While herbivory is considered a major selective force operating in mature vegetation, much less is known about how herbivores affect the expression of defence at the seedling stage. In this study we quantified several chemical and physical properties, usually considered to affect seedling palatability, of 14 Western Australian Hakea species. We also determined whether seedling defences were related

M. E. Hanley; B. B. Lamont

2002-01-01

56

Planting frozen conifer seedlings: Warming trends and effects on seedling performance  

Microsoft Academic Search

In temperate climates, conifer seedlings are often held in frozen storage (-2 °C) for extended periods and then placed in cool storage (+2 °C) so the root plug can thaw prior to outplanting. Two plug temperature treatments were used to test the hypothesis that thawing seedlings prior to outplanting may be unnecessary: seedlings were planted with frozen root plugs (‘frozen

C. M. Kooistra; J. D. Bakker

2002-01-01

57

Isolinderanolide B, a Butanolide Extracted From the Stems of Cinnamomum subavenium, Inhibits Proliferation of T24 Human Bladder Cancer Cells by Blocking Cell Cycle Progression and Inducing Apoptosis  

Microsoft Academic Search

Isolinderanolide B (IOB), a butanolide extracted from the stems of Cinnamomum subavenium, was investigated for its antiproliferative activity in T24 human bladder cancer cells. To identity the anticancer mechanism of IOB, its effect on apoptosis, cell cycle distribution, and levels of p53, p21 Waf1\\/Cip1, Fas\\/APO-1 receptor, and Fas ligand was assayed. Enzyme-linked immunosorbent assay showed that the G0\\/G1 phase arrest

Kun-Hung Shen; En-Shyh Lin; Po-Lin Kuo; Chung-Yi Chen; Ya-Ling Hsu

2011-01-01

58

Effect of Cinnamon (Cinnamomum Cassia) intervention on Blood Glucose of Middle Aged Adult Male with Non Insulin Dependent Diabetes Mellitus (NIDDM)  

Microsoft Academic Search

The present study was conducted to find out the effect of oral administration of cinnamon (Cinnamomum cassia) on non insulin dependent diabetes mellitus (NIDDM) patients of Udaipur city (Rajasthan). Thirty type 2 diabetics were divided into two groups (15 in each) experimental and control group. Experimental group was supplemented with 2g cinnamon powder filled in capsules (4capsules\\/day\\/person) for 40 days.

Richa Soni; Vibha Bhatnagar

59

Polyamine metabolism during seedling development in rice  

Microsoft Academic Search

The main free amines identified during growth and development of rice seedlings were agmatine, putrescine, spermidine, diaminopropane and tyramine. Amine composition differed according to tissue and stages of development. Conjugated amines were only found in roots. We present evidence that arginine decarboxylase (ADC) regulates putrescine during the development of rice seedlings. When ADC action was blocked by DFMA (a-DL-difluoromethylarginine, a

L. Bonneaul; M. Carré; C. Dreumont; J. Martin-Tanguy

1994-01-01

60

Grass Seed Structure and Seedling Emergence  

NSDL National Science Digital Library

This activity discusses both seed structure and seedling emergence in monocots. Through active learning elements, photos and text students will discover the basic anatomy of seeds and the function of each structure. The process of seedling emergence is presented in detail including the difference between emergence in cool-season and warm-season grasses.

61

Phytotoxicity of thiocyanate to rice seedlings.  

PubMed

The acute toxicity of potassium thiocyanate (KSCN) and ammonium thiocyanate (NH(4)SCN) to rice seedlings was tested. Hydroponically-grown plants showed different responses to the two species of thiocyanate. NH(4)SCN caused more severe stress to rice seedlings than KSCN. A significant reduction in transpiration and relative growth was observed with all NH(4)SCN treatments (p < 0.01), while the effect of KSCN on rice seedlings was more evident at greater than 100 mg SCN/L (p < 0.01). Both chemicals had a negligible effect on total chlorophyll content in shoots of rice seedlings (p > 0.05). Although phyto-transport of thiocyanate was apparent, rice seedlings showed significantly higher removal potential for NH(4)SCN than KSCN. PMID:22310846

Yu, Xiao-Zhang; Zhang, Fu-Zhong; Li, Fan

2012-05-01

62

Acute and chronic antihypertensive effects of Cinnamomum zeylanicum stem bark methanol extract in L-NAME-induced hypertensive rats  

PubMed Central

Background Previous study showed that the aqueous extract of the stem bark of Cinnamomum zeylanicum possesses antihypertensive and vasodilatory properties. The present work investigates the acute and chronic antihypertensive effects of the methanol extract of Cinnamomum zeylanicum stem bark (MECZ) in L-NAME-induced hypertensive rats. Methods The acute antihypertensive effects of MECZ (5, 10 and 20 mg/kg) administered intravenously were evaluated in rats in which acute arterial hypertension has been induced by intravenous administration of L-NAME (20 mg/kg). For chronic antihypertensive effects, animals were treated with L-NAME (40 mg/kg/day) plus the vehicle or L-NAME (40 mg/kg/day) in combination with captopril (20 mg/kg/day) or MECZ (300 mg/kg/day) and compared with control group receiving only distilled water. All drugs were administered per os and at the end of the experiment that lasted for four consecutive weeks, blood pressure was measured by invasive method and blood samples were collected for the determination of the lipid profile. The heart and aorta were collected, weighed and used for both histological analysis and determination of NO tissue content. Results Acute intravenous administration of C. zeylanicum extract (5, 10 and 20 mg/kg) to L-NAME-induced hypertensive rats provoked a long-lasting decrease in blood pressure. Mean arterial blood pressure decreased by 12.5%, 26.6% and 30.6% at the doses of 5, 10 and 20 mg/kg, respectively. In chronic administration, MECZ and captopril significantly prevented the increase in blood pressure and organs’ weights, as well as tissue histological damages and were able to reverse the depletion in NO tissue’s concentration. The MECZ also significantly lower the plasma level of triglycerides (38.1%), total cholesterol (32.1%) and LDL-cholesterol (75.3%) while increasing that of HDL-cholesterol (58.4%) with a significant low atherogenic index (1.4 versus 5.3 for L-NAME group). Conclusion MECZ possesses antihypertensive and organ protective effects that may result from its ability to increase the production of the endogenous NO and/or to regulate dyslipidemia.

2013-01-01

63

Cinnamomum cassia essential oil inhibits ?-MSH-induced melanin production and oxidative stress in murine B16 melanoma cells.  

PubMed

Essential oils extracted from aromatic plants exhibit important biological activities and have become increasingly important for the development of aromatherapy for complementary and alternative medicine. The essential oil extracted from Cinnamomum cassia Presl (CC-EO) has various functional properties; however, little information is available regarding its anti-tyrosinase and anti-melanogenic activities. In this study, 16 compounds in the CC-EO have been identified; the major components of this oil are cis-2-methoxycinnamic acid (43.06%) and cinnamaldehyde (42.37%). CC-EO and cinnamaldehyde exhibited anti-tyrosinase activities; however, cis-2-methoxycinnamic acid did not demonstrate tyrosinase inhibitory activity. In murine B16 melanoma cells stimulated with ?-melanocyte-stimulating hormone (?-MSH), CC-EO and cinnamaldehyde not only reduced the melanin content and tyrosinase activity of the cells but also down-regulated tyrosinase expression without exhibiting cytotoxicity. Moreover, CC-EO and cinnamaldehyde decreased thiobarbituric acid-reactive substance (TBARS) levels and restored glutathione (GSH) and catalase activity in the ?-MSH-stimulated B16 cells. These results demonstrate that CC-EO and its major component, cinnamaldehyde, possess potent anti-tyrosinase and anti-melanogenic activities that are coupled with antioxidant properties. Therefore, CC-EO may be a good source of skin-whitening agents and may have potential as an antioxidant in the future development of complementary and alternative medicine-based aromatherapy. PMID:24051402

Chou, Su-Tze; Chang, Wen-Lun; Chang, Chen-Tien; Hsu, Shih-Lan; Lin, Yu-Che; Shih, Ying

2013-01-01

64

Identifying melanogenesis inhibitors from Cinnamomum subavenium with in vitro and in vivo screening systems by targeting the human tyrosinase.  

PubMed

Tyrosinase is known to be the first two and rate-limiting enzyme in the synthesis of melanin pigments responsible for colouring skin, hair and eyes. Tyrosinase inhibition is one major strategy used to treat hyperpigmentation. In human skin melanocytes, the cellular tyrosinase inhibition was examined by the conversion of l-tyrosine and oxidation of l-DOPA to dopaquinone. We evaluated the skin pigmentation inhibitor effects with both in vitro and in vivo systems to find skin-whitening agents without cytotoxic concerns. First, linderanolide B and subamolide A were isolated from the stems of Cinnamomum subavenium and exhibited mushroom tyrosinase inhibition. Then, these two herbal compounds were proved to have good pigmentation inhibitory abilities at low doses and demonstrated free cytotoxicities to normal human skin cells and zebrafish system. With molecular docking, in a virtual model of human tyrosinase, linderanolide B and subamolide A displayed meta(l) -coordinating interactions with Cu(2+) ions. The results obtained from biological assays showed that linderanolide B and subamolide A possessed anti-tyrosinase properties, which exhibited potential for application in medical cosmetology. PMID:21054558

Wang, Hui-Min; Chen, Chung-Yi; Wen, Zhi-Hong

2011-03-01

65

Cytotoxic and Antifungal Activities of 5-Hydroxyramulosin, a Compound Produced by an Endophytic Fungus Isolated from Cinnamomum mollisimum  

PubMed Central

An endophytic fungus isolated from the plant Cinnamomum mollissimum was investigated for the bioactivity of its metabolites. The fungus, similar to a Phoma sp., was cultured in potato dextrose broth for two weeks, followed by extraction with ethyl acetate. The crude extract obtained was fractionated by high-performance liquid chromatography. Both crude extract and fractions were assayed for cytotoxicity against P388 murine leukemic cells and inhibition of bacterial and fungal pathogens. The bioactive extract fraction was purified further and characterized by nuclear magnetic resonance, mass spectral and X-ray crystallography analysis. A polyketide compound, 5-hydroxyramulosin, was identified as the constituent of the bioactive fungal extract fraction. This compound inhibited the fungal pathogen Aspergillus niger (IC50 1.56??g/mL) and was cytotoxic against murine leukemia cells (IC50 2.10??g/mL). 5-Hydroxyramulosin was the major compound produced by the endophytic fungus. This research suggests that fungal endophytes are a good source of bioactive metabolites which have potential applications in medicine.

Santiago, Carolina; Fitchett, Chris; Munro, Murray H. G.; Jalil, Juriyati; Santhanam, Jacinta

2012-01-01

66

Antifungal and antioxidative potential of oil and extracts derived from leaves of Indian spice plant Cinnamomum tamala.  

PubMed

Plant—based antimicrobials and antioxidants represent a vast untapped source for medicines and food supplements and hence have enormous therapeutic potential. Present work reports the fungicidal potential of Cinnamomum tamala Nees & Eberm (Lauraceae) leaf oil against five food spoilage and pathogenic fungi. In addition antioxidant efficacy of seven different solvent extracts derived from leaf was also evaluated using in vitro models. The oil demonstrated potent antifungal activity against Aspergillus niger, A. fumigatus, Candida albicans, Rhizopus stolonifer and Penicillium spp. in agar diffusion assay. Zone of inhibition ranged from 17-25 mm. The MFC values of oil against all the test fungi were found to be 230?g/ml. Phytochemicals present in C. tamala leaf were extracted in several solvents for assessing their effect in oxidative defense. The extracts exhibited appreciable antioxidant activity in ?-carotene bleaching assay and reducing power assay. The antioxidative activities of extracts were compared with the activities of standard antioxidant compounds BHA and ascorbic acid. Petroleum ether, ethanol, acetone and chloroform extracts exhibited about 30-67% antioxidant activity in ?-carotene bleaching assay. Aqueous and ethanol extracts exhibited better reducing power which increased gradually with increasing amount of the extract concentration showing dose dependent response. Results indicated that natural phytochemicals present in C. tamala leaf extracts have potential to prevent growth of food spoilage/pathogenic fungi. In addition they also have capability to mitigate the oxidative stress by antioxidant response. PMID:23273204

Pandey, A K; Mishra, A K; Mishra, A

2012-01-01

67

Cinnamomum cassia Essential Oil Inhibits ?-MSH-Induced Melanin Production and Oxidative Stress in Murine B16 Melanoma Cells  

PubMed Central

Essential oils extracted from aromatic plants exhibit important biological activities and have become increasingly important for the development of aromatherapy for complementary and alternative medicine. The essential oil extracted from Cinnamomum cassia Presl (CC-EO) has various functional properties; however, little information is available regarding its anti-tyrosinase and anti-melanogenic activities. In this study, 16 compounds in the CC-EO have been identified; the major components of this oil are cis-2-methoxycinnamic acid (43.06%) and cinnamaldehyde (42.37%). CC-EO and cinnamaldehyde exhibited anti-tyrosinase activities; however, cis-2-methoxycinnamic acid did not demonstrate tyrosinase inhibitory activity. In murine B16 melanoma cells stimulated with ?-melanocyte-stimulating hormone (?-MSH), CC-EO and cinnamaldehyde not only reduced the melanin content and tyrosinase activity of the cells but also down-regulated tyrosinase expression without exhibiting cytotoxicity. Moreover, CC-EO and cinnamaldehyde decreased thiobarbituric acid-reactive substance (TBARS) levels and restored glutathione (GSH) and catalase activity in the ?-MSH-stimulated B16 cells. These results demonstrate that CC-EO and its major component, cinnamaldehyde, possess potent anti-tyrosinase and anti-melanogenic activities that are coupled with antioxidant properties. Therefore, CC-EO may be a good source of skin-whitening agents and may have potential as an antioxidant in the future development of complementary and alternative medicine-based aromatherapy.

Chou, Su-Tze; Chang, Wen-Lun; Chang, Chen-Tien; Hsu, Shih-Lan; Lin, Yu-Che; Shih, Ying

2013-01-01

68

Increasing antibiotic activity against a multidrug-resistant Acinetobacter spp by essential oils of Citrus limon and Cinnamomum zeylanicum.  

PubMed

The genus Acinetobacter has gained importance in recent years due to involvement in serious infections and antimicrobial resistance. Many plants have been evaluated not only for direct antimicrobial activity, but also as resistance modifying agents. The Essential oil of Citrus limon (EOCL) addition at 156.25?µgmL(-1) (MIC/8) sub-inhibitory concentration in the growth medium led to MIC decrease for amikacin, imipenem and meropenem. The Essential oil of Cinnamomum zeylanicum (EOCZ) addition at 78.125?µg?mL(-1) (MIC/8) sub-inhibitory concentrations in the growth medium caused drastic MIC reduction of amikacin. Results of combining antibiotics and essential oils had shown us a synergistic effect with both essential oils/amikacin combinations. An additive effect was observed with the combinations of both essential oils and gentamicin. The results of this study suggest that essential oil of C. limon and C. zeylanicum may suppress the growth of Acinetobacter species and could be a source of metabolites with antibacterial modifying activity. PMID:22191514

Guerra, Felipe Queiroga Sarmento; Mendes, Juliana Moura; Sousa, Janiere Pereira de; Morais-Braga, Maria F B; Santos, Bernadete Helena Cavalcante; Melo Coutinho, Henrique Douglas; Lima, Edeltrudes de Oliveira

2012-01-01

69

Seedling Diversity and the Homologies of Seedling Organs in the Order Poales (Monocotyledons)  

PubMed Central

Background and Aims Seedlings of monocots are much more diverse than those of other angiosperms, often with very derived character states. This makes morphological interpretation difficult. The morphology of seedlings of most of the 16 families of the Poales alliance are only incompletely known. The present study aims first to develop an unambiguous terminology for the description of monocotyledonous seedlings. This makes possible clear morphological comparisons and the use of homologous terms for organs. Finally, plotting of well defined characters onto a molecular tree allows the polarization of character states. Method Seedlings were grown in Petri dishes on moist filter paper under permanent light conditions and analysed using light and scanning electron microscopy. Only seeds collected at natural habitats or from plants with a well documented source were used. Seedling vouchers are deposited in the alcohol collection of Monocot seedlings in the Botanische Staatssammlung München (M). Key Results Based on an unambiguous terminology, seedlings of a great number of genera are described and presented as figures, representing all families of Poales except Ecdeiocoleaceae. Seedlings of Rapateaceae, Joinvilleaceae and Mayacaceae are described for the first time. Morphological comparisons reveal a plausible interpretation of even very modified organ structures, including those of the grass seedling. Conclusions This study demonstrates that detailed studies of seedling morphology can provide interesting morphological insights and also new facts for phylogenetic analyses. However, the morphological diversity of seedlings in the monocots is as yet incompletely known, and in some, e.g. Alismatales or Zingiberales, the seedling structure is particularly poorly understood in terms of comparative morphology.

Tillich, Hans-Jurgen

2007-01-01

70

Vehicular machine for transplanting vegetal seedlings  

US Patent & Trademark Office Database

A vehicular machine available for transplanting vegetal seedlings onto seedbed lines comprising; a planting unit which is furnished with a plurality of vegetal seedling mounting tables and planting levers for transplanting vegetal seedlings onto seedbed lines supplied from these mounting tables disposed on the back side of a working truck hauled by a tractive vehicle; and a working step which facilitates an operator to mount himself on the working truck in order to replenish vegetal seedlings to respective mounting tables of the planting unit. The working truck itself is held by a plurality of supporting wheels which are respectively aligned with the level line identical to that of those wheels of the tractive vehicle.

1995-04-04

71

DESIGN ISSUES FOR EVALUATING SEEDLING EXPOSURE STUDIES  

EPA Science Inventory

Tree seedling studies, covering a wide range of experimental conditions in pollutant treatment, species, facilities, and exposure regimes, have become commonplace in forestry research for assessing the actual and potential environmental effects of air pollutants on forest ecosyst...

72

Clinorotation affects soybean seedling morphology  

NASA Technical Reports Server (NTRS)

Although spaceflight does not appear to significantly affect seed germination, it can influence subsequent plant growth. On STS-3 and SL-2, decreased growth (measured as plant length, fresh weight, and dry weight) was noted for pine, oat, and mung bean. In the CHROMEX-01 and 02 experiments with Haplopappus and in the CHROMEX-03 experiment with Arabidopsis, enhanced root growth was noted in the space-grown plants. In the CHROMEX-04 experiments with wheat, both leaf fresh weight and leaf area were diminished in the space-grown plants but there was no difference in total plant height (CS Brown, HG Levine, and AD Krikorian, unpublished data). These data suggest that microgravity impacts growth by whole plant partitioning of the assimilates. The objective of the present study was to determine the influence of clinorotation on the growth and the morphology of soybean seedlings grown in the Biological Research In Canister (BRIC) flight hardware. This experiment provided baseline data for a spaceflight experiment (BRIC-3) flown on STS-63 (February 3-11, 1995).

Hilaire, Emmanuel; Guikema, James A.; Brown, Christopher S.

1995-01-01

73

Evaluation of the In vitro Anti-hyperglycemic Effect of Cinnamomum cassia Derived Phenolic Phytochemicals, via Carbohydrate Hydrolyzing Enzyme Inhibition.  

PubMed

Cinnamomum cassia (cinnamon) proanthocyanidins (PACs) are believed to have anti-hyperglycemic potential via stimulation of insulin sensitivity. The present study investigates the carbohydrate hydrolyzing enzyme inhibition of cinnamon PACs. Five grams of cinnamon bark powder were extracted in 100 mL acetone solution (CAE) (acetone: water: hydrochloric acid, 70:29.9:0.01) for 2 h at room temperature and in 100 mL deionized water for 30 min at 90 °C (CWE). PACs were purified from CAE using LH-20 (CAE-PAC) to be further evaluated. PAC contents were evaluated by 4-Dimethylaminocinnamaldehyde (DMAC) assay and yielded 795, 177 and 123 mg/g, for CAE-PAC, CAE and CWE respectively. The total phenolic contents of CAE and CWE were determined to be 152 and 134 mg/g respectively. All extracts were adjusted to the same PAC content (180, 90, 45 and 20 ?g) and the inhibitory activity against rat ?-glucosidase was determined. The CAE-PAC fraction had very low rat ?-glucosidase inhibitory activity, CAE had the highest (IC50 0.474 mg/mL total phenolic (TP) basis) followed by CWE (IC50 0.697 mg/mL TP basis). The specific maltase and sucrase inhibitory activities were determined and CAE (IC50 0.38 and 0.10 mg/mL TP basis) had higher inhibition than CWE (IC50 0.74 and 0.37 mg/mL TP basis). Results suggest that the observed bioactivity is not PAC dependent and that CAE has a higher anti-hyperglycemic potential than CWE via inhibition of carbohydrate hydrolyzing enzymes. PMID:24706251

Kang, B-H; Racicot, K; Pilkenton, S J; Apostolidis, E

2014-06-01

74

Effects of Cinnamomum zeylanicum (Ceylon cinnamon) on blood glucose and lipids in a diabetic and healthy rat model  

PubMed Central

Objectives: To evaluate short- and long-term effects of Cinnamomum zeylanicum on food consumption, body weight, glycemic control, and lipids in healthy and diabetes-induced rats. Materials and Methods: The study was conducted in two phases (Phase I and Phase II), using Sprague-Dawley rats in four groups. Phase I evaluated acute effects on fasting blood glucose (FBG) (Groups 1 and 2) and on post-oral glucose (Groups 3 and 4) blood glucose. Groups 1 and 3 received distilled-water and Groups 2 and 4 received cinnamon-extracts. Phase II evaluated effects on food consumption, body weight, blood glucose, and lipids over 1 month. Group A (n = 8, distilled-water) and Group B (n = 8, cinnamon-extracts) were healthy rats, while Group C (n = 5, distilled-water) and Group D (n = 5, cinnamon-extracts) were diabetes-induced rats. Serum lipid profile and HbA1c were measured on D-0 and D-30. FBG, 2-h post-prandial blood glucose, body weight, and food consumption were measured on every fifth day. Results: Phase I: There was no significant difference in serial blood glucose values in cinnamon-treated group from time 0 (P > 0.05). Following oral glucose, the cinnamon group demonstrated a faster decline in blood glucose compared to controls (P < 0.05). Phase II: Between D0 and D30, the difference in food consumption was shown only in diabetes-induced rats (P < 0.001). Similarly, the significant difference following cinnamon-extracts in FBG and 2-h post-prandial blood glucose from D0 to D30 was shown only in diabetes-induced rats. In cinnamon-extracts administered groups, total and LDL cholesterol levels were lower on D30 in both healthy and diabetes-induced animals (P < 0.001). Conclusions: C. zeylanicum lowered blood glucose, reduced food intake, and improved lipid parameters in diabetes-induced rats.

Ranasinghe, Priyanga; Perera, Sanja; Gunatilake, Mangala; Abeywardene, Eranga; Gunapala, Nuwan; Premakumara, Sirimal; Perera, Kamal; Lokuhetty, Dilani; Katulanda, Prasad

2012-01-01

75

Stimulatory effects of extract prepared from the bark of Cinnamomum cassia blume on the function of osteoblastic MC3T3-E1 cells.  

PubMed

The ethanol extract from the bark of Cinnamomum cassia Blume (CCE) was tested for estrogenic activity. CCE (4-60 microg/mL) significantly induced the growth of MCF-7 cells, an ER-positive human breast cancer cell line, over that of untreated control cells (p < 0.05). In the ER competitive binding assay, CCE showed higher affinity with ERbeta compared with ERalpha. To investigate the bioactivities of CCE, which act on bone metabolism, the effects of CCE on the function of osteoblastic MC3T3-E1 cells and the production of local factors in osteoblasts were studied. CCE (4-60 microg/mL) dose-dependently increased the survival of MC3T3-E1 cells. In addition, CCE (10 and 50 microg/mL) increased alkaline phosphatase (ALP) activity, collagen synthesis and osteocalcin secretion in MC3T3-E1 cells. Treatment with CCE (10 and 50 microg/mL) prevented apoptosis induced by TNF-alpha (10(-10) m) in osteoblastic cells. In the presence of TNF-alpha, culture with CCE (10-100 microg/mL) for 48 h inhibited the production of IL-6 and nitric oxide in osteoblastic MC3T3-E1 cells. These results suggest that Cinnamomum cassia has a direct stimulatory effect on bone formation in vitro and may contribute to the prevention of osteoporosis and inflammatory bone diseases. PMID:16906639

Lee, Kyung-Hee; Choi, Eun-Mi

2006-11-01

76

Seedling growth and development on space shuttle  

NASA Technical Reports Server (NTRS)

Young pine seedlings, and mung bean and oat seeds were flown on shuttle flights, STS-3 and STS-51F, in March, 1982 and July/August, 1985, respectively. The plant growth units built to support the two experiments functioned mechanically as anticipated and provided the necessary support data. Pine seedlings exposed to the microgravity environment of the space shuttle for 8 days continued to grow at a rate similar to ground controls. Pine stems in flight seedlings, however, averaged 10 to 12% less lignin than controls. Flight mung beans grew slower than control beans and their stems contained about 25% less lignin than control seedlings. Reduced mung bean growth in microgravity was partly due to slower germination rate. Lignin also was reduced in flight oats as compared to controls. Oats and mung beans exhibited upward growing roots which were not observed in control seedlings. Chlorophyll A/B ratios were lower in flight tissues than controls. The sealed PGCs exhibited large variations in atmospheric gas composition but the changes were similar between flight and ground controls. Ethylene was present in low concentrations in all chambers.

Cowles, J.; Lemay, R.; Jahns, G.

1994-01-01

77

Seedling growth and development on space shuttle  

NASA Astrophysics Data System (ADS)

Young pine seedlings, and mung bean and oat seeds were flown on shuttle flights, STS-3 and STS-51F, in March, 1982 and July/August, 1985, respectively. The plant growth units built to support the two experiments functioned mechanically as anticipated and provided the necessary support data. Pine seedlings exposed to the microgravity environment of the space shuttle for 8 days continued to grow at a rate similar to ground controls. Pine stems in flight seedlings, however, averaged 10 to 12% less lignin than controls. Flight mung beans grew slower than control beans and their stems contained about 25% less lignin than control seedlings. Reduced mung bean growth in microgravity was partly due to slower germination rate. Lignin also was reduced in flight oats as compared to controls. Oats and mung beans exhibited upward growing roots which were not observed in control seedlings. Chlorophll A/B ratios were lower in flight tissues than controls. The sealed PGCs exhibited large variations in atmospheric gas composition but the changes were similar between flight and ground controls. Ethylene was present in low concentrations in all chambers.

Cowles, J.; Lemay, R.; Jahns, G.

1994-11-01

78

[Seedling index of Salvia miltiorrhiza and its simulation model].  

PubMed

Through the correlation analysis on the quantitative traits and their ratios of Salvia miltiorrhiza seedlings and seedling quality, a series of representative indices reflecting the seedling quality of the plant species were determined, and the seedling index suitable to the S. miltiorrhiza seedlings was ascertained by correlation degree analysis. Meanwhile, based on the relationships between the seedling index and the air temperature, solar radiation and air humidity, a simulation model for the seedling index of S. miltiorrhiza was established. The experimental data of different test plots and planting dates were used to validate the model. The results showed that the root diameter, stem diameter, crown dry mass, root dry mass, and plant dry mass had significant positive relationships with the other traits, and could be used as the indicators of the seedling's health. The seedling index of S. miltiorrhiza could be calculated by (stem diameter/root diameter + root dry mass/crown dry mass) x plant dry mass. The stem diameter, root dry mass, crown dry mass and plant dry mass had higher correlations with the seedling index, and thus, the seedling index determined by these indicators could better reflect the seedling's quality. The coefficient of determination (R2) between the predicted and measured values based on 1:1 line was 0.95, and the root mean squared error (RMSE) was 0.15, indicating that the model established in this study could precisely reflect the quantitative relationships between the seedling index of S. miltiorrhiza and the environmental factors. PMID:23359940

Huang, Shu-Hua; Xu, Fu-Li; Wang, Wei-Ling; Du, Jun-Bo; Ru, Mei; Wang, Jing; Cao, Xian-Yan

2012-10-01

79

Spring Burn Aids Longleaf Pine Seedling Height Growth.  

National Technical Information Service (NTIS)

Prescribed burning in midspring may stimulate height growth of longleaf pine seedling. Seedlings were planted on sandy and clayey sites that were prescribed burned 2 years later. Treatments were cool, moderate, and hot burns and an unburned control. The h...

W. R. Maple

1977-01-01

80

Density and Age Affect Performance of Containerized Loblolly Pine Seedlings.  

National Technical Information Service (NTIS)

Loblolly pine seedlings were grown in 1 x 5 inch biodegradable Plastic tubes for 10, 12, and 14 weeks at densities of 42, 84, 126 and 168 per square foot. The report evaluates the performance of the containerized seedlings.

J. P. Barnett

1980-01-01

81

Guide to the Care and Planting of Southern Pine Seedlings.  

National Technical Information Service (NTIS)

This booklet is designed to encourage landowners, land managers, county foresters, forestry consultants, and nursery managers to be certain that their seedlings receive proper care. As a reminder, it reviews the elements of seedling care in an idealized r...

1996-01-01

82

USE OF SEWAGE SLUDGE FOR FOREST-TREE SEEDLING PRODUCTION  

EPA Science Inventory

Research was undertaken to determine the beneficial and harmful effects of using dewatered, digested sewage sludge in: (1) containerized production of forest tree seedlings, (2) tree seedling production in a conventional outdoor nursery, (3) establishment and growth of transplant...

83

Changes of nucleic acids of wheat seedlings under spaceflight conditions  

NASA Technical Reports Server (NTRS)

The effects of space flight on the growth of wheat seedlings and their nucleic acid content were studied. It was shown that both space and ground seedlings have almost the same appearance, dry weight and nucleic acid content in the root, coleoptile and leaves. The only difference found is in the RNA and DNA content, which is twice as much in the ground seedling apices as in the space-grown seedlings.

Sytnyk, K. M.; Musatenko, L. I.

1983-01-01

84

Fusarium wilt of Prunus armeniaca seedlings.  

PubMed

Fusarium solani (Mart.) Sacc. was found to be the causal pathogen of Fusarium wilt of Prunus armeniaca seedlings. The fungus pathogenicity could be correlated with the increase in its mycelial growth and conidial germination under the influence of the host root exudates, volatile and gaseous exudates of either germinating seeds or roots, and the content of the host seedlings. Chromatographic and biological detection for indol derivatives in host root exudates indicated the presence of beta-indolacetic acid and indol-3-carbonic acid. Benzaldehyde, acetaldehyde, ethanol, ethylene, in addition to carbon dioxide, were among the volatile and gaseous exudates of either germinating seeds or roots of the host. PMID:878711

Afifi, A F

1977-01-01

85

An outbreak of yellow mold of peanut seedlings in Texas  

Microsoft Academic Search

Yellow mold of peanut (Arachis hypogaea) seedlings caused by Aspergillus flavus was first observed during May 1984 in a commercial peanut farm in south Texas. The mold caused preemergence rotting of peanut seed and seedlings. On emerged seedlings the infection was largely restricted to cotyledons. The diseased plants were chlorotic, stunted, and leaflets were reduced in size with pointed tips

P. Subrahmanyam; D. H. Smith; R. A. Raber; E. Shepherd

1987-01-01

86

Persistence of deltamethrin against Hylobius abietis on Norway spruce seedlings  

Microsoft Academic Search

The pine weevil Hylobius abietis L. is major threat to forest regeneration in the Nordic countries. The persistence of the deltamethrin insecticide used against pine weevil on Norway spruce seedlings was studied after the seedlings were dipped or sprayed. Insecticide application was timed to occur either before or after frozen storage. Bioassays with the stems of Norway spruce seedlings were

Heli Viiri; Anneli Tuomainen; Leo Tervo

2007-01-01

87

Seed Mucilage Improves Seedling Emergence of a Sand Desert Shrub  

PubMed Central

The success of seedling establishment of desert plants is determined by seedling emergence response to an unpredictable precipitation regime. Sand burial is a crucial and frequent environmental stress that impacts seedling establishment on sand dunes. However, little is known about the ecological role of seed mucilage in seedling emergence in arid sandy environments. We hypothesized that seed mucilage enhances seedling emergence in a low precipitation regime and under conditions of sand burial. In a greenhouse experiment, two types of Artemisia sphaerocephala achenes (intact and demucilaged) were exposed to different combinations of burial depth (0, 5, 10, 20, 40 and 60 mm) and irrigation regimes (low, medium and high, which simulated the precipitation amount and frequency in May, June and July in the natural habitat, respectively). Seedling emergence increased with increasing irrigation. It was highest at 5 mm sand burial depth and ceased at burial depths greater than 20 mm in all irrigation regimes. Mucilage significantly enhanced seedling emergence at 0, 5 and 10 mm burial depths in low irrigation, at 0 and 5 mm burial depths in medium irrigation and at 0 and 10 mm burial depths in high irrigation. Seed mucilage also reduced seedling mortality at the shallow sand burial depths. Moreover, mucilage significantly affected seedling emergence time and quiescence and dormancy percentages. Our findings suggest that seed mucilage plays an ecologically important role in successful seedling establishment of A. sphaerocephala by improving seedling emergence and reducing seedling mortality in stressful habitats of the sandy desert environment.

Yang, Xuejun; Baskin, Carol C.; Baskin, Jerry M.; Liu, Guangzheng; Huang, Zhenying

2012-01-01

88

Analysis for an environmental friendly seedling breeding system  

NASA Astrophysics Data System (ADS)

Most seedlings of crops are produced in solar greenhouse or nursery, from which some problems about energy waste and environment pollution arise. This study aims at investigating the characteristics and effect of an environmental friendly type seedling breeding system. The results demonstrate that crops can grow with a short period and little pollution in the new seedling breeding system with total manpower controllable environment that is not influenced by geography, climate and other natural conditions. By multilayer, nonplanar seedling breeding and annual batches arrangement, utilization ratio of unit area land and seedlings yield can be improved for several times and even more than 10 times. Conclusions can be obtained from the tomato seedling breeding experiments: (1) each growth index of tomato seedlings that are under the conditions of 291 ?mol/m 2 s artificial illumination intensity is remarkably better than those produced in greenhouse with natural lights. (2) The environment of the seedling breeding system can be accurately controlled. The segmented temperature changed management can be applied according to the photosynthetic characteristics of plants, and not affected by the outside environment, which makes each growth index of tomato seedling constant in different seasons. The seedlings thus grow strong and can achieve the level of commodity seedlings after 20-30 days. (3) The temperature and humidity environment of the seedling breeding system can be accurately controlled according to plants growth demands.

Qu, Y. H.; Wei, X. M.; Hou, Y. F.; Chen, B.; Chen, G. Q.; Lin, C.

2009-04-01

89

ACID FOG EFFECTS ON CONIFER SEEDLINGS  

EPA Science Inventory

Experiments were performed to assess the effects of acid fog on foliar injury, biomass production, and nutrient leaching in selected conifers. ne-year old seedlings of Pseudotsuga menzieii, Pinus ponderosa, Tsuga heterophylla and Thuja plicata were exposed episodically to fog eve...

90

GREENING BARLEY SEEDLINGS UNDER HIGH TEMPERATURE  

Microsoft Academic Search

Summary. The influence of heating on the structure and functional activity of photosynthetic membranes in greening barley seedlings was studied. It was observed that plants respond differently under different heat treatments (40, 45 and 500Ń). It was also observed that elevated temperature (400Ń) enhances the stability of thylakoid membrane, reducing overall membrane fluidity. Interaction and mutual regulation of xanthophyll cycle

Y. A. Maiseyenkava; N. L. Pshybytko; L. F. Kabashnikova

2005-01-01

91

Conifer seedling nursery worker exposure to glyphosate  

Microsoft Academic Search

This study addresses the measurements of glyphosate exposure received by 14 workers employed at two tree nurseries. The applicators, weeders, and scouts monitored all wore normal work clothing, which for applicators was a protective suit, rubber gloves and boots. Measurements were made of the glyphosate that was dislodged from conifer seedlings during water rinses taken twice weekly from May through

T. L. Lavy; J. E. Cowell; J. R. Steinmetz; J. H. Massey

1992-01-01

92

Lectins in Castor Bean Seedlings 1  

PubMed Central

The amounts of the two lectins (ricin and Ricinus communis agglutinin) in tissues of castor bean seedlings were followed during germination and early growth. For measurement, lectins in extracts were separately eluted from Sepharose columns; an antibody to the agglutinin was also used to detect the lectins by immunodiffusion. The endosperm of the dry seed contains 3.5 mg total lectin (5.6% of the total seed protein), which declines by 50% by day 4 and more rapidly thereafter as the tissue is completely consumed. The cotyledons of the dry seed also contain lectins but the amounts are less than 1% of those in the endosperm, and, as in the endosperm, they are constituents of the albumin fraction of the isolated protein bodies. No lectins were detected in the green cotyledons of 10-day seedlings that had been exposed to light from day 5. The embryonic axes of 2-day seedlings contained very small amounts of lectins but they were not detectable in the aerial parts of seedlings grown for 3 weeks or in cells from endosperm grown in tissue culture. The ability of proteinases and glycosidases (isolated from endosperm of 4-day seedlings) to hydrolyze the lectins was examined. No hydrolysis of the two lectins was observed, but the subunits, separated by reduction with 2-mercaptoethanol, were hydrolyzed slowly by a proteinase and some release of mannose was observed in the presence of the glycosidases. Ricin was converted to its subunits by cysteine and an enzyme in an endosperm extract accelerated chain separation by glutathione. Images Fig. 3

Harley, Suzanne M.; Beevers, Harry

1986-01-01

93

Antigenotoxic effects of three essential oils in diploid yeast ( Saccharomyces cerevisiae) after treatments with UVC radiation, 8MOP plus UVA and MMS  

Microsoft Academic Search

Essential oils (EOs) extracted from medicinal plants such as Origanum compactum, Artemisia herba alba and Cinnamomum camphora are known for their beneficial effects in humans. The present study was undertaken to investigate their possible antigenotoxic effects in an eukaryotic cell system, the yeast Saccharomyces cerevisiae. The EOs alone showed some cytotoxicity and cytoplasmic petite mutations, i.e. mitochondrial damage, but they

F. Bakkali; S. Averbeck; D. Averbeck; A. Zhiri; D. Baudoux; M. Idaomar

2006-01-01

94

Cytotoxicity and gene induction by some essential oils in the yeast Saccharomyces cerevisiae  

Microsoft Academic Search

In order to get an insight into the possible genotoxicity of essential oils (EOs) used in traditional pharmacological applications we tested five different oils extracted from the medicinal plants Origanum compactum, Coriandrum sativum, Artemisia herba alba, Cinnamomum camphora (Ravintsara aromatica) and Helichrysum italicum (Calendula officinalis) for genotoxic effects using the yeast Saccharomyces cerevisiae. Clear cytotoxic effects were observed in the

F. Bakkali; S. Averbeck; D. Averbeck; A. Zhiri; M. Idaomar

2005-01-01

95

On the biomechanics of seedling anchorage  

NASA Astrophysics Data System (ADS)

We propose a minimal model for the response of vegetation to pullout constraints at early development stage. We try to capture both the average mechanical properties of the root system and the stochastic component of the uprooting process of seedlings. We identify a minimal set of relevant physical components in the purpose of quantifying the uprooting process: length of the root fibres, elastic response of the fibres and adhesion between the roots and the soil matrix. We present for validation a dataset extracted from Edmaier et al. (under revision), accounting for 98 uprooting experiments using Avena sativa L. seedlings (common oat), growing in non-cohesive sediment under controlled conditions. The corresponding root system has a very simple architecture, with three root fibres of different lengths. The response of the system to the constraint is however complex: the stress-strain signal presents sudden jumps followed by partial elastic recoveries. The analysis of the jumps and partial recoveries gives an insight into the resilience of the system. The anchorage of less mature seedlings rapidly collapses after the peak force has been reached, while more mature seedlings usually recover from partial failures. We explore this crossover with our validation dataset. The type of seedlings we study has been used in flume experiments investigating the feedbacks between the vegetation and the river morphodynamics (see for example Perona et al. (2012)). An understanding of the characteristics of the uprooting curve (maximal uprooting force and total uprooting work) of such vegetation reveals the ability of seedlings to withstand environmental constraints in terms of duration or intensity (see Edmaier et al., under revision), and is therefore helpful for planning future experiments. REFERENCES - P. Perona, P. Molnar, B. Crouzy, E. Perucca, Z. Jiang, S. McLelland, D. Wüthrich, K. Edmaier, R. Francis, C. Camporeale, et al., Biomass selection by floods and related timescales: Part 1. Experimental observations, Advances in Water Resources 39 (2012) 85-96. - K. Edmaier, P. Burlando and P. Perona, Mechanisms of vegetation uprooting by flow in alluvial non-cohesive sediment. Hydrology And Earth System Sciences, vol. 15, p. 1615-1627, 2011. - K. Edmaier, B. Crouzy, P. Perona, Experimental characterization of root anchoring in non-cohesive sediment, Earth Surface Processes and Landforms (under revision).

Crouzy, Benoît; Edmaier, Katharina; Perona, Paolo

2014-05-01

96

Early events in geotropism of seedling shoots  

NASA Technical Reports Server (NTRS)

Developments during the first ten minutes of geotropic stimulation in plant seedling shoots are reviewed. Topics include induction and curvature; early processes; the relationship between auxin, electric field, calcium, and differential growth; gravity reception leading to Went-Cholodny transport; and comparison of root and shoot. Early processes reviewed are sedimentation of amyloplasts, release of ethylene, rise of electrical and auxin asymmetry, redistribution of calcium, asymmetric vascular transport, increase in tendency to deposit callose, and simulation of putative exocytotic voltage transients.

Pickard, B. G.

1985-01-01

97

Spontaneous tetraploidy in apomictic seedlings of Citrus  

Microsoft Academic Search

Populations of apomictic seedlings of clones ofCitrus species,Citrus hybrids, andPoncirus in the sub-family Aurantioideae were examined for spontaneous tetraploids as a source of materials for use in breeding experiments.\\u000a Diagnostic features found useful in identifying nucellar tetraploids were leaf shape, petiole blade shape, leaf blade thickness,\\u000a leaf color, comparative size differences in leaf venation, oil glands, and stomata, stem thickness,

H. C. Barrett; D. J. Hutchison

1978-01-01

98

Photocontrol of anthocyanin formation in turnip seedlings  

Microsoft Academic Search

The participation of the red\\/far-red reversible reaction of phytochrome in the control of anthocyanin formation in turnip seedlings has been demonstrated. A brief exposure to red light following a preliminary irradiation period in blue, increased anthocyanin content compared with blue alone; this effect was reversed by a subsequent short exposure to far-red. The sensitivity to red light was largely restricted

Renate Grill

1965-01-01

99

Kinetics for phototropic curvature by etiolated seedlings of Arabidopsis thaliana  

NASA Technical Reports Server (NTRS)

An infrared-imaging system has been used to study the influence of gravity on the kinetics of first positive phototropism. The development of phototropic curvature of etiolated seedlings of Arabidopsis thaliana was measured in the absence of visible radiation. Following a pulse of blue light, stationary seedlings curved to a maximum of approximately 16 degrees about 80 minutes after stimulation. The seedlings then curved upward again or straightened by about 6 degrees during the subsequent 100 minutes. Seedlings rotated on a clinostat reached a similar maximum curvature following photostimulation. These seedlings maintained that curvature for 30 to 40 minutes before subsequently straightening to the same extent as the stationary seedlings. It is concluded that straightening is not a consequence of gravitropism, although gravity has some effect on the phototropism kinetics.

Orbovic, V.; Poff, K. L.

1991-01-01

100

Photosynthetic responses of grafted bitter melon seedlings to flood stress  

Microsoft Academic Search

Young seedlings of bitter melon (Momordica charantia L. cv. New Known You #3) grafted onto luffa (Luffa cylindrica Roem. cv. cylinder #2) rootstocks were investigated for adaptation of photosynthetic activities under flooding conditions. Flooding treatment of grafted bitter melon seedlings reduced leaf photosynthetic rate, stomatal conductance, transpiration, soluble protein, and activity of ribulose-1,5-bisphosphate carboxylase\\/oxygenase (rubisco) as compared with control seedlings.

Chung Ta Liao; Chin Ho Lin

1996-01-01

101

Mechanical shock during transportation: effects on seedling performance  

Microsoft Academic Search

A study was carried out to monitor shocks to seedling planting stock during transport from nursery to the planting site in normal commercial reforestation operations. Size and exact time of mechanical shocks were measured by a recorder placed inside seedling boxes. Seedling shipments by refrigerated semi-trailer, 5-ton truck, pickup truck, small trailer and all-terrain vehicles were monitored in Alberta and

Ernst I. Stjernberg

1997-01-01

102

Microhabitat associations and seedling bank dynamics in a neotropical forest  

Microsoft Academic Search

We conducted a rigorous test of tropical tree seedling microhabitat differentiation by examining microhabitat associations, survival and growth of established seedlings of ten tropical tree species representing a four-factor gradient in seed size. Eight microhabitat variables describing soil and light conditions were measured directly adjacent to each of 588 seedlings within twelve 10×100 m belt transects at Paracou, French Guiana, and

Christopher Baraloto; Deborah E. Goldberg

2004-01-01

103

Habitat-related variation in seedling recruitment of Gentiana pannonica  

NASA Astrophysics Data System (ADS)

Differences in seedling recruitment of Gentiana pannonica were investigated between the primary (relict) and the secondary (semi-natural) forest-free habitats of the Bohemian Forest (870-1200 m a.s.l.) and of the Alps (1045-1935 m a.s.l.) to understand the factors promoting the seedling recruitment of G. pannonica and their importance for species distribution, population structure, and conservation. In the communities with adult plants of G. pannonica, we recorded environmental variables (the slope, the altitude, and the covers of bare ground, litter, and rocks), estimated parameters of the vegetation (the covers of herbs, bryophytes, and dwarf shrubs), and counted the seedlings of G. pannonica. In a field experiment, we investigated seedling survival under different soil moisture regimes. We also observed seasonal dynamics of seedling recruitment in permanent plots over the course of three years. In the primary habitats of both regions, G. pannonica grew in a relatively wide range of communities, and its seedlings occurred in each area. In the secondary habitats of the Bohemian Forest, a very low frequency of the seedlings was recorded. The number of seedlings increased with the covers of the moss layer and of bare soil and decreased with the cover of the herb layer, especially of graminoids. The seedling mortality was significantly lower in the plots with higher soil moistures, and the emergence of new-born seedlings was concentrated in the spring season, when the soil received a high water supply due to melting of snow. For the successful generative reproduction of G. pannonica, our findings highlight the critical importance of the microsites with low levels of competition and of sufficient soil moisture G. pannonica. It seems that because of the long-term lack of grazing disturbances, the structures of the secondary habitats of G. pannonica in the Bohemian Forest have become unfavourable for seedling establishment and generative reproduction of this threatened species.

Ekrtová, Ester; Košnar, Jan

2012-11-01

104

Ectomycorrhizal networks and seedling establishment during early primary succession.  

PubMed

Ectomycorrhizal (ECM) fungal mycelia are the main organs for nutrient uptake in many woody plants, and often connect seedlings to mature trees. While it is known that resources are shared among connected plants via common mycorrhizal networks (CMNs), the net effects of CMNs on seedling performance in the field are almost unknown. CMNs of individual ECM fungal species were produced in an early succession volcanic desert by transplanting current-year seedlings of Salix reinii with ECM mother trees that had been inoculated with one of 11 dominant ECM fungal species. Most seedlings were connected to individual CMNs without being infected by other ECM fungi. Although control seedlings showed poor growth under severe nutrient competition with larger nonmycorrhizal mother trees, nutrient acquisition and growth of seedlings connected to CMNs were improved with most fungal species. The positive effects of CMNs on seedling performance were significantly different among ECM fungal species; for example, the maximum difference in seedling nitrogen acquisition was 1 : 5.9. The net effects of individual CMNs in the field and interspecific variation among ECM fungal species are shown. PMID:16390428

Nara, Kazuhide

2006-01-01

105

Moss seedling and method of producing dense moss mat therefrom  

US Patent & Trademark Office Database

Plant tissues of mosses such as cut tissue pieces, gametophores, calluses, protonemata, spores, gemmae, subterranean stems or rhizoids are purely cultured in a culture medium to generate seedlings (cultigen) corresponding to plumules, and the seedlings are sown onto a nursery at a desired colony density, followed by appropriate caring.

1995-12-19

106

Factors Affecting Cold Injury of Sugarbeat Seedlings1  

Microsoft Academic Search

Sugarbeet seedlings (Beta vulgaris L.) may be killed by Spring frost just as they emerge from the soil. Possible solutions to this problem were investigated under closely controlled laboratory and growth chamber condi- tions. The seedlings were germinated at different tempera- tures in contact with solutions containing both varying osmotic pressures and compounds known to promote cold- hardiness in other

J. W. Cary

1975-01-01

107

Uptake of Seeds Secondary Metabolites by Virola surinamensis Seedlings.  

PubMed

The major secondary metabolites and fatty acids occurring in the seeds of Virola surinamensis were monitored by GC-MS during germination and seedling development. The role as carbon source for seedling development was indicated considering that both classes of compounds were similarly consumed in the seeds and that no selective consumption of compounds could be detected. PMID:22505921

Kato, Massuo Jorge; Yoshida, Massayoshi; Lopes, Norberto Peporine; da Silva, Denise Brentan; Cavalheiro, Alberto José

2012-01-01

108

Uptake of Seeds Secondary Metabolites by Virola surinamensis Seedlings  

PubMed Central

The major secondary metabolites and fatty acids occurring in the seeds of Virola surinamensis were monitored by GC-MS during germination and seedling development. The role as carbon source for seedling development was indicated considering that both classes of compounds were similarly consumed in the seeds and that no selective consumption of compounds could be detected.

Kato, Massuo Jorge; Yoshida, Massayoshi; Lopes, Norberto Peporine; da Silva, Denise Brentan; Cavalheiro, Alberto Jose

2012-01-01

109

The influence of ammonium on nitrate reduction in wheat seedlings  

Microsoft Academic Search

Ammonium markedly inhibited nitrate absorption by nitrogenstarved wheat seedlings but did not decrease the proportion of absorbed nitrate that was reduced. Seedlings high in nitrate (absorbed prior to the experimental periods) reduced similar amounts of this nitrate regardless of whether or not ammonium was present and being absorbed during the period of measurement. Ammonium or products of ammonium assimilation did

P. L. Minotti; Doris Craig Williams; W. A. Jackson

1969-01-01

110

Accumulation and speciation of vanadium in lycium seedling.  

PubMed

Lycium seedling was subjected to varying doses of V for 40-45 days to examine the effects on uptake, accumulation, and speciation of V in Lycium seedling by differential centrifugation and enzymolysis. V concentrations in Lycium seedling organs were in sequence as follows: root > leaf > stem. V uptake into stem and leaf were primarily combined with acid-soluble polar compounds, polysaccharide, and immobile materials on the cell walls. There were different speciations of V in root with different V stress levels. Enzymolysis results suggest that about 60 % of the V in Lycium seedling root was combined with pectin and cellulose. It is the antidotal effect of pectin and cellulose in the cell wall that reduced the V damage to Lycium seedling. PMID:24859852

Hou, Ming; Lu, Chang; Wei, Kexiang

2014-06-01

111

Particulate Cytochromes of Mung Bean Seedlings 1  

PubMed Central

Efforts have been made to solubilize cytochrome components from particulate fractions of etiolated mung bean seedlings. Low temperature spectrophotometry reveals that the cytochrome composition of mitochondria isolated from whole seedlings is the same as that reported by Bonner for mung bean hypocotyls. On the basis of the identity in position of the ?-bands in low temperature difference spectra for mitochondria, for a partially purified haemoprotein from mitochondria, and for purified cytochrome b-555, it is suggested that cytochrome b-555 is an intrinsic component of mung bean mitochondria. Difference spectra show that both the mitochondrial and microsomal fractions contain at least 2 b-type cytochromes. Cytochrome b-555 is almost certainly present in the microsomes, since the low temperature difference spectrum for the cytochrome is identical with the spectrum for this particulate fraction. By freezing and thawing mung bean mitochondria in 4% cholate and centrifuging, cytochrome oxidase activity can be concentrated in the supernatant fraction, although it is not completely solubilized. The oxidase is inhibited by high concentrations of cytochrome c. A particle-bound cytochrome c can be obtained from mitochondria by digestion with snake venom. However, the autoxidizability of the preparation indicates that the cytochrome has been solubilized in a modified form. A CO-binding pigment can be obtained from mung bean microsomes by digestion with snake venom.

Kasinsky, Harold E.; Shichi, Hitoshi; Hackett, David P.

1966-01-01

112

Subamolide B Isolated from Medicinal Plant Cinnamomum subavenium Induces Cytotoxicity in Human Cutaneous Squamous Cell Carcinoma Cells through Mitochondrial and CHOP-Dependent Cell Death Pathways  

PubMed Central

Subamolide B is a butanolide isolated from Cinnamomum subavenium, a medicinal plant traditionally used to treat various ailments including carcinomatous swelling. We herein reported for the first time that subamolide B potently induced cytotoxicity against diverse human skin cancer cell lines while sparing nonmalignant cells. Mechanistic studies on human cutaneous squamous cell carcinoma (SCC) cell line SCC12 highlighted the involvement of apoptosis in subamolide B-induced cytotoxicity, as evidenced by the activation of caspases-8, -9, -4, and -3, the increase in annexin V-positive population, and the partial restoration of cell viability by cotreatment with the pan-caspase inhibitor z-VAD-fmk. Additionally, subamolide B evoked cell death pathways mediated by FasL/Fas, mitochondria, and endoplasmic reticulum (ER) stress, as supported by subamolide B-induced FasL upregulation, BCL-2 suppression/cytosolic release of cytochrome c, and UPR activation/CHOP upregulation, respectively. Noteworthy, ectopic expression of c-FLIPL or dominant-negative mutant of FADD failed to impair subamolide B-induced cytotoxicity, whereas BCL-2 overexpression or CHOP depletion greatly rescued subamolide B-stimulated cells. Collectively, these results underscored the central role of mitochondrial and CHOP-mediated cell death pathways in subamolide B-induced cytotoxicity. Our findings further implicate the potential of subamolide B for cutaneous SCC therapy or as a lead compound for developing novel chemotherapeutic agents.

Yang, Shu-Yi; Wang, Hui-Min; Wu, Tai-Wen; Chen, Yi-Ju; Shieh, Jeng-Jer; Lin, Ju-Hwa; Ho, Tsing-Fen; Luo, Ren-Jie; Chen, Chung-Yi; Chang, Chia-Che

2013-01-01

113

In vitro effect of essential oils from Cinnamomum aromaticum, Citrus limon and Allium sativum on two intestinal flagellates of poultry, Tetratrichomonas gallinarum and Histomonas meleagridis.  

PubMed

Essential oils may be effective preventive or curative treatments against several flagelated poultry parasites and may become primordial either to organic farms, or as more drugs are bannished. The anti-flagellate activity of essential oils obtained from fresh leaves of Cinnamomum aromaticum, Citrus limon pericarps and Allium sativum bulbs was investigated in vitro on Tetratrichomonas gallinarum and Histomonas meleagridis. On T. gallinarum, the minimal lethal concentration (MLC) at 24 hours was 0.25 microliter/ml for C. aromaticum oil, and 0.125 microliter/ml for C. limon and A. sativum oils. On H. meleagridis, MLC was 0.5 microliter/ml for C. aromaticum oil and 1 microliter/ml for C. limon and A. sativum oils at 24 and 48 hours. Moreover, no synergistic effects were evidenced in vitro. The essential oil constituents, based on their GC retention times have been also identified. The major component is trans-cinnamaldehyde (79%) for C. aromaticum; limonene for C. limon (71%) and diallyl tri- and disulfide (79%) for A. sativum. Even if concentration and protocol adaptations are required for successful in vivo treatments, it appears that these oils may be useful as chemotherapeutic agents against several poultry parasites. PMID:12847923

Zenner, L; Callait, M P; Granier, C; Chauve, C

2003-06-01

114

Identification of compounds from the water soluble extract of Cinnamomum cassia barks and their inhibitory effects against high-glucose-induced mesangial cells.  

PubMed

The difficulty of diabetic nephropathy (DN) treatment makes prevention the best choice. Cinnamomum cassia barks, known as Chinese cinnamon or Chinese cassia, is one of the most popular natural spices and flavoring agents in many parts of the World. Since previous reports indicated that Chinese cinnamon extract could be used for the treatment of diabetes, we proposed that this spice may be beneficial for the prevention of DN. However, the responsible compounds need to be further identified. In this study, we isolated three new phenolic glycosides, cinnacassosides A-C (1-3), together with fifteen known compounds from the water soluble extract of Chinese cinnamon. The structures of the new compounds were identified by comprehensive spectroscopic evidence. Eleven compounds (6-9, 11, 13-18) were isolated from this spice for the first time, despite extensive research on this species in the past, which added new facets for the chemical profiling of this spice. These isolates were purposely evaluated for their inhibitory effects on IL-6 and extracellular matrix production in mesangial cells which are definitely implicated in DN. The results showed that compounds 4-8 could inhibit over secretion of IL-6, collagen IV and fibronectin against high-glucose-induced mesangial cells at 10 mM, suggesting that Chinese cinnamon could be used as a functional food against DN. PMID:24013407

Luo, Qi; Wang, Shu-Mei; Lu, Qing; Luo, Jie; Cheng, Yong-Xian

2013-01-01

115

Effects of flooding regime and seedling treatment on early survival and growth of nuttall oak  

USGS Publications Warehouse

Effects of flooding on survival and growth of three different types of Nuttall oak (Quercus texana Buckl.) seedlings were observed at the end of third and fifth growing seasons at Yazoo National Wildlife Refuge, Mississippi, U.S.A. Three types of seedlings were planted in January 1995 in a split-plot design, with four replications at each of two elevations on floodprone, former cropland in Sharkey clay soil. The lower of the two planting elevations was inundated for 21 days during the first growing season, whereas the higher elevation did not flood during the 5-year period of this study. The three types of 1-0 seedlings were bareroot seedlings, seedlings grown in containers (3.8 ?? 21a??cm plastic seedling cones), and container-grown seedlings inoculated with vegetative mycelia of Pisolithus tinctorius (Pers.) Coker. Survival of all the three seedling types was greatest at the lower, intermittently flooded elevation, indicating that drought and related effects on plant competition were more limiting to seedling survival than flooding. At the lower elevation, survival of mycorrhizal-inoculated container seedlings was greater than that of noninoculated container seedlings. Survival among bareroot seedlings and inoculated container seedlings was not significantly different at either elevation. At the higher, nonflooded elevation, however, bareroot seedling survival was greater than the survival of container seedlings without inoculation. Differences were significant among the inoculated and the noninoculated container seedlings, with higher survival of inoculated seedlings at both elevations, though differences were only significant in year 3. At the end of the fifth year, height of bareroot seedlings was significantly greater than the heights of both types of container-grown seedlings at both planting elevations. Because seedlings grown in the plastic seedlings cones did not survive better than the bareroot seedlings at either planting elevation, the bareroot stock appear to be the economically superior choice for regeneration in Sharkey soil.

Burkett, V.R.; Draugelis-Dale, R.O.; Williams, H.M.; Schoenholtz, S.H.

2005-01-01

116

Variation in drought response of sal (Shorea robusta) seedlings.  

PubMed

Plant development and distribution in areas with seasonal rainfall are often related to the ability of plants to postpone desiccation or tolerate low water potentials during drought. Regeneration of Shorea robusta Gaertn. (sal), a commercially valuable, widely distributed tree of the Indian tropical belt, is unsuccessful at the base of the Himalaya. Seedling shoots die back repeatedly during the long drought that follows the monsoon rain. During the course of one year, we monitored changes in plant and soil water potentials (Psi), leaf conductance (gw), osmotic and elastic adjustment, and xylem conductance of sal seedlings of different sizes from three landforms: an alluvial plain at 540 m elevation, a slope at 510 m, and a montane site at 1370 m. Predawn plant Psi and gw were lowest in the smallest seedlings (< 20 cm tall). Across sites and seasons, seedlings > 100 cm tall had higher morning gw than seedlings in the other size classes. In all size classes, plant Psi was lowest during early summer, when leafing begins. Among sites, Psi and gw were lowest in seedlings at the montane site. Osmotic potential was lowest during leaf development and highest during the rainy season, and tissue elasticity was highest during winter. As leaf area increased during leaf development, xylem conductance per unit of xylem cross-sectional area also increased. We conclude that low Psi is unlikely to be a major cause of seedling mortality. Small seedlings, with low Psi, had low leaf conductance. Adjustments of osmotic and elastic properties appear to aid responses of seedlings to drought. PMID:12975126

Garkoti, Satish C; Zobel, Donald B; Singh, Surendra P

2003-10-01

117

Boron nutrition affects the carbon metabolism of silver birch seedlings.  

PubMed

Boron (B) is an essential micronutrient whose deficiency is common both in agriculture and in silviculture. Boron deficiency impairs the growth of plants and affects many metabolic processes like carbohydrate metabolism. Boron deficiency and also excess B may decrease the sink demand by decreasing the growth and sugar transport which may lead to the accumulation of carbohydrates and down-regulation of photosynthesis. In this study, we investigated the effects of B nutrition on the soluble and storage carbohydrate concentrations of summer leaves and autumn buds in a deciduous tree species, Betula pendula Roth. In addition, we investigated the changes in the pools of condensed tannins between summer and autumn harvests. One-year-old birch seedlings were fertilized with a complete nutrient solution containing three different levels of B: 0, 30 and 100% of the standard level for complete nutrient solution. Half of the seedlings were harvested after summer period and another half when leaves abscised. The highest B fertilization level (B100) caused an accumulation of starch and a decrease in the concentrations of hexoses (glucose and fructose) in summer leaves, whereas in the B0 seedlings, hexoses (mainly glucose) accumulated and starch decreased. These changes in carbohydrate concentrations might be related to the changes in the sink demand since the autumn growth was the smallest for the B100 seedlings and largest for the B30 seedlings that did not accumulate carbohydrates. The autumn buds of B30 seedlings contained the lowest levels of glucose, glycerol, raffinose and total polyols, which was probably due to the dilution effect of the deposition of other substances like phenols. Condensed tannins accumulated in high amounts in the birch stems during the hardening of seedlings and the largest accumulation was detected in the B30 treatment. Our results suggest that B nutrition of birch seedlings affects the carbohydrate and phenol metabolism and may play an important role in the hardening process of the seedlings. PMID:22084021

Ruuhola, Teija; Keinänen, Markku; Keski-Saari, Sarita; Lehto, Tarja

2011-11-01

118

Growth of ponderosa pine seedlings as affected by air pollution  

NASA Astrophysics Data System (ADS)

The effect of air pollution on seedling survival and competitive ability is important to natural and artificial regeneration of forest trees. Although biochemical and physiological processes are sensitive indicators of pollution stress, the cumulative effects of air pollutants on seedling vigor and competitive ability may be assessed directly from whole-plant growth characteristics such as diameter, height, and photosynthetic area. A few studies that have examined intraspecific variation in seedling response to air pollution indicate that genotypic differences are important in assessing potential effects of air pollution on forest regeneration. Here, we studied the effects of acid rain (no-rain, pH 5.1 rain, pH 3.0 rain) and ozone (filtered, ambient, twice-ambient) in the field on height, diameter, volume, the height:diameter ratio, maximum needle length, and time to reach maximum needle length in seedlings of three families of ponderosa pine ( Pinus ponderosa Dougl. ex Laws). Seedling diameter, height, volume, and height:diameter ratio related significantly to their pre-treatment values. Twice-ambient ozone decreased seedling diameter compared with ozone-filtered air. A significant family-by-ozone interaction was detected for seedling height, as the height of only one of the three families was decreased by twice-ambient ozone compared with the ambient level. Seedling diameter was larger and the height:diameter ratio was smaller under pH 3.0 rain compared to either the no-rain or the pH 5.1-rain treatment. This suggests greater seedling vigor, perhaps due to a foliar fertilization effect of the pH 3.0 rain.

Momen, B.; Anderson, P. D.; Houpis, J. L. J.; Helms, J. A.

119

Arthropod invasion disrupts Cycas micronesica seedling recruitment.  

PubMed

We recently described characteristics of reproductive effort for the cycad Cycas micronesica on the island of Guam. The data were serendipitously recorded just prior to the devastating invasion of the armored scale Aulacaspis yasumatsui. This invasion decimated the cycad population and after six years of infestation no recruitment is occurring among the survivors. We describe various underlying mechanisms that may explain how this homopteran insect has eliminated host recruitment among categories including plant-pollinator mutualism disruptions, direct damage to reproductive structures, population level responses to declining plant health, and failures of seedlings to establish. Our pre-invasion data on reproductive effort will serve as the benchmark for quantifying how this alien pest is endangering the endemic cycad. PMID:22446554

Marler, Thomas E; Terry, L Irene

2011-11-01

120

Economical and Simple Production of Containerized Hardwood Seedlings.  

National Technical Information Service (NTIS)

An automatic mat-watering system for growing hardwood seedlings in containers was designed and tested. The system has only one moving part, and no electrical requirements. There is no need to calculate different watering schedules for different growth pha...

M. C. Hoyle

1982-01-01

121

In vitro antifungal, anti-elastase and anti-keratinase activity of essential oils of Cinnamomum-, Syzygium- and Cymbopogon-species against Aspergillus fumigatus and Trichophyton rubrum.  

PubMed

This study was aimed to evaluate effects of certain essential oils namely Cinnamomum verum, Syzygium aromaticum, Cymbopogon citratus, Cymbopogon martini and their major components cinnamaldehyde, eugenol, citral and geraniol respectively, on growth, hyphal ultrastructure and virulence factors of Aspergillus fumigatus and Trichophyton rubrum. The antifungal activity of essential oils and their major constituents was in the order of cinnamaldehyde>eugenol>geraniol=C. verum>citral>S. aromaticum>C. citratus>C. martini, both in liquid and solid media against T. rubrum and A. fumigatus. Based on promising antifungal activity of eugenol and cinnamaldehyde, these oils were further tested for their inhibitory activity against ungerminated and germinated conidia in test fungi. Cinnamaldehyde was found to be more active than eugenol. To assess the possible mode of action of cinnamaldehyde, electron microscopic studies were conducted. The observations revealed multiple sites of action of cinnamaldehyde mainly on cell membranes and endomembranous structures of the fungal cell. Further, test oils were also tested for their anti-virulence activity. More than 70% reduction in elastase activity was recorded in A. fumigatus by the oils of C. verum, C. martini, eugenol, cinnamaldehyde and geraniol. Similar reduction in keratinase activity in A. niger was recorded for the oils of C. martini and geraniol. Maximum reduction (96.56%) in elastase activity was produced by cinnamaldehyde whereas; geraniol caused maximum inhibition (97.31%) of keratinase activity. Our findings highlight anti-elastase and anti-keratinase activity of above mentioned essential oils as a novel property to be exploited in controlling invasive and superficial mycoses. PMID:21893402

Khan, Mohd Sajjad Ahmad; Ahmad, Iqbal

2011-12-15

122

GC-MS analysis and screening of antidiabetic, antioxidant and hypolipidemic potential of Cinnamomum tamala oil in streptozotocin induced diabetes mellitus in rats  

PubMed Central

Aim of the study This study was made to investigate the antidiabetic, antioxidant and hypolipidemic potential of Cinnamomum tamala, (Buch.-Ham.) Nees & Eberm (Tejpat) oil (CTO) in streptozotocin (STZ) induced diabetes in rats along with evaluation of chemical constituents. Materials and methods The GC-MS (Gas chromatography–mass spectrometry) analysis of the oil showed 31 constituents of which cinnamaldehyde was found the major component (44.898%). CTO and cinnamaldehyde was orally administered to diabetic rats to study its effect in both acute and chronic antihyperglycemic models. The body weight, oral glucose tolerance test and biochemical parameters viz. glucose level, insulin level, liver glycogen content, glycosylated hemoglobin, total plasma cholesterol, triglyceride and antioxidant parameters were estimated for all treated groups and compared against diabetic control group. Results CTO (100?mg/kg and 200?mg/kg), cinnamaldehyde (20?mg/kg) and glibenclamide (0.6?mg/kg) in respective groups of diabetic animals administered for 28?days reduced the blood glucose level in streptozotocin induced diabetic rats. There was significant increase in body weight, liver glycogen content, plasma insulin level and decrease in the blood glucose, glycosylated hemoglobin and total plasma cholesterol in test groups as compared to control group. The results of CTO and cinnamaldehyde were found comparable with standard drug glibenclamide. In vitro antioxidant studies on CTO using various models showed significant antioxidant activity. In vivo antioxidant studies on STZ induced diabetic rats revealed decreased malondialdehyde (MDA) and increased reduced glutathione (GSH). Conclusion Thus the investigation results that CTO has significant antidiabetic, antioxidant and hypolipidemic activity.

2012-01-01

123

Apoptosis in wheat seedlings grown under normal daylight.  

PubMed

Apoptosis was observed in the coleoptile and initial leaf in 5-8-day-old wheat seedlings grown under normal daylight. Apoptosis is an obligatory event in early wheat plant ontogenesis, and it is characterized by cytoplasmic structural reorganization and fragmentation, in particular, with the appearance in vacuoles of specific vesicles containing intact organelles, chromatin condensation and margination in the nucleus, and internucleosomal fragmentation of nuclear DNA. The earliest signs of programmed cell death (PCD) were observed in the cytoplasm, but the elements of apoptotic degradation in the nucleus appeared later. Nuclear DNA fragmentation was detected after chromatin condensation and the appearance in vacuoles of specific vesicles containing mitochondria. Two PCD varieties were observed in the initial leaf of 5-day-old seedlings grown under normal daylight: a proper apoptosis and vacuolar collapse. On the contrary, PCD in coleoptiles under various growing (light) conditions and in the initial leaf of etiolated seedlings is only a classical plant apoptosis. Therefore, various tissue-specific and light-dependent PCD forms do exist in plants. Amounts of O2*- and H2O2 evolved by seedlings grown under normal daylight are less than that evolved by etiolated seedlings. The amount of H2O2 formed in the presence of sodium salicylate or azide by seedlings grown under normal daylight was increased. Contrary to etiolated seedlings, the antioxidant BHT (ionol) did not inhibit O2*- formation and apoptosis and it had no influence on ontogenesis in the seedlings grown under normal daylight. Thus, in plants grown under the normal light regime the powerful system controlling the balance between formation and inactivation of reactive oxygen species (ROS) does exist and it effectively functions. This system is responsible for maintenance of cell homeostasis, and it regulates the crucial ROS level controlling plant growth and development. In etiolated plants, this system seems to be absent, or it is much less effective. PMID:15061695

Aleksandrushkina, N I; Zamyatnina, V A; Bakeeva, L E; Seredina, A V; Smirnova, E G; Yaguzhinsky, L S; Vanyushin, B F

2004-03-01

124

Accumulation of Sugars in Barley Seedlings on Very Acid Soil  

Microsoft Academic Search

FOR a number of years it has been noticed at Woburn that seedling barley plants sown in soil too acid to allow normal growth (pH 4.3 or thereabouts) were very much more attractive to small birds (chaffinches and the like) than similar seedlings grown on a normal soil (pH 6.0-6.5) and that consequently a very large proportion of the growing

T. W. Barnes

1945-01-01

125

Actin of Beta vulgaris seedlings under the clinorotation  

NASA Astrophysics Data System (ADS)

We study the influence of altered gravity on actin expression in roots of Beta vulguris seedlings grown on the horizontal clinostat (2 rpm) from seed germination for three days. It is shown that the total actin quantity was not influenced. Three actin isoforms are revealed; a relative protein quantity of these isoforms was similar both in clinorotated seedlings and in ones grown in norm. This point to stable expression of actin under the altered gravity conditions.

Kozeko, L. Ye.

126

[Growth of epiphytic and soil yeasts on wheat seedlings].  

PubMed

Colonization of wheat seedlings by epiphytic (Rhodotorula glutinis) and soil (Lipomyces starkeyi) yeasts was studied by scanning electron microscopy. Epiphytic yeast cells dominated on the plant surface. Soil yeast cells were randomly distributed among both the zones of a seedling and the particles of an inorganic substrate. It has been found that epiphytic yeast strains can readily grow on the surface of a plant. PMID:561879

Guzeva, I S; Guzev, V S; Bab'eva, I P; Zviagintsev, D G

1977-01-01

127

Streamflow requirements for cottonwood seedling recruitment—An integrative model  

Microsoft Academic Search

This paper describes the ‘recruitment box,’ an integrative model that defines the stream stage patterns that enable successful\\u000a establishment of riparian cottonwood seedlings. In western North America, cottonwood seed dispersal generally occurs after\\u000a annual peak river flows. The receding stream exposes moist sites upon which seeds land after transport by wind and water.\\u000a Germination is rapid, and initial seedling establishment

John M. Mahoney; Stewart B. Rood

1998-01-01

128

Seed and seedling morphology of two species of Euphorbia (Euphorbiaceae)  

Microsoft Academic Search

Morphology of the seeds and seedlings ofEuphorbia hirta andE. thymifolia are described. In both the species, the seeds are endospermous, exotegmic, more or less oblong and obtusely tetragonal. The\\u000a testa is only two-layer thick, collapsing when dry; the tegmen is made up of a single layer of macrosclereids with occluded\\u000a lumen. The early developmental pattern of the seedlings in both

Jose K Mangaly; K Swarupanandan; P V Madhusoodan

1979-01-01

129

Recruitment of Thalassia testudinum seedlings into physically disturbed seagrass beds  

Microsoft Academic Search

Thalassia testudinum seedling recruitment, survival, and growth were examined within physically disturbed seagrass beds in the Florida Keys. Two separate studies were conducted. In the first, a large-scale study, T. testudinum seedlings were surveyed and collected from a large seagrass disturbance (1560 m 2 ), 4.8 yr after the initial impact from a motor-vessel grounding. In the second, a smaller-scale

Paula E. Whitfield; W. Judson Kenworthy; Michael J. Durako; Kamille K. Hammerstrom; Manuel F. Merello

2004-01-01

130

Influence of ozone on cold acclimation in sugar maple seedlings.  

PubMed

During summer 1994, sugar maple (Acer saccharum Marsh.) seedlings were grown in open-top chambers supplied with air containing near ambient ozone concentration (control, low O(3)) or three times the ambient ozone concentration (high O(3)). The rate of CO(2) assimilation was significantly reduced by chronic exposure to a high concentration of ozone during the summer. During fall, seedlings were removed from the open-top chambers and acclimated to cold under natural conditions. In both species during cold acclimation, the starch concentration decreased, whereas the sucrose concentration increased. There was no treatment effect on the freezing tolerance of roots, even though roots in the high-O(3) treatment accumulated higher concentrations of the cryoprotective oligosaccharides raffinose and stachyose than control roots. Cold acclimation occurred earlier and stachyose concentration of stems was higher in high-O(3)-treated seedlings than in low-O(3)-treated seedlings. Cold acclimation was associated with an earlier accumulation of ABA in the xylem sap of high-O(3)-treated seedlings compared with low-O(3)-treated seedlings. PMID:12651543

Bertrand, Annick; Robitaille, Gilles; Nadeau, Paul; Castonguay, Yves

1999-07-01

131

Seedling establishment of late colonizer is facilitated by seedling and overstory of early colonizer in a post-mined peatland  

Microsoft Academic Search

The seedling establishment of late colonizer may be promoted in the environments created by the early colonizer without interspecific\\u000a seedling competition. To confirm the hypothesis, seed-sowing experiments were conducted in a post-mined peatland, northern\\u000a Japan. Seeds on three grasses (Rhynchospora alba, Moliniopsis japonica and Phragmites australis) were sown in four vegetation sites: bareground, R. alba grassland, M. japonica grassland, and

Chika Egawa; Shiro Tsuyuzaki

2011-01-01

132

Lignification in young plant seedlings grown on earth and aboard the Space Shuttle  

NASA Technical Reports Server (NTRS)

The Space Shuttle era has provided an opportunity for investigators to conduct experiments in a microgravity environment. Two Shuttle flights, STS-3 and STS-51F, each contained an experiment designed principally to determine whether young plant seedlings exposed to microgravity had reduced lignin content in comparison to seedlings grown at one gravity. Three different plant species, pine, oats, and mung beans, were exposed for eight days to the microgravity environment of the Shuttle. The lignin content of in-flight seedlings was less than the control seedlings in all seven sets of seedlings included in these two experiments. In five sets of seedlings, the reduction in lignin content in flight seedlings ranged from 6 to 24 percent and was statistically significant. In addition, the activity of two enzymes involved in lignin synthesis, phenylalanine ammonia lyase and peroxidase, were significantly reduced in pine seedlings. It was therefore concluded that microgravity, as perceived by young plant seedlings, results in reduced lignin synthesis.

Cowles, Joe R.; Lemay, R.; Jahns, G.; Scheld, W. H.; Peterson, C.

1989-01-01

133

Beneficial effect of spider presence on seedling recruitment of the tropical rainforest tree Dipteryx oleifera (Fabaceae).  

PubMed

This research presents evidence showing that: (1) lower arthropod herbivory correlates with seedling survival, and (2) spider presence correlates with lower arthropod herbivory, seedling growth, and seedling survival of the tropical rainforest tree species Dipteryx oleifera in eastern Nicaragua. The study was conducted from January 2005 to January 2006 in a 6.37 ha permanent plot established in 2002. Seedling height, spider behavior and presence on seedlings, and percentage of leaf area lost due to arthropod herbivory were measured. Arthropod herbivory was assessed from digital photographs of each seedling within the permanent plot. Seedling fate was followed in order to determine its correlation with spider presence, initial seedling size, and arthropod herbivory. A GLM showed that seedling survival correlated negatively with lower levels of arthropod herbivory (<20%), while seedlings with higher levels of herbivore damage experienced mortalities close to 100%. Results from another GLM suggests that seedling mean height (aprox. 8 cm) would be increased by approximately 1.5 cm for each year that spiders were present on seedlings and would be decreased 0.75 cm in height for each percent unit of arthropod herbivory. We also report a trend toward lower arthropod herbivory in seedlings colonized by spiders with aggressive traits, presumably because more aggressive spiders better defended seedlings against herbivorous arthropods than less aggressive spiders. PMID:19928475

Ruiz, Javier; Ingram-Flóres, Cherryl; Boucher, Douglas H; Chaves, Luis F

2009-09-01

134

Cytokinins in Seedling Roots of Pea  

PubMed Central

The natural occurrence of cytokinins existing both in a free form and as a constituent of transfer RNA was examined in serial segments of young seedling roots of pea. Purified ethanol extracts of root apices were resolved into four factors capable of inducing soybean callus tissue proliferation. The most active factor was identified as zeatin or some closely related compound; it produced polyploid divisions and tracheary element differentiation when tested on cultured pea root segments. The terminal 0- to 1-millimeter root tip contained 43 to 44 times more free cytokinin on a fresh weight or a per cell basis than the next 1- to 5-millimeter root segment. Extracts of more proximal segments behind the tip contained no measurable free cytokinin. Acid hydrolysates of transfer RNA exhibited reproducible cytokinin activity. Bioassays revealed that the predominant amounts of free cytokinin and that present in transfer RNA were restricted to the extreme root tip. There was approximately 27 times more free cytokinin than the amount detected in transfer RNA in root apices.

Short, Keith C.; Torrey, John G.

1972-01-01

135

Hydroxamic Acid Glucosyltransferases from Maize Seedlings 1  

PubMed Central

Hydroxamic acids occur in several forms in maize (Zea mays L.) with 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA) being the predominant form and others including 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA) being found at lower concentrations. Two enzymes capable of glucosylating hydroxamic acids were identified in maize protein extracts and partially purified and characterized. The total enzyme activity per seedling increased during the first 4 days of germination and was concurrent with the accumulation of DIMBOA. Purification of the enzymes by ammonium sulfate precipitation followed by Sephadex G-200 and Q-Sepharose gel chromatography resulted in a 13-fold increase in specific activity. The enzymes are initially separated into two peaks (peak 1 and peak 2) of activity by Q-Sepharose gel chromatography. The peak 1 glucosyltransferase had 3.6% of the DIMBOA glucosylating activity when DIBOA was used as substrate, whereas this percentage increased to 57% for the peak 2 enzyme. The enzyme in peak 2 has a Km of 174 micromolar for DIMBOA and a Km of 638 micromolar for DIBOA; the enzyme in peak 1 has a Km of 217 micromolar for DIMBOA and its activity on DIBOA was too low to determine a Km. The identification of two glucosyltransferases capable of glucosylating hydroxamic acids in vitro serves as an initial step in the characterization of the enzymes involved in production of hydroxamic acids in maize.

Bailey, Bryan A.; Larson, Russell L.

1989-01-01

136

Starch bioengineering affects cereal grain germination and seedling establishment  

PubMed Central

Cereal grain germination is central for plant early development, and efficient germination has a major role in crop propagation and malting. Endosperm starch is the prime energy reserve in germination and seedling establishment. In this study, it was hypothesized that optimized starch granule structure, and not only the endosperm starch content per se, is important for germination and seedling establishment. For that purpose, wild-type (WT), and specifically engineered degradable hyperphosphorylated (HP) starch and more resistant amylose-only (AO) starch barley lines were used. The transgenics showed no severe phenotypes and the WT and HP lines degraded the starch similarly, having 30% residual starch after 12 d of germination. However, the AO line showed significant resistance to degradation, having 57% residual starch. Interestingly, protein and ?-glucan (BG) degradation was stimulated for both HP and AO lines as compared with the WT. At late seedling establishment stages, specific sugars were rapidly consumed in the AO line. ?-Amylase activity was distinctly suppressed in both the HP and the AO lines. Pre-germination ?-amylase deposition was low in the AO grains and ?-amylase was generally suppressed in both HP and AO lines throughout germination. As further supported by scanning electron microscopy and histochemical analyses on grain and seedlings, it was concluded that inadequate starch granule deposition in combination with the suppressed hydrolase activity leads to temporal and compensating re-direction of starch, sugar, and protein catabolism important to maintain metabolic dynamics during grain germination and seedling establishment.

Hebelstrup, Kim H.; Blennow, Andreas

2014-01-01

137

Endophytic Chaetomium globosum enhances maize seedling copper stress tolerance.  

PubMed

This study aims at characterisation of the impact of Chaetomium globosum on copper stress resistance of maize seedlings. Higher levels of copper treatment decreased maize dry weight and induced a marked increase in osmotic solutes, antioxidant enzyme activity and the level of lipid peroxidation. On the other hand, addition of the endophytic C. globosum alleviated the toxic effect of copper on maize growth. The combination of copper sulphate and Chaetomium increased seedling dry weight, osmotic solute content and antioxidant enzyme activity compared to copper sulphate alone, while lipid peroxidation levels were also decreased. The fungal scavenger system might be important for supporting the ability of maize seedlings to resist copper toxicity. PMID:22672065

Abou Alhamed, M F; Shebany, Y M

2012-06-01

138

Endophytic fungi reduce leaf-cutting ant damage to seedlings  

PubMed Central

Our study examines how the mutualism between Atta colombica leaf-cutting ants and their cultivated fungus is influenced by the presence of diverse foliar endophytic fungi (endophytes) at high densities in tropical leaf tissues. We conducted laboratory choice trials in which ant colonies chose between Cordia alliodora seedlings with high (Ehigh) or low (Elow) densities of endophytes. The Ehigh seedlings contained 5.5 times higher endophyte content and a greater diversity of fungal morphospecies than the Elow treatment, and endophyte content was not correlated with leaf toughness or thickness. Leaf-cutting ants cut over 2.5 times the leaf area from Elow relative to Ehigh seedlings and had a tendency to recruit more ants to Elow plants. Our findings suggest that leaf-cutting ants may incur costs from cutting and processing leaves with high endophyte loads, which could impact Neotropical forests by causing variable damage rates within plant communities.

Bittleston, L. S.; Brockmann, F.; Wcislo, W.; Van Bael, S. A.

2011-01-01

139

Effects of Defoliation and Drought on Root Food Reserves in Sugar Maple Seedlings.  

National Technical Information Service (NTIS)

The root food reserves and starch levels in defoliated sugar maple seedlings were lower than in undefoliated controls. Unwatered seedlings did not have significantly lower root food reserves than watered controls. Starch levels were lower and glucose and ...

J. Parker

1970-01-01

140

Microhabitat associations and seedling bank dynamics in a neotropical forest.  

PubMed

We conducted a rigorous test of tropical tree seedling microhabitat differentiation by examining microhabitat associations, survival and growth of established seedlings of ten tropical tree species representing a four-factor gradient in seed size. Eight microhabitat variables describing soil and light conditions were measured directly adjacent to each of 588 seedlings within twelve 10x100 m belt transects at Paracou, French Guiana, and at 264 reference points along the transects. From these measurements, we defined three principal components describing soil richness, soil softness and canopy openness. Six of ten species (in 9 of 30 total cases) were distributed non-randomly with respect to microhabitat along at least one principal component. However, few species demonstrated clear microhabitat specialization. All shifts in distribution relative to reference points were in the same direction (richer, softer soil). Furthermore, of 135 pairwise comparisons among the species, only 7 were significantly different. More than three-fourths of all seedlings (75.3%) survived over the 2-year monitoring period, but survival rates varied widely among species. In no case was the probability of survival influenced by any microhabitat parameter. Relative height growth rates for the seedlings over 2 years varied from -0.031 cm cm(-1) year(-1) (Dicorynia guianensis, Caesalpiniaceae) to 0.088 cm cm(-1) year(-1) (Virola michelii, Myristicaceae). In only 4 of 30 cases was height growth significantly associated with one of the three principal components. Because the conditions in this study were designed to maximize the chance of finding microhabitat differentiation among a group of species differing greatly in life history traits, the lack of microhabitat specialization it uncovered suggests that microhabitat partitioning among tropical tree species at the established seedling stage is unlikely to contribute greatly to coexistence among these species. PMID:15309615

Baraloto, Christopher; Goldberg, Deborah E

2004-12-01

141

The impact of ‘available area’ onArtemisia tridentata seedling dynamics  

Microsoft Academic Search

Seedling survival ofArtemisia tridentata ssp.tridentata (basin big sagebrush) was studied during 1984 and 1986 on a semi-arid rangeland in central Utah, USA. Seedlings were mapped in ungrazed pastures and observed on a 10 day interval for survival. Available resource area around individual seedlings was calculated using Theissen polygons. Over 90% of the naturally-occurring seedlings occurred in polygons of 150 mm2

M. K. Owens; B. E. Norton

1989-01-01

142

Protecting red oak seedlings with tree shelters in northwestern Pennsylvania. Forest Service research paper (Final)  

SciTech Connect

The report examines the growth and survival of planted and natural red oak seedlings and seedlings from planted acorns within translucent tan tree shelters, fences, and unprotected controls under a shelterwood seed-cut stand. Seedlings planted within tree shelters and fences were inside tree shelters. Natural seedlings grew very little and their height inside and outside of tree shelters did not differ. Recommendations based on these results should improve results from the use of tree shelters.

Walters, R.S.

1993-10-01

143

Seedling emergence, growth, and mineral concentration of three citrus rootstocks under salt stress  

Microsoft Academic Search

Salt tolerance of Carrizo citrange (CC), sour orange (SO), and Cleopatra mandarin (CM) rootstocks during emergence and early seedling stage of development was studied under greenhouse conditions. Increasing salt concentration in the nutrient solution delayed and depressed seedling emergence (SE), increased time to 50% emergence, reduced seedling growth (SD) but did not affect emergence spread. At the first salinity level

Mongi Zekri

1993-01-01

144

Seedling Quality Standards for Bottomland Hardwood Afforestation in the Lower Mississippi River Alluvial Valley: Preliminary Results  

Microsoft Academic Search

Afforestation of bottomland hardwood species has increased in the Lower Mississippi River Alluvial Valley (LMRAV) in recent years. Rising demand for hardwood nursery stock and poor performance of some planted seedlings has created concern regarding the quality of seedlings currently available for afforestation in the LMRAV. Furthermore, no definitive guidelines for optimal seedling morphological quality of bottomland hardwoods in the

Douglass F. Jacobs; Emile S. Gardiner; K. Francis Salifu; Ronald P. Overton; George Hernandez; M. Elizabeth Corbin; Kevyn E. Wightman; Marcus F. Selig

145

Positive, Negative and Net Effects of Shrub-Tree Seedling Interactions in Red Pine Ecosystems  

Microsoft Academic Search

In forested ecosystems, young tree seedlings interact with already established vegetation such as adult trees, shrubs, herbs, understory trees, and other juvenile trees. The extent and nature of these interactions can affect growth rates of tree seedlings and their probability of survival. Thick shrub understories are thought to deter regeneration through increased mortality and slow growth of tree seedlings and

R. Montromery; P. B. Reich; S. B. Boyden; B. J. Palik

2009-01-01

146

[Physiological responses of mycorrhizal Pinus massoniana seedlings to drought stress and drought resistance evaluation].  

PubMed

A greenhouse pot experiment was conducted to study the effects of inoculating Pisolithus tinctorius, Cenococcum geophilum, Cantharellus cibarius, and Suillus luteus on the physiological characteristics of Pinus massoniana seedlings under the conditions of drought stress and re-watering, with the drought resistance of the mycorrhizal seedlings evaluated. Under drought stress, the MDA content and membrane' s relative permeability of P. massoniana seedlings increased, but these two indices in the inoculated (mycorrhizal) seedlings were significantly lower than these in the un-inoculated (control) seedlings. After re-watering, the MDA content and membrane's relative permeability of mycorrhizal seedlings had a rapid decrease, as compared with the control. In the first 21 days of drought stress, the production rate of superoxide radical of the seedlings increased, and the SOD, POD and NR activities of mycorrhizal seedlings increased significantly. With the extending of drought stress, the seedlings after re-watering had different recovery ability. Under the re-watering after 14 days drought stress, the SOD, POD and NR activities recovered. The drought resistance of the mycorrhizal seedlings was in the order of Suillus luteus 1 > Suillus luteus 7 > Cantharellus cibarius > Cenococcum geophilum > Pisolithus tinctorius. The SOD and MDA activities had a greater correlation with the mycorrhizal seedlings drought resistance, being able to be used as the indicators to evaluate the drought resistance of mycorrhizal seedlings. PMID:23755475

Wang, Yi; Ding, Gui-jie

2013-03-01

147

Terpenoid diversity in the leaf essential oils of Himalayan Lauraceae species.  

PubMed

The leaf terpenoid compositions of nine Lauraceae species, viz., Neolitsea pallens, Lindera pulcherrima, Dodecadenia grandiflora, Persea duthiei, Persea odoratissima, Persea gamblei, Phoebe lanceolata, Cinnamomum tamala, and Cinnamomum camphora, collected from the Himalayan region (India) were examined by GC, GC/MS, and NMR analyses in order to determine the similarities and differences among their volatile constituents. Furano-sesquiterpenoids were the principal constituents of N. pallens, L. pulcherrima, and D. grandiflora. (E)-Nerolidol, limonene, beta-pinene, and alpha-pinene were the major constituents of P. duthiei; alpha-pinene, sabinene, and beta-caryophyllene were predominant in P. odoratissima, while the oils of P. gamblei and P. lanceolata possessed beta-caryophyllene as common major constituent. C. camphora and C. tamala were marked by the presence of camphor and cinnamaldehyde, respectively. Cluster analysis of the oil composition was carried out in order to discern the differences and similarities within nine species of six genera of Lauraceae. PMID:19774599

Joshi, Subhash C; Padalia, Rajendra C; Bisht, Dinesh S; Mathela, Chandra S

2009-09-01

148

Effects of flooding on Eucalyptus camaldulensis and Eucalyptus globulus seedlings  

Microsoft Academic Search

Flooding for up to 40 days induced morphological changes and reduced growth of 6-week-old Eucalyptus camaldulensis and Eucalyptus globulus seedlings. However, the specific responses to flooding varied markedly between these species and with duration of flooding. Both species produced abundant adventitious roots that originated near the tap root and original lateral roots, but only E. camaldulensis produced adventitious roots on

A. R. Sena Gomes; T. T. Kozlowski

1980-01-01

149

Insulin Accelerates Seedling Growth of Canavalia ensiformis (Jack bean)  

Microsoft Academic Search

Insulin is a 6 kDa peptide hormone that activates several metabolic processes and cellular growth. Germination studies showed that insulin, vanadyl sulphate (an insulin mimetic compound), tyrphostin (an inhibitor of insulin receptor kinase activity), pinitol (a chiro inositol analogue) and glucose were able to accelerate Canavalia ensiformis (Jack bean) seedling radicle and epicotyl development. Immunofluorescence microscopy analysis showed that proteins

Antônia E. A. Oliveira; Elane S. Ribeiro; Maura da Cunha; Valdirene M. Gomes; Kátia V. S. Fernandes; José Xavier-Filho

2004-01-01

150

Using Electrolyte Leakage for Evaluating Hardwood Seedling Cold Hardiness  

Microsoft Academic Search

This paper describes the use of electrolyte leakage (EL) from stem tissue as a potential method for assessing cold hardiness of hardwood seedlings. The EL method has seen little use with North American hardwoods, but has successfully predicted conifer hardiness in both controlled and operational settings and has been used experimentally on hardwoods in Europe. Three species of hardwoods—northern red

Barrett C. Wilson; Douglass F. Jacobs

151

Utilization of Amygdalin during Seedling Development of Prunus serotina  

Microsoft Academic Search

Cotyledons of mature black cherry (Prunus serotina Ehrh.) seeds contain the cyanogenic diglucoside @)-amygdalin. The levels of amygdalin, its corresponding monoglucoside (R)-prunasin, and the enzymes that metabolize these cyanoglycosides were measured during the course of seedling development. During the first 3 weeks following imbibition, cotyledonary amygdalin levels declined by more than 80%, but free hydrogen cyanide was not released to

Elisabeth Swain; Jonathan E. Poulton

152

Protein phosphorylation differs significantly among ontogenetic phases in Malus seedlings  

PubMed Central

Background Although protein phosphorylation is an important post-translational modification affecting protein function and metabolism, dynamic changes in this process during ontogenesis remain unexplored in woody angiosperms. Methods Phosphorylated proteins from leaves of three apple seedlings at juvenile, adult vegetative and reproductive stages were extracted and subjected to alkaline phosphatase pre-treatment. After separating the proteins by two-dimensional gel electrophoresis and phosphoprotein-specific Pro-Q Diamond staining, differentially expressed phosphoproteins were identified by MALDI-TOF-TOF mass spectrometry. Results A total of 107 phosphorylated protein spots on nine gels (three ontogenetic phases?×?three seedlings) were identified by MALDI-TOF-TOF mass spectrometry. The 55 spots of ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) large-chain fragments varied significantly in protein abundance and degree of phosphorylation among ontogenetic phases. Abundances of the 27 spots corresponding to Rubisco activase declined between juvenile and reproductive phases. More extensively, phosphorylated ?-tubulin chain spots with lower isoelectric points were most abundant during juvenile and adult vegetative phases. Conclusions Protein phosphorylation varied significantly during vegetative phase change and floral transition in apple seedlings. Most of the observed changes were consistent among seedlings and between hybrid populations.

2014-01-01

153

Burst of ethylene upon horizontal placement of tomato seedlings  

NASA Technical Reports Server (NTRS)

Seedlings of Lycopersicon esculentum Mill. cv Rutgers emit a pulse of ethylene during the first 2 to 4 minutes following horizontal placement. Because this burst appears too rapid and brief to be mediated by increase in net activity of 1-aminocyclopropane-1-carboxylic acid synthase, it might result form accelerated transformation of vacuolar 1-aminocyclopropane-1-carboxylic acid to ethylene.

Harrison, M.; Pickard, B. G.

1984-01-01

154

Graviperception of Lentil Seedling Roots Grown in Space.  

National Technical Information Service (NTIS)

Lentil seedlings in Spacelab Biorack were used to examine in microgravity the distal complex of the endoplasmic reticulum and of the amyloplasts in order to: analyze the role of this contact on the growth and orientation of the root; determine, using the ...

G. Perbal D. Driss-Ecole G. Salle

1988-01-01

155

Heritability of some characteristics of Sorbus torminalis seedling.  

PubMed

This research was conducted to determine the heritability of some characteristics of wild service (Sorbus torminalis L. Crantz) seedling by a half-sib progeny test in north of Iran. The seeds of Sangdeh provenance (1600-1800 m a.s.l.) were collected from twenty individual parent trees and planted in a mountainous nursery (Orimelk, 1550 m a.s.l) as randomized complete block design with three replications. At the end of third growing season heritability of some seedling characteristics was determined with using Falconer method. Analyses indicated that heritability of biggest branch (h2 = 0.003) and branch number (h2 = 0.007) was lower than those of other characteristics measured. Heritability of collar diameter, vitality and total height was h2 = 0.22, h2 = 0.20 and h2 = 0.17, respectively. Among 20 parent trees the genotypes 2, 11, 18, 19 and 20 can be introduced as plus trees for seed providing and seedling production. It can be deduced that for seedling production of Sorbus torminalis in this nursery the parent trees should be benefited from a better collar diameter, vitality and total height in order to occurrence possibility of high-quality progenies. PMID:19070099

Tabandeh, Afagh; Tabari, Masoud; Nadoushan, Hossein Mirzaei; Espahbodi, Kambiz

2007-08-15

156

Nitrogen effects on seed germination and seedling growth  

Microsoft Academic Search

Recent evidence associates the persistence of invasive plant species with disturbance and fluctuations in distinct forms of mineral N in soils. We conducted soil and hydroponic experi- ments to investigate the influence of N form and availability on germination and seedling development of 2 invasive annual grasses, cheatgrass (Bromus tectorum) and medusahead (Taeniatherum caput-medusae) and 6 perennial grasses, blue- bunch

THOMAS A. MONACO; CHARLES T. MACKOWN; DOUGLAS A. JOHNSON; THOMAS A. JONES; JEANETTE M. NORTON; JAY B. NORTON; MARGARET G. REDINBAUGH

2003-01-01

157

Frost heaving of forest tree seedlings: a review  

Microsoft Academic Search

Soil frost heaving is the result of the formation of ice lenses in the soil caused by a segregation of the soil water. Ice lenses are growing from below and pushed upward. Seedlings heave when they are pushed out of the ground by the ice sheet formed at the surface of the soil. Frost heaving may greatly reduce growth and

France Goulet

1995-01-01

158

Anticandidial activity of some essential oils of a mega biodiversity hotspot in India.  

PubMed

Six essential oils viz. Eucalyptus citriodora, Cymbopogon citratus, Callistemon lanceolatus, Cinnamomum camphora, Citrus limon, Tagetes petula, as well as two standard antibiotics, miconazole and clotrimazole, were tested in vitro for their anticandidial activity. All these essential oils exhibited higher activity than the two synthetic antibiotics. Highest zone of inhibition was recorded in E. citriodora (8.50 mm microl-1) followed by C. lanceolatus (5.63 mm microl-1) establishing their promising anticandidial potential. PMID:17305775

Dutta, B K; Karmakar, S; Naglot, A; Aich, J C; Begam, M

2007-03-01

159

Ontogenetic photosynthetic changes, dispersal and survival of Thalassia testudinum (turtle grass) seedlings in a sub-tropical lagoon  

Microsoft Academic Search

Northward expansion of Thalassia testudinum (turtle grass) in Laguna Madre is occurring faster than can be explained by rhizome growth. We hypothesized that seedling establishment can account for the measured rates of meadow expansion and that seedling carbohydrate reserves are utilized until the plant is photosynthetically self-sufficient. To address seedling establishment, we estimated seed output, seedling dispersal and survival. Carbon

James E Kaldy; Kenneth H Dunton

1999-01-01

160

Effects of vesicular-arbuscular mycorrhizal (VAM) fungi on the seedling growth of three Pistacia species.  

PubMed

The experiment was undertaken to test the efficiency of inoculation of vesicular-arbuscular mycorrhizal (VAM) fungi on the seedling growth of three Pistacia species used as rootstocks. The stratified Pistacia seeds were inoculated with VAM fungi. The highest rate of inoculated roots was 96.7% in P. khinjuck seedlings with G. clarum and G. etunicatum, 83.3% in P. vera seedlings with G. caledonium and 73.3% in P. terebinthus seedlings with G. caledonium. Mycorrhizal inoculations improved seedling height only in P. terebinthus. Certain mycorrhizal inoculations increased the leaf N, but not P and K contents. Seedlings inoculated with G. caledonium had higher reducing sugar contents. It was concluded that pre-inoculated Pistacia seedlings could have a better growth in the harsh field conditions. PMID:17402238

Caglar, S; Akgun, A

2006-07-01

161

A mutation in Arabidopsis seedling plastid development1 affects plastid differentiation in embryo-derived tissues during seedling growth.  

PubMed

Oilseed plants like Arabidopsis (Arabidopsis thaliana) develop green photosynthetically active embryos. Upon seed maturation, the embryonic chloroplasts degenerate into a highly reduced plastid type called the eoplast. Upon germination, eoplasts redifferentiate into chloroplasts and other plastid types. Here, we describe seedling plastid development1 (spd1), an Arabidopsis seedling albino mutant capable of producing normal green vegetative tissues. Mutant seedlings also display defects in etioplast and amyloplast development. Precocious germination of spd1 embryos showed that the albino seedling phenotype of spd1 was dependent on the passage of developing embryos through the degreening and dehydration stages of seed maturation, suggesting that SPD1 is critical during eoplast development or early stages of eoplast redifferentiation. The SPD1 gene was found to encode a protein containing a putative chloroplast-targeting sequence in its amino terminus and also domains common to P-loop ATPases. Chloroplast localization of the SPD1 protein was confirmed by targeting assays in vivo and in vitro. Although the exact function of SPD1 remains to be defined, our findings reveal aspects of plastid development unique to embryo-derived cells. PMID:21045120

Ruppel, Nicholas J; Logsdon, Charles A; Whippo, Craig W; Inoue, Kentaro; Hangarter, Roger P

2011-01-01

162

Why Seedlings Die: Linking Carbon and Water Limitations to Mechanisms of Mortality During Establishment in Conifer Seedlings  

NASA Astrophysics Data System (ADS)

BACKGROUND Recent ecophysiological studies aimed at explaining adult tree mortality during drought have examined the carbon (C)-exhaustion compared to the hydraulic-failure hypotheses for death. Prolonged drought leads to durations of stomatal closure (and thus limited C gain), which could result in long periods of negative C balance and fatal reductions in whole-plant C reserves (i.e., available non-structural carbohydrates ["NSC"]). Alternatively, C reserves may not decrease much but could become increasingly inaccessible to sink tissues in long dry-periods due to impediments to translocation of photosynthate (e.g., through disruption of hydrostatic pressure flow in phloem). As C reserves decline or become inaccessible, continued maintenance respiration has been hypothesized to lead to exhaustion of NSC after extended durations of drought, especially in isohydric plant species. On the other hand, hydraulic failure (e.g., catastrophic xylem embolisms) during drought may be the proximate cause of death, occurring before true C starvation occurs. Few studies have investigated specifically the mechanism(s) of tree death, and no published studies that we know of have quantified changes in NSC during mortality. EXPERIMENTAL DESIGN AND HYPOTHESES We conducted two studies that investigated whole-tree and tissue-specific C relations (photosynthetic C gain, respiration, dry-mass gain, and NSC pools) in Pinus flexilis seedlings during the initial establishment phase, which is characterized by progressive drought during summer. We measured survival, growth and biomass allocation, and C-balance physiology (photosynthetic C-gain and chlorophyll fluorescence, respiration C-use, and NSC concentrations) from germination to mortality. We hypothesized that 1) stomatal and biochemical limitations to C gain would constrain seedling survival (through inadequate seasonal C-balance), as has been shown for conifer seedlings near alpine treeline; 2) hydraulic constraints (embolisms and/or reduced hydraulic conductance), associated with roots unable to escape the seasonal drying front in the soil, would limit seedling survival at least as much as C-balance dysfunction; and 3) seedling mortality would not be due to exhaustion of whole-plant NSC, as suggested by appreciable NSC in dead conifer seedlings reported in alpine treeline studies. RESULTS AND INTERPRETATIONS Preliminary results suggest that photosynthesis, fluorescence, and whole-tree NSC remained high until mortality, when plant water potentials decreased below -5 MPa. As seedlings approached mortality, NSC concentrations (both soluble sugars and starch) in roots decreased from ~9% to <3% of dry-mass. In aboveground tissues, NSC concentrations also declined initially (from ~12% to 3% of dry-mass), but then increased in needles (up to 8% dry-mass) and especially stems (up to 16% dry-mass), suggesting impediments to phloem-translocation in stems. Thus, seedling death could not be directly attributed to dysfunction of C-balance physiology, or exhaustion of NSC at the whole-plant level. We propose that hydraulic failure was likely the proximate cause of mortality under the conditions we evaluated, and drought-induced inhibition of NSC transport to roots may ultimately undermine the ability of seedlings to tap progressively deeper water sources during summer drying.

Reinhardt, K.; Germino, M. J.; Kueppers, L. M.; Mitton, J.; Castanha, C.

2012-12-01

163

Implications of seed size for seedling survival in Carnegiea gigantea and Ferocactus wislizeni (Cactaceae)  

USGS Publications Warehouse

Larger seeds have been shown to convey benefits for seedling survival but the mechanisms of this process are not well understood. In this study, seed size and seedling survival were compared for 2 sympatric cactus species, Carnegiea gigantea (Engelm.) Britt. & Rose and Ferocactus wislizeni (Engelm.) Britt. & Rose, in laboratory and field experiments in the northern Sonoran Desert. Both species have small seeds, but Ferocactus seeds are nearly twice as long and 3 times as heavy as those of Carnegiea. The difference in size is perpetuated after germination: new Ferocactus seedlings have 4 times the estimated volume of new Carnegiea seedlings. In an outdoor experiment, annual survivorship of both species was low but was 6 times higher for Ferocactus (6 seedlings, 8.1%) than Carnegiea (1 seedling, 1.4%). The pattern of seedling mortality in relation to temperature and rain suggests that, after the initial flush of seed and seedling predation, drought and heat took a greater toll on Carnegiea than Ferocactus seedlings, probably because the larger seedling volume of Ferocactus conferred greater drought tolerance. In addition, F. wislizeni could become established without benefit of nurse plants whereas C. gigantea could not; this might reflect differential tolerance to high soil temperatures.

Bowers, J. E.; Pierson, E. A.

2001-01-01

164

Lipid utilization, gluconeogenesis, and seedling growth in Arabidopsis mutants lacking the glyoxylate cycle enzyme malate synthase.  

PubMed

The aim of this research was to test the role of the glyoxylate cycle enzyme malate synthase (MLS) in lipid utilization, gluconeogenesis, and seedling growth in Arabidopsis. We hypothesized that in the absence of MLS, succinate produced by isocitrate lyase (ICL) could still feed into the tricarboxylic acid cycle, whereas glyoxylate could be converted to sugars using enzymes of the photorespiratory pathway. To test this hypothesis we isolated knock-out mls mutants and studied their growth and metabolism in comparison to wild type and icl mutant seedlings. In contrast to icl seedlings, which grow slowly and are unable to convert lipid into sugars (Eastmond, P. J., Germain, V., Lange, P. R., Bryce, J. H., Smith, S. M. & Graham, I. A. (2000) Proc. Natl. Acad. Sci. U. S. A. 97, 5669-5674), mls seedlings grow faster, use their lipid more rapidly, and are better able to establish as plantlets. Transcriptome and metabolome analyses show that icl seedlings exhibit many features characteristic of carbohydrate starvation, whereas mls seedlings differ relatively little from wild type. In the light mls seedlings generate more sugars than icl seedlings, and when fed with [14C]acetate, 14C-labeling of sugars is three times greater than in icl seedlings and more than half that in wild type seedlings. The mls seedlings also accumulate more glycine and serine than icl or wild type seedlings, consistent with a diversion of glyoxylate into these intermediates of the photorespiratory pathway. We conclude that, in contrast to bacteria and fungi in which MLS is essential for gluconeogenesis from acetate or fatty acids, MLS is partially dispensable for lipid utilization and gluconeogenesis in Arabidopsis seedlings. PMID:15272001

Cornah, Johanna E; Germain, Véronique; Ward, Jane L; Beale, Michael H; Smith, Steven M

2004-10-01

165

Growth distribution during phototropism of Arabidopsis thaliana seedlings  

SciTech Connect

The elongation rates of two opposite sides of hypocotyls of Arabidopsis thaliana seedlings were measured during phototropism by using an infrared imaging system. In first positive phototropism, second positive phototropism, and red light-enhanced first positive phototropism, curvature toward the light source was the result of an increase in the rate of elongation of the shaded side and a decrease in the rate of elongation of the lighted side of the seedlings. The phase of straightening that followed maximum curvature resulted from a decrease in the elongation rate of the shaded side and an increase in the elongation rate of the lighted side. These data for the three types of blue light-induced phototropism tested in this study and for the phase of straightening are all clearly consistent with the growth rate changes predicted by the Cholodny-Went theory. 31 refs., 7 figs.

Orbovic, V.; Poff, K.L. (Michigan State Univ., East Lansing, MI (United States))

1993-09-01

166

A Technique for Collection of Exudate from Pea Seedlings 1  

PubMed Central

Ethylenediaminetetraacetic acid (EDTA), at concentrations higher than 1.0 millimolar, is phytotoxic to etiolated seedlings of Pisum sativum. Substantial vascular exudation from pea epicotyls could be obtained without tissue damage at 0.5 millimolar EDTA if the solution was buffered at pH 7.5 with sodium N-2-hydroxyethylpiperazine-N?-2-ethanesulfonic acid. Treated seedlings exuded 950 micrograms (leucine equivalents) of ninhydrin-positive material per day and 870 micrograms (glucose equivalents) of anthrone-positive material per day. Amino acid analysis showed the exudate to have glutamine as the major amido nitrogen containing compound and sucrose was shown to be the major sugar. Radiolabeled tryptophan and sucrose applied to cotyledons were transferred through the epicotyl and into the collection medium. The pH profile for exudation shows half maximal exudation at pH 7.2, indicating the promotion of exudation by EDTA is probably not due simply to Ca2+ chelation.

Hanson, Susan D.; Cohen, Jerry D.

1985-01-01

167

Seedling response to sulfur, nitrogen, and associated pollutants  

SciTech Connect

In 1986, the National Acid Precipitation Assessment Program (NAPAP) established the Forest Response Program (FRP) to assess the effects of acidic deposition and associated pollutants on forests. Seedling exposure studies were initiated to determine acute effects of simulated acid deposition, ozone, and sulfur dioxide, and to identify hypothesized mechanisms be which these effects might alter tree condition and hence result in forest decline. From data available as of December 1988, altered post-exposure growth and imbalance in above- and below-ground responses to sulfur dioxide indicated changes in carbon allocation patterns. Simulated acid precipitation reduced frost hardiness of red spruce seedlings at pH 3.0 and led to higher rates of foliar tissue mortality during extreme cold. Loblolly pine showed root and stem growth decreases at ozone levels 80 ppb and higher. Of western conifers, only ponderosa pine showed consistent growth decreases due to ozone.

Peterson, C.E.; Mattson, K.G.; Mickler, R.A.

1989-11-01

168

A technique for collection of exudate from pea seedlings  

NASA Technical Reports Server (NTRS)

Ethylenediaminetetraacetic acid (EDTA), at concentrations higher than 1.0 millimolar, is phytotoxic to etiolated seedlings of Pisum sativum. Substantial vascular exudation from pea epicotyls could be obtained without tissue damage at 0.5 millimolar EDTA if the solution was buffered at pH 7.5 with sodium N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid. Treated seedlings exuded 950 micrograms (leucine equivalents) of ninhydrin-positive material per day and 870 micrograms (glucose equivalents) of anthrone-positive material per day. Amino acid analysis showed the exudate to have glutamine as the major amido nitrogen containing compound and sucrose was shown to be the major sugar. Radiolabeled tryptophan and sucrose applied to cotyledons were transferred through the epicotyl and into the collection medium. The pH profile for exudation shows half maximal exudation at pH 7.2, indicating the promotion of exudation by EDTA is probably not due simply to Ca2+ chelation.

Hanson, S. D.; Cohen, J. D.; Bandurski, R. S. (Principal Investigator)

1985-01-01

169

Evaluation of Citrus Rootstocks for Salinity Tolerance at Seedling Stage  

Microsoft Academic Search

Citrus rootstocks i.e. Jatti khatti (Citrus jambhiri), Jambheri khatti (C. jambhiri), Gada dehi (C. aurantium), Kharna khatta (C. karna), Cleopatra mandarin (C. reshni) and Yuma citrange (Poncirus trifoliata x C. sinensis) were evaluated for salinity tolerance by transplanting their six months old seedlings in an artificially salinized soil. Four salinity levels i.e. 2.0, 4.0, 6.0 and 8.0 dS m-1, were

MUHAMMAD AKBAR ANJUM; MUHAMMAD ABID; FARRUKH NAVEED

170

Enantioselective separation and phytotoxicity on rice seedlings of paclobutrazol.  

PubMed

The environmental significance of enantioselectivity in chiral insecticides and herbicides has been widely studied. However, little information is currently available on the enantioselective behavior of chiral plant growth regulators. In this study, paclobutrazol enantiomers were resolved and prepared by chiral high-performance liquid chromatography with a Sino-chiral OJ column. The relationship among absolute configuration, optical activity and circular dichroism of paclobutrazol enantiomers was established. The enantioselective behavior of paclobutrazol, including enantioselective effect of paclobutrazol on the growth of rice seedlings and cyanobacteria and enantioselective loss of paclobutrazol in rice seedling growth media, in rice culture system was studied. The (2S,3S)-(-)-enantiomer was almost 3.1 times more active than the (2R,3R)-(+)-enantiomer toward shoot growth as measured by 7 day EC50 values. Enantioselectivity could not be determined with respect to root growth of rice seedlings because a typical dosage response was not observed in the range of the concentrations studied. The dissipation of paclobutrazol in rice growth medium is not enantioselective. Enantiomers and diastereoisomer of paclobutrazol all facilitated the growth of cyanobacteria, which increase the effectiveness of rice biofertilizers. The (2S,3S)-(-)-enantiomer showed stronger stimulatory activity on Microcystis aeruginosa cyanobacteria than the (2R,3R)-(+)-enantiomer, whereas the latter was a more potent stimulator of Anabaena sp. growth. These observations indicate that application of the (2S,3S)-(-)-enantiomer of paclobutrazol and Microcystis aeruginosa in rice cultivation is a good strategy for improving rice seedling performance. PMID:21395310

Zhang, Anping; Xie, Xuemei; Liu, Weiping

2011-04-27

171

Tree Seedling Production Systems in Northern Mindanao, Philippines  

Microsoft Academic Search

This paper examines seedling production systems for small-scale forestry in northern Mindanao, particularly the constraints\\u000a and opportunities to sustain the operation of smallholder nurseries. Various types of nurseries were identified to examine\\u000a issues and concerns operators face, and data collected through a survey of nursery operators, discussion with government and\\u000a NGO personnel, and literature review. Many smallholders in northern Mindanao

Agustin R. Mercado Jr; Caroline Duque-Pińon

2008-01-01

172

Amelioration of chilling stress by triadimefon in cucumber seedlings  

Microsoft Academic Search

Cucumber (Cucumis satvus L.) seeds were imbibed in distilled water (control) and 10 mg l-1 triadimefon (TDM) for 10 h and then grown in a plant growth chamber with a light\\/dark temperature of 28\\/20 °C and a photoperiod of 14 h with a light intensity of 60 µmol m-2 s-1. 14-day-old seedlings were exposed to chilling stress with a light\\/dark

Zhaozhong Feng; Anhong Guo; Zongwei Feng

2003-01-01

173

Antioxidant responses of rice seedling to Ce?+ under hydroponic cultures.  

PubMed

Since the 1980s, rare earth elements have been commonly used in China because of their enriched fertilizers. To understand the potential benefits or damages of Ce(4+) on rice, the antioxidant responses (superoxide dismutase, ascorbate peroxidase, catalase activities, and ascorbate and glutathione contents) of rice seedling to Ce(4+) under hydroponic cultures were investigated. The results showed that Ce(4+) induced H(2)O(2) and O(2)(-) production of rice seedling. The inhibition studies with diphenylene iodonium suggested that the key enzyme responsible for oxidative bursts was primarily NADPH oxidase. Ce(4+) (0.02 mM) increased the antioxidant capacity of reduced ascorbate and glutathione and the levels of superoxide dismutase, ascorbate peroxidase, and catalase. However, antioxidant enzymes and antioxidant capacity of rice seedling were decreased by 0.2mM Ce(4+) treatment, indicating that higher content of Ce(4+) damaged the mechanism of defense responses and emerged the peroxidation of membrane lipids. These results will help us to understand the mechanism of Ce(4+) on rice and concern about its environmental impact in agriculture. PMID:21514673

Xu, Qiu-Man; Chen, Hong

2011-09-01

174

Rhythmical changes in the sensitivity of cotton seedlings to herbicides.  

PubMed

Cotton (Gossypium hirsutum L.) seedlings that were grown under a photoperiod of 12 hours darkness and 12 hours light showed oscillations in their sensitivity to the herbicides sodium 5-(2-chloro-4-trifluoromethyl)-phenoxy)-2-nitrobenzoate (acifluorfen), butyl 2-(4-((5-(trifluoromethyl)-2-pyridinyl)oxy)phenoxy)propanoate (fluazifop) and 3-isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide (bentazon). Sensitivity was expressed in appearance of necrotic areas on the cotyledons and in decreased growth of the shoot. The seedlings were least sensitive in the beginning and middle of the light period, then the sensitivity increased and reached its maximum during the beginning and middle of the dark period and then declined. Seedlings grown from germination under continuous light exhibited very small or no oscillations in sensitivity. The oscillations in sensitivity were entrained by one cycle of darkness and light. A cycle of 12 hours darkness and 12 hours light triggered the greatest oscillations while either increasing or decreasing the duration of the dark period resulted in smaller oscillations. Apparently, these oscillations in sensitivity to herbicides were endogenously controlled since after entrainment they continued irrespective of the light conditions. PMID:16663835

Rikin, A; John, J B; Wergin, W P; Anderson, J D

1984-10-01

175

Turnover of dhurrin in green sorghum seedlings. [Sorghum bicolor  

SciTech Connect

The turnover of dhurrin in green seedlings of Sorghum bicolor (Linn) Moench var Redland x Greenleaf, Sudan 70 has been investigated using glyphosate and pulse-labeling studies with {sup 14}C-tyrosine and ({sup 14}C)shikimic acid. The rate of dhurrin breakdown was 4.8 nanomoles per hour in the shoot and 1.4 nanomoles per hour in the root. The rate of dhurrin accumulation in the shoot of 4- to 5-day-old seedlings was high but decreased with age until at the peak period of dhurrin accumulation, the rates of dhurrin synthesis and breakdown were equal. Using a first order equation (an approximation) the rate of dhurrin synthesis (which equals accumulation plus breakdown rates) was 17.4 nanomoles per hour in the shoot and 4.1 nanomoles per hour in the root. In both tissues, the breakdown rate was between 27 and 34% of their synthetic capacity within the experimental period. Dhurrin synthesis in green sorghum seedlings occurred in both the light and dark photoperiods but was faster in the dark period. The result is discussed in relation to the possible metabolic roles of the turnover.

Adewusi, S.R.A. (Obafemi Awolowo Univ., Ile-Ife (Nigeria))

1990-11-01

176

Endophytic fungi reduce leaf-cutting ant damage to seedlings.  

PubMed

Our study examines how the mutualism between Atta colombica leaf-cutting ants and their cultivated fungus is influenced by the presence of diverse foliar endophytic fungi (endophytes) at high densities in tropical leaf tissues. We conducted laboratory choice trials in which ant colonies chose between Cordia alliodora seedlings with high (E(high)) or low (E(low)) densities of endophytes. The E(high) seedlings contained 5.5 times higher endophyte content and a greater diversity of fungal morphospecies than the E(low) treatment, and endophyte content was not correlated with leaf toughness or thickness. Leaf-cutting ants cut over 2.5 times the leaf area from E(low) relative to E(high) seedlings and had a tendency to recruit more ants to E(low) plants. Our findings suggest that leaf-cutting ants may incur costs from cutting and processing leaves with high endophyte loads, which could impact Neotropical forests by causing variable damage rates within plant communities. PMID:20610420

Bittleston, L S; Brockmann, F; Wcislo, W; Van Bael, S A

2011-02-23

177

Machine vision system for quality control assessment of bareroot pine seedlings  

NASA Astrophysics Data System (ADS)

A PC-based machine vision system was used at a forest nursery for two months to make quality control measurements of bareroot pine seedlings. In tests conducted during the lifting season, there was close agreement between machine vision and manual measurement distribution results for seedling samples for both root collar diameter and tap root length. During a second set of tests conducted after adding a bud tip height measurement routine, measurement distribution results for seedling samples were in close agreement for root collar diameter, tap root length, and bud tip height. Machine vision measurements of root collar diameter and tap root length also correlated well with manual measurements on a seedling-to- seedling basis for the second test. With the machine vision system, seedling samples could be measured by one person in approximately the same amount of time that it took two people to measure them manually.

Wilhoit, John H.; Kutz, L. J.; Vandiver, W. A.

1995-01-01

178

The Effects of Seed Mass on Germination, Seedling Emergence, and Early Seedling Growth of Eastern White Pine ( Pinus strobus L.)  

Microsoft Academic Search

Half-sib seed of several eastern white pine (Pinus strobus L.) families was used to examine seed mass effects on laboratory germination, and seedling emergence and growth under moderate\\u000a and low light (47 and 13% full sunlight) in a greenhouse. Percent germination and speed of germination under laboratory conditions\\u000a were not related to seed mass among half-sib families or multi-family seedlots

William C. Parker; Thomas L. Noland; Andrée E. Morneault

2006-01-01

179

Early root growth plasticity in seedlings of three Mediterranean woody species  

Microsoft Academic Search

Since very young seedlings are sensitive to dehydration, soil desiccation is often responsible for seedling death in water-stressed\\u000a environments. Roots play a major role in overcoming water stress and plant establishment, thus early root development in response\\u000a to limited water availability becomes a strategy that may ensure seedling recruitment. We explored whether different water\\u000a availabilities altered growth patterns of very

Francisco M. Padilla; Juan de Dios Miranda; Francisco I. Pugnaire

2007-01-01

180

Functional performance of oak seedlings naturally regenerated across microhabitats of distinct overstorey canopy closure  

Microsoft Academic Search

The extent to which seedling recruitment is limited by summer drought in Mediterranean-type ecosystems depends on the light\\u000a microsite, yet the relationship between light availability and water status, functional performance, and survival of seedlings\\u000a in these systems is still unclear. Over a 3-year period, we studied the pattern of survival and functional performance of\\u000a seedlings of Quercus petraea (Matt.) Liebl.

J. Rodríguez-Calcerrada; F. J. Cano; M. Valbuena-Carabańa; L. Gil; I. Aranda

2010-01-01

181

Evaluation of Fumigants, EPTC Herbicide, and Paenibacillus macerans in the Production of Loblolly Pine Seedlings  

Microsoft Academic Search

Chloropicrin fumigation, Eptam 7-E (EPTC) herbicide, and Paenibacillus macerans seed treatments were evaluated as alternatives to fumigation with methyl bromide\\/chloropicrin for loblolly pine (Pinus taeda L.) seedling production at three nurseries in the southern United States. A treatment of metam sodium\\/chloropicrin was also evaluated at one nursery. Seedling density was unaffected by fumigation and EPTC treatments at all nurseries. Seedling

Michelle M. Cram; Scott A. Enebak; Stephen W. Fraedrich; Lew D. Dwinell; Stanley J. Zarnoch

2007-01-01

182

Destruction of Chlorophyll in Emerging Seedlings of Spring Barley Associated with Environmental Stresses  

Microsoft Academic Search

K?DELA V., VOŽENÍLKOV Á B., KREJZAROV Á R., KREJZAR V., JANOUCH M. (2005): Destruction of chlorophyll in emerging seedlings of spring barley associated with environmental stresses. Plant Protect. Sci., 41: 165-170. An unusual disorder occurred on spring barley seedlings in southern and central Bohemia in April 2005. Af- fected seedlings showed conspicuous bleached or straw-coloured areas on tips of the

BOHUMILA VOŽENÍLKOV Á; RADKA KREJZAROV Á; VÁCLAV KREJZAR; MICHAL JANOUCH

2005-01-01

183

Germination and seedling survival of Argan ( Argania spinosa) under experimental saline conditions  

Microsoft Academic Search

Solutions of NaCl at various concentrations (0, 2·5, 5, 7·5 and 10 gl?1) were used to treat argan (Argania spinosa (L.) Skeels) at germination and as container-grown seedlings. We assessed germination percentage, radicle length and dry weight as well as seedling survival and number of days before seedling collapse. Increasing salt concentration did not delay the beginning of germination but

Fouzia Bani-Aameur; Janis Sipple-Michmerhuizen

2001-01-01

184

Influence of exogenic salicylic acid on Fusarium seedling blight reduction in barley  

Microsoft Academic Search

Salicylic acid (SA) applied at concentrations from 1–10 µg·ml?1 to germinating seeds of 8 barley cultivars reduced the disease rating of seedlings. Seedlings of barley not treated with\\u000a SA and inoculated with Fusarium culmorum exhibited disease rating of root on avarage 76 %. Seedlings treated before inoculation with solution of SA 1, 2, 5 and 10\\u000a µg\\/ml exhibited significantly lower

H. Wi?niewska; J. Che?kowski

1999-01-01

185

Piriformospora indica rescues growth diminution of rice seedlings during high salt stress  

PubMed Central

Piriformospora indica association has been reported to increase biotic as well as abiotic stress tolerance of its host plants. We analyzed the beneficial effect of P. indica association on rice seedlings during high salt stress conditions (200 and 300 mM NaCl). The growth parameters of rice seedlings such as root and shoot lengths or fresh and dry weights were found to be enhanced in P. indica-inoculated rice seedlings as compared with non-inoculated control seedlings, irrespective of whether they are exposed to salt stress or not. However, salt-stressed seedlings performed much better in the presence of the fungus compared with non-inoculated control seedlings. The photosynthetic pigment content [chlorophyll (Chl) a, Chl b, and carotenoids] was significantly higher in P. indica-inoculated rice seedlings under high salt stress conditions as compared with salt-treated non-inoculated rice seedlings, in which these pigments were found to be decreased. Proline accumulation was also observed during P. indica colonization, which may help the inoculated plants to become salt tolerant. Taken together, P. indica rescues growth diminution of rice seedlings under salt stress.

Jogawat, Abhimanyu; Saha, Shreya; Bakshi, Madhunita; Dayaman, Vikram; Kumar, Manoj; Dua, Meenakshi; Varma, Ajit; Oelmuller, Ralf; Tuteja, Narendra; Johri, Atul Kumar

2013-01-01

186

Ames Research Center views of Oats, Slash-Pine and Mung bean seedlings STS-3  

NASA Technical Reports Server (NTRS)

Young oat seedlings are shown in a ground laboratory after being flown into space aboard the Space Shuttle Columbia on STS-3 in March of 1982. All plants were part of the experimental Plant Growth Unit. They appear to have grown to look similar to the control seedlings on earth. A few small roots can be seen growing upward from the soil (33915); Young slash-pine seedlings are shown upon returning from the STS-3 mission (33916); Mung bean seedlings are shown after their return from space aboard the STS-3 (37917).

1982-01-01

187

Piriformospora indica rescues growth diminution of rice seedlings during high salt stress.  

PubMed

Piriformospora indica association has been reported to increase biotic as well as abiotic stress tolerance of its host plants. We analyzed the beneficial effect of P. indica association on rice seedlings during high salt stress conditions (200 and 300 mM NaCl). The growth parameters of rice seedlings such as root and shoot lengths or fresh and dry weights were found to be enhanced in P. indica-inoculated rice seedlings as compared with non-inoculated control seedlings, irrespective of whether they are exposed to salt stress or not. However, salt-stressed seedlings performed much better in the presence of the fungus compared with non-inoculated control seedlings. The photosynthetic pigment content [chlorophyll (Chl) a, Chl b, and carotenoids] was significantly higher in P. indica-inoculated rice seedlings under high salt stress conditions as compared with salt-treated non-inoculated rice seedlings, in which these pigments were found to be decreased. Proline accumulation was also observed during P. indica colonization, which may help the inoculated plants to become salt tolerant. Taken together, P. indica rescues growth diminution of rice seedlings under salt stress. PMID:24494239

Jogawat, Abhimanyu; Saha, Shreya; Bakshi, Madhunita; Dayaman, Vikram; Kumar, Manoj; Dua, Meenakshi; Varma, Ajit; Oelmüller, Ralf; Tuteja, Narendra; Johri, Atul Kumar

2013-10-01

188

Effects of Ectomycorrhizae Removal on Survival and Growth of Loblolly Pine Seedlings with Pisolithus or Natural Ectomycorrhizae on an Upland Site in South Carolina.  

National Technical Information Service (NTIS)

This study was undertaken to ascertain the significance of loss of ectomycorrhizae encountered during lifting of nursery seedlings to the capacity of the seedlings. Loblolly pine seedlings with abundant Pisolithus tinctorius (Pt) or naturally occurring (N...

D. H. Marx

1981-01-01

189

Analysis of peg formation in cucumber seedlings grown on clinostats and in a microgravity (space) environment  

NASA Technical Reports Server (NTRS)

In young cucumber seedlings, the peg is a polar out-growth of tissue that functions by snagging the seed coat, thereby freeing the cotyledons. Previous studies have indicated that peg formation is gravity dependent. In this study we analyzed peg formation in cucumber seedlings (Cucumis sativus L. cv Burpee Hybrid II) grown under conditions of normal gravity, microgravity, and simulated microgravity (clinostat rotation). Seeds were germinated on the ground, in clinostats and on board the space shuttle (STS 95) for 1-2 days, frozen and subsequently examined for their stage of development, degree of hook formation, number of pegs formed, and peg morphology. The frequency of peg formation in space grown seedlings was found to be nearly identical to that of clinostat grown seedlings and to differ from that of seedlings germinated under normal gravity only in a minority of cases; approximately 6% of the seedlings formed two pegs and nearly 2% of the seedlings lacked pegs, whereas such abnormalities did not occur in ground controls. The degree of hook formation was found to be less pronounced for space grown seedlings, compared to clinostat grown seedlings, indicating a greater degree of decoupling between peg formation and hook formation in space. Nonetheless, in all seedlings having single pegs and a hook, the peg was found to be positioned correctly on the inside of the hook, showing that there is coordinate development even in microgravity environments. Peg morphologies were altered in space grown samples, with the pegs having a blunt appearance and many pegs showing alterations in expansion, with the peg extending out over the edges of the seed coat and downwards. These phenotypes were not observed in clinostat or ground grown seedlings.

Link, B. M.; Cosgrove, D. J.

1999-01-01

190

Following isotopes in pulse-chase enriched aspen seedlings  

NASA Astrophysics Data System (ADS)

One method to quantitatively trace biogeochemical fluxes through ecosystems, such as organic matter decomposition, is to use plant material enriched with stable isotopes. However, as plant macromolecules are known to vary in their rate of formation and decomposition, both the enrichment levels and the location of enrichment within the plant material should be characterized prior to decomposition and tracing studies. Aspen (Populus tremuloides Michx.) is a common tree species with a diverse organic matter chemical structure found in the western Canadian boreal forest. This study used a multi pulse and multi chase enrichment of stable isotopes (15N and 13C) on aspen seedlings to determine the seedling enrichment, isotope movement among plant tissues and translocation of isotopes within plant macromolecules e.g., carbohydrates and lignin. As expected, all tissues experienced increased enrichment with multiple pulses. An initial enrichment with 13C was observed in the leaves followed by translocation to the stems and roots while the 15N moved upward from the roots to leaves. The macromolecular chemistry of the organic carbon was further characterized using 13C solid state nuclear magnetic resonance spectroscopy. After the initial two hour chase period enrichment of the O-alkyl type (carbohydrate) carbon within the leaves was identified, followed by redistribution to more complex carbon compounds after the one week chase period. Root and stem tissues did not show the same pattern. Rather, changes in 13C enrichment were observed in shifting ethyl and methyl alkyl (lipid) carbon peak intensities for the stem samples while roots did not preferentially allocate 13C to a specific macromolecule. These results confirm that stable isotope enrichment of plants was non-uniform across macromolecules and tissue types. Enrichment of aspen seedlings was therefore dependant on the pulse-chase sequence used.

Norris, C. E.; Wasylishen, R. E.; Landhäusser, S.; Quideau, S. A.

2011-12-01

191

Triterpene constituents from the seedling of Aronia melanocarpa  

Microsoft Academic Search

Two new triterpene saponins, 16-O-acetyl-21-O-angeloyltheasapogenol A 3-O-[?-d-galactopyranosyl(1 ? 2)][?-d-xylopyranosyl(1 ? 2)-?-l-arabinopyranosyl (1 ? 3)]-?-d-glucopyranosiduronic acid (1) and 16,28-O-diacetyl-21-O-tigloyltheasapogenol A 3-O-[?-d-galactopyranosyl(1 ? 2)][?-d-xylopyranosyl(1 ? 2)-?-l-arabinopyranosyl (1 ? 3)]-?-d-glucopyranosiduronic acid (2), together with four known triterpenenes, have been isolated from the dried seedling of Aronia melanocarpa, and their structures established by spectroscopic and chemical evidence.

M. Yu; X. Li; C.-C. Zhao; J. Xu; P. Zhang

2007-01-01

192

Anaerobic accumulation of 4-aminobutyrate in rice seedlings; Causes and significance  

Microsoft Academic Search

Accumulation of 4-aminobutyrate is induced by anoxia in rice seedlings. The induction of 4-aminobutyrate accumulation in aerobic conditions by treatments with exogenous 4-aminobutyrate, Gabaculine and glutamate is well tolerated by the seedlings. The inhibition of protein synthesis in aerobic and anaerobic conditions by cycloheximide shows that this process competes with glutamate decarboxylase for glutamic acid. The sensitivity of the anaerobic

Nicoletta Aurisano; Alcide Bertani; Remo Reggiani

1995-01-01

193

Root carbon reserve dynamics in aspen seedlings: does simulated drought induce reserve limitation?  

PubMed

In a greenhouse study we quantified the gradual change of gas exchange, water relations and root reserves of aspen (Populus tremuloides Michx.) seedlings growing over a 3-month period of severe water stress. The aim of the study was to quantify the complex interrelationship between growth, water and gas exchange, and root carbon (C) dynamics. Various growth, gas exchange and water relations variables in combination with root reserves were measured periodically on seedlings that had been exposed to a continuous drought treatment over a 12-week period and compared with well-watered seedlings. Although gas exchange and water relations parameters significantly decreased over the drought period in aspen seedlings, root reserves did not mirror this trend. During the course of the experiment roots of aspen seedlings growing under severe water stress showed a two orders of magnitude increase in sugar and starch content, and roots of these seedlings contained more starch relative to sugar than those in non-droughted seedlings. Drought resulted in a switch from growth to root reserves storage which indicates a close interrelationship between growth and physiological variables and the accumulation of root carbohydrate reserves. Although a severe 3-month drought period created physiological symptoms of C limitation, there was no indication of a depletion of root C reserve in aspen seedlings. PMID:21444372

Galvez, David A; Landhäusser, S M; Tyree, M T

2011-03-01

194

Growth response and nutrient utilization of Casuarina equisetifolia seedlings inoculated with bioinoculants under tropical nursery conditions  

Microsoft Academic Search

We investigated the role of tetrapartite associations between an arbuscular mycorrhizal (AM) fungus (Glomus geosporum), phosphate solubilizing bacteria (Paenibacillus polymyxa), Frankia and Casuarina equisetifolia on growth, nutrient acquisition, nutrient utilization and seedling quality of C. equisetifolia. Seedlings of C. equisetifolia were grown in an Alfisol soil and inoculated with G. geosporum, P. polymyxa and Frankia either individually or in combinations.

Thangavelu Muthukumar; Karuthamuthu Udaiyan

2010-01-01

195

Survival of tree seedlings across space and time: estimates from long-term count data  

Microsoft Academic Search

Summary 1 Tree diversity in forests may be maintained by variability in seedling recruitment. Although forest ecologists have emphasized the importance of canopy gaps in gener- ating spatial variability that might promote tree regeneration, the effects of canopy gaps on seedling recruitment may be offset by dense forest understories. 2 Large annual fluctuations in recruitment processes, coupled with the long

BRIAN BECKAGE; MICHAEL LAVINE; JAMES S. CLARK

2005-01-01

196

Performance of loblolly pine ( Pinus taeda L.) seedlings and micropropagated plantlets on an east Texas site  

Microsoft Academic Search

East Texas contains the western extent of the natural range of loblolly pine (Pinus taeda L.) and, therefore, many planted seedlings there experience water deficit sometimes leading to plantation failure. One solution may be to regenerate with clonally propagated drought-hardy planting stock. The objective of this research was to compare the field performance of loblolly pine seedlings and plantlets of

Mohd S Rahman; Michael G Messina; Ronald J Newton

2003-01-01

197

Seed germination and seedling growth of the Mexican sunflower Tithonia diversifolia (Compositae) in Nigeria, Africa  

Microsoft Academic Search

We studied seed germination and seedling growth of the Mexican sunflower Tithonia diversifolia in Nigeria. This involved the usage of some dormancy-releasing methods and the effect of some concentrations of three herbicide formulations on the young seedlings. Initial germination tests on fresh and stored seeds revealed a low percentage germination of less than 30%. The seeds of the weed exhibit

D. A. Agboola; W. F. Idowu; M. Kadiri

198

Effect of arbuscular mycorrhizal fungi on damping-off disease in Aquilaria agallocha Roxb. seedlings  

Microsoft Academic Search

Damping-off disease of Aquilaria agallocha seedlings caused by the pathogenic fungus (Pythium aphanidermatum) results in poor regeneration under natural conditions and in the nursery. In the present study, Glomus fasciculatum, an arbuscular mycorrhizal (AM) fungus was examined for its ability to reduce the rotting incidence of Aquilaria seedlings. Dual inoculations (AM+pathogen) restricted the progression of the pathogen in the root

T. TABIN; A. ARUNACHALAM; K. SHRIVASTAVA; K. ARUNACHALAM

199

Visual Detection of Transposition of the Maize Element Activator (Ac) in Tobacco Seedlings  

Microsoft Academic Search

A bacterial streptomycin resistance gene (SPT) was engineered to make it possible to detect visually the transposition of the maize transposon Activator (Ac) in tobacco. In the presence of streptomycin, transgenic seedlings carrying the SPT gene appear green, whereas those carrying an SPT::Ac construct display clones of green cells on a white background. Fully green seedlings arise in the progeny

Jonathan D. G. Jones; Francine M. Carland; Pal Maliga; Hugo K. Dooner

1989-01-01

200

Influence of soil mixing and sterilization on growth and nutrient uptake of black walnut seedlings  

Microsoft Academic Search

The effects of soil mixing (disturbance) and sterilization on nutrient solubility and uptake, and on growth of potted black walnut seedlings in forest and field soils were studied under glasshouse conditions. Seedlings were grown for 16 weeks in soils that were either disturbed or undisturbed only, and in combination with two methods of sterilization.Both pre? and post?harvest soil data showed

Felix Ponder Jr

1981-01-01

201

Energy biomass tree seedling production study. Fuels from woody biomass. Progress report, September 1978-January 1980  

SciTech Connect

The research to date has centered around the establishment of baseline growing conditions for a number of species of tree seedlings, primarily deciduous hardwoods. As these baseline conditions were established for each specie, the shoot and root environments were manipulated in an attempt to establish techniques to increase seedling growth and reduce production times. Seedlings were outplanted in an attempt to establish baseline survival rates for seedlings grown in totally controlled environments. Studies to determine the optimum container for tree seedling production have been run and will continue as other containers are identified and made available. The most significant of the research results has been in the maximization of seedling growth. Seedling production times have been decreased in some species by as much as 50% under the baseline production times. Controlled environment production techniques provide for plant densities as high as 144 seedlings per square foot of growing space. Investigations of growing media indicate a significant species specific responses. Preliminary results of outplanting indicate survival rates as high as 90% plus.

Foote, K.R.

1980-03-01

202

Leaf heteroblasty is not an adaptation to shade: seedling anatomical and physiological responses to light  

Microsoft Academic Search

Heteroblastic plants produce markedly different leaf morphologies between juvenile and adult stages, while homoblastic plants exhibit little or gradual changes. We tested the hypothesis that the leaf morphology of the seedling stage of New Zealand heteroblastic species is advantageous in dealing with low light levels found in forest understorey. We used four independent contrasts of heteroblastic and homoblastic seedlings from

Harshi K. Gamage; Linley Jesson

2007-01-01

203

Effect of Zinc on Cadmium Toxicity-Induced Oxidative Stress in Winter Wheat Seedlings  

Microsoft Academic Search

Two hydroponic experiments were conducted to investigate the antioxidant response of winter wheat (Triticum aestivum L.) to cadmium (Cd)-zinc (Zn) interactions, Seedlings of winter wheat (cv. Yuandong 977), were grown in modified Hoagland nutrient solution with the addition of increasing concentrations of Cd (0, 10, 25, 50 ?M). In experiment 2, the seedlings of the same cultivar were treated with

Z.-Q. Zhao; Y.-G. Zhu; R. Kneer; S. E. Smith

2005-01-01

204

Growth and nutrient uptake of coniferous seedlings: Comparison among 10 species at various seedbed densities  

Microsoft Academic Search

The evaluation of biomass production and uptake of N, P, K, Ca, and Mg for various plant components (roots, stems, and foliage) and totals by 10 species of 2-0 coniferous seedlings grown at a controlled range of densities in a highly productive forest nursery documents considerable differences among species and seedling parameters. The species are ranked by biomass and nutrient-element

Norman A. Richards; Albert L. Leaf; Donald H. Bickelhaupt

1973-01-01

205

Effect of aluminum on the growth and nutrition of tulip-poplar seedlings  

Microsoft Academic Search

Atmospheric deposition of nitrogen and sulfate is acidifying some ecosystems, potentially increasing the availability of aluminum in the soil solution. The effects of Al on tulip-poplar ( Liriodendron tulipifera L.) were investigated with seedlings grown in sand culture. Seedlings were exposed to Al at four concentrations ranging from 0 to 800 µM. Reductions of 77% in shoot biomass and 71%

Heidi B. Lux; Jonathan R. Cumming

1999-01-01

206

Seedling populations and regeneration of woody species in dry Afromontane forests of Ethiopia  

Microsoft Academic Search

The composition and density of seedlings, as well as height class distribution of woody species, were studied at two dry Afromontane forests in Ethiopia. A total of 40 species were recorded at Gara Ades and 41 at Menagesha forests. The density was 16 290 and 32 650 seedlings\\/ha at Gara Ades and Menagesha, respectively. A few species were not represented

Demel Teketay

1997-01-01

207

Seedling growth of Mora gonggrijpii, a large seeded climax species, under different soil and light conditions  

Microsoft Academic Search

Mora gonggrijpii seedlings were harvested on two soil types in small gaps and in the forest understorey. The seedlings appear to be intolerant of lateritic soil with poor drainage either as a result of poor aeration or reduction of the soil which is rich in iron and aluminium. Biomass allocation is not greatly affected on the lateritic soil as compared

Hans Steege

1994-01-01

208

An analysis of structure of tree seedling populations on a Lahar  

Microsoft Academic Search

The structure of a tree seedling population is dependent on the interaction of several processes including seed dispersal, germination, survival, and competition on a physical landscape. Structural components (composition, size distributions, spatial distributions, age distributions, density, and history) of a tree seedling population on the Muddy River Lahar on the east side of Mount St. Helens were examined over a

David R. Larsen; Lawrence C. Bliss

1998-01-01

209

Soil temperature effects on emergence and survival of Iris lactea seedlings  

Microsoft Academic Search

Iris lactea is a perennial herbaceous plant that is rapidly gaining popularity in gardens and for vegetation regeneration in its native northern China. However, its seeds have a high level of apparent dormancy with seedling emergence percentages being <5% under natural field conditions. An experiment was conducted to investigate the effects of soil temperature on seedling emergence. Treatments involved three

D. Huang; J. G. Han; W. L. Wu; J. Y. Wu

2008-01-01

210

Growth and photosynthesis of seedling of five bottom land tree species following nutrient enrichment  

Microsoft Academic Search

Land management practices are increasingly focusing on the use of native plant communities to filter wastewater. Nutrient uptake from these effluents may affect overall growth and physiology. We examined the effects of increased nutrient levels on the seedlings of five species of bottomland trees. Seedlings of Carpinus caroliniana Walter. (hornbeam), Pinus serotina Michaux (pond pine), Acer rubrum L. (red maple),

M. R. Vaitkus; T. G. Ciravolo; K. W. McLeod; E. M. Mavity; K. L. Novak

1993-01-01

211

Frequency Distribution of Lateral Roots of 1-0 Bare-Root White Oak Seedlings.  

National Technical Information Service (NTIS)

Frequency distributions of seedlings from three white oak mother trees were similar when seedling populations were stratified by first-order lateral roots with diameter approximately equals 1 mm at proximal end. The root-collar diameter, height, and top a...

P. P. Kormanik J. L. Ruehle H. D. Muse

1989-01-01

212

Effects of proline on copper transport in rice seedlings under excess copper stress  

Microsoft Academic Search

Copper exposure affects water flux and ion path in rice seedlings. To characterize the factors related to Cu transport in response to Cu exposure, rice (Oryza sativa cv. Taichung Native 1) seedlings grown by hyperculture were subjected to excess CuSO4 treatments, and Cu transport, water flux (transpiration rate and xylem sap extrusion), and proline level were assessed. Excess Cu decreased

Chien-Teh Chen; Tsai-Huei Chen; Kuo-Fu Lo; Chih-Yu Chiu

2004-01-01

213

Release of naturally established white pine seedlings from competition: An objective field index  

Microsoft Academic Search

Gap cutting has been recently prescribed in Quebec to favor the regeneration of midtolerant species such as white pine. However, this new practice may lead to increased competition, jeopardizing the survival of established seedlings. One important question, therefore, is how much care will be required to ensure that the seedlings will reach the sapling stage. More importantly, a practical field

P. a Nolet; D. a Bouffard; F.a b Lorenzetti

2006-01-01

214

Acclimation to frost alters proteolytic response of wheat seedlings to drought  

Microsoft Academic Search

A comparative examination of cysteine proteinases in winter wheat (Triticum aestivum L.) seedlings differing in sensitivity to frost and drought revealed many similarities and differences in response to water deprivation. Azocaseinolytic activity was enhanced under water deficiency, but the enhancement was significantly lower in the tolerant genotype (Kobra cultivar). On the contrary, acclimation of wheat seedlings at low temperature had

Ma?gorzata Grudkowska; Barbara Zagda?ska

2010-01-01

215

Effects of seed hydropriming in presence of exogenous proline on chilling injury limitation in Vigna radiata L. seedlings  

Microsoft Academic Search

Three-day-old seedlings (t\\u000a 0 stage) of Vigna radiata (L.) Wilczek obtained from seeds hydroprimed (H) and hydroprimed with proline (HPro) were examined. H and HPro slightly improved\\u000a mung bean seed germination and seedlings growth at 5°C. The best growth was observed in the seedlings obtain from HPro5 (5 mM)\\u000a seeds in comparison with the seedlings obtained from the control-non-primed seeds and

M. M. Posmyk; K. M. Janas

2007-01-01

216

Effects of Kinetin, IAA, and Gibberellin on Ethylene Production, and Their Interactions in Growth of Seedlings.  

PubMed

Kinetin in concentrations of 10(-8) to 10(-4)m, stimulated ethylene production in 3 and 4-day old etiolated seedlings of Alaska pea (Pisum sativum L. var. Alaska). Seedlings of other species responded similarly. The response to kinetin depended on the age of the seedlings.Kinetin alone did not influence ethylene production in 6-day old stem sections, but it greatly increased the enhancing effect of IAA.Gibberellic acid had no effect on ethylene production by pea seedlings during the first 6 days of growth. Ethylene and gibberellic acid are antagonistic in their effects on growth of the seedlings; ethylene interfered severely with the action of gibberellic acid but did not completely suppress it.The inhibitors cycloheximide, cupferron, and N-ethylmaleimide, caused considerable inhibition of kinetin-induced ethylene production but were much less effective in the endogenous ethylene-forming system. PMID:16657004

Fuchs, Y; Lieberman, M

1968-12-01

217

[Induction of chilling tolerance and heat shock protein synthesis in rice seedlings by heat shock].  

PubMed

Heat shock applied to germinated rice seeds increased the chilling tolerance of seedlings. Comparison with the control, brief heat shock applied before chilling at 4 degrees C for 2 days and recovery at 25 degrees C for another 2 days decreased the permeability of cellular membranes and increased the content of proline in rice seedlings. Heat shock applied before chilling also increased the activities of superoxide dismutase, catalase, and peroxidase and the content of ascorbate in rice seedlings. In contrast, the lipoxygenase activity and the malondialdehyde content in the heat-shocked rice seedlings were lower than those in the control. Germinated rice embryos synthesized heat shock proteins of Mr 78, 70, 64, 46, 38, 24, 17 and 16 kD during heat shock. The results of Western blot suggested that the binding protein (Bip) of HSP70 play an important role in protecting the rice seedling against chilling damage. PMID:15599046

Huang, Shang-Zhi; Huang, Xiang-Fu; Lin, Xiao-Dong; Zhang, Yi-Shun; Liu, Jun; Fu, Jia-Rui

2004-04-01

218

[Physiological characteristics of rice seedlings roots under aluminum stress].  

PubMed

A hydroponic experiment was conducted with the four-leaf stage seedlings of aluminum (Al)-susceptible rice variety IR24 and Al-tolerant rice varieties Jingyou 725 and Liangyoupeijiu to study the physiological characteristics of the seedlings roots under effects of 0, 0.5 mmol x L(-1), and 7.5 mmol x L(-1) of Al. Under the stress of 7.5 mmol Al x L(-1), Al-tolerant varieties had a far lesser decrement of root vigor than Al-susceptible variety, while the Al-susceptible variety had a higher root mitochondria H2O2 content than Al-tolerant varieties. Al stress induced a lesser increment of CAT activity in the root mitochondria of all tested varieties. With the increasing Al concentration, the root mitochondria POD activity of IR24 and Jingyou 725 decreased after an initial increase while that of Liangyoupeijiu was increasing, and the root mitochondria APX activity of IR24 decreased after an initial increase while that of Jingyou 725 and Liangyoupeijiu was increasing. The root glutamic acid content of all tested varieties showed an increase-decline trend, and their citric acid content decreased while PEP content increased. The ratio of cyanide-resistant respiration rate to total respiration rate of Al-tolerant Jingyou 725 and Liangyoupeijiu increased obviously, compared with that of Al-susceptible IR24. PMID:19899473

Xie, Guo-Sheng; Shi, Rui-Hong; Pang, Zhen-Wu; Cai, Ke-Tong

2009-07-01

219

PICKLE is a repressor in seedling de-etiolation pathway  

PubMed Central

Light plays a vital role in seedling de-etiolation during which it remarkably inhibits hypocotyl growth and promotes cotyledon opening and the synthesis of chlorophyll and anthocyanin. After light perception, photoreceptors act to repress two main branches of the light signaling, PIFs and COP1-HY5. We recently identified PKL/EPP1, a chromatin remodeling factor, as a new component in regulating light-mediated hypocotyl growth. In this study, we found that EPP1 acts additively with SPA1 to repress seedling de-etiolation. Moreover, the expression of EPP1 is downregulated specifically in the hypocotyl region of the cop1 mutant compared with that of the wild type. We further found that EPP1 drastically inhibits both the protein and transcript levels of HY5, but not vice versa, indicating that HY5 acts downstream of EPP1. We thus propose a model in which EPP1 defines a new repressor and mediates a distinct signaling pathway of photomorphogenesis.

Jing, Yanjun; Lin, Rongcheng

2013-01-01

220

Growth of dipterocarp seedlings in artificial gaps: An experiment in a logged-over rainforest in South Kalimantan, Indonesia  

Microsoft Academic Search

The objective of the study was to assess the feasibility of assisted natural regeneration of dipterocarp rainforest trees through gap simulation. Three hypotheses were tested: (1) opening of a gap enhances the rate of growth of dipterocarp seedlings; (2) growth of dipterocarp seedlings depends on gap size, being fastest in relatively small openings; and (3) growth of dipterocarp seedlings depends

Kari Tuomela; Jussi Kuusipalo; Lauri Vesa; Koerdi Nuryanto; A. P. S. Sagala; Göran Ĺdjers

1996-01-01

221

Root dipping of conifer seedlings shows little benefit in the northern Rocky Mountains. Forest Service research paper  

SciTech Connect

In the growth chamber, in the greenhouse, and in field studies, root dipping of bareroot lodgepole pine, ponderosa pine, Douglas-fir, and Engelmann spruce seedlings did not improve seedling survival, shoot growth, or root growth under dry soil conditions. Seedling root growth varied with tree species, soil type, and type of rood dip.

Sloan, J.P.

1994-07-01

222

Living long by staying small: stem layering as an adaptive life-history trait in shade-tolerant tree seedlings  

Microsoft Academic Search

Suppressed seedling banks are important in replacement dynamics in late-successional forests. However, demo- graphic properties of seedling populations are poorly known, and there has been little attention to traits that might affect fitness in suppressed seedlings. Acer saccharum Marsh., a shade-tolerant dominant in eastern North American forests, fre- quently develops adventitious roots along prostrate portions of stems (''layering''). Measurements of

Kerry D. Woods

2008-01-01

223

Phenotypic variation in seedlings of a “keystone” tree species ( Quercus douglasii ): the interactive effects of acorn source and competitive environment  

Microsoft Academic Search

Blue oak (Quercus douglasii) is a deciduous tree species endemic to California that currently exhibits poor seedling survival to sapling age classes. We used common garden techniques to examine how genetic variation at regional and local scales affected phenotypic expression in traits affecting oak seedling growth and survival. Between-population variation was examined for seedlings grown from acorns collected from a

K. J. Rice; D. R. Gordon; J. L. Hardison; J. M. Welker

1993-01-01

224

Identification of Calonectria colhounii Associated with Basal Stem Rot on Blueberry Seedlings Imported from the United States of America  

PubMed Central

Basal stem rot symptoms were found on blueberry seedlings imported from the United States of America in 2008. The fungus obtained from the diseased seedlings was identified as Calonectria colhounii based on morphological and molecular characteristics. The consignments of the blueberry seedlings infected with C. colhounii were destroyed to prevent introduction of the fungus to Korea.

Jeon, Nak Beom; Kim, Wan Gyu; Park, Myung Soo; Hyun, Ik-Hwa; Heo, Noh-Youl

2010-01-01

225

Effects of ferulic acid, an allelopathic compound, on leaf expansion of cucumber seedlings grown in nutrient culture  

Microsoft Academic Search

Cucumber seeds and seedlings at various ages (7–19 days old) were treated with a single treatment or multiple treatments (at 2-day intervals) of ferulic acid in nutrient culture. Ferulic acid treatments of cucumber seeds during stages of germination and radicle growth did not significantly reduce subsequent seedling growth. Ferulic acid treatments to seedlings reduced leaf area, leaf expansion, and dry

Udo Blum; Barry R. Dalton

1985-01-01

226

Species-specific effects of woody litter on seedling emergence and growth of herbaceous plants.  

PubMed

The effect of litter on seedling establishment can influence species richness in plant communities. The effect of litter depends on amount, and also on litter type, but relatively little is known about the species-specific effects of litter. We conducted a factorial greenhouse experiment to examine the effect of litter type, using two woody species that commonly co-occur in boreonemoral forest--evergreen spruce (Picea abies), deciduous hazel (Corylus avellana), and a mixture of the two species--and litter amount--shallow (4 mm), deep (12 mm) and leachate--on seedling emergence and biomass of three understorey species. The effect of litter amount on seedling emergence was highly dependent on litter type; while spruce needle litter had a significant negative effect that increased with depth, seedling emergence in the presence of hazel broadleaf litter did not differ from control pots containing no litter. Mixed litter of both species also had a negative effect on seedling emergence that was intermediate compared to the single-species treatments. Spruce litter had a marginally positive (shallow) or neutral effect (deep) on seedling biomass, while hazel and mixed litter treatments had significant positive effects on biomass that increased with depth. We found non-additive effects of litter mixtures on seedling biomass indicating that high quality hazel litter can reduce the negative effects of spruce. Hazel litter does not inhibit seedling emergence; it increases seedling growth, and creates better conditions for seedling growth in mixtures by reducing the suppressive effect of spruce litter, having a positive effect on understorey species richness. PMID:22028890

Koorem, Kadri; Price, Jodi N; Moora, Mari

2011-01-01

227

Differential seed and seedling predation by crabs: impacts on tropical coastal forest composition.  

PubMed

Recently, the importance of seed predation by crabs on mangrove species distributions and densities has been established by several studies. In a tropical coastal terrestrial forest in Costa Rica, we investigated the relative importance of predation by land crabs, Gecarcinus quadratus, and hermit crabs, Coenobita compressus, on measured forest composition through a series of seed removal and seedling establishment experiments. We also used natural light-gaps and adjacent non-gap sites to test how canopy cover affects crab predation (seed removal) and seedling establishment. We found fewer tree species (S=18) and lower densities (seedlings, saplings, and adults) in the coastal zone within 100 m of coastline, than in the inland zone (S=59). Land crab densities were higher in the coastal zone (3.03+/-1.44 crabs m(-2)) than in the inland zone (0.76+/-0.78 crabs m(-2)), and hermit crabs were not present in the inland zone. Seed removal and seedling mortality also were higher in the coastal zone than in the inland zone, and in the open controls than in the crab exclosures. Mortality of seeds and seedlings was two to six times higher in the controls than exclosures for four of the five experiments. Crabs preferred seeds and younger seedlings over older seedlings but showed no species preferences in the seed (Anacardium excelsum, Enterolobium cyclocarpum, and Terminalia oblonga) and seedling (Pachira quinata and E. cyclocarpum) stages. We conclude that the observed differences in tree densities were caused by differential crab predation pressure along the coastal gradient, while the differences in species composition were due to predator escape (satiation) by seed quantity. Canopy cover did not affect seed removal rates, but did affect seedling survival with higher mortality in the non-gap versus gap environments. In summary, crab predation of seeds and seedlings, and secondarily canopy cover, are important factors affecting tree establishment in terrestrial coastal forests. PMID:15349766

Lindquist, Erin Stewart; Carroll, C Ronald

2004-12-01

228

Anti-cigarette herbal formulation as an antidote to tobacco  

US Patent & Trademark Office Database

The present invention provides a novel nicotine free anticigarette herbal formulation as an anti-dote to the poisoning effects of tobacco products such as Cigarettes, Gutka, Pan masala and other similar tobacco related products. Formulation(s) comprises of sterilized dried plant powder/extracts together with the conventional additives to form the oral dosage forms, which include tablets, capsules, syrup and powders ready for suspension and mouth spray. The anti tobacco addiction herbal formulation comprises of Sesbania grandiflora, Catharanthus roseus, Ocimum sanctum, Myristica fragrans, Elettaria cardamomum, Carum copticum, Syzygium aromaticum, Cinnamomum tamala, Acorus calamus, Zingiber officinale, Piper nigrum, Cinnamomum zeylanicum, Cuminum cyminum, Nigella sativum, Cinnamomum camphora, Piper longum Ocimum gratissimum and Hemidesmus indicus.

2009-05-19

229

Can NPK fertilizers enhance seedling growth and mycorrhizal status of Tuber melanosporum-inoculated Quercus ilex seedlings?  

PubMed

Although successful cultivation of the black truffle (Tuber melanosporum) has inspired the establishment of widespread truffle orchards in agricultural lands throughout the world, there are many unknowns involved in proper management of orchards during the 6-10 years prior to truffle production, and there are conflicting results reported for fertilizer treatments. Here, we systematically evaluate the combined effects of nitrogen, phosphorous, and potassium with different doses of each element, applied to either foliage or roots, on plant growth parameters and the mycorrhizal status of outplanted 3-year-old seedlings in five experimental Quercus ilex-T. melanosporum orchards. Fertilization did not significantly improve seedling aboveground growth, but the plants treated with the fertilizer 12-7-7 applied to the roots (HNr) displayed longer field-developed roots. Only the fertilizer with the highest dose of K (10-6-28) applied to the foliage (HKf) increased the probability of fine root tip colonization by T. melanosporum in field-developed roots. However, the plants treated with the same fertilizer applied to the soil (HKr) presented the highest probability for colonization by other competing mycorrhizal soil fungi. Potassium seems to have an important role in mycorrhizal development in these soils. Apart from T. melanosporum, we found 14 ectomycorrhizal morphotypes, from which seven were identified to species level, three to genus, two to family, and two remained unidentified by their morphological characteristics and DNA analyses. PMID:20033737

Suz, Laura M; Martín, María P; Fischer, Christine R; Bonet, José A; Colinas, Carlos

2010-06-01

230

N2-fixation and seedling growth promotion of lodgepole pine by endophytic Paenibacillus polymyxa.  

PubMed

We inoculated lodgepole pine (Pinus contorta var. latifolia (Dougl.) Engelm.) with Paenibacillus polymyxa P2b-2R, a diazotrophic bacterium previously isolated from internal stem tissue of a naturally regenerating pine seedling to evaluate biological nitrogen fixation and seedling growth promotion by this microorganism. Seedlings generated from pine seed inoculated with strain P2b-2R were grown for up to 13 months in a N-limited soil mix containing 0.7 mM available N labeled as Ca((15)NO3)2 to facilitate detection of N2-fixation. Strain P2b-2R developed a persistent endophytic population comprising 10(2)-10(6) cfu g(-1) plant tissue inside pine roots, stems, and needles during the experiment. At the end of the growth period, P2b-2R had reduced seedling mortality by 14 % and (15)N foliar N abundance 79 % and doubled foliar N concentration and seedling biomass compared to controls. Our results suggest that N2-fixation by P. polymyxa enhanced growth of pine seedlings and support the hypothesis that plant-associated diazotrophs capable of endophytic colonization can satisfy a significant proportion of the N required by tree seedlings growing under N-limited conditions. PMID:23420205

Anand, Richa; Grayston, Susan; Chanway, Christopher

2013-08-01

231

Establishment of Ulmus pumila seedlings on steppe slopes of the northern Mongolian mountain taiga  

NASA Astrophysics Data System (ADS)

The potential of Siberian elm ( Ulmus pumila) to regenerate from seeds was experimentally studied on south-facing slopes in the northern Mongolian mountain taiga. These slopes are covered with a vegetation mosaic of different steppe communities and small, savanna-like, U. pumila open woodlands. The hypothesis is tested that the xeric microclimate and high herbivore densities limit the success of seedling establishment in U. pumila and thereby prevent elm from complete encroachment of the grassland-dominated slopes. Seeds were sown and 2-yr-old seedlings were planted prior to the growing season. The water supply was manipulated by irrigation, as was the feeding pressure by caterpillars with an insecticide. Large herbivores were excluded by fencing. Seeds germinated throughout the summer, but the emerged seedlings did not survive for more than 2 or 3 weeks. Germination rates increased with increasing soil water content and decreasing soil temperatures. Many seeds were consumed by granivores. Most planted 2-yr-old seedlings survived the two growing seasons covered by the study. However, the seedlings suffered from feeding damage by insects (gypsy moth, grasshoppers) and small mammals, from nitrogen deficiency and, to a lesser degree, from drought. The results suggest that high susceptibility of newly emerged seedlings to environmental stresses is a serious bottle neck for U. pumila that prevents them from the formation of closed forests on northern Mongolia's steppe slopes, whereas the probability for seedling survival after this early stage is high.

Dulamsuren, Choimaa; Hauck, Markus; Nyambayar, Suran; Osokhjargal, Dalaikhuu; Leuschner, Christoph

2009-09-01

232

Herbivory and seedling performance in a fragmented temperate forest of Chile  

NASA Astrophysics Data System (ADS)

Forest fragmentation alters plant-animal interactions, including herbivory. Relying manipulative experiments, we test if the reduction in insect herbivory associated with forest fragmentation translates into increased seedling growth and survival of three tree common species ( Aristotelia chilensis, Cryptocarya alba and Persea lingue) in forest fragments and continuous forests in coastal Maulino forest, central Chile. Furthermore, we test if after protecting seedlings from herbivorous insects, plant performance is increased regardless of forest fragmentation. Nursery grown seedlings were transplanted into four forest fragments and a continuous forest during 2002. Insects, important herbivores in this forest, were excluded from half the seedlings by repeated applications of insecticides. Compared to continuous forests, in forest fragments, herbivory was reduced in all three species, seedling growth was greater in A. chilensis and C. alba but not in P. lingue, and survivorship was unaffected by herbivory or fragmentation in all three species. Protecting seedlings from insects reduced herbivory in the continuous forest to similar levels attained in the forest fragments. No change in herbivory results from by protecting seedlings in forest fragments. These results confirm that insects are important herbivores in the Maulino forest and also support the hypothesis that fragmentation can have strong indirect effects on plant communities as mediated through trophic interactions.

Simonetti, Javier A.; Grez, Audrey A.; Celis-Diez, Juan L.; Bustamante, Ramiro O.

2007-11-01

233

Retention of cotyledons is crucial for resprouting of clipped oak seedlings  

PubMed Central

Although resprouting plays an important role in facilitating persistence of damaged seedlings, the functional attributes of cotyledons and taproots during resprouting of 1-year oak seedlings are not well explored. In this study, cotyledons were removed from Quercus mongolica seedlings to explore resprouting in response to simulated disturbance as a function of shoot clipping, and to examine the resprouting ability in relation to timing of clipping and cotyledon removal. Isotope labeling experiments were also performed to evaluate contribution of the cotyledons and taproots to resprouting. Regardless of timing of shoot clipping, seedlings successfully resprouted provided their cotyledons were not detached. Clipped seedlings were less likely to resprout when cotyledons were removed. Seedlings clipped at earlier development stage exhibited higher resprouting capacity than those clipped at later stage. Cotyledon removal, more than timing of clipping, decreased the dry masses of newly-resprouted shoots. However, no significant influences of cotyledon removal and timing of clipping were found on the dry masses of roots, suggesting the importance of cotyledons for resprouting. Roots became functional and accumulated more soil nitrogen after shoot clipping and cotyledon removal, representing a double security-based strategy for the clipped seedlings to resprout despite the importance of cotyledons.

Yi, Xianfeng; Liu, Changqu

2014-01-01

234

Access to mycorrhizal networks and roots of trees: importance for seedling survival and resource transfer.  

PubMed

Mycorrhizal networks (MNs) are fungal hyphae that connect roots of at least two plants. It has been suggested that these networks are ecologically relevant because they may facilitate interplant resource transfer and improve regeneration dynamics. This study investigated the effects of MNs on seedling survival, growth and physiological responses, interplant resource (carbon and nitrogen) transfer, and ectomycorrhizal (EM) fungal colonization of seedlings by trees in dry interior Douglas-fir (Pseudotsuga menziesii var. glauca) forests. On a large, recently harvested site that retained some older trees, we established 160 isolated plots containing pairs of older Douglas-fir "donor" trees and either manually sown seed or planted Douglas-fir "receiver" seedlings. Seed- and greenhouse-grown seedlings were sown and planted into four mesh treatments that served to restrict MN access (i.e., planted into mesh bags with 0.5-, 35-, 250-microm pores, or without mesh). Older trees were pulse labeled with carbon (13CO2) and nitrogen (15NH4(15)NO3) to quantify resource transfer. After two years, seedlings grown from seed in the field had the greatest survival and received the greatest amounts of transferred carbon (0.0063% of donor photo-assimilates) and nitrogen (0.0018%) where they were grown without mesh; however, planted seedlings were not affected by access to tree roots and hyphae. Size of "donor" trees was inversely related to the amount of carbon transferred to seedlings. The potential for MNs to form was high (based on high similarity of EM communities between hosts), and MN-mediated colonization appeared only to be important for seedlings grown from seed in the field. These results demonstrate that MNs and mycorrhizal roots of trees may be ecologically important for natural regeneration in dry forests, but it is still uncertain whether resource transfer is an important mechanism underlying seedling establishment. PMID:19886489

Teste, François P; Simard, Suzanne W; Durall, Daniel M; Guy, Robert D; Jones, Melanie D; Schoonmaker, Amanda L

2009-10-01

235

Interactions between seedlings of Agave deserti and the nurse plant Hilaria rigida  

SciTech Connect

Seedlings of the succulent crassulacean acid metabolism (CAM) plant Agave deserti in the northwestern Sonoran Desert were found only in sheltered microhabitats, nearly all occurring under the canopy of a desert bunchgrass, Hilaria rigida. Apparently because soil surface temperatures can reach 71{degree}C in exposed areas, seedlings were generally located near the center or on the northern side of this nurse plant. Both species have shallow root systems, about half of the roots of H. rigida and all those for seedlings of A. deserti occurring above soil depths of 0.08 m. To examine competition for water between the nurse plant and an associated seedling, a three-dimensional model for root water uptake was developed. Predicted pre-dawn soil water potentials at the mean root depth and total shoot transpiration agreed well with field measurements. Simulated annual water uptake by a seedling of A. deserti was reduced {approx}50% when the seedling was moved from an exposed location to the center of the nurse plant. Shading by the nurse plant reduced total daily photosynthetically active radiation (PAR) by up to 74% compared with an exposed seedling. On the other hand, soil nitrogen under the canopy of H rigida was 60% higher than in exposed locations. Assuming that the effects of nitrogen, temperature, PAR, and soil water on net CO{sub 2} uptake are multiplicative, the predicted net CO{sub 2} uptake by a seedling of A. deserti under the nurse plant was only {approx}45% of that for an exposed seedling.

Franco, A.C.; Nobel, P.S. (Univ. of California, Los Angeles (USA))

1988-12-01

236

Organic nitrogen uptake of Scots pine seedlings is independent of current carbohydrate supply.  

PubMed

In boreal forests, seedling establishment is limited by various factors including soil nitrogen (N) availability. Seedlings may absorb N from soil in a variety of inorganic and organic forms; however, the energy and thus carbohydrate requirements for uptake and assimilation of N vary with N source. We studied the importance of current photoassimilates for the acquisition and allocation of different N sources by Scots pine (Pinus sylvestris (L.)) seedlings. Girdling was used as a tool to impair phloem transport of photoassimilates, and hence gradually deprive roots of carbohydrates. Seedlings were cultivated in a greenhouse on equimolar N concentrations of one of the N sources-arginine, ammonium or nitrate-and then girdled prior to a pulse-chase uptake experiment with isotopically labeled N sources. Girdling proved to be efficient in decreasing levels of soluble sugars and starch in the roots. Uptake rate of arginine N was highest, intermediate for ammonium N and lowest for nitrate N. Moreover, the uptake of arginine N was unaffected by girdling, while the uptake of the two inorganic N sources decreased to 45-56% of the ungirdled controls. In arginine-treated seedlings, 95-96% of the acquired arginine N resided in the roots, whereas a significant shift in the N distribution toward the shoot was evident in girdled seedlings treated with inorganic N. This spatial shift was especially pronounced in nitrate-treated seedlings suggesting that the reduction and following incorporation into roots was limited by the availability of current photoassimilates. These results suggest that there are energetic benefits for seedlings to utilize organic N sources, particularly under circumstances where carbohydrate supply is limited. Hence, these putative benefits might be of importance for the survival and growth of seedlings when carbohydrate reserves are depleted in early growing season, or in light-limited environments, such as those sustained by continuous cover forestry systems. PMID:23824240

Gruffman, Linda; Palmroth, Sari; Näsholm, Torgny

2013-06-01

237

Biosynthesis of trigonelline from nicotinate mononucleotide in mungbean seedlings.  

PubMed

To determine the biosynthetic pathway to trigonelline, the metabolism of [carboxyl-(14)C]nicotinate mononucleotide (NaMN) and [carboxyl-(14)C]nicotinate riboside (NaR) in protein extracts and tissues of embryonic axes from germinating mungbeans (Phaseolus aureus) was investigated. In crude cell-free protein extracts, in the presence of S-adenosyl-L-methionine, radioactivity from [(14)C]NaMN was incorporated into NaR, nicotinate and trigonelline. Activities of NaMN nucleotidase, NaR nucleosidase and trigonelline synthase were also observed in the extracts. Exogenously supplied [(14)C]NaR, taken up by embryonic axes segments, was readily converted to nicotinate and trigonelline. It is concluded that the NaMN-->NaR-->nicotinate-->trigonelline pathway is operative in the embryonic axes of mungbean seedlings. This result suggests that trigonelline is synthesised not only from NAD but also via the de novo biosynthetic pathway of pyridine nucleotides. PMID:17888466

Zheng, Xin-Qiang; Matsui, Ayu; Ashihara, Hiroshi

2008-01-01

238

Correlations between polyamine ratios and growth patterns in seedling roots  

NASA Technical Reports Server (NTRS)

The levels of putrescine, cadaverine, spermidine and spermine were determined in seedling roots of pea, tomato, millet and corn, as well as in corn coleoptiles and pea internodes. In all roots, putrescine content increased as elongation progressed, and the putrescine/spermine ratio closely paralleled the sigmoid growth curve up until the time of lateral root initiation. Spermidine and spermine were most abundant near the apices and declined progressively with increasing age of the cells. In the zone of differentiation of root hairs in pea roots, putrescine rose progressively with increasing age, while cadaverine declined. In both pea internodes and corn coleoptiles, the putrescine/spermidine ratio rises with increasing age and elongation. Thus, a block in the conversion of the diamine putrescine to the triamine spermidine may be an important step in the change from cell division to cell elongation.

Shen, H. J.; Galston, A. W.

1985-01-01

239

Salicylic Acid Alleviates the Cadmium Toxicity in Barley Seedlings1  

PubMed Central

Salicylic acid (SA) plays a key role in plant disease resistance and hypersensitive cell death but is also implicated in hardening responses to abiotic stressors. Cadmium (Cd) exposure increased the free SA contents of barley (Hordeum vulgare) roots by a factor of about 2. Cultivation of dry barley caryopses presoaked in SA-containing solution for only 6 h or single transient addition of SA at a 0.5 mm concentration to the hydroponics solution partially protected the seedlings from Cd toxicity during the following growth period. Both SA treatments had little effect on growth in the absence of Cd, but increased root and shoot length and fresh and dry weight and inhibited lipid peroxidation in roots, as indicated by malondialdehyde contents, in the presence of Cd. To test whether this protection was due to up-regulation of antioxidant enzymes, activities and transcript levels of the H2O2-metabolizing enzymes such as catalase and ascorbate peroxidase were measured in control and SA-treated seedlings in the presence or absence of 25 ?m Cd. Cd stress increased the activity of these enzymes by variable extent. SA treatments strongly or completely suppressed the Cd-induced up-regulation of the antioxidant enzyme activities. Slices from leaves treated with SA for 24 h also showed an increased level of tolerance toward high Cd concentrations as indicated by chlorophyll a fluorescence parameters. The results support the conclusion that SA alleviates Cd toxicity not at the level of antioxidant defense but by affecting other mechanisms of Cd detoxification.

Metwally, Ashraf; Finkemeier, Iris; Georgi, Manfred; Dietz, Karl-Josef

2003-01-01

240

Salicylic acid alleviates the cadmium toxicity in barley seedlings.  

PubMed

Salicylic acid (SA) plays a key role in plant disease resistance and hypersensitive cell death but is also implicated in hardening responses to abiotic stressors. Cadmium (Cd) exposure increased the free SA contents of barley (Hordeum vulgare) roots by a factor of about 2. Cultivation of dry barley caryopses presoaked in SA-containing solution for only 6 h or single transient addition of SA at a 0.5 mM concentration to the hydroponics solution partially protected the seedlings from Cd toxicity during the following growth period. Both SA treatments had little effect on growth in the absence of Cd, but increased root and shoot length and fresh and dry weight and inhibited lipid peroxidation in roots, as indicated by malondialdehyde contents, in the presence of Cd. To test whether this protection was due to up-regulation of antioxidant enzymes, activities and transcript levels of the H(2)O(2)-metabolizing enzymes such as catalase and ascorbate peroxidase were measured in control and SA-treated seedlings in the presence or absence of 25 microM Cd. Cd stress increased the activity of these enzymes by variable extent. SA treatments strongly or completely suppressed the Cd-induced up-regulation of the antioxidant enzyme activities. Slices from leaves treated with SA for 24 h also showed an increased level of tolerance toward high Cd concentrations as indicated by chlorophyll a fluorescence parameters. The results support the conclusion that SA alleviates Cd toxicity not at the level of antioxidant defense but by affecting other mechanisms of Cd detoxification. PMID:12746532

Metwally, Ashraf; Finkemeier, Iris; Georgi, Manfred; Dietz, Karl-Josef

2003-05-01

241

Vegetation management for reducing mortality of ponderosa pine seedlings from Thomomys spp  

USGS Publications Warehouse

The effects of vegetation management on Mazama pocket gopher activity and damage to ponderosa pine seedlings were studied using atrazine herbicide to alter the habitat. Atrazine treatments were applied to a large treatment unit and observed effects were compared to an untreated control unit. The greatly reduced forb and grass cover on the treated unit was associated with a corresponding decrease in pocket gopher activity. Times until seedlings first incurred gopher damage and overall survival of two cohorts of seedlings were greatly increased on the treated unit.

Barnes, V. G., Jr.; Anthony, M.; et al

1995-01-01

242

Ribosomal Changes during Induction of Cold Hardiness in Black Locust Seedlings 1  

PubMed Central

Protein synthesis has been implicated in the cold-hardening process. Ribosomes from cold hardy and nonhardy black locust (Robinia pseudoacacia L.) seedlings were compared to determine if cold acclimation is related to alteration of ribosomal structure. Ribosomal structure, as indicated by thermal melting profiles, appears to be altered during induction of hardiness. Two-dimensional polyacrylamide gel electrophoresis of ribosomal proteins indicates at least 17 proteins from hardy seedlings that are different from those of nonhardy seedlings. These different proteins may be partially responsible for the different thermal melting profiles observed. Images

Bixby, James A.; Brown, Gregory N.

1975-01-01

243

Interaction of light and gravitropism with nutation of hypocotyls of Arabidopsis thaliana seedlings  

NASA Technical Reports Server (NTRS)

Etiolated seedlings of Arabidopsis thaliana nutated under conditions of physiological darkness while about ten percent of monitored individuals exhibited regular elliptical nutation, circumnutation. Pre-irradiation with red light prevented occurrence of circumnutation without having an effect on the average rate of the nutational movement. Phototropic response of seedlings to unilateral blue light appeared to be superimposed over nutation. Throughout gravitropism, some seedlings continued to exhibit nutation suggesting that these two processes are independently controlled. Based on these results, we suggest that nutation in Arabidopsis probably is not controlled by the mechanism predicted by the theory of gravitropic overshoots.

Orbovic, V.; Poff, K. L.

1997-01-01

244

The Arabidopsis plastid-signalling mutant gun1 (genomes uncoupled1) shows altered sensitivity to sucrose and abscisic acid and alterations in early seedling development  

PubMed Central

Developing seedlings of the Arabidopsis gun1 (genomes uncoupled1) mutant, which is defective in retrograde plastid-to-nucleus signalling, show several previously unrecognized mutant phenotypes. gun1 seedlings accumulated less anthocyanin than wild-type seedlings when grown in the presence of 2% (w/v) sucrose, due to lower amounts of transcripts of early anthocyanin biosynthesis genes in gun1. Norflurazon and lincomycin, which induce retrograde signalling, further decreased the anthocyanin content of sucrose-treated seedlings, and altered the temporal pattern of anthocyanin accumulation. Lincomycin treatment altered the spatial pattern of sucrose-induced anthocyanin accumulation, suggesting that plastids provide information for the regulation of anthocyanin biosynthesis in Arabidopsis seedlings. The temporal pattern of accumulation of LHCB1 transcripts differed between wild-type and gun1 seedlings, and gun1 seedlings were more sensitive to sucrose suppression of LHCB1 transcript accumulation than wild-type seedlings. Growth and development of gun1 seedlings was more sensitive to exogenous 2% sucrose than wild-type seedlings and, in the presence of lincomycin, cotyledon expansion was enhanced in gun1 seedlings compared to the wild type. gun1 seedlings were more sensitive than wild-type seedlings to the inhibition of seedling growth and development by abscisic acid. These observations clearly implicate GUN1 and plastid signalling in the regulation of seedling development and anthocyanin biosynthesis, and indicate a complex interplay between sucrose and plastid signalling pathways.

Cottage, Amanda; Mott, Ellie K.; Kempster, Jennie A.; Gray, John C.

2010-01-01

245

Effect of mycorrhizal status of avocado seedlings on root rot caused by Phytophthora cinnamomi  

Microsoft Academic Search

Summary The mycorrhizal fungusGlomus fasciculatus stimulated growth of avocado seedlings in the presence or absence ofPhytophthora cinnamomi. It appeared thatG. fasciculatus had no effect upon infection byP. cinnamomi or subsequent disease development.

R. Mataré; M. J. Hattingh

1978-01-01

246

Comparative field study of growth and survival of Sierran conifer seedlings.  

National Technical Information Service (NTIS)

This study is a comparison of seedling growth and survival of seven species of conifers that make up the mid-elevation Sierra Nevada mixed conifer forest--Abies concolor, Abies magnifica, Calocedrus decurrens, Pinus jeffreyi, Pinus lambertiana, Pinus pond...

R. A. Kern

1996-01-01

247

Synthesis of Ectomycorrhizae on Northern Red Oak Seedlings in a Michigan Nursery.  

National Technical Information Service (NTIS)

Vegetative inoculum of the ectomycorrhizal fungus Suillus luteus was thoroughly mixed into fumigated nursery soil, and northern red oak seedlings of four families were evaluated one and two years after sowing for ectomycorrhizal development, growth, and n...

R. K. Dixon P. S. Johnson

1993-01-01

248

Amelioration of Cd toxicity by pretreatment of salicylic acid in Cicer arietinum L. seedlings.  

PubMed

In this study, the ameliorating effect of salicylic acid (SA), serving as a mediator for protecting plants, against cadmium (Cd) toxicity in Cicer arietinum was investigated. The seedlings of Cicer arietinum treated with increasing Cd concentrations (0, 25, 50, 100 microM ) inhibited seedling length, reduced fresh and dry weight, total chlorophyll, carotenoid content and fatty acid methyl ester content. Furthermore, the level of some important parameters like MDA, proline and GSH content related to oxidative stress increased in Cd treated seedlings. Leaves of seedlings pretreated with salicylic acid (0.5 mM), alleviated the toxic effects of Cd by increasing the growth parameters, photosynthetic pigments, GSH and FAME content and decreasing proline and MDA content respectively. The result of the present study reveals the protective role of salicylic acid against Cd toxicity in C. arietinum. PMID:24555342

Canakci, Songül; Dursun, Bahar

2013-11-01

249

Interaction between a dark septate endophytic isolate from Dendrobium sp. and roots of D. nobile seedlings.  

PubMed

Interactions between an isolate of dark septate endophytes (DSE) and roots of Dendrobium nobile Lindl. seedlings are reported in this paper. The isolate was obtained from orchid mycorrhizas on Dendrobium sp. in subtropical forest. The fungus formed typical orchid mycorrhiza in aseptic co-culture with D. nobile seedlings on modified Murashige-Skoog (MMS) medium. Anatomic observations of the infected roots showed that the DSE hyphae invaded the velamen layer, passed through passage cells in exodermis, entered the cortex cells, and then formed fungal pelotons of orchid mycorrhiza. D. nobile seedlings' plant height, stem diameter, new roots number and biomass were greatly enhanced by inoculating the fungus to seedlings. The fungus was identified as Leptodontidium by sequencing the polymerase chain reaction-amplified rDNA ITS1-5.8S-ITS2 (internal transcribed spacer (ITS)) regions and comparison with similar taxa. PMID:21452589

Hou, Xiao-Qiang; Guo, Shun-Xing

2009-04-01

250

Effects of salicylic acid on growth, biochemical constituents in pepper (Capsicum annuum L.) seedlings.  

PubMed

In the present study, the effect of different concentrations of salicylic acid which is an endogenous organic acid in plants and which is commonly cited as a hormone, on the growth and some other parameters of pepper (Capsicum annuum L. cv.) seedlings was investigated. The solutions were applied to the roots of seedlings using hydroponic method. In general, 1.5 mM concentration of salicylic acid had a stimulating effect while 5 and 10 mM concentrations had varying degrees of inhibitive effects on the seedlings. Although 0.3 mM SA application produced prominent results in the case of all parameters, the difference was not found statistically significant. The inhibitive effect produced by high SA was found much more dominant than the stimulating effect of low SA concentrations. Thus, it was established that SA had a bidirectional physiological effect on the seedlings in a concentration-dependent manner. PMID:21870633

Canakci, S

2011-02-15

251

Competitive Effects of Bluebunch Wheatgrass, Crested Wheatgrass, and Cheatgrass on Antelope Bitterbrush Seedling Emergence and Survival.  

National Technical Information Service (NTIS)

The competitive environment into which plant seedlings emerge often determines the survival and performance of these individuals. This study was designed to determine the effects of bluebunch wheatgrass (Pseudoroegneria spicata), crested wheatgrass (Agrop...

D. B. Hall V. J. Anderson S. B. Monsen

1999-01-01

252

Occurrence of Conifer Seedlings and Their Microenvironments on Disturbed Sites in Central Idaho.  

National Technical Information Service (NTIS)

Microsite seedbeds and covers were surveyed for six conifer species following various silvicultural site preparation combinations in three central Idaho habitat types. Seedling occurrence was related to seedbeds, cover, site preparation method, and silvic...

K. Geier-Hayes

1987-01-01

253

Biotic and Abiotic Mechanisms in the Establishment of a Northern Red Oak Seedlings: A Review.  

National Technical Information Service (NTIS)

The sustained presence of northern red oak (Quercus rubra) in forests throughout the eastern and central hardwood regions of the United States often depends on seed-origin reproduction. However, in some hardwood forests, small northern red oak seedlings m...

L. S. Gribko T. M. Schuler W. M. Ford

2002-01-01

254

Influence of Stomatic Aperture on Photosynthetic Activity of Bean-Seedlings Leaves.  

National Technical Information Service (NTIS)

The data of photosynthetic activity and stomatic aperture of bean-seedlings leaves, and the relations obtained with both results are showed. It has been observed that the product of photosynthetic activity by the resistance to transpiration measured by a ...

J. Fernandez Gonzalez J. Suarez Moya

1984-01-01

255

Gene expression in the soybean seed axis during germination and early seedling growth  

Microsoft Academic Search

Copy-DNA clones have been obtained that distinguish eight messenger mRNAs, moderately abundant in the axes of the germinating soybean (Glycine max (L.) Merr.) seedling. These clones have been used to characterize the size of the mRNAs and to anlyze the accumulation of the mRNAs at different time points and in different parts of the axis during germination and early seedling

K. Datta; H. Parker; V. Averyhart-Fullard; A. Schmidt; A. Marcus

1987-01-01

256

Magnetic field can alleviate toxicological effect induced by cadmium in mungbean seedlings.  

PubMed

To alleviate toxicological effect induced by cadmium in mungbean seedlings, seeds were divided into four groups: The controls groups (CK, without treatment), magnetic field treated groups (MF), cadmium treated groups (CS), and magnetic field treated followed by cadmium treated groups (MF + CS).The results showed: (i) Compared with the controls, cadmium stress resulted in enhancing in the concentration of malondialdehyde, H(2)O(2) and O(2-), and the conductivity of electrolyte leakage while decreasing in the nitrice oxide synthase (NOS) activity, the concentration of nitrice oxide (NO), chlorophyll and total carbon and nitrogen, the net photosynthetic rate, the stomatal conductance, the transpiration rate, the water use efficiency, the lateral number and seedlings growth except for intercellular CO(2) concentration increase. However, the seedlings treated with 600 mT magnetic field followed by cadmium stress the concentration of malondialdehyde, H(2)O(2) and O(2-), and the conductivity of electrolyte leakage decreased, while the above mentioned NO concentration, NOS activity, photosynthesis and growth parameters increased compared to cadmium stress alone. (ii) Compared with the cadmium stress (CS), the seedling growth were inhibited when the seeds were treated with NO scavenger (hemoglobin, HB) and inhibition of NO generating enzyme (sodium tungstate, ST), conversely, the seedling growth were improved by the NO donor sodium nitroprusside (SNP) and CaCl(2). In the case of the HB and ST treatment followed by magnetic field and then the seedling subjected to CS, the seedlings growth was better than that of hemoglobin (HB) followed by CS and ST followed by CS. The seeds were treated with SNP and CaCl(2) followed by MF, and then subjected to CS, the seedlings growth were better than that of SNP followed by CS, and CaCl(2) followed by CS. These results suggested that magnetic field compensates for the toxicological effects of cadmium exposure are related to NO signal. PMID:21400092

Chen, Yi-ping; Li, Ran; He, Jun-Min

2011-06-01

257

Effects of endomycorrhizas and phosphorus fertiliser on nodulation and acetylene reduction activity of white clover seedlings  

Microsoft Academic Search

Inoculation of white clover (Trifolium repens L.) with the mycorrhizal fungus Glomus tenuis (in the presence of Rhizobium trifolii) had no effect on nodule initiation over a wide range of soil phosphate levels. Acetylene reduction assays of seedlings 21–60-days-old showed that nitrogenase activity per unit plant phosphorus was the same in mycorrhizal and non-mycorrhizal seedlings. The results show that endomycorrhizal

J. R. Crush

1982-01-01

258

Inhibitions of cotton seedling growth by volatile ketones emitted by cover crop residues  

Microsoft Academic Search

Low-input, sustainable agriculture (LISA) systems can include soil incorporation of residues of weeds and legume cover crop species. However, both seed germination and seedling growth of crops, including cotton (Gossypium hirsutum L.), are inhibited by volatile organic compounds emitted by these residues during decomposition. A cotton seedling-growth assay was used to demonstrate that C4 through C9 ketones released by decomposing

Judith M. Bradow

1993-01-01

259

Seed germination and seedling growth in the arrow bamboo Fargesia qinlingensis  

Microsoft Academic Search

Improving natural regeneration of bamboos after they die following mass flowering is critical for conservation of giant pandas.\\u000a However, little is known about factors that affect seed germination and seedling growth of bamboos. We studied seed germination\\u000a and seedling growth in Fargesia qinlingensis, which mass flowered in a giant panda habitat in the Qinling Mountains of China in early 2000,

Wei Wang; Scott B. Franklin; Margaret C. Cirtain

2007-01-01

260

Photoreactivation of the UV light effects on growth of Scots pine ( Pinus sylvestris L.) seedlings  

Microsoft Academic Search

Ultraviolet-B light (UV-B) and ultraviolet-A light (UV-A) at higher doses exert a strong inhibitory (‘toxic’) effect on axis growth in Scots pine (Pinus sylvestris L.) seedlings. This effect is unrelated to control of growth rate by phytochrome. Rather, after a ‘toxic’ UV dose growth of the pine seedling no longer responded to phytochrome. Both, the effect of UV-B as well

E. Fernbach; H. Mohr

1992-01-01

261

Air pollutants affect the relative growth rate of hardwood seedlings. Forest service research paper (final)  

Microsoft Academic Search

One-year-old seedlings of yellow-poplar (Liriodendron tulipifera), eastern cottonwood (Populus deltoides), and white ash (Fraxinus americana) were divided into four groups. One group Served as the control, and the other groups were fumigated for 12 hours per day with either 0.1 ppm O3, 0.2 ppm SO2, or 0.1 ppm O3 plus 0.2 ppm SO2. Two or three seedlings of each species

1981-01-01

262

“HAIRY CANOLA” – Arabidopsis GL3 Induces a Dense Covering of Trichomes on Brassica napus Seedlings  

Microsoft Academic Search

Transformation with the Arabidopsis bHLH gene 35S:GLABRA3 (GL3) produced novel B. napus plants with an extremely dense coverage of trichomes on seedling tissues (stems and young leaves). In contrast, trichomes\\u000a were strongly induced in seedling stems and moderately induced in leaves of a hairy, purple phenotype transformed with a 2.2 kb\\u000a allele of the maize anthocyanin regulator LEAF COLOUR (Lc), but

M. Y. Gruber; S. Wang; S. Ethier; J. Holowachuk; P. C. Bonham-Smith; J. Soroka; A. Lloyd

2006-01-01

263

Involvement of quorum sensing and RpoS in rice seedling blight caused by Burkholderia plantarii.  

PubMed

Burkholderia plantarii is a plant pathogen responsible for causing rice seedling blight. The molecular mechanisms responsible for this pathogenicity are currently unknown. In this study, we report the identification and characterization of N-acyl homoserine lactone quorum sensing and the stationary phase RpoS sigma factor of B. plantarii. Both global regulatory systems are involved in causing rice seedling blight. This is the first report of gene regulators of B. plantarii implicated in the disease. PMID:16684109

Solis, Renando; Bertani, Iris; Degrassi, Giuliano; Devescovi, Giulia; Venturi, Vittorio

2006-06-01

264

THE VARIOUS MECHANISMS OF PHOTOSYNTHESIS LIMITATION IN HEAT-TREATED BARLEY SEEDLINGS OF DIFFERENT AGES  

Microsoft Academic Search

Summary. The effect of heat shock (40şC, 3 h) on the photosynthetic activity of 4-, 7- and 11-day-old barley seedlings was studied. The rate of CO2 gas exchange in young leaves was not changed under heat shock while in 11-day- old seedlings the high temperature affected both the average quantum yield and the shape of light response curves of photosynthesis.

N. L. Pshybytko; L. N. Kalituho; L. F. Kabashnikova

265

Rapid photosynthetic acclimation of Shorea johorensis seedlings after logging disturbance in Central Kalimantan  

Microsoft Academic Search

This study examined the photosynthetic acclimation of pre-existing Shorea johorensis (Dipterocarpaceae) seedlings to the change in conditions that occurs at the time of logging in Central Kalimantan, Indonesia.\\u000a The hypothesis was that the seedlings would be unable to acclimate beyond partially open conditions after canopy disturbance\\u000a caused by logging, therefore limiting the potential for regeneration in the most open areas.

M. J. Clearwater; R. Susilawaty; R. Effendi; P. R. van Gardingen

1999-01-01

266

Heat shock protein Hsp90-2 expression in the Arabidopsis thaliana seedlings under clinorotation  

NASA Astrophysics Data System (ADS)

Heat shock proteins 90 kDa (Hsp90) are abundant under normal conditions and induced by stress. This family is distinguished from other chaperones in that most of its substrates are signal transduction proteins. Previously, we determined some time-dependent increase in the Hsp90 level in pea seedlings in response to simulated microgravity that indicated a stress-reaction. However, expression of the individual members of the Hsp90 family have specific pattern. The purpose of this study was to investigate possible alterations in the gene expression pattern of cytosolic Hsp90-2 in Arabidopsis thaliana seedlings under 2D-clinorotation. To obtain detailed expression pattern of the HSP90-2 genes we used seeds that provides a resource of loss-of-function mutations gene expression patterns via translational fusions with the reporter gene, GUS (a line N 166718, NASC). There were two variants of the experiment: 1) seedlings grew under clinorotation for 10, 12, 14 d; 2) seedlings grew in the stationary conditions for 10 d followed by clinorotation for 3 h -at 22o C and 16h light cycle. The seedlings grown in the stationary conditions were used as a control. GUS staining showed that HSP90-2 expression was regulated during seedling development and affected by clinorotation in the heterozygous mutant plants. In the homozygous for the mutation plants, HSP90-2 expression was stable during seedling development and not affected by clinorotation. GUS staining was observed in cotyledons, leaves and hypocotyls of the seedlings (especially intense in vascular bundles), indicating intensive cellular processes with participation of this chaperone. Possible pathways of influence of clinorotation on HSP90-2 expression are discussed.

Kozeko, Liudmyla

267

Seedling establishment in a dynamic sedimentary environment: a conceptual framework using mangroves  

PubMed Central

1. Vegetated biogeomorphic systems (e.g. mangroves, salt marshes, dunes, riparian vegetation) have been intensively studied for the impact of the biota on sediment transport processes and the resulting self-organization of such landscapes. However, there is a lack of understanding of physical disturbance mechanisms that limit primary colonization in active sedimentary environments. 2. This study elucidates the effect of sediment disturbance during the seedling stage of pioneer vegetation, using mangroves as a model system. We performed mesocosm experiments that mimicked sediment disturbance as (i) accretion/burial of plants and (ii) erosion/excavation of plants of different magnitudes and temporal distribution in combination with water movement and inundation stress. 3. Cumulative sediment disturbance reduced seedling survival, with the faster-growing Avicennia alba showing less mortality than the slower-growing Sonneratia alba. The presence of the additional stressors (inundation and water movement) predominantly reduced the survival of S. alba. 4. Non-lethal accretion treatments increased shoot biomass of the seedlings, whereas non-lethal erosion treatments increased root biomass allocation. This morphological plasticity in combination with the abiotic disturbance history determined how much maximum erosion the seedlings were able to withstand. 5. Synthesis and applications. Seedling survival in dynamic sedimentary environments is determined by the frequency and magnitude of sediment accretion or erosion events, with non-lethal events causing feedbacks to seedling stability. Managers attempting restoration of mangroves, salt marshes, dunes and riparian vegetation should recognize sediment dynamics as a main bottleneck to primary colonization. The temporal distribution of erosion and accretion events has to be evaluated against the ability of the seedlings to outgrow or adjust to disturbances. Our results suggest that selecting fast-growing pioneer species and measures to enhance seedling growth or temporary reduction in sediment dynamics at the restoration site can aid restoration success for vegetated biogeomorphic ecosystems.

Balke, Thorsten; Webb, Edward L; van den Elzen, Eva; Galli, Demis; Herman, Peter M J; Bouma, Tjeerd J

2013-01-01

268

Ectomycorrhiza formation of Tricholoma matsutake isolates on seedlings of Pinus densiflora in vitro  

Microsoft Academic Search

Tricholoma matsutake forms ectomycorrhizas withPinus densiflora under field conditions. The present study aimed to test the ability ofT. matsutake isolates to form mycorrhizas with aseptic seedlings ofP. densiflora in vitro. Pine seeds were germinated aseptically on a nutrient agar medium, and pairs of 1-wk-old seedlings were transplanted\\u000a into polymethylpentene bottles containing autoclaved sphagnum moss\\/vermiculite substrate. The substrate was saturated with

Akiyoshi Yamadal; Ken Maeda; Masatake Ohmasa

1999-01-01

269

Lepidimoide Promotes Light-Induced Chlorophyll Accumulation in Cotyledons of Sunflower Seedlings  

Microsoft Academic Search

.   The effect of disaccharide lepidimoide on light-induced chlorophyll accumulation was studied in cotyledons of sunflower (Helianthus annuus L.) seedlings and detached cucumber (Cucumis sativus L.) cotyledons. From studies on the structure-activity relationships of lepidimoide, its analogs, and sucrose with respect\\u000a to light-induced chlorophyll accumulation in the cotyledons of sunflower seedlings, both lepidimoide and the free carboxylic\\u000a acid of lepidimoide

K. Yamada; H. Matsumoto; K. Ishizuka; K. Miyamoto; S. Kosemura; S. Yamamura; K. Hasegawa

1998-01-01

270

Impact of sunflower and mustard leave extracts on the growth and dark respiration of mustard seedlings  

Microsoft Academic Search

The subject of the study was investigation of impact of extracts from sunflower and mustard leaves on growth of mustard seedlings.\\u000a Seeds of mustard were germinated on water and then grew on aqueous extracts from sunflower or mustard leaves. The specific\\u000a thermal power during seedlings growth was measured by isothermal calorimetry. Changes in the chemical composition stimulated\\u000a by extracts were

Andrzej Skoczowski; Magdalena Tro?; Anna Baran; Ma?gorzata Baranska

2011-01-01

271

Significant contribution of boron stored in seeds to initial growth of rice seedlings  

Microsoft Academic Search

Rice plants are relatively insensitive to low boron environment. We examined the role of boron stored in seeds in growth of\\u000a rice seedlings in regard to its insensitivity to low boron condition. In experiments using seeds without the removal of the\\u000a endosperm, the effect of low boron treatments (0.18 and 0.03 ?M B) was not evident on growth of seedlings until

Shimpei Uraguchi; Toru Fujiwara

2011-01-01

272

In vitro biochemical evaluation of cadmium tolerance mechanism in callus and seedlings of Brassica juncea  

Microsoft Academic Search

In vitro grown callus and seedlings of Brassica juncea were treated with equimolar concentrations of cadmium and compared for their respective tolerance to cadmium. Calli cultures\\u000a were grown on Murashige and Skoog medium supplemented with ? 6-benzyl aminopurine (200 µg L?1, naphthalene acetic acid 200 µg L?1) and 2,4-dichloro-phenoxy acetic acid (65 µg L?1) while the seedlings grown on Hoagland's nutrient solution have

Gyan Singh Shekhawat; Kusum Verma; Sonali Jana; Kusum Singh; Preeti Teotia; Archana Prasad

2010-01-01

273

Beneficial roles of arbuscular mycorrhizas in citrus seedlings at temperature stress  

Microsoft Academic Search

Citrus, a cold-sensitive plant, often suffers from low temperature, which seriously affects citrus productivity. The objective of the study was to elevate the roles of an arbuscular mycorrhizal fungus, Glomus mosseae, in growth, photosynthesis, root morphology and nutrient uptake of citrus (Citrus tangerine) seedlings under temperature stress conditions. Three-month-old seedlings with or without G. mosseae were grown for 55 days

Qiang-Sheng Wu; Ying-Ning Zou

2010-01-01

274

Rapid Kinetic Analysis of Ethylene Growth Responses in Seedlings: New Insights into Ethylene Signal Transduction  

Microsoft Academic Search

Ethylene is a phytohormone that influences diverse processes in plants. Ethylene causes various changes in etiolated seedlings\\u000a that differ between species and include reduced growth of shoots and roots, increased diameter of shoots, agravitropic growth,\\u000a initiation of root hairs, and increased curvature of the apical hook. The inhibition of growth in etiolated seedlings has\\u000a become widely used to screen for

Brad M. Binder

2007-01-01

275

Chilling stress suppresses chloroplast development and nuclear gene expression in leaves of mung bean seedlings  

Microsoft Academic Search

Etiolated leaves of 28°C-dark-grown mung bean (Vigna radiata L. cv. 2937) seedlings fail to turn green after being shifted to a light and cold environment. At the visible phenotypic level, incapability of leaf greening is the only failure event for the de-etiolation of mung bean seedlings at low temperature. Ultrastructural studies revealed that chloroplast development was completely suppressed by chilling

Ming-Tzong Yang; Shu-Ling Chen; Chu-Yung Lin; Yih-Ming Chen

2005-01-01

276

Differences in growth and mineral nutrition of seedlings produced from ten white spruce seed orchards  

Microsoft Academic Search

To meet the needs for improved spruce seeds in the province of Quebec, Canada, 17 first-generation white spruce seed orchards\\u000a (SO) were established. These SOs are located in different bioclimatic domains and contain seed trees originating from geographically\\u000a and genetically distinct sources. To evaluate the influence of SO on seedling growth and morphology, seedlings produced with\\u000a seeds originating from the

S. Carles; M. S. Lamhamedi; J. Beaulieu; D. C. Stowe; H. A. Margolis

2011-01-01

277

Growth Retardant-Induced Changes in Phototropic Reaction of Vigna radiata Seedlings 1  

PubMed Central

The effect of growth retardants on phototropism has been studied in mung bean (Vigna radiata) seedlings. Ancymidol, tetcyclacis, and paclobutrazol inhibited phototropism while AMO 1618 and CCC were ineffective. The fluence-response relationships for phototropism of etiolated seedlings were similar to those previously described for monocots and other dicots. Ancymidol caused a shift in the maximum phototropic response to higher fluence of light. It is suggested that ancymidol may affect phototropism through an effect on the photoreceptor system.

Konjevic, R.; Grubisic, D.; Neskovic, Mirjana

1989-01-01

278

Root-Shoot lnteraction in the Greening of Wheat Seedlings Grown under Red Light  

Microsoft Academic Search

Wheat seedlings grown with roots exposed to constant red light (300-500 pmol m-* s-') did not accumulate chlorophyll in the leaves. In contrast, seedlings grown with their roots shielded from light accumulated chlorophylls. Chlorophyll biosynthesis could be induced in red-light-grown chlorophyll-deficient yellow plants by either reducing the red-light intensity at the root surface to 100 pmol m-'s-' or supplementing with

Baishnab C. Tripathy; Christopher S. Brown

279

Interaction between large herbivore activities, vegetation structure, and flooding affects tree seedling emergence  

Microsoft Academic Search

Tree establishment in grazed vegetation mosaics involves a series of early bottlenecks, including seed dispersal, germination,\\u000a seedling emergence, survival and growth. In a field experiment, we studied seedling emergence of two species with contrasting\\u000a recruitment strategies, Fraxinus excelsior and Quercus robur, in five structurally different vegetations: grazed and ungrazed grassland, ruderal pioneer vegetation, soft rush tussocks,\\u000a tall sedge mats and

Jan Van Uytvanck; Tanja Milotic; Maurice Hoffmann

2010-01-01

280

Alleviating effects of exogenous Gamma-aminobutiric acid on tomato seedling under chilling stress.  

PubMed

Low temperature during germination and early seedling growth is one of the most significant limiting factors in the productivity of plants. Tomato seedling germination is sensitive to chilling stress. Gamma-aminobutyric acid (GABA), as a non-protein amino acid, involved in various stress tolerances in plants. In this study, 5-day old tomato seedlings were exposed to chilling stress (2?±?0.05 °C for 48 h) and then the effects of 0, 100, 250, 500 and 750 ?molL(-1) concentrations of GABA on electrolyte leakage, proline and malondialdehyde (MDA) content were investigated. The resultS showed that the antioxidant enzyme activity, electrolyte leakage, MDA and proline content were significantly reduced by GABA treatments. However under chilling stress seedlings treated with GABA exhibited significantly higher sugar and proline contents as compared to un-treated seedlings. These results suggest that GABA treatment protects tomato seedlings from chilling stress by enhancing some antioxidant enzymes activity and reducing MDA content which results in maintaining membrane integrity. PMID:24554847

Malekzadeh, Parviz; Khara, Jalil; Heydari, Reza

2014-01-01

281

Drought stress alters the concentration of wood terpenoids in Scots pine and Norway spruce seedlings.  

PubMed

Drought is known to have an impact on the resistance of conifers to various pests, for example, by affecting resin flow in trees. Little is known, however, about the quantitative and qualitative changes in resin when trees are growing in low moisture conditions. We exposed Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) seedlings to medium and severe drought stress for two growing seasons and analyzed the monoterpenes and resin acids in the main stem wood after two years of treatment. In addition to secondary chemistry, we measured the level of nutrients in the needles and the growth response of seedlings. After the first year of treatment, drought stress did not affect the growth of seedlings, but in the second year, shoot growth was retarded, especially in Scots pine. In both conifer species, severe drought increased the concentrations of several individual monoterpenes and resin acids. Total monoterpenes and resin acids were 39 and 32% higher in severe drought-treated Scots pine seedlings than in the controls, and 35 and 45% higher in Norway spruce seedlings. In Scots pine needles, the concentrations of nitrogen and phosphorus increased, while magnesium and calcium decreased compared to controls. In Norway spruce needles, nutrient concentrations were not affected. The results suggest that drought stress substantially affects both the growth of conifers and the chemical quality of the wood. We discuss the potential trade-off in growth and defense of small conifer seedlings. PMID:14584671

Turtola, Satu; Manninen, Anne-Marja; Rikala, Risto; Kainulainen, Pirjo

2003-09-01

282

Effect of CO2 laser radiation on physiological tolerance of wheat seedlings exposed to chilling stress.  

PubMed

To determine the effect of CO(2) laser pretreatment of wheat seeds on the physiological tolerance of seedlings to chilling stress, wheat seeds were exposed to CO(2) laser radiation for 300 s. After being cultivated for 48 h at 25 degrees C, the wheat seedlings were subjected to chilling stress for 24 h. Selected physiological and biochemical parameters were measured in 6-day-old seedlings. We observed that chilling stress enhanced the concentrations of malondialdehyde and oxidized glutathione while decreasing the activities of nitric oxide synthase, catalase, peroxidase, superoxide dismutase and the concentrations of nitric oxide and glutathione in the wheat leaves compared with controls. When the chilling stress was preceded by CO(2) laser irradiation, the concentrations of malondialdehyde and oxidized glutathione were decreased while the activities of nitric oxide synthase, catalase, peroxidase, superoxide dismutase and the concentrations of nitric oxide and glutathione increased. Furthermore, chilling stress decreased the biomass, biophoton intensity and GHS/GSSG ratios of seedlings while these parameters increased when the seedlings were treated with CO(2) laser irradiation prior to the chilling stress. The results suggest that a suitable dose of CO(2) laser stimulation can enhance the physiological tolerance of wheat seedlings to chilling stress. PMID:20408975

Chen, Yi-Ping; Jia, Jing-Fen; Yue, Ming

2010-01-01

283

Influence of lanthanides on the antioxidative defense system in maize seedlings under cold stress.  

PubMed

The influence of LaCl(3), CeCl(3), and NdCl(3) on the antioxidative defense system in maize seedlings under cold stress was investigated. It was found that maize seedlings cultivated in cold stress developed distinct cold symptoms, and the plant growth was significantly inhibited as expected, while Ln-treated seedling growth was improved. Cold stress in maize seedlings also increased the permeability of plasma membrane, malondialdehyde as a degradation product of lipid peroxidation, and reactive oxygen species such as superoxide radicals and hydrogen peroxide, and decreased activities of the antioxidant enzymes such as superoxide dismutase, catalase, ascorbate peroxidase, and glutathione content; however, Ln treatments cultivated in cold stress decreased the permeability of plasma membrane, malondialdehyde, and reactive oxygen species, and increased activities of the antioxidative defense system. It implied that Ln could increase oxidative-stress resistance under cold stress. On the other hand, the assay of physiological and biochemical parameters demonstrated that Ce relieving chilling injury of maize seedlings caused by cold stress was most significant, medium in the Nd treatment, and last in the La treatment. These results suggested that the increase of cold resistance of maize seedlings caused by Ln might be closely related to its properties of 4f electron shell and variable valence. PMID:20737244

Wang, Ying; Zhou, Min; Gong, Xiaolan; Liu, Chao; Hong, Mengmeng; Wang, Ling; Hong, Fashui

2011-09-01

284

The Effects of Cadmium-Zinc Interactions on Biochemical Responses in Tobacco Seedlings and Adult Plants  

PubMed Central

The objective of the present study was to investigate the effects of cadmium-zinc (Cd-Zn) interactions on their uptake, oxidative damage of cell macromolecules (lipids, proteins, DNA) and activities of antioxidative enzymes in tobacco seedlings as well as roots and leaves of adult plants. Seedlings and plants were exposed to Cd (10 µM and 15 µM) and Zn (25 µM and 50 µM) as well as their combinations (10 µM or 15 µM Cd with either 25 µM or 50 µM Zn). Measurement of metal accumulation exhibited that Zn had mostly positive effect on Cd uptake in roots and seedlings, while Cd had antagonistic effect on Zn uptake in leaves and roots. According to examined oxidative stress parameters, in seedlings and roots individual Cd treatments induced oxidative damage, which was less prominent in combined treatments, indicating that the presence of Zn alleviates oxidative stress. However, DNA damage found in seedlings, and lower glutathione reductase (GR) and superoxide dismutase (SOD) activity recorded in both seedlings and roots, after individual Zn treatments, indicate that Zn accumulation could impose toxic effects. In leaves, oxidative stress was found after exposure to Cd either alone or in combination with Zn, thus implying that in this tissue Zn did not have alleviating effects. In conclusion, results obtained in different tobacco tissues suggest tissue-dependent Cd-Zn interactions, which resulted in activation of different mechanisms involved in the protection against metal stress.

Tkalec, Mirta; Stefanic, Petra Peharec; Cvjetko, Petra; Sikic, Sandra; Pavlica, Mirjana; Balen, Biljana

2014-01-01

285

Resource availability and repeated defoliation mediate compensatory growth in trembling aspen (Populus tremuloides) seedlings  

PubMed Central

Plant ecologists have debated the mechanisms used by plants to cope with the impact of herbivore damage. While plant resistance mechanisms have received much attention, plant compensatory growth as a type of plant tolerance mechanisms has been less studied. We conducted a greenhouse experiment to evaluate compensatory growth for trembling aspen (Populus tremuloides) seedlings under varying intensities and frequencies of simulated defoliation, with or without nutrient enriched media. For the purpose of this study, changes in biomass production and non-structural carbohydrate concentrations (NSC) of roots and leaves were considered compensatory responses. All defoliated seedlings showed biomass accumulation under low defoliation intensity and frequency, regardless of resource availability; however, as defoliation intensity and frequency increased, compensatory growth of seedlings was altered depending on resource availability. Seedlings in a resource-rich environment showed complete compensation, in contrast responses ranged from undercompensation to complete compensation in a resource-limited environment. Furthermore, at the highest defoliation intensity and frequency, NSC concentrations in leaves and roots were similar between defoliated and non-defoliated seedlings in a resource-rich environment; in contrast, defoliated seedlings with limited resources sustained the most biomass loss, had lower amounts of stored NSC. Using these results, we developed a new predictive framework incorporating the interactions between frequency and intensity of defoliation and resource availability as modulators of plant compensatory responses.

Galvez, David A.; Zhang, Bin; Najar, Ahmed

2014-01-01

286

QTL studies reveal little relevance of chilling-related seedling traits for yield in maize.  

PubMed

Prolonged low temperature phases and short-term cold spells often occur in spring during the crucial stages of early maize (Zea mays L.) development. The effect of low temperature-induced growth retardation at the seedling stage on final yield is poorly studied. Therefore, the aim was to identify genomic regions associated with morpho-physiological traits at flowering and harvest stage and their relationship to previously identified quantitative trait loci (QTLs) for photosynthesis and morpho-physiological traits from the same plants at seedling stage. Flowering time, plant height and shoot biomass components at harvest were measured in a dent mapping population for cold tolerance studies, which was sown in the Swiss Midlands in early and late spring in two consecutive years. Early-sown plants exhibited chilling stress during seedling stage, whereas late-sown plants grew under favorable conditions. Significant QTLs, which were stable across environments, were found for plant height and for the time of flowering. The QTLs for flowering were frequently co-localized with QTLs for plant height or ear dry weight. The comparison with QTLs detected at seedling stage revealed only few common QTLs. A pleiotropic effect was found on chromosome 3 which revealed that a good photosynthetic performance of the seedling under warm conditions had a beneficial effect on plant height and partially on biomass at harvest. However, a high chilling tolerance of the seedling seemingly had an insignificant or small negative effect on the yield. PMID:18185918

Leipner, Jörg; Jompuk, Choosak; Camp, Karl-Heinz; Stamp, Peter; Fracheboud, Yvan

2008-02-01

287

Machine site preparation improves seedling performance on a high-elevation site in southwest Oregon  

SciTech Connect

Douglas-fir (Pseudotsuga menziesii) seedlings planted on areas receiving one of four site-preparation treatments (scarify, scarify/till, soil removal, and soil removal/till) and on unprepared control areas were compared for 5 yr at a high-elevation, nutrient-poor site in the western Siskiyou Mountains of southwest Oregon. Fifth-year survival of seedlings was at least 85% among machine-prepared plots, compared to 42% on control plots. Cover of competing vegetation remained less than 25% during the period for all machine treatments. In contrast, vegetation cover on control plots was 30% at the time of planting and increased to nearly 75% after 5 yr. Competing vegetation clearly impeded seedling performance. The effects of unusually droughty conditions at the time of planting in 1982 were examined further by interplanting additional seedlings in the soil-removal treatment in 1985. The interplanting was followed by more normal spring precipitation, and seedlings grew better over 5 yr than those planted in 1982. The slow recovery of competing vegetation and generally poor seedling growth on all treatments during both planting years are attributed to low soil fertility.

McNabb, D.H. (Oregon State Univ., Corvallis, OR (United States). Dept. of Forest Engineering); Baker-Katz, K.; Tesch, S.D. (Oregon State Univ., Corvallis, OR (United States). Dept. of Forest Science)

1993-07-01

288

Evidence of iron cyanides as supplementary nitrogen source to rice seedlings.  

PubMed

The effect of iron cyanides on activities of nitrate reductase (NR) and glutamine synthetase (GS) of plants was investigated. Young rice seedlings (Oryza sativa L. cv. XZX 45) were grown in the nutrient solutions containing KNO(3) or NH(4)Cl and treated with ferro-cyanide [K(4)Fe(CN)(6)] or ferri-cyanide [K(3)Fe(CN)(6)]. Total cyanide and free cyanide in solutions and in plant materials were analyzed. Activities of NR and GS in different parts of plants were assayed in vivo. Results indicated that all rice seedlings exposed to either ferro- or ferri-cyanide showed positive growth. The phyto-assimilation rates of both iron cyanide species by rice seedlings were positively correlated to the doses supplied. Seedlings grown on NO(3)(-) showed significantly higher assimilatory potential for both ferro- and ferri-cyanide than those on NH(4)(+). Rice seedlings grown on NH(4)(+)-containing nutrient solution accumulated more cyanide in plant materials, majority being in roots rather than shoots, than these grown on NO(3)(-)-containing nutrient solution, suggesting that the presence of ammonium (NH(4)(+)) in the nutrient solution caused a negative impact on botanical assimilation of both iron cyanides. Sensitivity of NR and GS in rice seedlings exposed to ferro- and ferri-cyanide was identical, where conspicuous effects were only observed at the highest concentration supplied. The evidence offered here suggests that both iron cyanides can be a supplementary source of nitrogen to plant nutrition. PMID:22684732

Yu, Xiao-Zhang; Shen, Ping-Ping; Gu, Ji-Guang; Zhou, Yan; Zhang, Fu-Zhong

2012-08-01

289

Litter mixture effects on tropical tree seedling growth--a greenhouse experiment.  

PubMed

Decomposing litter provides critical nutrients for plants, particularly in nutrient-poor ecosystems such as tropical forests. We hypothesised that decomposing litter improves the performance of a variety of tropical tree seedlings, and that this litter effect varies depending on the species of litter present in litter mixtures. We addressed these hypotheses with a large pot experiment manipulating a range of different litter mixtures of contrasting quality and using seedlings of four tree species from the Amazonian forest of French Guiana. In contrast to our initial hypothesis, decomposing litter had either neutral or negative impacts on seedling growth, despite strongly different growth rates, biomass allocation patterns and leaf and root traits among tree species. Tree species varied in their responses to litter additions, which were further modified by species identity of the added litter. Our data show litter species-specific effects on growth, biomass allocation and leaf and root traits of tropical tree seedlings. These results suggest that a net nutrient release from decomposing litter does not necessarily improve tree seedling growth, even under nutrient-limiting conditions. In conclusion, litter layer composition may affect seedling establishment and recruitment success beyond litter-derived plant nutrient availability, which may contribute to tree species composition and dynamics in the studied tropical forest. PMID:22289089

Coq, S; Weigel, J; Bonal, D; Hättenschwiler, S

2012-07-01

290

Bird predation enhances tree seedling resistance to insect herbivores in contrasting forest habitats.  

PubMed

According to the associational resistance hypothesis, neighbouring plants are expected to influence both the insect herbivore communities and their natural enemies. However, this has rarely been tested for the effects of canopy trees on herbivory of seedlings. One possible mechanism responsible for associational resistance is the indirect impact of natural enemies on insect herbivory, such as insectivorous birds. But it remains unclear to what extent such trophic cascades are influenced by the composition of plant associations (i.e. identity of 'associated' plants). Here, we compared the effect of bird exclusion on insect leaf damage for seedlings of three broadleaved tree species in three different forest habitats. Exclusion of insectivorous birds affected insect herbivory in a species-specific manner: leaf damage increased on Betula pendula seedlings whereas bird exclusion had no effect for two oaks (Quercus robur and Q. ilex). Forest habitat influenced both the extent of insect herbivory and the effect of bird exclusion. Broadleaved seedlings had lower overall leaf damage within pine plantations than within broadleaved stands, consistent with the resource concentration hypothesis. The indirect effect of bird exclusion on leaf damage was only significant in pine plantations, but not in exotic and native broadleaved woodlands. Our results support the enemies hypothesis, which predicts that the effects of insectivorous birds on insect herbivory on seedlings are greater beneath non-congeneric canopy trees. Although bird species richness and abundance were greater in broadleaved woodlands, birds were unable to regulate insect herbivory on seedlings in forests of more closely related tree species. PMID:21811874

Giffard, Brice; Corcket, Emmanuel; Barbaro, Luc; Jactel, Hervé

2012-02-01

291

Growth and lignification in seedlings exposed to eight days of microgravity  

NASA Technical Reports Server (NTRS)

Four-day-old pine seedlings and mung bean and oat seeds were prepared for flight on the third Space Transport System Mission (STS-3). The seedlings and seeds were planted in six mini-growth chambers (two chambers per species) which were placed in a plant growth unit (PGU). Another set of seedlings and seeds was prepared and placed in another PGU as the 1 g control. The flight PGU was positioned in the orbiter mid-deck locker area about 11 h prior to launch. The pine seedlings and germinating mung bean and oat seeds were exposed to 194 h of microgravity. The PGU was received at a temporary laboratory about 75 min post-landing. Plants were observed, photographed and the atmospheric gases analyzed at the landing site. The plants were then brought to our Houston laboratory where they were measured and analyzed for lignin and protein content and for phenylalanine ammonia-lyase (PAL) and peroxidase activities. Flight seedlings were shorter than the controls in all three species. Twenty-five to 40 per cent of the mung bean and oat roots were growing upward, and the mung beans showed signs of disorientation. Flight mung beans showed a significant reduction in lignin content in comparison to the controls, and PAL and peroxidase activities were reduced in flight pine seedlings. The results generally support the postulate that lignin synthesis is reduced in near-weightlessness and show other interesting findings.

Cowles, J. R.; Scheld, H. W.; Lemay, R.; Peterson, C.

1984-01-01

292

Influence of microhabitat on seedling survival and growth of the mediterranean seagrass posidonia oceanica (l.) Delile  

NASA Astrophysics Data System (ADS)

Early life history phases are crucial stages limiting species distribution and abundance, thus influencing assemblage composition in marine benthic environments. In seagrass systems the period between seed germination and establishment is one of the most vulnerable phases for plant development. This study analyzes the influence of microhabitat structure, in terms of substrate nature and algal canopy, on the persistence and growth over two years of seedlings of Posidonia oceanica, the dominant Mediterranean seagrass. Long time persistence of seedlings only occurred on microhabitats providing vegetated rocky substrates, with a maximum value of 81% on rock covered by Cystoseira spp. No seedling was found on unvegetated sand and gravel after the first year. Seedling growth resulted increased on rock covered by Halopteris spp. and Dilophus spp. than on rock covered by Cystoseira spp. Results suggest that high canopy onto a stable substrate enhances seedling persistence, probably because these allow the best anchorage by roots while hampering water flow. In contrast, turf algal cover promotes better seedling growth, possibly through higher light irradiance and nutrient availability. Our findings support the view that the understanding of the factors controlling early life processes is a necessary prerequisite for the comprehension of seagrass species distribution patterns, colonization and recovery potentials, which, in turn, can guide sound strategies for seagrass management and restoration.

Alagna, Adriana; Fernández, Tomás Vega; Terlizzi, Antonio; Badalamenti, Fabio

2013-03-01

293

Studies on the methods of identification of irradiated food I. Seedling growth test  

NASA Astrophysics Data System (ADS)

A seedling growth test for the identification of gamma irradiated edible vegetable seeds was described. The identification of gamma irradiated grape and the other seeds has been investigated. The purpose of this study was to develop an easy, rapid and practical technique for the identification of irradiated edible vegetable seeds. Seven different irradiated edible vegetable seeds as: rice ( Oryza sativa), peanut ( Arachis hypogaea), maize ( Zeamays), soybean ( Glycine max), red bean ( Phaseolus angularis), mung bean ( Phaseolus aureus) and catjang cowpea ( Vigna cylindrica) were tested by using the method of seedling growth. All of the edible vegetable seeds were exposed to gamma radiation on different doses, O(CK), 0.5, 1.0, 1.5, 2.0, 3.0, 5.0 kGy. After treatment with above 1.0 kGy dose to the seeds, the seedling rate was less than 50% compared with the control. Although the seedling rate of rice seeds can reached 58%, the seedling growth was not normal and the seedling leaves appeared deformed. The results by this method were helpful to identify gamma treatment of the edible vegetable seeds with above 1.0 kGy dose.

Qiongying, Liu; Yanhua, Kuang; Yuemei, Zheng

1993-07-01

294

Experimental Test for Facilitation of Seedling Recruitment by the Dominant Bunchgrass in a Fire-Maintained Savanna  

PubMed Central

Facilitative interactions between neighboring plants can influence community composition, especially in locations where environmental stress is a factor limiting competitive effects. The longleaf pine savanna of the southeastern United States is a threatened and diverse system where seedling recruitment success and understory species richness levels are regulated by the availability of moist microsites. We hypothesized that the dominant bunch grass species (Aristida stricta Michx.) would facilitate moist seedling microsites through shading, but that the effect would depend on stress gradients. Here, we examined the environmental properties modified by the presence of wiregrass and tested the importance of increased shade as a potential facilitative mechanism promoting seedling recruitment across spatial and temporal stress gradients. We showed that environmental gradients, season, and experimental water manipulation influence seedling success. Environmental properties were modified by wiregrass proximity in a manner that could facilitate seedling success, but we showed that shade alone does not provide a facilitative benefit to seedlings in this system.

Iacona, Gwenllian D.; Kirkman, L. Katherine; Bruna, Emilio M.

2012-01-01

295

Experimental test for facilitation of seedling recruitment by the dominant bunchgrass in a fire-maintained savanna.  

PubMed

Facilitative interactions between neighboring plants can influence community composition, especially in locations where environmental stress is a factor limiting competitive effects. The longleaf pine savanna of the southeastern United States is a threatened and diverse system where seedling recruitment success and understory species richness levels are regulated by the availability of moist microsites. We hypothesized that the dominant bunch grass species (Aristida stricta Michx.) would facilitate moist seedling microsites through shading, but that the effect would depend on stress gradients. Here, we examined the environmental properties modified by the presence of wiregrass and tested the importance of increased shade as a potential facilitative mechanism promoting seedling recruitment across spatial and temporal stress gradients. We showed that environmental gradients, season, and experimental water manipulation influence seedling success. Environmental properties were modified by wiregrass proximity in a manner that could facilitate seedling success, but we showed that shade alone does not provide a facilitative benefit to seedlings in this system. PMID:22792165

Iacona, Gwenllian D; Kirkman, L Katherine; Bruna, Emilio M

2012-01-01

296

Effects of nitrogen source and defoliation on growth and biological dinitrogen fixation of Gliricidia sepium seedlings.  

PubMed

Effects of four N sources and two defoliation treatments on growth and nitrogenase activity of Gliricidia sepium (Jacq.) Walp seedlings were studied in a greenhouse. All nutrients were supplied in irrigation water to the sterile growing medium. The N sources were: (1) 100 mg l(-1) of N supplied as NO(3) (-) (high-NO(3) (-)), (2) 50 mg l(-1) of N supplied as NO(3) (-) and inoculation with Rhizobium spp. medium-NO(3) (-)), (3)100 mg l(-1) of N supplied as NH(4)NO(3), and (4) inoculation with Rhizobium spp without mineral N (N(2)). At 35 weeks after sowing, mean total biomass was 130.5, 50.5, 22.9 and 17.4 g seedling(-1) in the NH(4)NO(3), N(2), medium-NO(3) (-) and high-NO(3) (-) treatments, respectively. The root/shoot ratio was high in all of the N treatments (1.73-2.77) because the seedlings had big taproots. The medium-NO(3) (-) treatment completely inhibited nodulation, whereas seedlings in the N(2) treatment were profusely nodulated. At 32 weeks after sowing, groups of seedlings in the N(2) and high-NO(3) (-) treatments were subjected to 50 or 100% defoliation. Closed-chamber acetylene reduction assays of intact root systems were conducted to compare nitrogenase activity at 7, 14 and 28 days after defoliation (DAD). At 7 and 14 DAD, nitrogenase activity of completely and partially defoliated seedlings was about 10 and 60%, respectively, of that of undefoliated controls. At 28 DAD, nitrogenase activity of completely defoliated seedlings was twice the predefoliation value, whereas nitrogenase activity of partially defoliated seedlings was only 87% of the predefoliation value. Recovery of nitrogenase activity was strongly correlated with foliage regrowth in the completely defoliated seedlings, but not in the partially defoliated seedlings. Abundant belowground C and N reserves in the large taproot probably contributed to the rapid recovery from defoliation. Accumulation of belowground biomass may also improve defoliation tolerance of mature trees. PMID:12651524

Nygren, Pekka; Vaillant, Victor; Desfontaines, Lucienne; Cruz, Pablo; Domenach, Anne Marie

2000-01-01

297

Multidimensional fluorescence microscopy of multiple organelles in Arabidopsis seedlings  

PubMed Central

Background The isolation of green fluorescent protein (GFP) and the development of spectral variants over the past decade have begun to reveal the dynamic nature of protein trafficking and organelle motility. In planta analyses of this dynamic process have typically been limited to only two organelles or proteins at a time in only a few cell types. Results We generated a transgenic Arabidopsis plant that contains four spectrally different fluorescent proteins. Nuclei, plastids, mitochondria and plasma membranes were genetically tagged with cyan, red, yellow and green fluorescent proteins, respectively. In addition, methods to track nuclei, mitochondria and chloroplasts and quantify the interaction between these organelles at a submicron resolution were developed. These analyzes revealed that N-ethylmaleimide disrupts nuclear-mitochondrial but not nuclear-plastids interactions in root epidermal cells of live Arabidopsis seedlings. Conclusion We developed a tool and associated methods for analyzing the complex dynamic of organelle-organelle interactions in real time in planta. Homozygous transgenic Arabidopsis (Kaleidocell) is available through Arabidopsis Biological Resource Center.

Kato, Naohiro; Reynolds, Dexter; Brown, Matthew L; Boisdore, Marietta; Fujikawa, Yukichi; Morales, Andrea; Meisel, Lee A

2008-01-01

298

Rhythmicity in Ethylene Production in Cotton Seedlings 1  

PubMed Central

Cotyledons of cotton (Gossypium hirsutum L.) seedlings grown under a photoperiod of 12 hour darkness and 12 hour light showed daily oscillations in ethylene evolution. The rate of ethylene evolution began to increase toward the end of the dark period and reached a maximum rate during the first third of the light period, then it declined and remained low until shortly before the end of the dark period. The oscillations in ethylene evolution occurred in young, mature, and old cotyledons (7 to 21 day old). These oscillations in ethylene evolution seemed to be endogenously controlled since they continued even when the photoperiod was inverted. Moreover, in continuous light the oscillations in ethylene evolution persisted, but with shorter intervals between the maximal points of ethylene evolution. In continuous darkness the oscillations in ethylene evolution disappeared. The conversion of [3,4-14C]methionine into [14C] ethylene followed the oscillations in ethylene evolution in the regular as well as the inverted photoperiod. On the other hand, the conversion of applied 1-aminocyclopropane-1-carboxylic acid into ethylene did not follow the oscillations in ethylene evolution, but was affected directly by the light conditions. Always, light decreased and darkness increased the conversion of applied 1-aminocyclopropane-1-carboxylic acid into ethylene. It is concluded that in the biosynthetic pathway of ethylene the conversion of 1-aminocyclopropane-1-carboxylic acid into ethylene is directly affected by light while an earlier step is controlled by an endogenous rhythm.

Rikin, Arnon; Chalutz, Edo; Anderson, James D.

1984-01-01

299

Effect of spaceflight on isoflavonoid accumulation in etiolated soybean seedlings  

NASA Technical Reports Server (NTRS)

In order to explore the potential impact of microgravity on flavonoid biosynthesis, we examined isoflavonoid levels in soybean (Glycine max) tissues generated under both spaceflight and clinorotation conditions. A 6-day Space Shuttle-based microgravity exposure resulted in enhanced accumulation of isoflavone glycosides (daidzin, 6"-O-malonyl-7-O-glucosyl daidzein, genistin, 6"-O-malonyl-7-O-glucosyl genistein) in hypocotyl and root tissues, but reduced levels in cotyledons (relative to 1g controls on Earth). Soybean seedlings grown on a horizontally rotating clinostat for 3, 4 and 5 days exhibited (relative to a vertical clinorotation control) an isoflavonoid accumulation pattern similar to the space-grown tissues. Elevated isoflavonoid levels attributable to the clinorotation treatment were transient, with the greatest increase observed in the three-day-treated tissues and smaller increases in the four- and five-day-treated tissues. Differences between stresses presented by spaceflight and clinorotation and the resulting biochemical adaptations are discussed, as is whether the increase in isoflavonoid concentrations were due to differential rates of development under the "gravity" treatments employed. Results suggest that spaceflight exposure does not impair isoflavonoid accumulation in developing soybean tissues and that isoflavonoids respond positively to microgravity as a biochemical strategy of adaptation.

Levine, L. H.; Levine, H. G.; Stryjewski, E. C.; Prima, V.; Piastuch, W. C.; Sager, J. S. (Principal Investigator)

2001-01-01

300

Investigations into peach seedling stunting caused by a replant soil.  

PubMed

Replant diseases often occur when pome and stone fruits are grown in soil that had previously been planted with the same or similar plant species. They typically lead to reductions in plant growth, crop yield and production duration. In this project, greenhouse assays were used to identify a peach orchard soil that caused replant disease symptoms. Biocidal treatments of this soil led to growth increases of Nemaguard peach seedlings. In addition, plants grown in as little as 1% of the replant soil exhibited reduced plant growth. These results suggest that the disease etiology has a biological component. Analysis of roots from plants exhibiting various levels of replant disease symptoms showed little difference in the amounts of PCR-amplified bacterial or fungal rRNA genes. However, analysis using a stramenopile-selective PCR assay showed that rRNA genes from this taxon were generally more abundant in plants with the smallest top weights. Nucleotide sequence analysis of these genes identified several phylotypes belonging to Bacillariophyta, Chrysophyceae, Eustigmatophyceae, Labyrinthulida, Oomycetes, Phaeophyceae and Synurophyceae. Sequence-selective quantitative PCR assays targeting four of the most abundant phylotypes showed that both diatoms (Sellaphora spp.) and an oomycete (Pythium ultimum) were negatively associated with plant top weights. PMID:19573200

Bent, Elizabeth; Loffredo, Angelo; Yang, Jiue-In; McKenry, Michael V; Becker, Jörn Ole; Borneman, James

2009-05-01

301

Proteome analysis of roots of wheat seedlings under aluminum stress.  

PubMed

The root apex is considered the first sites of aluminum (Al) toxicity and the reduction in root biomass leads to poor uptake of water and nutrients. Aluminum is considered the most limiting factor for plant productivity in acidic soils. Aluminum is a light metal that makes up 7 % of the earth's scab dissolving ionic forms. The inhibition of root growth is recognized as the primary effect of Al toxicity. Seeds of wheat cv. Keumkang were germinated on petridish for 5 days and then transferred hydroponic apparatus which was treated without or with 100 and 150 ?M AlCl3 for 5 days. The length of roots, shoots and fresh weight of wheat seedlings were decreased under aluminum stress. The concentration of K(+), Mg(2+) and Ca(2+) were decreased, whereas Al(3+) and P2O5 (-) concentration was increased under aluminum stress. Using confocal microscopy, the fluorescence intensity of aluminum increased with morin staining. A proteome analysis was performed to identify proteins, which are responsible to aluminum stress in wheat roots. Proteins were extracted from roots and separated by 2-DE. A total of 47 protein spots were changed under Al stress. Nineteen proteins were significantly increased such as sadenosylmethionine, oxalate oxidase, malate dehydrogenase, cysteine synthase, ascorbate peroxidase and/or, 28 protein spots were significantly decreased such as heat shock protein 70, O-methytransferase 4, enolase, and amylogenin. Our results highlight the importance and identification of stress and defense responsive proteins with morphological and physiological state under Al stress. PMID:24357239

Oh, Myeong Won; Roy, Swapan Kumar; Kamal, Abu Hena Mostofa; Cho, Kun; Cho, Seong-Woo; Park, Chul-Soo; Choi, Jong-Soon; Komatsu, Setsuko; Woo, Sun-Hee

2014-02-01

302

Clinorotation affects morphology and ethylene production in soybean seedlings  

NASA Technical Reports Server (NTRS)

The microgravity environment of spaceflight influences growth, morphology and metabolism in etiolated germinating soybean. To determine if clinorotation will similarly impact these processes, we conducted ground-based studies in conjunction with two space experiment opportunities. Soybean (Glycine max [L.] Merr.) seeds were planted within BRIC (Biological Research In Canister) canisters and grown for seven days at 20 degrees C under clinorotation (1 rpm) conditions or in a stationary upright mode. Gas samples were taken daily and plants were harvested after seven days for measurement of growth and morphology. Compared to the stationary upright controls, plants exposed to clinorotation exhibited increased root length (125% greater) and fresh weight (42% greater), whereas shoot length and fresh weight decreased by 33% and 16% respectively. Plants grown under clinorotation produced twice as much ethylene as the stationary controls. Seedlings treated with triiodo benzoic acid (TIBA), an auxin transport inhibitor, under clinorotation produced 50% less ethylene than the untreated control subjected to the same gravity treatment, whereas a treatment with 2,4-D increased ethylene by five-fold in the clinorotated plants. These data suggest that slow clinorotation influences biomass partitioning and ethylene production in etiolated soybean plants.

Hilaire, E.; Peterson, B. V.; Guikema, J. A.; Brown, C. S.; Sager, J. C. (Principal Investigator)

1996-01-01

303

Prosopis pubescens (screw bean mesquite) seedlings are hyperaccumulators of copper.  

PubMed

Due to health reasons, toxic metals must be removed from soils contaminated by mine tailings and smelter activities. The phytoremediation potential of Prosopis pubescens (screw bean mesquite) was examined by use of inductively-coupled plasma optical emission spectroscopy. Transmission electron microscopy was used to observe ultrastructural changes of parenchymal cells of leaves in the presence of copper. Elemental analysis was used to localize copper within leaves. A 600-ppm copper sulfate exposure to seedlings for 24 days resulted in 31,000 ppm copper in roots, 17,000 ppm in stems, 11,000 in cotyledons and 20 ppm in the true leaves. For a plant to be considered a hyperaccumulator, the plant must accumulate a leaf-to-root ratio <1. Screw bean mesquite exposed to copper had a leaf-to-root ratio of 0.355 when cotyledons were included. We showed that P. pubescens grown in soil is a hyperaccumulator of copper. We recommend that this plant should be field tested. PMID:23612918

Zappala, Marian N; Ellzey, Joanne T; Bader, Julia; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge

2013-08-01

304

Polyamines in rice seedlings under oxygen-deficit stress  

SciTech Connect

Incubation of 3-d-old seedlings of Oryza sativa L. cv Arborio under anaerobic conditions, leads to a large increase in the titer of free putrescine while aerobic incubation causes a slight decrease. After 2 days, the putrescine level is about 2.5 times greater without oxygen than in air. The rice coleoptile also accumulates a large amount of bound putrescine and, to a lesser extent, spermidine and spermine (mainly as acid-soluble conjugates). Accumulation of conjugates in the roots is severely inhibited by the anaerobic treatment. Feeding experiments with labeled amino acids showed that anoxia stimulates the release of {sup 14}CO{sub 2} from tissues fed with ({sup 14}C)arginine and that arginine is the precursor in putrescine biosynthesis. After 2 d of anoxia, the activity of arginine decarboxylase was 42% and 89% greater in coleoptile and root, respectively, than in the aerobic condition. The causes of the differences in polyamine metabolism in anoxic coleoptiles and roots are discussed.

Reggiani, R.; Hochkoeppler, A.; Bertani, A. (A.N.R., Milano (Italy))

1989-11-01

305

Rhizobacteria of cotton and their repression of seedling disease pathogens.  

PubMed

During the 1983 field season, the rhizobacteria (including organisms from rhizosphere soil and the root rhizoplane) of cotton plants at one location in Mississippi were inventoried at different plant growth stages. Isolates (1,000) were identified to the genus level and characterized for repression of Pythium ultimum and Rhizoctonia solani. Cotton seedlings were initially colonized by bacteria of many different genera, and populations quickly reached 10 CFU/g of root tissue. As the season progressed, the bacterial populations declined as root mass increased and the roots became more woodlike in consistency. Fluorescent pseudomonads were the most numerous gram-negative rhizobacterial isolates of those that were randomly collected and identified, and they provided the largest number of isolates with fungal repressive activity. Several other gram-negative bacterial genera were recovered throughout the growing season, and some gram-positive bacteria were also isolated routinely, but at lower numbers. There was no correlation between the proportion of rhizobacterial isolates that possessed fungal repressive activity and the plant growth stage from which the isolates were obtained. Approximately twice as many bacterial isolates demonstrated fungal repression in the agar assay compared with the inplanta assay, and isolates were found more frequently with fungal repressive activity against P. ultimum than against R. solai. PMID:16348043

Hagedorn, C; Gould, W D; Bardinelli, T R

1989-11-01

306

Rhizobacteria of Cotton and Their Repression of Seedling Disease Pathogens  

PubMed Central

During the 1983 field season, the rhizobacteria (including organisms from rhizosphere soil and the root rhizoplane) of cotton plants at one location in Mississippi were inventoried at different plant growth stages. Isolates (1,000) were identified to the genus level and characterized for repression of Pythium ultimum and Rhizoctonia solani. Cotton seedlings were initially colonized by bacteria of many different genera, and populations quickly reached 108 CFU/g of root tissue. As the season progressed, the bacterial populations declined as root mass increased and the roots became more woodlike in consistency. Fluorescent pseudomonads were the most numerous gram-negative rhizobacterial isolates of those that were randomly collected and identified, and they provided the largest number of isolates with fungal repressive activity. Several other gram-negative bacterial genera were recovered throughout the growing season, and some gram-positive bacteria were also isolated routinely, but at lower numbers. There was no correlation between the proportion of rhizobacterial isolates that possessed fungal repressive activity and the plant growth stage from which the isolates were obtained. Approximately twice as many bacterial isolates demonstrated fungal repression in the agar assay compared with the inplanta assay, and isolates were found more frequently with fungal repressive activity against P. ultimum than against R. solai.

Hagedorn, C.; Gould, W. D.; Bardinelli, T. R.

1989-01-01

307

Seedling Discrimination with Shape Features Derived from a Distance Transform  

PubMed Central

The aim of this research is an improvement of plant seedling recognition by two new approaches of shape feature generation based on plant silhouettes. Experiments show that the proposed feature sets possess value in plant recognition when compared with other feature sets. Both methods approximate a distance distribution of an object, either by resampling or by approximation of the distribution with a high degree Legendre polynomial. In the latter case, the polynomial coefficients constitute a feature set. The methods have been tested through a discrimination process where two similar plant species are to be distinguished into their respective classes. The used performance assessment is based on the classification accuracy of 4 different classifiers (a k-Nearest Neighbor, Naive-Bayes, Linear Support Vector Machine, Nonlinear Support Vector Machine). Another set of 21 well-known shape features described in the literature is used for comparison. The used data consisted of 139 samples of cornflower (Centaura cyanus L.) and 63 samples of nightshade (Solanum nigrum L.). The highest discrimination accuracy was achieved with the Legendre Polynomial feature set and amounted to 97.5%. This feature set consisted of 10 numerical values. Another feature set consisting of 21 common features achieved an accuracy of 92.5%. The results suggest that the Legendre Polynomial feature set can compete with or outperform the commonly used feature sets.

Giselsson, Thomas Mosgaard; Midtiby, Henrik Skov; J?rgensen, Rasmus Nyholm

2013-01-01

308

Landfill leachate affects metabolic responses of Zea mays L. seedlings.  

PubMed

With an increasing focus on phyto-remediation options for landfill leachate, it is important to understand the responses of plant systems to landfill leachate stress. It is especially important to study the tolerant mechanisms of plant systems. We investigated several physiological changes of Zea mays L. (maize) in response to landfill leachate. Specifically, we investigated growth, chlorophyll content, lipid peroxidation, protein oxidation and activities of antioxidant enzymes. The results indicate that landfill leachate affected the growth and chlorophyll level of maize seedlings. Furthermore, landfill leachate elevated the levels of lipid peroxidation and protein oxidation in leaf tissues in a time-dependent manner, accompanied by the changes in antioxidant status. The physiological responses varied as a function of leachate concentration, and the growth inhibition, chlorophyll content inhibition and oxidative stress occurred after the exposure of higher concentrations of leachate. Higher concentrations of landfill leachate contained higher levels of pollutants. Our results indicate that landfill leachate affected the metabolic responses of plant systems. The risk of pollution occurred mainly in samples of higher concentration. Therefore, the critical aspect of phyto-remediation for landfill leachate is controlling its concentration. In doing so, plant systems may be able to tolerate the environmental stress of landfill leachate. PMID:20149964

Sang, Nan; Han, Ming; Li, Guangke; Huang, Mingzhu

2010-05-01

309

Effect of osmo- and hydropriming of chickpea seeds on seedling growth and carbohydrate metabolism under water deficit stress  

Microsoft Academic Search

Seven-day-old seedlings obtained from seeds primed with mannitol (4%)and water showed three to four fold more growth with respect to root and shootlength in comparison with seedlings obtained from non-primed seeds. Seedlingswere grown under water deficit stress conditions created by 15% polyethyleneglycol (PEG) 6000 in the medium. Priming of chickpea seeds with NaCl and PEGwasnot effective in increasing seedling growth

Satvir Kaur; Anil K. Gupta; Narinder Kaur

2002-01-01

310

Tree proximity, soil pathways and common mycorrhizal networks: their influence on the utilization of redistributed water by understory seedlings.  

PubMed

Hydraulic redistribution (HR) is a process by which water moves through plant roots from moist to dry soils. An experiment was conducted to quantify the influence of common mycorrhizal networks (CMNs) and proximity to mature HR-source trees on the water relations of surrounding seedlings. Douglas-fir (Pseudotsuga menziesii var glauca (Mirb.) Franco) seedlings were planted at four distances (0.5, 1, 2.5, and 5 m) from six mature Douglas-fir trees, either directly into soil (soil plus CMN pathway) or inside 0.5 microm mesh bags (soil-only pathway). Deuterated water was used to irrigate soil beside mature trees in order to identify different HR water pathways to surrounding seedlings. This was followed by measurements of seedling deuterium enrichment, seedling water potential, soil water potential, gravimetric soil water content, and tree root density surrounding the seedlings. There was no significantly detectable difference in the quantity of HR water transferred to seedlings having access to soil and CMN pathways or soil-only pathways of water movement. Water from the irrigation plot contributed up to 1.4% of the water of Douglas-fir seedlings. Based on the assumption that the only pathway through which seedlings could access irrigation water was through the mature trees, we estimate that as much as 21.6% of the seedling water was supplied by the nearby tree. Seedling water potential was not significantly affected either by proximity to mature trees or pathway, suggesting HR may have compensated for increasing tree competitive effects with proximity. It is also possible that the lack of difference was due to a relatively moist summer. Our results suggest that residual mature trees are potentially important for hydraulic redistribution to regenerating seedlings in harvested dry interior Douglas-fir forests. PMID:17885766

Schoonmaker, Amanda L; Teste, François P; Simard, Suzanne W; Guy, Robert D

2007-12-01

311

Cowpea ribonuclease: properties and effect of NaCl-salinity on its activation during seed germination and seedling establishment  

Microsoft Academic Search

Pitiúba cowpea [Vigna unguiculata (L.) Walp] seeds were germinated in distilled water (control treatment) or in 100 mM NaCl solution (salt treatment), and\\u000a RNase was purified from different parts of the seedlings. Seedling growth was reduced by the NaCl treatment. RNase activity\\u000a was low in cotyledons of quiescent seeds, but the enzyme was activated during germination and seedling establishment. Salinity\\u000a reduced

Enéas Gomes-Filho; Carmen Rogélia Farias Machado Lima; José Hélio Costa; Ana Cláudia Marinho da Silva; Maria da Guia Silva Lima; Claudivan Feitosa de Lacerda; José Tarquinio Prisco

2008-01-01

312

Stress-related genes define essential steps in the response of maize seedlings to smoke-water  

Microsoft Academic Search

Smoke from burning vegetation is widely recognised as a germination cue for seed germination and recent reports suggest that\\u000a smoke treatments can improve seedling vigour also. We investigated the effect of smoke-water on seedling vigour and changes\\u000a of the global transcriptome in the early post-germination phase in maize. Application of smoke-water improved the germination\\u000a characteristics and seedling vigour. The transcriptional

Vilmos Soós; Endre Sebestyén; Angéla Juhász; János Pintér; Marnie E. Light; Johannes Van Staden; Ervin Balázs

2009-01-01

313

A Mutation in Arabidopsis SEEDLING PLASTID DEVELOPMENT1 Affects Plastid Differentiation in Embryo-Derived Tissues during Seedling Growth1[W][OA  

PubMed Central

Oilseed plants like Arabidopsis (Arabidopsis thaliana) develop green photosynthetically active embryos. Upon seed maturation, the embryonic chloroplasts degenerate into a highly reduced plastid type called the eoplast. Upon germination, eoplasts redifferentiate into chloroplasts and other plastid types. Here, we describe seedling plastid development1 (spd1), an Arabidopsis seedling albino mutant capable of producing normal green vegetative tissues. Mutant seedlings also display defects in etioplast and amyloplast development. Precocious germination of spd1 embryos showed that the albino seedling phenotype of spd1 was dependent on the passage of developing embryos through the degreening and dehydration stages of seed maturation, suggesting that SPD1 is critical during eoplast development or early stages of eoplast redifferentiation. The SPD1 gene was found to encode a protein containing a putative chloroplast-targeting sequence in its amino terminus and also domains common to P-loop ATPases. Chloroplast localization of the SPD1 protein was confirmed by targeting assays in vivo and in vitro. Although the exact function of SPD1 remains to be defined, our findings reveal aspects of plastid development unique to embryo-derived cells.

Ruppel, Nicholas J.; Logsdon, Charles A.; Whippo, Craig W.; Inoue, Kentaro; Hangarter, Roger P.

2011-01-01

314

Seedling Responses to Water Pulses in Shrubs with Contrasting Histories of Grassland Encroachment  

PubMed Central

Woody plant encroachment into grasslands has occurred worldwide, but it is unclear why some tree and shrub species have been markedly more successful than others. For example, Prosopis velutina has proliferated in many grasslands of the Sonoran Desert in North America over the past century, while other shrub species with similar growth form and life history, such as Acacia greggii, have not. We conducted a glasshouse experiment to assess whether differences in early seedling development could help explain why one species and not the other came to dominate many Sonoran Desert grasslands. We established eight watering treatments mimicking a range of natural precipitation patterns and harvested seedlings 16 or 17 days after germination. A. greggii had nearly 7 times more seed mass than P. velutina, but P. velutina emerged earlier (by 3.0±0.3 d) and grew faster (by 8.7±0.5 mg d?1). Shoot mass at harvest was higher in A. greggii (99±6 mg seedling?1) than in P. velutina (74±2 mg seedling?1), but there was no significant difference in root mass (54±3 and 49±2 mg seedling?1, respectively). Taproot elongation was differentially sensitive to water supply: under the highest initial watering pulse, taproots were 52±19 mm longer in P. velutina than in A. greggii. Enhanced taproot elongation under favorable rainfall conditions could give nascent P. velutina seedlings growth and survivorship advantages by helping reduce competition with grasses and maintain contact with soil water during drought. Conversely, A. greggii's greater investment in mass per seed appeared to provide little return in early seedling growth. We suggest that such differences in recruitment traits and their sensitivities to environmental conditions may help explain ecological differences between species that are highly similar as adults and help identify pivotal drivers of shrub encroachment into grasslands.

Woods, Steven R.; Archer, Steven R.; Schwinning, Susan

2014-01-01

315

Ability of ellagic acid to alleviate osmotic stress on chickpea seedlings.  

PubMed

Seed germination and growth of seedlings are critical phases of plant life that are adversely affected by various environmental cues. Water availability is one of the main factors that limit the productivity of many crops. This study was conducted to assess the changes in the sensitivity of chickpea seedlings to osmotic stress by prior treatment of chickpea seeds with a low concentration (50 ppm) of ellagic acid. Ellagic acid was isolated and purified from Padina boryana Thivy by chromatographic techniques. After ellagic acid treatment, seeds were germinated for 10 days under different osmotic potentials (0, -0.2, -0.4, -0.6 and -0.8 MPa) of polyethylene glycol (PEG) solutions. Ellagic acid treatment accelerated the germination and seedling growth of chickpea under osmotic stress conditions. Consistent with the accelerated growth, ellagic acid-treated seedlings also showed a significant increase in the total antioxidant capacity (FRAP) as well as an increase in the compatible solutes (proline and glycine betaine) content. Additionally, treated seedlings revealed lower lipid peroxidation levels (MDA), electrolyte leakage (EL) and H2O2. Flavonoid and reduced glutathione (GSH) content, and the activity of antioxidant enzymes [catalase (CAT), peroxidase (POX), superoxide dismutase (SOD), glutathione reductase (GR)] and enzymes of the shikimic acid pathway [phenylalanine ammonia lyase (PAL) and chalcone synthase (CHS)] all showed a remarkable increase with ellagic acid pretreatment compared to untreated seedlings especially under mild osmotic stress values (-0.2 and -0.4 MPa). These results suggested that treatment with ellagic acid could confer an increased tolerance of chickpea seedlings to osmotic stress, through reducing levels of H2O2 and increasing antioxidant capacity. PMID:23938205

Abu El-Soud, Walid; Hegab, Momtaz Mohamed; AbdElgawad, Hamada; Zinta, Gaurav; Asard, Han

2013-10-01

316

Recruitment dynamics in a rainforest seedling community: context-independent impact of a keystone consumer.  

PubMed

The influence of keystone consumers on community structure is frequently context-dependent; the same species plays a central organising role in some situations, but not others. On Christmas Island, in the Indian Ocean, a single species of omnivorous land crab, Gecarcoidea natalis, dominates the forest floor across intact rainforest. We hypothesised that this consumer plays a key role in regulating seedling recruitment and in controlling litter dynamics on the island, independent of the type of vegetation in which it occurred. To test this hypothesis, we conducted crab exclusion experiments in two forest types on the island and followed the dynamics of seedling recruitment and litter processing for six years. To determine if these effects were likely to be general across the island, we compared land crab densities and seedling abundance and diversity at ten sites across island rainforest. Surveys across island rainforest showed that seedlings of species susceptible to predation by land crabs are consistently rare. Abundance and diversity of these species were negatively correlated to red crab abundance. Although red land crabs may be important determinants of seedling recruitment to the overstorey, differences in overstorey and seedling composition at the sites suggests that recruitment of vulnerable trees still occurs at a temporal scale exceeding that of this study. These "windows" of recruitment may be related to infrequent events that reduce the effects of land crabs. Our results suggest that unlike the context dependence of most keystone consumers in continental systems, a single consumer, the red land crab, consistently controls the dynamics of seedling recruitment across this island rainforest. PMID:18320231

Green, Peter T; O'Dowd, Dennis J; Lake, P S

2008-05-01

317

Effects of methyl jasmonate on accumulation of flavonoids in seedlings of common buckwheat (Fagopyrum esculentum Moench).  

PubMed

The jasmonates, which include jasmonic acid and its methyl ester (MJ), play a central role in regulating the biosynthesis of many secondary metabolites, including flavonoids, and also are signaling molecules in environmental stresses. Synthesis of anthocyanins pigments is a final part of flavonoids pathway route. Accumulation of the pigments in young seedlings is stimulated by various environmental stresses, such as high-intensity light, wounding, pathogen attack, drought, sugar and nutrient deficiency. The anthocyanins take part in defense system against excess of light and UV-B light, and therefore it is probably main reason why young plant tissues accumulate enlarged levels of the pigments. The effects of exogenously applied MJ on level of anthocyanins, glycosides of apigenin, luteolin, quercetin and proanthocyanidins in seedlings of common buckwheat (Fagopyrum esculentum Moench) were studied. MJ decreased contents of all the found cyanidin glycosides and its aglycone in hypocotyls of buckwheat seedlings. However contents of particular anthocyanins in cotyledons of buckwheat seedlings treated with the plant hormone were not significantly different from the control. Applied doses of MJ did not affect levels of quercetin, apigenin and luteolin glycosides in the analyzed parts of buckwheat seedlings: cotyledons and hypocotyls. On the other hand, treatment of buckwheat seedlings with MJ clearly stimulated of proanthocyanidins biosynthesis in hypocotyls. We suggest that methyl jasmonate induces in hypocotyls of buckwheat seedlings the leucocyanidin reductase or anthocyanidin reductase, possible enzymes in proanthocyanidins synthesis, and/or inhibits anthocyanidin synthase, which transforms leucocyanidin into cyanidin. According to our knowledge this is the first report regarding the effect of methyl jasmonate on enhancing the accumulation of proanthocyanidins in cultivated plants. PMID:21840829

Horbowicz, M; Wiczkowski, W; Koczkodaj, Danuta; Saniewski, M

2011-09-01

318

Basal Transcription Factor 3 Plays an Important Role in Seed Germination and Seedling Growth of Rice  

PubMed Central

BTF3 has been recognized to be involved in plant growth and development. But its function remains mostly unknown during seed germination and seedling stage. Here, we have analyzed OsBTF3-related sequences in Oryza sativa L. subspecies, japonica, which resembles with the conserved domain of a nascent polypeptide associated complex (NAC) with different homologs of OsBTF3 and human BTF3. Inhibition of Osj10gBTF3 has led to considerable morphological changes during seed germination and seedling growth. Germination percentage was not influenced by the application of GA3, ABA, and NaCl but all concentrations caused wild-type (WT) seeds to germinate more rapidly than the RNAi (Osj10gBTF3Ri) transgenic lines. Seedling inhibition was more severe in the Osj10gBTF3Ri seedlings compared with their WT especially when treated with 100 or 200??M GA3; 50% reduction in shoots was observed in Osj10gBTF3Ri seedlings. The expression of Osj3g1BTF3, Osj3g2BTF3 and Osj10gBTF3 was primarily constitutive and generally modulated by NaCl, ABA, and GA3 stresses in both Osj10gBTF3Ri lines and WT at the early seedling stage, suggesting that Osj3g1BTF3 and Osj10gBTF3 are much similar but different from Osj3g2BTF3 in biological function. These results show that OsBTF3 plays an important role in seed germination and seedling growth gives a new perception demonstrating that more multifaceted regulatory functions are linked with BTF3 in plants.

Wang, Wenyi; Xu, Mengyun; Wang, Ya

2014-01-01

319

Root growth, secondary root formation and root gravitropism in carotenoid-deficient seedlings of Zea mays L  

NASA Technical Reports Server (NTRS)

The effect of ABA on root growth, secondary-root formation and root gravitropism in seedlings of Zea mays was investigated by using Fluridone-treated seedlings and a viviparous mutant, both of which lack carotenoids and ABA. Primary roots of seedlings grown in the presence of Fluridone grew significantly slower than those of control (i.e. untreated) roots. Elongation of Fluridone-treated roots was inhibited significantly by the exogenous application of 1 mM ABA. Exogenous application of 1 micromole and 1 nmole ABA had either no effect or only a slight stimulatory effect on root elongation, depending on the method of application. The absence of ABA in Fluridone-treated plants was not an important factor in secondary-root formation in seedlings less than 9-10 d old. However, ABA may suppress secondary-root formation in older seedlings, since 11-d-old control seedlings had significantly fewer secondary roots than Fluridone-treated seedlings. Roots of Fluridone-treated and control seedlings were graviresponsive. Similar data were obtained for vp-9 mutants of Z. mays, which are phenotypically identical to Fluridone-treated seedlings. These results indicate that ABA is necessary for neither secondary-root formation nor for positive gravitropism by primary roots.

Ng, Y. K.; Moore, R.

1985-01-01

320

Endoreduplication in the germinating embryo and young seedling is related to the type of seedling establishment but is not coupled with superoxide radical accumulation.  

PubMed

During germination, the embryo axis elongates and the radicle emerges through the surrounding structures of the seed. However, this elongation is not even along the axis, and it has been suggested that the region responsible for radicle protrusion is related to the type of subsequent seedling establishment. Eleven epigeal- and five hypogeal-type species were selected to study endoreduplication, a process coupled with cell elongation, in the radicle, hypocotyl-radicle transition zone, hypocotyl, and cotyledons of dry and germinating seeds, and in seedlings after radicle protrusion. Flow cytometry was used to establish the proportions of nuclei with different DNA contents, the mean C-value, and the (?>2C)/2C ratio. Additionally, a nitroblue tetrazolium chloride test was applied to the embryos/seedlings in the dry state and during and after germination to localize superoxide radical (O2 (•-)) accumulation, which has been suggested to play a role in cell elongation. Endoreduplication intensity varied in different species, in the embryo/seedling regions, and with the type of seedling establishment. In most of the cases, it was highest in the transition zone of epigeal species and in the hypocotyl in hypogeal species. O2 (•-) was invariably produced during germination in the radicle, and additionally in the transition zone at the time of radicle protrusion; thus, it was not coupled with endoreduplication, and most probably played a role in defence against biotic and abiotic environmental stresses. These results provide information to aid in the selection of the most suitable plant material for molecular research on germination and for monitoring seed priming. PMID:24863437

Rewers, Monika; Sliwinska, Elwira

2014-08-01

321

Proteomic analysis of rice seedlings during cold stress.  

PubMed

Low temperature is one of the important environmental changes that affect plant growth and agricultural production. To investigate the responses of rice to cold stress, changes in protein expression were analyzed using a proteomic approach. Two-week-old rice seedlings were exposed to 5 degrees C for 48 h, then total crude proteins were extracted from leaf blades, leaf sheaths and roots, separated by 2-DE and stained with CBB. Of the 250-400 protein spots from each organ, 39 proteins changed in abundance after cold stress, with 19 proteins increasing, and 20 proteins decreasing. In leaf blades, it was difficult to detect the changes in stress-responsive proteins due to the presence of an abundant protein, ribulose bisphosphate carboxylase/oxygenase large subunit (RuBisCO LSU), which accounted for about 50% of the total proteins. To overcome this problem, an antibody-affinity column was prepared to trap RuBisCO LSU, and the remaining proteins in the flow through from the column were subsequently separated using 2-DE. As a result, slight changes in stress responsive proteins were clearly displayed, and four proteins were newly detected after cold stress. From identified proteins, it was concluded that proteins related to energy metabolism were up-regulated, and defense-related proteins were down-regulated in leaf blades, by cold stress. These results suggest that energy production is activated in the chilling environment; furthermore, stress-related proteins are rapidly up-regulated, while defense-related proteins disappear, under long-term cold stress. PMID:17380535

Hashimoto, Makoto; Komatsu, Setsuko

2007-04-01

322

Sensitivity of Mediterranean woody seedlings to copper, nickel and zinc.  

PubMed

The restoration of heavy metal contaminated areas requires information on the response of native plant species to these contaminants. The sensitivity of most Mediterranean woody species to heavy metals has not been established, and little is known about phytotoxic thresholds and environmental risks. We have evaluated the response of four plant species commonly used in ecological restoration, Pinus halepensis, Pistacia lentiscus, Juniperus oxycedrus, and Rhamnus alaternus, grown in nutrient solutions containing a range of copper, nickel and zinc concentrations. Seedlings of these species were exposed to 0.048, 1 and 4 microM of Cu; 0, 25 and 50 microM of Ni; and 0.073, 25 and 100 microM of Zn in a hydroponic silica sand culture for 12 weeks. For all four species, the heavy metal concentration increased in plants as the solution concentration increased and was always higher in roots than in shoots. Pinus halepensis and P. lentiscus showed a higher capacity to accumulate metals in roots than J. oxycedrus and R. alaternus, while the allocation to shoots was considerably higher in the latter two. Intermediate heavy-metal doses enhanced biomass accumulation, whereas the highest doses resulted in reductions in biomass. Decreases in shoot biomass occurred at internal concentrations ranging from 25 to 128 microg g-1 of Zn, and 1.7 to 4.1 microg g( -1) of Cu. Nickel phytoxicity could not be established within the range of doses used. Rhamnus alaternus and J. oxycedrus showed higher sensitivity to Cu and Zn than P. halepensis and, especially, P. lentiscus. Contrasted responses to heavy metals must be taken into account when using Mediterranean woody species for the restoration of heavy metal contaminated sites. PMID:16870229

Fuentes, David; Disante, Karen B; Valdecantos, Alejandro; Cortina, Jordi; Vallejo, V Ramón

2007-01-01

323

Low root reserve accumulation during drought may lead to winter mortality in poplar seedlings.  

PubMed

Climate models suggest that more frequent drought events of greater severity and length, associated with climate change, can be expected in the coming decades. Although drought-induced tree mortality has been recognized as an important factor modulating forest demography at the global scale, the mechanisms underlying drought-induced tree mortality remain contentious. Above- and below-ground growth, gas exchange, water relations and carbon reserve accumulation dynamics at the organ and whole-plant scale were quantified in Populus tremuloides and P. balsamifera seedlings in response to severe drought. Seedlings were maintained in drought conditions over one growing and one dormant winter season. Our experiment presents a detailed description of the effect of severe drought on growth and physiological variables, leading to seedling mortality after an extended period of drought and dormancy. After re-watering following the dormant period, drought-exposed seedlings did not re-flush, showing that the root system had died off. The results of this study suggest a complex series of physiological feedbacks between the measured variables in both Populus species. Further, they reveal that reduced reserve accumulation in the root system during drought decreases the conversion of starch to soluble sugars in roots, which may contribute to the root death of drought-exposed seedlings during the dormant season by compromising the frost tolerance of the root system. PMID:23347066

Galvez, David A; Landhäusser, S M; Tyree, M T

2013-04-01

324

Colonization of tomato seedlings by bioluminescent Clavibacter michiganensis subsp. michiganensis under different humidity regimes.  

PubMed

Tomato bacterial canker, caused by Clavibacter michiganensis subsp. michiganensis, is transmitted by infected or infested seed and mechanically from plant to plant. Wounds occurring during seedling production and crop maintenance facilitate the dissemination of the pathogen. However, the effects of environmental factors on C. michiganensis subsp. michiganensis translocation and growth as an endophyte have not been fully elucidated. A virulent, stable, constitutively bioluminescent C. michiganensis subsp. michiganensis strain BL-Cmm 17 coupled with an in vivo imaging system allowed visualization of the C. michiganensis subsp. michiganensis colonization process in tomato seedlings in real time. The dynamics of bacterial infection in seedlings through wounds were compared under low (45%) and high (83%) relative humidity. Bacteria multiplied rapidly in cotyledon petioles remaining after clip inoculation and moved in the stem toward both root and shoot. Luminescent signals were also observed in tomato seedling roots over time, and root development was reduced in inoculated plants maintained under both humidity regimes. Wilting was more severe in seedlings under high-humidity regimes. A strong positive correlation between light intensity and bacterial population in planta suggests that bioluminescent C. michiganensis subsp. michiganensis strains will be useful in evaluating the efficacy of bactericides and host resistance. PMID:21936661

Xu, Xiulan; Rajashekara, Gireesh; Paul, Pierce A; Miller, Sally A

2012-02-01

325

Androsterone-induced molecular and physiological changes in maize seedlings in response to chilling stress.  

PubMed

The aim of study was to elucidate the influence of foliar sprays of androsterone in alleviating detrimental effects of chilling stress in maize seedlings. Eleven-days-old maize seedlings were treated with 10(-9) mol L(-1) androsterone and then transferred to a chamber with temperature of 10/7 °C (day/night) for 3 days. The stress injury was measured in terms of increase in electrolyte leakage, superoxide production and hydrogen peroxide level, and decrease in chlorophyll content. Androsterone application mitigated significantly the chilling-induced stress injury. Under chilling stress, the oxidative damage which was measured as malondialdehyde content was lesser in androsterone-applied seedlings that were associated with greater activities of superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (POX), ascorbate peroxidase (APX) and glutathione reductase (GR). Moreover, SOD, POX and APX isozymes exhibited a strong correlation with changes in their activities. Androsterone application enhanced the level of antioxidant compounds like ascorbic acid, glutathione, proline and carotenoid as well as activities of antioxidant enzymes. Similarly, while androsterone treatment increased total antioxidant status, it reduced total oxidant status relative to chilling-stressed seedlings alone. Soluble protein profile was significantly changed by only chilling stress and chilling stress plus androsterone treatment, as well. According to these findings, it is possible to say that androsterone could be used to alleviate the damaging effects of chilling stress by improving antioxidative system in maize seedlings. This is the first study elucidating the effects of androsterone on resistance to chilling stress of plants. PMID:22634365

Erdal, Serkan

2012-08-01

326

[Alleviation effects of LaCl3 on photosynthetic characteristics of cucumber seedlings under nitrate stress].  

PubMed

By the method of hydroponic culture, this paper studied the alleviation effects of LaCl3 on the photosynthetic characteristics of cucumber seedlings under nitrate (140 mmol NO3(-) x L(-1)) stress, with the related mechanisms discussed. Under nitrate stress, the seedlings leaf chlorophyll and carotenoids contents decreased significantly, and the leaf Mg2+-ATPase, Ca2+-ATPase activities also decreased. On the 7th day of nitrate stress, the decrease of seedlings photosynthetic rate was mainly due to stomatal limitation; but on the 12th day of nitrate stress, the decrease was mainly due to no-stomatal limitation. Supplement with LaCl3 could make the cucumber seedlings keep relatively higher leaf Mg2+-ATPase and Ca2+-ATPase activities and chlorophyll and carotenoids contents, and applying 20 micromol x L(-1) of LaCl3 could increase the carotenoids content significantly. LaCl3 could also improve the leaf gas exchange, and alleviate the decrease of leaf Fv/Fm, PhiPSII, AQY, CE, and qp under nitrate stress, which helped the leaves making good use of light energy and maintaining higher CO2 assimilation capacity. An additional 20 micromol x L(-1) of LaCl3 could alleviate the nitrate stress on the photosynthesis of cucumber seedlings efficiently, but an additional 200 micromol x L(-1) of LaCl3 only had the alleviation effect at the initial period of nitrate stress. Our results could benefit to the improvement of greenhouse soil. PMID:20136001

Gao, Qing-Hai; Wu, Yan; Wang, Xiu-Feng; Lu, Xiao-Min; Shi, Qing-Hua

2009-11-01

327

Optimizing the calcium content of a copolymer acrylamide gel matrix for dark-grown seedlings  

NASA Technical Reports Server (NTRS)

A copolymer acrylamide acrylate gel was investigated as the sole root matrix for dark-grown seedlings of soybean (Glycine max Merr. 'Century 84'). Increasing Ca2+ in the hydrating solution of the hydrogel from 1 to 10 mM decreased its water-holding capacity from 97 to 46 mL g-1, yet water potential of the medium remained high, sufficient for normal plant growth at all Ca2+ concentrations tested. Elongation rate of dark-grown soybean seedlings over a 54-hour period was 0.9, 1.5, and 1.8 mm h-1 with 1.0, 2.5, or 5.0 mM Ca2+, respectively, but did not increase with further increases in Ca2+ concentration. Further study revealed that Na+ was released from the hydrogel medium and was taken up by the seedlings as Ca2+ increased in the medium. In dry hypocotyl tissue, sodium content correlated negatively with calcium content. Despite the presence of Na+ in the hydrogel, seedling growth was normal when adequate Ca2+ was added in the hydrating solution. Acrylamide hydrogels hold good potential as a sole growth matrix for short-term experiments with dark-grown seedlings without irrigation.

Myers, P. N.; Mitchell, C. A.

1998-01-01

328

The gluconeogenic enzyme phosphoenolpyruvate carboxykinase in Arabidopsis is essential for seedling establishment.  

PubMed

Phosphoenolpyruvate carboxykinase (PEPCK) catalyzes the conversion of oxaloacetate to phosphoenolpyruvate in the gluconeogenic production of sugars from storage oil in germinating oilseeds. Here, we present the results of analysis on PEPCK antisense Arabidopsis plants with a range of enzyme activities from 20% to 80% of wild-type levels. There is a direct correlation between enzyme activity and seedling establishment during early post-germinative growth, thus demonstrating the absolute requirement of PEPCK and gluconeogenesis in this process. Soluble sugar levels in the 35S-PCK1 antisense seedlings are reduced and seedling establishment can be rescued with an exogenous supply of sucrose. We observed an increase in the respiration of acetyl coenzyme A units released from fatty acid beta-oxidation and a corresponding decrease in the production of sugars with decreasing enzyme activity in 2-d-old antisense seedlings. The 35S-PCK1 antisense lines have a more extreme phenotype when compared with Arabidopsis mutants disrupted in the glyoxylate cycle. We conclude that the 35S-PCK1 antisense seedlings are compromised in the ability to use both storage lipid and storage protein through gluconeogenesis to produce soluble sugars. PMID:12692343

Rylott, Elizabeth L; Gilday, Alison D; Graham, Ian A

2003-04-01

329

Light Intensity Alters the Extent of Arsenic Toxicity in Helianthus annuus L. Seedlings.  

PubMed

The present study is aimed at assessing the extent of arsenic (As) toxicity under three different light intensities-optimum (400 ?mole photon m(-2) s(-1)), sub-optimum (225 ?mole photon m(-2) s(-1)), and low (75 ?mole photon m(-2) s(-1))-exposed to Helianthus annuus L. var. DRSF-113 seedlings by examining various physiological and biochemical parameters. Irrespective of the light intensities under which H. annuus L. seedlings were grown, there was an As dose (low, i.e., 6 mg kg(-1) soil, As1; and high, i.e., 12 mg kg(-1) soil, As2)-dependent decrease in all the growth parameters, viz., fresh mass, shoot length, and root length. Optimum light-grown seedlings exhibited better growth performance than the sub-optimum and low light-grown seedlings; however, low light-grown plants had maximum root and shoot lengths. Accumulation of As in the plant tissues depended upon its concentration used, proximity of the plant tissue, and intensity of the light. Greater intensity of light allowed greater assimilation of photosynthates accompanied by more uptake of nutrients along with As from the medium. The levels of chlorophyll a, b, and carotenoids declined with increasing concentrations of As. Seedlings acquired maximum Chl a and b under optimum light which were more compatible to face As1 and As2 doses of As, also evident from the overall status of enzymatic (SOD, POD, CAT, and GST) and non-enzymatic antioxidant (Pro). PMID:24699829

Yadav, Geeta; Srivastava, Prabhat Kumar; Singh, Vijay Pratap; Prasad, Sheo Mohan

2014-06-01

330

Hydrogen peroxide acts upstream of nitric oxide in the heat shock pathway in Arabidopsis seedlings.  

PubMed

We previously reported that nitric oxide (NO) functions as a signal in thermotolerance. To illustrate its relationship with hydrogen peroxide (H?O?) in the tolerance of Arabidopsis (Arabidopsis thaliana) to heat shock (HS), we investigated the effects of heat on Arabidopsis seedlings of the following types: the wild type; three NADPH oxidase-defective mutants that exhibit reduced endogenous H?O? levels (atrbohB, atrbohD, and atrbohB/D); and a mutant that is resistant to inhibition by fosmidomycin (noa1, for nitric oxide-associated protein1). After HS, the NO levels in atrbohB, atrbohD, and atrbohB/D seedlings were lower than that in wild-type seedlings. Treatment of the seedlings with sodium nitroprusside or S-nitroso-N-acetylpenicillamine partially rescued their heat sensitivity, suggesting that NO is involved in H?O? signaling as a downstream factor. This point was verified by phenotypic analyses and thermotolerance testing of transgenic seedlings that overexpressed Nitrate reductase2 and NOA1, respectively, in an atrbohB/D background. Electrophoretic mobility shift assays, western blotting, and real-time reverse transcription-polymerase chain reaction demonstrated that NO stimulated the DNA-binding activity of HS factors and the accumulation of HS proteins through H?O?. These data indicate that H?O? acts upstream of NO in thermotolerance, which requires increased HS factor DNA-binding activity and HS protein accumulation. PMID:24510762

Wang, Lei; Guo, Yunjing; Jia, Lixiu; Chu, Hongye; Zhou, Shuo; Chen, Kunming; Wu, Dan; Zhao, Liqun

2014-04-01

331

Carbon and nitrogen gain during the growth of orchid seedlings in nature.  

PubMed

For germination and establishment, orchids depend on carbon (C) and nutrients supplied by mycorrhizal fungi. As adults, the majority of orchids then appear to become autotrophic. To compare the proportional C and nitrogen (N) gain from fungi in mycoheterotrophic seedlings and in adults, here we examined in the field C and N stable isotope compositions in seedlings and adults of orchids associated with ectomycorrhizal and saprotrophic fungi. Using a new highly sensitive approach, we measured the isotope compositions of seedlings and adults of four orchid species belonging to different functional groups: fully and partially mycoheterotrophic orchids associated with narrow or broad sets of ectomycorrhizal fungi, and two adult putatively autotrophic orchids associated exclusively with saprotrophic fungi. Seedlings of orchids associated with ectomycorrhizal fungi were enriched in (13) C and (15) N similarly to fully mycoheterotrophic adults. Seedlings of saprotroph-associated orchids were also enriched in (13) C and (15) N, but unexpectedly their enrichment was significantly lower, making them hardly distinguishable from their respective adult stages and neighbouring autotrophic plants. We conclude that partial mycoheterotrophy among saprotroph-associated orchids cannot be identified unequivocally based on C and N isotope compositions alone. Thus, partial mycoheterotrophy may be much more widely distributed among orchids than hitherto assumed. PMID:24444001

Stöckel, Marcus; T?šitelová, Tamara; Jersáková, Jana; Bidartondo, Martin I; Gebauer, Gerhard

2014-04-01

332

Physiological aspects underlying the improved outplanting performance of Pinus pinaster Ait. seedlings associated with ectomycorrhizal inoculation.  

PubMed

Mycorrhizal inoculation of conifer roots is a key strategy to optimize establishment and performance of forest tree species under both natural and cultivated conditions and also to mitigate transplantation shock. However, despite being a common practice, inoculation in outdoor nursery conditions has been poorly studied. Here, we have evaluated effectiveness of four fungal species (Lactarius deliciosus, Lactarius quieticolor, Pisolithus arhizus, and Suillus luteus) in the production of mycorrhizal Pinus pinaster seedlings in an outdoor commercial nursery and their ability to improve seedling physiology and field performance. All inoculated seedlings showed a significant increase in growth at the end of the nursery stage and these differences remained after 3 years of growth in the field. Differences observed in the content of malondialdehyde, total chlorophyll, carotenoids, anthocyanins, and phenolic compounds from needles of mycorrhizal and control seedlings may reflect a different sensitivity to photo-oxidative damage. We conclude that ectomycorrhizal inoculation improves adaptability to changeable growing conditions of an outdoor nursery and produces a higher quality nursery stock, thereby enhancing seedling performance after planting. PMID:23674120

Sanchez-Zabala, Joseba; Majada, Juan; Martín-Rodrigues, Noemí; Gonzalez-Murua, Carmen; Ortega, Unai; Alonso-Grańa, Manuel; Arana, Orats; Duńabeitia, Miren K

2013-11-01

333

Physio-anatomic aspects on the initial growth of Guazuma ulmifolia Lam. seedlings.  

PubMed

This paper aimed to evaluate the initial growth of "mutambo" seedlings in different conditions of light intensity and treatments with gibberellic acid (GA). The seedlings were kept under full sun and 50% of shading. Sixty days after the emergence, seedlings were sprayed with: 1) 100 mg L(-1) GA(3); 2) 200 mg L(-1) GA(3); 3) control. At the end of the appraisals, seedlings height under 50% of shading was compared to the height that were growing under full sun with 200 mg L(-1) GA. Stem diameter was lower under shading. Leaf area did not vary among the treatments, but the root system growth was higher under full sun and did not vary among GA levels. The number of stomata, trichomes and epidermal cells on adaxial and abaxial sides was higher under full sun. Total dry masses of leaf and root were highe runder full sun and with 200 mg L(-1) GA application. "Mutambo" seedlings presented a higher initial growth under full sun, although with a lower height, diameter, and lenght of the largest root and total dry masses of leaf and root were higher. A concentration with 200 mg L(-1) promoted a higher growth. PMID:21670888

Scalon, Silvana P Q; Pereira, Heloisa H G; Glaeser, Daniele F; Silva, Jocemar J; Betoni, Roseli; Mussury, Rosilda M

2011-06-01

334

Expression of stress-related genes in zebrawood (Astronium fraxinifolium, Anacardiaceae) seedlings following germination in microgravity.  

PubMed

Seeds of a tropical tree species from Brazil, Astronium fraxinifolium, or zebrawood, were germinated, for the first time in microgravity, aboard the International Space Station for nine days. Following three days of subsequent growth under normal terrestrial gravitational conditions, greater root length and numbers of secondary roots was observed in the microgravity-treated seedlings compared to terrestrially germinated controls. Suppression subtractive hybridization of cDNA and EST analysis were used to detect differential gene expression in the microgravity-treated seedlings in comparison to those initially grown in normal gravity (forward subtraction). Despite their return to, and growth in normal gravity, the subtracted library derived from microgravity-treated seedlings was enriched in known microgravity stress-related ESTs, corresponding to large and small heat shock proteins, 14-3-3-like protein, polyubiquitin, and proteins involved in glutathione metabolism. In contrast, the reverse-subtracted library contained a comparatively greater variety of general metabolism-related ESTs, but was also enriched for peroxidase, possibly indicating the suppression of this protein in the microgravity-treated seedlings. Following continued growth for 30 days, higher concentrations of total chlorophyll were detected in the microgravity-exposed seedlings. PMID:24688295

Inglis, Peter W; Ciampi, Ana Y; Salomăo, Antonieta N; Costa, Tânia da S A; Azevedo, Vânia C R

2014-03-01

335

Expression of stress-related genes in zebrawood (Astronium fraxinifolium, Anacardiaceae) seedlings following germination in microgravity  

PubMed Central

Seeds of a tropical tree species from Brazil, Astronium fraxinifolium, or zebrawood, were germinated, for the first time in microgravity, aboard the International Space Station for nine days. Following three days of subsequent growth under normal terrestrial gravitational conditions, greater root length and numbers of secondary roots was observed in the microgravity-treated seedlings compared to terrestrially germinated controls. Suppression subtractive hybridization of cDNA and EST analysis were used to detect differential gene expression in the microgravity-treated seedlings in comparison to those initially grown in normal gravity (forward subtraction). Despite their return to, and growth in normal gravity, the subtracted library derived from microgravity-treated seedlings was enriched in known microgravity stress-related ESTs, corresponding to large and small heat shock proteins, 14-3-3-like protein, polyubiquitin, and proteins involved in glutathione metabolism. In contrast, the reverse-subtracted library contained a comparatively greater variety of general metabolism-related ESTs, but was also enriched for peroxidase, possibly indicating the suppression of this protein in the microgravity-treated seedlings. Following continued growth for 30 days, higher concentrations of total chlorophyll were detected in the microgravity-exposed seedlings.

Inglis, Peter W.; Ciampi, Ana Y.; Salomao, Antonieta N.; Costa, Tania da S.A.; Azevedo, Vania C.R.

2014-01-01

336

Morpho-anatomical changes and photosynthetic metabolism of Stenocereus beneckei seedlings under soil water deficit.  

PubMed

Characteristics developed by Cactaceae for adaptation to climates where water is limited include crassulacean acid metabolism (CAM), a thick cuticle, and spines and trichomes that intercept a proportion of solar radiation. A few studies consider morpho-anatomical and physiological characteristics of Cactaceae seedlings, which may help understand their establishment, growth, and eventual reproduction. In this study, photosynthetic metabolism (titratable protons) and morpho-anatomical features of Stenocereus beneckei seedlings were examined under limiting water conditions. Soil moisture treatments consisted of -0.03, -0.5, -1.5, and -3.0 MPa, and seedling samples were taken at 3 h intervals on one day at 7 and 9 months of age with three replicates per treatment. The results show irregular fluctuations in acidity concentrations during the first 6 and 7 months of age; at 9 months, an increase in titratable proton values was observed during the night, and it seems that soil moisture does not determine CAM expression. Seedlings from smaller seeds are less tolerant to water stress, they had poor growth in all treatments, and at -3.0 MPa after 3 months of drought none survived. Anatomical observations show collapsed cells associated with a high accumulation of calcium oxalate crystals and starch grains, as a response to water deficit. Titratable acidity concentration increased with seedling age, and CAM expression did not accelerate with soil water deficit. PMID:16936224

Ayala-Cordero, Gabriela; Terrazas, Teresa; López-Mata, Lauro; Trejo, Carlos

2006-01-01

337

Seedling development and evaluation of genetic stability of cryopreserved Dendrobium hybrid mature seeds.  

PubMed

Vitrification, a simple, fast, and recommended cryopreservation method for orchid germplasm conservation, was evaluated for Dendrobium hybrid "Dong Yai" mature seeds. The genetic stability of regenerated seedlings was also evaluated using flow cytometry. Mature seeds from this hybrid were submitted to plant vitrification solution (PVS2) for 0, 0.5, 1, 2, 3, 4, 5, or 6 h at 0 °C. Subsequently, they were plunged into liquid nitrogen (LN) at -196 °C for 1 h and recovered in half-strength Murashige and Skoog culture medium (1/2 MS), and seed germination was evaluated after 30 days. Seeds directly submitted to LN did not germinate after cryopreservation. Seeds treated with PVS2 between 1 and 3 h presented the best germination (between 51 and 58%), although longer exposure to PVS2 returned moderated germination (39%). Germinated seeds were further subcultured in P-723 culture medium and developed whole seedlings in vitro after 180 days, with no abnormal characteristics, diseases, or nutritional deficiencies. Seedlings were successfully acclimatized under greenhouse conditions with over 80% survival. Flow cytometry analysis revealed no chromosomal changes on vitrified seedlings, as well as seedlings germinated from the control treatment (direct exposure to LN). These findings indicate that vitrification is a feasible and safe germplasm cryopreservation method for commercial Dendrobium orchid hybrid conservation. PMID:24402568

Galdiano, Renato Fernandes; de Macedo Lemos, Eliana Gertrudes; de Faria, Ricardo Tadeu; Vendrame, Wagner Aparecido

2014-03-01

338

The Gluconeogenic Enzyme Phosphoenolpyruvate Carboxykinase in Arabidopsis Is Essential for Seedling Establishment  

PubMed Central

Phosphoenolpyruvate carboxykinase (PEPCK) catalyzes the conversion of oxaloacetate to phosphoenolpyruvate in the gluconeogenic production of sugars from storage oil in germinating oilseeds. Here, we present the results of analysis on PEPCK antisense Arabidopsis plants with a range of enzyme activities from 20% to 80% of wild-type levels. There is a direct correlation between enzyme activity and seedling establishment during early post-germinative growth, thus demonstrating the absolute requirement of PEPCK and gluconeogenesis in this process. Soluble sugar levels in the 35S-PCK1 antisense seedlings are reduced and seedling establishment can be rescued with an exogenous supply of sucrose. We observed an increase in the respiration of acetyl coenzyme A units released from fatty acid ?-oxidation and a corresponding decrease in the production of sugars with decreasing enzyme activity in 2-d-old antisense seedlings. The 35S-PCK1 antisense lines have a more extreme phenotype when compared with Arabidopsis mutants disrupted in the glyoxylate cycle. We conclude that the 35S-PCK1 antisense seedlings are compromised in the ability to use both storage lipid and storage protein through gluconeogenesis to produce soluble sugars.

Rylott, Elizabeth L.; Gilday, Alison D.; Graham, Ian A.

2003-01-01

339

Growth and survival response of potted Cupressus sempervirens seedlings to different soils.  

PubMed

In February 2001, one-year bareroot cypress (Cupressus sempervirens var. horizontalis) seedlings were replanted in plastic pot in a lowland nursery located in southern coast of the Caspian Sea (north of Iran). Soils of pots consisted of 1:1 sand:clay (A), pure sand (B), 2:1 sand:clay (C), 1:1:1 sand:clay:organic matter (D), 1:1:2 sand:clay:organic matter (E). In each soil treatment a high value of survival and growth was appeared in July and progressively decreased till November. In each month the seedlings grown on rich soils (D and E) had mostly greater growth and survival than on infertile soils. At the end of the first growing season seedling vitality differed significantly among the soils but did not differed notably in soil A with those in other soils. Survival rate was highest in the rich soils (D and E). Stem length as well as collar diameter performed the least growth on the poor soils (B and C). Like other characteristics measured, survival responded better to soils containing organic matter (D and E). It is concluded that generally characteristics of cypress seedling are suited by adding organic matter to sandy soils. This is while that poor nutrient available soil such as soil A produces a proper growth for cypress seedling, too. PMID:19069934

Tabari, Masoud; Saeidi, Hamid Reza; Alavi-Panah, Kazem; Basiri, Reza; Poormadjidian, Mohammad Reza

2007-04-15

340

Patterns of seed mass variation and their effects on seedling traits inAlliaria petiolata (Brassicaceae).  

PubMed

Seed mass is considered to be the least plastic component of reproductive yield. Yet, in invasive populations of garlic mustard, Alliaria petiolata, seed mass was highly variable (eightfold among populations, 2.5-7.5 fold within populations, two-threefold within individuals, and 1.4-1.8 fold within fruits). Variation in seed mass among populations explained nearly half of the total variance. Variation among seeds within fruits accounted for a further 25% of variance. Individual seed mass within a plant decreased with increased distance from the main stem, suggesting that access to parental resources limits seed size in a predictable manner. MANOVAs and Roy-Bargmann stepdown analyses revealed significant effects of seed mass, but not seed position (within a fruit or within an infructescence), on an array of subsequent seedling traits. Smaller seeds germinated significantly earlier, and seedlings from small seeds produced their first primary leaves significantly later and grew significantly taller. After accounting for seed mass as a covariate, only one seedling trait, date of first leaf emergence, was affected by seed position in a fruit. Differences in seed mass may therefore affect seedling recruitment via effects on early seedling growth in this weedy species. PMID:10636830

Susko, D J; Lovett-Doust, L

2000-01-01

341

Evaluation of nitrogen content in cabbage seedlings using hyper-spectral images  

NASA Astrophysics Data System (ADS)

Monitoring of nutrient status of crops is essential for better management of crop production. Nitrogen is one of the most important elements in fertilizer for the growth and yield of vegetable crops. In this study, nitrogen content of cabbage seedlings was evaluated using hyper-spectral images. Cabbage seedlings, cultured at five nitrogen fertilization levels, were planted in the 128-cell plug trays and grown in a phytotron at National Taiwan University. The images, ranged from 410 to 1090 nm, of cabbage seedlings were analyzed by a hyper-spectral imaging system consisting of CCD cameras with liquid crystal tunable filters (LCTF), which was developed in this study. The digital images of seedling canopies were processed including image segmentation, gray level calibration and absorbance conversion. Models including modified partial least square regression (MPLSR), step-wise multi-linear regression (SMLR) and artificial neural network with cross-learning strategy (ANN-CL) were developed for the determination of the nitrogen content in cabbage seedlings. The three significant wavelengths derived from SMLR model are 470, 710, and 1080; and the best result is obtained by ANN-CL model, in which rc=0.89, SEC=6.41 mg/g, rv=0.87, and SEV=6.96 mg/g. The ANN-CL model is more suitable for the remote sensing in precision agriculture applications because not only its model accuracy but also only 3 wavelengths are needed.

Chen, Suming; Chen, Chia-Tseng; Wang, Ching-Yin; Yang, I.-Chang; Hsiao, Shih-Chieh

2007-09-01

342

Comparative analysis of different methods for evaluating quality of Quercus ilex seedlings inoculated with Tuber melanosporum.  

PubMed

The quality of seedlings colonized by Tuber melanosporum is one of the main factors that contributes to the success or failure of a truffle crop. Truffle cultivation has quickly grown in European countries and elsewhere, so a commonly shared seedling evaluation method is needed. Five evaluation methods are currently published in the literature: three are used in Spain and two in France and Italy. Although all estimate the percentage colonization by T. melanosporum mycorrhizae, they do it in different ways. Two methods also estimate total number of mycorrhizae per seedling. Most are destructive. In this work, ten batches of holm oak seedlings inoculated with T. melanosporum from two different nurseries were evaluated by means of the five methods noted above. Some similarity was detected between the percentages of T. melanosporum mycorrhizae estimated by each method but not in their ability to assess the suitability of each batch. We discuss the advantages and disadvantages for each method and suggest approaches to reach consensus within the truffle culture industry for certifying mycorrhizal colonization by T. melanosporum and seedling quality. PMID:24522843

Andrés-Alpuente, Antonio; Sánchez, Sergio; Martín, María; Aguirre, Angel Javier; Barriuso, Juan J

2014-04-01

343

The combined effects of Pseudomonas fluorescens and Tuber melanosporum on the quality of Pinus halepensis seedlings.  

PubMed

The ecological, economic and social values of the ectomycorrhizal fungi of the black truffle found in the rural Mediterranean are well known. The inoculation of Pinus halepensis seedlings with mycorrhizal fungi and rhizobacteria can improve the morphology and physiology of the seedlings and benefit the regeneration of arid regions and the reintroduction of inocula of mycorrhizal fungi into these areas. Some rhizobacteria can improve the establishment and functioning of ectomycorrhizal symbiosis. In this study, seedlings of P. halepensis were inoculated with the mycorrhizal fungus Tuber melanosporum and the rhizobacteria Pseudomonas fluorescens CECT 844 under non-limiting greenhouse conditions. Five months after inoculation, we analysed the growth, water parameters (osmotic potential at saturation, osmotic potential at turgor loss and modulus of elasticity), concentrations of mycorrhizal colonies, nutrient concentration and nutrient contents (N, P, K, Ca, Mg and Fe) in roots and aerial parts of the seedlings. Subsequently, tests were performed to estimate the root growth potentials. None of the treatments changed the water parameters or growth potentials of the roots. The inoculations improved the growth and nutrient uptake of the seedlings, although the combination of P. fluorescens CECT 844 and T. melanosporum did not generally lead to a significant improvement over the positive effects of a simple inoculation of T. melanosporum; however, the addition of P. fluorescens CECT 844 did double the rate of the mycorrhization of T. melanosporum. These results may be promising for enhancing the cultivation of truffles. PMID:22068563

Dominguez, J A; Martin, A; Anriquez, A; Albanesi, A

2012-08-01

344

[Eco-physiological response of Quercus variabilis seedlings to increased atmospheric CO2 and N supply].  

PubMed

The effect of CO2 enhancement, nitrogen deposition and their interaction on the northern boundary (Zhuanghe in Liaoning Province) of Quercus variabilis seedlings was studied by controlling the CO2 concentration (700 micromol x mol(-1); 400 micromol x mol(-1)) and nitrogen level (non nitrogen fertilizer: CK; nitrogen fertilizer: 120 kg N x hm(-2)). The results showed that under elevated CO2 the Q. variabilis seedlings' leaf morphology, photosynthetic pigments and leaf nitrogen content tended to decrease, and the dark respiration rate decreased 63. 3% and soluble sugar increased 2.6%. Nitrogen deposition significantly promoted the Q. variabilis seedlings' leaf morphology and photosynthetic pigments, leading to increased leaf nitrogen content, decreased potassium content, and 26.7% of increase in nitrogen to potassium ratio. CO2 and N interaction played a significant role on promoting the Q. variabilis seedlings' leaf morphology and photosynthetic. The maximum net photosynthetic and light saturation point were 1.4 and 2.6 times of the control, while dark respiration and light compensation point decreased 65.9% and 50.0%, respectively. Elevated CO2 and nitrogen deposition had a positive effect on Q. variabilis seedlings to some degree, which might result in the movement of distribution boundary of Q. variabilis to north. PMID:24765838

Du, Qi-Ran; Lei, Jing-Pin; Liu, Jian-Feng; Wang, Peng-Cheng; Xiao, Wen-Fa; Pan, Lei

2014-01-01

345

Exploring the Natural Variation for Seedling Traits and Their Link with Seed Dimensions in Tomato  

PubMed Central

The success of germination, growth and final yield of every crop depends to a large extent on the quality of the seeds used to grow the crop. Seed quality is defined as the viability and vigor attribute of a seed that enables the emergence and establishment of normal seedlings under a wide range of environments. We attempt to dissect the mechanisms involved in the acquisition of seed quality, through a combined approach of physiology and genetics. To achieve this goal we explored the genetic variation found in a RIL population of Solanum lycopersicum (cv. Moneymaker) x Solanum pimpinellifolium through extensive phenotyping of seed and seedling traits under both normal and nutrient stress conditions and root system architecture (RSA) traits under optimal conditions. We have identified 62 major QTLs on 21 different positions for seed, seedling and RSA traits in this population. We identified QTLs that were common across both conditions, as well as specific to stress conditions. Most of the QTLs identified for seedling traits co-located with seed size and seed weight QTLs and the positive alleles were mostly contributed by the S. lycopersicum parent. Co-location of QTLs for different traits might suggest that the same locus has pleiotropic effects on multiple traits due to a common mechanistic basis. We show that seed weight has a strong effect on seedling vigor and these results are of great importance for the isolation of the corresponding genes and elucidation of the underlying mechanisms.

Willems, Leo A. J.; van Heusden, Adriaan W.; Ligterink, Wilco; Hilhorst, Henk W. M.

2012-01-01

346

Tolerance to Cadmium of Agave lechuguilla (Agavaceae) Seeds and Seedlings from Sites Contaminated with Heavy Metals  

PubMed Central

We investigated if seeds of Agave lechuguilla from contaminated sites with heavy metals were more tolerant to Cd ions than seeds from noncontaminated sites. Seeds from a highly contaminated site (Villa de la Paz) and from a noncontaminated site (Villa de Zaragoza) were evaluated. We tested the effect of Cd concentrations on several ecophysiological, morphological, genetical, and anatomical responses. Seed viability, seed germination, seedling biomass, and radicle length were higher for the non-polluted site than for the contaminated one. The leaves of seedlings from the contaminated place had more cadmium and showed peaks attributed to chemical functional groups such as amines, amides, carboxyl, and alkenes that tended to disappear due to increasing the concentration of cadmium than those from Villa de Zaragoza. Malformed cells in the parenchyma surrounding the vascular bundles were found in seedlings grown with Cd from both sites. The leaves from the contaminated place showed a higher metallothioneins expression in seedlings from the control group than that of seedlings at different Cd concentrations. Most of our results fitted into the hypothesis that plants from metal-contaminated places do not tolerate more pollution, because of the accumulative effect that cadmium might have on them.

Mendez-Hurtado, Alejandra; Rangel-Mendez, Rene; Flores, Joel

2013-01-01

347

Phloem transport velocity varies over time and among vascular bundles during early cucumber seedling development.  

PubMed

We use a novel dye-tracing technique to measure in vivo phloem transport velocity in cucumber (Cucumis sativus) plants during early seedling development. We focus on seedlings because of their importance in plant establishment and because they provide a simple source and sink model of phloem transport. The dye-tracing method uses a photodiode to track the movement of a bleach front of fluorescent dye traveling in the phloem from the cotyledons (source) to the roots (sink). During early seedling development, phloem transport velocity in this direction can change 2-fold depending on vascular connectivity and the number of actively growing sinks. Prior to leaf expansion, vascular bundles attached to the first developing leaf demonstrate a decline in basipetal phloem transport that can be alleviated by the leaf's removal. At this stage, seedlings appear carbon limited and phloem transport velocity is correlated with cotyledon area, a pattern that is apparent both during cotyledon expansion and after source area manipulation. When the first leaf transitions to a carbon source, seedling growth rate increases and basipetal phloem transport velocity becomes more stable. Because bundles appear to operate autonomously, transport velocity can differ among vascular bundles. Together, these results demonstrate the dynamic and heterogeneous nature of phloem transport and underline the need for a better understanding of how changes in phloem physiology impact growth and allocation at this critical stage of development. PMID:24072581

Savage, Jessica A; Zwieniecki, Maciej A; Holbrook, N Michele

2013-11-01

348

Effect of a longitudinally applied voltage upon the growth of Zea mays seedlings.  

PubMed

The electrical parameters that affect young seedling growth were investigated. Voltages ranging from 5 to 40 volts were applied longitudinally along the mesocotyl region of 4-day old Zea mays L. (cv Silver Queen) seedlings for periods of 3 or 4 hours. It was determined that: (a) making the tips of the seedlings electrically positive relative to the base strongly inhibited shoot growth at 5 volts, whereas the reverse polarity had no effect; (b) at higher voltages, making the tip of the seedlings negative caused less growth inhibition than the reverse polarity at each voltage level; (c) the higher the applied voltage the greater the degree of inhibition; and, (d) the more growth inhibition experienced by the plants the poorer, and slower, their recovery. Previous observations of a relationship between the amount of free indole-3-acetic acid in the mesocotyl cortex and the growth rate of the mesocotyl and of gravitropism-induced movement of labeled indole-3-acetic acid from the seed to the shoot lead to the prediction of a voltage-dependent gating of the movement of indole-3-acetic acid from the stele to the cortex. This provided the basis for attempting to alter the growth rate of seedlings by means of an applied voltage. PMID:11537877

Desrosiers, M F; Bandurski, R S

1988-01-01

349

Influence of germination date on Dioon edule (Zamiaceae) seedling tolerance to water stress.  

PubMed

Dioon edule seedling mortality is mostly attributed to dehydration by prolonged drought, even when they present xeromorphic characteristics like the adult plants. The effect of germination date (GD) and soil water deficit on seedling tolerance to water stress was assessed. The seedlings germinated and grown from mature seeds every month from December to April GD were selected to evaluate the leaf area, photosynthetic pigment content, crassulacean acid metabolism (CAM) activity, stomatal conductance (gs) and leaflet anatomy at soil water potential (?s) of 0.0 MPa (day 1), -0.1 MPa (day 40), -1.0 MPa (day 90), -1.5 MPa (day 130), and a control (0.0 MPa at day 130) to recognize differences due to leaf development. The seedlings shifted from C3 to CAM cycling when exposed to water stress at ?s of -1.0 MPa, like adult plants. The March-April GD seedlings with undeveloped sclerified hypodermis and stomata, presented reduced leaf area, lower Chlorophyll a/b ratio, higher CAM activity and midday partial stomatal closure when reached ?s of -1.0 MPa. These have higher probability of dehydration during severe drought (February-April) than those of the December-February GD with similar ?s. Plants used for restoration purposes must have full leaf development to increase the survival. PMID:24500792

Yáńez-Espinosa, Laura; Flores, Joel; Rodríguez Millán, Paulina S; Rubio Méndez, Gabriel

2014-05-01

350

H1 histone in developing and aging coleoptiles of etiolated wheat seedlings.  

PubMed

It has been established that the DNA and H1 histone contents in aged coleoptile of 8-day-old etiolated wheat seedling are about 40 and 30%, respectively, lower than those in young seedlings. H1 histone in wheat seedlings is represented as six electrophoretically different subfractions. The ratios of H1 histone subfractions in wheat coleoptile and initial leaf are similar. In contrast to some animal cells, apoptosis in wheat coleoptile is not accompanied by changes in the set and ratios of H1 histone subfractions. Aging of coleoptiles is associated with a progressive diminution of the H1 histone and DNA contents. H1 histone/DNA ratio in aged coleoptile is 1.5-2-fold higher than that in the young organs. Therefore, the content of H1 histone in chromatin of coleoptile decreases with age more slowly than DNA content. PMID:15527413

Smirnova, T A; Prusov, A N; Kolomijtseva, G Ya; Vanyushin, B F

2004-10-01

351

Seedling development in a Brassica napus diversity set and its relationship to agronomic performance.  

PubMed

Brassica napus L. is the leading European oilseed crop and has therefore a high economical importance. The objectives of our study were to examine (1) the patterns of phenotypic diversity in a species-wide B. napus germplasm set of 518 inbreds with respect to various seedling development, agronomic, and seed quality traits as well as (2) the interrelationship of the examined traits and their use in selection on correlated traits. The B. napus germplasm set was evaluated in greenhouse and field trials for several seedling development, agronomic, and seed quality traits. The traits were highly correlated within the individual trait categories and moderately correlated between the different trait categories. We observed differences in phenotypic diversity among the examined eight germplasm types. The reduction of phenotypic diversity was on average more pronounced for the seedling development traits than for the agronomic and seed quality traits, suggesting that plant breeders need to introgress new genetic variation with respect to the former. PMID:22782254

Körber, Niklas; Wittkop, Benjamin; Bus, Anja; Friedt, Wolfgang; Snowdon, Rod J; Stich, Benjamin

2012-10-01

352

A comparative field study of growth and survival of Sierran conifer seedlings  

SciTech Connect

This study is a comparison of seedling growth and survival of seven species of conifers that make up the mid-elevation Sierra Nevada mixed conifer forest--Abies concolor, Abies magnifica, Calocedrus decurrens, Pinus jeffreyi, Pinus lambertiana, Pinus ponderosa, and Sequoiadendron giganteum. The field experiment was designed to test the hypothesis that seedling demography is affected by the study species` relatively shade and drought tolerances. Six discrete treatments were created in the first experiment by using three elevations (1,600 m, 1,900, m, and 2,200 m) and two natural light levels (closed canopy shade and open gap sun) at each elevation. One or two-year old seedlings were planted in the ground in replicate plots in each treatment and followed for two growing seasons. Four responses were analyzed--survival, height growth, diameter growth, and mass growth (total mass as well as root mass and shoot mass separately).

Kern, R.A. [Duke Univ., Durham, NC (United States). Dept. of Botany] [Duke Univ., Durham, NC (United States). Dept. of Botany

1996-12-31

353

Phytotoxic and genotoxic effects of silver nanoparticles exposure on germinating wheat seedlings.  

PubMed

We investigated the effects of 1 and 10mgL(-1) AgNPs on germinating Triticum aestivum L. seedlings. The exposure to 10mgL(-1) AgNPs adversely affected the seedling growth and induced morphological modifications in root tip cells. TEM analysis suggests that the observed effects were due primarily to the release of Ag ions from AgNPs. To gain an increased understanding of the molecular response to AgNP exposure, we analyzed the genomic and proteomic changes induced by AgNPs in wheat seedlings. At the DNA level, we applied the AFLP technique and we found that both treatments did not induce any significant DNA polymorphisms. 2DE profiling of roots and shoots treated with 10mgL(-1) of AgNPs revealed an altered expression of several proteins mainly involved in primary metabolism and cell defense. PMID:24973586

Vannini, Candida; Domingo, Guido; Onelli, Elisabetta; De Mattia, Fabrizio; Bruni, Ilaria; Marsoni, Milena; Bracale, Marcella

2014-08-15

354

Nitrogen Assimilation and Protein Synthesis in Wheat Seedlings As Affected by Mineral Nutrition. I. Macronutrients 1  

PubMed Central

Deficiencies of each macronutrient (N, P, K, Ca. Mg, S, and Fe) decreased the specific activity of nitrate reductase from Triticum aestivum L. seedlings. Nitrate content was decreased by N, P, K, Ca, and Mg deficiencies and unaffected by S and Fe deficiencies. Glutamic acid dehydrogenase activity was decreased by N, P, and S deficiencies, unchanged by K deficiency, and increased by Ca, Mg, and Fe deficiencies. Glutamine synthetase activity closely paralleled nitrate reductase activity and was decreased by deficiencies of N, P, K, Ca, Mg, and S. Glutamic-oxaloacetic transaminase was not sensitive to macronutrient deficiencies. High 14C-leucine incorporation into tissue sections of N-, P-, K-, Ca-, and S-deficient seedlings did not appear indicative of protein synthesis rates in intact seedlings. Nutritional deficiencies apparently depleted endogenous amino acid pools and caused less inhibition of exogenous 14C-leucine incorporation into protein.

Harper, James E.; Paulsen, Gary M.

1969-01-01

355

Interactive effects of cadmium and acid rain on photosynthetic light reaction in soybean seedlings.  

PubMed

Interactive effects of cadmium (Cd(2+)) and acid rain on photosynthetic light reaction in soybean seedlings were investigated under hydroponic conditions. Single treatment with Cd(2+) or acid rain and the combined treatment decreased the content of chlorophyll, Hill reaction rate, the activity of Mg(2+)-ATPase, maximal photochemical efficiency and maximal quantum yield, increased initial fluorescence and damaged the chloroplast structure in soybean seedlings. In the combined treatment, the change in the photosynthetic parameters and the damage of chloroplast structure were stronger than those of any single pollution. Meanwhile, Cd(2+) and acid rain had the interactive effects on the test indices in soybean seedlings. The results indicated that the combined pollution of Cd(2+) and acid rain aggravated the toxic effect of the single pollution of Cd(2+) or acid rain on the photosynthetic parameters due to the serious damage to the chloroplast structure. PMID:22182775

Sun, Zhaoguo; Wang, Lihong; Chen, Minmin; Wang, Lei; Liang, Chanjuan; Zhou, Qing; Huang, Xiaohua

2012-05-01

356

Diversity of ectomycorrhizal fungi naturally established on containerised Pinus seedlings in nursery conditions.  

PubMed

The study examined the diversity of ectomycorrhizal fungi, naturally established on roots of containerised Pinus seedlings in a nursery, using PCR-RFLP and sequencing of the nuclear ribosomal internal transcribed spacer. Seventy-two samples, including ectomycorrhizae and fruit bodies, were examined. Molecular typing assigned the fungal symbionts to four ectomycorrhizal Boletales: Rhizopogon rubescens, Suillus bovinus, S. variegatus, and R. luteolus. R. rubescens was abundant (37.5%), while Suillus and R. luteolus species were moderately established (25-26%) and rare (2.8%), respectively. In addition, Rhizopogon species colonised P. nigra ssp. salzmannii seedlings, whereas Suillus species were identified on Pinus nigra ssp. nigra seedlings. The diversity and the ability of these naturally established symbionts under artificial nursery conditions were discussed. The molecular survey investigated here should contribute to successful monitoring of mycorrhizal application under both nursery and plantation conditions. PMID:15782937

El Karkouri, Khalid; Martin, Francis; Douzery, J P Emmanuel; Mousain, Daniel

2005-01-01

357

Foliar Iron Spray Potentiates Growth of Seedlings on Iron-free Media  

PubMed Central

Growth of bean (Phaseolus vulgaris cv. `Brittle Wax') seedlings in iron-free media caused large reductions in root size and dye reduction capacity. Shoot growth was also severely retarded and the classical symptoms of chlorosis were observed. A single prophylactic spray of FeSO4, applied to the primary leaves of 7-day seedlings, enabled subsequent growth to equal that obtained when iron was continuously supplied to the roots over a 12-day period, although chlorophyll levels were lower. By adding a silicone-based surfactant to FeSO4 spray solutions, the burn damage normally caused to seedlings by such sprays was largely eliminated and the irreversible adsorption of iron increased. Foliar spray of an iron chelate (ferric ethylenediaminedi (o-hydroxyphenylacetic acid)) were less effective than those of FeSO4.

Neumann, Peter M.; Prinz, Rivka

1975-01-01

358

Influence of Light and Ambient Carbon Dioxide Concentration on Nitrate Assimilation by Intact Barley Seedlings 1  

PubMed Central

The influence of light, dark, and ambient CO2 on nitrate assimilation in 8- to 9-day-old barley seedlings was studied. To develop the photosynthetic apparatus fully, the seedlings were grown in nitrogen-free Hoagland solution for 5 days in darkness followed by 3 days in continuous light. The seedlings reduced nitrate and nitrite in both light and dark, although more slowly in darkness. The slower nitrate reduction in darkness was not due to decreased uptake, since the steady-state internal concentration of nitrate was doubled. The faster nitrate reduction in light was attributed to recent products of photosynthetic CO2 fixation supplying reducing energy, possibly by shuttle reactions between chloroplasts and cytoplasm. In carbohydrate-deficient tissue, it appeared that recently fixed photosynthate could supply all of the energy required for nitrate reduction. When sufficient metabolites were present in the green tissue, light was not obligatory for the reduction of nitrate and nitrite.

Aslam, Muhammad; Huffaker, Ray C.; Rains, D. William; Rao, K. Prasad

1979-01-01

359

Nitrogen deficiency system is helpful in characterizing regulation mechanisms of ectopic triacylglycerol accumulation in Arabidopsis seedlings  

PubMed Central

Triacylglycerol (TAG) is the major storage component accumulated in seed. However the regulatory mechanism of TAG synthesis and accumulation in non-seed tissues remains unknown. Recently, we found that nitrogen (N) deficiency (0.1mM N) caused an inducement of TAG biosynthesis in Arabidopsis seedlings. ABSCISIC ACID INSENSITIVE 4 (ABI4) was essential for the activation of Acyl-CoA:diacylglycerol acyltransferase1(DGAT1) expression during N deficiency in Arabidopsis seedlings. In this addendum, we further discussed the approaches to provide a net increase in total oil production in higher plants by using the low N platform. First, the N-deficient seedlings can be used to determine the key factors that regulate the ectopic expression of key genes in TAG metabolism. Second, the research on the relationship between TAG homeostasis and cell division will be helpful to find the key factors that specifically regulate TAG accumulation under the nutrient-limited condition.

Yang, Yang; Yu, Xiangchun; Song, Lianfen; An, Chengcai

2011-01-01

360

[Effects of light quality on photosynthetic pigment contents and photosynthetic characteristics of peanut seedling leaves].  

PubMed

Abstract: This study explored the effects of different light quality on photosynthetic pigment contents and photosynthetic characteristics of peanut (Qinhua 6) seedling leaves. The results showed that, compared with natural light, blue light (445-470 nm) could significantly improve the specific leaf area (SLA), chlorophyll a/b value and carotenoid content of peanut seedlings. Meanwhile, the net photosynthetic rate, stomatal conductance, and transpiration rate were higher, the intercellular CO2 content was lower, and the photosynthetic efficiency was improved significantly under blue light. Red light (610-660 nm) could improve the chlorophyll content significantly, and reduce SLA, chlorophyll a/b value and carotenoid content, with a lower photosynthetic efficiency than natural light. Green light (515-520 nm) and yellow light (590-595 nm) were not conducive to photosynthetic pigment accumulation of leaves, and significantly inhibited leaf photosynthesis of peanut seedlings. PMID:24830249

Yan, Meng-Meng; Wang, Ming-Lun; Wang, Hong-Bo; Wang, Yue-Fu; Zhao, Chang-Xing

2014-02-01

361

Biological Control of Damping-Off of Alfalfa Seedlings with Bacillus cereus UW85  

PubMed Central

We explored the potential of biological control of alfalfa (Medicago sativa L.) seedling damping-off caused by Phytophthora megasperma f. sp. medicaginis by screening root-associated bacteria for disease suppression activity in a laboratory bioassay. A total of 700 bacterial strains were isolated from the roots of field-grown alfalfa plants by using Trypticase soy agar. A simple, rapid assay was developed to screen the bacteria for the ability to reduce the mortality of Iroquois alfalfa seedlings that were inoculated with P. megasperma f. sp. medicaginis zoospores. Two-day-old seedlings were planted in culture tubes containing moist vermiculite, and each tube was inoculated with a different bacterial culture. Sufficient P. megasperma f. sp. medicaginis zoospores were added to each tube to result in 100% mortality of control seedlings. Of the 700 bacterial isolates tested, only 1, which was identified as Bacillus cereus and designated UW85, reduced seedling mortality to 0% in the initial screen and in two secondary screens. Both fully sporulated cultures containing predominantly released spores and sterile filtrates of these cultures of UW85 were effective in protecting seedlings from damping-off; filtrates of cultures containing predominantly vegetative cells or endospores inside the parent cell had low biocontrol activity. Cultures grown in two semidefined media had significantly greater biocontrol activities than cultures grown in the complex tryptic soy medium. In a small-scale trial in a field infested with P. megasperma f. sp. medicaginis, coating seeds with UW85 significantly increased the emergence of alfalfa. The results suggest that UW85 may have potential as a biocontrol agent for alfalfa damping-off, thus providing an alternative to current disease control strategies. Images

Handelsman, Jo; Raffel, Sandra; Mester, Ellen H.; Wunderlich, Lynn; Grau, Craig R.

1990-01-01

362

Mechanisms associated with tolerance to flooding during germination and early seedling growth in rice (Oryza sativa)  

PubMed Central

Background and Aims Flooding slows seed germination, imposes fatalities and delays seedling establishment in direct-seeded rice. This study describes responses of contrasting rice genotypes subjected to flooding or low oxygen stress during germination and discusses the basis of tolerance shown by certain cultivars. Methods In one set of experiments, dry seeds were sown in soil and either watered normally or flooded with 10 cm of water. Seedling survival and shoot and root growth were assessed and seed portions of germinating seedlings were assayed for soluble sugars and starch concentrations. The whole germinating seedlings were assayed for amylase and peroxidase activities and for ethylene production. Activities of enzymes associated with anaerobic respiration were examined and gene expression was analysed separately with seeds germinating under different amounts of dissolved oxygen in dilute agar. Key Results Flooding during germination reduced survival but to a lesser extent in tolerant genotypes. Starch concentration in germinating seeds decreased while sugar concentration increased under flooding, but more so in tolerant genotypes. Amylase activity correlated positively with elongation (r = 0·85 for shoot and 0·83 for root length) and with plant survival (r = 0·92). Tolerant genotypes had higher amylase activity and higher RAmy3D gene expression. Ethylene was not detected in seeds within 2 d after sowing, but increased thereafter, with a greater increase in tolerant genotypes starting 3 d after sowing. Peroxidase activity was higher in germinating seeds of sensitive genotypes and correlated negatively with survival. Conclusions Under low oxygen stress, tolerant genotypes germinate, grow faster and more seedlings survive. They maintain their ability to use stored starch reserves through higher amylase activity and anaerobic respiration, have higher rates of ethylene production and lower peroxidase activity as germinating seeds and as seedlings. Relevance of these traits to tolerance of flooding during germination and early growth is discussed.

Ismail, Abdelbagi M.; Ella, Evangelina S.; Vergara, Georgina V.; Mackill, David J.

2009-01-01

363

Growth and phenology of seedlings of four contrasting slash pine families in ten nitrogen regimes.  

PubMed

Seedlings of two fast- and two slow-growing families of slash pine, Pinus elliottii Englm. var. elliottii, were grown in a greenhouse for one growing season in one of 10 nitrogen (N) regimes. Increasing the N concentration in the nutrient solution resulted in both increased growth rates during the exponential growth phase and extended duration of the growing season. The two components of total height, free growth (epicotyl length to the first bud) and summer growth (height growth after the first bud), both increased significantly with increasing N concentrations up to 40-60 mg l(-1) but decreased at N concentrations above 180 mg l(-1). Compared to seedlings grown in the presence of an optimum N concentration, seedlings grown in the presence of trace amounts of N were smaller and had less summer growth as a percentage of total growth, earlier cessation of height growth, fewer flushes, lower shoot/root ratio, higher root fibrosity, and lower N concentrations in all seedling tissues. Compared to slow-growing families, fast-growing families had more summer height growth, more flushes and later growth cessation, higher shoot/root ratios and higher root fibrosity at all N concentrations. In the presence of an optimum or higher concentration of N, the fast-growing families also had higher needle and total N concentrations than the slow-growing families. Strong family by N-treatment interactions occurred for height, phenology and biomass traits because of the extra responsiveness of one family to increasing N concentration. Several seedling traits were identified that appear promising for predicting field performance in slash pine. The results indicated that the nutrient environment greatly influences genetic expression (e.g., family patterns of summer growth were most closely related to field rankings for seedlings in the trace-N treatment). PMID:14969950

Dewald, L; White, T L; Duryea, M L

1992-10-01

364

Carbon translocation patterns associated with new root proliferation during episodic growth of transplanted Quercus rubra seedlings.  

PubMed

Patterns of carbon allocation in northern red oak (Quercus rubra L.), characterized by episodic growth through recurrent single-season flushing, vary by growth stage. To examine post-transplant timing and carbohydrate sources for new root growth, dormant, bare-root, half-sibling northern red oak seedlings were transplanted to pots and placed in a favorable growth chamber environment. Unlabeled seedlings were harvested at transplant and at the bud swell stage. After leaf emergence, seedlings were exposed to (14)CO(2) at the linear shoot, linear leaf or lag growth stages. Seedlings were then placed in a growth room for 48 h to allow for translocation of (14)C-labeled current photosynthate and its stabilization in sink component plant parts. Seedlings were subsequently harvested and tissue (14)C:(12)C ratio analyzed. New root growth began during the linear shoot growth stage. However, no increase in (14)C:(12)C ratio was found in new roots until the linear leaf and lag growth stages, indicating a downward shift in translocation of current photosynthate to fuel new root growth. In old roots, (14)C:(12)C ratio increased at the lag stage. Our results indicate that both stored carbohydrates and current photosynthate contribute to new root growth of transplanted northern red oak seedlings; stored carbohydrates promote initial new root proliferation, whereas current photosynthate assumes a greater role as new leaves mature and the flush terminates. Optimizing nursery practices to increase carbohydrate reserves may reduce the time required to establish root-soil contact and facilitate early post-planting survival. PMID:18450576

Sloan, Joshua L; Jacobs, Douglass F

2008-07-01

365

Organ-coordinated response of early post-germination mahogany seedlings to drought.  

PubMed

Water deficit tolerance during post-germination stages is critical for seedling recruitment. In this work, we studied the effect of water deficit on morphological and biochemical responses in different organs of newly germinated mahogany (Swietenia macrophylla King) seedlings, a woody species that occurs in the Amazon rainforest. The root : shoot ratio increased under water deficit. The leaf number and water potential were not altered, although reductions in leaf area and stomatal conductance were observed. Osmotic potential became more negative in leaves of seedlings under severe stress. Water deficit increased fructose, glucose, sucrose and myo-inositol levels in leaves. Stems accumulated fructose, glucose and l-proline. Nitric oxide (NO) levels increased in the vascular cylinder of roots under severe stress while superoxide anion levels decreased due to augmented superoxide dismutase activity in this organ. Water deficit induced glutathione reductase activity in both roots and stems. Upon moderate or severe stress, catalase activity decreased in leaves and remained unaffected in the other seedling organs, allowing for an increase of hydrogen peroxide (H2O2) levels in leaves. Overall, the increase of signaling molecules in distinct organs-NO in roots, l-proline in stems and H2O2 and myo-inositol in leaves-contributed to the response of mahogany seedlings to water deficit by triggering biochemical processes that resulted in the attenuation of oxidative stress and the establishment of osmotic adjustment. Therefore, this body of evidence reveals that the development of newly germinated mahogany seedlings may occur in both natural habitats and crop fields even when water availability is greatly limited. PMID:24690672

Horta, Lívia P; Braga, Márcia R; Lemos-Filho, José P; Modolo, Luzia V

2014-04-01

366

Ectomycorrhizas naturally established in Nothofagus nervosa seedlings under different cultivation practices in a forest nursery.  

PubMed

Mycorrhizas are mutualistic associations between soil fungi and plant roots which usually improve water and nutrient uptake, influencing plant fitness. Nothofagus nervosa (Raulí) is an ecologically and economically important species of South American temperate forests. Since this native tree species yields valuable timber, it was overexploited and its natural distribution area was critically reduced, so it is currently included in domestication and conservation programs. Among the factors that should be considered in these programs are the ectomycorrhizas (EcM), which would be important for the successful establishment and survival of outplanted seedlings. The aim of this work was to analyze the abundance and diversity of EcM in N. nervosa nursery-cultivated seedlings assessed by morphotyping, fungal isolation, and DNA sequencing. Arbuscular mycorrhiza (AM) occurrence was also studied. A 2-year trial was conducted following the cultivation conditions used for domestication programs. Seedlings were cultivated under two different cultivation practices (greenhouse and nursery soil) without artificial inoculation of mycorrhizal fungi. Seedlings' roots were examined at different times. It was observed that they developed EcM between 6 and 12 months after germination and AMs were not detected in any plant. The most abundant ectomycorrhizal fungi present in seedlings' roots were Tomentella ellisii (Basidiomycota) and an unidentified fungus named Ascomicetous EcM sp. 1. Abundance and diversity of EcM varied between the two cultivation techniques analyzed in this study, since seedlings that continued growing in the greenhouse had higher colonization values, but those transplanted to the nursery soil were colonized by a higher diversity of fungal taxa. PMID:23636582

Fernández, Natalia V; Marchelli, Paula; Fontenla, Sonia B

2013-10-01

367

Climatic control of bud burst in young seedlings of nine provenances of Norway spruce.  

PubMed

Detailed knowledge of temperature effects on the timing of dormancy development and bud burst will help evaluate the impacts of climate change on forest trees. We tested the effects of temperature applied during short-day treatment, duration of short-day treatment, duration of chilling and light regime applied during forcing on the timing of bud burst in 1- and 2-year-old seedlings of nine provenances of Norway spruce (Picea abies (L.) Karst.). High temperature during dormancy induction, little or no chilling and low temperature during forcing all delayed dormancy release but did not prevent bud burst or growth onset provided the seedlings were forced under long-day conditions. Without chilling, bud burst occurred in about 20% of seedlings kept in short days at 12 degrees C, indicating that young Norway spruce seedlings do not exhibit true bud dormancy. Chilling hastened bud burst and removed the long photoperiod requirement, but the effect of high temperature applied during dormancy induction was observed even after prolonged chilling. Extension of the short-day treatment from 4 to 8 or 12 weeks hastened bud burst. The effect of treatments applied during dormancy development was larger than that of provenance; in some cases no provenance effect was detected, but in 1-year-old seedlings, time to bud burst decreased linearly with increasing latitude of origin. Differences among provenances were complicated by different responses of some origins to light conditions under long-day forcing. In conclusion, timing of bud burst in Norway spruce seedlings is significantly affected by temperature during bud set, and these effects are modified by chilling and environmental conditions during forcing. PMID:18055441

Sřgaard, Gunnhild; Johnsen, Oystein; Nilsen, Jarle; Junttila, Olavi

2008-02-01

368

Global gene expression responses to waterlogging in leaves of rape seedlings.  

PubMed

Soil waterlogging is a serious constraint to crop production. We investigated the physiological responses of rape (Brassica napus L.) seedlings to waterlogging stress and analyzed global gene transcription responses in the aerial leaves of waterlogged rape seedlings. Seedlings of 'Tammi' and 'Youngsan' cultivars were subjected to waterlogging for 3 and 6 days and recovery for 5 days. Waterlogging stress caused a significant decrease in leaf chlorophyll content and premature senescence of the leaves. Maximal quantum efficiency of PSII (F(v)/F(m)) decreased in the waterlogged seedlings compared with the control plants. To evaluate whether the observed physiological changes in the leaves are associated with the differential regulation of gene expression in response to waterlogging stress, we analyzed the global transcriptional profile of leaves of 'Tammi' seedlings that were exposed to waterlogging for a short period (36 and 72 h). SolexaQA RNA-seq analysis revealed that a total of 4,484 contigs (8.5 %) of all contigs assayed (52,747) showed a twofold change in expression after 36 h of the start of waterlogging and 9,659 contigs (18.3 %) showed a twofold change after 72 h. Major genes involved in leaf photosynthesis, including light reactions and carbon-fixing reactions, were downregulated, while a number of genes involved in the scavenging of reactive oxygen species, degradation (proteins, starch, and lipids), premature senescence, and abiotic stress tolerance were upregulated. Transcriptome analysis data suggested that the aerial leaves of waterlogged rape seedlings respond to hypoxia by regulating the expression of diverse genes in the leaves. PMID:24384821

Lee, Yong-Hwa; Kim, Kwang-Soo; Jang, Young-Seok; Hwang, Ji-Hye; Lee, Dong-Hee; Choi, In-Hu

2014-02-01

369

Modeling forest floor contribution to phosphorus supply to maritime pine seedlings in two-layered forest soils  

Microsoft Academic Search

The quantitative contribution of the forest floor to P nutrition of maritime pine seedlings was experimentally determined by Jonard et al. (2009) in a greenhouse experiment using the radio-isotopic labeling. To extend the results of the experiment on a known mineral soil, a modeling approach was developed to predict P uptake of maritime pine seedlings growing in a mineral soil

Mathieu Jonard; Laurent Augusto; Emmanuel Hanert; David L. Achat; Mark R. Bakker; Christian Morel; Alain Mollier; Sylvain Pellerin

2010-01-01

370

An Analysis to the Driving Forces for Water and Salt Absorption in Roots of Maize Seedlings Under Salt Stress  

Microsoft Academic Search

When maize seedlings were subjected to salt stress, a decline in root xylem pressure was observed within seconds, followed by a gradual increase in Na+ deposition in the seedlings. The magnitude of xylem pressure response was positively correlated with, but not proportional to the intensity of the stress. A continuous recording of the xylem pressure profile showed that self-regulation of

Jian-jun ZHU; Xin-fu BAI; Qing-mei BU; Xiao-man JIANG

2010-01-01

371

Effects of hardened wood ash on microbial activity, plant growth and nutrient uptake by ectomycorrhizal spruce seedlings  

Microsoft Academic Search

Plant growth, nutrient uptake, microbial biomass and activity were studied in pot systems containing spruce seedlings colonised with different ectomycorrhizal fungi from an ash-fertilised forest. The seedling root systems were enclosed in mesh bags inside an outer compartment containing crushed, hardened wood ash. Three different species of mycorrhizal fungi and a non-mycorrhizal control were exposed to factorial combinations of ash

Shahid Mahmood; Roger D Finlay; Ann-Mari Fransson; Hĺkan Wallander

2003-01-01

372

The Window of Desiccation Tolerance Shown by Early-Stage Germinating Seedlings Remains Open in the Resurrection Plant, Xerophyta viscosa  

PubMed Central

Resurrection plants are renowned for their vegetative desiccation tolerance (DT). While DT in vegetative tissues is rare in angiosperms, it is ubiquitous in mature orthodox seeds. During germination, seedlings gradually lose DT until they pass a point of no return, after which they can no longer survive dehydration. Here we investigate whether seedlings of the resurrection plant Xerophyta viscosa ever lose the capacity to establish DT. Seedlings from different stages of germination were dehydrated for 48 hours and assessed for their ability to recover upon rehydration. While a transient decline in the ability of X. viscosa seedlings to survive dehydration was observed, at no point during germination was the ability to re-establish DT completely lost in all seedlings. Pre-treatment of seedlings with PEG or sucrose reduced this transient decline, and improved the survival rate at all stages of germination. Additionally, we observed that the trait of poikilochlorophylly (or loss of chlorophyll) observed in adult X. viscosa leaves can be induced throughout seedling development. These results suggest that the window of DT seen in germinating orthodox seeds remains open in X. viscosa seedlings and that vegetative DT in Xerophyta species may have evolved from the ability to retain this program through to adulthood.

Lyall, Rafe; Ingle, Robert A.; Illing, Nicola

2014-01-01

373

Development of red oak seedlings using plastic shelters on hardwood sites in West Virginia. Forest Service research paper (Final)  

Microsoft Academic Search

Plastic shelters were used to grow red oak seedlings on good-to-excellent Appalachian hardwood growing sites in north central West Virginia. Preliminary results indicate that shelters have the potential to stimulate development of red oak seedlingheight growth, especially if height growth continues once the seedling tops are above the 5-foot-tall shelters.

1993-01-01

374

Development of red oak seedlings using plastic shelters on hardwood sites in West Virginia. Forest Service research paper (Final)  

SciTech Connect

Plastic shelters were used to grow red oak seedlings on good-to-excellent Appalachian hardwood growing sites in north central West Virginia. Preliminary results indicate that shelters have the potential to stimulate development of red oak seedlingheight growth, especially if height growth continues once the seedling tops are above the 5-foot-tall shelters.

Smith, H.C.

1993-04-01

375

Effects of salinity on leaf characteristics and CO 2 \\/H 2 O exchange of Kandelia candel (L.) Druce seedlings  

Microsoft Academic Search

Effects of salinities on leaf characteristics and CO 2 \\/H 2 O exchange of mangrove species Kandelia candel seedlings were studied in a pot experiment. The seedlings grown in salinity of 50‰ caused a strong reduction in the rate of growth, but their leaves were black-green, smaller and less expanded or distorted than those of plants in the control and

D.-L. QIU; P. Lin

2007-01-01

376

The combined impacts of deep shade and drought on the growth and biomass allocation of shade-tolerant woody seedlings  

Microsoft Academic Search

To test whether the impact of drought on the growth and biomass allocation of first-season shade-tolerant woody seedlings in low irradiance differs from that in high irradiance, seedlings of Viburnum lantana, V. opulus, V. tinus and Hedera helix were grown in pots at two watering frequencies 2 three irradiances. Hypotheses in the recent literature variously predict that drought will have

Lawren Sack; Peter J. Grubb

2002-01-01

377

Maize seed coatings and seedling sprayings with chitosan and hydrogen peroxide: their influence on some phenological and biochemical behaviors  

PubMed Central

Objective: To evaluate the effect of chitosan (CH) and hydrogen peroxide (H2O2) seed coatings and seedling sprinklings on two different maize varieties by measuring their phenology, the H2O2 presence, the catalase (CAT) activity, and the protein quantity. Methods: Seven groups of ten seeds for each maize variety were treated with CH (2% (20 g/L) and 0.2% (2 g/L)) or H2O2 (8 mmol/L) by coating, sprinkling, or both. Germination and seedling growth were measured. One month after germination, the presence of H2O2 in seedlings in the coated seed treatments was evaluated. Protein content and CAT activity were determined under all treatments. Results: H2O2 seed coating enhanced the germination rate and increased seedling and stem length in the quality protein maize (QPM) variety. Seedlings had a higher emergence velocity under this treatment in both varieties. CH and H2O2 sprinklings did not have an effect on seedling phenology. Exogenous application of H2O2 promoted an increase of endogenous H2O2. CH and H2O2 seedling sprinkling increased the protein content in both maize varieties, while there was no significant effect on the CAT activity of treated seeds and seedlings. Conclusions: CH and H2O2 enhance some phenological and biochemical features of maize depending on their method of application.

Lizarraga-Paulin, Eva-Guadalupe; Miranda-Castro, Susana-Patricia; Moreno-Martinez, Ernesto; Lara-Sagahon, Alma-Virginia; Torres-Pacheco, Irineo

2013-01-01

378

Herbivory has a greater impact in shade than in sun: response of Quercus pyrenaica seedlings to multifactorial environmental variation  

Microsoft Academic Search

Many biotic and abiotic factors affect seedling establishment in woody plants. In Mediterranean environ- ments, the major factors affecting tree regeneration are light, water, and herbivory. We investigated the response of some morphological and chemical traits of Quercus pyrenaica Willd. seedlings to simulated herbivory (hand removal of 50% of the aerial mass) and two levels of light (sun vs. shade)

Elena Baraza; José M. Gómez; José A. Hódar; Regino Zamora

2004-01-01

379

Anthocyanin formation in turnip seedlings ( Brassica rapa L.): Evidence for two light steps in the biosynthetic pathway  

Microsoft Academic Search

Summary In turnip seedlings, anthocyanin synthesis can be induced with light as soon as water uptake enables the seed coat to be removed. In very young seedlings the main site of production is in the cotyledons but this moves to the hypocotyl when the period of dark growth, before transfer to the light, is increased. The total amount of anthocyanin

Renate Grill; Daphne Vince

1964-01-01

380

The effects of size of opening in vegetation and litter cover on seedling establishment of goldenrods ( Solidago spp.)  

Microsoft Academic Search

We investigated the effects of size of opening in the vegetation and litter cover on seedling establishment of two species of goldenrods (Solidago spp.) in an abandoned field in southwestern Michigan, U.S.A. Seeds of S. canadensis and S. juncea were sown into clipped plots, ranging from 0 cm (control, unclipped) to 100 cm in diameter, with and without litter. Seedling

Deborah E. Goldberg; Patricia A. Werner

1983-01-01

381

Is temporal variation of seedling communities determined by environment or by seed arrival? A test in a neotropical forest  

Microsoft Academic Search

Summary 1 Both spatial and temporal processes are assumed to play an important role in driving seedling dynamics. We assessed the magnitude of these two processes in a neotropical forest in French Guiana. We first quantified temporal changes in seed- ling community structure, then evaluated the relative importance of environmental heterogeneity and temporal fluctuations in seed arrival in determining seedling

NATALIA NORDEN; JÉRÔME CHAVE; ADELINE CAUBČRE; PATRICK CHÂTELET; NICOLE FERRONI; PIERRE-MICHEL FORGET; CHRISTOPHE THÉBAUD

2007-01-01

382

Taxonomic scale-dependence of habitat niche partitioning and biotic neighbourhood on survival of tropical tree seedlings  

PubMed Central

In order to differentiate between mechanisms of species coexistence, we examined the relative importance of local biotic neighbourhood, abiotic habitat factors and species differences as factors influencing the survival of 2330 spatially mapped tropical tree seedlings of 15 species of Myristicaceae in two separate analyses in which individuals were identified first to species and then to genus. Using likelihood methods, we selected the most parsimonious candidate models as predictors of 3 year seedling survival in both sets of analyses. We found evidence for differential effects of abiotic niche and neighbourhood processes on individual survival between analyses at the genus and species levels. Niche partitioning (defined as an interaction of taxonomic identity and abiotic neighbourhood) was significant in analyses at the genus level, but did not differentiate among species in models of individual seedling survival. By contrast, conspecific and congeneric seedling and adult density were retained in the minimum adequate models of seedling survival at species and genus levels, respectively. We conclude that abiotic niche effects express differences in seedling survival among genera but not among species, and that, within genera, community and/or local variation in adult and seedling abundance drives variation in seedling survival. These data suggest that different mechanisms of coexistence among tropical tree taxa may function at different taxonomic or phylogenetic scales. This perspective helps to reconcile perceived differences of importance in the various non-mutually exclusive mechanisms of species coexistence in hyper-diverse tropical forests.

Queenborough, Simon A.; Burslem, David F. R. P.; Garwood, Nancy C.; Valencia, Renato

2009-01-01

383

Differential grazing by the mollusc Arion hortensis Fér. on cyanogenic and acyanogenic seedlings of the white clover, Trifolium repens L  

Microsoft Academic Search

The average amount of releasable cyanide in cyanogenic seedlings of white clover was found to increase by a third from age 5 days to age 35 days. Over this period levels of cyanide decrease in cotyledons, but increase in stems and young leaves.The slug, Arion hortensis was introduced to mixed populations of mostly cyanogenic and mostly acyanogenic seedlings of white

J C Horrill; A J Richards

1986-01-01

384

Bacterial stimulation of adventitious rooting on in vitro cultured slash pine (Pinus elliottii Engelm.) seedling explants.  

PubMed

A bacterium has been isolated that initiates adventitious rooting when co-cultured under in vitro conditions with seedling-produced hypocotylary explants of slash pine (Pinus elliottii). Rooting efficiencies produced through bacterial-explant co-culture range from approximately 15% to greater than 90% over non-treated controls. Explant exposure to the root inducing bacterium has produced no obvious pathology in the regenerated plantlets. Seedling explants rooted by bacterial-explant co-culture have been successfully transitioned to ambient greenhouse conditions. PMID:24178418

Burns, J A; Schwarz, O J

1996-02-01

385

2,3-Epoxybrassinosteroids are intermediates in the biosynthesis of castasterone in seedlings of Secale cereale.  

PubMed

The involvement of the 2,3-epoxybrassinosteroids secasterone and 2,3-diepisecasterone in the biosynthesis of castasterone has been demonstrated in seedlings of Secale cereale by LC-ESI-MS. Deuterated secasterone, upon administration to rye seedlings, was incorporated into castasterone and its 2beta- and 3beta-epimers. Administration of deuterated 2,3-diepisecasterone resulted in castasterone and 2-epicastasterone. A biosynthetic subpathway from typhasterol/teasterone via 2,3-epoxybrassinosteroid intermediates to castasterone is discussed. PMID:15649512

Antonchick, Andrey; Svatos, Ales; Schneider, Bernd; Konstantinova, Olga V; Zhabinskii, Vladimir N; Khripach, Vladimir A

2005-01-01

386

Drought sensitivity of red spruce seedlings affected by precipitation chemistry. [Picea rubens  

SciTech Connect

Red spruce seedlings that had been exposed to a combination of simulated rain of pH 4.1 and mist of pH 3.6 were more severely affected by a drought regime than were seedlings treated with rain and mist of pH 5.1. The increased drought susceptibility, which was manifested in lower xylem water potentials and a greater reduction in photosynthesis, was not a result of altered physiological resistance, but was an indirect effect of a stimulation of needle growth by nitrogen fertilization, which increased plant water use and the severity of the drought.

Norby, R.J.; Taylor, G.E. Jr.; McLaughlin, S.B.; Gunderson, C.A.

1986-01-01

387

Response of seedlings growth of Pinus sylvestriformis to atmospheric CO 2 enrichment in Changbai Mountain  

Microsoft Academic Search

The biomass and ratio of root-shoot ofPinus sylvestriformis seedlings at CO2 concentration of 700 ?L·L?1 and 500 ?L·L?1 were measured using open-top chambers (OTCs) in Changbai Mountain during Jun. to Oct. in 1999. The results showed that doubling\\u000a CO2 concentration was benefit to seedling growth of the species (500 ?L·L?1 was better than 700 ?L·L?1) and the biomass production was

Han Shijie; Wang Chenrui; Zhang Junhui; Zou Chunjing; Zhou Yumei; Wang Xiaochun

1999-01-01

388

Herbivory on temperate rainforest seedlings in sun and shade: resistance, tolerance and habitat distribution.  

PubMed

Differential herbivory and/or differential plant resistance or tolerance in sun and shade environments may influence plant distribution along the light gradient. Embothrium coccineum is one of the few light-demanding tree species in the temperate rainforest of southern South America, and seedlings are frequently attacked by insects and snails. Herbivory may contribute to the exclusion of E. coccineum from the shade if 1) herbivory pressure is greater in the shade, which in turn can result from shade plants being less resistant or from habitat preferences of herbivores, and/or 2) consequences of damage are more detrimental in the shade, i.e., shade plants are less tolerant. We tested this in a field study with naturally established seedlings in treefall gaps (sun) and forest understory (shade) in a temperate rainforest of southern Chile. Seedlings growing in the sun sustained nearly 40% more herbivore damage and displayed half of the specific leaf area than those growing in the shade. A palatability test showed that a generalist snail consumed ten times more leaf area when fed on shade leaves compared to sun leaves, i.e., plant resistance was greater in sun-grown seedlings. Herbivore abundance (total biomass) was two-fold greater in treefall gaps compared to the forest understory. Undamaged seedlings survived better and showed a slightly higher growth rate in the sun. Whereas simulated herbivory in the shade decreased seedling survival and growth by 34% and 19%, respectively, damaged and undamaged seedlings showed similar survival and growth in the sun. Leaf tissue lost to herbivores in the shade appears to be too expensive to replace under the limiting light conditions of forest understory. Following evaluations of herbivore abundance and plant resistance and tolerance in contrasting light environments, we have shown how herbivory on a light-demanding tree species may contribute to its exclusion from shade sites. Thus, in the shaded forest understory, where the seedlings of some tree species are close to their physiological tolerance limit, herbivory could play an important role in plant establishment. PMID:20628638

Salgado-Luarte, Cristian; Gianoli, Ernesto

2010-01-01

389

Leaf Water Potential, Stomatal Resistance, and Photosynthetic Response to Water Stress in Peach Seedlings 1  

PubMed Central

Individual groups of peach (Prunus persica [L.] Batsch) seedlings stressed to ?17, ?26 and ?36 bars recovered to control levels within 1, 3, and 4 days, respectively. Stomatal resistance was significantly correlated with both leaf water potential and net photosynthesis. In seedlings stressed to ?52 bars, leaf water potential and stomatal resistance recovered sooner than net photosynthesis, despite recovery of 02 evolution at a rate similar to leaf water potential. Therefore, some nonstomatal factor other than reduction in photochemical activity must be responsible for the lag in recovery of CO2 assimilation following irrigation.

Hand, J. Mark; Young, Eric; Vasconcelos, Aurea C.

1982-01-01

390

Photosynthetic assimilation and carbohydrate allocation of Quercus rubra seedlings in response to simulated herbivory  

Microsoft Academic Search

Introduction  The artificial regeneration of oaks (Quercus spp.) can supplement deficient natural regeneration, yet growth and physiology of newly planted seedlings are often negatively\\u000a affected by animal herbivory. Alternative nursery stock types with improved stress resistance may help improve regeneration\\u000a success.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and method  1-year-old bare-root (1+0) and container (164 mL) northern red oak (Quercus rubra L.) seedlings were transplanted into pots, subjected

Phillip O. Woolery; Douglass F. Jacobs

2011-01-01

391

Specificity between Neotropical tree seedlings and their fungal mutualists leads to plant-soil feedback.  

PubMed

A growing body of evidence obtained largely from temperate grassland studies suggests that feedbacks occurring between plants and their associated soil biota are important to plant community assemblage. However, few studies have examined the importance of soil organisms in driving plant-soil feedbacks in forested systems. In a tropical forest in central Panama, we examined whether interactions between tree seedlings and their associated arbuscular mycorrhizal fungi (AMF) lead to plant-soil feedback. Specifically, do tropical seedlings modify their own AMF communities in a manner that either favors or inhibits the next cohort of conspecific seedlings (i.e., positive or negative feedback, respectively)? Seedlings of two shade-tolerant tree species (Eugenia nesiotica, Virola surinamensis) and two pioneer tree species (Luehea seemannii, Apeiba aspera) were grown in pots containing identical AMF communities composed of equal amounts of inoculum of six co-occurring AMF species. The different AMF-host combinations were all exposed to two light levels. Under low light (2% PAR), only two of the six AMF species sporulated, and we found that host identity did not influence composition of AMF spore communities. However, relative abundances of three of the four AMF species that produced spores were influenced by host identity when grown under high light (20% PAR). Furthermore, spores of one of the AMF species, Glomus geosporum, were common in soils of Luehea and Eugenia but absent in soils of Apeiba and Virola. We then conducted a reciprocal experiment to test whether AMF communities previously modified by Luehea and Apeiba differentially affected the growth of conspecific and heterospecific seedlings. Luehea seedling growth did not differ between soils containing AMF communities modified by Luehea and Apeiba. However, Apeiba seedlings were significantly larger when grown with Apeiba-modified AMF communities, as compared to Apeiba seedlings grown with Luehea-modifed AMF communities. Our experiments suggest that interactions between tropical trees and their associated AMF are species-specific and that these interactions may shape both tree and AMF communities through plant-soil feedback. PMID:20957954

Mangan, Scott A; Herre, Edward A; Bever, James D

2010-09-01

392

On Methods of Isolation of Active, Tightly Coupled Mitochondria of Wheat Seedlings 1  

PubMed Central

Tightly coupled mitochondria can be isolated from wheat seedlings 1) if young seedlings are used, 2) if the grinding medium is buffered and contains bovine serum albumin (BSA), 3) if the isolation procedure, including centrifugation is 10 to 11 minutes long. Mitochondria isolated in this manner oxidize ?-ketoglutarate, malate and NADH. Respiratory control (R.C.) values are around 6, 3, and 10, respectively. ADP:O values with those substrates are 4.0, 2.9, and 1.7, respectively. Mitochondria are stable for 3 hours. It is suggested that the technique may be used for preparation of mitochondria for comparative studies since activities of these mitochondria are highly reproducible.

Sarkissian, Igor V.; Srivastava, Hari K.

1968-01-01

393

Effects of simulated acid rain on seedling emergence and growth of five broad-leaved species  

Microsoft Academic Search

Seeds and seedlings of five broad-leaved species were separately exposed to simulated acid rain at pH values of 2.0, 3.5,\\u000a 5.0, and 6.0, or to distilled water (the control). The results showed that seed germination was remarkably inhibited by pH\\u000a 2.0 treatment for three species. Significant foliar damage, decline in chlorophyll contents, and retardation of the seedlings\\u000a growth of all

Fan Houbao; Li Chuanrong

1999-01-01

394

Effects of temperature on growth and water relations of cacao ( Theobroma cacao var. Comum ) seedlings  

Microsoft Academic Search

Growth of 55-day-oldTheobroma cacao var.Comum seedlings varied with temperature regimes, various plant parts, growth parameters, and time of harvesting. Over a 60-day\\u000a period the optimal day-temperature regimes were near 33.3C for dry weight increase and relative growth rates of seedlings\\u000a and leaves; 30.5C for increase in leaf area, height growth, and leaf abscission; 22.2C for dry weight increase of stems

A. R. Sena Gomes; T. T. Kozlowski

1987-01-01

395

Analysis of vegetable seedlings grown in contact with Apollo 14 lunar surface fines.  

NASA Technical Reports Server (NTRS)

Study of plant seedlings treated with lunar material, grown for 14 to 21 days, and then subjected to chemical analyses and other measurements. The purpose of the study was to determine whether plants growing in contact with lunar-surface fines contained a different elemental composition compared with untreated seedlings. The results indicate a direct interaction between germfree plants and lunar material. Treated plants dissolved and absorbed significant quantities of Al, Fe, and Ti from the lunar fines. Cabbage and Brussel sprouts were particularly efficient in the dissolution and absorption of Mn.

Walkinshaw, C. H.; Johnson, P. H.

1971-01-01

396

Responses of plant seedlings to hypergravity: cellular and molecular aspects  

NASA Astrophysics Data System (ADS)

Hypergravity produced by centrifugation has been used to analyze the responses of plant seedlings to gravity stimulus. Elongation growth of stem organs is suppressed by hypergravity, which can be recognized as a way for plants to resist gravitational force. The mechanisms inducing growth suppression under hypergravity conditions were analyzed at cellular and molecular levels. When growth was suppressed by hypergravity, a decrease in the cell wall extensibility was brought about in various plants. Hypergravity also induced a cell wall thickening and an increase in the molecular mass of the certain hemicellulosic polysaccharides. Both a decrease in the activities hydrolyzing such polysaccharides and an increase in the apoplast pH were involved in such changes in the cell wall constituents. Thus, the cell wall metabolism is greatly modified under hypergravity conditions, which causes a decrease in the cell wall extensibility, thereby inhibiting elongation growth in stem organs. On the other hand, to identify genes involved in hypergravity-induced growth suppression, changes in gene expression by hypergravity treatment were analyzed in Arabidopsis hypocotyls by differential display method. Sixty-two genes were expressed differentially: expression levels of 39 genes increased, whereas those of 23 genes decreased under hypergravity conditions. The expression of these genes was further analyzed using RT-PCR. One of genes upregulated by hypergravity encoded hydroxymethylglutaryl-CoA reductase (HMGR), which catalyzes a reaction producing mevalonic acid, a key precursor of hormones such as gibberellic acid and abscisic acid. The expression of HMGR gene increased within several hours after hypergravity treatment. Also, compactin, an inhibitor of HMGR activity, prevented hypergravity-induced growth suppression, suggesting that HMGR is involved in suppression of Arabidopsis hypocotyl growth by hypergravity. In addition, hypergravity increased the expression levels of CCR1 and ERD15, which were shown to take part in the signaling pathway of environmental stimuli such as temperature and water. These cellular and molecular changes appear to be involved in a series of events leading to growth suppression of stem organs under hypergravity conditions.

Hoson, T.; Yoshioka, R.; Soga, K.; Wakabayashi, K.; Takeba, G.

397

Effects of Kinetin, IAA, and Gibberellin on Ethylene Production, and Their Interactions in Growth of Seedlings 12  

PubMed Central

Kinetin in concentrations of 10?8 to 10?4 m, stimulated ethylene production in 3 and 4-day old etiolated seedlings of Alaska pea (Pisum sativum L. var. Alaska). Seedlings of other species responded similarly. The response to kinetin depended on the age of the seedlings. Kinetin alone did not influence ethylene production in 6-day old stem sections, but it greatly increased the enhancing effect of IAA. Gibberellic acid had no effect on ethylene production by pea seedlings during the first 6 days of growth. Ethylene and gibberellic acid are antagonistic in their effects on growth of the seedlings; ethylene interfered severely with the action of gibberellic acid but did not completely suppress it. The inhibitors cycloheximide, cupferron, and N-ethylmaleimide, caused considerable inhibition of kinetin-induced ethylene production but were much less effective in the endogenous ethylene-forming system.

Fuchs, Yoram; Lieberman, Morris

1968-01-01

398

Early growth of Quercus castaneifolia (C.A. Meyer) seedlings as affected by weeding, shading and irrigation.  

PubMed

The influence of shading, irrigation and weeding on survival, growth and morphology of 1-year Quercus castaneifolia seedlings was studied in north of Iran. The seedlings were grown under eight treatments including full-light versus artificial shading, irrigation versus non-irrigation and weed presence versus weed removing at three replicates. At the end of the first growing season seedling survival in all treatments was 100%. Weed removing had positive effect on height, diameter growth, slenderness coefficient and leaf area of Q. castaneifolia. Irrigation enhanced diameter growth and leaf area and shading increased leaf area. Irrigation had no significant effect on plant growth where the weed was removed. In weed plots seedlings growth and leaf area were greater in shading than in full-light. The results indicated that for 1 year Q. castaneifolia seedlings, weeding, in contrast to irrigation, is an essential factor. Where the weed competition is a difficulty, plantation with higher stem length should be applied. PMID:19070109

Mirzaei, Javad; Tabari, Masoud; Daroodi, Hadi

2007-08-01

399

Source-sink regulation of cotyledonary reserve mobilization during cashew (Anacardium occidentale) seedling establishment under NaCl salinity.  

PubMed

Seedling establishment is a critical process to crop productivity, especially under saline conditions. This work was carried out to investigate the hypothesis that reserve mobilization is coordinated with salt-induced inhibition of seedling growth due to changes in source-sink relations. To test this hypothesis, cashew nuts (Anacardium occidentale) were sown in vermiculite irrigated daily with distilled water (control) or 50mM NaCl and they were evaluated at discrete developmental stages from the seed germination until the whole seedling establishment. The salt treatment coordinately delayed the seedling growth and the cotyledonary reserve mobilization. However, these effects were more pronounced at late seedling establishment than in earlier stages. The storage protein mobilization was affected by salt stress before the lipid and starch breakdown. The globulin fraction represented the most important storage proteins of cashew cotyledons, and its mobilization was markedly delayed by NaCl along the seedling establishment. Free amino acids were mostly retained in the cotyledons of salt-treated seedlings when the mobilization of storage proteins, lipids and starch was strongly delayed. Proline was not considerably accumulated in the cotyledons of cashew seedlings as a response to NaCl salinity. According to these results it is noteworthy that the salt-induced inhibition of seedling growth is narrowly coordinated with the delay of reserve mobilization and the accumulation of hydrolysis products in cotyledons. Also, it was evidenced that free amino acids, especially those related to nitrogen transport, are potential signals involved in the regulation of storage protein hydrolysis during cashew seedling establishment under NaCl salinity. PMID:18448194

Voigt, Eduardo Luiz; Almeida, Tânia Dias; Chagas, Roberta Magalhăes; Ponte, Luiz Ferreira Aguiar; Viégas, Ricardo Almeida; Silveira, Joaquim Albenísio Gomes

2009-01-01

400

Leaf life span spectrum of tropical woody seedlings: effects of light and ontogeny and consequences for survival  

PubMed Central

Background and Aims Leaf life span is widely recognized as a key life history trait associated with herbivory resistance, but rigorous comparative data are rare for seedlings. The goal of this study was to examine how light environment affects leaf life span, and how ontogenetic development during the first year may influence leaf fracture toughness, lamina density and stem density that are relevant for herbivory resistance, leaf life span and seedling survival. Methods Data from three experiments encompassing 104 neotropical woody species were combined. Leaf life span, lamina and vein fracture toughness, leaf and stem tissue density and seedling survival were quantified for the first-year seedlings at standardized ontogenetic stages in shade houses and common gardens established in gaps and shaded understorey in a moist tropical forest in Panama. Mortality of naturally recruited seedlings till 1 year later was quantified in 800 1-m2 plots from 1994 to 2011. Key Results Median leaf life span ranged widely among species, always greater in shade (ranging from 151 to >1790 d in the understorey and shade houses) than in gaps (115–867 d), but with strong correlation between gaps and shade. Leaf and stem tissue density increased with seedling age, whereas leaf fracture toughness showed only a weak increase. All these traits were positively correlated with leaf life span. Leaf life span and stem density were negatively correlated with seedling mortality in shade, while gap mortality showed no correlation with these traits. Conclusions The wide spectrum of leaf life span and associated functional traits reflects variation in shade tolerance of first-year seedlings among coexisting trees, shrubs and lianas in this neotropical forest. High leaf tissue density is important in enhancing leaf toughness, a known physical defence, and leaf life span. Both seedling leaf life span and stem density should be considered as key functional traits that contribute to seedling survival in tropical forest understoreys.

Kitajima, Kaoru; Cordero, Roberto A.; Wright, S. Joseph

2013-01-01

401

Effects of Increased Nitrogen Deposition and Precipitation on Seed and Seedling Production of Potentilla tanacetifolia in a Temperate Steppe Ecosystem  

PubMed Central

Background The responses of plant seeds and seedlings to changing atmospheric nitrogen (N) deposition and precipitation regimes determine plant population dynamics and community composition under global change. Methodology/Principal Findings In a temperate steppe in northern China, seeds of P. tanacetifolia were collected from a field-based experiment with N addition and increased precipitation to measure changes in their traits (production, mass, germination). Seedlings germinated from those seeds were grown in a greenhouse to examine the effects of improved N and water availability in maternal and offspring environments on seedling growth. Maternal N-addition stimulated seed production, but it suppressed seed mass, germination rate and seedling biomass of P. tanacetifolia. Maternal N-addition also enhanced responses of seedlings to N and water addition in the offspring environment. Maternal increased-precipitation stimulated seed production, but it had no effect on seed mass and germination rate. Maternal increased-precipitation enhanced seedling growth when grown under similar conditions, whereas seedling responses to offspring N- and water-addition were suppressed by maternal increased-precipitation. Both offspring N-addition and increased-precipitation stimulated growth of seedlings germinated from seeds collected from the maternal control environment without either N or water addition. Our observations indicate that both maternal and offspring environments can influence seedling growth of P. tanacetifolia with consequent impacts on the future population dynamics of this species in the study area. Conclusion/Significance The findings highlight the importance of the maternal effects on seed and seedling production as well as responses of offspring to changing environmental drivers in mechanistic understanding and projecting of plant population dynamics under global change.

Li, Yang; Yang, Haijun; Xia, Jianyang; Zhang, Wenhao; Wan, Shiqiang; Li, Linghao

2011-01-01

402

Selective depredation of planted hardwood seedlings by wild pigs in a wetland restoration area.  

National Technical Information Service (NTIS)

Following the planting of several thousand hardwood seedlings in a 69-ha wetland restoration area in west-central South Carolina, wild pigs (Sus scrofa) depredated a large percentage of the young trees. This planting was undertaken as part of a mitigation...

J. J. Mayer

1999-01-01

403

Seedling Recruitment in a Native Tree Plantation in the Lowland Tropical Rainforests of Costa Rica  

Microsoft Academic Search

In a continuation of a preexisting reforestation project, we examined the recruitment of seedlings in plantation plots of varying light (shade vs. sun) and cultivation (monoculture vs. polyculture), in the lowland tropical rainforest of Costa Rica. The treatment plots primarily had canopies of Pentaclethera macroloba (Fabacae), the most common tree in the area, planted in a 3x3 meter grid. However,

Joseph Statwick

2007-01-01

404

Citrus Seedling Growth and Susceptibility to Root Rot as Affected by Phosphite and Phosphate  

Microsoft Academic Search

The growth of 'Ridge Pineapple' sweet orange (Citrus sinensis (L.) Osbeck) seedlings and their susceptibility to Phytophthora root rot were studied under contrasting supplies of phosphate (Pi) or Phosphite (Phi). After 10 weeks of repeated applications of nutri- ent solutions, Phi concentrations were barely detectable in soil. Soil Pi was higher in Phi treatments than in pots that received Pi

Vladimir Orbovic; James P. Syvertsen; Diane Bright; Deborah L. Van Clief; James H. Graham

2008-01-01

405

Nitrogen availability to citrus seedlings from urea and from mineralization of citrus leaf or compost  

Microsoft Academic Search

A pot experiment was conducted using a Candler fine sand (hyperthermic, uncoated, Typic Quartzipsamments) amended with either citrus leaves or compost, to measure the nitrogen (N) mineralization and its availability to two citrus rootstock seedlings. A rapid increase in NH4?N concentration was evident in the soil amended with citrus leaves as compared to compost during the initial 14 to 20

H. Dou; A. K. Alva

1998-01-01

406

Physical and Chemical Properties of Substrates to Cultivate Seedling of Citrus Rootstocks  

Microsoft Academic Search

An experiment was carried out to assess the physical and chemical evolution of three substrates and their relation to the vegetative development of seedlings of citrus rootstock, cultivated in containers. The experiment was carried out in greenhouse conditions on 27 September 2001 and continued until 120 days after sowing. The experimental design was randomized block in a split?plot scheme. In

Gilmar Schäfer; Paulo Vitor Dutra de Souza; Otto Carlos Koller; Sérgio Francisco Schwarz

2008-01-01

407

Comparative drought-resistance of seedlings of 28 species of co-occurring tropical woody plants  

Microsoft Academic Search

Quantifying plant drought resistance is important for understanding plant species' association to microhabitats with different soil moisture availability and their distribution along rainfall gradients, as well as for understanding the role of underlying morphological and physiological mechanisms. The effect of dry season drought on survival and leaf-area change of first year seedlings of 28 species of co-occurring woody tropical plants

Bettina M. J. Engelbrecht; Thomas A. Kursar

2003-01-01

408

The use of seedling leaf death score for evaluation of drought resistance of rice  

Microsoft Academic Search

Leaf death (drought score) of seedlings has been extensively used in rice breeding programs as a selection index for drought resistance. This paper investigates the factors that affect the drought score of rice cultivars exposed to water stress during the vegetative stage and the relationship between drought score and yield. Two upland experiments consisting of 21 and 8 cultivars, respectively,

J. H. Mitchell; D. Siamhan; M. H. Wamala; J. B. Risimeri; E. Chinyamakobvu; S. A. Henderson; S. Fukai

1998-01-01

409

Anatomy of seedling tap roots of loblolly pine ( Pinus taeda L.)  

Microsoft Academic Search

The development of tap root anatomical features was investigated in seedlings of loblolly pine (Pinus taeda L.) under both pot and pouch growth regimes. The roots possessed the three anatomical zones previously observed in jack pine (Pinus banksiana Lamb) and Eucalyptus pilularis Sm. - white, condensed tannin (CT), and cork - suggesting that this developmental sequence is preserved over species

Daryl E. Enstone; Carol A. Peterson; Stephen W. Hallgren

2001-01-01

410

Screening selected genotypes of cowpea [Vigna unguiculata (L.) Walp.] for salt tolerance during seedling growth stage.  

PubMed

The environmental stress such as, salinity (soil or water) are serious obstacles for field crops especially in the arid and semi-arid parts of the world. This study was conducted to assess the potential for salt tolerance of cowpea genotypes during the seedling stage. The experimental treatments were 9 cowpea genotypes and 4 NaCl concentrations (0, 50, 100 and 200 mM) and they were tested in greenhouse. The experimental design was completely randomized design in factorial combination with three replications. Data analysis was carried out using SAS (version 9.1) statistical software. Seedling shoots and root traits, seedling shoots and root weight, number of leaves and total biological yield were evaluated. The analyzed data revealed highly significant (p < 0.001) variation among cowpea genotypes, treatments and their interactions. It is found that salt stress significantly decreased root length, shoot length, seedling shoot and root weight of cowpea genotypes. The extent of decrease varied with genotypes and salt concentrations. Most genotypes were highly susceptible to 200 mM NaCl concentration. The correlation analysis revealed positive and significant association among most of the parameters. Genotypes 210856, 211557 and Asebot were better salt tolerant. The study revealed the presence of broad intra specific genetic variation in cowpea varieties for salt stress with respect to their early biomass production. PMID:24505992

Gogile, A; Andargie, M; Muthuswamy, M

2013-07-15

411

Regulation of the Accumulation and Reduction of Nitrate by Nitrogen and Carbon Metabolites in Maize Seedlings  

Microsoft Academic Search

lhe accumulation and reduction of nitrate in the presence of the nitrogen metabolites asparagine (Asn) and glutamine (Cln) and the carbon metabolite sucrose (Suc) were examined in maize (Zea mays L.) seedlings in an attempt to separate their effects on the nitrate uptake system and the nitrate reduction system. After 8 h of expo- sure to nitrate in the presence

Sobhana Sivasankar; Steven Rothstein; Ann Oaks

412

Interactive effects of substrate, hydroperiod, and nutrients on seedling growth of Salix nigra and Taxodium distichum  

USGS Publications Warehouse

The large river swamps of Louisiana have complex topography and hydrology, characterized by black willow (Salix nigra) dominance on accreting alluvial sediments and vast areas of baldcypress (Taxodium distichum) deepwater swamps with highly organic substrates. Seedling survival of these two wetland tree species is influenced by their growth rate in relation to the height and duration of annual flooding in riverine environments. This study examines the interactive effects of substrate, hydroperiod, and nutrients on growth rates of black willow and baldcypress seedlings. In a greenhouse experiment with a split-split-plot design, 1-year seedlings of black willow and baldcypress were subjected to two nutrient treatments (unfertilized versus fertilized), two hydroperiods (continuously flooded versus twice daily flooding/draining), and two substrates (sand versus commercial peat mix). Response variables included height, diameter, lateral branch count, biomass, and root:stem ratio. Black willow growth in height and diameter, as well as all biomass components, were significantly greater in peat substrate than in sand. Black willow showed a significant hydroperiod-nutrient interaction wherein fertilizer increased stem and root biomass under drained conditions, but flooded plants did not respond to fertilization. Baldcypress diameter and root biomass were higher in peat than in sand, and the same two variables increased with fertilization in flooded as well as drained treatments. These results can be used in Louisiana wetland forest models as inputs of seedling growth and survival, regeneration potential, and biomass accumulation rates of black willow and baldcypress.

Day, R. H.; Doyle, T. W.; Draugelis-Dale, R. O.

2006-01-01

413

Effect on isoflavone of soybean seedlings by 532nm laser irradiation  

NASA Astrophysics Data System (ADS)

We took soybeans as experimental substance to study how the 532nm laser with different power density and irradiation time affected the pullulation ratio of the soybeans, average height of seedlings and the isoflavone content of seedlings' cotyledon and laminae. The mechanism that laser pretreatment of soybean seeds could increase the isoflavone content of the seedlings was discussed in such both aspects as the efficiency of the photosynthesis and the activity of a phenylalanine ammonia-lyase (PAL) as an initial enzyme for synthesizing the isoflavone. The results showed that after the soybean seeds were pretreated by laser, the activity of the PAL and the resultants of the photosynthesis such as the sugar of dissolubility, the sucrose, and the amylum all increased with the soybean seeds irradiated by laser in which the effect on the soybean seeds pretreated by 15mW/mm2 laser for 5 min was the most obvious. As a result, the photosynthesis efficiency of the soybean seedlings increased after being pretreated by laser, which might offer the foundation for accumulating a large amount of isoflavone.

Tian, J.; Jin, L. H.; Li, J. M.; Shen, B. J.; Wang, C. Y.; Lu, X.; Zhao, X. L.

2009-10-01

414

Mechanism of improved phosphate uptake efficiency in banana seedlings on acidic soils using fertigation  

Microsoft Academic Search

Fertigation improves nutrient uptake efficiency greatly, while the mechanism of increased nutrient uptake efficiency remains unclear. In this study, the effects of conventional phosphate (P) fertilization (by mixing fertilizer with soils) and fertigation (by dissolving fertilizer in water) on P uptake were compared in banana (Musa sapientum) seedlings. Results indicated that, compared with conventional fertilization, fertigation increased the concentration of

N. Pan; H. Shen; D. M. Wu; L. S. Deng; P. F. Tu; H. H. Gan; Y. C. Liang

2011-01-01

415

Role of Carotenoids in the Phototropic Response of Corn Seedlings 1  

PubMed Central

The herbicide, 4 chloro-5-(methylamino)-2-(?,?,?,-trifluoro-m-tolyl)-3 (2H)-pyridazinone (SAN 9789), which blocks the synthesis in higher plants of colored carotenoids but not of flavins, was used to examine the involvement of carotenoids in corn seedling phototropism. It was concluded that “bulk” carotenoids are not the photoreceptor pigment based on the results that increasing concentrations of SAN 9789 (up to 100 micromolar) did not alter the phototropic sensitivity to 380 nanometers light (using geotropism as a control) and did not increase the threshold intensities of fluence response curves for both 380 and 450 nanometers light even though carotenoid content was reduced to 1 to 2% of normal. SAN 9789 treatment, however, did reduce seedling sensitivity toward 450 nanometers light indicating that carotenoids are involved in phototropism. Carotenoids, which are located mainly in the primary leaves, may act in phototropism as an internal screen, enhancing the light intensity gradient across the seedling and thus contributing to the ability of the seedling to perceive light direction. These results indicate that the action spectra for phototropic responses can be significantly affected by the absorbance of screening pigments in vivo thus altering its shape from the in vitro absorption spectrum of the photoreceptor pigment.

Vierstra, Richard D.; Poff, Kenneth L.

1981-01-01

416

EMERGENCE AND MORTALITY OF SEEDLINGS IN SOME APPLE (Malus?domestica Borkh.) PROGENIES  

Microsoft Academic Search

A B S T R A C T The experiment was conducted on 58 apple hybrid families in the period 2004- 2006. The seeds for germination were prepared by stratification in whole fruits and subsequently by a complementary treatment in a peat substrate in multipots for 43 to 92 days. Seedling emergences were on average over 95% in each year.

Cezary Piestrzeniewicz; Janusz Andziak; Ewa Andziak

417

Effects of Salinity and Temperature on Germination and Seedling Establishment of Sweet Basil (Ocimum basilicum L.)  

Microsoft Academic Search

Sweet basil (Ocimum basilicum L.) is usually propagated from seed, but establishment of the plant is sometimes difficult as seed germination and seedling emergence may be limited under saline and unfavorable temperature conditions. In this study, salt and temperature tolerance of green and purple types of basil were investigated by subjecting both green and purple basil to selected levels of

A. A. Ramin

2006-01-01

418

Plant SILAC: Stable-Isotope Labelling with Amino Acids of Arabidopsis Seedlings for Quantitative Proteomics  

PubMed Central

Stable Isotope Labelling by Amino acids in Cell culture (SILAC) is a powerful technique for comparative quantitative proteomics, which has recently been applied to a number of different eukaryotic organisms. Inefficient incorporation of labelled amino acids in cell cultures of Arabidopsis thaliana has led to very limited use of SILAC in plant systems. We present a method allowing, for the first time, efficient labelling with stable isotope-containing arginine and lysine of whole Arabidopsis seedlings. To illustrate the utility of this method, we have combined the high labelling efficiency (>95%) with quantitative proteomics analyses of seedlings exposed to increased salt concentration. In plants treated for 7 days with 80 mM NaCl, a relatively mild salt stress, 215 proteins were identified whose expression levels changed significantly compared to untreated seedling controls. The 92 up-regulated proteins included proteins involved in abiotic stress responses and photosynthesis, while the 123 down-regulated proteins were enriched in proteins involved in reduction of oxidative stress and other stress responses, respectively. Efficient labelling of whole Arabidopsis seedlings by this modified SILAC method opens new opportunities to exploit the genetic resources of Arabidopsis and analyse the impact of mutations on quantitative protein dynamics in vivo.

Lewandowska, Dominika; ten Have, Sara; Hodge, Kelly; Tillemans, Vinciane; Lamond, Angus I.; Brown, John W. S.

2013-01-01

419

Do isolated gallery-forest trees facilitate recruitment of forest seedlings and saplings in savannna?  

NASA Astrophysics Data System (ADS)

Facilitation is an ecological process that allows some species to establish in environments they can hardly afford in the absence of the process. This study investigated if the subcanopy of gallery-forest trees isolated in savanna is suitable for the early recruitment of forest woody species. We measured tree crown area as well as the density of seedlings and saplings of gallery-forest tree species beneath isolated trees and in the savanna matrix along 50 transects of 5-km long and 600 m wide located along four gallery forests. We then tested the nurse-plant effect and Janzen-Connell hypothesis beneath isolated trees. We also examined the relationships between the crown area and the density of seedlings and saplings. Among the eight identified tree species isolated in savanna, only Daniellia oliveri and Khaya senegalensis showed nurse-plant effect and promoted a significant, yet low early recruitment with a seedling-to-sapling survival of 0.044 and 0.578, respectively. The suitability of the subcanopy of isolated trees decreased with the recruitment progression and Janzen-Connell effects were absent. Seedlings had neutral association with the crown area of isolated trees which shifted to positive at the sapling stage. The species of the isolated tree and the crown area explained less than 20% of total variance, indicating that other predictive factors are important in explaining the nurse-plant effect observed in this study.

Azihou, Akomian Fortuné; Glčlč Kakaď, Romain; Sinsin, Brice

2013-11-01

420

BLH1 and KNAT3 modulate ABA responses during germination and early seedling development in Arabidopsis.  

PubMed

The signal transduction pathway governed by the phytohormone abscisic acid (ABA) regulates not only abiotic stress responses but also early developmental programs such as seed dormancy, germination and seedling growth in response to environmental signals. Optimal plant growth and development depend on the integration of environmental stimuli and intrinsic developmental programs. Here, we show that the homeodomain transcription factors BLH1 and KNAT3, previously implicated in embryo sac development, have additional functions in ABA-mediated seed dormancy and early seedling development. The ABA-dependent induction of BLH1 and KNAT3 expression required the presence of functional PYR/PYL/RCAR receptors. The blh1 and knat3 mutants were less sensitive than the wild-type to ABA or salinity exposure during seed germination and early seedling development. In contrast, BLH1 over-expressing lines were hypersensitive to ABA and salinity, and exhibited increased expression of ABA-responsive genes, such as ABI3 and ABI5. BLH1 interacted with KNAT3 and enhanced the retention of KNAT3 in the nucleus. BLH1 and KNAT3 synergistically increased the ABA responses by binding to and subsequently activating the ABI3 promoter. Taken together, we propose that BLH1 and KNAT3 together modulate seed germination and early seedling development by directly regulating ABI3 expression. PMID:23663178

Kim, Dachan; Cho, Young-Hyun; Ryu, Hojin; Kim, Yoonhee; Kim, Tae-Houn; Hwang, Ildoo

2013-09-01

421

Tolerance of Peltophorum pterocarpum D. C. Baker Ex K. Heyne Seedlings to Lead and Cadmium Treatment  

Microsoft Academic Search

Trace metals present in the environment are hazardous to ecological systems and also to human health and plant growth. In this study, lead and cadmium treatments affected the growth indices of Peltophorum pterocarpum. Lead treatment at 25-100 ppm produced significant (p < 0.05) effects on seedling dry weight of P. pterocarpum as compared with control. Root growth was significantly (p

Muhammad Shafiq; Muhammad Zafar Iqbal

2006-01-01

422

Kinetics of wound-induced hydraulic signals and variation potentials in wheat seedlings  

Microsoft Academic Search

Displacement transducers were used to demonstrate that localised wounding causes a rapid and systemic increase in leaf thickness in seedlings of wheat (Triticum durum Desf. cv. Iva). These increases are interpreted as reflecting wound-induced hydraulic signals. The duration of the wound-induced increase was found to be about 1 h or more, and it was shown that repeated wounds could induce

M. Malone; HRI Wellesbourne; Warwicks CV

1992-01-01

423

Characterization of Cadmium Binding, Uptake, and Translocation in Intact Seedlings of Bread and Durum Wheat Cultivars  

Microsoft Academic Search

High Cd content in durum wheat (Triticum turgidum L. var durum) grain grown in the United States and Canada presents potential health and economic problems for consumers and grow- ers. In an effort to understand the biological processes that result in excess Cd accumulation, root Cd uptake and xylem translocation to shoots in seedlings of bread wheat (Triticum aestivum L.)

Jonathan J. Hart; Ross M. Welch; Wendell A. Norvell; Lori A. Sullivan; Leon V. Kochian

1998-01-01

424

Induction of Heat Stress Tolerance in Barley Seedlings by Pre-Sowing Seed Treatment with Glycinebetaine  

Microsoft Academic Search

Heat stress adversely affects plant growth and development, while glycinebetaine (GB) plays a protective role under stressful conditions. The objective of this study was to assess the optimum level of GB for use as a presowing seed treatment and the subsequent effect on the heat tolerance of barley (Hordeum vulgare L. cv. Haider-93) seedlings. Among a range of GB levels,

Abdul Wahid; Asma Shabbir

2005-01-01

425

Seedling growth and survival of selected wild edible fruit species of the Sikkim Himalaya, India  

Microsoft Academic Search

In the Sikkim Himalaya, an enormous variety of wild growing plants are exploited at large scale for collection of their edible parts, of which six most prominently utilized fruit species (viz., Baccaurea sapida, Diploknema butyracea, Elaeagnus latifolia, Eriolobus indica, Machilus edulis and Spondias axillaris) were investigated. The growth of nursery raised seedlings was measured at 3 month intervals until two years

Manju Sundriyal; R. C. Sundriyal

2005-01-01

426

Efficiency of yeast in enhancement of the oxidative defense system in salt-stressed flax seedlings.  

PubMed

The combined effects of yeast (1 ppm) and salinity on germination, seedling growth, metabolite accumulation and antioxidant defense system of flax (Linum usitatissimum) seeds grown at 100, 200 and 300 mM NaCl were studied. In this investigation, the germination was completely inhibited at 300 mM NaCl. Moreover, salinity induced marked increases in lipid peroxidation product (MDA), soluble carbohydrates as well as the reduced glutathione which were concomitant with sharp decrease in total phenols and ascorbic acid contents in 12-day-old flax seedlings. Furthermore, NaCl treatments increased the activities of some antioxidant enzymes (superoxide dismutase; SOD, peroxidase; POX and polyphenol oxidase; PPO). On the other hand, yeast treatments under salinity stress restored the membrane integrity and improved seedling growth. The results suggested that yeast treatments mitigated salinity stress via accumulation of some osmoprotectants such as free amino acids particularly proline which associated with elevating the defense system in terms of ascorbic acid, glutathione and total phenol contents. Yeast treatments also stimulated the activities of some antioxidant enzymes, preventing membrane peroxidation resulting in high capacity for germination and improved seedling growth under sever salt stress. PMID:23567836

Emam, M M

2013-03-01

427

Morphogenetic responses from in vitro cultured seedling explants of mung bean (Vigna radiata L. Wilczek)  

Microsoft Academic Search

The morphogenetic responses of seedling explants of mung bean (Vigna radiata L. Wilczek cv ML-5) were studied in vitro. Direct induction of shoots\\/plants was possible from shoot tip, cotyledon and cotyledonary node explants. Dedifferentiation of the explants viz; Shoot tip, cotyledons, cotyledonary node, primordial leaves and roots was obtained on basal medium supplemented with auxin and cytokinin. Shoot regeneration was

Helena Mathews

1987-01-01

428

Limiting Populations and Spread of Clavibacter michiganensis subsp. michiganensis on Seedling Tomatoes in the Greenhouse  

Microsoft Academic Search

Werner, N. A., Fulbright, D. W., Podolsky, R., Bell, J., and Hausbeck, M. K. 2002. Limiting populations and spread of Clavibacter michiganensis subsp. michiganensis on seedling toma- toes in the greenhouse. Plant Dis. 86:535-542. Symptomless greenhouse tomato transplants may harbor high populations of Clavibacter michi- ganensis subsp. michiganensis, the causal agent of bacterial canker, leading to yield loss in the

N. A. Werner; D. W. Fulbright; R. Podolsky; J. Bell; M. K. Hausbeck

2002-01-01