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Sample records for cinnamomum camphora seedlings

  1. [Effects of NO2 on Cinnamomum camphora seedlings growth and photosynthesis].

    PubMed

    Zhuo, Chen-Mei; Chen, Ying-Xu; Du, Guo-Jian

    2009-07-01

    A 2-month fumigation experiment was conducted with opened top chambers to study the effects of different concentration (0.1, 0.5, and 4.0 microl x L(-1)) NO2 on the growth and photosynthesis of 1-year Cinnamomum camphora seedlings. Fumigation with 0.1 and 0.5 microl NO2 x L(-1) promoted the growth of the seedlings, while with 4.0 microl NO2 x L(-1) was in adverse. The diurnal variation of net photosynthetic rate (P(n)) presented two-peaks, with an obvious depression in midday. 0.5 microl NO2 x L(-1) increased the P(n), the maximum of P(n) reached 8.542 micromol CO2 x m(-2) s(-1); 4.0 microl NO2 x L(-1) decreased the P(n) in most period of time; while the effect of 0.1 microl NO2 x L(-1) varied with time period. Fumigation with 0.5 and 4.0 microl NO2 x L(-1) increased the maximal and minimal values of stomatal conductance (G(s)) and intercellular CO2 concentration (C( i)), while 0.1 microl NO2 x L(-1) increased the maximal and minimal values of C(i) but decreased the maximal and minimal values of G(s). At the middle and late stages of fumigation, the mean P(n) of the seedlings treated with 0.5 microl NO2 x L(-1) was significantly higher than that treated with 0.1 and 4 microl NO2 x L(-1). At the early stage of fumigation, 0.5 and 4.0 micro NO2 x L(-1) significantly decreased the maximal PS II efficiency (F(v)/F(m)); and at the late stage, 4.0 microl NO2 x L(-1) still decreased the F(v)/F(m) significantly. PMID:19899466

  2. Effects of 60-day NO2 fumigation on growth, oxidative stress and antioxidative response in Cinnamomum camphora seedlings*

    PubMed Central

    Chen, Zhuo-mei; Chen, Ying-xu; Du, Guo-jian; Wu, Xi-lin; Li, Feng

    2010-01-01

    Objective: To study the oxidative stress and antioxidative response of Cinnamomum camphora seedlings exposed to nitrogen dioxide (NO2) fumigation. Methods: Measurements were made up of the growth, chlorophyll content, chlorophyll fluorescence, antioxidant system and lipid peroxidation of one-year-old C. camphora seedlings exposed to NO2 (0.1, 0.5, and 4 μl/L) fumigation in open top chambers over a period of 60 d. Results: After the first 30 d, 0.5 and 4.0 μl/L NO2 showed insignificant effects on the growth of C. camphora seedlings. However, exposure to 0.5 and 4.0 μl/L NO2 for 15 d significantly reduced their chlorophyll content (P<0.05), enhanced their malondialdehyde (MDA) content and superoxide dismutase (SOD) activity (P<0.05), and also significantly reduced the maximal quantum yield of PSII in the dark [the ratio of variable fluorescence to maximal fluorescence (F v/F m)] (P<0.05). In the latter 30 d, 0.5 μl/L NO2 showed a positive effect on the vitality of the seedlings, which was reflected by a recovery in the ratio of F v/F m and chlorophyll content, and obviously enhanced growth, SOD activity, ascorbate (AsA) content and glutathione reductase (GR) activity (P<0.05); 4.0 μl/L NO2 then showed a negative effect, indicated by significant reductions in chlorophyll content and the ratio of F v/F m, and inhibited growth (P<0.05). Conclusion: The results suggest adaptation of C. camphora seedlings to 60-d exposure to 0.1 and 0.5 μl/L NO2, but not to 60-d exposure to 4.0 μl/L NO2. C. camphora seedlings may protect themselves from injury by strengthening their antioxidant system in response to NO2-induced oxidative stress. PMID:20205305

  3. Impact of elevated O3 on visible foliar symptom, growth and biomass of Cinnamomum camphora seedlings under different nitrogen loads.

    PubMed

    Niu, Junfeng; Zhang, Weiwei; Feng, Zhaozhong; Wang, Xiaoke; Tian, Yuan

    2011-10-01

    The effects of elevated ozone (O(3)) and enhanced nitrogen (N) on the growth and biomass of Cinnamomum camphora, a subtropical evergreen broad-leaved tree species, were investigated. The seedlings, supplied with N (NH(4)NO(3) solution) at 0, 30 and 60 kg ha(-1) year(-1) (simplified as N0, N30, N60, respectively), were exposed to ambient (AA) or elevated O(3) (AA + 60 nmol mol(-1) and AA + 120 nmol mol(-1), designated as AA + 60 and AA + 120, respectively) for the 2009 and 2010 growing seasons. Symptomatic leaf percentages were significantly increased with O(3) concentration. AA + 120 significantly decreased the mean leaf size and chlorophyll content of both 2009- and 2010-emerged leaves, inhibited the growth of stem height and basal diameter, and reduced biomass accumulation of all plant parts except for leaves. By comparison, only the chlorophyll content of 2009-emerged leaves and root dry weight were significantly reduced under AA + 60. Specific leaf area, total leaf area and foliar biomass were not affected even at a higher O(3) level. On the other hand, N loads, especially N60, exerted significantly positive effects on all variables except mean leaf size and shoot/root ratio. No significant interactions between O(3) and N were detected, suggesting that the N supply at ?60 kg ha(-1) year(-1) did not significantly modify the response of C. camphora to O(3) in terms of seedling growth and biomass accumulation. PMID:21853164

  4. An Efficient Protocol for Plantlet Regeneration via Direct Organogenesis by Using Nodal Segments from Embryo-Cultured Seedlings of Cinnamomum camphora L.

    PubMed Central

    Du, Li; Li, Yongpeng; Yao, Yao; Zhang, Liwei

    2015-01-01

    A simple and efficient plantlet regeneration protocol via direct organogenesis was established for camphor tree (Cinnamomum camphora L.). Stem segments with one node (SN explants) from embryo-cultured seedlings (EC seedlings) were used as explants. Murashige and Skoog (MS) medium supplemented with 0.5 mg/L 2, 4-dichlorophenoxyacetic acid and 2.0 mg/L 6-benzyladenine was used to induce cotyledonary embryo germination. This medium was also used for EC seedlings propagation and adventitious bud induction from SN explants. Regenerated plantlets were cultured on hormone-free MS medium for elongation and root induction. The regeneration capability of SN explants was compared by using EC seedling lines established in this research. EC seedling line EL6 exhibited the highest adventitious bud induction frequency (91.7%) and the highest number of buds per responding explant (5.2), which was considered as the most efficient EC seedling line for further gene transformation research. PMID:25962170

  5. Ultrastructural studies on the natural leaf senescence of Cinnamomum camphora.

    PubMed

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

    2013-01-01

    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

  6. Extraction of heavy metals from contaminated soil by Cinnamomum camphora.

    PubMed

    Ho, Jian-Ren; Ma, Hwong-Wen; Wang, Yi-Chung; Ko, Chun-Han; Chang, Fang-Chih; Feng, Fong-Long; Wang, Ya-Nang

    2014-12-01

    83 acres of rice paddy fields in Taoyuan county, Taiwan, were polluted by cadmium (Cd), chromium (Cr) and copper (Cu) through a nearby irrigation channel, and rice plantation was ceased in 1987. Camphor trees (Cinnamomum camphora) have been planted in 2 acre of the above fields since 1991. Heavy metal accumulation of roots, leaves, branches and heartwood of camphor trees were analyzed during 20-year afforestation. Averaged Cd contents of the roots were found larger than the ones of the branches, leaves, sapwood and heartwood of camphor trees growing in three polluted plots. Averaged diameters at breast height (DBH) of the planted camphor trees were 13-15 cm. Cd pollution did not significantly impact the growth of camphor trees, as similar DBH's were found from both polluted and control sites. Annual growths of DBH were from 0.63 to 0.77 cm year(-1). Planting camphor trees sequestered 68.8 ton biomass per acre. During 20-year period, 0.69-1.98 ton C year(-1) ha(-1) were sequestered on three polluted plots. The above numbers exceeded IPCC LULUCF reference values 0.31-0.53 ton C year(-1) ha(-1) for activities at forest lands. PMID:25204813

  7. Feeding stimulant in Cinnamomum camphora for the common bluebottle, Graphium sarpedon nipponum (Lepidoptera: Papilionidae).

    PubMed

    Li, Jing; Wakui, Ryu; Horie, Masanori; Nishimura, Yoshichika; Nishiyama, Yoshihide; Ikeno, Yasunori; Tebayashi, Shin-ichi; Kim, Chul-Sa

    2010-01-01

    The acceptance of camphor tree (Cinnamomum camphora) as a host plant for the larvae of common bluebottle (Graphium sarpedon nipponum) was explained by the presence of feeding stimulants in the leaves. When the active methanol extract of C. camphora leaves was separated into hexane and water layers, both layers showed high feeding activities for the larvae of G. sarpedon nipponum. Bioassay-guided fractionation of the hexane layer resulted in the isolation of a highly active compound, which was identified as a-linolenic acid by nuclear magnetic resonance spectrometry and gas chromatography-mass spectrometry. PMID:21138058

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

    PubMed

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

    2014-01-01

    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

  9. Feeding stimulants for larvae of Graphium sarpedon nipponum (Lepidoptera: Papilionidae) from Cinnamomum camphora.

    PubMed

    Zhang, Yong; Zhan, Zhi-Hui; Tebayashi, Shin-Ichi; Kim, Chul-Sa; Li, Jing

    2015-01-01

    The feeding response of larvae of the swallowtail butterfly, Graphium sarpedon nipponum (Lepidoptera: Papilionidae), is elicited by a methanolic extract from camphor tree (Cinnamomum camphora) leaves. Based on bioassay-guided fractionation, three compounds, isolated from the methanolic extract of fresh leaves of the camphor tree, were revealed to be involved in a multi-component system of feeding stimulants. Structures of these feeding stimulants were identified as sucrose, 5-O-caffeoylquinic acid and quercetin 3-O-?-glucopyranoside by NMR and LC-MS. PMID:26181048

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

    PubMed Central

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

    2014-01-01

    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

  11. Non-stomatal limitation to photosynthesis in Cinnamomum camphora seedings exposed to elevated O3.

    PubMed

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

    2014-01-01

    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 (ΦPSII). 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

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

    NASA Astrophysics Data System (ADS)

    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

    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.

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

    PubMed

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

    2013-12-01

    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

  14. Quantitative analysis of carbon balance in the reproductive organs and leaves of Cinnamomum camphora (L.) Presl.

    PubMed

    Imai, Shunsuke; Ogawa, Kazuharu

    2009-07-01

    We investigated seasonal changes in dry mass and CO(2) exchange rate in fruit and leaves of the evergreen tree Cinnamomum camphora with the aim of quantitatively determining the translocation balance between the two organs. The fruit dry mass growth peaked in both August and October: the first increase was due to fruit pulp development and the second to seed development. Fruit respiration also increased with the rapid increase in fruit dry mass. Therefore, the carbohydrates required for fruit development showed two peaks during the reproductive period. Fruit photosynthesis was relatively high in early August, when fruit potentially re-fixed 75% of respired CO(2), indicating that fruit photosynthesis contributed 15-35% of the carbon requirement for fruit respiration. Current-year leaves completed their growth in June when fruit growth began. Current-year leaves translocated carbohydrates at a rate of approximately 10-25 mg dry weight (dw) leaf(-1) day(-1) into other organs throughout the entire fruit growth period. This rate of translocation from current-year leaves was much higher than the amount of carbohydrate required for reproduction (ca. 3 mg dw fruit(-1) day(-1)). Given the carbon balance between fruit and current-year leaves, carbohydrates for reproduction were produced within the current-year fruit-bearing shoots. C. camphora would be adaptive for steadily supplying enough amount of carbohydrate to the fruits, as there was little competition for carbohydrates between the two organs. As assimilates by leaves are used for processes such as reproduction and the formation of new shoots, photosynthesis by reproductive organs is considered to be important to compensate for reproductive cost. PMID:19396511

  15. Volatile attractants for the common bluebottle, Graphium sarpedon nipponum, from the host, Cinnamomum camphora.

    PubMed

    Li, Jing; Wakui, Ryu; Tebayashi, Shin-ichi; Kim, Chul-Sa

    2010-01-01

    Floral scent has been shown to elicit behavioral responses by butterflies which forage for flowers after receiving appropriate signals. In comparison with investigations about the role of floral scent, those of foliar odor are, however, very few. In this study, the foliar volatiles of Cinnamomum camphora (Lauraceae), which had been collected by air entrainment, exhibited activities toward Graphium sarpedon nipponum (Papilionidae) in both electrophysiological and behavioral tests. The volatiles were analyzed by capillary gas chromatography with electro-antennographic detection (GC-EAD). Two electrophysiological active compounds were found which were determined as nonanal and decanal by using gas chromatography-mass spectrometry (GC-MS). Female butterflies generally tend to show a greater EAG response than males to the headspace volatiles and EAG-active aldehydes. Two EAG-active aldehydes were found in attractant tests to be attractive to both sexes of the butterfly when treated individually. Although the difference between the sexes was not significant, the female butterflies' preference tended to be more active than that of the males. PMID:20944433

  16. [Effects of nitrogen addition on red soil microbes in the Cinnamomum camphora plantation].

    PubMed

    Yu, Pei-Yi; Zhu, Fan; Su, Shao-Feng; Wang, Zhi-Yong; Yan, Wen-De

    2013-08-01

    In order to investigate the effects of nitrogen addition on the red soil microbial communities in Cinnamomum camphora plantation, three treatments of nitrogen addition were designated as control (N0: 0 g x m(-2)), low nitrogen (N1: 5 g x m(-2)) and high nitrogen (N2 :15 g x m(-2)). Soil microbial numbers, microbial biomass carbon (C), biomass N and microbial community functional diversity were analyzed using the methods of plate counting, chloroform fumigation and BIOLOG system, respectively. The results showed that the numbers of bacteria in N1 and N2 were significantly higher than the control 1 month after nitrogen addition, but significantly lower than the control 13 months after nitrogen addition, and the number of fungi and actinomycetes were not significantly changed after nitrogen addition. The soil microbial biomass C, N increased with the increase of nitrogen at 1 month, but the soil microbial biomass C increased significantly 13 months after nitrogen addition when compared with 1 month after nitrogen addition. The soil microbial biomass N was lower 13 months after nitrogen addition when compared with 1 month after nitrogen addition, but the difference was not significant (P > 0.05). The variation of the carbon utilization efficiency of soil microbial communities was resulted from the nitrogen addition. The indices of Shannon index, Simpson index and McIntosh index were calculated to show the differences in nitrogen treatments and in times, which turned out to be insignificant. PMID:24191573

  17. Removal of copper(II) ions by a biosorbent--Cinnamomum camphora leaves powder.

    PubMed

    Chen, Hao; Dai, Guoliang; Zhao, Jie; Zhong, Aiguo; Wu, Junyong; Yan, Hua

    2010-05-15

    In the present study, Cinnamomum camphora leaves powder (CLP) was investigated as a biosorbent for the removal of copper ions from aqueous solutions. The biosorbents before and after adsorption were measured by EDS and FT-IR. Kinetic data and sorption equilibrium isotherms were carried out in batch process. The adsorption kinetic experiments revealed that there are three stages in the whole adsorption process. It was found that Cu(II) adsorption onto CLP for different initial Cu(II) concentrations all followed pseudo-second order kinetics and were mainly controlled by the film diffusion mechanism. Batch equilibrium results at different temperatures suggest that Cu(II) adsorption onto CLP can be described perfectly with Langmuir isotherm model compared to Freundlich and D-R isotherm models, and the characteristic parameters for each adsorption isotherm were also determined. Thermodynamic parameters calculated show that the adsorption process has been found to be endothermic in nature. The analysis for the values of the mean free energies of adsorption (E(a)), the Gibbs free energy (DeltaG(0)) and the effect of ionic strength all demonstrate that the whole adsorption process is mainly dominated by ion-exchange mechanism, accompanied by a certain amount of surface complexation which has been verified by variations in EDS and FT-IR spectra and pH value before and after adsorption. Regeneration studies show CLP possesses an excellent reusability. PMID:20022692

  18. [Responses of tree-ring width of Cinnamomum camphora to climate change in Dagangshan forest area of Jiangxi Province].

    PubMed

    Wang, Bing; Gao, Peng; Guo, Hao; Leng, Ling

    2009-01-01

    By using ARSTAN software to wipe off the growth trend of tree-ring width and transform the series into index form, the tree chronology of Cinnamomum camphora in Dagangshan forest area of Jiangxi Province was built, and the responses of the tree-ring width of C. camphora to climate change in study area were studied. The results showed that the built tree chronology included abundant environmental climatic information, which could be used in dendrochronological research. In study area, the tree-ring width of C. camphora was positively correlated to the mean monthly temperature in growth season, especially to that of April and May (P < 0.05). The correlation of the tree-ring width with monthly precipitation was more complicated, being significant negative with the precipitation in current May (P < 0.01) and last December (P < 0.05), while significant positive with that in current June and August (P < 0.05). The tree-ring width had a good correlation with the humidity index of current May, June, August, and September. Temperature and precipitation had obvious integrative effects on the tree-ring width of C. camphora in Dagangshan forest area of Jiangxi Province. PMID:19449568

  19. [Effects of understory removal on soil labile organic carbon pool in a Cinnamomum camphora plantation].

    PubMed

    Wu, Ya-Cong; Li, Zheng-Cai; Cheng, Cai-Fang; Liu, Rong-Jie; Wang, Bin; Geri, Le-Tu

    2013-12-01

    Taking a 48-year-old Cinnamomum camphora plantation in the eastern area of our subtropics as test object, this paper studied the labile organic carbon contents and their ratios to the total organic carbon (TOC) in 0-60 cm soil layer under effects of understory removal (UR). As compared with no understory removal (CK), the soil TOC and easily-oxidized carbon (EOC) contents under UR decreased, with a decrement of 4.8% - 34.1% and 27.1% - 36.2%, respectively, and the TOC and EOC contents had a significant difference in 0-10 cm and 0-20 cm layers, respectively. The water-soluble organic carbon (WSOC) (except in 0-10 cm and 10-20 cm layers) and light fraction organic matter (LFOM) under UR increaesd, but the difference was not significant. The ratio of soil WSOC to soil TOC in UR stand was higher than that in CK stand, while the ratio of soil EOC to soil TOC showed an opposite trend. In the two stands, soil WSOC, EOC, and LFOM had significant or extremely significant correlations with soil TOC, and the correlation coefficients of soil EOC and LFOM with soil TOC were higher in UR stand than in CK, but the correlation coefficient between soil WSOC and TOC was in opposite. The soil EOC, LFOM, and TOC in the two stands were significantly or extremely significantly correlated with soil nutrients, but the soil WSOC in UR stand had no significant correlations with soil hydrolyzable N, available P, exchangeable Ca, and exchangeable Mg. PMID:24697049

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

    PubMed

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

    2008-10-01

    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

  1. Characterization of medium-chain triacylglycerol (MCT)-enriched seed oil from Cinnamomum camphora (Lauraceae) and its oxidative stability.

    PubMed

    Hu, Jiang-Ning; Zhang, Bing; Zhu, Xue-Mei; Li, Jing; Fan, Ya-Wei; Liu, Rong; Tang, Liang; Lee, Ki-Teak; Deng, Ze-Yuan

    2011-05-11

    Medium-chain triacylglycerol (MCT)-enriched oil was extracted by supercritical fluid extraction of carbon dioxide (SFE-CO(2)) from Cinnamomum camphora seeds. The SFE-CO(2) process was optimized using the Box-Behnken design (BBD). The maximum oil yield (42.82%) was obtained under the optimal SFE-CO(2) conditions: extraction pressure, 21.16 MPa; extraction temperature, 45.67 C; and extraction time, 2.38 h. Subsequently, the physicochemical characteristics, fatty acid composition, triacylglycerol (TAG) composition, tocopherol content, and DSC profile as well as oxidative stabilities of C. camphora seed oil (CCSO) were studied. Results showed that CCSO contained two major medium-chain fatty acids, capric acid (53.27%) and lauric acid (39.93%). The predominant TAG species in CCSO was LaCC/CLaC (ECN 32, 79.29%). Meanwhile, it can be found that CCSO had much higher oxidative stabilities than coconut oil due to the higher content of tocopherols in CCSO (?-tocopherol, 8.67 0.51 mg/100 g; ?-tocopherol, 22.6 1.02 mg/100 g; ?-tocopherol, 8.38 0.47 mg/100 g). Conclusively, CCSO with such a high level of MCTs and high oxidative stabilities could be potentially applied in special food for specific persons such as weak patients and overweight persons because oils enriched in MCTs can be rapidly absorbed into body to provide energy without fat accumulation. PMID:21456611

  2. Promotion of hyphal growth and underlying chemical changes in Antrodia camphorata by host factors from Cinnamomum camphora.

    PubMed

    Hsu, Feng-Lin; Chou, Cheng-Jen; Chang, Yi-Chieh; Chang, Tun-Tschu; Lu, Mei-Kuang

    2006-01-15

    The aim of this research was to investigate the hyphal growth-promoting factors (HGFs) of Antrodia camphorata from the host-related species, Cinnamomum camphora (CC) and the underlying chemical produced. The HGF was identified in the polysaccharide fraction of CC at levels ranging from 80 to 320 mg L(-1), and it maximally stimulated growth to 5.50 g L(-1) during a 14-day culture period compared to that of the control of 2.88 g L(-1). We also investigated the nature and chemical composition of the CC polysaccharide. Herein, size-exclusion column chromatography followed by high-performance anion-exchange chromatography after complete hydrolysis of the CC polysaccharide was performed to derive its molecular weight and sugar composition. The Mw values of the CC polysaccharide were determined to be 728.2, 187.5, 28.7, 7.5, and 1.9 kDa. Compositional analysis of the CC polysaccharide showed that galactosamine, mannose, and glucose were the major monosaccharides. Time-course studies of mycelial extracts of cultures revealed that prolonged incubation with the water-soluble extracts of CC resulted in an increase in the relative amounts of two lanostane-type compounds, i.e., dehydrosulphurenic acid and 15alpha-acetyl-dehydrosulphurenic acid, which are found in the fruiting bodies of A. camphorata. This finding offers the possibility of the reliable production of this medicinal fungus under laboratory conditions compared to its limited slow growth in nature. PMID:16219379

  3. Repellent and insecticidal activities of essential oils from Artemisia princeps and Cinnamomum camphora and their effect on seed germination of wheat and broad bean.

    PubMed

    Liu, C H; Mishra, A K; Tan, R X; Tang, C; Yang, H; Shen, Y F

    2006-10-01

    Repellent and insecticidal activities of essential oils extracted from leaves of Artemisia princeps Pamp and seeds of Cinnamomum camphora (L.) Presl. against storage pests Sitophillus oryzae L. and Bruchus rugimanus Bohem were investigated. Results showed that the two individual oils displayed good, but their mixture (1:1) exhibited much better repellent activities at concentrations from 250 to 1000 microg g(-1) and insecticidal actions at concentrations 1000 microg g(-1) against the test beetles S. oryzae and B. rugimanus. Oils from A. princeps and C. camphora applied individually were significantly toxic to seed germination of wheat at 500 microg ml(-1). However, no toxic effects were found when the two oils were mixed (1:1 w/w) at the same concentration. These observations indicated that the mixture of the two plant-derived oils had a synergic effect and could be used in the control of storage pests. PMID:16230008

  4. Propylene epoxidation over biogenic Au/TS-1 catalysts by Cinnamomum camphora extract in the presence of H2 and O2

    NASA Astrophysics Data System (ADS)

    Du, Mingming; Huang, Jiale; Sun, Daohua; Li, Qingbiao

    2016-03-01

    The Au/TS-1 catalysts with different Au nanoparticles (NPs) sizes ranging from 3.1 to 8.4 nm but the same Au loading of 0.5 wt% were prepared by Cinnamomum camphora (CC) extract, and were used for propylene epoxidation. The results showed that the interaction between Au and TS-1 support surface is important for propylene epoxidation and much smaller Au NPs (<3 nm) are the dominant active sites. After reaction of 100 h, there is no decreasing in both the activity and the PO selectivity for the Au/TS-1 catalysts, and only 1.8 wt% of the carbonaceous deposits on the surface of the catalyst after reaction, suggesting that the desorption of the product from the modified catalysts surface by residual biomolecules is much easier.

  5. [Inhibition of decomposing leaf litter of Cinnamomum camphora on growth of Capsicum annu- um and the alleviation effect of nitrogen application].

    PubMed

    Chen, Hong; Hu, Ting-xing; Wang, Qian; Hu, Hong-ling; Jiang, Xue; Zhou, Guang-liang; Chen, Gang

    2015-02-01

    Effects of decomposing leaf litter of Cinnamomum camphora on growth, physiological and phenological traits of Capsicum annuum, and modification of these effects by nitrogen application were investigated using a pot experiment. C. camphora leaf litter was applied at rate of 0, 25, 50 100 g per pot, resulting into four treatments, i.e., CK (the control), L25, L50, and L100. Nitrogen application was firstly performed on the 39th d of decomposition (3.0 g urea was added to each pot six times). Leaf area, plant height, basal diameter and biomass production of C. annuum were all inhibited sharply by exposure to the leaf litter, and the inhibition effect increased with the increasing leaf litter in terms of both the intensity and the stability. Treated with L25, budding number reduced by 88.7% averagely during 55th-75th d, and the rate of fructification plant decreased by 40% on the 96th d of decomposition, while neither buds nor fruits were observed when exposed to L50 and L100 at that time. Pigment contents and net photosynthetic rate (Pn) were impacted due to leaf litter addition, and malonaldehyde (MDA) was only markedly promoted by L100. Inhibition on growth and development of C. annuum caused by leaf litter decomposition could be alleviated by nitrogen application. Leaf area treated with leaf litter recovered to the control level on the 52nd d after nitrogen application, and similar results appeared on the 83rd d after nitrogen application for other growth traits. Budding and fructification status were also visibly improved. PMID:26094461

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

    PubMed

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

    2012-04-01

    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

  7. Lipozyme RM IM-catalyzed acidolysis of Cinnamomum camphora seed oil with oleic acid to produce human milk fat substitutes enriched in medium-chain fatty acids.

    PubMed

    Zou, Xian-Guo; Hu, Jiang-Ning; Zhao, Man-Li; Zhu, Xue-Mei; Li, Hong-Yan; Liu, Xiao-Ru; Liu, Rong; Deng, Ze-Yuan

    2014-10-29

    In the present study, a human milk fat substitute (HMFS) enriched in medium-chain fatty acids (MCFAs) was synthesized through acidolysis reaction from Cinnamomum camphora seed oil (CCSO) with oleic acid in a solvent-free system. A commercial immobilized lipase, Lipozyme RM IM, from Rhizomucor miehei, was facilitated as a biocatalyst. Effects of different reaction conditions, including substrate molar ratio, enzyme concentration, reaction temperature, and reaction time were investigated using response surface methodology (RSM) to obtain the optimal oleic acid incorporation. After optimization, results showed that the maximal incorporation of oleic acid into HMFS was 59.68%. Compared with CCSO, medium-chain fatty acids at the sn-2 position of HMFS accounted for >70%, whereas oleic acid was occupied predominantly at the sn-1,3 position (78.69%). Meanwhile, triacylglycerol (TAG) components of OCO (23.93%), CCO (14.94%), LaCO (13.58%), OLaO (12.66%), and OOO (11.13%) were determined as the major TAG species in HMFS. The final optimal reaction conditions were carried out as follows: substrate molar ratio (oleic acid/CCSO), 5:1; enzyme concentration, 12.5% (w/w total reactants); reaction temperature, 60 °C; and reaction time, 28 h. The reusability of Lipozyme RM IM in the acidolysis reaction was also evaluated, and it was found that it could be reused up to 9 times without significant loss of activities. Urea inclusion method was used to separate and purify the synthetic product. As the ratio of HMFS/urea increased to 1:2, the acid value lowered to the minimum. In a scale-up experiment, the contents of TAG and total tocopherols in HMFS (modified CCSO) were 77.28% and 12.27 mg/100 g, respectively. All of the physicochemical indices of purified product were within food standards. Therefore, such a MCFA-enriched HMFS produced by using the acidolysis method might have potential application in the infant formula industry. PMID:25298236

  8. 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

    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

    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

  9. [Spectroscopic analysis of the decay resistance of wood treated with extracts from the xylem of Cinnamomum Camphora with XRD and FTIR approaches].

    PubMed

    Li, Quan; Wang, Xiao-Xian; Lin, Jin-Guo

    2014-03-01

    Four kinds of extracts from the xylem of C. Camphora, ACQ and camphor were selected to make wood preservatives for laboratory toxicity test of wood preservatives for decay fungus. The results showed that the treated blocks with 4% ACQ and 10% methanol extracts could meet the demand of degree I of preservation and showed strong resistance to brown-rot fungus at tack. The wood treated with 4% camphor extracts, 10% ethyl acetate extracts, and 10% acetone extracts reached the demand of degree II and showed moderate decay resistance. The blocks treated with 10% hot water extracts and untreated samples meet the demand of degree III. Through XRD comparison, the author was found that the preservative effects of four extracts are proportional to the degree of crystallinity. Crystallization fields 2 theta diffraction angle were ordered from larger to little as 10% hot wa-ter extracts > untreated samples > 10% acetone extracts > 10% methanol extracts > 1% ethyl acetate extracts. According to FTIR analysis, the amount of degraded cellulose and hemicellulose increased with the decline of characteristic absorption peak at 1,374, 1,160, 1,106, 1,056 and 897 cm(-1), meaning that the preservative effect of corresponding preservatives were getting worse. The peak height of characterization of lignin is higher compared to the untreated wood. I1,510/I1,738, I1,510/I1,374, l51,510/ I1,160 of the treated blocks with 10% methanol extracts and 4% ACQ are the smallest in all the treated blocks, which proved that the degradation ability of brown--rot fungus to the holocellulose is the weakest, and the wood preservative is best. PMID:25208421

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

    PubMed

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

    2011-12-01

    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

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

    PubMed

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

    2014-07-01

    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

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

    PubMed

    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

    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

  13. Camphor--a fumigant during the Black Death and a coveted fragrant wood in ancient Egypt and Babylon--a review.

    PubMed

    Chen, Weiyang; Vermaak, Ilze; Viljoen, Alvaro

    2013-01-01

    The fragrant camphor tree (Cinnamomum camphora) and its products, such as camphor oil, have been coveted since ancient times. Having a rich history of traditional use, it was particularly used as a fumigant during the era of the Black Death and considered as a valuable ingredient in both perfume and embalming fluid. Camphor has been widely used as a fragrance in cosmetics, as a food flavourant, as a common ingredient in household cleaners, as well as in topically applied analgesics and rubefacients for the treatment of minor muscle aches and pains. Camphor, traditionally obtained through the distillation of the wood of the camphor tree, is a major essential oil component of many aromatic plant species, as it is biosynthetically synthesised; it can also be chemically synthesised using mainly turpentine as a starting material. Camphor exhibits a number of biological properties such as insecticidal, antimicrobial, antiviral, anticoccidial, anti-nociceptive, anticancer and antitussive activities, in addition to its use as a skin penetration enhancer. However, camphor is a very toxic substance and numerous cases of camphor poisoning have been documented. This review briefly summarises the uses and synthesis of camphor and discusses the biological properties and toxicity of this valuable molecule. PMID:23666009

  14. Biological activities of aqueous extract from Cinnamomum porrectum

    NASA Astrophysics Data System (ADS)

    Farah, H. Siti; Nazlina, I.; Yaacob, W. A.

    2013-11-01

    A study was carried out to evaluate biological activities of an extract obtained from Cinnamomum porrectum under reflux using water. Aqueous extract of Cinnamomum porrectum was tested for antibacterial activity against six Gram-positive and eight Gram-negative bacteria as well as MRSA. The results confirmed that the aqueous extract of Cinnamomum porrectum was bactericidal. Cytotoxic tests on Vero cell culture revealed that Cinnamomum porrectum was non-toxic which IC50 value higher than 0.02 mg/mL. Antiviral activity was tested based on the above IC50 values together with the measured EC50 values to obtain Therapeutic Index. The result showed that Cinnamomum porrectum has the ability to inhibit viral replication of HSV-1 in Vero cells.

  15. Effect of Cinnamomum zeylanicumon on Spermatogenesis

    PubMed Central

    Khaki, Arash

    2015-01-01

    Background: In modern countries today, herbal medicines are known to help in the treatment of various diseases, as rich sources of antioxidants and minerals. Objectives: To study the effect of Cinnamomum zeylanicum (C. zeylanicum) on spermatogenesis in rats. Materials and Methods: In this experimental study, Wistar male rats (n = 20) were divided into two groups, a control group (n = 10) and a Cinnamomum zeylanicum group (n = 10). The subjects in the cinnamon group received 75 mg/kg/day cinnamon by gavage for 28 days, while the controls received an equal volume of distilled water daily. Animals were kept in standardized conditions. On day 28, a 5 mL blood sample from each rat was taken from tail area to measure testosterone, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and malondialdehyde (MDA) levels. Testes were collected and were then prepared for sperm analysis by the WHO method. Results: Sperm quality parameters, total serum testosterone, SOD, CAT, and GPX levels were significantly increased in the cinnamon group in comparison to controls (P < 0.05). Also, rats in the cinnamon group showed a significant decrease in the level of plasma MDA (P < 0.05) in comparison to controls. There were no significant differences between the groups in testis weight (P > 0.05). Conclusions: The administration of 75 mg/kg/day cinnamon significantly increased the sperm population, motility and viability, which supports the theory that in mammalians, cinnamon has a beneficial effect on spermatogenesis. PMID:25838932

  16. Bioanalytical evaluation of Cinnamomum zeylanicum essential oil.

    PubMed

    Saleem, Muhammad; Bhatti, Haq Nawaz; Jilani, Muhammad Idrees; Hanif, Muhammad Asif

    2015-01-01

    This manuscript describes the antioxidant activity of essential oil of Cinnamon (Cinnamomum zeylanicum) bark extracted by supercritical fluid extraction (SCFE), hydro distillation and steam distillation. The cinnamon bark essential oil exhibited a wide range of total phenolic contents, total flavonoid contents, reducing power, inhibition of linoleic acid peroxidation and DPPH radical-scavenging activity (IC50). Bioactivity of cinnamon essential oil was assayed against various bacterial strains including Bacillus subtilis, Escherichia coli, Pastrurella multocida and Straphylococcus aureus and fungal strains including Aspergillus niger and Aspergillus flavus. More essential oil yield was obtained using SCFE in comparison to other methods. The oil extracted by SCFE was dominated by cinnamaldehyde, limonene, copaene, naphthalene, heptane, bicyclo[4.2.0]octa-1,3,5-triene and 2-propenal. Due to the presence of cinnamaldehyde in the essential oil of cinnamon bark it acts as a good antioxidant and antimicrobial agent. PMID:25605550

  17. Nitrogen isotope variations in camphor (Cinnamomum Camphora) leaves of different ages in upper and lower canopies as an indicator of atmospheric nitrogen sources.

    PubMed

    Xiao, Hua-Yun; Wu, Liang-Hong; Zhu, Ren-Guo; Wang, Yan-Li; Liu, Cong-Qiang

    2011-02-01

    Nitrogen isotopic composition of new, middle-aged and old camphor leaves in upper and lower canopies has been determined in a living area, near a motorway and near an industrial area (Jiangan Chemical Fertilizer Plant). We found that at sites near roads, more positive ?(15)N values were observed in the camphor leaves, especially in old leaves of upper canopies, and ??(15)N=?(15)N(upper)-?(15)N(lower)>0, while those near the industrial area had more negative ?(15)N values and ??(15)N<0. These could be explained by two isotopically different atmospheric N sources: greater uptake from isotopically heavy pools of atmospheric NO(x) by old leaves in upper canopies at sites adjacent to roads, and greater uptake of (15)N-depleted NH(y) in atmospheric deposition by leaves at sites near the industrial area. This study presents novel evidence that (15)N natural abundance of camphor leaves can be used as a robust indicator of atmospheric N sources. PMID:21130551

  18. Pharmaceutical applications and phytochemical profile of Cinnamomum burmannii

    PubMed Central

    Al-Dhubiab, Bandar E.

    2012-01-01

    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

  19. Study on Cinnamomum oils: compositional pattern of seven species grown in Vietnam.

    PubMed

    Son, Le C; Dai, Do N; Thang, Tran D; Huyen, Duong D; Ogunwande, Isiaka A

    2014-01-01

    The leaf essential oils of seven Vietnamese species of the genus Cinnamomum were analyzed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC/MS). The results showed that the species fall into three groups in which one group contains aromatic components, while the second group contains both terpenes and aromatic constituents and the third group contains only terpene constituents. The first group had only Cinnamomum curvifolium as its member and produced oil rich in benzyl cinnamate and benzyl benzoate. The second group producing mixture of phenylpropanoids and oxygenated monoterpene components includes leaves of Cinnamomum kunstleri (methyl eugenol, terpinen-4-ol and 1,8-cineole) and Cinnamomum mairei (eugenol, 1, 8-cineole, neryl acetate and eugenol acetate). The third group rich in terpene constituents could also be divided into two classes. The first class produced oils rich in monoterpene components and includes Cinnamomum damhaensis (linalool, ?-pinene, ?-pinene and 1,8-cineole), Cinnamomum cambodianum (linalool and terpinen-4-ol) and Cinnamomum caryophyllus (1,8-cineole, ?-pinene and camphene). The second class contains oil with abundance of sesquiterpene compounds and peculiar to Cinnamomum rigidifolium (?-selinene, ?-caryophyllene and ?-copaene). This paper discusses further the chemotaxonomic importance of these results and previous data on essential oils of Cinnamomum species analysed from Vietnam. PMID:25274473

  20. Determination of volatiles produced during radiation processing in Laurus cinnamomum

    NASA Astrophysics Data System (ADS)

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

    2009-07-01

    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.

  1. Antileukemic activity of lignans and phenylpropanoids of Cinnamomum parthenoxylon.

    PubMed

    Adfa, Morina; Rahmad, Rizki; Ninomiya, Masayuki; Yudha S, Salprima; Tanaka, Kaori; Koketsu, Mamoru

    2016-02-01

    In this study, we evaluated the in vitro cytotoxicity of fractions and isolated constituents from Cinnamomum parthenoxylon woods against human leukemia HL-60 and U937 cells. The n-Hex, EtOAc, and MeOH-H2O fractions of the woods inhibited cell proliferation in both cell lines. Our phytochemical investigation of the n-Hex and EtOAc fractions led to the isolation of lignans and phenylpropanoids, whose chemical structures were confirmed by spectroscopic analyses. All isolated compounds were evaluated for their in vitro antileukemic activity; especially, hinokinin and cubebin exhibited strong inhibition toward U937 cell proliferation. Morphological observation indicated that these cytotoxic actions were mediated by apoptosis. Our findings suggested that an oxygenated functional group at the C-9 position in dibenzylfuran skeleton contributed their potency. In addition, these results enhanced the ethnopharmacological value of C. parthenoxylon. PMID:26774581

  2. Origins and evolution of cinnamon and camphor: A phylogenetic and historical biogeographical analysis of the Cinnamomum group (Lauraceae).

    PubMed

    Huang, Jian-Feng; Li, Lang; van der Werff, Henk; Li, Hsi-Wen; Rohwer, Jens G; Crayn, Darren M; Meng, Hong-Hu; van der Merwe, Marlien; Conran, John G; Li, Jie

    2016-03-01

    Tropical and subtropical amphi-Pacific disjunction is among the most fascinating distribution patterns, but received little attention. Here we use the fossil-rich Cinnamomum group, a primarily tropical and subtropical Asian lineage with some species distributed in Neotropics, Australasia and Africa to shed light upon this disjunction pattern. Phylogenetic and biogeographic analyses were carried out using sequences of three nuclear loci from 94 Cinnamomum group and 13 outgroup samples. Results show that although there are three clades within a monophyletic Cinnamomum group, Cinnamomum and previously recognized subdivisions within this genus were all rejected as natural groups. The Cinnamomum group appears to have originated in the widespread boreotropical paleoflora of Laurasia during the early Eocene (ca. 55Ma). The formation and breakup of the boreotropics seems to have then played a key role in the formation of intercontinental disjunctions within the Cinnamomum group. The first cooling interval (50-48Ma) in the late early Eocene resulted in a floristic discontinuity between Eurasia and North America causing the tropical and subtropical amphi-Pacific disjunction. The second cooling interval in the mid-Eocene (42-38Ma) resulted in the fragmentation of the boreotropics within Eurasia, leading to an African-Asian disjunction. Multiple dispersal events from North into South America occurred from the early Eocene to late Miocene and a single migration event from Asia into Australia appears to have occurred in the early Miocene. PMID:26718058

  3. Development of an effective and efficient DNA isolation method for Cinnamomum species.

    PubMed

    Bhau, B S; Gogoi, G; Baruah, D; Ahmed, R; Hazarika, G; Ghosh, S; Borah, B; Gogoi, B; Sarmah, D K; Nath, S C; Wann, S B

    2015-12-01

    Different species of Cinnamomum are rich in polysaccharide's and secondary metabolites, which hinder the process of DNA extraction. High quality DNA is the pre-requisite for any molecular biology study. In this paper we report a modified method for high quality and quantity of DNA extraction from both lyophilized and non-lyophilized leaf samples. Protocol reported differs from the CTAB procedure by addition of higher concentration of salt and activated charcoal to remove the polysaccharides and polyphenols. Wide utility of the modified protocol was proved by DNA extraction from different woody species and 4 Cinnamomum species. Therefore, this protocol has also been validated in different species of plants containing high levels of polyphenols and polysaccharides. The extracted DNA showed perfect amplification when subjected to RAPD, restriction digestion and amplification with DNA barcoding primers. The DNA extraction protocol is reproducible and can be applied for any plant molecular biology study. PMID:26041191

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

    PubMed

    Sharma, Vasundhara; Rao, Lingamallu Jagan Mohan

    2014-01-01

    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

  5. Seedling disease in Michigan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugar beet seedlings (24 entries of a larger genetic population constructed to dissect Rhizoctonia disease reaction in sugar beet) were screened for their response to a highly virulent isolate of Rhizoctonia solani AG 2-2. Seedlings were grown to the two-leaf stage in the greenhouse, thinned to 15 p...

  6. Phytochemical investigation of Annulohypoxylon ilanense, an endophytic fungus derived from Cinnamomum species.

    PubMed

    Wu, Ming-Der; Cheng, Ming-Jen; Chen, Ih-Sheng; Su, Yung-Shun; Hsieh, Sung-Yuan; Chang, Hsun-Shuo; Chang, Chun-Wei; Yuan, Gwo-Fang

    2013-03-01

    Cultivation of the fungal strain Annulohypoxylon ilanense, an endophytic fungus isolated from the wood of medicinal plant Cinnamomum species, resulted in the isolation of one new furanoid derivative, ilanefuranone (1), one new pyrrole alkaloid, ilanepyrrolal (2), and one new biarylpropanoid derivative, ilanenoid (3), together with 22 known compounds, of which one ?-tetralone analog, (-)-(4R)-3,4-dihydro-4,6-dihydroxynaphthalen-1(2H)-one (4) was isolated for the first time from a natural source. The structures were elucidated on the basis of physicochemical evidence, in-depth NMR spectroscopic analysis, and high-resolution mass spectrometry, and the antimycobacterial activities were also evaluated. PMID:23495165

  7. REFORESTATION AND SEEDLING SYMBIONTS

    EPA Science Inventory

    Tree seedlings are dependent on symbiotic associations with microorganisms including bacteria, fungi, and actinomycetes for normal growth and development. itrogen fixing leguminous and non-leguminous trees form symbiotic relationships with Rhizobium (bacteria) and Frankia (actino...

  8. Direct Analysis in Real Time by Mass Spectrometric Technique for Determining the Variation in Metabolite Profiles of Cinnamomum tamala Nees and Eberm Genotypes

    PubMed Central

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

    2012-01-01

    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

  9. Immunosuppressive Effects of A-Type Procyanidin Oligomers from Cinnamomum tamala

    PubMed Central

    Chen, Liang; Yang, Yang; Yuan, Pulong; Yang, Yifu; Chen, Kaixian; Jia, Qi; Li, Yiming

    2014-01-01

    Cinnamon barks extracts have been reported to regulate immune function; however, the component(s) in cinnamon barks responsible for this effect is/are not yet clear. The aim of this study is to find out the possible component(s) that can be used as therapeutic agents for immune-related diseases from cinnamon bark. In this study, the immunosuppressive effects of fraction (named CT-F) and five procyanidin oligomers compounds, cinnamtannin B1, cinnamtannin D1 (CTD-1), parameritannin A1, procyanidin B2, and procyanidin C1, from Cinnamomum tamala or Cinnamomum cassia bark were examined on splenocytes proliferation model induced by ConA or LPS. Then, the effects of activated compound CTD-1 on cytokine production and 2,4-dinitrofluorobenzene (DNFB) induced delayed-type hypersensitivity (DTH) response were detected to evaluate the immunosuppressive activity of CTD-1. It was found that CT-F and CTD-1 significantly inhibited the splenocyte proliferation induced by ConA or LPS. CTD-1 dose-dependently reduced the level of IFN-? and IL-2 and intensively suppressed DNFB-induced DTH responses. These findings suggest that the immunosuppressive activities of cinnamon bark are in part due to procyanidin oligomers. CTD-1 may be a potential therapeutic agent for immune-related diseases. PMID:25530780

  10. Effects of the polyphenol content on the anti-diabetic activity of Cinnamomum zeylanicum extracts.

    PubMed

    IM, Krishnakumar; Issac, Abin; NM, Johannah; Ninan, Eapen; Maliakel, Balu; Kuttan, Ramadassan

    2014-09-01

    Cinnamomum zeylanicum is a popular kitchen spice widely investigated for insulin potentiating effects. Though a group of water soluble polyphenols belonging to the oligomeric procyanidins has been identified as the bioactive principle, the lack of systematic information on the effect of the polyphenol content on safety and anti-diabetic efficacy remains as a major limitation for the development of optimized and standardized cinnamon extracts for functional use. In the present paper, water soluble extracts of Cinnamomum zeylanicum containing 45 and 75% gallic acid equivalents (GAE) of polyphenol content were prepared by a novel process and characterized by tandem mass spectrometry. The polyphenol enhanced extracts were shown to be safe and offered better antioxidant potential, hypoglycemic effect, hypolipidimic effect, and significant decrease in other biochemical parameters as compared to the standard aqueous extract containing 15% GAE, when administered to streptozotocin-induced diabetic rats at 200 mg per kg b.w. for 30 days. The efficacy of polyphenol extracts in lowering blood glucose levels and ameliorating oxidative stress was further demonstrated in humans by administrating 'procynZ-45' containing 45% GAE polyphenols at a relatively low dosage of (125 mg × 2) per day for 30 days to 15 volunteers who had elevated fasting blood glucose levels; but not involved in any medication. PMID:25051315

  11. Germination and seedling development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cottonseed germination and seedling development are highly sensitive to the environment at planting and for several weeks after that. Major factors that affect germination and development are temperature, water availability, soil conditions such as compaction, rhizosphere gases, and seed and seedlin...

  12. Terminating red imported fire ants using Cinnamomum osmophloeum leaf essential oil.

    PubMed

    Cheng, Sen-Sung; Liu, Ju-Yun; Lin, Chun-Ya; Hsui, Yen-Ray; Lu, Mei-Chun; Wu, Wen-Jer; Chang, Shang-Tzen

    2008-03-01

    Eleven compounds from indigenous cinnamon (Cinnamomum osmophloeum) leaf essential oil were identified by GC-MS and the dominant constituent was trans-cinnamaldehyde (79.85%). The toxicity of leaf essential oil and trans-cinnamaldehyde were then determined to study their effectiveness in controlling the red imported fire ant, Solenopsis invicta Buren. The results of the toxicity tests indicated that both the indigenous cinnamon leaf essential oil and trans-cinnamaldehyde had an excellent inhibitory effect in controlling the red imported fire ant. The LT(50) values for both 2% leaf essential oil and 2% trans-cinnamaldehyde after open exposure were 105.0min and 32.2min; after close exposure were 18.5min and 21.2min, respectively. PMID:17369041

  13. Photostimulated luminescence detection and radiation effects on cinnamon (Cinnamomum zeylanicum) spice.

    PubMed

    Marcazz, J; Sanchez-Barrera, C E; Urbina-Zavala, A; Cruz-Zaragoza, E

    2015-10-01

    The increase of disease borne pathogens in foods has promoted the use of new technologies in order to eliminate these pathogen microorganisms and extend the shelf-life of the foodstuffs. In particular, Cinnamon (Cinnamomum zeylanicum) contains an important number of pathogen microorganisms and it is frequently sterilized by gamma radiation. However, it is important to develop the detection methods for irradiated food in order to keep the dose control and also to analyze the radiation effects in their chemical property. This work reports (i) the photostimulated luminescence (PSL) detection of irradiated cinnamon and thermoluminescence (TL) detection of the inorganic polymineral fraction separated from this spice, and (ii) the proximate chemical analysis carried out on fat, protein and dietetic fiber contents. The detection limits using the PSL and TL methods were 500 Gy and 10 Gy, respectively, and the fat content was increased significantly with the gamma dose that could be related to the lipid oxidation in the cinnamon. PMID:26133665

  14. Characterization of the leaf essential oils of an endemic species Cinnamomum perrottetii from Western Ghats, India.

    PubMed

    Sriramavaratharajan, Venkatraman; Sudha, Veerappan; Murugan, Ramar

    2016-05-01

    Essential oils from the leaf of Cinnamomum perrottetii Meissn. collected from three distinct populations in the southern Western Ghats, India were analysed by GC-FID and GC-MS. A total of 56 volatile constituents representing 92.2-96.3% of the oils were identified. Variations in the chemical constituents of the oils were found. Only three major components namely, ?-pinene (5.1-6.6%), tau-cadinol (8.7-20.5%) and ?-cadinol (7.3-13%) out of 10 were found in all three samples. To the best of our knowledge, this is the first report on the chemical compositions of leaf essential oil of C. perrottetii. PMID:26453373

  15. Medicinal properties of ‘true’ cinnamon (Cinnamomum zeylanicum): a systematic review

    PubMed Central

    2013-01-01

    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. PMID:24148965

  16. Seedling Germination: Seedlings Follow Sunshine and Fresh Air.

    PubMed

    Potuschak, Thomas; Bachmair, Andreas

    2015-06-29

    The journey from seedling to plant requires guidance in the dark to establish which directions the roots and shoots should grow. A new study shows that, after germinating in darkness, plant seedlings sense the oxygen content of the surrounding airspace to guide further development. PMID:26126283

  17. Evaluation of Cinnamomum osmophloeum Kanehira Extracts on Tyrosinase Suppressor, Wound Repair Promoter, and Antioxidant

    PubMed Central

    Lee, Man-Gang; Kuo, Su-Yu; Yen, Shih-Yu; Hsu, Hsia-Fen; Leung, Chung-Hang; Ma, Dik-Lung; Wen, Zhi-Hong; Wang, Hui-Min David

    2015-01-01

    Cinnamomum osmophloeum Kanehira belongs to the Lauraceae family of Taiwan's endemic plants. In this study, C. osmophloeum Kanehira extract has shown inhibition of tyrosinase activity on B16-F10 cellular system first. Whether extracts inhibited mushroom tyrosinase activity was tested, and a considerable inhibition of mushroom tyrosinase activity by in vitro assays was presented. Animal experiments of C. osmophloeum Kanehira were carried out by observing animal wound repair, and the extracts had greater wound healing power than the vehicle control group (petroleum jelly with 8% DMSO, w/v). In addition, the antioxidant capacity of C. osmophloeum Kanehira extracts in vitro was evaluated. We measured C. osmophloeum Kanehira extract's free radical scavenging capability, metal chelating, and reduction power, such as biochemical activity analysis. The results showed that a high concentration of C. osmophloeum Kanehira extract had a significant scavenging capability of free radical, a minor effect of chelating ability, and moderate reducing power. Further exploration of the possible physiological mechanisms and the ingredient components of skincare product for skin-whitening, wound repair, or antioxidative agents are to be done. PMID:25839053

  18. Commercial Origanum compactum Benth. and Cinnamomum zeylanicum Blume essential oils against natural mycoflora in Valencia rice.

    PubMed

    Santamarina, M Pilar; Rosell, Josefa; Sempere, Francisca; Gimnez, Silvia; Blzquez, M Amparo

    2015-01-01

    Chemical composition of commercial Origanum compactum and Cinnamomum zeylanicum essential oils and the antifungal activity against pathogenic fungi isolated from Mediterranean rice grains have been investigated. Sixty-one compounds accounting for more than 99.5% of the total essential oil were identified by using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Carvacrol (43.26%), thymol (21.64%) and their biogenetic precursors p-cymene (13.95%) and ?-terpinene (11.28%) were the main compounds in oregano essential oil, while the phenylpropanoids, eugenol (62.75%), eugenol acetate (16.36%) and (E)-cinnamyl acetate (6.65%) were found in cinnamon essential oil. Both essential oils at 300 ?g/mL showed antifungal activity against all tested strains. O. compactum essential oil showed the best antifungal activity towards Fusarium species and Bipolaris oryzae with a total inhibition of the mycelial growth. In inoculated rice grains at lower doses (100 and 200 ?g/mL) significantly reduced the fungal infection, so O. compactum essential oil could be used as ecofriendly preservative for field and stored Valencia rice. PMID:25612221

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

    PubMed

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

    2010-01-01

    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

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

    PubMed

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

    2012-04-01

    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

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

    TOXLINE Toxicology Bibliographic Information

    Mateos-Martín ML; Pérez-Jiménez J; Fuguet E; Torres JL

    2012-04-01

    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.

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

    PubMed Central

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

    2014-01-01

    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. PMID:25183332

  3. Subcritical water extraction of flavoring and phenolic compounds from cinnamon bark (Cinnamomum zeylanicum).

    PubMed

    Khuwijitjaru, Pramote; Sayputikasikorn, Nucha; Samuhasaneetoo, Suched; Penroj, Parinda; Siriwongwilaichat, Prasong; Adachi, Shuji

    2012-01-01

    Cinnamon bark (Cinnamomum zeylanicum) powder was treated with subcritical water at 150 and 200C in a semi-continuous system at a constant flow rate (3 mL/min) and pressure (6 MPa). Major flavoring compounds, i.e., cinnamaldehyde, cinnamic acid, cinnamyl alcohol and coumarin, were extracted at lower recoveries than the extraction using methanol, suggesting that degradation of these components might occur during the subcritical water treatment. Caffeic, ferulic, p-coumaric, protocatechuic and vanillic acids were identified from the subcritical water treatment. Extraction using subcritical water was more effective to obtain these acids than methanol (50% v/v) in both number of components and recovery, especially at 200C. Subcritical water treatment at 200C also resulted in a higher total phenolic content and DPPH radical scavenging activity than the methanol extraction. The DPPH radical scavenging activity and total phenolic content linearly correlated but the results suggested that the extraction at 200C might result in other products that possessed a free radical scavenging activity other than the phenolic compounds. PMID:22687781

  4. Evaluation of Cinnamomum osmophloeum Kanehira extracts on tyrosinase suppressor, wound repair promoter, and antioxidant.

    PubMed

    Lee, Man-Gang; Kuo, Su-Yu; Yen, Shih-Yu; Hsu, Hsia-Fen; Leung, Chung-Hang; Ma, Dik-Lung; Wen, Zhi-Hong; Wang, Hui-Min David

    2015-01-01

    Cinnamomum osmophloeum Kanehira belongs to the Lauraceae family of Taiwan's endemic plants. In this study, C. osmophloeum Kanehira extract has shown inhibition of tyrosinase activity on B16-F10 cellular system first. Whether extracts inhibited mushroom tyrosinase activity was tested, and a considerable inhibition of mushroom tyrosinase activity by in vitro assays was presented. Animal experiments of C. osmophloeum Kanehira were carried out by observing animal wound repair, and the extracts had greater wound healing power than the vehicle control group (petroleum jelly with 8% DMSO, w/v). In addition, the antioxidant capacity of C. osmophloeum Kanehira extracts in vitro was evaluated. We measured C. osmophloeum Kanehira extract's free radical scavenging capability, metal chelating, and reduction power, such as biochemical activity analysis. The results showed that a high concentration of C. osmophloeum Kanehira extract had a significant scavenging capability of free radical, a minor effect of chelating ability, and moderate reducing power. Further exploration of the possible physiological mechanisms and the ingredient components of skincare product for skin-whitening, wound repair, or antioxidative agents are to be done. PMID:25839053

  5. Antibacterial activity of leaf essential oils and their constituents from Cinnamomum osmophloeum.

    PubMed

    Chang, S T; Chen, P F; Chang, S C

    2001-09-01

    The antibacterial activities of the essential oils from leaves of two Cinnamomum osmophloeum clones (A and B) and their chemical constituents were investigated in this study. The nine strains of bacteria, including Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae, Salmonella sp., and Vibrio parahemolyticus, were used in the antibacterial tests. Results from the antibacterial tests demonstrated that the indigenous cinnamon B leaf essential oils had an excellent inhibitory effect. The MICs (minimum inhibitory concentrations) of the B leaf oil were 500 microg/ml against both K. pneumoniae and Salmonella sp. and 250 microg/ml against the other seven strains of bacteria. Cinnamaldehyde possessed the strongest antibacterial activity compared to the other constituents of the essential oils. The MICs of cinnamaldehyde against the E. coli, P. aeruginosa, E. faecalis, S. aureus, S. epidermidis, MRSA, K. pneumoniae, Salmonella sp., and V. parahemolyticus were 500, 1000, 250, 250, 250, 250, 1000, 500, and 250 microg/ml, respectively. These results suggest that C. osmophloeum leaf essential oil and cinnamaldehyde are beneficial to human health, having the potential to be used for medical purposes and to be utilized as anti-bacterial additives in making paper products. PMID:11483389

  6. Seedling Disease Survey in Michigan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stand establishment and persistence continue to be problems for Michigan growers. To determine the extent and severity of the problem, a survey of diseased seedlings from Michigan fields was initiated in 2008. Samples were collected of diseased seedlings for two years. In 2008, samples were collecte...

  7. Anti-inflammation activity of fruit essential oil from Cinnamomum insularimontanum Hayata.

    PubMed

    Lin, Chien-Tsong; Chen, Chi-Jung; Lin, Ting-Yu; Tung, Judia Chen; Wang, Sheng-Yang

    2008-12-01

    In this study, the fruit essential oil of Cinnamomum insularimontanum was prepared by using water distillation. Followed by GC-MS analysis, the composition of fruit essential oil was characterized. The main constituents of essential oil were alpha-pinene (9.45%), camphene (1.70%), beta-pinene (4.30%), limonene (1.76%), citronellal (24.64%), citronellol (16.78%), and citral (35.89%). According to the results obtained from nitric oxide (NO) inhibitory activity assay, crude essential oil and its dominant compound (citral) presented the significant NO production inhibitory activity, IC(50) of crude essential oil and citral were 18.68 and 13.18microg/mL, respectively. Moreover, based on the results obtained from the protein expression assay, the expression of IKK, iNOS, and nuclear NF-kappaB was decreased and IkappaBalpha was increased in dose-dependent manners, it proved that the anti-inflammatory mechanism of citral was blocked via the NF-kappaB pathway, but it could not efficiently suppress the activity on COX-2. In addition, citral exhibited a potent anti-inflammatory activity in the assay of croton oil-induced mice ear edema, when the dosage was 0.1 and 0.3mg per ear, the inflammation would reduce to 22% and 83%, respectively. The results presented that the fruit essential oil of C. insularimontanum and/or citral may have a great potential to develop the anti-inflammatory medicine in the future. PMID:18513962

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

    PubMed

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

    2013-09-01

    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 120gpot(-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: 40gpot(-1)>A2: 80gpot(-1)>A3: 120gpot(-1)>CK: 0gpot(-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

  9. Antibacterial activity of leaf essential oil and its constituents from Cinnamomum longepaniculatum.

    PubMed

    Li, Li; Li, Zheng-Wen; Yin, Zhong-Qiong; Wei, Qin; Jia, Ren-Yong; Zhou, Li-Jun; Xu, Jiao; Song, Xu; Zhou, Yi; Du, Yong-Hua; Peng, Lian-Ci; Kang, Shuai; Yu, Wang

    2014-01-01

    Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Salmonella enteritidis CMCC (B) 50041, were used in the antibacterial tests of Cinnamomum longepaniculatum leaf essential oil and its five chemical constituents. The effect of 1, 8-cineole on the ultrastructural structure of the bacteria (S. aureus and E. coli) was also investigated by transmission electron microscopy. The C. longepaniculatum leaf essential oil and the five chemical constituents showed variable levels of inhibition. Their MIC ( minimum inhibitory concentration ) and MBC (minimal bacteriocidal concentration) values were all in the range of 0.781 L/mL~6.25 L/mL and 0.781 L/mL~12.5 L/mL respectively except ?-terpinene. The MIC values of ?-terpinene against E. coli and S. aureus were all higher than 50 L/mL, but the MIC and MBC values of ?-terpinene against S. enteritidis was only 3.125 L/mL. Among them, ?-terpineol possessed the best antibacterial activity. Under the transmission electron microscope, cell size of treated E. coli decreased, cell wall and cell membrane ruptured, and nucleoplasm was reduced and gathered onto the side. After the S. aureus was treated with 1, 8-cineole, the cell size and shape were damaged and nucleus cytoplasm was concentrated or reduced or agglomerated on the side. These results suggest that C. longepaniculatum leaf essential oil and its constituents have excellent antibacterial activities, the antibacterial mechanism of 1, 8-cineole against E. coli and S. aureus might attributable to its hydrophobicity. PMID:25126170

  10. Antibacterial activity of leaf essential oil and its constituents from Cinnamomum longepaniculatum

    PubMed Central

    Li, Li; Li, Zheng-Wen; Yin, Zhong-Qiong; Wei, Qin; Jia, Ren-Yong; Zhou, Li-Jun; Xu, Jiao; Song, Xu; Zhou, Yi; Du, Yong-Hua; Peng, Lian-Ci; Kang, Shuai; Yu, Wang

    2014-01-01

    Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Salmonella enteritidis CMCC (B) 50041, were used in the antibacterial tests of Cinnamomum longepaniculatum leaf essential oil and its five chemical constituents. The effect of 1, 8-cineole on the ultrastructural structure of the bacteria (S. aureus and E. coli) was also investigated by transmission electron microscopy. The C. longepaniculatum leaf essential oil and the five chemical constituents showed variable levels of inhibition. Their MIC ( minimum inhibitory concentration ) and MBC (minimal bacteriocidal concentration) values were all in the range of 0.781 L/mL~6.25 L/mL and 0.781 L/mL~12.5 L/mL respectively except ?-terpinene. The MIC values of ?-terpinene against E. coli and S. aureus were all higher than 50 L/mL, but the MIC and MBC values of ?-terpinene against S. enteritidis was only 3.125 L/mL. Among them, ?-terpineol possessed the best antibacterial activity. Under the transmission electron microscope, cell size of treated E. coli decreased, cell wall and cell membrane ruptured, and nucleoplasm was reduced and gathered onto the side. After the S. aureus was treated with 1, 8-cineole, the cell size and shape were damaged and nucleus cytoplasm was concentrated or reduced or agglomerated on the side. These results suggest that C. longepaniculatum leaf essential oil and its constituents have excellent antibacterial activities, the antibacterial mechanism of 1, 8-cineole against E. coli and S. aureus might attributable to its hydrophobicity. PMID:25126170

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

    PubMed Central

    2014-01-01

    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 μg/ml in the laboratory while in semi-field environments it was 11.91 to 63.63 μg/ml. The LC90 value was found to range between 57.71 to 91.54 μg/ml in the laboratory while in semi-field environments was 52.07 to 173.77 μg/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. PMID:24885613

  12. The Effects of Cinnamomum Cassia on Blood Glucose Values are Greater than those of Dietary Changes Alone

    PubMed Central

    Hoehn, Ashley N.; Stockert, Amy L.

    2012-01-01

    Eighteen type II diabetics (9 women and 9 men) participated in a 12-week trial that consisted of 2 parts, a 3-week control phase followed by a 9-week experimental phase where half of the subjects received 1000 mg of Cinnamomum cassia while the other half received 1000 mg of a placebo pill. All of the subjects that were in the cinnamon group had a statistically significant decrease in their blood sugar levels with a P-value of 3.915 × 10−10. The subjects in the cinnamon group had an average overall decrease in their blood sugar levels of about 30 mg/dL, which is comparable to oral medications available for diabetes. All subjects were educated on appropriate diabetic diets and maintained that diet for the entire 12 week study. Greater decreases in blood glucose values were observed in patients using the cinnamon compared to those using the dietary changes alone. PMID:23882151

  13. Beet Rust and Seedling Rust

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beet rust, caused by Uromyces betae, can cause pustules on most beet types, and can be a problem in various beet growing areas. Seedling rust, caused by Puccinia subnitens can cause lesions on young beets, primarily on cotyledons, and does not cause economic damage. This chapter describes the dise...

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

    PubMed Central

    2013-01-01

    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 tissues 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. PMID:23368533

  15. ESTABLISHMENT AND SEEDLING GROWTH OF BIG BLUESTEM AND SWITCHGRASS POPULATIONS DIVERGENTLY SELECTED FOR SEEDLING TILLER NUMBER.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selection at the seedling stage in grass breeding would be extremely useful if seedling traits are correlated to desired agronomic traits. The objective of this study was to evaluate seedling morphological development, plant growth, and field establishment of big bluestem (Andropogon gerardii Vitma...

  16. Anthelmintic activity of trans-cinnamaldehyde and A- and B-type proanthocyanidins derived from cinnamon (Cinnamomum verum)

    PubMed Central

    Williams, Andrew R.; Ramsay, Aina; Hansen, Tina V. A.; Ropiak, Honorata M.; Mejer, Helena; Nejsum, Peter; Mueller-Harvey, Irene; Thamsborg, Stig M.

    2015-01-01

    Cinnamon (Cinnamomum verum) has been shown to have anti-inflammatory and antimicrobial properties, but effects on parasitic worms of the intestine have not been investigated. Here, extracts of cinnamon bark were shown to have potent in vitro anthelmintic properties against the swine nematode Ascaris suum. Analysis of the extract revealed high concentrations of proanthocyanidins (PAC) and trans-cinnamaldehyde (CA). The PAC were subjected to thiolysis and HPLC-MS analysis which demonstrated that they were exclusively procyanidins, had a mean degree of polymerization of 5.2 and 21% of their inter-flavan-3-ol links were A-type linkages. Purification of the PAC revealed that whilst they had activity against A. suum, most of the potency of the extract derived from CA. Trichuris suis and Oesophagostomum dentatum larvae were similarly susceptible to CA. To test whether CA could reduce A. suum infection in pigs in vivo, CA was administered daily in the diet or as a targeted, encapsulated dose. However, infection was not significantly reduced. It is proposed that the rapid absorption or metabolism of CA in vivo may prevent it from being present in sufficient concentrations in situ to exert efficacy. Therefore, further work should focus on whether formulation of CA can enhance its activity against internal parasites. PMID:26420588

  17. Evaluation of anxiolytic potency of essential oil and S-(+)-linalool from Cinnamomum osmophloeum ct. linalool leaves in mice.

    PubMed

    Cheng, Bing-Ho; Sheen, Lee-Yan; Chang, Shang-Tzen

    2015-01-01

    Cinnamomum osmophloeum ct. linalool ( t? ru gu) is one chemotype of the indigenous cinnamons in Taiwan. This study examined the anxiolytic potency of leaf essential oil (LEO) from C.osmophloeum ct. linalool and its main constituent on 4-week ICR mice using an open field test (OFT), a light-dark test (LDT) and an elevated plus maze test (EPT). After oral administration of corn oil, LEO (250mg/kg and 500mg/kg), S-(+)-linalool (500mg/kg), R-(-)-linalool (500mg/kg), and trazodone hydrochloride (75mg/kg) for 14 days, the anxiolytic effects on mice behavior were evaluated. The results showed that LEO from C.osmophloeum ct. linalool leaves and S-(+)-linalool can significantly increase the time mice remained in the center area of the OFT, the illuminated area of the LDT and the open arms of the EPT without any side effects affecting motor activity, indicating excellent anxiolytic responses. Furthermore, results from the measurements of monoamines in mice brain revealed decreases in serotonin, dopamine, and norepinephrine, which are consistent with their anxiolytic effects in animal models. The findings obtained suggest that LEO from C.osmophloeum ct. linalool and its major compound, S-(+)-linalool, possess anxiolytic properties without any side effects and thus support their potential use in treatment of anxiety disorders. PMID:26151006

  18. Evaluation of anxiolytic potency of essential oil and S-(+)-linalool from Cinnamomum osmophloeum ct. linalool leaves in mice

    PubMed Central

    Cheng, Bing-Ho; Sheen, Lee-Yan; Chang, Shang-Tzen

    2014-01-01

    Cinnamomum osmophloeum ct. linalool (??? t? ru gu) is one chemotype of the indigenous cinnamons in Taiwan. This study examined the anxiolytic potency of leaf essential oil (LEO) from C.osmophloeum ct. linalool and its main constituent on 4-week ICR mice using an open field test (OFT), a lightdark test (LDT) and an elevated plus maze test (EPT). After oral administration of corn oil, LEO (250mg/kg and 500mg/kg), S-(+)-linalool (500mg/kg), R-(?)-linalool (500mg/kg), and trazodone hydrochloride (75mg/kg) for 14 days, the anxiolytic effects on mice behavior were evaluated. The results showed that LEO from C.osmophloeum ct. linalool leaves and S-(+)-linalool can significantly increase the time mice remained in the center area of the OFT, the illuminated area of the LDT and the open arms of the EPT without any side effects affecting motor activity, indicating excellent anxiolytic responses. Furthermore, results from the measurements of monoamines in mice brain revealed decreases in serotonin, dopamine, and norepinephrine, which are consistent with their anxiolytic effects in animal models. The findings obtained suggest that LEO from C.osmophloeum ct. linalool and its major compound, S-(+)-linalool, possess anxiolytic properties without any side effects and thus support their potential use in treatment of anxiety disorders. PMID:26151006

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

    PubMed

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

    2011-03-01

    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

  20. Effect of cinnamomum zeylanicum blume essential oil on the growth and morphogenesis of some potentially pathogenic Aspergillus species

    PubMed Central

    Carmo, Egberto Santos; de Oliveira Lima, Edeltrudes; de Souza, Evandro Leite; de Sousa, Frederico Barbosa

    2008-01-01

    Cinnamomum zeylanicum Blume is known for a wide range of medicinal properties. This study aimed to assess the interference of C. zeylanicum essential oil on the growth and morphogenesis of some potentially pathogenic Aspergillus species. The essential oil presented strong antifungal effect causing the growth inhibition of the assayed strains and development of large growth inhibition zones. MIC50 and MIC90 values were 40 and 80 μL/mL, respectively. 80, 40 and 20 μL/mL of the oil strongly inhibited the radial mycelial growth of A. niger, A. flavus and A. fumigatus along 14 days. 80 and 40 μL/mL of the oil caused a 100% inhibition of the fungal spore germination. Main morphological changes observed under light microscopy provided by the essential oil in the fungal strains were decreased conidiation, leakage of cytoplasm, loss of pigmentation and disrupted cell structure indicating fungal wall degeneration. It is concluded that C. zeylanicum essential oil could be known as potential antifungal compound, particularly, to protect against the growth of Aspergillus species. PMID:24031186

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

    PubMed

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

    2012-01-01

    Plantbased 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

  2. Ethanol extracts of Cinnamomum kanehirai Hayata leaves induce apoptosis in human hepatoma cell through caspase-3 cascade

    PubMed Central

    Liu, Yu-Kuo; Chen, Kuan-Hsing; Leu, Yann-Lii; Way, Tzong-Der; Wang, Ling-Wei; Chen, Yu-Jen; Liu, Yu-Ming

    2015-01-01

    Inducing apoptosis to susceptible cells is the major mechanism of most cytotoxic anticancer drugs in current use. Cinnamomum kanehirai Hayata (Lauraceae), a unique and native tree of Taiwan, is the major host for the medicinal fungus Antrodia cinnamomea which exhibits anti-cancer activity. Because of the scarcity of A. cinnamomea, C. kanehirai Hayata instead, is used as fork medicine in liver cancer. Here we observed the C. kanehirai Hayata ethanol extract could inhibit the cellular viability of both HepG2 and HA22T/VGH human hepatoma cell lines in a dose- and time-dependent manner. We found the mode of cell death was apoptosis according to cell morphological changes by Liu’s stain, oligonucleosomal DNA fragmentation by gel electrophoresis, externalization of phosphotidyl serine by detecting Annexin V and hypoploid population by cell cycle analysis. Our results showed that the extracts caused cleavage of caspase-3 and increased enzyme activity of caspase-8 and caspase-9. Caspase 3 inhibitor partially reversed the viability inhibition by the extract. Furthermore, the up-regulation of Bax and down-regulation of Bcl-2 were also noted by the extract treatment. In conclusion, C. kanehirai Hayata ethanol extract induced intrinsic pathway of apoptosis through caspase-3 cascade in human hepatoma HA22T/VGH and HepG2 cells, which might shed new light on hepatoma therapy. PMID:25678797

  3. In Vitro Antiviral Activity of Cinnamomum cassia and Its Nanoparticles Against H7N3 Influenza A Virus.

    PubMed

    Fatima, Munazza; Zaidi, Najam-Us-Sahar Sadaf; Amraiz, Deeba; Afzal, Farhan

    2016-01-28

    Nanoparticles have wide-scale applications in various areas, including medicine, chemistry, electronics, and energy generation. Several physical, biological, and chemical methods have been used for synthesis of silver nanoparticles. Green synthesis of silver nanoparticles using plants provide advantages over other methods as it is easy, efficient, and eco-friendly. Nanoparticles have been extensively studied as potential antimicrobials to target pathogenic and multidrug-resistant microorganisms. Their applications recently extended to development of antivirals to inhibit viral infections. In this study, we synthesized silver nanoparticles using Cinnamomum cassia (Cinnamon) and evaluated their activity against highly pathogenic avian influenza virus subtype H7N3. The synthesized nanoparticles were characterized using UVVis absorption spectroscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy. Cinnamon bark extract and its nanoparticles were tested against H7N3 influenza A virus in Vero cells and the viability of cells was determined by tetrazolium dye (MTT) assay. The silver nanoparticles derived from Cinnamon extract enhanced the antiviral activity and were found to be effective in both treatments, when incubated with the virus prior to infection and introduced to cells after infection. In order to establish the safety profile, Cinnamon and its corresponding nanoparticles were tested for their cytotoxic effects in Vero cells. The tested concentrations of extract and nanoparticles (up to 500 ?g/ml) were found non-toxic to Vero cells. The biosynthesized nanoparticles may, hence, be a promising approach to provide treatment against influenza virus infections. PMID:26403820

  4. Anthelmintic activity of trans-cinnamaldehyde and A- and B-type proanthocyanidins derived from cinnamon (Cinnamomum verum).

    PubMed

    Williams, Andrew R; Ramsay, Aina; Hansen, Tina V A; Ropiak, Honorata M; Mejer, Helena; Nejsum, Peter; Mueller-Harvey, Irene; Thamsborg, Stig M

    2015-01-01

    Cinnamon (Cinnamomum verum) has been shown to have anti-inflammatory and antimicrobial properties, but effects on parasitic worms of the intestine have not been investigated. Here, extracts of cinnamon bark were shown to have potent in vitro anthelmintic properties against the swine nematode Ascaris suum. Analysis of the extract revealed high concentrations of proanthocyanidins (PAC) and trans-cinnamaldehyde (CA). The PAC were subjected to thiolysis and HPLC-MS analysis which demonstrated that they were exclusively procyanidins, had a mean degree of polymerization of 5.2 and 21% of their inter-flavan-3-ol links were A-type linkages. Purification of the PAC revealed that whilst they had activity against A. suum, most of the potency of the extract derived from CA. Trichuris suis and Oesophagostomum dentatum larvae were similarly susceptible to CA. To test whether CA could reduce A. suum infection in pigs in vivo, CA was administered daily in the diet or as a targeted, encapsulated dose. However, infection was not significantly reduced. It is proposed that the rapid absorption or metabolism of CA in vivo may prevent it from being present in sufficient concentrations in situ to exert efficacy. Therefore, further work should focus on whether formulation of CA can enhance its activity against internal parasites. PMID:26420588

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

    PubMed

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

    2013-01-01

    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

  6. The effect of Cinnamomum zeylanicum essential oil on chemical characteristics of Lyoner- type sausage during refrigerated storage

    PubMed Central

    Aminzare, Majid; Aliakbarlu, Javad; Tajik, Hossein

    2015-01-01

    The effect of Cinnamomum zeylanicum essential oil (CZEO) at two concentrations (0.02% and 0.04% v/w) on chemical composition, pH, water activity (aw), lipid oxidation, color stability and sensory characteristics of Lyoner-type sausage stored at 4 ˚C for 40 days was investigated. The moisture content of the control sample was higher (p < 0.05) than CZEO incorporated samples, while fat, ash and protein content were not affected by adding essential oil. At days 0 and 40, Lightness (L*) and whiteness index (WI) were significantly decreased and total color difference (ΔE) significantly increased (p < 0.05) by adding CZEO. With the exception of first day of storage, redness (a*) and yellowness (b*) were significantly increased and decreased, respectively during the rest of storage (p < 0.05). The pH values were not differing between the control samples and samples containing CZEO (p > 0.05). The water activity content fell in Lyoners with added CZEO during the storage. Incorporation of CZEO retard lipid oxidation process at the end of storage (p < 0.05). Samples containing highest amount of CZEO had higher sensory score compared to control sample. Our results pointed out that CZEO could be used as natural additive for increasing the chemical stability of Lyoner-type sausages. PMID:25992249

  7. Verification of the antidiabetic effects of cinnamon (Cinnamomum zeylanicum) using insulin-uncontrolled type 1 diabetic rats and cultured adipocytes.

    PubMed

    Shen, Yan; Fukushima, Misato; Ito, Yoshimasa; Muraki, Etsuko; Hosono, Takashi; Seki, Taiichiro; Ariga, Toyohiko

    2010-01-01

    It has long been believed that an intake of cinnamon (Cinnamomum zeylanicum) alleviates diabetic pathological conditions. However, it is still controversial whether the beneficial effect is insulin-dependent or insulin-mimetic. This study was aimed at determining the insulin-independent effect of cinnamon. Streptozotocin-induced diabetic rats were divided into four groups and orally administered with an aqueous cinnamon extract (CE) for 22 d. The diabetic rats that had taken CE at a dose of more than 30 mg/kg/d were rescued from their hyperglycemia and nephropathy, and these rats were found to have upregulation of uncoupling protein-1 (UCP-1) and glucose transporter 4 (GLUT4) in their brown adipose tissues as well as in their muscles. This was verified by using 3T3-L1 adipocytes in which CE upregulates GLUT4 translocation and increases the glucose uptake. CE exhibited its anti-diabetic effect independently from insulin by at least two mechanisms: i) upregulation of mitochondrial UCP-1, and ii) enhanced translocation of GLUT4 in the muscle and adipose tissues. PMID:21150113

  8. Ethanol extracts of Cinnamomum kanehirai Hayata leaves induce apoptosis in human hepatoma cell through caspase-3 cascade.

    PubMed

    Liu, Yu-Kuo; Chen, Kuan-Hsing; Leu, Yann-Lii; Way, Tzong-Der; Wang, Ling-Wei; Chen, Yu-Jen; Liu, Yu-Ming

    2015-01-01

    Inducing apoptosis to susceptible cells is the major mechanism of most cytotoxic anticancer drugs in current use. Cinnamomum kanehirai Hayata (Lauraceae), a unique and native tree of Taiwan, is the major host for the medicinal fungus Antrodia cinnamomea which exhibits anti-cancer activity. Because of the scarcity of A. cinnamomea, C. kanehirai Hayata instead, is used as fork medicine in liver cancer. Here we observed the C. kanehirai Hayata ethanol extract could inhibit the cellular viability of both HepG2 and HA22T/VGH human hepatoma cell lines in a dose- and time-dependent manner. We found the mode of cell death was apoptosis according to cell morphological changes by Liu's stain, oligonucleosomal DNA fragmentation by gel electrophoresis, externalization of phosphotidyl serine by detecting Annexin V and hypoploid population by cell cycle analysis. Our results showed that the extracts caused cleavage of caspase-3 and increased enzyme activity of caspase-8 and caspase-9. Caspase 3 inhibitor partially reversed the viability inhibition by the extract. Furthermore, the up-regulation of Bax and down-regulation of Bcl-2 were also noted by the extract treatment. In conclusion, C. kanehirai Hayata ethanol extract induced intrinsic pathway of apoptosis through caspase-3 cascade in human hepatoma HA22T/VGH and HepG2 cells, which might shed new light on hepatoma therapy. PMID:25678797

  9. Hordeum vulgare Seedlings Amine Oxidase

    PubMed Central

    Cogoni, Antonina; Piras, Carla; Farci, Raffaele; Melis, Antonello; Floris, Giovanni

    1990-01-01

    Although no amine oxidase could be detected in crude extracts, the enzyme has been purified to apparent homogeneity from Hordeum vulgare seedlings using ammonium sulfate precipitation and chromatography on DEAE cellulose, Hydroxylapatite, and Sephadex G200 columns. Gel filtration experiments indicate a molecular weight of about 150,000. The pH optimum of the enzyme was found to be 7.5 in potassium phosphate buffer. The spectrum of ultraviolet and visible regions were similar to Cuamine oxidase from Leguminosae. PMID:16667542

  10. Field measurement of cotton seedling evapotranspiration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Information on cotton evapotranspiration (ET) during the seedling growth stage and under field conditions is scarce because ET is a difficult parameter to measure. Our objective was to use weighable lysimeters to measure daily values of cotton seedling ET. We designed and built plastic weighable mic...

  11. Efficacy and safety of 'true' cinnamon (Cinnamomum zeylanicum) as a pharmaceutical agent in diabetes: a systematic review and meta-analysis.

    TOXLINE Toxicology Bibliographic Information

    Ranasinghe P; Jayawardana R; Galappaththy P; Constantine GR; de Vas Gunawardana N; Katulanda P

    2012-12-01

    AIMS: Diabetes is a leading cause of morbidity and mortality worldwide. Studies have frequently looked at dietary components beneficial in treatment and prevention. We aim to systematically evaluate the literature on the safety and efficacy of Cinnamomum zeylanicum on diabetes.METHODS: A comprehensive search of the literature was conducted in the following databases; PubMed, Web of Science, Biological Abstracts, SciVerse Scopus, SciVerse ScienceDierect, CINAHL and The Cochrane Library. A meta-analysis of studies examining the effect of C. zeylanicum extracts on clinical and biochemical parameters was conducted. Data were analysed using RevMan v5.1.2.RESULTS: The literature search identified 16 studies on C. zeylanicum (five in-vitro, six in-vivo and five in-vivo/in-vitro). However, there were no human studies. In-vitro C. zeylanicum demonstrated a potential for reducing post-prandial intestinal glucose absorption by inhibiting pancreatic α-amylase and α-glucosidase, stimulating cellular glucose uptake by membrane translocation of glucose transporter-4, stimulating glucose metabolism and glycogen synthesis, inhibiting gluconeogenesis and stimulating insulin release and potentiating insulin receptor activity. The beneficial effects of C. zeylanicum in animals include attenuation of diabetes associated weight loss, reduction of fasting blood glucose, LDL and HbA(1c) , increasing HDL cholesterol and increasing circulating insulin levels. Cinnamomum zeylanicum also significantly improved metabolic derangements associated with insulin resistance. It also showed beneficial effects against diabetic neuropathy and nephropathy, with no significant toxic effects on liver and kidney and a significantly high therapeutic window.CONCLUSION: Cinnamomum zeylanicum demonstrates numerous beneficial effects both in vitro and in vivo as a potential therapeutic agent for diabetes. However, further randomized clinical trials are required to establish therapeutic safety and efficacy.

  12. Pressurized liquid extraction and GC-MS analysis for simultaneous determination of seven components in Cinnamomum cassia and the effect of sample preparation.

    PubMed

    Lv, Guang-Ping; Huang, Wei-Hua; Yang, Feng-Qing; Li, Jing; Li, Shao-Ping

    2010-08-01

    A pressurized liquid extraction and GC-MS method was developed for simultaneous quantitative determination of the seven components, including cinnamaldehyde, copaene, cinnamic acid, coumarin, 2-methoxycinnamaldehyde, 2-methoxycinnamic acid and safrole in Cinnamomum cassia. The results showed that methanol and ethanol was not available for extraction of cinnamaldehyde and 2-methoxycinnamaldehyde due to aldol reaction. The developed method was validated to be sensitive, accurate and simple, and was successfully employed for the analysis of 15 samples of C. cassia. The contents of the investigated components were significantly variant and cinnamaldehyde is the most abundant compound, but safrole was not detected in all samples. PMID:20572266

  13. Protein tyrosine phosphatase 1B inhibitory activity of Indonesian herbal medicines and constituents of Cinnamomum burmannii and Zingiber aromaticum.

    PubMed

    Saifudin, Azis; Kadota, Shigetoshi; Tezuka, Yasuhiro

    2013-04-01

    We screened water and methanol extracts of 28 Indonesian medicinal plants for their protein tyrosine phosphatase 1B (PTP1B) inhibitory activities. Nine water extracts, i.e., Alstonia scholaris leaf, Blumea balsamifera, Cinnamomum burmannii, Cymbopogon nardus, Melaleuca leucadendra, Phyllanthus niruri, Piper nigrum, Syzygium aromaticum, and Sy. polyanthum, exhibited ?70% inhibition at 25?g/mL, whereas 11 methanol extracts, i.e., Als. scholaris, Andrographis paniculata, B. balsamifera, Ci. burmannii, Curcuma heyneana, Glycyrrhiza glabra, M. leucadendra, Punica granatum, Rheum palmatum, Sy. polyanthum, and Z. aromaticum, exhibited ?70% inhibition at 25?g/mL. Water extracts of B. balsamifera (IC50, 2.26?g/mL) and M. leucadendra (IC50, 2.05?g/mL), and methanol extracts of Ci. burmannii (IC50, 2.47?g/mL), Pu. granatum (IC50, 2.40?g/mL), and Sy. polyanthum (IC50, 1.03?g/mL) exhibited strong inhibitory activity, which was comparable with that of the positive control, RK-682 (IC50, 2.05?g/mL). The PTP1B inhibitory activity of the constituents of Ci. burmannii and Z. aromaticum was then evaluated. 5'-Hydroxy-5-hydroxymethyl-4?,5?-methylenedioxy-1,2,3,4-dibenzo-1,3,5-cycloheptatriene (2; IC50, 29.7?M) and trans-cinnamaldehyde (5; IC50, 57.6?M) were the active constituents of Ci. burmannii, while humulatrien-5-ol-8-one (21; IC50, 27.7?M), kaempferol-3,4'-di-O-methyl ether (32; IC50, 17.5?M), and (S)-6-gingerol (33; IC50, 28.1?M) were those of Z. aromaticum. These results suggest that these medicinal plants may contribute to the treatment and/or prevention of type II diabetes and/or obesity through PTP1B inhibition. PMID:22645080

  14. Evaluation of Ethanol and Aqueous extracts of Cinnamomum verum Leaf Galls for Potential Antioxidant and Analgesic activity

    PubMed Central

    Pandey, Minakshi; Chandra, D. R.

    2015-01-01

    In the present study, ethanol and aqueous extracts of leaf galls of Cinnamomum verum were prepared to evaluate the antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl free radical scavenging assay and superoxide radical scavenging assay with ascorbic acid as a standard, and analgesic activity by tail immersion test and acetic acid-induced writhing test methods using diclofenac sodium as the reference drug. Swiss albino mice maintained under standard laboratory conditions were used for analgesic tests. In the 2,2-diphenyl-1-picrylhydrazyl assay it was found that the aqueous and the ethanol extract possessed almost equal capacity to inhibit free radicals (IC50=13.3 and 13.53 g/ml) but found less than ascorbic acid (IC50=9.96 g/ml). And in superoxide assay the ethanol extract was found to be more potent in scavenging super oxide radicals when compared to ascorbic acid and the aqueous extract (IC50=237.1 and 197.8 g/ml) with the IC50=119.7 g/ml. For analgesic activity, ethanol extract showed the maximum time required for response against thermal stimuli (6.750.47 s) and maximum % of writhing inhibition (44.57%) when compared to aqueous extract (5.250.48 s and 32.61%), whereas diclofenac showed response in 7.250.25 s 67.39% inhibition in tail immersion and writhing tests, respectively. These results demonstrate that the ethanol extracts of leaf galls possessed high antioxidant and analgesic activity. PMID:26009661

  15. Evaluation of Ethanol and Aqueous extracts of Cinnamomum verum Leaf Galls for Potential Antioxidant and Analgesic activity.

    PubMed

    Pandey, Minakshi; Chandra, D R

    2015-01-01

    In the present study, ethanol and aqueous extracts of leaf galls of Cinnamomum verum were prepared to evaluate the antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl free radical scavenging assay and superoxide radical scavenging assay with ascorbic acid as a standard, and analgesic activity by tail immersion test and acetic acid-induced writhing test methods using diclofenac sodium as the reference drug. Swiss albino mice maintained under standard laboratory conditions were used for analgesic tests. In the 2,2-diphenyl-1-picrylhydrazyl assay it was found that the aqueous and the ethanol extract possessed almost equal capacity to inhibit free radicals (IC50=13.3 and 13.53 g/ml) but found less than ascorbic acid (IC50=9.96 g/ml). And in superoxide assay the ethanol extract was found to be more potent in scavenging super oxide radicals when compared to ascorbic acid and the aqueous extract (IC50=237.1 and 197.8 g/ml) with the IC50=119.7 g/ml. For analgesic activity, ethanol extract showed the maximum time required for response against thermal stimuli (6.750.47 s) and maximum % of writhing inhibition (44.57%) when compared to aqueous extract (5.250.48 s and 32.61%), whereas diclofenac showed response in 7.250.25 s 67.39% inhibition in tail immersion and writhing tests, respectively. These results demonstrate that the ethanol extracts of leaf galls possessed high antioxidant and analgesic activity. PMID:26009661

  16. Hypoglycemic activity of a polyphenolic oligomer-rich extract of Cinnamomum parthenoxylon bark in normal and streptozotocin-induced diabetic rats.

    PubMed

    Jia, Q; Liu, X; Wu, X; Wang, R; Hu, X; Li, Y; Huang, C

    2009-08-01

    Cinnamon bark has been reported to be effective in the alleviation of diabetes through its antioxidant and insulin-potentiating activities. The water-soluble polyphenolic oligomers found in cinnamon are thought to be responsible for this biological activity. In this study, the hypoglycemic activity of a polyphenolic oligomer-rich extract from the barks of Cinnamomum parthenoxylon (Jack) Nees was studied in normal, transiently hyperglycemic, and streptozotocin (STZ)-induced diabetic rats. Oral administration of the extract at doses of 100, 200, and 300 mg/kg body wt. caused significant changes in body weight loss and fasting blood glucose levels of normal rats. In STZ-induced diabetic rats, after administration of the extract at doses of 100, 200, and 300 mg/kg body wt. over 14 days, the blood glucose levels were decreased by 11.1%, 22.5%, and 38.7%, respectively, and the plasma insulin levels were significantly increased over pre-treatment levels. In an oral glucose tolerance test, the extract produced a significant decrease in glycemia 90 min after the glucose pulse. These results suggest that Cinnamomum parthenoxylon polyphenolic oligomer-rich extract could be potentially useful for post-prandial hyperglycemia treatment. PMID:19464860

  17. 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...

  18. Line-scan inspection of conifer seedlings

    NASA Astrophysics Data System (ADS)

    Rigney, Michael P.; Kranzler, Glenn A.

    1993-05-01

    Almost two billion conifer seedlings are produced in the U.S. each year to support reforestation efforts. Seedlings are graded manually to improve viability after transplanting. Manual grading is labor-intensive and subject to human variability. Our previous research demonstrated the feasibility of automated tree seedling inspection with machine vision. Here we describe a system based on line-scan imaging, providing a three-fold increase in resolution and inspection rate. A key aspect of the system is automatic recognition of the seedling root collar. Root collar diameter, shoot height, and projected shoot and root areas are measured. Sturdiness ratio and shoot/root ratio are computed. Grade is determined by comparing measured features with pre-defined set points. Seedlings are automatically sorted. The precision of machine vision and manual measurements was determined in tests at a commercial forest nursery. Manual measurements of stem diameter, shoot height, and sturdiness ratio had standard deviations three times those of machine vision measurements. Projected shoot area was highly correlated (r2 equals 0.90) with shoot volume. Projected root area had good correlation (r2 equals 0.80) with root volume. Seedlings were inspected at rates as high as ten per second.

  19. Clinorotation affects soybean seedling morphology

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    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).

  20. Influence of plant-parasitic nematodes on longleaf pine seedlings.

    PubMed

    Ruehle, J L

    1973-01-01

    Seedlings of longleaf pine (Pinus palustris) were grown in 20-cm pots for 5 to 7 months in the greenhouse following inoculation with a high or low level of one of seven species of plant-parasitic nematodes. Belonolaimus longicaudatus and Helicotylenchus dihystera had no effect on seedling growth. High inoculum densities of Hoplolaimus galeatus and Tylenchorhynchus claytoni caused a significant reduction of fresh weight of seedling roots. Root and top weights of seedlings grown in soil infested with Meloidodera floridensis or Pratylenchus brachyurus were significantly less than those of seedlings in noninfested soil. Root growth of seedlings was stimulated by the higher inoculum density of Scutellonema brachyurum. PMID:19319287

  1. Anaerobic metabolism in Brassica seedlings

    NASA Astrophysics Data System (ADS)

    Park, Myoung-Ryoul; Hasenstein, Karl H.

    Germination typically depends on oxidative respiration. The lack of convection under space conditions may create hypoxic or conditions during seed germination. We investigated the effect of reduced oxygen on seed germination and metabolism to understand how metabolic constraints affect seed growth and responsiveness to reorientation. Germination was completely inhibited when seeds were imbibed in the absence of oxygen; germination occurred at 5% oxygen and higher levels. Adding oxygen after 72 h resulted in immediate germination (protrusion of the radicle). Hypoxia typically activates alcohol dehydrogenase (ADH, EC 1.1.1.1) and lactate dehydrogenase (LDH, EC 1.1.1.27) which produce ethanol and/or L-lactate, respectively. We report on the expression of ADH1 and LDH1, and changes in total soluble sugars, starch, pH, and L-lactate in seedlings grown at 28°C in 0, 2.5, 5, 10% and ambient (21%) oxygen conditions as controls. The highest consumption (lowest level) of sugars was seen at 0% oxygen but the lowest level of starch occurred 24 h after imbibition under ambient condition. Expression levels of ADH1 in ambient oxygen condition increased within 24 h but increased threefold under hypoxic conditions; LDH1 increased up to 8-fold under hypoxia compared to controls but ADH1 and LDH1 were less expressed as the oxygen levels increased. The intracellular pH of seeds decreased as the content of L-lactate increased for all oxygen concentrations. These results indicate that germination of Brassica is sensitive to oxygen levels and that oxygen availability during germination is an important factor for metabolic activities. (Supported by NASA grant NNX10AP91G)

  2. Seedling growth and development on space shuttle.

    PubMed

    Cowles, J; LeMay, R; Jahns, G

    1994-11-01

    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. PMID:11540197

  3. Seedling growth and development on space shuttle

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

    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.

  4. Seedling growth and development on space shuttle

    NASA Astrophysics Data System (ADS)

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

    1994-11-01

    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.

  5. Neolignans with a Rare 2-Oxaspiro[4.5]deca-6,9-dien-8-one Motif from the Stem Bark of Cinnamomum subavenium.

    PubMed

    Lai, Yongji; Liu, Tingting; Sa, Rongjian; Wei, Xialan; Xue, Yongbo; Wu, Zhaodi; Luo, Zengwei; Xiang, Ming; Zhang, Yonghui; Yao, Guangmin

    2015-07-24

    Two pairs of racemic spirodienone neolignans with a rare 2-oxaspiro[4.5]deca-6,9-dien-8-one motif, named ()-subaveniumins A (1) and B (2), were isolated from the bark of Cinnamomum subavenium. The chiral separation of the (+)-1, (-)-1, (+)-2, and (-)-2 enantiomers was accomplished via high-performance liquid chromatography on a chiral column. Their structures were elucidated using single-crystal X-ray diffraction and spectroscopic analyses (UV, IR, HRESIMS, and 1D and 2D NMR). The absolute configurations of the enantiomers were determined by comparing the experimental and calculated electronic circular dichroic spectra. The (+)-1, (-)-1, (+)-2, and (-)-2 enantiomers exhibited moderate inhibitory effects against NO production in RAW264.7 mouse macrophages induced by lipopolysaccharide, with IC50 values of 17.9, 5.6, 15.1, and 4.3 ?M, respectively. PMID:26087384

  6. 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...

  7. Cinnamomum cassia Suppresses Caspase-9 through Stimulation of AKT1 in MCF-7 Cells but Not in MDA-MB-231 Cells

    PubMed Central

    Kianpour Rad, Sima; Kanthimathi, M. S.; Abd Malek, Sri Nurestri; Lee, Guan Serm; Looi, Chung Yeng; Wong, Won Fen

    2015-01-01

    Background Cinnamomum cassia bark is a popular culinary spice used for flavoring and in traditional medicine. C. cassia extract (CE) induces apoptosis in many cell lines. In the present study, particular differences in the mechanism of the anti-proliferative property of C. cassia on two breast cancer cell lines, MCF-7 and MDA-MB-231, were elucidated. Methodology/Principal Findings The hexane extract of C. cassia demonstrated high anti-proliferative activity against MCF-7 and MDA-MB-231 cells (IC50, 34±3.52 and 32.42 ±0.37 μg/ml, respectively). Oxidative stress due to disruption of antioxidant enzyme (SOD, GPx and CAT) activity is suggested as the probable cause for apoptosis initiation. Though the main apoptosis pathway in both cell lines was found to be through caspase-8 activation, caspase-9 was also activated in MDA-MB-231 cells but suppressed in MCF-7 cells. Gene expression studies revealed that AKT1, the caspase-9 suppressor, was up-regulated in MCF-7 cells while down-regulated in MDA-MB-231 cells. Although, AKT1 protein expression in both cell lines was down-regulated, a steady increase in MCF-7 cells was observed after a sharp decrease of suppression of AKT1. Trans-cinnamaldehyde and coumarin were isolated and identified and found to be mainly responsible for the observed anti-proliferative activity of CE (Cinnamomum cassia). Conclusion Activation of caspase-8 is reported for the first time to be involved as the main apoptosis pathway in breast cancer cell lines upon treatment with C. cassia. The double effects of C. cassia on AKT1 gene expression in MCF-7 cells is reported for the first time in this study. PMID:26700476

  8. Changes of nucleic acids of wheat seedlings under spaceflight conditions

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

    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.

  9. Seed Mucilage Improves Seedling Emergence of a Sand Desert Shrub

    PubMed Central

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

    2012-01-01

    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. PMID:22511952

  10. Analysis for an environmental friendly seedling breeding system

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    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/m2 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.

  11. Rhizoctonia seedling damping-off in sugar beet in Michigan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia solani is an important seedling pathogen of sugar beet, causing damping-off following seedling emergence. Anastomosis group (AG)-4 has been the primary seedling pathogen reported on sugar beet, however, recent screening has found high incidence of infection by AG-2-2. Isolations of R. so...

  12. Management of seedling damping-off of alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A vigorous and productive alfalfa stand starts with strong and uniform seedling establishment. Seed rot and seedling damping-off are a significant cause of poor stand establishment in wet soils. A number of organisms cause seed rot and seedling damping-off including several species of Pythium. As a ...

  13. GENETIC ANALYSIS OF APHANOMYCES SEEDLING RESISTANCE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aphanomyces seedling disease is one of the causal agents preventing good stand persistence in sugarbeet. Aphanomyces generally becomes more of a problem for growers when plants are four to six weeks old, especially after a heavy rain and in flooded areas of the field. There has been no reliable seed...

  14. Nursery performance of peach seedling rootstocks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The nursery performance of a cross-section of both historically important and current commercial peach [Prunus persica (L.) Batsch] seedling type rootstocks was studied over three growing seasons at six nurseries serving the southeastern US peach industry. Rootstock lines differed significantly in ...

  15. Grass seedling demography and sage steppe restoration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seeding is a key management tool for semi-arid and arid rangeland. In these systems, however, seeded species often fail to establish. The objectives of this study were to identify demographic transitions limiting seedling recruitment in a disturbed, sage steppe system and determine the degree to w...

  16. 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...

  17. Can Seedling Ionomics Predict Rice Grain Ionomics?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The study investigated the possibility of using the mineral (ionomic) composition of rice (Oryza sativa L.) seedling leaves to predict cultivars that accumulate large amounts of certain minerals in their grains. This information will be used for genetically improving the nutritional value of rice gr...

  18. [Amino acid composition of Phaseolus aureus L. seeds and seedlings].

    PubMed

    Min'dyk BuI; Shaposhinkov, G L; Aseeva, K B

    1978-01-01

    The amino acid composition of seeds and 10-day seedlings of mung bean (Phaseolus aureus L.) as well as that of proteins of Ph. aureus seedlings was measured. The seedlings were grown under different conditions of nitrogen nutrition in the light and in the dark. Ph. aureus seeds showed a high content of some essential amino acids. As compared with seeds, the seedlings had higher concentrations of aspartic acid and isoleucine and lower concentrations of glutamic acid, lysine and histidine. Proteins of Ph. aureus seedlings showed greater amounts of isoleucine, phenylalanine, threonine, lysine and lower quantities of glutamic acid. Methionine and cystine were limiting amino acids. PMID:674120

  19. Ethylene-orchestrated circuitry coordinates a seedlings response to soil cover and etiolated growth

    PubMed Central

    Zhong, Shangwei; Shi, Hui; Xue, Chang; Wei, Ning; Guo, Hongwei; Deng, Xing Wang

    2014-01-01

    The early life of terrestrial seed plants often starts under the soil in subterranean darkness. Over time and through adaptation, plants have evolved an elaborate etiolation process that enables seedlings to emerge from soil and acquire autotrophic ability. This process, however, requires seedlings to be able to sense the soil condition and relay this information accordingly to modulate both the seedlings growth and the formation of photosynthetic apparatus. The mechanism by which soil overlay drives morphogenetic changes in plants, however, remains poorly understood, particularly with regard to the means by which the cellular processes of different organs are coordinated in response to disparate soil conditions. Here, we illustrate that the soil overlay quantitatively activates seedlings ethylene production, and an EIN3/EIN3-like 1dependent ethylene-response cascade is required for seedlings to successfully emerge from the soil. Under soil, an ERF1 pathway is activated in the hypocotyl to slow down cell elongation, whereas a PIF3 pathway is activated in the cotyledon to control the preassembly of photosynthetic machinery. Moreover, this latter PIF3 pathway appears to be coupled to the ERF1-regulated upward-growth rate. The coupling of these two pathways facilitates the synchronized progression of etioplast maturation and hypocotyl growth, which, in turn, ultimately enables seedlings to maintain the amount of protochlorophyllide required for rapid acquisition of photoautotrophic capacity without suffering from photooxidative damage during the dark-to-light transition. Our findings illustrate the existence of a genetic signaling pathway driving soil-induced plant morphogenesis and define the specific role of ethylene in orchestrating organ-specific soil responses in Arabidopsis seedlings. PMID:24599595

  20. On the biomechanics of seedling anchorage

    NASA Astrophysics Data System (ADS)

    Crouzy, Benot; Edmaier, Katharina; Perona, Paolo

    2014-05-01

    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. Wthrich, 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).

  1. Seedling emergence on Sonoran desert dunes

    USGS Publications Warehouse

    Bowers, Janice E.

    1996-01-01

    Seedling emergence of psammophiles (plants restricted to active dunes) was examined with germination experiments and with field observations at the Algodones Dunes, California, U.S.A., and the Sierra del Rosario Dunes, Sonora, Mexico. In the field, perennial psammophiles germinated in response to smaller rainfall triggers (??? 10mm) than other woody desert plants (??? 16mm). In germination experiments, seedlings of three perennial psammophiles, Astragalus magdalenae var. peirsonii, Helianthus niveus subsp. tephrodes, and Palafoxia arida var. gigantea, emerged in larger numbers from greater soil depths than those of three nonpsammophiles, Cercidium microphyllum, Fouquieria splendens, and Palafoxia arida var. arida. Seed size for these six species did not correlate in any consistent fashion with emergence depth, suggesting that food reserves are not the only variable that ensures emergence of deeply buried psammophile seeds.

  2. TEMPORAL ALLOCATION OF 14C TO EXTRAMATRICAL HYPHAE OF ECTOMYCORRHIZAL PONDEROSA PINE SEEDLINGS

    EPA Science Inventory

    Ponderosa pine seedlings were inoculated with Hebeloma crustuliniforme either in growth pouches before they were transplanted to root-mycocosms (P seedlings), or at the time of transfer to root-mycocosms (V seedlings). ninoculated seedlings served as controls (U seedlings). he us...

  3. Volatiles from steam-distilled leaves of some plant species from Madagascar and New Zealand and evaluation of their biological activity.

    PubMed

    Costa, Rosaria; Pizzimenti, Francesco; Marotta, Francesca; Dugo, P; Santi, Luca; Mondello, Luigi

    2010-11-01

    Steam-distilled aerial parts of Ravensara aromatica and Cinnamomum camphora from Madagascar and Leptospermum scoparium from New Zealand have been subjected to qualitative and quantitative analysis by means of GC techniques. This allowed the elucidation of conflicting data present in the available literature for these species. Also, the biological activity in vitro was evaluated by measuring MICs and GIZs. PMID:21213986

  4. Kinetics for phototropic curvature by etiolated seedlings of Arabidopsis thaliana

    NASA Technical Reports Server (NTRS)

    Orbovic, V.; Poff, K. L.

    1991-01-01

    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.

  5. Safety and Tolerability of Essential Oil from Cinnamomum zeylanicum Blume Leaves with Action on Oral Candidosis and Its Effect on the Physical Properties of the Acrylic Resin

    PubMed Central

    Oliveira, Julyana de Araújo; da Silva, Ingrid Carla Guedes; Trindade, Leonardo Antunes; Lima, Edeltrudes Oliveira; Carlo, Hugo Lemes; Cavalcanti, Alessandro Leite; de Castro, Ricardo Dias

    2014-01-01

    The anti-Candida activity of essential oil from Cinnamomum zeylanicum Blume, as well as its effect on the roughness and hardness of the acrylic resin used in dental prostheses, was assessed. The safety and tolerability of the test product were assessed through a phase I clinical trial involving users of removable dentures. Minimum inhibitory concentration (MIC) and minimum fungicidal concentrations (MFC) were determined against twelve Candida strains. Acrylic resin specimens were exposed to artificial saliva (GI), C. zeylanicum (GII), and nystatin (GIII) for 15 days. Data were submitted to ANOVA and Tukey posttest (α = 5%). For the phase I clinical trial, 15 healthy patients used solution of C. zeylanicum at MIC (15 days, 3 times a day) and were submitted to clinical and mycological examinations. C. zeylanicum showed anti-Candida activity, with MIC = 625.0 µg/mL being equivalent to MFC. Nystatin caused greater increase in roughness and decreased the hardness of the material (P < 0.0001), with no significant differences between GI and GII. As regards the clinical trial, no adverse clinical signs were observed after intervention. The substance tested had a satisfactory level of safety and tolerability, supporting new advances involving the clinical use of essential oil from C. zeylanicum. PMID:25574178

  6. The standardized BHH10 extract, a combination of Astragalus membranaceus, Cinnamomum cassia, and Phellodendron amurense, reverses bone mass and metabolism in a rat model of postmenopausal osteoporosis.

    PubMed

    Huh, Jeong-Eun; Kim, Soo-Jeong; Kang, Jung-Won; Nam, Dong-Woo; Choi, Do-Young; Park, Dong-Suk; Lee, Jae-Dong

    2015-01-01

    Jasin-hwan-gagambang (BHH10), a modified prescription of Jasin-hwan, contains Astragalus membranaceus, Cinnamomum cassia, and Phellodendron amurense, and it has been traditionally used to treat osteoporosis and other inflammatory diseases. In this study, we systematically investigated the protective effects of BHH10 in ovariectomy (OVX)-induced rats. Sprague-Dawley rats were randomly divided into sham and OVX subgroups. The rats in the OVX group were treated with vehicle, BHH10, alendronate (ALN), and 17?-estradiol (E2). BHH10 treatment significantly inhibited OVX-induced increases in body weight and uterus atrophy. In addition, it significantly increased the bone mineral density (BMD) and prevented a decrease in trabecular bone volume, connectivity density, trabecular number, thickness, and separation at the total femur and femur neck. The OVX rats showed significant decreases in the serum levels of calcium and phosphorous and significant increases in the serum levels of cholesterol, low-density lipoprotein cholesterol, alkaline phosphatase, osteocalcin, C-telopeptide type 1 collagen, and bone morphogenetic protein-2. These changes were significantly reduced to near sham levels by administration of BHH10 to OVX rats. BHH10-treated rats had a greater bone mass, a better structural architecture of the bone, and higher levels of biochemical markers of the bone than did the ALN-treated or E2-treated rats. These results suggest that BHH10 reverses osteoporosis in OVX rats by stimulating bone formation or regulating bone resorption and is not associated with toxicity. PMID:25230217

  7. Hydrogen potassium adenosine triphosphatase activity inhibition and downregulation of its expression by bioactive fraction DLBS2411 from Cinnamomum burmannii in gastric parietal cells

    PubMed Central

    Tjandrawinata, Raymond R; Nailufar, Florensia; Arifin, Poppy F

    2013-01-01

    This study assessed the gastric acid antisecretory effect of DLBS2411 fractionated from Cinnamomum burmannii. Hydrogen potassium adenosine triphosphatase (H+/K+ ATPase) activity and its gene expression were observed, and the antioxidant activity of DLBS2411 was also investigated. Treatment of DLBS2411 decreased the level of H+/K+ ATPase messenger RNA expression on human embryonic kidney 293 cells and rat gastric parietal cells in a dose-dependent manner, in vitro and ex vivo. DLBS2411 also acted as a competitive inhibitor by showing inhibition in gastric H+/K+ ATPase activity at various pHs. In gastric ulcer animal models induced with indomethacin and ethanol, DLBS2411showed a reduction in the number of petechiae, suggesting that the fraction also confers gastroprotective activity. Moreover, DLBS2411 was also found to have potent antioxidant activity. Taken together, DLBS2411 is a promising novel agent for the management of dyspepsia, a condition of hyperacidity and diseases in the stomach requiring gastroprotection. PMID:24101879

  8. Safety profile assessment and efficacy of chemically characterized Cinnamomum glaucescens essential oil against storage fungi, insect, aflatoxin secretion and as antioxidant.

    PubMed

    Prakash, Bhanu; Singh, Priyanka; Yadav, Shilpee; Singh, S C; Dubey, N K

    2013-03-01

    The study explores the efficacy of Cinnamomum glaucescens essential oil (EO) as insecticidal, antifungal, antiaflatoxin and antioxidant agent so as to recommend its application as plant based preservatives for food commodities. The study reports the chemical characterization of C. glaucescens oil and its 100% insecticidal activity against insect pest Callosobruchus chinensis on 12 h exposure and 98.74% oviposition deterrency at 0.15 ?l/ml. The EO significantly inhibited growth and aflatoxin production by toxigenic strain of Aspergillus flavus LHP-10 at 4.5 and 3.5 ?l/ml respectively. EO also showed appreciable antioxidant activity (IC(50) value=15.1 ?l/ml), non phytotoxic nature on chickpea seed germination and in vivo potential as fumigant in food system providing 71.07% protection of chickpea samples from fungal contamination and 100% antifeedant activity against the insect invasion. The EO exhibited non-mammalian toxicity showing high LD(50) (3971.34 ?l/kg) during oral toxicity on mice. PMID:23220615

  9. Effect of essential oils of Syzygium aromaticum and Cinnamomum zeylanicum and their major components on biofilm production in Staphylococcus aureus strains isolated from milk of cows with mastitis.

    PubMed

    Budri, P E; Silva, N C C; Bonsaglia, E C R; Fernandes Júnior, A; Araújo Júnior, J P; Doyama, J T; Gonçalves, J L; Santos, M V; Fitzgerald-Hughes, D; Rall, V L M

    2015-09-01

    Bovine mastitis is an inflammation of the mammary glands of cows and causes significant economic losses in dairy cattle. Staphylococcus aureus is one of the microorganisms most commonly isolated. Novel agents are required in agricultural industries to prevent the development of mastitis. The production of biofilm by Staph. aureus facilitates the adhesion of bacteria to solid surfaces and contributes to the transmission and maintenance of these bacteria. The effect of the essential oils of Syzygium aromaticum (clove; EOSA) and Cinnamomum zeylanicum (cinnamon; EOCZ) and their major components, eugenol and cinnamaldehyde, on Staph. aureus biofilm formation on different surfaces was investigated. The results showed a significant inhibition of biofilm production by EOSA on polystyrene and stainless steel surfaces (69.4 and 63.6%, respectively). However, its major component, eugenol, was less effective on polystyrene and stainless steel (52.8 and 19.6%, respectively). Both EOCZ and its major component, cinnamaldehyde, significantly reduced biofilm formation on polystyrene (74.7 and 69.6%, respectively) and on stainless steel surfaces (45.3 and 44.9%, respectively). These findings suggest that EOSA, EOCZ, and cinnamaldehyde may be considered for applications such as sanitization in the food industry. PMID:26142866

  10. Antibacterial Mode of Action of Cinnamomum verum Bark Essential Oil, Alone and in Combination with Piperacillin, Against a Multi-Drug-Resistant Escherichia coli Strain.

    PubMed

    Yap, Polly Soo Xi; Krishnan, Thiba; Chan, Kok-Gan; Lim, Swee Hua Erin

    2015-08-01

    This study aimed to investigate the mechanism of action of the cinnamon bark essential oil (CB), when used singly and also in combination with piperacillin, for its antimicrobial and synergistic activity against beta-lactamase TEM-1 plasmid-conferred Escherichia coli J53 R1. Viable count of this combination showed a complete killing profile at 20 h and further confirmed its synergistic effect by reducing the bacteria cell numbers. Analysis on the stability of treated cultures for cell membrane permeability by CB when tested against sodium dodecyl sulfate revealed that the bacterial cell membrane was disrupted by the essential oils. Scanning electron microscopy observation and bacterial surface charge measurement also revealed that CB causes irreversible membrane damage and reduces the bacterial surface charge. In addition, bioluminescence expression of Escherichia coli [pSB1075] and E. coli [pSB401] by CB showed reduction, indicating the possibility of the presence of quorum sensing (QS) inhibitors. Gas-chromatography and mass spectrometry of the essential oil of Cinnamomum verum showed that trans-cinnamaldehyde (72.81%), benzyl alcohol (12.5%), and eugenol (6.57%) were the major components in the essential oil. From this study, CB has the potential to reverse E. coli J53 R1 resistance to piperacillin through two pathways; modification in the permeability of the outer membrane or bacterial QS inhibition. PMID:25381741

  11. Sod cutting and soil biota effects on seedling performance

    NASA Astrophysics Data System (ADS)

    Weijtmans, Kim; Jongejans, Eelke; van Ruijven, Jasper

    2009-09-01

    Sod cutting (i.e. top soil removal) is a restoration management option for enhancing seedling establishment and for lowering the nutrient concentration in eutrophicated soils of nutrient-poor species-rich grasslands. Removal of the upper soil changes not only abiotic soil properties but may also affect the resident soil community. We investigated the effects of sod cutting on the establishment and performance of two endangered plant species ( Cirsium dissectum and Succisa pratensis) while simultaneously manipulating the interaction between seedlings and soil biota. In intact grassland and sod-cut areas at two localities, seedlings were grown in plastic tubes. Half of the tubes had a filter that excluded roots but allowed entry of fungal hyphae and soil microorganisms. The other tubes were closed (i.e. no contact with the surrounding soil). In a greenhouse experiment we studied the effect of soil solutions (with or without fungal tissue) from three grasslands and three sod-cut areas on seedling growth. Sod cutting had a positive net effect on seedling growth for S. pratensis. Access to (mycorrhizal) fungi and other soil biota resulted in a negative impact on seedling growth of both plant species, both in grassland and sod-cut areas. The greenhouse experiment confirmed that the soil biota in these meadows reduced seedling growth. Although sod cutting did not mitigate negative plant-soil feedback, it enhanced seedling growth, presumably by decreasing competition for light. Sod cutting is therefore very useful when seedling establishment needs to be stimulated.

  12. Seedlings Finally Get Their Due: Book Review of Seedling Ecology and Evolution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Book Review of: Seedling Ecology and Evolution. Ed. Leck, Mary Allessio, Parker, V. Thomas and Simpson, Robert L. Cambridge University Press, Cambridge, UK. 2008. Many plant demographers find themselves, at some point, staring at a dataset full of detailed information on juvenile and adult plants,...

  13. Habitat-related variation in seedling recruitment of Gentiana pannonica

    NASA Astrophysics Data System (ADS)

    Ekrtová, Ester; Košnar, Jan

    2012-11-01

    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.

  14. Examining salt stress for improvement of seedling vigor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Emergence and stand establishment through the first 10 weeks after planting continue to be primary concerns of sugar beet growers worldwide. Our goal is to understand the genes and genetics of seedling vigor, with vigor defined here as the ability of seedlings to tolerate adverse environments. Ongoi...

  15. Chilling stress response of post-emergent cotton seedlings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    • Early season development of cotton is often impaired by sudden episodes of chilling temperature. We determined the chilling response specific to post-emergent 13-d-old cotton seedlings. • Seedlings were gradually chilled during the dark period and rewarmed during the night-to-day transition. Fo...

  16. Evaluation of Promalin to promote growth of young mangosteen seedlings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A major impediment to the development of a mangosteen (Garcinia mangostana L.) industry is the long pre-bearing stage that seedlings take to produce fruits. A field study was conducted to determine the effect of Promalin on the growth of mangosteen seedlings. Promalin was applied as a foliar spray...

  17. Sand abrasion injury and biomass partitioning in cotton seedlings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind blown soil particle abrasion negatively impacts millions of hectares of crops annually. The goal of this study was to examine the effects of wind and wind blown sand abrasion damage on cotton (Gossypium hirsutum L.) seedling biomass partitioning to leaves, stems, and roots. Seedlings of three ...

  18. Seedling emergence of yellow woodsorrel in eastern South Dakota

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yellow woodsorrel is a perennial weed invading no-till rotations in eastern South Dakota. This study quantified the seedling emergence pattern of yellow woodsorrel across a four-year period. Yellow woodsorrel began emerging in early May and continued for 14 weeks. Approximately 80% of seedlings em...

  19. Coumarin pretreatment alleviates salinity stress in wheat seedlings.

    PubMed

    Saleh, Ahmed Mahmoud; Madany, M M Y

    2015-03-01

    The potentiality of COU to improve plant tolerance to salinity was investigated. Wheat grains were primed with COU (50 ppm) and then grown under different levels of NaCl (50, 100, 150 mM) for two weeks. COU pretreatment improved the growth of wheat seedling under salinity, relative to COU-untreated seedlings, due to the accumulation of osmolytes such as soluble sugars and proline. Moreover, COU treatment significantly improved K(+)/Na(+) ratio in the shoots of both salt stressed and un-stressed seedlings. However, in the roots, this ratio increased only under non-salinity. In consistent with phenylalanine ammonia lyase (PAL), phenolics and flavonoids were accumulated in COU-pretreated seedlings under the higher doses of salinity, relative to COU-untreated seedlings. COU primed seedlings showed higher content of the coumarin derivative, scopoletin, and salicylic, chlorogenic, syringic, vanillic, gallic and ferulic acids, under both salinity and non-salinity conditions. Salinity stress significantly improved the activity of peroxidase (POD) in COU-pretreated seedlings. However, the effect of COU on the total antioxidant capacity (TAC) was only obtained at the highest dose of NaCl (150 mM). The present results suggest that COU pretreatment could alleviate the adverse effect of salinity on the growth of wheat seedlings through enhancing, at least partly, the osmoregulation process and antioxidant defense system. PMID:25634803

  20. SEEDBED SURFACE GEOMETRY EFFECTS ON SOIL CRUSTING AND SEEDLING EMERGENCE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seedling emergence is the crucial first step in crop establishment; however, crops frequently must penetrate or lift a thin, dense, soil crust formed during rainstorms. Shaping the soil surface into a small ridge or cap above the seed may promote crust fractures and improve seedling emergence and vi...

  1. A hydrothermal seedling emergence model for giant ragweed (Ambrosia trifida)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Late-season seedling emergence of giant ragweed in Ohio crop fields complicates efforts for predicting the optimum time to implement control measures for minimizing crop-yield losses. Our objectives were to develop a hydrothermal seedling emergence model for a late-emerging biotype in Ohio and valid...

  2. Sand abrasion injury and biomass partitioning in cotton seedlings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Millions of acres of crops are exposed to wind blown sand abrasion injury each year and in many instances the damage is thought to be sufficiently severe to require replanting. The goal of this study was to determine the effects of wind blown sand abrasion duration on cotton seedlings. Seedlings of ...

  3. Enantioselective Phytotoxicity of Imazamox Against Maize Seedlings.

    PubMed

    Wei, Jing; Zhang, Xiaoxiao; Li, Xuesheng; Zeng, Dongqiang; Tan, Huihua

    2016-02-01

    There is increasing concern about the enantioselective effects of chiral herbicides. To study the enantioselective toxicity of the chiral herbicide imazamox on maize, maize seedlings (Zhengda 619, Zea mays L.) were exposed to imazamox racemate and enantiomers in hydroponic experiments. The results showed that imazamox enantiomers selectively affected maize. The effective concentration of Rac-, S- and R-imazamox that caused 50 % inhibition after 5 days treatments (EC50,5d) were 0.4212, 1.2142 and 0.2460 mg L(-1), respectively, for maize root length; 0.0002, 0.1005, 0.0032 mg L(-1), respectively, for maize root fresh weight; 0.7114, 1.4056 and 0.4530 mg L(-1), respectively, for maize shoot height; 0.6220, 1.5418, 0.2286 mg L(-1), respectively, for maize shoot fresh weight; and 0.1100, 0.3306, 0.0307 mg L(-1), respectively, for the total chlorophyll content of leaves. The root morphological parameters and root activity reflected the toxicity effects in the order R-imazamox > Rac-imazamox > S-imazamox. Maize roots were more sensitive to imazamox than maize shoots. The chiral herbicide imazamox poses enantioselective phytotoxicity on maize seedlings: the order of toxicity is R-imazamox > Rac-imazamox > S-imazamox. PMID:26508428

  4. Importation of aquaculture seedlings to Japan.

    PubMed

    Wakabayashi, H

    1996-06-01

    Japan is one of the largest consumers of fishery products in the world. Importation of various fishery commodities - including larvae and eggs for aquaculture - is increasing due to high consumer demand. Elvers of Anguilla anguilla have been imported from Europe since the late 1960s. Eyed eggs of coho salmon (Oncorhynchus kisutch) are imported from North America. During the last decade, over-production caused the price of Japanese amberjack (or 'yellowtail') (Seriola quinqueradiata) and Japanese seabream (Pagrus major) to drop, forcing farmers to venture into the culture of other species. A variety of marine fish seedlings are now imported from Asian countries. Almost all aquaculture production of coho salmon, greater amberjack (Seriola dumerili), seabass (Lateolabrax japonicus), rockfish (Sebastes spp.) and groupers (Epinephlus septemfaciatus, etc.) depends on imported seedlings. These species accounted for approximately 9% by value of marine finfish production in Japan in 1993. Apart from ubiquitous or endemic pathogens, a considerable number of exotic microorganisms and parasites are suspected to have accompanied fish eggs and larvae imported for aquaculture purposes. On a voluntary basis, 80-90% of imported salmon eggs are being examined for bacterial kidney disease and salmon viruses by semi-governmental organisation. Voluntary inspections are also being conducted on some other fish species imported from foreign countries. No legislation exists, however, for the control of exotic fish pathogens. PMID:8890372

  5. Process-based modeling of temperature and water profiles in the seedling recruitment zone: Part II. Seedling emergence timing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Predictions of seedling emergence timing for spring wheat are facilitated by process-based modeling of the microsite environment in the shallow seedling recruitment zone. Hourly temperature and water profiles within the recruitment zone for 60 days after planting were simulated from the process-base...

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

    PubMed Central

    2012-01-01

    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 chromatographymass 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. PMID:22882757

  7. The Standardized BHH10 Extract, a Combination of Astragalus membranaceus, Cinnamomum cassia, and Phellodendron amurense, Reverses Bone Mass and Metabolism in a Rat Model of Postmenopausal Osteoporosis

    PubMed Central

    Huh, Jeong-Eun; Kim, Soo-Jeong; Kang, Jung-Won; Nam, Dong-Woo; Choi, Do-Young; Park, Dong-Suk; Lee, Jae-Dong

    2015-01-01

    Jasin-hwan-gagambang (BHH10), a modified prescription of Jasin-hwan, contains Astragalus membranaceus, Cinnamomum cassia, and Phellodendron amurense, and it has been traditionally used to treat osteoporosis and other inflammatory diseases. In this study, we systematically investigated the protective effects of BHH10 in ovariectomy (OVX)-induced rats. SpragueDawley rats were randomly divided into sham and OVX subgroups. The rats in the OVX group were treated with vehicle, BHH10, alendronate (ALN), and 17?-estradiol (E2). BHH10 treatment significantly inhibited OVX-induced increases in body weight and uterus atrophy. In addition, it significantly increased the bone mineral density (BMD) and prevented a decrease in trabecular bone volume, connectivity density, trabecular number, thickness, and separation at the total femur and femur neck. The OVX rats showed significant decreases in the serum levels of calcium and phosphorous and significant increases in the serum levels of cholesterol, low-density lipoprotein cholesterol, alkaline phosphatase, osteocalcin, C-telopeptide type 1 collagen, and bone morphogenetic protein-2. These changes were significantly reduced to near sham levels by administration of BHH10 to OVX rats. BHH10-treated rats had a greater bone mass, a better structural architecture of the bone, and higher levels of biochemical markers of the bone than did the ALN-treated or E2-treated rats. These results suggest that BHH10 reverses osteoporosis in OVX rats by stimulating bone formation or regulating bone resorption and is not associated with toxicity. 2014 The Authors. Phytotherapy Research published by John Wiley & Sons Ltd. PMID:25230217

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

    USGS Publications Warehouse

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

    2005-01-01

    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.

  9. Flow and scour constraints on uprooting of pioneer woody seedlings

    NASA Astrophysics Data System (ADS)

    Bywater-Reyes, Sharon; Wilcox, Andrew C.; Stella, John C.; Lightbody, Anne F.

    2015-11-01

    Scour and uprooting during flood events is a major disturbance agent that affects plant mortality rates and subsequent vegetation composition and density, setting the trajectory of physical-biological interactions in rivers. During flood events, riparian plants may be uprooted if they are subjected to hydraulic drag forces greater than their resisting force. We measured the resisting force of woody seedlings established on river bars with in situ lateral pull tests that simulated flood flows with and without substrate scour. We quantified the influence of seedling size, species (Populus and Tamarix), water-table depth, and scour depth on resisting force. Seedling size and resisting force were positively related with scour depth and water-table depth—a proxy for root length—exerting strong and opposing controls on resisting force. Populus required less force to uproot than Tamarix, but displayed a greater increase in uprooting force with seedling size. Further, we found that calculated mean velocities required to uproot seedlings were greater than modeled flood velocities under most conditions. Only when plants were either shallowly rooted or subjected to substrate scour (≥0.3 m) did the calculated velocities required for uprooting decrease to within the range of modeled flood velocities, indicating that drag forces alone are unlikely to uproot seedlings in the absence of extreme events or bar-scale sediment transport. Seedlings on river bars are most resilient to uprooting when they are large, deeply rooted, and unlikely to experience substrate scour, which has implications for ecogeomorphic evolution and river management.

  10. BIM LAU-PE: Seedlings in Microgravity

    NASA Astrophysics Data System (ADS)

    Gass, S.; Pennese, R.; Chapuis, D.; Dainesi, P.; Nebuloni, S.; Garcia, M.; Oriol, A.

    2015-09-01

    The effect of gravity on plant roots is an intensive subject of research. Sounding rockets represent a costeffective platform to study this effect under microgravity conditions. As part of the upcoming MASER 13 sounding rocket campaign, two experiments on Arabidopsis thaliana seedlings have been devised: GRAMAT and SPARC. These experiments are aimed at studying (1) the genes that are specifically switched on or off during microgravity, and (2) the position of auxin-transporting proteins during microgravity. To perform these experiments, RUAG Space Switzerland site of Nyon, in collaboration with the Swedish Space Corporation (SSC) and the University of Freiburg, has developed the BIM LAU-PE (Biolology In Microgravity Late Access Unit Plant Experiment). In the following an overview of the BIM LAU-PE design is presented, highlighting specific module design features and verifications performed. A particular emphasis is placed on the parabolic flight experiments, including results of the micro-g injection system validation.

  11. Arthropod invasion disrupts Cycas micronesica seedling recruitment

    PubMed Central

    Terry, L. Irene

    2011-01-01

    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

  12. Arborescent palm seed morphology and seedling distribution.

    PubMed

    Salm, Rodolfo

    2005-11-01

    This study examines how the seed morphology of two large arborescent palms, Attalea maripa (Aubl.) Mart. and Astrocaryum aculeatum G. Mey, may affect their seed shadow in a seasonally dry Amazonian forest. In addition to being smaller and produced in larger numbers than those of A. aculeatum, A. maripa seeds also presented a substantially lower amount of nutritional reserves available for the embryo. However, A. maripa seedlings were found in much higher numbers than those of A. aculeatum. The results suggest that, within the spatial scale considered, the seed rain of A. maripa is more restricted to the area surrounding around reproductive conspecifics than that of A. aculeatum. Furthermore, in comparison with those of A. aculeatum, the smaller seeds of A. maripa might be less attractive to scatterhoarding rodents (e.g. Dasyprocta aguti). The pattern observed emphasizes the importance of scatterhoarding rodents as dispersers of large-seeded plant species in Neotropical forests. PMID:16532195

  13. Growth of ponderosa pine seedlings as affected by air pollution

    NASA Astrophysics Data System (ADS)

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

    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.

  14. Photomodulation of strigolactone biosynthesis and accumulation during sunflower seedling growth.

    PubMed

    Bharti, Niharika; Tripathi, Smita; Bhatla, Satish Chander

    2015-01-01

    Present investigations report the presence of strigolactones (SLs) and photomodulation of their biosynthesis in sunflower seedlings (roots, cotyledons and first pair of leaves) during early phase of seedling development. Qualitative analyses and characterization by HPLC, ESI-MS and FT-IR revealed the presence of more than one type of SLs. Orobanchyl acetate was detected both in roots and leaves. Five-deoxystrigol, sorgolactone and orobanchol were exclusively detected in seedling roots. Sorgomol was detectable only in leaves. HPLC eluted fraction from seedling roots and leaves co-chromatographing with GR24 (a synthetic SL) could also bring about germination in Orobanche cernua (a weed) seeds, which are established to exhibit SL - mediated germination, thereby indicating the SL identity of the eluates using this bioassay. SLs accumulation was always more in the roots of light-grown seedlings, it being maximum at 4 d stage. Although significant activity of carotenoid cleavage dioxygenase (CCD, the enzyme critical for SL biosynthesis) was detected in 2 d old seedling roots, SLs remained undetectable in cotyledons at all stages of development and also in the roots of 2 d old light and dark-grown seedlings. Roots of light-grown seedlings showed maximum CCD activity during early (2 d) stage of development, thereby confirming photomodulation of enzyme activity. These observations indicate the migration of a probable light-sensitized signaling molecule (yet to be identified) or a SL precursor from light exposed aerial parts to the seedling roots maintained in dark. Thus, a photomodulation and migration of SL precursor/s is evident from the present work. PMID:26252191

  15. Photomodulation of strigolactone biosynthesis and accumulation during sunflower seedling growth

    PubMed Central

    Bharti, Niharika; Tripathi, Smita; Bhatla, Satish Chander

    2015-01-01

    Present investigations report the presence of strigolactones (SLs) and photomodulation of their biosynthesis in sunflower seedlings (roots, cotyledons and first pair of leaves) during early phase of seedling development. Qualitative analyses and characterization by HPLC, ESI-MS and FT-IR revealed the presence of more than one type of SLs. Orobanchyl acetate was detected both in roots and leaves. Five-deoxystrigol, sorgolactone and orobanchol were exclusively detected in seedling roots. Sorgomol was detectable only in leaves. HPLC eluted fraction from seedling roots and leaves co-chromatographing with GR24 (a synthetic SL) could also bring about germination in Orobanche cernua (a weed) seeds, which are established to exhibit SL – mediated germination, thereby indicating the SL identity of the eluates using this bioassay. SLs accumulation was always more in the roots of light-grown seedlings, it being maximum at 4 d stage. Although significant activity of carotenoid cleavage dioxygenase (CCD, the enzyme critical for SL biosynthesis) was detected in 2 d old seedling roots, SLs remained undetectable in cotyledons at all stages of development and also in the roots of 2 d old light and dark-grown seedlings. Roots of light-grown seedlings showed maximum CCD activity during early (2 d) stage of development, thereby confirming photomodulation of enzyme activity. These observations indicate the migration of a probable light-sensitized signaling molecule (yet to be identified) or a SL precursor from light exposed aerial parts to the seedling roots maintained in dark. Thus, a photomodulation and migration of SL precursor/s is evident from the present work. PMID:26252191

  16. DIVERGENT SELECTION FOR SEEDLING TILLER NUMBER IN BIG BLUESTEM AND SWITCHGRASS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grass seedling tiller number and shoot weight are traits associated with seedling vigor. The response to selection for high shoot weight and divergent selection for seedling tiller number in big bluestem (Andropogon gerardii Vitman) and switchgrass (Panicum virgatum L.) seedlings and realized herit...

  17. Substrate influences ecophysiological performance of tree seedlings.

    PubMed

    Pröll, Gisela; Hietz, Peter; Delaney, Christina M; Katzensteiner, Klaus

    2016-01-01

    Unfavourable soil conditions frequently limit tree regeneration in mountain forests on calcareous bedrock. Rocky, shallow organic soils on dolomite pose a particular problem for tree regeneration due to commonly restricted water and nutrient supplies. Moreover, an often dense layer of understorey vegetation competes for the limited resources available. Hence, an array of interacting factors impairs tree seedlings' performance on dolomite, but there is little information on the ecophysiological mechanisms. We studied the effects of substrate, competing vegetation and foliar nutrient concentrations on the photosynthetic rate (A), stomatal conductance (gs) and leaf water potentials (ψ) of sycamore (Acer pseudoplatanus L.), beech (Fagus sylvatica L.), spruce [Picea abies (L.) Karst.] and larch (Larix decidua Mill.) under controlled (well-watered/drought-stressed) conditions and under prevailing field conditions. While A and gs of well-watered spruce in the pot experiment were reduced by the mineral substrate, the organic dolomite substrate with dense competing vegetation reduced gs and ψ of sycamore, spruce and larch under drought-stressed conditions in the field. For sycamore and spruce, A and gs were strongly correlated with foliar nitrogen (N) and potassium (K) concentrations in the pot experiment. In contrast, soil water primarily affected beech and larch. Finally, dense competing vegetation negatively affected A and gs of spruce and A of larch on dolomite. Our results highlight the critical role of N, K and water availability for tree seedlings in shallow soils on calcareous bedrock. On these sites, natural tree regeneration is at particular risk from episodic drought, a likely consequence of climate change. PMID:26446268

  18. Identification of chromosome regions associated with seedling vigor in rice.

    PubMed

    Huang, Zheng; Yu, Ting; Su, Li; Yu, Si-Bin; Zhang, Zhi-Hong; Zhu, Ying-Guo

    2004-06-01

    Seedling vigor is important for optimum stand establishment in rice cropping. In this paper,a set of 264 F12 recombinant inbred lines (RILs) derived by single seed descent from a cross between Lemont (japonica) and Teqing (indica) was phenotyped for three seedling vigor related traits, including seed germination rate (GR), seedling shoot length and dry weight by the rolled paper towel tests. The phenotype data and a linkage map consisting of 198 DNA markers were combined to map quantitative trait loci (QTL) for seedling vigor by using a computer program QTLMapper1.0. A total of 13 putative main-effect QTL were detected. All of these QTL had much smaller effects on the traits with a mean R2 of 6.2%, ranging from 2.9% to 12.7%. As for digenic interaction, 18 pairs of epistatic loci with R2 > or = 5% were resolved with a mean R2 of 6.9% ,ranging from 5.1% to 11.8%, which was slightly larger than that of the main-effect QTL identified for the traits. The majority of the main-effect and epistatic loci detected for seedling vigor related traits were clustered in a few chromosome regions. Together, seven such chromosome regions (CRs), each with three or more seedling vigor main-effect and epistatic loci, were found to be highly associated with seedling vigor. These CRs can be classified into three types, i.e. M-CRs, E-CRs and ME-CRs. For some CRs just like CR(SV-6), the QTL within one CR were found to interact simultaneously with QTL within more than one other CRs to affect different seedling vigor related traits. The above results revealed that seedling vigor in rice is controlled by many loci, most of which have relatively small effects. Comparatively, epistasis as a genetic factor would be more important than main-effects of QTL for seedling vigor in rice. Nevertheless, the effects of the QTL are still large enough to be detected and in fact several chromosome regions were found to be highly associated with seedling vigor in very different populations as compared with previous studies. Molecular tagging of favorable alleles and marker-aided selection strategy may, therefore, be a promising approach to the improvement of rice seedling vigor. PMID:15490878

  19. ARC EMCS Experiments (Seedling Growth-2) Experiment Status

    NASA Technical Reports Server (NTRS)

    Heathcote, David; Steele, Marianne

    2015-01-01

    Presentation of the status of the ARC ISS (International Space Station) Experiment, Seedling Growth-2 to the Payload Operations Investigator Working Group meeting at MSFC, Huntsville AL. The experiment employs the European Modular Cultivation System (ECMS).

  20. Space Station Live: Seedling Growth - Duration: 5 minutes, 54 seconds.

    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...

  1. Limitations to seedling establishment in a mesic Hawaiian forest.

    PubMed

    Denslow, Julie S; Uowolo, Amanda L; Hughes, R Flint

    2006-05-01

    While invasive species may be visible indicators of plant community degradation, they may not constitute the only, or even the primary, limitation to stand regeneration. We used seed-augmentation and grass-removal experiments under different canopy conditions to assess the relative importance of dispersal limitation, resource availability, and competition on seedling establishment in the understory shrubs Sophora chrysophilla, Dodonea viscosa, and Pipturus albidus in a montane mesic forest in Hawaii. The study location was an Acacia koa-Metrosideros polymorpha forest at 1000-1500 m elevation on the leeward side of Hawaii Island; it is a closed-canopy forest historically subject to logging and grazing by cattle and sheep and currently dominated by the exotic grass, Ehrharta stipoides, in the herb layer. Seedling establishment after 1 and 2 years was strongly dispersal limited in Sophora and Dodonea, but not in Acacia, a non-augmented species in which abundant seedlings established, nor in Pipterus, in which only one seedling established in 2 years. Grass cover reduced seedling establishment in Acacia, Sophora, and Dodonea and, for the latter two species, seedling establishment was substantially greater in the warmer, more moist forest at the lowest elevation. Light, moisture, and resin-captured N and P were more strongly affected by elevation and canopy composition than by grass cover, but in most cases seedling establishment was not positively correlated with resource availability. Limitations to the establishment of woody seedlings in this forest-grassland mixture vary among species; however, both dispersal limitation and competition from a shade-tolerant grass are important deterrents to regeneration in these forests. PMID:16450179

  2. Eucalyptus obliqua seedling growth in organic vs. mineral soil horizons.

    PubMed

    Barry, Karen M; Janos, David P; Nichols, Scott; Bowman, David M J S

    2015-01-01

    Eucalyptus obliqua, the most widespread timber tree in Tasmania, is a pioneer after fire which can eliminate the organic layer of forest soil, exposing the underlying mineral soil. We compared seedling growth, mycorrhiza formation, and mineral nutrient limitation in organic layer vs. mineral soil. We grew E. obliqua seedlings separately in pots of organic layer and mineral soil in a glasshouse. Additional treatments of organic soil only, involved fully crossed methyl-bromide fumigation and fertilization. Fertilization comprised chelated iron for 121 days after transplant (DAT) followed by soluble phosphorus. At 357 DAT, whole plant dry weight was three times greater in ambient organic than in mineral soil. In organic soil, fumigation halved ectomycorrhiza abundance and reduced seedling growth at 149 DAT, but by 357 DAT when negative effects of fumigation on seedling growth had disappeared, neither fumigation nor fertilization affected mycorrhiza abundance. Iron fertilization diminished seedling growth, but subsequent phosphorus fertilization improved it. E. obliqua seedlings grow much better in organic layer soil than in mineral soil, although phosphorus remains limiting. The prevalent forestry practice of burning to mineral soil after timber harvest exposes a poor growth medium likely only partially compensated by fire-induced mineral soil alterations. PMID:25750650

  3. Eucalyptus obliqua seedling growth in organic vs. mineral soil horizons

    PubMed Central

    Barry, Karen M.; Janos, David P.; Nichols, Scott; Bowman, David M. J. S.

    2015-01-01

    Eucalyptus obliqua, the most widespread timber tree in Tasmania, is a pioneer after fire which can eliminate the organic layer of forest soil, exposing the underlying mineral soil. We compared seedling growth, mycorrhiza formation, and mineral nutrient limitation in organic layer vs. mineral soil. We grew E. obliqua seedlings separately in pots of organic layer and mineral soil in a glasshouse. Additional treatments of organic soil only, involved fully crossed methyl-bromide fumigation and fertilization. Fertilization comprised chelated iron for 121 days after transplant (DAT) followed by soluble phosphorus. At 357 DAT, whole plant dry weight was three times greater in ambient organic than in mineral soil. In organic soil, fumigation halved ectomycorrhiza abundance and reduced seedling growth at 149 DAT, but by 357 DAT when negative effects of fumigation on seedling growth had disappeared, neither fumigation nor fertilization affected mycorrhiza abundance. Iron fertilization diminished seedling growth, but subsequent phosphorus fertilization improved it. E. obliqua seedlings grow much better in organic layer soil than in mineral soil, although phosphorus remains limiting. The prevalent forestry practice of burning to mineral soil after timber harvest exposes a poor growth medium likely only partially compensated by fire-induced mineral soil alterations. PMID:25750650

  4. Alcohol dehydrogenase and an inactivator from rice seedlings

    SciTech Connect

    Shimomura, S.; Beevers, H.

    1983-01-01

    Alcohol dehydrogenase (ADH) was measured in the various organs of rice seedlings (Oryza sativa) growing in air. In extracts from ungerminated seeds, the ADH is stable, but in extracts from seedlings more than 2 days old the enzyme initially present loses activity in a time- and temperature-dependent fashion, due to the presence of an inactivating component which increases with age in roots and shoots. The inactivation can be prevented completely by dithiothreitol, and when this is included in the extraction medium the apparent loss of total ADH in roots and shoots with age is not observed. In seedlings grown in N/sub 2/, ADA levels in coleoptile extracts are higher than those in air, the enzyme is stable, and no inactivator can be detected. When seedlings grown for 5 days in air were transferred to N/sub 2/ for 3 days, ADA levels increased and there was a decline in inactivator activity. Transfer back to air after 1 day in N/sub 2/ led to loss of the accumulated ADH and increase in inactivator. These reciprocal changes and the fact that the inactivator is absent from coleoptiles of seedlings grown in N/sub 2/ appear to suggest a regulator role for the inactivator in vivo. However, it is clear that high levels of inactivator and ADH can exist in cells of seedlings grown in air for long periods without loss of enzyme activity, and it is argued that they must normally be separately compartmented.

  5. Ethylene and the Growth of Rice Seedlings 1

    PubMed Central

    Satler, Sergio O.; Kende, Hans

    1985-01-01

    Etiolated whole rice seedlings enclosed in sealed vials produced ethylene at a rate of 0.9 picomole per hour per seedling. When 2-centimeter-long shoots were subdivided into 5-millimeter-long sections, the sections containing the tip of the shoot evolved 37% of the total ethylene with the remaining 63% being produced along a gradient decreasing to the base of the shoot. The tip of the coleoptile also had the highest level of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid and of the ethylene-forming enzyme activity. Ethylene is one of the factors controlling coleoptile elongation. Decapitation of the seedling reduced ethylene evolution to one-third its original level and inhibited coleoptile growth. In short-term experiments, the growth rate of decapitated seedlings was restored to almost that of intact seedlings by application of ethylene at a concentration of 10 microliters per liter. Apart from ethylene, O2 also participates in the control of coleoptile growth. When rice seedlings were grown in a gas mixture of N2 and O2, the length of the coleoptiles reached a maximum at a concentration of 2.5% O2. Lower and higher concentrations of O2 reduced coleoptile growth. The effect of exogenous ethylene on coleoptile growth was also O2 dependent. PMID:16664369

  6. The Vibration Ring. Phase 1; [Seedling Fund

    NASA Technical Reports Server (NTRS)

    Asnani, Vivake M.; Krantz, Timothy L.; Delap, Damon C.; Stringer, David B.

    2014-01-01

    The vibration ring was conceived as a driveline damping device to prevent structure-borne noise in machines. It has the appearance of a metal ring, and can be installed between any two driveline components like an ordinary mechanical spacer. Damping is achieved using a ring-shaped piezoelectric stack that is poled in the axial direction and connected to an electrical shunt circuit. Surrounding the stack is a metal structure, called the compression cage, which squeezes the stack along its poled axis when excited by radial driveline forces. The stack in turn generates electrical energy, which is either dissipated or harvested using the shunt circuit. Removing energy from the system creates a net damping effect. The vibration ring is much stiffer than traditional damping devices, which allows it to be used in a driveline without disrupting normal operation. In phase 1 of this NASA Seedling Fund project, a combination of design and analysis was used to examine the feasibility of this concept. Several designs were evaluated using solid modeling, finite element analysis, and by creating prototype hardware. Then an analytical model representing the coupled electromechanical response was formulated in closed form. The model was exercised parametrically to examine the stiffness and loss factor spectra of the vibration ring, as well as simulate its damping effect in the context of a simplified driveline model. The results of this work showed that this is a viable mechanism for driveline damping, and provided several lessons for continued development.

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

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    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.

  8. Assessing Posidonia oceanica seedling substrate preference: an experimental determination of seedling anchorage success in rocky vs. sandy substrates.

    PubMed

    Alagna, Adriana; Fernndez, Toms Vega; Anna, Giovanni D; Magliola, Carlo; Mazzola, Salvatore; Badalamenti, Fabio

    2015-01-01

    In the last decades the growing awareness of the ecological importance of seagrass meadows has prompted increasing efforts to protect existing beds and restore degraded habitats. An in-depth knowledge of factors acting as major drivers of propagule settlement and recruitment is required in order to understand patterns of seagrass colonization and recovery and to inform appropriate management and conservation strategies. In this work Posidonia oceanica seedlings were reared for five months in a land-based culture facility under simulated natural hydrodynamic conditions to identify suitable substrates for seedling anchorage. Two main substrate features were investigated: firmness (i.e., sand vs. rock) and complexity (i.e., size of interstitial spaces between rocks). Seedlings were successfully grown in culture tanks, obtaining overall seedling survival of 93%. Anchorage was strongly influenced by substrate firmness and took place only on rocks, where it was as high as 89%. Anchorage occurred through adhesion by sticky root hairs. The minimum force required to dislodge plantlets attached to rocky substrates reached 23.830 N (equivalent to 2.43 kg), which would potentially allow many plantlets to overcome winter storms in the field. The ability of rocky substrates to retain seedlings increased with their complexity. The interstitial spaces between rocks provided appropriate microsites for seedling settlement, as seeds were successfully retained, and a suitable substrate for anchorage was available. In conclusion P. oceanica juveniles showed a clear-cut preference for hard substrates over the sandy one, due to the root system adhesive properties. In particular, firm and complex substrates allowed for propagule early and strong anchorage, enhancing persistence and establishment probabilities. Seedling substrate preference documented here leads to expect a more successful sexual recruitment on hard bottoms compared with soft ones. This feature could have influenced P. oceanica patterns of colonization in past and present time. PMID:25928898

  9. Assessing Posidonia oceanica Seedling Substrate Preference: An Experimental Determination of Seedling Anchorage Success in Rocky vs. Sandy Substrates

    PubMed Central

    Alagna, Adriana; Fernndez, Toms Vega; Anna, Giovanni D; Magliola, Carlo; Mazzola, Salvatore; Badalamenti, Fabio

    2015-01-01

    In the last decades the growing awareness of the ecological importance of seagrass meadows has prompted increasing efforts to protect existing beds and restore degraded habitats. An in-depth knowledge of factors acting as major drivers of propagule settlement and recruitment is required in order to understand patterns of seagrass colonization and recovery and to inform appropriate management and conservation strategies. In this work Posidonia oceanica seedlings were reared for five months in a land-based culture facility under simulated natural hydrodynamic conditions to identify suitable substrates for seedling anchorage. Two main substrate features were investigated: firmness (i.e., sand vs. rock) and complexity (i.e., size of interstitial spaces between rocks). Seedlings were successfully grown in culture tanks, obtaining overall seedling survival of 93%. Anchorage was strongly influenced by substrate firmness and took place only on rocks, where it was as high as 89%. Anchorage occurred through adhesion by sticky root hairs. The minimum force required to dislodge plantlets attached to rocky substrates reached 23.830 N (equivalent to 2.43 kg), which would potentially allow many plantlets to overcome winter storms in the field. The ability of rocky substrates to retain seedlings increased with their complexity. The interstitial spaces between rocks provided appropriate microsites for seedling settlement, as seeds were successfully retained, and a suitable substrate for anchorage was available. In conclusion P. oceanica juveniles showed a clear-cut preference for hard substrates over the sandy one, due to the root system adhesive properties. In particular, firm and complex substrates allowed for propagule early and strong anchorage, enhancing persistence and establishment probabilities. Seedling substrate preference documented here leads to expect a more successful sexual recruitment on hard bottoms compared with soft ones. This feature could have influenced P. oceanica patterns of colonization in past and present time. PMID:25928898

  10. Why are there few seedlings beneath the myrmecophyte Triplaris americana?

    NASA Astrophysics Data System (ADS)

    Larrea-Alczar, Daniel M.; Simonetti, Javier A.

    2007-07-01

    We compared the relative importance of chemical alellopathy, pruning behaviour of resident ants and other non-related agents to ant-plant mutualism for seedling establishment beneath Triplaris americana L. (Polygonaceae), a myrmecophyte plant. We also included a preliminary analysis of effects of fragmentation on these ecological processes. Seeds and seedlings of Theobroma cacao L. (Sterculiaceae) were used as the target species in all experiments. Leaf-tissue extracts of the myrmecophyte plant did not inhibit germination of cacao seeds. Resident Pseudomyrmex triplarinus Weddell (Pseudomyrmecinae) ants did not remove seeds under the canopy of their host plants. The main seed consumer was the leaf-cutting ant Atta sexdens L. (Myrmicinae). Leaves of cacao seedlings were partially or totally pruned by Pseudomyrmex ants mainly in forest fragments studied. We offer evidence pointing to the possibility that the absence of seedlings beneath Triplaris may result from effects of both ant species. We discuss the benefits of pruning behaviour for the resident ant colony and the effects of ant-ant interactions on seedling establishment beneath this ant-plant system.

  11. Mycorrhizal networks affect ectomycorrhizal fungal community similarity between conspecific trees and seedlings.

    PubMed

    Bingham, Marcus A; Simard, Suzanne W

    2012-05-01

    Ectomycorrhizal (EM) networks (MN) are thought to be an important mode of EM fungal colonization of coniferous seedlings. How MNs affect EM communities on seedlings, and how this varies with biotic and abiotic factors, is integral to understanding their importance in seedling establishment. We examined EM fungal community similarity between mature trees and conspecific interior Douglas-fir (Pseudotsuga menziesii var. glauca) seedlings in two experiments where seed and nursery-grown seedlings originating from different locations were planted at various distances from trees along a climatic gradient. At harvest, trees shared 60% of their fungal taxa in common with outplanted seedlings and 77% with germinants, indicating potential for seedlings to join the network of residual trees. In both experiments, community similarity between trees and seedlings increased with drought. However, community similarity was lower among nursery seedlings growing at 2.5 m from trees when they were able to form an MN, suggesting MNs reduced seedling EM fungal richness. For field germinants, MNs resulted in lower community similarity in the driest climates. Distance from trees affected community similarity of nursery seedlings to trees, but there was no interaction of provenance with MNs in their effect on similarity in either nursery seedlings or field germinants as hypothesized. We conclude that MNs of trees influence EM colonization patterns of seedlings, and the strength of these effects increases with climatic drought. PMID:21822679

  12. Combined potentiating action of phytochemical(s) from Cinnamomum tamala and Aloe vera for their anti-diabetic and insulinomimetic effect using in vivo rat and in vitro NIH/3T3 cell culture system.

    PubMed

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

    2015-03-01

    The present investigation was undertaken to analyze the ethanolic extracts of leaves of Cinnamomum tamala and Aloe vera for their anti-diabetic and insulinomimitic effect by determining the levels of blood sugar, glycosylated hemoglobin, and serum lipid profile (total cholesterol, triglycerides, high density lipoprotein (HDL), and low density lipoprotein (LDL)) after daily administration of each alone and in combined at 250 mg/kg in alloxan (ALX)-induced diabetic rats. Treatment of diabetic rats with the extracts restored the elevated biochemical parameters significantly. The anti-diabetic effect further potentiated the insulin signaling pathway by co-administration of both extracts. The molecular mechanisms of modulating gene expression and cellular signaling through the insulin receptor were also evaluated on specific targets of the insulin signaling pathway, including insulin receptor substrate (IRS), phosphatidylinositol 3-kinase (PI3-K), AKT, and the glucose transporter (GLUT4) on NIH/3T3 cell line by western blotting, ELISA, semiquantitative RT-PCR, and real-time PCR. The active principle of both extracts revealed insulin mimicking effect as indicated by increased expression of pIRS1 and pAKT in time-dependent manner. There was no significant difference in PI3-K content between unchallenged and challenged groups. Enhanced expression of GLUT-4 transcript further suggested that the Cinnamomum and Aloe phytochemicals could serve as a good adjuvant in the present armamentarium of anti-diabetic drugs by either mimicking or improving insulin action. This study reveals that ethanolic extracts of C. tamala and A. vera have potent therapeutic efficacy and prospect for the development of phytomedicine for diabetes mellitus. PMID:25536877

  13. Seedling establishment of Ferocactus acanthodes in relation to drought

    SciTech Connect

    Jordan, P.W.; Nobel, P.S.

    1981-08-01

    The 30 smallest seedlings of Ferocactus acanthodes (Lem.) Britton and Rose (Cactaceae) at a canyon site in the northwestern Sonoran desert averaged 2.5 cm in height. Based on field studies of CO/sub 2/ exchange throughout the year, the estimated time of their germination was late summer 1976. To explan why so little establishment occurred in recent years, the length of lethal drought for seedlings of various ages was calculated from the seedling geometry (volume-to-surface ratio), dehydration tolerance, and transpiration rates. Individual years were identified which had sufficiently long growing seasons relative to the length of the subsequent droughts to allow establishment. Eight of the last 18 y were found to be suitable for establishment of F. acanthodes, the latest year being 1976.

  14. The induction of heat tolerance in black spruce seedlings

    SciTech Connect

    Colclough, M.; Blumwald, E. ); Colombo, S.J. )

    1990-05-01

    Heat conditioning of black spruce seedlings at 38{degree}C drastically reduced heat-induced damage of seedlings exposed to 49-52{degree}C. The pattern of protein synthesis during heat conditioning and heat stress was studied. Seedlings were in vivo labeled with ({sup 35}S)-methionine and protein fractions (soluble, mitochonrial and microsomal) were isolated from roots and needles. Proteins were separated by SDS-PAGE and identified by stainign and autoradiography. Several heat-shock proteins (HSP) were produced during heat conditioning and heat shock, but only few de novo synthesized proteins were specific to the heat conditioning treatments. Experiments used to distinguish between the putative HSP from those proteins specifically associated with the heat conditioning process will be presented and discussed.

  15. Nitrogen ion utilization by tulip poplar (Liriodendron tulipifera L. ) seedlings

    SciTech Connect

    Mann, L.K.

    1982-01-01

    Growth responses of one-year-old tulip poplar seedlings were determined for different nitrogen sources (HN/sub 4/NO/sub 3/, NH+/sub 4/, NO-/sub 3/, no nitrogen) at 336 ppm N in nutrient culture. At the end of three months, there were no significant differences in growth observed among treatments in terms of stem elongation, leaf area, and leaf size. After four months, however, seedlings of the NH/sub 4/NO/sub 3/ treatment exhibited significantly (P<0.05) greater growth (final weight gain and stem elongation) than all other nitrogen sorces. Growth was slightly less for the NO-/sub 3/ treatment plants, but compared with NH+/sub 4/ and no nitrogen treatment, both NH/sub 4/NO/sub 3/ and NO-/sub 3/ treatments exhibited significantly greater growth responses. NO-/sub 3/ is recommended as the sole nitrogen source, especially for small seedlings of tulip poplar.

  16. Active Ground Optical Remote Sensing for Improved Monitoring of Seedling Stress in Nurseries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Active ground optical remote sensing (AGORS) devices mounted on overhead irrigation booms could help to improve seedling quality by autonomously monitoring seedling stress. In contrast to traditionally used passive optical sensors, AGORS devices operate independently of ambient light conditions and ...

  17. Effect of sorghum seedlings and previous crop, on soil fluorescent pseudomonas spp.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aims: The hypotheses that sorghum seedlings [Sorghum bicolor (L.) Moench] varying in sorgoleone production will differentially modify soil microorganisms and will effect subsequent planting of wheat (Triticum aestivum L.) seedlings were tested. Methods: Wheat cultivar Lewjain, and sorghum genotypes ...

  18. Effect of soil bulk density on forest tree seedlings

    NASA Astrophysics Data System (ADS)

    Kormanek, Mariusz; Banach, Jacek; Sowa, Paweł

    2015-01-01

    The paper presents the results of an analysis of the influence of soil bulk density in a forest nursery plot on the growth and quality parameters of Scots pine and European beech seedlings. Particular density variants were obtained using a tractor device exerting controlled pressure on the soil, while field examinations were performed on an area of `Kłaj' forest nursery in Niepołomice Forest District. Three series of plots were prepared for each species, applying a unit pressure of the values of 50, 100, 150, 200, 250 kPa, corresponding to the dry bulk density in the range of 1.03-1.19 g cm-3, and control plots without the pressure. Seeds of the examined species were sown on the prepared plots, and after 6 months of growth the seedlings were subjected to biometric analysis determining differentiation in root neck diameter, length of the above-ground part and root system, as well as dry mass of particular parts of the plant. The quality of the seedlings was also determined using the method of Schmidt-Vogt. The results obtained show that the change in dry bulk density soil significantly affected most of the growth parameters of the examined seedlings. Especially high negative correlations were obtained for the length and dry mass of the root system. A significant influence of dry bulk density variant on all growth parameters of Scots pine seedlings, and on some parameters of European beech was demonstrated. An increase in soil bulk density clearly caused also a deterioration of European beech seedlings quality

  19. Microhabitat associations and seedling bank dynamics in a neotropical forest.

    PubMed

    Baraloto, Christopher; Goldberg, Deborah E

    2004-12-01

    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

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

    SciTech Connect

    Walters, R.S.

    1993-10-01

    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.

  1. Patterns of element concentrations help explain varietal differences in rice seedling vigor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seedling vigor is an important factor in rice production because it minimizes exposure of emerging seedlings to soil-borne diseases and promotes the early development of a uniform stand. Seedling vigor is influenced by both genetics and environment. In this study where plants of varying levels of se...

  2. Antioxidants and anti-stress compounds improve the survival of cryopreserved Arabidopsis seedlings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cryopreservation is a safe and cost-effective tool for the long-term storage of plant germplasm. Successful cryopreservation depends on suitable cryoprotection protocol. In Arabidopsis seedlings cryopreservation, the growth ability could be partly restored in 60-h seedlings, whereas 72-h seedlings d...

  3. SPATIAL EFFECTS OF RETENTION TREES ON MYCORRHIZAS OF DOUGLAS-FIR SEEDLINGS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Retention forestry places seedlings in proximity to residual trees, exposing seedlings to additional sources of ectomycorrhizal fungus (EMF) inoculum. To investigate this, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were planted near (2-6 m) and far (16-30 m) from 44- to 72-year-ol...

  4. DO RESIDUAL TREES HELP SEEDLINGS? EXPLORING THE NURSE-TREE EFFECT ON MYCORRHIZAL COLONIZATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Retention forestry places seedlings in proximity to residual trees, exposing seedlings to additional sources of ectomycorrhizal fungus (EMF) inoculum. To investigate this, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were planted near (16 m) from 44- to 72-year-old r...

  5. Physiological and phenological responses of oak seedlings to oak forest soil in the absence of trees.

    PubMed

    Dickie, Ian A; Montgomery, Rebecca A; Reich, Peter B; Schnitzer, Stefan A

    2007-01-01

    Established trees influence the growth and physiology of seedlings by altering above- and belowground conditions; however, tree influences on seedling physiology via belowground interactions are not well understood. We used soil transfers to an open field to examine the belowground influences of a Quercus ellipsoidalis E.J. Hill dominated forest on Q. ellipsoidalis seedling mycorrhizal infection, nutrient uptake, growth and photosynthesis over three years. After two years, seedlings planted with large quantities of forest soil (HF treatment) had greater leaf mass and foliar N concentrations than seedlings receiving smaller quantities of forest soil (LF) and control treatments. Mycorrhizal infection was greater in the HF treatment after one year compared with the LF and control treatments, with a positive correlation of foliar N and mycorrhizal infection in Year 2. There were marked effects of treatments on seedling spring phenology with HF seedlings breaking bud up to 17 days earlier than seedlings in the other treatments. The HF seedlings also had more rapid leaf expansion and larger leaves, and an increase in net photosynthetic rates. These results highlight complex linkages between above- and belowground physiology: forest soil had substantial effects on seedling physiology, including traits such as phenology that have previously been considered to be under aboveground control. Belowground influences of trees on conspecific seedlings may play a critical role in early seedling establishment. PMID:17169914

  6. Chromosome doubling of haploid maize seedlings by various in vitro treatments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A two-year study was conducted on methods for doubling haploid maize plants with elite temperate backgrounds following various seed treatments. Seedlings were treated with colchicine or other chemicals by 1) injecting plants and 2) a soak method using various seedling treatments. Treated seedlings...

  7. GENOMIC ANALYSIS OF THE EARLY RESPONSES OF DEVELOPING RICE SEEDLINGS TO COLD STRESS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most rice cultivars are highly sensitive to low temperatures particularly during the early stages of seedling establishment and flowering. Seedling cold tolerance, which is exhibited by many japonica cultivars is an important component of seedling vigor and yield potential. Given the biochemical c...

  8. Impact of corn gluten meal on direct-seeded vegetable seedling establishment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn gluten meal (CGM) may be used as a preemergent or preplant-incorporated herbicide for organic weed control of young developing or emerging weed seedlings; unfortunately, CGM can also adversely impact seedling survival of certain direct-seeded vegetable crops. Various vegetable crop seedlings re...

  9. Hessian fly (Mayetiola destructor) interactions with barley, rice, and wheat seedlings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A choice test revealed that Hessian fly adults deposited approximately three times more eggs on wheat seedlings than on barley or rice seedlings. On a barley seedling, 49.4% of eggs were deposited on either the abaxial leaf-surface or the coleoptile and first leaf-sheath (C&FLS), where newly hatche...

  10. Heat Stress Screening of Peanut Seedlings for Acquired Thermotolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this research was to develop a user-friendly and medium throughput laboratory protocol using acquired thermotolerance (ATT) in peanut seedlings as a measure of one mechanism of heat stress tolerance. Sixteen genotypes, including selected accessions of the U.S. peanut min...

  11. Regulation of Flavonoid Biosynthetic Genes in Germinating Arabidopsis Seedlings.

    PubMed Central

    Kubasek, WL; Shirley, BW; McKillop, A; Goodman, HM; Briggs, W; Ausubel, FM

    1992-01-01

    Many higher plants, including Arabidopsis, transiently display purple anthocyanin pigments just after seed germination. We observed that steady state levels of mRNAs encoded by four flavonoid biosynthetic genes, PAL1 (encoding phenylalanine ammonia-lyase 1), CHS (encoding chalcone synthase), CHI (encoding chalcone isomerase), and DFR (encoding dihydroflavonol reductase), were temporally regulated, peaking in 3-day-old seedlings grown in continuous white light. Except for the case of PAL1 mRNA, mRNA levels for these flavonoid genes were very low in seedlings grown in darkness. Light induction studies using seedlings grown in darkness showed that PAL1 mRNA began to accumulate before CHS and CHI mRNAs, which, in turn, began to accumulate before DFR mRNA. This order of induction is the same as the order of the biosynthetic steps in flavonoid biosynthesis. Our results suggest that the flavonoid biosynthetic pathway is coordinately regulated by a developmental timing mechanism during germination. Blue light and UVB light induction experiments using red light- and dark-grown seedlings showed that the flavonoid biosynthetic genes are induced most effectively by UVB light and that blue light induction is mediated by a specific blue light receptor. PMID:12297632

  12. Burst of ethylene upon horizontal placement of tomato seedlings

    NASA Technical Reports Server (NTRS)

    Harrison, M.; Pickard, B. G.

    1984-01-01

    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.

  13. WEED SEEDLING EMERGENCE AND MICROCLIMATE IN A TROPICAL ENVIRONMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropic ageratum (Ageratum conyzoides) is an important annual weed in tropical cropping systems. Better and more timely strategies for its control might be developed through a more thorough understanding of its emergence behavior. Seedling emergence of tropic ageratum was monitored periodically and s...

  14. Cotton seedling abrasion and recovery from wind blown sand

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Millions of hectares of crops are exposed to wind blown sand abrasion each year and in many instances the damage is thought to be severe enough to require replanting. The goal of this study was to determine the effects of wind blown sand abrasion duration on cotton (Gossypium hirsutum L.) seedlings...

  15. The vestigial root of dodder (Cuscuta pentagona) seedlings.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seedlings of dodder have no leaves nor cotyledons and the terminal root-like structure lasts only a few days before death. Structural and biochemical studies indicate that the terminal appendage of the dodder, although differentiated from the shoot, has few characteristics of root tissue. The root...

  16. Can seedling mineral composition predict rice grain nutritional value?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study investigated the possibility of using the mineral (ionomic) composition of rice (Oryza sativa L.) seedling leaves to predict varieties that accumulate large amounts of specific minerals in their grain. This information will be used for genetically improving the nutritional value of rice g...

  17. Identification of seedling cabbages and weeds using hyperspectral imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Target detectionis one of research focues for precision chemical application. This study developed a method to identify seedling cabbages and weeds using hyperspectral spectral imaging. In processing the image data, with ENVI software, after dimension reduction, noise reduction, de-correlation for h...

  18. Postanoxic Injury in Soybean (Glycine max) Seedlings 1

    PubMed Central

    VanToai, Tara T.; Bolles, Christopher S.

    1991-01-01

    The postanoxic injury, also known as reperfusion injury, is associated with the returning of anoxic tissues to normal atmosphere. Using tetrazolium chloride staining, ATP content, and seedling growth rate as indicators, we found that postanoxic injuries in soybean (Glycine max) seedlings were more severe after 1 and 2 hours of anoxia than after longer anoxic durations (3 to 5 hours). Anaerobic incubation of root tips in the presence of 100 mm ascorbate, an antioxidant and free radical-scavenging compound, alleviated the postanoxic injury associated with the short durations of anoxia. Extracts from soybean seedling roots returned to air from 1 hour of anoxia had an elevated capacity to produce superoxide radicals over extracts from postanoxic roots stressed for 3 or 5 hours. Activity of superoxide dismutase in soybean roots returned to air from 1 and 2 hours of anoxia was 30 to 50% lower than activities in roots returned to air from 5 hours of anoxia. Superoxide dismutase-specific transcripts were also lower in postanoxic roots stressed for 1 hour than in roots stressed for longer anoxic durations. The evidence suggested that the postanoxic injury of soybean roots after a short anoxic stress was associated with an increased superoxide radicals production capacity coupled with a reduced superoxide dismutase activity. Periods of anoxia of at least 3 hours were necessary for soybean seedlings to develop the ability to cope with postanoxic stress. ImagesFigure 4 PMID:16668439

  19. Seedling vigor in Beta vulgaris: The artistry of germination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Emergence and stand establishment through the first 10 weeks after planting continue to be primary concerns of sugar beet growers. Our goal is to understand the genes and genetics of seedling vigor in order to overcome beet’s inherent disadvantages of small seed size and encapsulation in a corky fru...

  20. Seedling emergence of horseweed in no-till

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Density of horseweed is increasing in no-till cropping systems because horseweed seed is transported by wind and seedlings can establish from seeds lying on the soil surface. Also, horseweed has developed resistance to commonly-used herbicides, thus control tactics are often ineffective. This repo...

  1. Can rice grain mineral concentrations be predicted at seedling stage?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The study investigated the possibility of using the mineral (ionomic) concentrations of rice (Oryza sativa L.) seedling leaves to predict genotypes that accumulate large amounts of certain minerals in their grains. This information will be used for genetically improving the nutritional value of rice...

  2. Utilization of Amygdalin during Seedling Development of Prunus serotina.

    PubMed

    Swain, E.; Poulton, J. E.

    1994-10-01

    Cotyledons of mature black cherry (Prunus serotina Ehrh.) seeds contain the cyanogenic diglucoside (R)-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 the atmosphere. Concomitantly, prunasin, which was not present in mature, ungerminated seeds, accumulated in the seedling epicotyls, hypocotyls, and cotyledons to levels approaching 4 [mu]mol per seedling. Whether this prunasin resulted from amygdalin hydrolysis remains unclear, however, because these organs also possess UDPG:mandelonitrile glucosyltransferase, which catalyzes de novo prunasin biosynthesis. The reduction in amygdalin levels was paralleled by declines in the levels of amygdalin hydrolase (AH), prunasin hydrolase (PH), mandelonitrile lyase (MDL), and [beta]-cyanoalanine synthase. At all stages of seedling development, AH and PH were localized by immunocytochemistry within the vascular tissues. In contrast, MDL occurred mostly in the cotyledonary parenchyma cells but was also present in the vascular tissues. Soon after imbibition, AH, PH, and MDL were found within protein bodies but were later detected in vacuoles derived from these organelles. PMID:12232341

  3. Soybean seedlings tolerate abrasion from air-propelled grit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New tools for controlling weeds would be useful for soybean production in organic systems. Air-propelled abrasive grit is one such tool that performs well for in-row weed control in corn, but crop safety in soybean is unknown. We examined responses to abrasion by corn-cob grit of soybean seedlings a...

  4. Phosphine-induced physiological and biochemical responses in rice seedlings.

    PubMed

    Mi, Lina; Niu, Xiaojun; Lu, Meiqing; Ma, Jinling; Wu, Jiandong; Zhou, Xingqiu

    2014-04-01

    Paddy fields have been demonstrated to be one of the major resources of atmospheric phosphine and may have both positive and negative effects on rice plants. To elucidate the physiological and biochemical responses of rice plants to phosphine, rice seedlings (30 d old) were selected as a model plant and were treated with different concentrations of phosphine (0, 1.4, 4.2, and 7.0 mg m(-3)). Antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), and lipid peroxidation measured via malondialdehyde (MDA) were determined as indicators of the physiological and biochemical responses of the rice seedlings to phosphine exposure. Increasing concentrations of phosphine treatment enhanced the activity of SOD, POD, and CAT. In addition, the MDA content increased with increasing concentrations of phosphine. These results suggested that antioxidant enzymes played important roles in protecting rice seedlings from ROS damage. Moreover, rice seedlings were able to cope with the oxidative stress induced by low concentrations of phosphine via an increase in antioxidant enzymatic activities. However, oxidative stress may not fully be prevented when the plants were exposed to higher concentrations of phosphine. PMID:24405968

  5. Heritability of some characteristics of Sorbus torminalis seedling.

    PubMed

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

    2007-08-15

    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

  6. [Characterization of growth-promoting rhizobacteria in Eucalyptus nitens seedlings].

    PubMed

    Angulo, Violeta C; Sanfuentes, Eugenio A; Rodrguez, Francisco; Sossa, Katherine E

    2014-01-01

    Rhizospheric and endophytic bacteria were isolated from the rizosphere and root tissue of Eucalyptus nitens. The objective of this work was to evaluate their capacity to promote growth in seedlings of the same species under greenhouse conditions. The isolates that improved seedling growth were identified and characterized by their capacity to produce indoleacetic acid (IAA), solubilize phosphates and increase 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. One hundred and five morphologically different strains were isolated, 15 of which promoted E. nitens seedling growth, significantly increasing the height (50%), root length (45%) as well as the aerial and root dry weight (142% and 135% respectively) of the plants. Bacteria belonged to the genus Arthrobacter, Lysinibacillus, Rahnella and Bacillus. Isolates A. phenanthrenivorans 21 and B. cereus 113 improved 3.15 times the emergence of E. nitens after 12 days, compared to control samples. Among isolated R. aquatilis, 78 showed the highest production of IAA (97.52.87 ?g/ml) in the presence of tryptophan and the highest solubilizer index (2.4) for phosphorus, while B. amyloliquefaciens 60 isolate was positive for ACC deaminase activity. Our results reveal the potential of the studied rhizobacteria as promoters of emergence and seedling growth of E. nitens, and their possible use as PGPR inoculants, since they have more than one mechanism associated with plant growth promotion. PMID:25576419

  7. Seedling Vigor in Beta vulgaris: The Artistry of Germination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seedling vigor and stand establishment are two problems that growers have struggled with for decades. The initial conditions that a germinating seed encounters, and its ability to deal with them, affect the rate at which germination occurs, the rate of mobilization of stored energy reserves that the...

  8. Oxygen sensing coordinates photomorphogenesis to facilitate seedling survival.

    PubMed

    Abbas, Mohamad; Berckhan, Sophie; Rooney, Daniel J; Gibbs, Daniel J; Vicente Conde, Jorge; Sousa Correia, Cristina; Bassel, George W; Marn-de la Rosa, Nora; Len, Jos; Alabad, David; Blzquez, Miguel A; Holdsworth, Michael J

    2015-06-01

    Successful emergence from the soil is essential for plant establishment in natural and farmed systems. It has been assumed that the absence of light in the soil is the preeminent signal perceived during early seedling development, leading to a distinct morphogenic plan (skotomorphogenesis) [1], characterized by traits providing an adaptive advantage until emergence and photomorphogenesis. These traits include suppressed chlorophyll synthesis, promotion of hypocotyl elongation, and formation of a closed apical hook that protects the stem cell niche from damage [2, 3]. However, absence of light by itself is not a sufficient environmental signal for early seedling development [4, 5]. Reduced oxygen levels (hypoxia) can occur in water-logged soils [6-8]. We therefore hypothesized that below-ground hypoxia may be an important, but thus far undiscovered, ecological component regulating seedling development. Here, we show that survival and establishment of seedlings following darkness depend on their ability to sense hypoxia, through enhanced stability of group VII Ethylene Response Factor (ERFVII) transcription factors. Hypoxia is perceived as a positive environmental component in diverse taxa of flowering plants, promoting maintenance of skotomorphogenic traits. Hypoxia greatly enhances survival once light is perceived, while oxygen is necessary for the subsequent effective completion of photomorphogenesis. Together with light perception, oxygen sensing therefore allows an integrated response to the complex and changing physical microenvironment encountered during early seedling growth. We propose that plants monitor the soil's gaseous environment after germination, using hypoxia as a key external cue to protect the stem cell niche, thus ensuring successful rapid establishment upon emergence above ground. PMID:25981794

  9. Starch bioengineering affects cereal grain germination and seedling establishment

    PubMed Central

    Hebelstrup, Kim H.; Blennow, Andreas

    2014-01-01

    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 β-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. α-Amylase activity was distinctly suppressed in both the HP and the AO lines. Pre-germination β-amylase deposition was low in the AO grains and β-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. PMID:24642850

  10. Effects of seed traits variation on seedling performance of the invasive weed, Ambrosia artemisiifolia L.

    NASA Astrophysics Data System (ADS)

    Ortmans, William; Mahy, Grégory; Monty, Arnaud

    2016-02-01

    Seedling performance can determine the survival of a juvenile plant and impact adult plant performance. Understanding the factors that may impact seedling performance is thus critical, especially for annuals, opportunists or invasive plant species. Seedling performance can vary among mothers or populations in response to environmental conditions or under the influence of seed traits. However, very few studies have investigated seed traits variations and their consequences on seedling performance. Specifically, the following questions have been addressed by this work: 1) How the seed traits of the invasive Ambrosia artemisiifolia L. vary among mothers and populations, as well as along the latitude; 2) How do seed traits influence seedling performance; 3) Is the influence on seedlings temperature dependent. With seeds from nine Western Europe ruderal populations, seed traits that can influence seedling development were measured. The seeds were sown into growth chambers with warmer or colder temperature treatments. During seedling growth, performance-related traits were measured. A high variability in seed traits was highlighted. Variation was determined by the mother identity and population, but not latitude. Together, the temperature, population and the identity of the mother had an effect on seedling performance. Seed traits had a relative impact on seedling performance, but this did not appear to be temperature dependent. Seedling performance exhibited a strong plastic response to the temperature, was shaped by the identity of the mother and the population, and was influenced by a number of seed traits.

  11. Biological seed priming mitigates the effects of water stress in sunflower seedlings.

    PubMed

    Singh, Narsingh Bahadur; Singh, Deepmala; Singh, Amit

    2015-04-01

    The sunflower (Helianthus annuus L. cv. PAC 36) seedlings were inoculated with plant growth promoting rhizobacteria (PGPR), viz. Azotobacter chroococcum (A+), Bacillus polymyxa (B+), separately and in combination of the two (AB+). Relative water content and seedling growth were maximum in AB+ seedlings under control. Water stress significantly decreased the RWC, growth and dry mass of non-inoculated seedlings. However, inoculated seedlings maintained higher growth even under water stress. Pigments and protein contents decreased under water stress, but higher amount of the same was observed in stressed AB+ seedlings. Enhanced activity of nitrate reductase was recorded in AB+ seedlings with maximum in control. Water stress significantly decreased the nitrate reductase activity. A significant increase in the activity of superoxide dismutase (SOD) in leaves was recorded under water stress except in B+ with maximum increase in non-inoculated seedlings. Catalase (CAT) activity decreased in stressed non-inoculated seedlings while increased in the leaves of A+ and AB+ seedlings. Almost similar trends were recorded for both leaves and cotyledons. PGPR improved the water status in stressed seedlings and thereby physiological and biochemical parameters and thus ameliorated the severe effects of water stress. PMID:25964714

  12. Effects of arbuscular mycorrhizae on water stress tolerance of big sagebrush seedlings

    SciTech Connect

    Schuman, G.E.; Stahl, P.D.; Williams, S.E.; Frost, S.M.

    1998-12-31

    Reestablishment of Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) on mined lands has been difficult in the past even though it is widespread in the western US. Its reestablishment on mined lands has recently become law where wildlife is one of the post-mining land uses and it represented the primary premining shrub species. One hypothesis thought to contribute to its difficult reestablishment is the reduce lack of mycorrhizae inoculum present in the disturbed topsoil and the resulting effect on the seedling`s ability to extract water from the soil under the arid/semiarid climate of this region. A greenhouse study was conducted to evaluate the effect of mycorrhizae on sagebrush seedling water stress tolerance. Seedling ages evaluated ranged from 30 to 150 days. Seedling survival was greater for mycorrhizal seedlings compared to non-mycorrhizal seedlings when soil moisture tension was {minus}2.5 to {minus}3.8 MPa. At all ages, the degree of soil dryness necessary to cause sagebrush seedling mortality was significantly greater for mycorrhizal than non-mycorrhizal seedlings. Seedling age and mycorrhizal infection exhibited a significant statistical interaction; suggesting that as the sagebrush seedling aged, the benefits of arbuscular mycorrhizae (AM) increased the plants water stress tolerance. These findings lead the authors to conclude that topsoil management that prevents/reduces the loss of AM inoculum in the topsoil will significantly enhance the success of sagebrush establishment on mined lands.

  13. Neighborhood and community interactions determine the spatial pattern of tropical tree seedling survival.

    PubMed

    Queenborough, Simon A; Burslem, David F R P; Garwood, Nancy C; Valencia, Renato

    2007-09-01

    Factors affecting survival and recruitment of 3531 individually mapped seedlings of Myristicaceae were examined over three years in a highly diverse neotropical rain forest, at spatial scales of 1-9 m and 25 ha. We found convincing evidence of a community compensatory trend (CCT) in seedling survival (i.e., more abundant species had higher seedling mortality at the 25-ha scale), which suggests that density-dependent mortality may contribute to the spatial dynamics of seedling recruitment. Unlike previous studies, we demonstrate that the CCT was not caused by differences in microhabitat preferences or life history strategy among the study species. In local neighborhood analyses, the spatial autocorrelation of seedling survival was important at small spatial scales (1-5 m) but decayed rapidly with increasing distance. Relative seedling height had the greatest effect on seedling survival. Conspecific seedling density had a more negative effect on survival than heterospecific seedling density and was stronger and extended farther in rare species than in common species. Taken together, the CCT and neighborhood analyses suggest that seedling mortality is coupled more strongly to the landscape-scale abundance of conspecific large trees in common species and the local density of conspecific seedlings in rare species. We conclude that negative density dependence could promote species coexistence in this rain forest community but that the scale dependence of interactions differs between rare and common species. PMID:17918403

  14. Pathogenicity of the pinewood nematode, Bursaphelenchus xylophilus, to Japanese larch, Larix kaempferi, seedlings.

    PubMed

    Mamiya, Y; Shoji, T

    2009-06-01

    Pathogenicity of the pine wood nematode, Bursaphelenchus xylophilus, to Japanese larch, Larix kaempferi, seedlings was tested with inoculation experiments under nursery conditions. Water suspensions of nematodes (mixed stages cultured on Botrytis cinerea or dispersal fourth-stage juveniles (DJ4) extracted from the adult Japanese pine sawyer, Monochamus alternatus) were injected into the stems of 2- and 3-year-old Japanese larch and Japanese black pine, Pinus thunbergii, seedlings growing in a nursery. In another treatment, Japanese pine sawyer adults holding DJ4 were released under a net that covered the upper half of the seedlings. Regardless of nematode inoculation method, Japanese larch seedlings were as susceptible as Japanese black pine seedlings to B. xylophilus under nursery conditions. The rate of disease development was similar on larch and pine seedlings. Nematode population densities were lower in the stems of dead larch seedlings than in the stems of dead pine seedlings. Histopathological observations revealed that the distribution of nematodes in the stems of dead larch seedlings was mostly limited to the cortex, phloem and cambial zone. Traumatic resin canal formation was one of the most characteristic symptoms in larch seedlings which was dissimilar to that in pine seedlings. PMID:22661789

  15. Hessian fly (Diptera: Cecidomyiidae) interactions with barley, rice, and wheat seedlings.

    PubMed

    Chen, Ming-Shun; Liu, Xuming; Wang, Haiyan; El-Bouhssini, Mustapha

    2009-08-01

    A choice test revealed that Hessian fly, Mayetiola destructor (Say) (Diptera: Cecidomyiidae), adults deposited approximately 3 times more eggs on wheat (Triticum spp.), seedlings than on barley (Hordeum spp.) or rice, Oryza sativa L., seedlings. On a barley seedling, 49.4% of eggs were deposited on either the abaxial leaf surface or the coleoptile and first leaf sheath (C&FLS), where newly hatched larvae die due to their inability to migrate into the interspace between leaf sheaths. In comparison, only 14% of eggs were deposited on the abaxial leaf surface or C&FLS on a wheat seedling. The average death rate of Hessian fly larvae in seedlings of an apparently susceptible barley line was 60%, compared with only 10% in seedlings of a susceptible wheat cultivar. The development of Hessian fly larvae was also much slower in barley seedlings than in wheat seedlings. It took 12 d for Hessian fly larvae to finish the first and second instars in susceptible barley seedlings, compared with 10 d in susceptible wheat seedlings under the same conditions. These results indicate that barley is not a good host for the Hessian fly. Our results also confirmed that rice is a nonhost for the Hessian fly. The resistance mechanism in rice was different from that in R gene resistant wheat. Hessian fly larvae grew a little and died more slowly in rice seedlings, whereas Hessian fly larvae died quickly without growth in resistant wheat. PMID:19736782

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

    PubMed

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

    2009-09-01

    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

  17. Effects of host plant exposure to cadmium on mycorrhizal infection and soluble carbohydrate levels of Pinus sylvestris seedlings.

    PubMed

    Kim, C-G; Power, S A; Bell, J N B

    2004-09-01

    In a Cd-contaminated environment, not only mature trees but also their seeds and young seedlings can be exposed to Cd. Cadmium taken up by young seedlings may influence mycorrhizal infection, which might in turn influence resistance to Cd toxicity. In order to eliminate soil-mediated responses of mycorrhizal infection to Cd, Pinus sylvestris seedlings were exposed to Cd prior to fungal inoculation and replanted to clean substrates with fungal inoculum. Cadmium pretreatment reduced the proportion of living mycorrhizal short roots of seedlings inoculated with Paxillus involutus. However, no such effect was observed for seedlings inoculated with Suillus bovinus and Rhizopogon subcaerulescens. Therefore, infection by P. involutus appeared to be affected by Cd taken up by seedlings. Overall stem length and biomass of the seedlings were reduced by Cd pretreatment. Infection by S. bovinus and R. subcaerulescens increased stem length and biomass of the seedlings. Root soluble carbohydrate concentrations were lower in mycorrhizal seedlings than non-mycorrhizal seedlings. PMID:15234095

  18. Molecular Mechanism of Cinnamomum verum Component Cuminaldehyde Inhibits Cell Growth and Induces Cell Death in Human Lung Squamous Cell Carcinoma NCI-H520 Cells In Vitro and In Vivo.

    PubMed

    Yang, Shu-Mei; Tsai, Kuen-Daw; Wong, Ho-Yiu; Liu, Yi-Heng; Chen, Ta-Wei; Cherng, Jonathan; Hsu, Kwang-Ching; Ang, Yao-Uh; Cherng, Jaw-Ming

    2016-01-01

    Cinnamomum verum is used to make the spice cinnamon and has been used as a traditional Chinese herbal medicine. We evaluated the effects and the molecular mechanisms of cuminaldehyde (CuA), a constituent of the bark of Cinnamomum verum, on human lung squamous cell carcinoma NCI-H520 cells. Specifically, cell viability was evaluated by colorimetric assay; cytotoxicity by LDH release; apoptosis was determined by Western blotting, and morphological analysis with, acridine orange and neutral red stainings and comet assay; topoisomerase I activity was assessed using assay based upon DNA relaxation and topoisomerase II by DNA relaxation plus decatentation of kinetoplast DNA; lysosomal vacuolation and volume of acidic compartments (VAC) were evaluated with neutral red staining. The results show that CuA suppressed proliferation and induced apoptosis as indicated by an up-regulation of pro-apoptotic bax and bak genes and a down-regulation of anti-apoptotic bcl-2 and bcl-XL genes, mitochondrial membrane potential loss, cytochrome c release, activation of caspase 3 and 9, and morphological characteristics of apoptosis, including blebbing of the plasma membrane, nuclear condensation, fragmentation, apoptotic body formation, and comet with elevated tail intensity and moment. In addition, CuA also induced lysosomal vacuolation with increased VAC, cytotoxicity, as well as suppressions of both topoisomerase I and II activities in a dose-dependent manner. Further study revealed the growth-inhibitory effect of CuA was also evident in a nude mice model. Taken together, the data suggest that the growth-inhibitory effect of CuA against NCI-H520 cells is accompanied by downregulations of proliferative control involving apoptosis and both topoisomerase I and II activities, and upregulation of lysosomal with increased VAC and cytotoxicity. Similar effects were found in other cell lines, including human lung adenocarcinoma A549 cells and colorectal adenocarcinoma COLO 205 (results not shown). Our data suggest that CuA could be a potential agent for anticancer therapy. PMID:26918037

  19. Molecular Mechanism of Cinnamomum verum Component Cuminaldehyde Inhibits Cell Growth and Induces Cell Death in Human Lung Squamous Cell Carcinoma NCI-H520 Cells In Vitro and In Vivo

    PubMed Central

    Yang, Shu-mei; Tsai, Kuen-daw; Wong, Ho-Yiu; Liu, Yi-Heng; Chen, Ta-Wei; Cherng, Jonathan; Hsu, Kwang-Ching; Ang, Yao-Uh; Cherng, Jaw-Ming

    2016-01-01

    Cinnamomum verum is used to make the spice cinnamon and has been used as a traditional Chinese herbal medicine. We evaluated the effects and the molecular mechanisms of cuminaldehyde (CuA), a constituent of the bark of Cinnamomum verum, on human lung squamous cell carcinoma NCI-H520 cells. Specifically, cell viability was evaluated by colorimetric assay; cytotoxicity by LDH release; apoptosis was determined by Western blotting, and morphological analysis with, acridine orange and neutral red stainings and comet assay; topoisomerase I activity was assessed using assay based upon DNA relaxation and topoisomerase II by DNA relaxation plus decatentation of kinetoplast DNA; lysosomal vacuolation and volume of acidic compartments (VAC) were evaluated with neutral red staining. The results show that CuA suppressed proliferation and induced apoptosis as indicated by an up-regulation of pro-apoptotic bax and bak genes and a down-regulation of anti-apoptotic bcl-2 and bcl-XL genes, mitochondrial membrane potential loss, cytochrome c release, activation of caspase 3 and 9, and morphological characteristics of apoptosis, including blebbing of the plasma membrane, nuclear condensation, fragmentation, apoptotic body formation, and comet with elevated tail intensity and moment. In addition, CuA also induced lysosomal vacuolation with increased VAC, cytotoxicity, as well as suppressions of both topoisomerase I and II activities in a dose-dependent manner. Further study revealed the growth-inhibitory effect of CuA was also evident in a nude mice model. Taken together, the data suggest that the growth-inhibitory effect of CuA against NCI-H520 cells is accompanied by downregulations of proliferative control involving apoptosis and both topoisomerase I and II activities, and upregulation of lysosomal with increased VAC and cytotoxicity. Similar effects were found in other cell lines, including human lung adenocarcinoma A549 cells and colorectal adenocarcinoma COLO 205 (results not shown). Our data suggest that CuA could be a potential agent for anticancer therapy. PMID:26918037

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

    PubMed

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

    2007-03-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    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.

  2. Effects of invasive rats and burrowing seabirds on seeds and seedlings on New Zealand islands.

    PubMed

    Grant-Hoffman, Madeline N; Mulder, Christa P H; Bellingham, Peter J

    2010-04-01

    Rats (Rattus rattus, Rattus norvegicus, Rattus exulans) are important invaders on islands. They alter vegetation indirectly by preying on burrowing seabirds. These seabirds affect vegetation through nutrient inputs from sea to land and physical disturbance through trampling and burrowing. Rats also directly affect vegetation though consumption of seeds and seedlings. Seedling communities on northern New Zealand islands differ in composition and densities among islands which have never been invaded by rats, are currently invaded by rats, or from which rats have been eradicated. We conducted experimental investigations to determine the mechanisms driving these patterns. When the physical disturbance of seabirds was removed, in soils collected from islands and inside exclosures, seedling densities increased with seabird burrow density. For example, seedling densities inside exclosures were 10 times greater than those outside. Thus the negative effects of seabirds on seedlings, by trampling and uprooting, overwhelm the potentially beneficial effects of high levels of seed germination, seedling emergence, and possibly seed production, which result from seed burial and nutrient additions. Potential seedling density was reduced on an island where rats were present, germination of seeds from soils of this island was approximately half that found on other islands, but on this island seedling density inside exclosures was 7 times the density outside. Although the total negative effects of seabirds and rats on seedling densities are similar (reduced seedling density), the differences in mechanisms and life stages affected result in very different filters on the plant community. PMID:19921273

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

    USGS Publications Warehouse

    Bowers, Janice E.; Pierson, E.A.

    2001-01-01

    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.

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

    PubMed

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

    2004-10-01

    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

  5. Seed predation by Neotropical rain forest mammals increases diversity in seedling recruitment.

    PubMed

    Paine, C E Timothy; Beck, Harald

    2007-12-01

    Seed dispersal and seedling recruitment (the transition of seeds to seedlings) set the spatiotemporal distribution of new individuals in plant communities. Many terrestrial rain forest mammals consume post-dispersal seeds and seedlings, often inflicting density-dependent mortality. In part because of density-dependent mortality, diversity often increases during seedling recruitment, making it a critical stage for species coexistence. We determined how mammalian predators, adult tree abundance, and seed mass interact to affect seedling recruitment in a western Amazonian rain forest. We used exclosures that were selectively permeable to three size classes of mammals: mice and spiny rats (weighing <1 kg), medium-sized rodents (1-12 kg), and large mammals (20-200 kg). Into each exclosure, we placed seeds of 13 tree species and one canopy liana, which varied by an order of magnitude in adult abundance and seed mass. We followed the fates of the seeds and resulting seedlings for at least 17 months. We assessed the effect of each mammalian size class on seed survival, seedling survival and growth, and the density and diversity of the seedlings that survived to the end of the experiment. Surprisingly, large mammals had no detectable effect at any stage of seedling recruitment. In contrast, small- and medium-sized mammals significantly reduced seed survival, seedling survival, and seedling density. Furthermore, predation by small mammals increased species richness on a per-stem basis. This increase in diversity resulted from their disproportionately intense predation on common species and large-seeded species. Small mammals thereby generated a rare-species advantage in seedling recruitment, the critical ingredient for frequency dependence. Predation by small (and to a lesser extent, medium-sized) mammals on seeds and seedlings significantly increases tree species diversity in tropical forests. This is the first long-term study to dissect the effects of various mammalian predators on the recruitment of a diverse set of tree species. PMID:18229842

  6. A technique for collection of exudate from pea seedlings

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

  7. Incorporation of cytokinins into DNA of wheat seedlings

    SciTech Connect

    Kudryashova, I.B.; Vanyushin, B.F.

    1986-08-20

    After incubation of wheat seedlings with (/sup 3/H)benzylaminopurine or (8-/sup 3/H)zeathin appreciable radioactivity was found in the purine bases of DNA, mainly in adenine. Moreover, as a result of acid hydrolysis labeled cytokinins were isolated from labeled highly purified preparations of the total DNA of wheat seedlings. Their radioactivity constituted 5-10% of the radioactivity of the adenine bases in the DNA. After mild acid hydrolysis (/sup 3/H)benzylaminopurine and (/sup 3/H)zeathin were found in the deoxyribonucleoside fraction obtained from cytokinin-labeled DNA. Thus, different cytokinins (N/sup 6/-substituted adenine derivatives) are covalently incorporated into the newly synthesized DNA of plants.

  8. Growth distribution during phototropism of Arabidopsis thaliana seedlings

    SciTech Connect

    Orbovic, V.; Poff, K.L. )

    1993-09-01

    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.

  9. Proline accumulation is inhibitory to Arabidopsis seedlings during heat stress.

    PubMed

    Lv, Wei-Tao; Lin, Bin; Zhang, Min; Hua, Xue-Jun

    2011-08-01

    The effect of proline (Pro) accumulation on heat sensitivity was investigated using transgenic Arabidopsis (Arabidopsis thaliana) plants ectopically expressing the Δ(1)-pyrroline-5-carboxylate synthetase 1 gene (AtP5CS1) under the control of a heat shock protein 17.6II gene promoter. During heat stress, the heat-inducible expression of the AtP5CS1 transgene was capable of enhancing Pro biosynthesis. Twelve-day-old seedlings were first treated with heat at 37 °C for 24 h to induce Pro and then were stressed at 50 °C for 4 h. After recovery at 22 °C for 96 h, the growth of Pro-overproducing plants was significantly more inhibited than that of control plants that do not accumulate Pro, manifested by lower survival rate, higher ion leakage, higher reactive oxygen species (ROS) and malondialdehyde levels, and increased activity of the Pro/P5C cycle. The activities of antioxidant enzymes superoxide dismutase, guaiacol peroxidase, and catalase, but not those of glutathione reductase and ascorbate peroxidase, increased in all lines after heat treatment, but the increase was more significant in Pro-overproducing seedlings. Staining with MitoSox-Red, reported for being able to specifically detect superoxide formed in mitochondria, showed that Pro accumulation during heat stress resulted in elevated levels of ROS in mitochondria. Interestingly, exogenous abscisic acid (ABA) and ethylene were found to partially rescue the heat-sensitive phenotype of Pro-overproducing seedlings. Measurement of ethylene and ABA levels further confirmed that these two hormones are negatively affected in Pro-overproducing seedlings during heat stress. Our results indicated that Pro accumulation under heat stress decreases the thermotolerance, probably by increased ROS production via the Pro/P5C cycle and inhibition of ABA and ethylene biosynthesis. PMID:21670222

  10. Turnover of dhurrin in green sorghum seedlings. [Sorghum bicolor

    SciTech Connect

    Adewusi, S.R.A. )

    1990-11-01

    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.

  11. The significance of glucosinolates for sulfur storage in Brassicaceae seedlings

    PubMed Central

    Aghajanzadeh, Tahereh; Hawkesford, Malcolm J.; De Kok, Luit J.

    2014-01-01

    Brassica juncea seedlings contained a twofold higher glucosinolate content than B. rapa and these secondary sulfur compounds accounted for up to 30% of the organic sulfur fraction. The glucosinolate content was not affected by H2S and SO2 exposure, demonstrating that these sulfur compounds did not form a sink for excessive atmospheric supplied sulfur. Upon sulfate deprivation, the foliarly absorbed H2S and SO2 replaced sulfate as the sulfur source for growth of B. juncea and B. rapa seedlings. The glucosinolate content was decreased in sulfate-deprived plants, though its proportion of organic sulfur fraction was higher than that of sulfate-sufficient plants, both in absence and presence of H2S and SO2. The significance of myrosinase in the in situ turnover in these secondary sulfur compounds needs to be questioned, since there was no direct co-regulation between the content of glucosinolates and the transcript level and activity of myrosinase. Evidently, glucosinolates cannot be considered as sulfur storage compounds upon exposure to excessive atmospheric sulfur and are unlikely to be involved in the re-distribution of sulfur in B. juncea and B. rapa seedlings upon sulfate deprivation. PMID:25566279

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

    PubMed

    Xu, Qiu-Man; Chen, Hong

    2011-09-01

    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

  13. Organic Matter Loading Affects Lodgepole Pine Seedling Growth

    NASA Astrophysics Data System (ADS)

    Wei, Xiaohua; Li, Qinglin; Waterhouse, M. J.; Armleder, H. M.

    2012-06-01

    Organic matter plays important roles in returning nutrients to the soil, maintaining forest productivity and creating habitats in forest ecosystems. Forest biomass is in increasing demand for energy production, and organic matter has been considered as a potential supply. Thus, an important management question is how much organic matter should be retained after forest harvesting to maintain forest productivity. To address this question, an experimental trial was established in 1996 to evaluate the responses of lodgepole pine seedling growth to organic matter loading treatments. Four organic matter loading treatments were randomly assigned to each of four homogeneous pine sites: removal of all organic matter on the forest floor, organic matter loading quantity similar to whole-tree-harvesting residuals left on site, organic matter loading quantity similar to stem-only-harvesting residuals, and organic matter loading quantity more similar to what would be found in disease- or insect-killed stands. Our 10-year data showed that height and diameter had 29 and 35 % increase, respectively, comparing the treatment with the most organic matter loading to the treatment with the least organic matter loading. The positive response of seedling growth to organic matter loading may be associated with nutrients and/or microclimate change caused by organic matter, and requires further study. The dynamic response of seedling growth to organic matter loading treatments highlights the importance of long-term studies. Implications of those results on organic matter management are discussed in the context of forest productivity sustainability.

  14. Salt pretreatment enhance salt tolerance in Zea mays L. seedlings.

    PubMed

    Tajdoost, S; Farboodnia, T; Heidari, R

    2007-06-15

    Recent molecular studies show that genetic factors of salt tolerance in halophytes exist in glycophytes too, but they are not active. If these plants expose to low level salt stress these factors may become active and cause plants acclimation to higher salt stresses. So because of the importance of these findings in this research the effect of salt pretreatment has been examined in Zea mays seedlings. To do the experiment four day old Zea mays seedlings (Var. single cross 704) pretreated with 50 mM NaCl for the period of 20 h. Then they were transferred to 200 and 300 mM NaCl for 48 h. At the end of treatment roots and shoots of seedlings were harvested separately. The changes of K+ -leakage, the amount of malondialdehyde, proline, soluble sugars and the Hill reaction rate were analyzed. The results indicated that the amount of K+ -leakage and malondialdehyde (MDA) have been increased because of salt-induced lipid peroxidation and membrane unstability. Soluble sugars and proline as osmoregulators has been increased in stress condition and in pretreated plants with NaCl were the highest. The rate of Hill reaction was reduced significantly in stressed plants. Therefore we concluded that salt stress causes serious physiological and biochemical damages in plants and salt pretreatment enhances tolerance mechanisms of plants and help them to tolerate salt stress and grow on salty environments. PMID:19093451

  15. Effects of gravel mulch on emergency of galleta grass seedlings

    SciTech Connect

    Winkel, V.K.; Medrano, J.C.; Stanley, C.; Walo, M.D.

    1993-02-01

    Gravel mulches show promise as effective material on the US Dept. of Energy Nevada Test Site for stabilizing erosive soils and aiding plant establishment by conserving soil water. A greenhouse study was implemented to determine the effects of gravel mulch on seedling emergence and soil water, and optimal depths of gravel for various native plant species. Greenhouse flats were sown with seeds of nine species of native grasses, forbs, and shrubs. The flats were then treated with a variety of mulch treatments including, no mulch, a 1-cm layer of soil over seeds, and 2 to 3-cm and 4 to 5-cm layers of 3 to 25-mm mixed gravel. Superimposed over these treatments were 3 irrigation treatments. Seedling density data was collected daily, and soil water was monitored daily with the gravimetric method. This study showed that under a variety of soil water conditions, a 2--3 cm gravel layer may aid emergence of galleta grass. Results from this study also demonstrated that a deeper layer of gravel (4--5 cm) prohibits emergence, probably because it acts as a physical barrier to the seedlings. Galleta grass emergence can be used as a model for how other species might respond to these seedbed and irrigation treatments, provided they have adequate germination and are exposed to similar environmental conditions.

  16. Phytotoxicity of arsenic compounds on crop plant seedlings.

    PubMed

    Yoon, Youngdae; Lee, Woo-Mi; An, Youn-Joo

    2015-07-01

    The effects of inorganic and organic arsenic on the germination and seedling growth of 10 crop plants were investigated to elucidate the relationship between toxicity and the arsenic chemical states. Two types of soils, soil A and B, were also tested to determine how physicochemical properties of soils were related to toxicity of arsenic and the sensitivity of the plants. All tested plant species, except mung bean and cucumber, showed inhibition of germination by two types of inorganic arsenic, arsenite, and arsenate, while the organic arsenic compound, dimethylarsinic acid (DMA), had no inhibitory effects on plants in soil A. In contrast, the growth of seedlings of all 10 plant species was sensitive to the presence of arsenic. The sensitivity of the plants toward inorganic arsenic compounds showed similar trends but differed for DMA. Overall, seedling growth was a more sensitive endpoint to arsenic toxicity than germination, and the relative toxicity of arsenic compounds on plants was arsenite > DMA > arsenate. Interestingly, the sensitivity of wheat varied significantly when the soil was changed, and the DMA was most toxic rather than arsenite in soil B. Thus, the systematic study employed here provides insights into the mechanisms of arsenic toxicity in different plant species and the role of physicochemical properties of soils. PMID:25791266

  17. Cinnamomum verum Component 2-Methoxycinnamaldehyde: A Novel Anticancer Agent with Both Anti-Topoisomerase I and II Activities in Human Lung Adenocarcinoma A549 Cells In Vitro and In Vivo.

    PubMed

    Wong, Ho-Yiu; Tsai, Kuen-Daw; Liu, Yi-Heng; Yang, Shu-Mei; Chen, Ta-Wei; Cherng, Jonathan; Chou, Kuo-Shen; Chang, Chen-Mei; Yao, Belen T; Cherng, Jaw-Ming

    2016-02-01

    Cinnamomum verum is used to make the spice cinnamon and has been used as a traditional Chinese herbal medicine. We evaluated the anticancer effect of 2-methoxycinnamaldehyde (2-MCA), a constituent of the bark of the plant, and its underlying molecular biomarkers associated with carcinogenesis in human lung adenocarcinoma A549 cells. The results show that 2-MCA suppressed proliferation and induced apoptosis as indicated by an upregulation of pro-apoptotic Bax and Bak genes and downregulation of anti-apoptotic Bcl-2 and Bcl-XL genes, mitochondrial membrane potential loss, cytochrome c release, activation of caspase-3 and -9, and morphological characteristics of apoptosis, including plasma membrane blebbing and long comet tail. In addition, 2-MCA also induced lysosomal vacuolation with increased volume of acidic compartment (VAC) and suppressions of nuclear transcription factors nuclear factor-?B (NF-?B) and both topoisomerase I and II activities. Further study reveals that the growth-inhibitory effect of 2-MCA was also evident in a nude mice model. Taken together, the data suggest that the growth-inhibitory effect of 2-MCA against A549 cells is accompanied by downregulations of NF-?B binding activity and proliferative control involving apoptosis and both topoisomerase I and II activities, together with an upregulation of lysosomal vacuolation and VAC. Our data suggest that 2-MCA could be a potential agent for anticancer therapy. Copyright 2015 John Wiley & Sons, Ltd. PMID:26676220

  18. Effect of a Vietnamese Cinnamomum cassia essential oil and its major component trans-cinnamaldehyde on the cell viability, membrane integrity, membrane fluidity, and proton motive force of Listeria innocua.

    PubMed

    Trinh, Nga-Thi-Thanh; Dumas, Emilie; Thanh, Mai Le; Degraeve, Pascal; Ben Amara, Chedia; Gharsallaoui, Adem; Oulahal, Nadia

    2015-04-01

    The antibacterial mechanism of a Cinnamomum cassia essential oil from Vietnam and of its main component (trans-cinnamaldehyde, 90% (m/m) of C. cassia essential oil) against a Listeria innocua strain was investigated to estimate their potential for food preservation. In the presence of C. cassia essential oil or trans-cinnamaldehyde at their minimal bactericidal concentration (2700 ?gmL(-1)), L. innocua cells fluoresced green after staining with Syto9 and propidium iodide, as observed by epifluorescence microscopy, suggesting that the perturbation of membrane did not cause large pore formation and cell lysis but may have introduced the presence of viable but nonculturable bacteria. Moreover, the fluidity, potential, and intracellular pH of the cytoplasmic membrane were perturbed in the presence of the essential oil or trans-cinnamaldehyde. However, these membrane perturbations were less severe in the presence of trans-cinnamaldehyde than in the presence of multicomponent C. cassia essential oil. This indicates that in addition to trans-cinnamaldehyde, other minor C. cassia essential oil components play a major role in its antibacterial activity against L. innocua cells. PMID:25728340

  19. Root graviresponsiveness and columella cell structure in carotenoid-deficient seedlings of Zea mays

    NASA Technical Reports Server (NTRS)

    Moore, R.; McClelen, C. E.

    1985-01-01

    Root graviresponsiveness in normal and carotenoid-deficient mutant seedlings of Zea mays was not significantly different. Columella cells in roots of mutant seedlings were characterized by fewer, smaller, and a reduced relative volume of plastids as compared to columella cells of normal seedlings. Plastids in columella cells of mutant seedlings possessed reduced amounts of starch. Although approximately 10 per cent of the columella cells in mutant seedlings lacked starch, their plastids were located at the bottom of the cell. These results suggest that (i) carotenoids are not necessary for root gravitropism, (ii) graviresponsiveness is not necessarily proportional to the size, number, or relative volume of plastids in columella cells, and (iii) sedimentation of plastids in columella cells may not result directly from their increased density due to starch content. Plastids in columella cells of normal and mutant seedlings were associated with bands of microtubule-like structures, suggesting that these structures may be involved in 'positioning' plastids in the cell.

  20. Photosynthesis and transpiration of loblolly pine seedlings as influenced by moisture-stress conditioning

    SciTech Connect

    Seiler, J.R.; Johnson, J.D.

    1985-01-01

    One-yr-old seedlings were exposed to 8 wk of moisture stress conditioning (MSC); seedlings were watered only when pre-dawn needle water potential fell below -1.4 MPa. Water was then withheld and photosynthesis and transpiration rates recorded. Photosynthesis in well-watered controls and MSC seedlings was reduced to zero in 12 and 17 days respectively. Seedlings were harvested and water use efficiency calculated using photosynthesis and transpiration data; it was expressed as mg of CO/sub 2/ fixed per g of water lost. Seedlings exposed to MSC continued to photosynthesize to much lower needle water potentials. This response is at least partly attributed to the significant decrease (0.45 MPa) in needle osmotic potential found in MSC seedlings, which were able to maintain turgor to lower needle water potentials. Transpiration rate decreased 30% and water use efficiency increased 67% as a result of MSC. 26 references.

  1. Growth response of Pinus densiflora seedlings inoculated with three indigenous ectomycorrhizal fungi in combination

    PubMed Central

    Dalong, M.; Luhe, W.; Guoting, Y.; Liqiang, M.; Chun, L.

    2011-01-01

    Pinus densiflora seedlings were inoculated with three indigenous ectomycorrhizal fungi (Cenococcum geophilum, Rhizopogon roseolus and Russula densifolia) in single-, two-, and three-species treatments. After 8 months, the colonization rates of each ectomycorrhizal species, seedling growth and the nutrition were assessed in each treatment. P. densiflora seedlings inoculated with different ECM species composition showed an increase in height and basal diameter and improved seedling root and shoot nutrition concentrations compared to control treatment. Generally, combined inoculation had a more positive influence on the seedlings than the single inoculation. The three-species inoculation presented the highest growth and basal diameter and concentration of most nutrients except potassium. In conclusion, the results provided strong evidence for benefits of combined inoculation with the indigenous ectomycorrhizal fungi on P. densiflora seedlings under controlled conditions. PMID:24031742

  2. Growth response of Pinus densiflora seedlings inoculated with three indigenous ectomycorrhizal fungi in combination.

    PubMed

    Dalong, M; Luhe, W; Guoting, Y; Liqiang, M; Chun, L

    2011-07-01

    Pinus densiflora seedlings were inoculated with three indigenous ectomycorrhizal fungi (Cenococcum geophilum, Rhizopogon roseolus and Russula densifolia) in single-, two-, and three-species treatments. After 8 months, the colonization rates of each ectomycorrhizal species, seedling growth and the nutrition were assessed in each treatment. P. densiflora seedlings inoculated with different ECM species composition showed an increase in height and basal diameter and improved seedling root and shoot nutrition concentrations compared to control treatment. Generally, combined inoculation had a more positive influence on the seedlings than the single inoculation. The three-species inoculation presented the highest growth and basal diameter and concentration of most nutrients except potassium. In conclusion, the results provided strong evidence for benefits of combined inoculation with the indigenous ectomycorrhizal fungi on P. densiflora seedlings under controlled conditions. PMID:24031742

  3. Survival of planted tupelo seedlings in F- and H-Area tree-kill zones

    SciTech Connect

    Nelson, E.A.; Rogers, V.A.

    1995-01-01

    Swamp tupelo seedlings were planted in four areas which experienced previous tree mortality at the seeplines of the F- and H-Area Seepage Basins. The sites represented a range in severity of impact and stage of recovery. Seedlings were planted in February of 1994 and followed through the first growing season in the field. Survival on all sites through the first growing season was excellent, with greater than 92% of the seedlings still alive. Most seedlings appeared healthy with few external signs of stress. The performance of the seedlings will be followed in subsequent years to determine the physical state of the soil environment on seedling growth. Hopefully, the results will indicate that artificial reforestation can begin on similarly impacted sites prior to the beginning of natural revegetation of the site.

  4. Controlling herbaceous competition in pasture planted with loblolly pine seedlings. Forest Service research note

    SciTech Connect

    Haywood, J.D.

    1995-09-01

    Three treatments designed to control herbaceous vegetation competing with loblolly pine (Pinus taeda L.) seedlings planted in grazed and ungrazed pasture were tested. Effects of the treatments on seedling survival and growth during the first 3 years after planting were determined. The treatments were directed application of herbicides (glyphosate in the first 2 years and hexazinone in the third year), rotary mowing, and mulching with pine straw around individual pine seedlings.

  5. Absorption and assimilation of nitrate and ammonium ions by jack pine seedlings.

    PubMed

    Lavoie, N; Vzina, L P; Margolis, H A

    1992-09-01

    Jack pine (Pinus banksiana Lamb.) seedlings were grown in a shaded or unshaded light regime with either NO(3) (-)- or NH(4) (+)-N as the sole N source. After three months, seedlings grown with NH(4) (+)-N were larger than seedlings grown with NO(3) (-)-N. Irradiance had a greater effect on growth of ammonium-fed seedlings than on growth of nitrate-fed seedlings.At all times from 6 to 24 h following incorporation of (15)N, soluble, insoluble, and total (15)N contents of shoots and roots were higher in ammonium-fed seedlings than in nitrate-fed seedlings. The pattern of (15)N accumulation in shoots was similar to that in roots. After 6 and 24 h of (15)N incorporation, unshaded, ammonium-fed seedlings had 8.8 and 2.8 times greater total (15)N contents, respectively, than unshaded, nitrate-fed seedlings. In response to shading, ammonium-fed seedlings increased their total uptake of (15)N per unit root weight, whereas nitrate-fed seedlings did not. No nitrate or (15)NO(3) (-) was detected in any plant tissue. Nitrate-fed plants had higher NH(4) (+), Asp, and Gln concentrations in needles and higher gamma-aminobutyric acid and Arg concentrations in stems. Accumulation of (15)N in roots was not affected by the pH of the (15)N solution or by the N source fed to the seedlings before the period of (15)N incorporation. Thus NO(3) (-) transport into roots, rather than its reduction or transport within the plant, seems to be the factor limiting the growth of jack pine supplied with NO(3) (-)-N as the sole N source. PMID:14969960

  6. The importance of seed reserves for seedling performance: an integrated approach using morphological, physiological, and stable isotope techniques.

    PubMed

    Kennedy, P G; Hausmann, N J; Wenk, E H; Dawson, T E

    2004-12-01

    To investigate how seed reserves affect early seedling performance, we conducted a factorial greenhouse experiment using Lithocarpus densiflora (Tanoak). Seedlings were grown from large (5.8+/-0.7 g) and small (3.2+/-0.4 g) seeds and, following shoot emergence, seeds were either removed or left attached. Seedlings were harvested for quantification of biomass and delta13C at seven time periods following seed removal (2, 4, 8, 16, 32, 64, 128 days) and seedling photosynthesis was measured three separate time periods (2-4, 49-82, 95-128 days after seed removal). Biomass increased for all seedlings, but the increase was significantly larger for seedlings with attached seeds than with removed seeds. Seed removal just after shoot emergence significantly decreased seedling biomass, but seed removal 64 days after shoot emergence had no effect on seedling biomass. Seedling photosynthesis per unit leaf area varied by time and seed presence, but not by seed size. At the first period, seedlings with attached seeds had significantly higher photosynthetic rates than seedlings with removed seeds, at the second period there was no effect of seed removal, and at the third time period seedlings with attached seeds had significantly lower photosynthetic rates than seedlings with removed seeds. Despite temporal variation in photosynthesis per unit leaf area, seedlings with attached seeds always had significantly greater leaf area than seedlings with removed seeds, resulting in significantly higher total plant photosynthesis at all three time periods. The delta13C values of both the leaves and roots were more similar to that of the seed for seedlings with attached seeds than for seedlings with removed seeds, however, seed removal and seed size strongly affected root delta13C. This study demonstrates that seed reserves have important effects on the early growth, physiology, and delta13C of L. densiflora seedlings. PMID:15338415

  7. Community-Wide Spatial and Temporal Discordances of Seed-Seedling Shadows in a Tropical Rainforest

    PubMed Central

    Rother, Dbora Cristina; Pizo, Marco Aurlio; Siqueira, Tadeu; Rodrigues, Ricardo Ribeiro; Jordano, Pedro

    2015-01-01

    Several factors decrease plant survival throughout their lifecycles. Among them, seed dispersal limitation may play a major role by resulting in highly aggregated (contagious) seed and seedling distributions entailing increased mortality. The arrival of seeds, furthermore, may not match suitable environments for seed survival and, consequently, for seedling establishment. In this study, we investigated spatio-temporal patterns of seed and seedling distribution in contrasting microhabitats (bamboo and non-bamboo stands) from the Brazilian Atlantic Forest. Spatial distribution patterns, spatial concordance between seed rain and seedling recruitment between subsequent years in two fruiting seasons (20042005 and 20072009), and the relation between seeds and seedlings with environmental factors were examined within a spatially-explicit framework. Density and species richness of both seeds and seedlings were randomly distributed in non-bamboo stands, but showed significant clustering in bamboo stands. Seed and seedling distributions showed across-year inconsistency, suggesting a marked spatial decoupling of the seed and seedling stages. Generalized linear mixed effects models indicated that only seed density and seed species richness differed between stand types while accounting for variation in soil characteristics. Our analyses provide evidence of marked recruitment limitation as a result of the interplay between biotic and abiotic factors. Because bamboo stands promote heterogeneity in the forest, they are important components of the landscape. However, at high densities, bamboos may limit recruitment for the plant community by imposing marked discordances of seed arrival and early seedling recruitment. PMID:25856393

  8. Water stress can induce quiescence in newly-germinated onion (Allium cepa L.) seedlings.

    PubMed

    Whalley, W R; Lipiec, J; Finch-Savage, W E; Cope, R E; Clark, L J; Rowse, H R

    2001-05-01

    The effect of water stress on the early seedling growth of onions was studied by placing newly-germinated seedlings in vermiculite equilibrated at different water potentials. Roots and shoots elongated more at -0.29 than at -0.64 MPa, but did not elongate at -1.66 MPa. However, roots and shoots of seedlings that had been incubated in vermiculite at -1.66 MPa for up to 35 d resumed elongation when subsequently placed on wet filter boards. This suggests that water stress can induce quiescence in newly-germinated seedlings. PMID:11432930

  9. Grazing on regeneration sites encourages pine seedling growth. Forest Service research paper (Final)

    SciTech Connect

    Ratliff, R.D.; Denton, R.G.

    1995-12-31

    Effects of season-long, deferred-rotation, and rest-rotation grazing, on ponderosa pine (Pinus ponderosa Dougl. ex Laws.) seedling growth and herbaceous vegetation control were studied in regeneration sites at Boyd Hill, Modoc National Forest, California. Seedlings were planted in 1989. Pine seedling survival and damage did not differ, but the seedlings were significantly taller, with longer leaders with season-long grazing than without grazing. Treatment comparisons for plant group and non-plant percent cover differed only for litter and bare soil, but cover and composition of bottlebrush squirreltail (Elymus elymoides (Raf.) Swezey) were greater without grazing.

  10. Synthesis of ectomycorrhizae on northern red oak seedlings in a Michigan nursery

    SciTech Connect

    Dixon, R.K.; Johnson, P.S.

    1993-01-01

    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 nutrition. At the end of year one, treated seedlings were successfully inoculated with S. luteus, but the percentage varied significantly with family. Suillus luteus persisted on lateral roots two years following sowing. Two of four seedling families inoculated with S. luteus were significantly larger in size than control plants. These results suggest that the fungal symbiont S. luteus can be successfully introduced into nurseries and that early ectomycorrhizal development improves the growth of northern red oak seedlings.

  11. Treatment with 24-epibrassinolide, a brassinosteroid, increases the basic thermotolerance of Brassica napus and tomato seedlings.

    PubMed

    Dhaubhadel, S; Chaudhary, S; Dobinson, K F; Krishna, P

    1999-05-01

    Brassinosteroids are plant growth-promoting compounds that exhibit structural similarities to animal steroid hormones. Recent studies have indicated that brassinosteroids are essential for proper plant development. In addition to a role in development, several lines of evidence suggest that brassinosteroids exert anti-stress effects on plants. However, the mechanism by which they modulate plant stress responses is not understood. We show here that Brassica napus and tomato seedlings grown in the presence of 24-epibrassinolide (EBR) are significantly more tolerant to a lethal heat treatment than are control seedlings grown in the absence of the compound. Since a preconditioning treatment of seedlings was not required to observe this effect, we conclude that EBR treatment increases the basic thermotolerance of seedlings. An analysis of heat shock proteins (HSPs) in B. napus seedlings by western blot analysis indicated that the HSPs did not preferentially accumulate in EBR-treated seedlings at the control temperature. However, after heat stress, HSP accumulation was higher in EBR-treated than in untreated seedlings. The results of the present study provide the first direct evidence for EBR-induced expression of HSPs. The higher accumulation of HSPs in EBR-treated seedlings raises the possibility that HSPs contribute, at least in part, to thermotolerance in EBR-treated seedlings. A search for factors other than HSPs, which may directly or indirectly contribute to brassinosteroid-mediated increase in thermotolerance, is underway. PMID:10412911

  12. Community-wide spatial and temporal discordances of seed-seedling shadows in a tropical rainforest.

    PubMed

    Rother, Dbora Cristina; Pizo, Marco Aurlio; Siqueira, Tadeu; Rodrigues, Ricardo Ribeiro; Jordano, Pedro

    2015-01-01

    Several factors decrease plant survival throughout their lifecycles. Among them, seed dispersal limitation may play a major role by resulting in highly aggregated (contagious) seed and seedling distributions entailing increased mortality. The arrival of seeds, furthermore, may not match suitable environments for seed survival and, consequently, for seedling establishment. In this study, we investigated spatio-temporal patterns of seed and seedling distribution in contrasting microhabitats (bamboo and non-bamboo stands) from the Brazilian Atlantic Forest. Spatial distribution patterns, spatial concordance between seed rain and seedling recruitment between subsequent years in two fruiting seasons (2004-2005 and 2007-2009), and the relation between seeds and seedlings with environmental factors were examined within a spatially-explicit framework. Density and species richness of both seeds and seedlings were randomly distributed in non-bamboo stands, but showed significant clustering in bamboo stands. Seed and seedling distributions showed across-year inconsistency, suggesting a marked spatial decoupling of the seed and seedling stages. Generalized linear mixed effects models indicated that only seed density and seed species richness differed between stand types while accounting for variation in soil characteristics. Our analyses provide evidence of marked recruitment limitation as a result of the interplay between biotic and abiotic factors. Because bamboo stands promote heterogeneity in the forest, they are important components of the landscape. However, at high densities, bamboos may limit recruitment for the plant community by imposing marked discordances of seed arrival and early seedling recruitment. PMID:25856393

  13. Seasonal Pattern of Tomato Mosaic Tobamovirus Infection and Concentration in Red Spruce Seedlings

    PubMed Central

    Bachand, George D.; Castello, John D.

    1998-01-01

    Tomato mosaic tobamovirus (ToMV) infects red spruce (Picea rubens) and causes significant changes in its growth and physiology. The mechanism of infection and the pattern of virus concentration in seedling roots and needles were investigated. One-year-old red spruce seedlings were obtained from the nursery in April and June 1995 and August 1996 and tested for ToMV using enzyme-linked immunosorbent assay (ELISA). Virus-free seedlings were divided into three treatments: control, root inoculated, and needle inoculated. Two control, five root-inoculated, and five needle-inoculated seedlings were sampled destructively at biweekly intervals for 3 months and then tested for ToMV by ELISA. ToMV was transmitted to seedlings by root but not by needle inoculation. The virus was detected in 67 to 100% of roots but in less than 7% of needles of root-inoculated seedlings. The percent infection of root-inoculated seedlings differed significantly between the April and June and between the April and August inoculation periods. Virus concentration in infected seedling roots increased initially, peaked within 4 weeks postinoculation, and steadily declined thereafter. Significant differences in ToMV concentrations in roots also were detected among inoculation periods and sampling dates. Early spring may represent the optimal time for infection of seedlings, as well as for assaying roots for ToMV. PMID:16349546

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

    NASA Technical Reports Server (NTRS)

    1982-01-01

    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).

  15. Improving seedling growth in longleaf pine plantations with nematicidal soil fumigants.

    PubMed

    Ruehle, J L

    1969-07-01

    In-row, preplanting fumigation with DD and DBCP in a longleaf pine plantation was evaluated for nematode control, improved seedling survival, and early and uniform release of seedlings from the grass stage. Only DD significantly lowered the nematode population during the first growing season. DBCP not only failed to control nematodes, but was phytotoxic. Fumigation had little effect on seedling survival. Seedlings in rows fumigated with DD started height growth earlier and produced taller trees after 5 years than those in nonfumigated rows. PMID:19325685

  16. Differences in vole preference, secondary chemistry and nutrient levels between naturally regenerated and planted Norway spruce seedlings.

    PubMed

    Virjamo, Virpi; Julkunen-Tiitto, Riitta; Henttonen, Heikki; Hiltunen, Eveliina; Karjalainen, Reijo; Korhonen, Juhani; Huitu, Otso

    2013-10-01

    Field voles (Microtus agrestis) cause severe damage to young Norway spruce (Picea abies) plantations during wintertime in Fennoscandia. We experimentally investigated vole preference for winter-dormant, naturally regenerated seedlings; spring-planted seedlings; or autumn-planted seedlings; and how preference corresponds with seedling chemistry. Voles showed the highest preference for autumn-planted seedlings and the second highest for spring-planted seedlings, while naturally regenerated seedlings were avoided. The stems of the autumn-planted seedlings contained higher concentrations of nitrogen and piperidine alkaloids and lower concentrations of stilbenes than did the other groups. In addition to differences between naturally regenerated and planted seedlings, we investigated seasonal differences in naturally regenerated P. abies needle and bark secondary chemistry. While piperidine alkaloid concentrations did not vary with season, the soluble non-tannin phenolics of needles and the condensed tannins of bark were lower in May than in November or January. At the time of planting, the concentration of bark piperidine alkaloids was higher in autumn-planted than in spring-planted seedlings. We detected two alkaloids not previously found in P. abies, 2-methyl-6-propyl-1,6-piperideine and a tentatively identified pinidine-isomer. Our results demonstrate that vole choice of spruce seedlings is promoted by high nitrogen and low stilbene content, both associated with seedlings planted late in the season. As vole damage is linked to seedling chemistry, damage potentially could be mitigated by advancing planting or by manipulating plant chemistry in nurseries. PMID:24105602

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

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

    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.

  18. Role of Catalase in Inducing Chilling Tolerance in Pre-Emergent Maize Seedlings.

    PubMed Central

    Prasad, T. K.

    1997-01-01

    The mechanisms of chilling acclimation and the role of antioxidant enzymes, catalase in particular, in inducing chilling tolerance in pre-emergent maize (Zea mays L.) seedlings have been investigated. Seedlings were acclimated to chilling stress in two different ways. Three-day-old seedlings did not survive 7 d of 4[deg]C stress unless acclimated by exposure to either 14[deg]C for 1 d or 4[deg]C for 1 d followed by recovery at 27[deg]C for 1 d. Although no changes in superoxide dismutase and ascorbate peroxidase activities were observed, both kinds of acclimated seedlings had higher catalase (CAT), glutathione reductase, and guaiacol peroxidase activities compared with nonacclimated seedlings during low-temperature stress and recovery conditions. To study the role of CAT in chilling tolerance, aminotriazole (AT) was used as a tool to artificially inhibit CAT activity and to initiate oxidative stress in the seedlings. Treatment of acclimating seedlings with 3 mM AT for 18 h abolished the acclimation phenomenon. AT treatment was found to be specific to CAT inhibition, because the total activities or isozyme profiles of the other investigated antioxidant enzymes were not altered in AT-treated seedlings. Protein carbonyl content, an indication of oxidative damage, was increased 2-fold in nonacclimated and AT-treated acclimated seedlings. These results collectively indicate that acclimation to prolonged chilling stress can be achieved by briefly pre-exposing the seedlings to 4[deg]C chilling stress and that acclimation-induced (oxidative stress-induced) CAT seems to play a major role, probably along with other antioxidant enzymes, in inducing chilling tolerance in pre-emergent maize seedlings. PMID:12223775

  19. [Effect of ectomycorrhizal fungi on the seedlings growth of Korea spruce].

    PubMed

    Song, Rui-Qing; Wang, Feng; Ji, Rui-Qing; Qi, Jin-Yu

    2007-12-01

    To enhance the effects of ectomycorrhizal fungi to promote the growth of Korea spruce seedlings, based on previous research, the combinations of different ectomycorrhizal fungi strains were screened by dual culture method. 3 years transplanting seedlings of Korea spruce were inoculated by different combinations of ectomycorrhizal fungi strains using lister inoculating method in the field, and those were inoculated by different single strains were designed as control respectively. Thus the effects of different combinations and different single fungus strains to promote the growth of Korea spruces were studied. The results showed that all single strains and combinations in this experiment can promote the growth of Korea spruce seedlings. The growth characteristics of seedlings were observed 100 days after inoculation. The growth promoting effect of strain L15 was the best in all combinations and single strains. Comparing with control, the average height of seedlings inoculated by strain L15 was increased 30.88%, the average collar diameter of these was increased 15.29%. The growth promoting effect of combinations L15/025 or L15/009 were better than strain 009 or 025. Comparing with control, the leaf chlorophyll contents of seedling inoculated by strain 010 and combination L15/025 were increased significantly, the contents of chlorophyll a were increased 59.15% and 54.61% respectively, and the contents of chlorophyll b were increased 76.34% and 67.78% respectively. Except seedling inoculated by strain 010, the activities of hydrogen peroxidase of other treated seedlings were lower than one of control. The root activities of all treated seedlings were lower than one of control. In conclusion, inoculation by the mixture of high-effect strain and other single strain weakens the effect of high-effect strain to promote the growth of Korea spruce seedlings, the activity of hydrogen peroxidase and the root activity of seedling are not correlated with its biomass. PMID:18271271

  20. [Effects of sowing depth on seedling traits and root characteristics of summer maize].

    PubMed

    Cao, Hui-ying; Wang, Ding-bo; Shi, Jian-guo; Zhu, Kun-lun; Dong, Shu-ting; Liu, Peng; Zhao, Bin; Zhang, Ji-wang

    2015-08-01

    Two summer maize hybrids, Zhengdan 958 (ZD958) and Xianyu 335 (XY335), were used as experimental materials. 4 sowing depths (3, 5, 7 and 9 cm) and uneven sowing depth (CK) were designed under sand culture and field experiments to investigate the effects of sowing depth on seedling traits and root characteristics of summer maize. The results showed that the seedling emergence rate gradually decreased and seedling emergence time gradually lengthened as the sowing depth increased. Compared with the sowing depth of 3 cm, the seedling emergence rates of ZD958 and XY335 sown at the depth of 9 cm were reduced by 9.4% and 11.8%, respectively, and the seedling emergence duration was prolonged 1.5 d. With the increasing sowing depth, the seedling length and uniformity decreased significantly, the mesocotyl length increased significantly, while the coleoptile length had no significant difference; the primary radicle length gradually decreased, the total length of secondary radicle gradually increased, and the total root length had no significant difference; the total dry mass of seedling and mesocotyl increased significantly, and the total root dry mass had no significant difference. With the increasing sowing depth, the soluble sugar content in each part of seedling increased and the amount of nutritional consumption of germinating seeds increased, the seedling root growth rate increased, but the root activity decreased, and the number of total nodal root and nodal layers increased. With the increasing sowing depth, harvested ears per unit area were reduced by decreased seedling emergence rate and seedling vigor, thus influenced the yield. In addition, uniform sowing depth could improve the canopy uniformity and relative characteristics, then increase the yield. PMID:26685603

  1. Following isotopes in pulse-chase enriched aspen seedlings

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    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.

  2. Proteomic responses in Arabidopsis thaliana seedlings treated with ethylene.

    PubMed

    Chen, Ruiqiang; Binder, Brad M; Garrett, Wesley M; Tucker, Mark L; Chang, Caren; Cooper, Bret

    2011-09-01

    Ethylene (ET) is a volatile hormone that modulates fruit ripening, plant growth, development and stress responses. Key components of the ET-signaling pathway identified by genetic dissection in Arabidopsis thaliana include five ET receptors, the negative regulator CTR1 and the positive regulator EIN2, all of which localize to the endoplasmic reticulum. Mechanisms of signaling among these proteins are still unresolved and targets of ET responses are not fully known. So, we used mass spectrometry to identify proteins in microsomal membrane preparations from etiolated A. thaliana seedlings maintained in ambient air or treated with ET for 3 h. We compared 3814 proteins from ET-exposed seedlings and controls and identified 304 proteins with significant accumulation changes. The proteins with increased accumulation were involved in ET biosynthesis, cell morphogenesis, oxidative stress and vesicle secretion while those with decreased accumulation were ribosomal proteins and proteins positively regulated by brassinosteroid, another hormone involved in cell elongation. Several proteins, including EIN2, appeared to be differentially phosphorylated upon ET treatment, which suggests that the activity or stability of these proteins may be controlled by phosphorylation. TUA3, a component of microtubules that contributes to cellular morphological change, exhibited both increased accumulation and differential phosphorylation upon ET treatment. To verify the role of TUA3 in the ET response, tua3 mutants were evaluated. Mutant seedlings had altered ET-associated growth movements. The data indicate that ET perception leads to rapid proteomic change and that these changes are an important part of signaling and development. The data serve as a foundation for exploring ET signaling through systems biology. PMID:21713283

  3. Oxidation of Spermine by an Amine Oxidase from Lentil Seedlings

    PubMed Central

    Cogoni, Antonina; Padiglia, Alessandra; Medda, Rosaria; Segni, Paolo; Floris, Giovanni

    1991-01-01

    Spermine is a substrate of lentil (Lens culinaris) seedling amine oxidase and the oxidation products are reversible inactivators of the enzyme. The spermine is oxidized at the terminal amino groups to a dialdehyde: 2 moles of hydrogen peroxide and 2 moles of ammonia per mole of spermine are formed. The pH optimum of the enzyme with spermine is 7.9 in TI-HCI buffer; the Km value is 4.4·10−4 molar, similar to that found with other substrates (putrescine and spermidine). PMID:16668008

  4. Enhancing seedling production of native species to restore gypsum habitats.

    PubMed

    Caadas, E M; Ballesteros, M; Foronda, A; Navarro, F B; Jimnez, M N; Lorite, J

    2015-11-01

    Gypsum habitats are widespread globally and are important for biological conservation. Nevertheless, they are often affected by human disturbances and thus require restoration. Sowing and planting have shown positive results, but these actions are usually limited by the lack of native plant material in commercial nurseries, and very little information is available on the propagation of these species. We address this issue from the hypothesis that gypsum added to a standard nursery growing medium (peat) can improve seedling performance of gypsum species and, therefore, optimise the seedling production for outplanting purposes. We test the effect of gypsum on emergence, survival, and growth of nine native plant species, including gypsophiles (exclusive to gypsum) and gypsovags (non-exclusive to gypsum). We used four treatments according to the proportions, in weight, of gypsum:standard peat (G:S), i.e. high-g (50G:50S), medium-g (25G:75S), low-g (10G:90S), and standard-p (0G:100S). Our results showed that the gypsum treatments especially benefited the emergence stage, gypsophiles as group, and Ononis tridentata as a taxon. In particular, the gypsum treatments enhanced emergence of seven species, survival of three species, and growth of two gypsophiles, while the use of the standard peat favoured only the emergence or growth of three gypsovags. Improving emergence and survival at the nursery can provide a reduction of costs associated with seed harvesting, watering, and space, while enlarging seedlings can favour the establishment of individuals after outplanting. Thus, we suggest adding gypsum to standard peat for propagating seedlings in species from gypsum habitats, thereby potentially cutting the costs of restoring such habitats. Our assessment enables us to provide particular advice by species. In general, we recommend using between 25 and 50% of gypsum to propagate gypsophiles, and between 0 and 10% for gypsovags. The results can benefit not only the production of widely distributed species commonly affected by gypsum quarrying, but also of narrow and threatened endemic species that require particularly efficient use of their seeds. In addition, our study highlights the importance of using appropriate growing media to propagate plants characteristic of special substrates for restoration purposes. PMID:26301687

  5. Endogenous Rhythmicity of Ethylene Production in Growing Intact Cereal Seedlings 1

    PubMed Central

    Ievinsh, Gederts; Kreicbergs, Olgerts

    1992-01-01

    Ethylene evolution from etiolated barley (Hordeum vulgare), wheat (Triticum aestivum), and rye (Secale cereale) seedlings during coleoptile growth followed a rhythmic pattern, with a period of about 16 h for barley and wheat and 12 h for rye seedlings. Leaf emergence disturbed the established rhythm of ethylene evolution. PMID:16653134

  6. Germination, survival, and growth of grass and forb seedlings: effects of soil moisture variability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed germination and seedling growth, survivorship, and final biomass and their responses to varying numbers of days between watering were studied in two grass and six forb species native to the U.S. Central Plains grasslands. Our object was to assess the potential role of germination and seedling g...

  7. Environmental factors and seed abundance influence seedling emergence of a perennial forest herb

    NASA Astrophysics Data System (ADS)

    Kolb, Annette; Barsch, Katharina

    2010-09-01

    Seedlings are an important, but vulnerable stage in the life cycle of plants. The identification of factors affecting their recruitment is therefore fundamental for understanding basic plant population processes as well as plant distribution and abundance. In this study, we used a combined experimental and observational approach to examine how microsite quality and quantity as well as seed supply affect different processes of seedling establishment, using the perennial forest herb Phyteuma spicatum (Campanulaceae) as model species. This species reproduces exclusively by seed, and seedling emergence, growth and survival are therefore critical stages in its life cycle. Seedlings were frequent in microsites with bare soil and overall high light intensities, and were less common in sites with deep litter layers as well as dense and low vegetation. Seed addition, via experimental sowings or via the natural seed rain, consistently enhanced seedling emergence. Seed density effects, however, were variable among years; seedling emergence rates decreased at high seed densities in one of two seed cohorts. Seedling emergence time, size and survival were largely not affected by microhabitat type or seed density. In summary, our findings suggest that environmental factors and seed abundance determine recruitment success of P. spicatum and that effects on early processes of seedling establishment (emergence) are stronger than effects on late processes of establishment (growth and survival). Our work thereby contributes to a better understanding of the mechanisms underlying recruitment patterns of this species and other perennial herbs.

  8. ANATOMY OF THE SEED AND SEEDLING OF SPARTINA ALTERNIFLORA LOIS (POACEAE)

    EPA Science Inventory

    Members of the genus Spartina are dominant macrophytes in many salt marshes of North and South America, Europe, and Africa. Although the genus is of great ecological importance, seeds and seedlings of its 16 species have not been described. he seed and seedling of an American spe...

  9. Limited evolutionary divergence of seedlings after the domestication of plant species.

    PubMed

    Milla, R; Morente-Lpez, J

    2015-01-01

    The most vulnerable stage in the life of plants is the seedling. The transition from wild to agricultural land that plants experienced during and after domestication implied a noticeable change in the seedlings' environment. Building on current knowledge of seedling ecology, and on previous studies of cassava, we hypothesise that cultivation should have promoted epigeal germination of seedlings, and more exposed and photosynthetic cotyledons. To test this hypothesis, we phenotyped seedling morpho-functional traits in a set of domesticated and wild progenitor accessions of 20 Eudicot herbaceous crop species. Qualitative traits like epi- versus hypogeal germination, leafy versus storage type of cotyledons, or crypto- versus phanerocotyledonar germination, remained conserved during the domestication of all 20 species. Lengths of hypocotyls and epicotyls, of cotyledon petioles, and indices of cotyledon exposure to the aboveground environment changed during evolution under cultivation. However, those changes occurred in diverse directions, depending on the crop species. No common seedling phenotypic convergence in response to domestication was thus detected among the group of species studied here. Also, none of the 20 crops evolved in accordance with our initial hypothesis. Our results reject the idea that strong selective filters exerted unconsciously by artificial selection should have resulted in generalised channelling of seedling morphology towards more productive and more herbivore risky phenotypes. This result opens up unexplored opportunities for directional breeding of seedling traits. PMID:24943713

  10. Negative Associations Between Seedlings and Adult Plants In Two Alpine Plant Communities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant species requirements at seed and seedling stages are critical in determining their distributions. Proximity to adult plants, as well as the presence of litter or rocks on the soil surface can influence seedling success. By comparing the microsite characteristics of points occupied by naturall...

  11. Seed and seedling ecology research as the foundation for enhancing restoration outcomes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The success of restoration in arid and semiarid rangelands is severely limited by deficiencies in our understanding of seedling ecology and seedling recruitment. This is significant because rangelands provide sustenance for roughly one-third of the global population, and evolving challenges such as...

  12. CROWN GALL INCIDENCE: SEEDLING PARADOX WALNUT ROOTSTOCK VERSUS OWN-ROOTED ENGLISH WALNUT TREES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seedling Paradox (Juglans hindsii x J. regia) has been the rootstock of choice for English walnut in California because of its vigor and greater tolerance of wet soil conditions. However, seedling Paradox rootstock is highly susceptible to crown gall, a disease caused by the soil-borne bacterium Agr...

  13. Phosphorus limits Eucalyptus grandis seedling growth in an unburnt rain forest soil

    PubMed Central

    Tng, David Y. P.; Janos, David P.; Jordan, Gregory J.; Weber, Ellen; Bowman, David M. J. S.

    2014-01-01

    Although rain forest is characterized as pyrophobic, pyrophilic giant eucalypts grow as rain forest emergents in both temperate and tropical Australia. In temperate Australia, such eucalypts depend on extensive, infrequent fires to produce conditions suitable for seedling growth. Little is known, however, about constraints on seedlings of tropical giant eucalypts. We tested whether seedlings of Eucalyptus grandis experience edaphic constraints similar to their temperate counterparts. We hypothesized that phosphorous addition would alleviate edaphic constraints. We grew seedlings in a factorial experiment combining fumigation (to simulate nutrient release and soil pasteurization by fire), soil type (E. grandis forest versus rain forest soil) and phosphorus addition as factors. We found that phosphorus was the principal factor limiting E. grandis seedling survival and growth in rain forest soil, and that fumigation enhanced survival of seedlings in both E. grandis forest and rain forest soil. We conclude that similar to edaphic constraints on temperate giant eucalypts, mineral nutrient and biotic attributes of a tropical rain forest soil may hamper E. grandis seedling establishment. In rain forest soil, E. grandis seedlings benefited from conditions akin to a fire-generated ashbed (i.e., an ashbed effect). PMID:25339968

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

    SciTech Connect

    Foote, K.R.

    1980-03-01

    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.

  15. Effect of Continuous Cropping Generations on Each Component Biomass of Poplar Seedlings during Different Growth Periods

    PubMed Central

    Xia, Jiangbao; Zhang, Shuyong; Li, Tian; Liu, Xia; Zhang, Ronghua; Zhang, Guangcan

    2014-01-01

    In order to investigate the change rules and response characteristics of growth status on each component of poplar seedling followed by continuous cropping generations and growth period, we clear the biomass distribution pattern of poplar seedling, adapt continuous cropping, and provide theoretical foundation and technical reference on cultivation management of poplar seedling, the first generation, second generation, and third generation continuous cropping poplar seedlings were taken as study objects, and the whole poplar seedling was harvested to measure and analyze the change of each component biomass on different growth period poplar leaves, newly emerging branches, trunks and root system, and so forth. The results showed that the whole biomass of poplar seedling decreased significantly with the leaf area and its ratio increased, and the growth was inhibited obviously. The biomass aboveground was more than that underground. The ratios of leaf biomass and newly emerging branches biomass of first continuous cropping poplar seedling were relatively high. With the continuous cropping generations and growth cycle increasing, poplar seedling had a growth strategy to improve the ratio of root-shoot and root-leaf to adapt the limited soil nutrient of continuous cropping. PMID:25401150

  16. Wheat Seedlings as Food Supplement to Combat Free Radicals: An In Vitro Approach.

    PubMed

    Ravikumar, P; Shalini, G; Jeyam, M

    2015-01-01

    The present study was designed to evaluate the antioxidant activity of 5 organic solvent extracts (petroleum ether, n-hexane, chloroform, ethyl acetate and methanol) of wheat grains, 3, 5 and 7 days old wheat seedlings. To determine the antioxidant activity of five extracts of four different samples, 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity, total phenolic content and ferrous reducing power ability were carried out. 1,1-Diphenyl-2-picrylhydrazyl radical scavenging effect of chloroform and ethyl acetate extracts of 3 days old wheat seedlings was higher than wheat grains. Chloroform, ethyl acetate and methanol extracts of 3 days old wheat seedlings exhibited higher 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging effcet than extracts of other samples. The phenolic content was high in chloroform, ethyl acetate and methanol extract of 5 days old wheat seedlings. When compared with wheat grain, reducing power ability was high in chloroform, ethyl acetate and methanol extract of wheat seedlings, especially in 3 and 5 days old wheat seedlings. From the above results, it was concluded that chloroform, ethyl acetate and methanol extract of 3, 5 and 7 days old wheat seedlings showed better antioxidant activity than the wheat grain extracts. Hence, the results of the present study suggest the intake of wheat seedlings as a food supplement to combat the diseases caused by free radicals. PMID:26798175

  17. Effects of seed-caching desert rodents on seedling survival of Indian ricegrass (Achnatherum hymenoides)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In addition to consuming seeds, many small mammals also cache seeds in shallowly buried scatterhoards, and seeds of many plant species germinate and establish aggregated clusters of seedlings from these caches. Scatterhoards made by desert heteromyid rodents provide the primary source of seedling re...

  18. Wheat Seedlings as Food Supplement to Combat Free Radicals: An In Vitro Approach

    PubMed Central

    Ravikumar, P.; Shalini, G.; Jeyam, M.

    2015-01-01

    The present study was designed to evaluate the antioxidant activity of 5 organic solvent extracts (petroleum ether, n-hexane, chloroform, ethyl acetate and methanol) of wheat grains, 3, 5 and 7 days old wheat seedlings. To determine the antioxidant activity of five extracts of four different samples, 1,1-diphenyl-2-picrylhydrazyl and 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity, total phenolic content and ferrous reducing power ability were carried out. 1,1-Diphenyl-2-picrylhydrazyl radical scavenging effect of chloroform and ethyl acetate extracts of 3 days old wheat seedlings was higher than wheat grains. Chloroform, ethyl acetate and methanol extracts of 3 days old wheat seedlings exhibited higher 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging effcet than extracts of other samples. The phenolic content was high in chloroform, ethyl acetate and methanol extract of 5 days old wheat seedlings. When compared with wheat grain, reducing power ability was high in chloroform, ethyl acetate and methanol extract of wheat seedlings, especially in 3 and 5 days old wheat seedlings. From the above results, it was concluded that chloroform, ethyl acetate and methanol extract of 3, 5 and 7 days old wheat seedlings showed better antioxidant activity than the wheat grain extracts. Hence, the results of the present study suggest the intake of wheat seedlings as a food supplement to combat the diseases caused by free radicals. PMID:26798175

  19. Comparative transcription profiling analyses of maize reveals candidate defensive genes for seedling resistance against corn earworm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As maize seedlings germinate into the soil, they encounter an environment teaming with insects seeking rich sources of nutrition. Maize presumably has developed a number of molecular mechanisms to ensure survival at the beginning of its life cycle. Bioassays indicated maize seedlings were more toxic...

  20. Characterization of Rhizoctonia isolates associated with damping-off and crown rot of rooibos seedlings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia species were reported to be an important component of the complex involved in damping-off of rooibos (Aspalathus linearis) seedlings and cause severe crown rot of seedlings in nurseries. However, no information is available on the anastomosis groups (AGs) of Rhizoctonia associated with d...

  1. Determining Critical Phosphorus Levels for Cool Season Seedlings Established on Calcareous Soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sufficient soil phosphorus (P) is critical for rapid seedling establishment. P-deficient seedlings lack vigor and form low density turf areas which are more susceptible to soil erosion and nutrient loss. A greenhouse study was conducted to determine the critical soil P-levels necessary to establish ...

  2. Effect of sorghum seedlings of different genotypes, and previous crop, on soil microorganism populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hypotheses that sorghum seedlings of different genotypes will differentially modify soil microorganisms and will affect subsequently planted wheat seedlings were tested. Wheat cultivar Lewjain, and sorghum genotypes Redlan and RTx433 were planted into soils previously planted with wheat or sorghum. ...

  3. Maize white seedling 3 results from disruption of homogentisate solanesyl transferase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize white seedling 3 (w3) has served as a model albino-seedling mutant since its discovery in 1923. We show here that the w3 phenotype is caused by disruptions in homogentisate solanesyl transferase (HST), an enzyme that catalyzes the committed step in plastoquinone-9 (PQ9) biosynthesis. This re...

  4. FOLIAR N RESPONSE OF PONDEROSA PINE SEEDLINGS TO ELEVATED CO2 AND O3

    EPA Science Inventory

    Interactions between needle N status and exposure to combined CO2 and O3 stresses were studied in Pinus ponderosa seedlings. The seedlings were grown for three years (April 1998 through March 2001) in outdoor chambers in native soils from eastern Oregon, and exposed to ambient ...

  5. [Effects of grafting on root polyamine metabolism of cucumber seedlings under copper stress].

    PubMed

    Zhang, Zi-Kun; Liu, Shi-Qi; Liu, Su-Hui; Zhang, Yu; Chen, Kun; Huang, Zhi-Jun

    2010-08-01

    By the method of hydroponic culture, and taking Cucurbita ficifolia B. as rootstock, this paper studied the effects of grafting on the root polyamine metabolism of cucumber seedlings under copper stress. The results showed that under copper stress, the root activities of cucumber seedlings were inhibited, and electrolyte leakage increased, with these changes being significantly lower for grafted than for ungrafted cucumber seedlings. In addition, the contents of free spermidine and spermine, and of conjugated and bound polyamines were significantly higher in grafted than in ungrafted seedling roots, while the free putrescine content and the ratio of free putrescine to polyamines were on the contrary. Comparing with those in ungrafted cucumber seedlings, the root arginine decarboxylase (ADC), ornithine decarboxylase (ODC), and S-adenosylmethionine decarboxylase (SAMDC) activities in grafted cucumber seedlings were higher, while the diamine oxidase and polyamine oxidase activities were significantly lower. All of these indicated that under copper stress, the synthesis of polyamine in grafted seedling roots was increased, while the degradation of polyamine was decreased, resulting in a higher accumulation of polyamine in the roots, and the increase of the tolerance of cucumber seedlings to copper stress. PMID:21043115

  6. Effects of resource availability on seedling recruitment in a fire-maintained savanna.

    PubMed

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

    2010-05-01

    The herbaceous ground cover of the longleaf pine ecosystem harbors the highest plant species richness in North America, with up to 50 species per square meter, but the mechanisms that regulate this diversity are not well understood. In this system, variability in seedling recruitment events may best explain the extremely high small-scale species richness and its relationship to soil moisture and system net primary productivity. To understand the potential mechanistic controls on species richness, we used a long-term resource manipulation study across a natural soil moisture gradient to assess environmental controls on seedling recruitment. We considered the availability of resources to be an indicator of seedling safe-site supply, and also manipulated seed availability to examine the relative importance of recruitment limitations on seedling diversity. We found that water availability regulated the number of species in the seedling community regardless of the underlying natural moisture gradient, and that this effect may result from differential responses of seedling guilds to resource availability. Water supply was more important than seed supply in determining seedling establishment, suggesting that appropriate sites for regeneration are a factor limiting seedling success. This is the first study that shows that the episodic supply of microsites for recruitment could influence species richness in the highly threatened and biodiverse longleaf pine savanna. PMID:19921271

  7. Discovery of a novel anticancer agent with both anti-topoisomerase I and II activities in hepatocellular carcinoma SK-Hep-1 cells in vitro and in vivo: Cinnamomum verum component 2-methoxycinnamaldehyde.

    PubMed

    Perng, Daw-Shyong; Tsai, Yu-Hsin; Cherng, Jonathan; Wang, Jeng-Shing; Chou, Kuo-Shen; Shih, Chia-Wen; Cherng, Jaw-Ming

    2016-01-01

    Cinnamomum verum is used to make the spice cinnamon and has been used as a traditional Chinese herbal medicine for various applications. We evaluated the anticancer effect of 2-methoxycinnamaldehyde (2-MCA), a constituent of the bark of the plant, and its underlying molecular biomarkers associated with carcinogenesis in human hepatocellular carcinoma SK-Hep-1 cell line. The results show that 2-MCA suppressed proliferation and induced apoptosis as indicated by mitochondrial membrane potential loss, activation of caspase-3 and caspase-9, increase in the DNA content in sub-G1, and morphological characteristics of apoptosis, including blebbing of plasma membrane, nuclear condensation, fragmentation, apoptotic body formation, and long comet tail. In addition, 2-MCA also induced lysosomal vacuolation with increased volume of acidic compartments, suppressions of nuclear transcription factors NF-?B, cyclooxygenase-2, prostaglandin E2 (PGE2), and both topoisomerase I and II activities in a dose-dependent manner. Further study reveals the growth-inhibitory effect of 2-MCA was also evident in a nude mice model. Taken together, the data suggest that the growth-inhibitory effect of 2-MCA against SK-Hep-1 cells is accompanied by downregulations of NF-?B-binding activity, inflammatory responses involving cyclooxygenase-2 and PGE2, and proliferative control involving apoptosis, both topoisomerase I and II activities, together with an upregulation of lysosomal vacuolation and volume of acidic compartments. Similar effects (including all of the above-mentioned effects) were found in other tested cell lines, including human hepatocellular carcinoma Hep 3B, lung adenocarcinoma A549, squamous cell carcinoma NCI-H520, colorectal adenocarcinoma COLO 205, and T-lymphoblastic MOLT-3 (results not shown). Our data suggest that 2-MCA could be a potential agent for anticancer therapy. PMID:26792981

  8. Discovery of a novel anticancer agent with both anti-topoisomerase I and II activities in hepatocellular carcinoma SK-Hep-1 cells in vitro and in vivo: Cinnamomum verum component 2-methoxycinnamaldehyde

    PubMed Central

    Perng, Daw-Shyong; Tsai, Yu-Hsin; Cherng, Jonathan; Wang, Jeng-Shing; Chou, Kuo-Shen; Shih, Chia-Wen; Cherng, Jaw-Ming

    2016-01-01

    Cinnamomum verum is used to make the spice cinnamon and has been used as a traditional Chinese herbal medicine for various applications. We evaluated the anticancer effect of 2-methoxycinnamaldehyde (2-MCA), a constituent of the bark of the plant, and its underlying molecular biomarkers associated with carcinogenesis in human hepatocellular carcinoma SK-Hep-1 cell line. The results show that 2-MCA suppressed proliferation and induced apoptosis as indicated by mitochondrial membrane potential loss, activation of caspase-3 and caspase-9, increase in the DNA content in sub-G1, and morphological characteristics of apoptosis, including blebbing of plasma membrane, nuclear condensation, fragmentation, apoptotic body formation, and long comet tail. In addition, 2-MCA also induced lysosomal vacuolation with increased volume of acidic compartments, suppressions of nuclear transcription factors NF-κB, cyclooxygenase-2, prostaglandin E2 (PGE2), and both topoisomerase I and II activities in a dose-dependent manner. Further study reveals the growth-inhibitory effect of 2-MCA was also evident in a nude mice model. Taken together, the data suggest that the growth-inhibitory effect of 2-MCA against SK-Hep-1 cells is accompanied by downregulations of NF-κB-binding activity, inflammatory responses involving cyclooxygenase-2 and PGE2, and proliferative control involving apoptosis, both topoisomerase I and II activities, together with an upregulation of lysosomal vacuolation and volume of acidic compartments. Similar effects (including all of the above-mentioned effects) were found in other tested cell lines, including human hepatocellular carcinoma Hep 3B, lung adenocarcinoma A549, squamous cell carcinoma NCI-H520, colorectal adenocarcinoma COLO 205, and T-lymphoblastic MOLT-3 (results not shown). Our data suggest that 2-MCA could be a potential agent for anticancer therapy. PMID:26792981

  9. Defoliation by pastoralists affects savanna tree seedling dynamics by limiting the facilitative role of canopy cover.

    PubMed

    Bufford, Jennifer L; Gaoue, Orou G

    2015-07-01

    Recurrent tree defoliation by pastoralists, akin to herbivory, can negatively affect plant reproduction and population dynamics. However, our understanding of the indirect role of defoliation in seedling recruitment and tree-grass dynamics in tropical savanna is limited. In West African savanna, Fulani pastoralists frequently defoliate several fodder tree species to feed livestock in the dry season. We investigated the direct and indirect effects of recurrent defoliation of African mahogany (Khaya senegalensis) by Fulani people on seedling (< 2 cm basal diameter) and sapling dynamics in West Africa using four years of demographic data on seedling and sapling density, growth, and survival, coupled with fruit production and microhabitat data over the same time period. Tree canopy cover facilitated seedlings but had negative effects on sapling growth possibly via intraspecific competition with adult plants. Interspecific competition with grasses strongly reduced seedling survival but had a weak effect on sapling growth. Fire reduced seedling survival and weakly reduced growth of seedlings and saplings, but did not affect sapling survival. These results indicate that the effect of fire on seedlings and saplings is distinct, a mechanism suitable for an episodic recruitment of seedlings into the sapling stage and consistent with predictions from the demographic bottleneck model. Defoliation affected seedling density and sapling growth through changes in canopy cover, but had no effect on seedling growth and sapling survival. In the moist region, sapling density was higher in sites with low-intensity defoliation, indicating that defoliation may strengthen the tree recruitment bottleneck. Our study suggests that large-scale defoliation can alter the facilitative role of nurse trees on seedling dynamics and tree-sapling competition. Given that tree defoliation by local people is a widespread activity throughout savanna-forest systems in West Africa, it has the potential to affect tree-grass coexistence. Incorporating the influence of large tree defoliation into existing models of savanna dynamics can further our understanding of tree-grass coexistence and improve management. A rotating harvest system, which allows seedlings to recruit episodically, or a patchwork harvest, which maintains some nursery trees in the mosaic, could help sustain seedling recruitment and minimize the indirect effects of harvest. PMID:26485958

  10. Effects of tropospheric ozone on loblolly pine seedlings inoculated with root infecting ophiostomatoid fungi.

    PubMed

    Chieppa, Jeff; Chappelka, Art; Eckhardt, Lori

    2015-12-01

    Seedlings from four loblolly pine (Pinus taeda L.) families were exposed in open-top chambers to charcoal-filtered air (CF), non-filtered air (NF) or air amended with ozone to 2 times ambient (2). Two of the families used were selected for their tolerance to fungi associated with Southern Pine Decline while two were selected for their susceptibility. Seedlings were treated with five inoculation treatments: no wound (NW), wound only (W), wound+media (WM), Grosmannia huntii (GH) and Leptographium terebrantis (LT). After 118 days of exposure (AOT40=31ppm-hr(-1) for 2 ozone) seedling volume, dry matter, chlorophyll content, water potential and lesions were measured and analyzed using ANOVA procedures. Our results indicate that seedlings selected for their susceptibility to root infecting ophiostomatoid fungi were also more sensitive to ozone. Overall lesion length was greater on seedlings exposed to elevated ozone concentrations but was not specific to either root infecting ophiostomatoid fungi. PMID:26367706

  11. An infra-red imaging system for the analysis of tropisms in Arabidopsis thaliana seedlings

    SciTech Connect

    Orbovic, V.; Poff, K.L. )

    1990-05-01

    Since blue and green light will induce phototropism and red light is absorbed by phytochrome, no wavelength of visible radiation should be considered safe for any study of tropisms in etiolated seedlings. For this reason, we have developed an infra-red imaging system with a video camera with which we can monitor seedlings using radiation at wavelengths longer than 800 nm. The image of the seedlings can be observed in real time, recorded on a VCR and subsequently analyzed using the Java image analysis system. The time courses for curvature of seedlings differ in shape, amplitude, and lag time. This variability accounts for much of the noise in the measurement of curvature for a population of seedlings.

  12. Phytotoxicity and Transport of Gallium (Ga) in Rice Seedlings for 2-Day of Exposure.

    PubMed

    Yu, Xiao-Zhang; Feng, Xing-Hui; Feng, Yu-Xi

    2015-07-01

    Hydroponic experiments were conducted with rice seedlings to investigate the accumulation and phytotoxicity of gallium nitrate. A linear decrease in relative growth rate, transpiration rate and water use efficiency was observed in rice seedlings with increasing Ga concentrations. However, inhibition of these selected parameters was noted different at different Ga treatments. Relative growth rate was more sensitive towards Ga treatments. Phyto-transport of Ga was apparent, but recovery of Ga in different parts of rice seedlings varied significantly: roots were dominant site for Ga accumulation. The total accumulation rates of Ga were positively correlated to Ga concentrations. Results indicated that the addition of Ga did not cause deleterious effects on plant physiological functions over a 2-day exposure period. Large amounts of Ga were removed from the hydroponic solution through rice seedlings. Accumulation of Ga in plant tissues resulted in growth inhibition of rice seedlings. PMID:25634322

  13. Effects of topsoil removal on seedling emergence and species diversity

    SciTech Connect

    Winkel, V.K.; Ostler, W.K.

    1994-02-01

    Approximately 800 hectares on the US Department of Energy Nevada Test Site and vicinity are contaminated with Plutonium. As part of a cleanup effort, both the vegetation and the top 5--10 cm of soil may be removed. A study was developed to determine the effects of topsoil removal on seedling emergence and plant species diversity. Trial plots were prepared by removing 5, 10, or 20 cm of topsoil, seeding a mix of nine native species, mulching with straw, and then anchoring the straw with erosion netting. Additional plots (0 topsoil removal treatment) were lightly bladed to remove existing vegetation and then treated as above. Approximately 85 mm of supplemental irrigation was applied to help initiate germination during early spring. Seedling density data of seeded and nonseeded species was collected following emergence, and species diversity was calculated with the Shannon diversity index for the nonseeded species. Densities of seeded species either were unaffected by or increased with increased depth of topsoil removal. In general, densities of nonseeded species decreased with increased depth of topsoil removal. The number of species, species diversity and evenness also decreased with increased depth of topsoil removal. Initial emergence of seeded species is apparently unaffected by topsoil removal at this site.

  14. Carbohydrate metabolism in growing rice seedlings under arsenic toxicity.

    PubMed

    Jha, A B; Dubey, R S

    2004-07-01

    We studied in the seedlings of two rice cultivars (Malviya-36 and Pant-12) the effect of increasing levels of arsenic in situ on the content of sugars and the activity of several enzymes of starch and sucrose metabolism: alpha-amylase (EC 3.2.1.1), beta-amylase (EC 3.2.1.2), starch phosphorylase (EC 2.4.1.1), acid invertase (EC 3.2.1.26), sucrose synthase (EC 2.4.1.13) and sucrose phosphate synthase (EC 2.4.1.14). During a growth period of 10-20 d As2O3 at 25 and 50 microM in the growth medium caused an increase in reducing, non-reducing and total soluble sugars. An increased conversion of non-reducing to reducing sugars was observed concomitant with As toxicity. The activities of alpha-amylase, beta-amylase and sucrose phosphate synthase declined, whereas starch phosphorylase, acid invertase and sucrose synthase were found to be elevated. Results indicate that in rice seedlings arsenic toxicity causes perturbations in carbohydrate metabolism leading to the accumulation of soluble sugars by altering enzyme activity. Sucrose synthase possibly plays a positive role in synthesis of sucrose under As-toxicity. PMID:15310076

  15. Steryl Glycoside Formation in Seedlings of Nicotiana tabacum L. 1

    PubMed Central

    Bush, Parshall B.; Grunwald, C.

    1974-01-01

    Particulate enzyme preparations from tobacco seedlings (Nicotiana tabacum L.) were used in the synthesis of steryl glycoside. The data obtained by measuring cholesterol-4-14C incorporation generally agree with results obtained with UDP-glucose-14C. The in vitro reaction was linear for the first 10 minutes and had a pH optimum of 7.0 to 7.4. Addition of ATP activated while UDP-glucose inhibited slightly the reaction. In short term experiments, the percentage disappearance of endogenous and added sterol was about the same. Intact tobacco seedlings incorporated cholesterol-4-14C and sitosterol-4-14C into their steryl glycosides. The acylated steryl glycosides were more rapidly labeled than the nonacylated form. After 12 hours of incubation with cholesterol-4-14C, about 5% of the radioactivity was recovered as steryl glycoside and 12% as acylated steryl glycoside. Incubation for 12 hours with authentic cholesteryl-14C glucoside gave only a 4% acylation, and under these conditions 21% of the radioactivity was recovered as free cholesterol. It is suggested that acylated steryl glycosides may be formed through the acylation of steryl glycosides or the transfer of an acyl-glycosyl group to sterol. PMID:16658662

  16. Developmental reaction norms for water stressed seedlings of succulent cacti.

    PubMed

    Rosas, Ulises; Zhou, Royce W; Castillo, Guillermo; Collazo-Ortega, Margarita

    2012-01-01

    Succulent cacti are remarkable plants with capabilities to withstand long periods of drought. However, their adult success is contingent on the early seedling stages, when plants are highly susceptible to the environment. To better understand their early coping strategies in a challenging environment, two developmental aspects (anatomy and morphology) in Polaskia chichipe and Echinocactus platyacanthus were studied in the context of developmental reaction norms under drought conditions. The morphology was evaluated using landmark based morphometrics and Principal Component Analysis, which gave three main trends of the variation in each species. The anatomy was quantified as number and area of xylem vessels. The quantitative relationship between morphology and anatomy in early stages of development, as a response to drought was revealed in these two species. Qualitatively, collapsible cells and collapsible parenchyma tissue were observed in seedlings of both species, more often in those subjected to water stress. These tissues were located inside the epidermis, resembling a web of collapsible-cell groups surrounding turgid cells, vascular bundles, and spanned across the pith. Occasionally the groups formed a continuum stretching from the epidermis towards the vasculature. Integrating the morphology and the anatomy in a developmental context as a response to environmental conditions provides a better understanding of the organism's dynamics, adaptation, and plasticity. PMID:22479481

  17. Effects of aflatoxin on seedling growth and ultrastructure in plants.

    PubMed

    Crisan, E V

    1973-12-01

    Nineteen plants belonging to 11 species of the cruciferae were studied to determine the effects of aflatoxin B(1) on seed germination and seedling development. Germination was not inhibited in any test organism at a concentration of 100 mug of aflatoxin per ml of agar substrate. Inhibition of elongation of the hypocotyls and roots in the species studied varied from 29 to 93% and from 22 to 91% in the respective tissues. Lepidium sativum was the most susceptible plant studied and exhibited the maximal inhibitory response noted above at concentrations of 8 mug of aflatoxin per ml. The ultrastructure of Lepidium root cells treated with crystalline aflatoxin B(1) exhibited morphological changes characteristic of those found in aflatoxin-treated animal cells. In addition to changes in the cytoplasmic organelles, numerous ring-shaped nucleoli with prominent nucleolar caps were produced. The effect of aflatoxin on plant cells is compared with similar effects induced by actinomycin D. Seed germination and seedling development is discussed in relation to the effects of both compounds on deoxyribonucleic acid-dependent ribonucleic acid biosynthesis. PMID:4767301

  18. Enrichment and Analysis of Intact Phosphoproteins in Arabidopsis Seedlings

    PubMed Central

    Aryal, Uma K.; Ross, Andrew R. S.; Krochko, Joan E.

    2015-01-01

    Protein phosphorylation regulates diverse cellular functions and plays a key role in the early development of plants. To complement and expand upon previous investigations of protein phosphorylation in Arabidopsis seedlings we used an alternative approach that combines protein extraction under non-denaturing conditions with immobilized metal-ion affinity chromatography (IMAC) enrichment of intact phosphoproteins in Rubisco-depleted extracts, followed by identification using two-dimensional gel electrophoresis (2-DE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). In-gel trypsin digestion and analysis of selected gel spots identified 144 phosphorylated peptides and residues, of which only18 phosphopeptides and 8 phosphosites were found in the PhosPhAt 4.0 and P3DB Arabidopsis thaliana phosphorylation site databases. More than half of the 82 identified phosphoproteins were involved in carbohydrate metabolism, photosynthesis/respiration or oxidative stress response mechanisms. Enrichment of intact phosphoproteins prior to 2-DE and LC-MS/MS appears to enhance detection of phosphorylated threonine and tyrosine residues compared with methods that utilize peptide-level enrichment, suggesting that the two approaches are somewhat complementary in terms of phosphorylation site coverage. Comparing results for young seedlings with those obtained previously for mature Arabidopsis leaves identified five proteins that are differentially phosphorylated in these tissues, demonstrating the potential of this technique for investigating the dynamics of protein phosphorylation during plant development. PMID:26158488

  19. Mexican propolis flavonoids affect photosynthesis and seedling growth.

    PubMed

    King-Daz, Beatriz; Granados-Pineda, Jessica; Bah, Mustapha; Rivero-Cruz, J Fausto; Lotina-Hennsen, Blas

    2015-10-01

    As a continuous effort to find new natural products with potential herbicide activity, flavonoids acacetin (1), chrysin (2) and 4',7-dimethylnarangenin (3) were isolated from a propolis sample collected in the rural area of Mexico City and their effects on the photosynthesis light reactions and on the growth of Lolium perenne, Echinochloa crus-galli and Physalis ixocarpa seedlings were investigated. Acacetin (1) acted as an uncoupler by enhancing the electron transport under basal and phosphorylating conditions and the Mg(2+)-ATPase. Chrysin (2) at low concentrations behaved as an uncoupler and at concentrations up to 100 ?M its behavior was as a Hill reaction inhibitor. Finally, 4',7-dimethylnarangenin (3) in a concentration-dependent manner behaved as a Hill reaction inhibitor. Flavonoids 2 and 3 inhibited the uncoupled photosystem II reaction measured from water to 2,5-dichloro-1,4-benzoquinone (DCBQ), and they did not inhibit the uncoupled partial reactions measured from water to sodium silicomolybdate (SiMo) and from diphenylcarbazide (DPC) to diclorophenol indophenol (DCPIP). These results indicated that chrysin and 4',7-dimethylnarangenin inhibited the acceptor side of PS II. The results were corroborated with fluorescence of chlorophyll a measurements. Flavonoids also showed activity on the growth of seedlings of Lolium perenne and Echinochloa crus-galli. PMID:26318278

  20. Transformation of natural and synthetic estrogens by maize seedlings.

    PubMed

    Card, Marcella L; Schnoor, Jerald L; Chin, Yu-Ping

    2013-05-21

    In agricultural fields, crop plants may transform or degrade hormonally active compounds in manure used as fertilizer and thereby affect the overall endocrine-disrupting activity of agricultural runoff. This study examined the transformation of two natural steroid estrogens [17β-estradiol (17β-E2) and estrone (E1)] and two synthetic estrogen mimics [zeranol (α-ZAL) and zearalanone (ZAN)] by maize seedlings. Growing whole maize seedlings in hydroponic solutions of target estrogens resulted in both oxidative (i.e., 17β-E2 to E1 and α-ZAL to ZAN) and reductive (i.e., E1 to 17β-E2 and ZAN to α-ZAL) transformations. Although all four estrogens accumulated in maize roots as both parents and products, the shoots contained only 17β-E2 and α-ZAL, regardless of whether they were the parent or the product. Crude plant enzyme extracts led to substantial reductive transformations but created only trace amounts of oxidation products. In contrast, only oxidative transformations occurred in solutions exposed to plant-associated microbes. Thus, the combined effects of plant enzymes and plant-associated microbes account for the reversible transformations observed with whole plants. These effects are expected to generally decrease the overall estrogenicity of runoff from manure-fertilized fields. PMID:23488817

  1. Enrichment and Analysis of Intact Phosphoproteins in Arabidopsis Seedlings.

    PubMed

    Aryal, Uma K; Ross, Andrew R S; Krochko, Joan E

    2015-01-01

    Protein phosphorylation regulates diverse cellular functions and plays a key role in the early development of plants. To complement and expand upon previous investigations of protein phosphorylation in Arabidopsis seedlings we used an alternative approach that combines protein extraction under non-denaturing conditions with immobilized metal-ion affinity chromatography (IMAC) enrichment of intact phosphoproteins in Rubisco-depleted extracts, followed by identification using two-dimensional gel electrophoresis (2-DE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). In-gel trypsin digestion and analysis of selected gel spots identified 144 phosphorylated peptides and residues, of which only 18 phosphopeptides and 8 phosphosites were found in the PhosPhAt 4.0 and P3DB Arabidopsis thaliana phosphorylation site databases. More than half of the 82 identified phosphoproteins were involved in carbohydrate metabolism, photosynthesis/respiration or oxidative stress response mechanisms. Enrichment of intact phosphoproteins prior to 2-DE and LC-MS/MS appears to enhance detection of phosphorylated threonine and tyrosine residues compared with methods that utilize peptide-level enrichment, suggesting that the two approaches are somewhat complementary in terms of phosphorylation site coverage. Comparing results for young seedlings with those obtained previously for mature Arabidopsis leaves identified five proteins that are differentially phosphorylated in these tissues, demonstrating the potential of this technique for investigating the dynamics of protein phosphorylation during plant development. PMID:26158488

  2. Arsenic toxicity in soybean seedlings and their attenuation mechanisms.

    PubMed

    Armendariz, Ana L; Talano, Melina A; Travaglia, Claudia; Reinoso, Herminda; Wevar Oller, Ana L; Agostini, Elizabeth

    2016-01-01

    Even though vast areas contaminated with arsenic (As) are under soybean (Glycine max) cultivation, little is known about the growth and intrinsic antioxidant metabolism of soybean in response to As exposure. Thus, an evaluation was carried out of plant growth, root anatomy, antioxidant system and photosynthetic pigment content under arsenate (As(V)) and arsenite (As(III)) treatment. Soybean seedling growth was significantly affected at 25 μM or higher concentrations of As(V) or As(III), and the toxic effect on root growth was associated with cell death of root tips. Microscopic analysis of cross-sections of As-treated root showed a reduction in the cortex area, dark deposits in cortex cells and broken cells in the outer layer. Similarly, in the vascular cylinder, dark deposits within xylem vessel elements and phloem cell walls were observed. In all the analyzed parameters, the deleterious effect was more evident under As(III) than As(V) treatment. Arsenic-treated soybean seedlings showed increased activity of antioxidant enzymes [total peroxidases (Px) and superoxide dismutase (SOD)] in root and shoot harvested after 2 and 5 d of treatment. However, a reduction in chlorophyll content and an increase in membrane lipids peroxidation were observed. It is suggested that root structural alterations induced by As, such as the particular pattern of dark depositions in the vascular system, could be associated with an adaptation or detoxification mechanism to prevent As translocation to the aboveground tissues. PMID:26686284

  3. Developmental Reaction Norms for Water Stressed Seedlings of Succulent Cacti

    PubMed Central

    Rosas, Ulises; Zhou, Royce W.; Castillo, Guillermo; Collazo-Ortega, Margarita

    2012-01-01

    Succulent cacti are remarkable plants with capabilities to withstand long periods of drought. However, their adult success is contingent on the early seedling stages, when plants are highly susceptible to the environment. To better understand their early coping strategies in a challenging environment, two developmental aspects (anatomy and morphology) in Polaskia chichipe and Echinocactus platyacanthus were studied in the context of developmental reaction norms under drought conditions. The morphology was evaluated using landmark based morphometrics and Principal Component Analysis, which gave three main trends of the variation in each species. The anatomy was quantified as number and area of xylem vessels. The quantitative relationship between morphology and anatomy in early stages of development, as a response to drought was revealed in these two species. Qualitatively, collapsible cells and collapsible parenchyma tissue were observed in seedlings of both species, more often in those subjected to water stress. These tissues were located inside the epidermis, resembling a web of collapsible-cell groups surrounding turgid cells, vascular bundles, and spanned across the pith. Occasionally the groups formed a continuum stretching from the epidermis towards the vasculature. Integrating the morphology and the anatomy in a developmental context as a response to environmental conditions provides a better understanding of the organism's dynamics, adaptation, and plasticity. PMID:22479481

  4. Effects of soil and stem base heating on survival, resprouting and gas exchange of Acer and Quercus seedlings.

    PubMed

    Huddle, J A; Pallardy, S G

    1996-06-01

    Acer rubrum L., A. saccharum Marsh., Quercus alba L. and Q. rubra L. seedlings subjected to soil and stem base heat treatments showed rapid declines in rates of transpiration and photosynthesis. Reductions in photosynthetic rate were partly attributable to mesophyll inhibition. Quercus seedlings were less able to maintain transpiration and photosynthesis after heat treatment than Acer seedlings. Declines in rates of transpiration and photosynthesis of Quercus seedlings were observed 1 h after heat treatment and became more pronounced over time. In contrast, rates of transpiration and photosynthesis of Acer seedlings initially declined in response to heat treatment, partially recovered after one or two days, but then declined again six to eight days after the heat treatment. Observed changes in leaf water potential after heating were small, suggesting that hydraulic factors were not the primary signal eliciting the gas exchange response to soil and stem heating. Ultimately, the heat treatments caused stem die-back of most seedlings. For all species, seedlings that resprouted had a greater chance of surviving heat stress than seedlings that did not resprout. Despite the rapid loss of photosynthetic capacity in response to heat treatment in Quercus seedlings, survival was higher in Quercus seedlings than in Acer seedlings, and was associated with a greater capacity for resprouting. We suggest that the reduced allocation of resources toward recovery of photosynthesis in existing Quercus stems after heat stress is a physiological mechanism that facilitates resprouting and hence survival of Quercus seedlings after fire. PMID:14871712

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

    SciTech Connect

    Sloan, J.P.

    1994-07-01

    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.

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

    PubMed

    Lindquist, Erin Stewart; Carroll, C Ronald

    2004-12-01

    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

  7. Species-Specific Effects of Woody Litter on Seedling Emergence and Growth of Herbaceous Plants

    PubMed Central

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

    2011-01-01

    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

  8. Linking carbon and water relations to drought-induced mortality in Pinus flexilis seedlings.

    PubMed

    Reinhardt, Keith; Germino, Matthew J; Kueppers, Lara M; Domec, Jean-Christophe; Mitton, Jeffry

    2015-07-01

    Survival of tree seedlings at high elevations has been shown to be limited by thermal constraints on carbon balance, but it is unknown if carbon relations also limit seedling survival at lower elevations, where water relations may be more important. We measured and modeled carbon fluxes and water relations in first-year Pinus flexilis seedlings in garden plots just beyond the warm edge of their natural range, and compared these with dry-mass gain and survival across two summers. We hypothesized that mortality in these seedlings would be associated with declines in water relations, more so than with carbon-balance limitations. Rather than gradual declines in survivorship across growing seasons, we observed sharp, large-scale mortality episodes that occurred once volumetric soil-moisture content dropped below 10%. By this point, seedling water potentials had decreased below -5 MPa, seedling hydraulic conductivity had decreased by 90% and seedling hydraulic resistance had increased by >900%. Additionally, non-structural carbohydrates accumulated in aboveground tissues at the end of both summers, suggesting impairments in phloem-transport from needles to roots. This resulted in low carbohydrate concentrations in roots, which likely impaired root growth and water uptake at the time of critically low soil moisture. While photosynthesis and respiration on a leaf area basis remained high until critical hydraulic thresholds were exceeded, modeled seedling gross primary productivity declined steadily throughout the summers. At the time of mortality, modeled productivity was insufficient to support seedling biomass-gain rates, metabolism and secondary costs. Thus the large-scale mortality events that we observed near the end of each summer were most directly linked with acute, episodic declines in plant hydraulic function that were linked with important changes in whole-seedling carbon relations. PMID:26116925

  9. Linking carbon and water limitations to drought-induced mortality of Pinus flexilis seedlings

    USGS Publications Warehouse

    Reinhardt, Keith; Germino, Matthew J.; Kueppers, Lara M.; Domec, Jean-Christophe; Mitton, Jeffry

    2015-01-01

    Survival of tree seedlings at high elevations has been shown to be limited by thermal constraints on carbon balance, but it is unknown if carbon relations also limit seedling survival at lower elevations, where water relations may be more important. We measured and modeled carbon fluxes and water relations in first-yearPinus flexilisseedlings in garden plots just beyond the warm edge of their natural range, and compared these with dry-mass gain and survival across two summers. We hypothesized that mortality in these seedlings would be associated with declines in water relations, more so than with carbon-balance limitations. Rather than gradual declines in survivorship across growing seasons, we observed sharp, large-scale mortality episodes that occurred once volumetric soil-moisture content dropped below 10%. By this point, seedling water potentials had decreased below ?5?MPa, seedling hydraulic conductivity had decreased by 90% and seedling hydraulic resistance had increased by >900%. Additionally, non-structural carbohydrates accumulated in aboveground tissues at the end of both summers, suggesting impairments in phloem-transport from needles to roots. This resulted in low carbohydrate concentrations in roots, which likely impaired root growth and water uptake at the time of critically low soil moisture. While photosynthesis and respiration on a leaf area basis remained high until critical hydraulic thresholds were exceeded, modeled seedling gross primary productivity declined steadily throughout the summers. At the time of mortality, modeled productivity was insufficient to support seedling biomass-gain rates, metabolism and secondary costs. Thus the large-scale mortality events that we observed near the end of each summer were most directly linked with acute, episodic declines in plant hydraulic function that were linked with important changes in whole-seedling carbon relations.

  10. Cryopreservation affects ROS-induced oxidative stress and antioxidant response in Arabidopsis seedlings.

    PubMed

    Chen, Guan-Qun; Ren, Li; Zhang, Jie; Reed, Barbara M; Zhang, Di; Shen, Xiao-Hui

    2015-02-01

    Plant recovery status after cryopreservation by vitrification had a negative relationship to the oxidative stress induced by reactive oxygen species (ROS). Arabidopsis thaliana seedlings germinated for 48 h or 72 h with different survival tolerances were examined at five steps of cryopreservation, to determine the role of ROS (O2(-), H2O2 and OH) and antioxidant systems (SOD, POD, CAT, AsA and GSH) in cryo-injury. In addition, the effects of the steps on membrane lipid peroxidation were studied using malondialdehyde (MDA) as an indicator. The results indicated that H2O2-induced oxidative stress at the steps of dehydration and rapid warming was the main cause of cryo-injury of 48-h seedlings (high survival rate) and 72-h seedlings (no survival). The H2O2 was mainly generated in cotyledons, shoot tips and roots of seedlings as indicated by Amplex Red staining. Low survival of 72-h seedlings was associated with severe membrane lipid peroxidation, which was caused by increased OH generation activity and decreased SOD activity. The antioxidant-related gene expression by qRT-PCR and physiological assays suggested that the antioxidant system of 48-h seedlings were activated by ROS, and they mounted a defense against oxidative stress. A high level of ROS led to the weakening of the antioxidant system of 72-h seedlings. Correlation analysis indicated that enhanced antioxidant enzymes activities contributed to the high survival rate of 48-h seedlings, which could reflect by cryopreservation of antioxidant mutant seedlings. This model system indicated that elevated CAT activity and AsA content were determinants of cryogenic stress tolerance, whose manipulation could improve the recovery of seedlings after cryopreservation. PMID:25489814

  11. [Growth, survival and herbivory of seedlings in Brosimum alicastrum (Moraceae), a species from the Neotropical undergrowth].

    PubMed

    Ballina-Gmez, H S; Iriarte-Vivar, S; Orellana, R; Santiago, L S

    2008-12-01

    Growth responses, survival, and herbivory, on seedlings of Brosimum alicastrum were studied in a neotropical Mexican forest. We selected 122 seedlings and divided them into three groups assigned to defoliation treatments: control or 0 (n=21), 50 (n=51) and 90% (n=50). Every 4 months during two years we measured seedling growth (in terms of relative growth rate in biomass, leaf area growth, produced leaves and height growth) and survival. In addition, we evaluated every 12 months pathogen damage and insect herbivory using a 2 mm(-2) grid. Separately, we estimated mammal herbivory in 3-month old seedlings that were selected within a plot of 500 m x 10 m (N=1095). Pathogen damage and insect herbivory were evaluated within the same plot in 113 seedlings. We found that 50% defoliated seedlings showed compensatory responses in all growth parameters. Relative growth rate and height growth also had a compensatory response in seedlings at 90% defoliation. Relative growth rate and leaf area growth gradually decreased with time although height growth seedling showed an opposite pattern. Leaves produced were not affected by time. Estimated seedling survival probability increased with defoliation to a maximum of 97%, decreasing at 24 month to 37%. Mammal herbivory was more frequent and severe than herbivory caused by pathogens and insects. In some cases, mammal herbivory produced total defoliation. Compensatory growth in leaf area growth, produced leaves and height growth seedling suggest a synergic compensatory mechanism expressed in a whole-plant growth biomass (relative growth rate). Compensation and survival results suggest trade-offs at the leaf level, such as leaf area growth and produced leaves versus chemical defenses, respectively. PMID:19419101

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

    PubMed

    Suz, Laura M; Martn, Mara P; Fischer, Christine R; Bonet, Jos A; Colinas, Carlos

    2010-06-01

    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

  13. Ethanolamide Oxylipins of Linolenic Acid Can Negatively Regulate Arabidopsis Seedling Development[C][W

    PubMed Central

    Keereetaweep, Jantana; Blancaflor, Elison B.; Hornung, Ellen; Feussner, Ivo; Chapman, Kent D.

    2013-01-01

    N-Acylethanolamines (NAEs) are fatty-acid derivatives with potent biological activities in a wide range of eukaryotic organisms. Polyunsaturated NAEs are among the most abundant NAE types in seeds of Arabidopsis thaliana, and they can be metabolized by either fatty acid amide hydrolase (FAAH) or by lipoxygenase (LOX) to low levels during seedling establishment. Here, we identify and quantify endogenous oxylipin metabolites of N-linolenoylethanolamine (NAE 18:3) in Arabidopsis seedlings and show that their levels were higher in faah knockout seedlings. Quantification of oxylipin metabolites in lox mutants demonstrated altered partitioning of NAE 18:3 into 9- or 13-LOX pathways, and this was especially exaggerated when exogenous NAE was added to seedlings. When maintained at micromolar concentrations, NAE 18:3 specifically induced cotyledon bleaching of light-grown seedlings within a restricted stage of development. Comprehensive oxylipin profiling together with genetic and pharmacological interference with LOX activity suggested that both 9-hydroxy and 13-hydroxy linolenoylethanolamides, but not corresponding free fatty-acid metabolites, contributed to the reversible disruption of thylakoid membranes in chloroplasts of seedling cotyledons. We suggest that NAE oxylipins of linolenic acid represent a newly identified, endogenous set of bioactive compounds that may act in opposition to progression of normal seedling development and must be depleted for successful establishment. PMID:24151297

  14. 90sr uptake by 'pinus ponderosa' and 'pinus radiata' seedlings inoculated with ectomycorrhizal fungi

    SciTech Connect

    Entry, J.A.; Rygiewicz, P.T.; Emmingham, W.H.

    1994-01-01

    In the study, the authors inoculated P. ponderosa and P. radiata seedlings with one of five isolates of ectomycorrhizal fungi; inoculated and nonincoculated (control) seedlings were compared for their ability to remove Sr90 from an organic growth medium. Seedlings were grown for 3 months in a growth chamber in glass tubes containing 165 cu cm of sphagnum peat moss and perlite and, except in the controls, the fungal inoculum. After 3 months, 5978 Bq of Sr90 in 1 ml of sterile, distilled, deionized water was added. Seedlings were grown for an additional month and then harvested. P. ponderosa seedlings that were inoculated with ectomycorrhizal fungi accumulated 3.0-6.0% of the Sr90; bioconcentration ratios ranged from 98-162. Inoculated P. radiata seedlings accumulated 6.0-6.9% of the Sr90; bioconcentration ratios ranged from 88-133. Noninoculated P. ponderosa and P. radiata seedlings accumulated only 0.6 and 0.7% of the Sr90 and had bioconcentration ratios of 28 and 27, respectively.

  15. Light-hormone interaction in the red-light-induced suppression of photomorphogenesis in rice seedlings.

    PubMed

    Roy, Ansuman; Sahoo, Dinabandhu; Tripathy, Baishnab C

    2016-03-01

    Red light perceived by the shoot bottom suppresses photomorphogenesis in rice seedlings mediated by phytochrome A. Shoots of these seedlings grown in red light having their shoot bottom exposed were deficient in chlorophyll and accumulated high concentration of trans-zeatin riboside. However, reduced presence of isopentynyl adenosine, dihydrozeatin riboside was observed in shoots of red-light-grown non-green seedlings in comparison to green seedling. The message abundance of cytokinin receptor (OsHK5), transporters (OsENT1, OsENT2), and response regulators (OsRR4, OsRR10) was downregulated in these red-light-grown non-green seedlings. Attenuation of greening process was reversed by application of exogenous cytokinin analogue, benzyladenine, or supplementing red light with blue light. In the same vein, the suppression of gene expression of cytokinin receptor, transporters, and type-A response regulators was reversed in red-light-grown seedlings treated with benzyladenine suggesting that the disarrayed cytokinin (CK) signaling cascade is responsible for non-greening of seedlings grown in red light. The reversal of red-light-induced suppression of photomorphogenesis by blue light and benzyladenine demonstrates the interaction of light and cytokinin signaling cascades in the regulation of photomorphogenesis. Partial reversal of greening process by exogenous application of benzyladenine suggests, apart from CKs perception, transportation and responsiveness, other factors are also involved in modulation of suppression of photomorphogenesis by red light. PMID:25902895

  16. Association of growth related seedling traits in Acacia senegal under arid environment of western Rajasthan.

    PubMed

    Pancholy, Anjly; Jindal, S K; Singh, S K; Pathak, Rakesh

    2015-07-01

    Climatic models and predictions indicate increase in aridity world over due to global warming. Arid environments occupy about one third land area of the world. A. senegal is the most important dryland resource of western Rajasthan desert ecosystem. The seeds of 13 low and high seed yielding exotic and indigenous provenances were evaluated for diversity and interrelationship among growth related seedling traits targeting establishment and end use of this species. Under the present study most of the growth related seedling traits varied within and amongst provenances. Highly significant correlation of dry biomass per plant of more than 72% with root length (73.3%), collar diameter (72.2%), shoot dryweight (99.7%), root dry weight (95.7%) and seedling length (79.9%) under the present study may be used for early selection. Similarly, highly significant positive correlation of seedling length with seven out of 12 growth related seedling traits validate strong inherent association of these traits under strong genetic control and are amenable for selection. Significant negative correlation in number of nodules per plant with root/shoot length ratio (-57.6%) and no correlation with 10 out of 12 growth related seedling traits tested advocate emphasis on other growth related seedling traits in selection of elite A. senegal genotypes for afforestation. The non significant associations suggest that per cent germination was independent of other characters and could be selected separately. PMID:26364473

  17. Varying impacts of cervid, hare and vole browsing on growth and survival of boreal tree seedlings.

    PubMed

    Lyly, Mari; Klemola, Tero; Koivisto, Elina; Huitu, Otso; Oksanen, Lauri; Korpimäki, Erkki

    2014-01-01

    The negative impacts of mammalian herbivores on plants have been studied quite extensively, but typically with only a single herbivore species at a time. We conducted a novel comparison of the browsing effects of voles, hares and cervids upon the growth and survival of boreal tree seedlings. This was done by excluding varying assemblages of these key mammalian herbivores from silver birch, Scots pine and Norway spruce seedlings for 3 years. We hypothesised that the pooled impacts of the herbivores would be greater than that of any individual group, while the cervids would be the group with the strongest impact. Growth of birch seedlings advanced when cervids were excluded whereas growth of seedlings accessible to cervids was hindered. Survival of all seedlings was lowest when they were accessible to voles and voles plus hares, whereas cervids seemed not to influence seedling survival. Our results show that the impact of herbivores upon woody plants can be potent in the boreal forests, but the mechanism and strength of this link depends on the tree and herbivore species in question. Risk of abated stand regeneration appears highest for the deciduous birch, though there is need for seedling protection also in coniferous stands. The clear cervid-mediated growth limitation of birch also indicates potential for a trophic cascade effect by mammalian top predators, currently returning to boreal ecosystems. PMID:24036931

  18. Effect of arsenic on growth, oxidative stress, and antioxidant system in rice seedlings.

    PubMed

    Shri, Manju; Kumar, Smita; Chakrabarty, Debasis; Trivedi, Prabodh Kumar; Mallick, Shekhar; Misra, Prashant; Shukla, Devesh; Mishra, Seema; Srivastava, Sudhakar; Tripathi, Rudra D; Tuli, Rakesh

    2009-05-01

    The physiological, biochemical, and proteomic changes in germinating rice seedlings were investigated under arsenic stress. A marked decrease in germination percentage, shoot, and root elongation as well as plant biomass was observed with arsenic treatments, as compared to control, whereas accumulation of arsenic and malondialdehyde (MDA) in seedlings were increased significantly with increasing arsenic concentration (both AsIII and AsV). The up-regulation of some antioxidant enzyme activities and the isozymes of superoxide dismutase (SOD, EC 1.15.1.1), ascorbate peroxidase (APX, EC 1.11.1.11), peroxidase (POD, EC 1.11.1.7), and glutathione reductase (GR, 1.6.4.2) substantiated that arsenic accumulation generated oxidative stress, which was more pronounced in As(III) treatment. We also studied the protective effect of reduced glutathione (GSH) and cysteine (Cys) to As(III)/As(V) stressed seedlings. Both GSH and Cys imparted enhanced tolerance to seedlings against arsenic stress. Seedlings growth improved while level of MDA declined significantly when GSH and Cys were supplemented to As(III)/As(V) treatments suggesting GSH and Cys-mediated protection against oxidative stress. The arsenic content was highest in roots of seedlings grown in As(III) in the presence of GSH/Cys. However, in case of As(V) plus GSH or Cys, the arsenic content in seedlings was highest in shoots. The results are suggestive of differential metabolism of As(III) and As(V) in rice. PMID:19013643

  19. Retention of cotyledons is crucial for resprouting of clipped oak seedlings

    PubMed Central

    Yi, Xianfeng; Liu, Changqu

    2014-01-01

    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. PMID:24888417

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

    NASA Astrophysics Data System (ADS)

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

    2009-09-01

    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.

  1. Seedling Diversity in Hydatellaceae: Implications for the Evolution of Angiosperm Cotyledons

    PubMed Central

    Sokoloff, Dmitry D.; Remizowa, Margarita V.; Macfarlane, Terry D.; Tuckett, Renee E.; Ramsay, Margaret M.; Beer, Anton S.; Yadav, Shrirang R.; Rudall, Paula J.

    2008-01-01

    Background and Aims Cotyledon number has long been a primary morphological feature distinguishing monocots from other angiosperms. Recent placement of Hydatellaceae near the early-divergent angiosperm order Nymphaeales, rather than in the monocot order Poales, has prompted reassessment of seedling morphology in this poorly known family. Methods Seedlings of six species representing all eco-geographical groups of Hydatellaceae are described using light and scanning electron microscopy. Key Results Two seedling types were discovered. Material examined of Trithuria submersa, T. bibracteata, T. austinensis and T. filamentosa possess a transparent bilobed sheathing structure that surrounds the main axis below the first foliage leaf. The seed coat is attached to the sheathing structure. Seedlings of Trithuria lanterna and T. konkanensis lack a sheathing structure, and the seed coat is attached to a short, narrow lateral outgrowth on the main axis of the seedling. Conclusions The sheathing structure that is present in seedlings of some Hydatellaceae could be homologized with the two united cotyledons of water lilies. It also resembles the single cotyledon of some monocots, and hence demonstrates a possible pathway of the origin of a monocot-like embryo, though no homology is implied. The sheathing structure is reduced in Trithuria lanterna and T. konkanensis, and the short, narrow outgrowth of its seedling could represent a single cotyledon. This synapomorphy suggests that the only Indian species of Hydatellaceae, T. konkanensis, is closer to the northern Australian T. lanterna than to the south-western Australian T. bibracteata. PMID:18032428

  2. Sharing rotting wood in the shade: ectomycorrhizal communities of co-occurring birch and hemlock seedlings.

    PubMed

    Poznanovic, Sarah K; Lilleskov, Erik A; Webster, Christopher R

    2015-02-01

    Coarse woody debris (CWD) is an important nursery environment for many tree species. Understanding the communities of ectomycorrhizal fungi (ECMF)and the effect of ECMF species on tree seedling condition in CWD will elucidate the potential for ECMF-mediated effects on seedling dynamics. In hemlock-dominated stands, we characterized ECMF communities associated with eastern hemlock (Tsuga canadensis (L.) Carr) and yellow birch (Betula alleghaniensis Britt) seedling pairs growing on CWD. Seedling foliage and CWD were analyzed chemically, and seedling growth, canopy cover, and canopy species determined. Thirteen fungal taxa, 12 associated with birch, and 6 with hemlock, were identified based on morphology and ITS sequencing. Five species were shared by co-occurring birch and hemlock, representing 75% of ectomycorrhizal root tips. Rarified ECMF taxon richness per seedling was higher on birch than hemlock. Nonmetric multidimensional scaling revealed significant correlations between ordination axes, the mutually exclusive ECMF Tomentella and Lactarius spp., foliar N and K, CWD pH, and exchangeable Ca and Mg. Seedlings colonized by Lactarius and T. sublilacina differed significantly in foliar K and N, and CWD differed in exchangeable Ca and Mg. CWD pH and nutrient concentrations were low but foliar macro-nutrient concentrations were not. We hypothesize that the dominant ECMF are adapted to low root carbohydrate availability typical in shaded environments but differ in their relative supply of different nutrients. PMID:25091153

  3. Role of Potassium and Malate in Nitrate Uptake and Translocation by Wheat Seedlings 1

    PubMed Central

    Blevins, Dale G.; Barnett, Neal M.; Frost, William B.

    1978-01-01

    Wheat seedlings (Triticum vulgare) treated with 1 mm KNO3 or NaNO3, in the presence of 0.2 mm CaSO4, were compared during a 48-hour period with respect to nitrate uptake, translocation, accumulation and reduction; cation uptake and accumulation; and malate accumulation. Seedlings treated with KNO3 absorbed and accumulated more nitrate, had higher nitrate reductase levels in leaves but less in roots, accumulated 17 times more malate in leaves, and accumulated more of the accompanying cation than seedlings treated with NaNO3. Within seedlings of each treatment, changes in nitrate reductase activity and malate accumulation were parallel in leaves and in roots. Despite the great difference in malate accumulation, leaves of the KNO3-treated seedlings had only slightly greater levels of phosphoenolpyruvate carboxylase than leaves of NaNO3-treated seedlings. NADP-malic enzyme levels increased only slightly in leaves and roots of both KNO3- and NaNO3-treated seedlings. The effects of K+ and Na+ on all of these parameters can best be explained by their effects on nitrate translocation, which in turn affects the other parameters. In a separate experiment, we confirmed that phosphoenolpyruvate carboxylase activity increased about 2-fold during 36 hours of KNO3 treatment, and increased only slightly in the KCl control. PMID:16660606

  4. Herbivory and seedling performance in a fragmented temperate forest of Chile

    NASA Astrophysics Data System (ADS)

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

    2007-11-01

    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.

  5. Growth responses and adaptations of Fraxinus pennsylvanica seedlings to flooding

    SciTech Connect

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

    1980-01-01

    Flooding induced several physiological and morphological changes in Fraxinus pennsylvanica seedlings, with stomatal closure among the earliest responses. Subsequent changes included: reduction in dry weight increment of roots, stems, and leaves; formation of hypertrophied lenticles and production of adventitious roots on submerged portions of the stem above the soil line; leaf necrosis; and leaf abscission. After 15 days of stomatal closure as a results of flooding, stomata began to reopen progressively until stomata aperture was similar in flooded and unflooded plants. Adventitious roots began to form at about the time stomatal reopening began. As more adventitious roots formed, elongated, and branched, the stomata opened further. The formation of adventitious roots was in important adaptation for flooding tolerance as shown by the high efficiency of adventitious roots in absorption of water and in high correlation between the production of adventitious roots and stomatal reopening. 6 figures, 2 tables.

  6. Scaling the respiratory metabolism to phosphorus relationship in plant seedlings

    PubMed Central

    Wang, Zhi-Qiang; Huang, Heng; Deng, Jian-Ming; Liu, Jian-Quan

    2015-01-01

    There are empirical indications of an isometric scaling relationship between plants’ respiratory metabolism rates and nitrogen contents. To test the hypothesis that there may be a similar relationship between plants’ respiratory metabolism and phosphorus contents we used data obtained from 150 laboratory and field-grown seedlings representing 30 herbaceous species and 20 woody deciduous species. Our results show that whole-plant respiration rates strongly scaled to the 0.81-power of the whole-plant phosphorus content, across wide ranges of growth conditions and functional classifications. Moreover, we also found a similar scaling exponent between whole-plant respiration rates and total nitrogen contents for the same set of samples. The similarities of the metabolic scaling relationships suggest that similar mechanisms may be involved in the transport and storage of phosphorus and nitrogen in plants. PMID:26560344

  7. Scaling the respiratory metabolism to phosphorus relationship in plant seedlings.

    PubMed

    Wang, Zhi-Qiang; Huang, Heng; Deng, Jian-Ming; Liu, Jian-Quan

    2015-01-01

    There are empirical indications of an isometric scaling relationship between plants' respiratory metabolism rates and nitrogen contents. To test the hypothesis that there may be a similar relationship between plants' respiratory metabolism and phosphorus contents we used data obtained from 150 laboratory and field-grown seedlings representing 30 herbaceous species and 20 woody deciduous species. Our results show that whole-plant respiration rates strongly scaled to the 0.81-power of the whole-plant phosphorus content, across wide ranges of growth conditions and functional classifications. Moreover, we also found a similar scaling exponent between whole-plant respiration rates and total nitrogen contents for the same set of samples. The similarities of the metabolic scaling relationships suggest that similar mechanisms may be involved in the transport and storage of phosphorus and nitrogen in plants. PMID:26560344

  8. The structure of the stem endodermis in etiolated pea seedlings

    NASA Technical Reports Server (NTRS)

    Sack, F. D.

    1987-01-01

    Differentiation of the endodermis was examined in third internodes of etiolated Pisum sativum L. cv. Alaska seedlings. The endodermis in young internodes contains large, sedimented amyloplasts; in older internodes, a casparian strip differentiates and the endodermis becomes depleted of starch except for the proximal region of the stem, which retains sedimented amyloplasts and remains graviresponsive. Sedimentation occurs in the hook but does not occur consistently until cells reach the base of the hook, where the axis becomes vertical, rapid cell elongation starts, and amyloplast diameter increases substantially. Contact between endoplasmic reticulum and amyloplasts was observed. Endoplasmic reticulum is not distributed polarly with respect to gravity. No symplastic or apoplastic blockages exist in the endodermis at the level of the stem where lateral gradients may be established during tropic curvature.

  9. Specific Inhibition of Phototropism in Corn Seedlings 1

    PubMed Central

    Schmidt, Werner; Hart, James; Filner, Philip; Poff, Kenneth L.

    1977-01-01

    Geotropism was used as a control for the specificity of potential inhibitors of phototropism by the coleoptiles of corn (Zea mays) seedlings. The compounds tested fall into three categories showing: (a) no inhibition of either phototropism or geotropism (KCl); (b) nonspecific inhibition of both phototropism and geotropism (KCN); and (c) specific inhibition of phototropism (KI, NaN3, and phenylacetic acid). Simultaneous irradiation of coleoptiles with phototropically inert light in addition to the phototropically active blue light also results in an inhibition of phototropism. Since azide, iodide, and phenylacetic acid are known to interact with flavins while a simultaneous irradiation with a phototropically inert light may depopulate the first triplet state of flavins, these data support the hypothesis that the photoreceptor pigment for phototropism in corn is a flavin. PMID:16660174

  10. Specific guanine nucleotide binding by membranes from Cucurbita pepo seedlings.

    PubMed

    Jacobs, M; Thelen, M P; Farndale, R W; Astle, M C; Rubery, P H

    1988-09-30

    A microsomal membrane preparation from hypocotyls of dark-grown Cucurbita pepo L. (zucchini) seedlings contains specific high-affinity binding sites for the non-hydrolyzable GTP analog guanosine 5'-[gamma-thio]triphosphate (GTP-gamma-S). Both the binding affinity and the pattern of binding specificity for GTP and guanine nucleoside triphosphate analogs are shared with the more thoroughly characterized animal G-proteins that are known to be involved in signal transduction. The sensitivity of GTP-gamma-S binding to Mg+2 ions and temperature was similar to that reported for rabbit liver G-protein, although the plant complex dissociated more readily. GTP-gamma-S could be recovered unchanged from the binding complex. Proteins (Mr 33 and 50 kDa) present in zucchini membrane preparations were revealed by immunoblotting with antiserum specific for the alpha subunit of platelet GS. These may be homologous to animal G-proteins. PMID:3052446

  11. Mapping Salinity Tolerance during Arabidopsis thaliana Germination and Seedling Growth

    PubMed Central

    DeRose-Wilson, Leah; Gaut, Brandon S.

    2011-01-01

    To characterize and dissect genetic variation for salinity tolerance, we assessed variation in salinity tolerance during germination and seedling growth for a worldwide sample of Arabidopsis thaliana accessions. By combining QTL mapping, association mapping and expression data, we identified genomic regions involved in salinity response. Among the worldwide sample, we found germination ability within a moderately saline environment (150 mM NaCl) varied considerable, from >90% among the most tolerant lines to complete inability to germinate among the most susceptible. Our results also demonstrated wide variation in salinity tolerance within A. thaliana RIL populations and identified multiple genomic regions that contribute to this variation. These regions contain known candidate genes, but at least four of the regions contain loci not yet associated with salinity tolerance response phenotypes. Our observations suggest A. thaliana natural variation may be an underutilized resource for investigating salinity stress response. PMID:21857956

  12. Correlations between polyamine ratios and growth patterns in seedling roots

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

  13. Biosynthesis of trigonelline from nicotinate mononucleotide in mungbean seedlings.

    PubMed

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

    2008-01-01

    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

  14. Cyanogenic Lipids: Utilization during Seedling Development of Ungnadia speciosa.

    PubMed

    Selmar, D; Grocholewski, S; Seigler, D S

    1990-06-01

    Large amounts of cyanogenic lipids (esters of 1 cyano-2-methylprop-2-ene-1-ol with C:20 fatty acids) are stored in the seeds of Ungnadia speciosa. During seedling development, these lipids are completely consumed without liberation of free HCN to the atmosphere. At the same time, cyanogenic glycosides are synthesized, but the total amount is much lower (about 26%) than the quantity of cyanogenic lipids formerly present in the seeds. This large decrease in the total content of cyanogens (HCN-potential) demonstrates that at least 74% of cyanogenic lipids are converted to noncyanogenic compounds. Whether the newly synthesized cyanogenic glycosides are derived directly from cyanogenic lipids or produced by de novo synthesis is still unknown. Based on the utilization of cyanogenic lipids for the synthesis of noncyanogenic compounds, it is concluded that these cyanogens serve as storage for reduced nitrogen. The ecophysiological significance of cyanolipids based on multifunctional aspects is discussed. PMID:16667514

  15. Effects of seed mass on seedling success in Artocarpus heterophyllus L., a tropical tree species of north-east India

    NASA Astrophysics Data System (ADS)

    Khan, M. L.

    2004-03-01

    I examined the effects of seed mass on performance of seedlings of Artocarpus heterophyllus L. (Moraceae), a large evergreen late successional shade-tolerant tree species in three contrasting light conditions. Seed mass varied many fold from 1.5 to 14 g in A. heterophyllus. Germination and germination time showed a significant correlation with seed mass. Germination differed significantly among three light regimes (50%, 25% and 3%). Seed mass and light level significantly affected seedling survival. The seedlings that emerged from large seeds survived better than those from small seeds under all light regimes. Survival of seedlings was maximum in 25% light regime for all seed mass classes but did not differ significantly from that at 50% light regime. Survival was significantly lower in 3% light as compared to 50% and 25% light regimes. Seedling vigor (expressed in terms of seedling height, leaf area and dry weight) was also significantly affected by seed mass and light regimes. Seedlings that emerged from larger seeds and grew under 50% light regime produced the heaviest seedlings, while those resulting from smaller seeds and grown under 3% light regime produced the lightest seedlings. Resprouting capacity of seedlings after clipping was significantly affected by seed mass and light regime. Seedlings emerging from larger seeds were capable of resprouting several times successively. Resprouting was more pronounced under 50% and 25% light regimes as compared to 3% light. Success of A. heterophyllus regeneration appears to be regulated by an interactive effect of seed mass and light regime.

  16. Seasonal differences in needle gas exchange between mature branches and seedlings of Pinus ponderosa

    SciTech Connect

    Houpis, J.L.J.; Anderson, P.D. )

    1991-05-01

    In 1990, an interactive study was initiated to understand the differing physiological and morphological response of mature tissue and seedling tissue to stress. The study was conducted at the Air Pollution and Climate Change Exposure Facility in a Pinus ponderosa seed production orchard at the US Forest Service Tree Improvement Center in Chico, CA. The orchard consists of clonal trees and the authors have planted half-sibling seedlings which correspond to the mature clones which were measured. Both the mature trees and seedlings were regularly irrigated and fertilized. The result is that they have minimized the genetic and environmental differences that might otherwise influence the physiological differences between mature and seedling tissue. One of the physiological parameters which was measured was seasonal and diurnal gas exchange using a LICOR 6200. They measured gas exchange in November 1989, March, July, and October 1990. They found that throughout the year, all gas exchange components (eg. photosynthesis, transpiration, stomatal conductance) were significantly greater for seedling tissue. Photosynthetic differences were greater during early October, with diurnal mean rates of 1.1 {mu}mol m{sup {minus}2}s{sup {minus}1} and 0.5 {mu}mol m{sup {minus}2}s{sup {minus}1} for seedling and mature tissue, respectively. Transpiration differences were greater during early October, with diurnal mean rates of 2.2 mmol m{sup {minus}2}2{sup {minus}1} and 1.2 mmol m{sup {minus}2}s{sup {minus}1} for seedling and mature tissue, respectively. Finally, gas exchange differences between seedling and mature tissue were greater for current needles than one-year old needles. The results of this study demonstrate that gas exchange differences between seedling and mature tissue observed in the field may be the result of inherent physiological differences, and not merely genetic and environmental differences.

  17. Seedlingherbivore interactions: insights into plant defence and regeneration patterns

    PubMed Central

    Barton, Kasey E.; Hanley, Mick E.

    2013-01-01

    Background Herbivores have the power to shape plant evolutionary trajectories, influence the structure and function of vegetation, devastate entire crops, or halt the spread of invasive weeds, and as a consequence, research into plantherbivore interactions is pivotal to our understanding of plant ecology and evolution. However, the causes and consequences of seedling herbivory have received remarkably little attention, despite the fact that plants tend to be most susceptible to herbivory during establishment, and this damage can alter community composition and structure. Scope In this Viewpoint article we review why herbivory during early plant ontogeny is important and in so doing introduce an Annals of Botany Special Issue that draws together the latest work on the topic. In a synthesis of the existing literature and a collection of new studies, we examine several linked issues. These include the development and expression of seedling defences and patterns of selection by herbivores, and how seedling selection affects plant establishment and community structure. We then examine how disruption of the seedlingherbivore interaction might affect normal patterns of plant community establishment and discuss how an understanding of patterns of seedling herbivory can aid our attempts to restore semi-natural vegetation. We finish by outlining a number of areas where more research is required. These include a need for a deeper consideration of how endogenous and exogenous factors determine investment in seedling defence, particularly for the very youngest plants, and a better understanding of the phylogenetic and biogeographical patterns of seedling defence. There is also much still be to be done on the mechanisms of seedling selection by herbivores, particularly with respect to the possible involvement of volatile cues. These inter-related issues together inform our understanding of how seedling herbivory affects plant regeneration at a time when anthropogenic change is likely to disrupt this long-established, but all-too-often ignored interaction. PMID:23925939

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

    PubMed

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

    2009-10-01

    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

  19. Germination requirements and seedling responses to water availability and soil type in four eucalypt species

    NASA Astrophysics Data System (ADS)

    Schtz, Wolfgang; Milberg, Per; Lamont, Byron B.

    2002-03-01

    We conducted experiments on seed germination, seedling survival and seedling growth of four Eucalyptus species to identify factors that might explain why they are restricted to the two major soil types in southwestern Australia, deep sands ( E. macrocarpa, E. tetragona) and lateritic loam ( E. loxophleba, E. wandoo). At high temperatures (28 C), germination in darkness was lower for the two 'loam species' than for the 'sand species', while there were no differences in light or at low temperatures (10 C). Germination commenced earlier, and was faster in the sand species than in the loam species, but was almost inhibited in all species by -1.0 MPa. E. tetragona proved the most drought-tolerant in terms of germination level and seedling survival. Seedlings of the sand species had much longer roots two weeks after germination in the absence of water stress, and the roots of more seedlings continued to elongate under moderate water stress (-1.0 MPa), than the two loam species. Roots were longer in all species, except E. macrocarpa, at -0.5 MPa than at -0.1 MPa, despite seedlings having a smaller mass and hypocotyl length. As water availability declined, there was a tendency for the sand species to survive longer on sand than on loam while soil type had no effect on the loam species. Pattern and duration of seedling survival of the loam species was similar to that of the sand species despite their smaller seeds. We conclude that seedlings from the large-seeded sand species are able to penetrate the soil profile faster and deeper, but that they are not less prone to drying soils than seedlings from the small-seeded loam species. Instead, seed size and germination speed are important prerequisites to cope successfully with unstable soil surfaces and to exploit the rapidly descending water in deep sands.

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

    SciTech Connect

    Franco, A.C.; Nobel, P.S. )

    1988-12-01

    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.

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

    PubMed

    Gruffman, Linda; Palmroth, Sari; Näsholm, Torgny

    2013-06-01

    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

  2. Light limitation and litter of an invasive clonal plant, Wedelia trilobata, inhibit its seedling recruitment

    PubMed Central

    Qi, Shan-Shan; Dai, Zhi-Cong; Miao, Shi-Li; Zhai, De-Li; Si, Chun-Can; Huang, Ping; Wang, Rui-Ping; Du, Dao-Lin

    2014-01-01

    Background and Aims Invasive clonal plants have two reproduction patterns, namely sexual and vegetative propagation. However, seedling recruitment of invasive clonal plants can decline as the invasion process proceeds. For example, although the invasive clonal Wedelia trilobata (Asteraceae) produces numerous seeds, few seedlings emerge under its dense population canopy in the field. In this study it is hypothesized that light limitation and the presence of a thick layer of its own litter may be the primary factors causing the failure of seedling recruitment for this invasive weed in the field. Methods A field survey was conducted to determine the allocation of resources to sexual reproduction and seedling recruitment in W. trilobata. Seed germination was also determined in the field. Effects of light and W. trilobata leaf extracts on seed germination and seedling growth were tested in the laboratory. Key Results Wedelia trilobata blooms profusely and produces copious viable seeds in the field. However, seedlings of W. trilobata were not detected under mother ramets and few emerged seedlings were found in the bare ground near to populations. In laboratory experiments, low light significantly inhibited seed germination. Leaf extracts also decreased seed germination and inhibited seedling growth, and significant interactions were found between low light and leaf extracts on seed germination. However, seeds were found to germinate in an invaded field after removal of the W. trilobata plant canopy. Conclusions The results indicate that lack of light and the presence of its own litter might be two major factors responsible for the low numbers of W. trilobata seedlings found in the field. New populations will establish from seeds once the limiting factors are eliminated, and seeds can be the agents of long-distance dispersal; therefore, prevention of seed production remains an important component in controlling the spread of this invasive clonal plant. PMID:24825293

  3. Temperature, precipitation and biotic interactions as determinants of tree seedling recruitment across the tree line ecotone.

    PubMed

    Tingstad, Lise; Olsen, Siri Lie; Klanderud, Kari; Vandvik, Vigdis; Ohlson, Mikael

    2015-10-01

    Seedling recruitment is a critical life history stage for trees, and successful recruitment is tightly linked to both abiotic factors and biotic interactions. In order to better understand how tree species' distributions may change in response to anticipated climate change, more knowledge of the effects of complex climate and biotic interactions is needed. We conducted a seed-sowing experiment to investigate how temperature, precipitation and biotic interactions impact recruitment of Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) seedlings in southern Norway. Seeds were sown into intact vegetation and experimentally created gaps. To study the combined effects of temperature and precipitation, the experiment was replicated across 12 sites, spanning a natural climate gradient from boreal to alpine and from sub-continental to oceanic. Seedling emergence and survival were assessed 12 and 16 months after sowing, respectively, and above-ground biomass and height were determined at the end of the experiment. Interestingly, very few seedlings were detected in the boreal sites, and the highest number of seedlings emerged and established in the alpine sites, indicating that low temperature did not limit seedling recruitment. Site precipitation had an overall positive effect on seedling recruitment, especially at intermediate precipitation levels. Seedling emergence, establishment and biomass were higher in gap plots compared to intact vegetation at all temperature levels. These results suggest that biotic interactions in the form of competition may be more important than temperature as a limiting factor for tree seedling recruitment in the sub- and low-alpine zone of southern Norway. PMID:26065402

  4. A proteomic analysis of cold stress responses in rice seedlings.

    PubMed

    Cui, Suxia; Huang, Fang; Wang, Jie; Ma, Xiao; Cheng, Yongsheng; Liu, Jinyuan

    2005-08-01

    Using proteomic analysis, an investigation aimed at a better understanding of the molecular adaptation mechanisms of cold stress was carried out in rice (Oryza sativa). The seedlings were exposed to a progressively low temperature stress treatment from normal temperature to 15, 10, and 5 degrees C. Proteins were extracted from the leaves collected from both control and stressed seedlings. By fractionation, approximately 1700 protein spots were separated and visualized on CBB-stained 2-D gels. Sixty protein spots were found to be up-regulated in responding to the progressively low temperature stress and displayed different dynamic patterns. As an initial work, 41 of these proteins were identified using MALDI-TOF MS or ESI/MS/MS. These cold responsive proteins, besides two proteins of unknown function, include four factors of protein biosynthesis, four molecular chaperones, two proteases, and eight enzymes involved in biosynthesis of cell wall components, seven antioxidative/detoxifying enzymes, and proteins linked to energy pathway, as well as a protein involved in signal transduction. The functional proteomes illuminate the facts, at least in plant cell, that protein quality control mediated by chaperones and proteases and enhancement of cell wall components play important roles in tolerance to cold stress. Using TargetP program, the subcellular localization of the identified proteins was analyzed. Proteins (43.9%) were predicted to be located in the chloroplasts, implying that chloroplast proteome is virtually subjective to cold stress. The physiological implications, revealed from the experimental data, are discussed in context of a complex metabolic network in plant cells responsive to cold stress. PMID:16078185

  5. Interaction between hydrotropism and gravitropism in seedling roots

    NASA Astrophysics Data System (ADS)

    Kobayashi, A.; Takahashi, A.; Yamazaki, Y.; Kakimoto, Y.; Higashitani, A.; Fujii, N.; Takahashi, H.

    Roots display positive hydrotropism in response to a moisture gradient, which could play a role in avoiding drought stress. Because roots also respond to other stimuli such as gravity, touch and light and exhibit gravitropism, thigmotropism and phototropism, respectively, their growth orientation is determined by interaction among those tropisms. We have demonstrated the interaction between hydrotropism and gravitropism. For example, 1) agravitropic roots of pea mutant strongly respond to a moisture gradient and show positive hydrotropism by overcoming gravitropism, 2) in wild type pea roots hydrotropism is weak but pronounced when rotated on clinostat, 3) cucumber roots are positively gravitropic on the ground but become hydrotropic in microgravity, and 4) maize roots change their growth direction depending on the intensities of both gravistimulation and hydrostimulation. Here we found that Arabidopsis roots could display strong hydrotropism by overcoming gravitropism. It was discovered that amyloplasts in the columella cells are rapidly degraded upon exposure to a moisture gradient. Thus, degradation of amyloplasts could reduce the responsiveness to gravity, which could pronounce the hydrotropic response. In hydrotropically stimulated roots of pea seedlings, however, we could not observe a rapid degradation of amyloplasts in the columella cells. These results suggest that mechanism underlying the interaction between hydrotropism and gravitropism differs among plant species. To further study the molecular mechanism of hydrotropism and its interaction with gravitropism, we isolated unique mutants of Arabidopsis of which roots showed either ahydrotropism, reduced hydrotropism or negative hydrotropic response and examined their gravitropism, phototropism, waving response, amyloplast degradation and elongation growth. Based on the characterization of hydrotropic mutants, we will attempt to compare the mechanisms of the two tropisms and to clarify their cross talk for controlling the directional growth of seedling roots.

  6. Cadmium interferes with maintenance of auxin homeostasis in Arabidopsis seedlings.

    PubMed

    Hu, Yan Feng; Zhou, Guoying; Na, Xiao Fan; Yang, Lijing; Nan, Wen Bin; Liu, Xu; Zhang, Yong Qiang; Li, Jiao Long; Bi, Yu Rong

    2013-07-15

    Auxin and its homeostasis play key roles in many aspects of plant growth and development. Cadmium (Cd) is a phytotoxic heavy metal and its inhibitory effects on plant growth and development have been extensively studied. However, the underlying molecular mechanism of the effects of Cd stress on auxin homeostasis is still unclear. In the present study, we found that the root elongation, shoot weight, hypocotyl length and chlorophyll content in wild-type (WT) Arabidopsis seedlings were significantly reduced after exposure to Cd stress. However, the lateral root (LR) formation was markedly promoted by Cd stress. The level and distribution of auxin were both greatly altered in primary root tips and cotyledons of Cd-treated plants. The results also showed that after Cd treatment, the IAA content was significantly decreased, which was accompanied by increases in the activity of the IAA oxidase and alteration in the expression of several putative auxin biosynthetic and catabolic genes. Application of the auxin transport inhibitor, 1-naphthylphthalamic acid (NPA) and 1-naphthoxyacetic acid (1-NOA), reversed the effects of Cd on LR formation. Additionally, there was less promotion of LR formation by Cd treatment in aux1-7 and pin2 mutants than that in the WT. Meanwhile, Cd stress also altered the expression of PINs and AUX1 in Arabidopsis roots, implying that the auxin transport pathway is required for Cd-modulated LR development. Taken together, these findings suggest that Cd stress disturbs auxin homeostasis through affecting auxin level, distribution, metabolism, and transport in Arabidopsis seedling. PMID:23683587

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

    NASA Technical Reports Server (NTRS)

    Orbovic, V.; Poff, K. L.

    1997-01-01

    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.

  8. Species-specific effects on topsoil development affect Quercus ilex seedling performance

    NASA Astrophysics Data System (ADS)

    Puerta-Piero, Carolina; Gmez, Jos Mara; Zamora, Regino

    2006-01-01

    We illustrate experimentally the importance of species-specificity in the soil-mediated interactions among plants inhabiting heterogeneous landscapes. Topsoils from nine microhabitats were used to experimentally grow Quercus ilex acorns in the laboratory. We recorded germination, emergence, acorn left and seedling performance (HGR, biomass and root allocation). Different topsoils had very contrasting physico-chemical properties, creating a heterogeneous arena. This heterogeneity translated to differences in seedling performance, since emergence and survival differed among topsoils. However, nutrient content in topsoils did not appear to benefit seedling performance. In addition, there were strong correlations among parameters of plant performance indicating a consistency of the effect of topsoil type on Q. ilex seedlings. This implies that it is crucial to consider the specificity of the interaction between plants to wholly understand the structure of plant communities. Species-specific interactions may play an important role in the organization and dynamic of plants spatial distribution.

  9. Use of TREGRO to simulate the effects of ozone on the growth of red spruce seedlings

    SciTech Connect

    Laurence, J.A.; Kohut, R.J.; Amundson, R.G. )

    1993-08-01

    TREGRO, a model developed to simulate the growth of sapling red spruce (Picea rubens Sarg.), was parameterized to grow 2- to 3-yr-old seedlings. Results of the simulation compared favorably to actual growth of seedlings used in a field study of the effects of ozone and acidic precipitation on tree physiology and development. Furthermore, a 10-yr simulation produced a modeled tree that corresponded to saplings used in another field experiment. Additional simulations were conducted to compare predicted effects of ozone on seedling growth to those measured in controlled experiments. Based on the performance of the model, we believe TREGRO can be used effectively to simulate both seedling and sapling red spruce growth, and the potential effects of ozone on the development of the trees. 11 refs., 6 figs., 3 tabs.

  10. Litter cover of the invasive tree Melaleuca quinquenervia influences seedling emergence and survival

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accumulated plant litter biomass on forest floors likely influences seedling emergence and survival. Natural enemies of dominant plants may also influence these processes. We examined these assumptions in mature stands of the invasive tree Melaleuca quinquenervia (melaleuca) using four sequential ...

  11. Improvement of the zygote utilization and reduction of the seedling loss in the early stage of seedling production of Sargassum thunbergii (Fucales, Phaeophyta)

    NASA Astrophysics Data System (ADS)

    Liu, Wei; Wu, Haiyi; Liu, Mengxia; Duan, Delin

    2015-10-01

    Artificial seedling production of Sargassum thunbergii is an effective way to relieve pressure on natural resources. In order to improve the utilization of zygotes and reduce the loss of seedlings, studies on the characteristic of the zygotes release, the development of rhizoids, the attachment of germlings, and the influence of jet washing were conducted. Results show that the percent of zygotes released was increased with time in the first 60 h. The capacity of germlings attached to the substratum was significantly increased, especially coincident with the time of the new rhizoids emerged and elongated. The detachment rate of germlings significantly decreased with the delay of starting time of jet washing or the reduction of jet washing velocity. However, the jet washing at any level applied in the experiment could cause considerable loss of germlings within the 20 days after the attachment. Our study provided some parameters to optimize the operation in the early stage of seedling production.

  12. Effects of substrates composed of biosolids on the production of Eucalyptus viminalis, Schinus terebinthifolius and Mimosa scabrella seedlings and on the nutritional status of Schinus terebinthifolius seedlings.

    PubMed

    Bonnet, B R P; Wisniewsk, C; Reissmann, C B; Nogueira, A C; Andreoli, C V; Barbieri, S J

    2002-01-01

    Six substrates made up with heated and composted anaerobic biosolid were tested for the production of Eucalyptus viminalis, Schinus terebinthifolius and Mimosa scabrella forest seedlings in a nursery in Southern Brazil. The produced seedlings were statistically evaluated in relation to height, stem diameter, height/stem diameter ratio, aerial and root dry biomass, survival, and also for nutritional status on S. terebinthifolius seedlings. As a function of their high pH, heated biosolids turned out to be viable only in low composition percentages. Composted biosolids turned out to be sufficiently suitable in percentages between 30% and 60% of the substratum--whose Mn and Zn concentrations relate the nutrient contents in theseedlings -with use viability up to 100% in substratum composition. PMID:12479477

  13. Effect of long-term drought on carbon allocation and nitrogen uptake of Pinus sylvestris seedlings

    NASA Astrophysics Data System (ADS)

    Pumpanen, Jukka; Aaltonen, Heidi; Lindén, Aki; Köster, Kajar; Biasi, Christina; Heinonsalo, Jussi

    2015-04-01

    Weather extremes such as drought events are expected to increase in the future as a result of climate change. The drought affects the allocation of carbon assimilated by plants e.g. by modifying the root to shoot ratio, amount of fine roots and the amount of mycorrhizal fungal hyphae. We studied the effect of long term drought on the allocation of carbon in a common garden experiment with 4-year-old Pinus sylvestris seedlings. Half of the seedlings were exposed to long-term drought by setting the soil water content close to wilting point for over two growing seasons whereas the other half was grown in soil close to field capacity. We conducted a pulse labelling with 13CO2 in the end of the study by injecting a known amount of 13C enriched CO2 to the seedlings and measuring the CO2 uptake and distribution of 13C to the biomass of the seedlings and to the root and rhizosphere respiration. In addition, we studied the effect of drought on the decomposition of needle litter and uptake of nitrogen by 15N labelled needles buried in the soil in litter bags. The litterbags were collected and harvested in the end of the experiment and the changes in microbial community in the litterbags were studied from the phospholipid fatty acid (PLFA) composition. We also determined the 15N isotope concentrations from the needles of the seedlings to study the effect of drought on the nitrogen uptake of the seedlings. Our results indicate that the drought had a significant effect both on the biomass allocation of the seedlings and on the microbial species composition. The amount of carbon allocated belowground was much higher in the seedlings exposed to drought compared to the control seedlings. The seedlings seemed to adapt their carbon allocation to long-term drought to sustain adequate needle biomass and water uptake. The seedlings also adapted their osmotic potential and photosynthesis capacity to sustain the long-term drought as was indicated by the measurements of osmotic potential and photosynthetic light response.

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

    PubMed Central

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

    2013-01-01

    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. PMID:23894211

  15. Methyl Jasmonate- and Light-Induced Glucosinolate and Anthocyanin Biosynthesis in Radish Seedlings.

    PubMed

    Al-Dhabi, Naif Abdullah; Arasu, Mariadhas Valan; Kim, Sun Ju; RomijUddin, Md; Park, Woo Tae; Lee, Sook Young; Park, Sang Un

    2015-07-01

    Radish sprouts and young seedlings are considered important dietary vegetables in Asian countries. In this study, we investigated the levels of glucosinolate and anthocyanin accumulation in radish seedlings in response to light and methyl jasmonate (MeJA) treatments. MeJA facilitated the accumulation of glucosinolate and anthocyanins under light conditions. The glucosinolate and anthocyanin contents in the radish seedlings that were exposed to light after MeJA treatment were higher than those of the seedlings that were grown in the dark without MeJA. At a concentration of 100 ?M, MeJA led to the greatest accumulation of the most glucosinolates under both light and dark conditions. Under light conditions, the levels of glucoraphenin, glucoerucin, and glucotropaeolin accumulation were 1.53-, 1.60-, and 1.30-fold higher, respectively, than those of the control. Remarkable accumulations of glucobrassicin were observed under light conditions (4.4-, 6.7-, and 7.8-fold higher than that of the control following the application of 100, 300, and 500 ?M MeJA, respectively). The level of cyanidin in the 300 ?M MeJA-treated seedlings was double of that in the control without MeJA treatment. The highest level of pelargonidin was observed after treatment with 500 ?M MeJA under light conditions; this level was 1.73 times higher than that in the control. A similar trend of anthocyaninaccumulation was observed in the radish seedlings following MeJA treatment under dark conditions, but the levels of anthocyanins were considerably lower in the seedlings that were grown in the dark. Our findings suggest that light and low concentrations of MeJA enhance the accumulations of glucosinolates and anthocyanins during the development of radish seedlings. PMID:26411013

  16. Primate extirpation from rainforest fragments does not appear to influence seedling recruitment.

    PubMed

    Chaves, Oscarm M; Arroyo-Rodrguez, Vctor; Martnez-Ramos, Miguel; Stoner, Kathryne E

    2015-04-01

    Primates are important seed dispersers, especially of large-seeded tree species, but the impact that these animals have on seedling recruitment is unclear. Evidence suggests that forest regeneration might be disrupted in forest fragments in which primates were extirpated. We tested this hypothesis by assessing seedling recruitment in 3 forest fragments occupied (OF) by primates, 3 fragments unoccupied (UF) by primates, and 3 areas within a continuous forest (CF) in the Lacandona rainforest, Mexico. Species and stem densities of tree, palm and liana seedlings were recorded over 16 months. Individuals were classified according to dispersal mode: large-seeded animal-dispersed (LS), small- and medium-seeded animal-dispersed (SS), and abiotically-dispersed species (AD). We assessed the influence of primate presence, adult tree assemblage, and fragment spatial metrics (size, age, distance to nearest fragment, and distance to continuous forest) on seedling assemblages. We recorded 6879 seedlings belonging to 90 species, and 59 genera in 405 1-m(2) plots. Both seedlings and adults showed similar differences in species and stem densities of LS, SS and AD species among forest types, suggesting that seedling assemblages were strongly influenced by the adult assemblages. The recruitment of each LS species varied among study sites, but evidence supporting higher recruitment enhancement of these species in continuous forest and occupied fragments was weak. Distance to continuous forest was the unique fragment spatial metric related (negatively) to the recruitment of LS species. Thus, primate extirpation does not appear to disrupt seedling assemblages in the Lancandona rainforest. Nevertheless, we cannot reject the hypothesis that certain LS species such as Spondias radlkoferi may be affected by the extirpation of primates. PMID:25556633

  17. Quantifying the effects of seed arrival and environmental conditions on tropical seedling community structure.

    PubMed

    Paine, C E Timothy; Harms, Kyle E

    2009-05-01

    Though it is recognized that both stochastic and deterministic processes structure all communities, empirical assessments of their relative importance are rare, particularly within any single community. In this paper, we quantify the dynamic effects of dispersal assembly and niche assembly on the seedling layer in a diverse neotropical rain forest. The two theories make divergent predictions regarding the roles of seed arrival and environmental heterogeneity in generating community structure. Put simply, dispersal assembly posits that the stochasticity inherent to seed arrival structures communities, whereas niche assembly suggests that heterogeneity in post-dispersal environmental conditions is more important. We experimentally sowed 15,132 seeds of eight tree species at varying levels of density and diversity. Every six months we censused the seedlings that germinated and assessed the abiotic and biotic conditions of each plot. We assessed the density, diversity, and species composition of three nested subsets of the seedling layer: seedlings germinated from sown seeds, all seedlings germinated between July 2003 and 2004, and all woody seedlings. We partitioned the variance in density and diversity of each subset of the seedling layer into components representing seed-addition treatments and environmental conditions at 6- to 12-month intervals. Seed additions initially explained more variance in the density and diversity than did environmental heterogeneity for seven of eight sown species, but explained little variance in the density or diversity of the entire seedling layer. Species composition was better explained by seed-addition treatments than by environmental heterogeneity for all three subsets and in all time periods. Nevertheless, the variance in community structure explained by seed-addition treatments declined over the two years following germination, presaging shifts in the relative importance of dispersal assembly and niche assembly. Our study quantifies how dispersal assembly and niche assembly may vary among the components of an ecological community and shift dynamically through time. PMID:19142667

  18. Seed-litter-position drives seedling establishment in grassland species under recurrent drought.

    PubMed

    Wellstein, C

    2012-11-01

    Changes in land use and climate interfere with grassland ecosystem processes. Here I experimentally investigated the combined effects of land-use change related litter cover and contrasting water supply on seedling emergence. In this context, the role of the initial relative position of seeds, i.e. seeds on top of the litter versus seeds beneath the litter in interaction with water supply has not been investigated so far. I hypothesised that facilitative effects of litter on seedling emergence occur when seeds are covered by litter and deteriorate when litter covers the ground and seeds fall on it (seeds on top of the litter). Further, I hypothesised that the importance of seed position for seedling emergence will increase under conditions of recurrent drought. I performed a controlled pot experiment on seedling emergence of three common European grassland species (Pimpinella saxifraga, Leontodon autumnalis, Sanguisorba officinalis) by experimental manipulations of litter and water availability. Seedling emergence under moist conditions showed no significant differences between each litter position compared to the control across species. In contrast, under recurrent drought, seedling emergence was significantly higher below the litter compared to seeds on top of the litter and the control (i.e. no litter). In abandoned land, seedling emergence may be limited when seeds fall on ground-covering litter. In contrast, in grasslands with regular low-intensity land use, seedling emergence may be enhanced when a moderate level of litter covers seeds at the end of the growing season. Protective mechanisms that occur with seeds positioned beneath litter are particularly important under recurrent drought. PMID:22822918

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

    PubMed Central

    Konjevi?, R.; Grubii?, D.; Nekovi?, Mirjana

    1989-01-01

    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. PMID:16666668

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

    NASA Astrophysics Data System (ADS)

    Kozeko, Liudmyla

    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.

  1. Impacts of seedling herbivory on plant competition and implications for species coexistence

    PubMed Central

    Hanley, M. E.; Sykes, R. J.

    2009-01-01

    Background and Aims Although the causes and consequences of seedling herbivory for plant community composition are well understood, the mechanisms by which herbivores influence plant species recruitment to the established phase remain less clear. The aim was to examine how variation in the intensity of seedling herbivory interacts with growth-defence trade-offs and herbivore feeding preferences to affect plant community development. Methods Using 14-d-old seedlings of Trifolium pratense and T. repens, relative growth and susceptibility to herbivory by the snail Helix aspersa was quantified to elucidate putative growth-defence trade-offs for these species. Then mixed assemblages of 14-d-old Trifolium seedlings were exposed to herbivory by zero, two, five or ten snails and determined how variation in the intensity of herbivory affected competitive interactions into the mature phase (as measured by total plant biomass at 120 d old). Key Results In the absence of herbivory, communities were dominated by T. pratense; a result expected on the basis that it yielded larger and presumably more competitive seedlings. However, when seedlings were exposed to herbivory, the balance of competition shifted. At low levels of herbivory (two snails), both Trifolium species contributed equally to total plant biomass. More intense herbivory (five snails) resulted in almost total mortality of T. pratense and dominance of the mature community by T. repens. The most intense herbivory (ten snails) effectively removed all seedlings from the experimental community. Conclusions The study illustrates a mechanism whereby spatio-temporal fluctuations in seedling herbivory, when coupled with species-specific variation in competitive ability and sensitivity to herbivore attack, can differentially influence plant recruitment into the mature phase. This mechanism may be a key element in our attempts to understand plant species coexistence, since fluctuations in plant recruitment are fundamental to the many theories that view coexistence as a consequence of a spatio-temporal lottery for dominance over regeneration micro-sites. PMID:19351683

  2. Properties of Plasma Membrane from Pea Root Seedlings under Altered Gravity

    NASA Astrophysics Data System (ADS)

    Klymchuk, D.; Baranenko, V.; Vorobyova, T. V.; Kurylenko, I.; Chyzhykova, O.; Dubovoy, V.

    In this study, the properties of pea (Pisum sativum L.) plasma membrane were examined to determine how the membrane structure and functions are regulated in response to clinorotation (2 rev/min) conditions. Membrane preparations enriched by plasma membrane vesicles were obtained by aqueous two-phase partitioning from 6-day seedling roots. The specific characteristics of H^+-ATPase, lípid composition and peroxidation intensity as well as fluidity of lipid bilayer were analysed. ATP hydrolytic activity was inhibited by ortovanadate and was insensitive to aside and nitrate in sealed plasma membrane vesicles isolated from both clinorotated and control seedlings. Plasma membrane vesicles from clinorotated seedlings in comparison to controls were characterised by increase in the total lipid/protein ratio, ATP hydrolytic activity and intensifying of lipid peroxidation. Sitosterol and campesterol were the predominant free sterol species. Clinorotated seedlings contained a slightly higher level of unsaturated fatty acid than controls. Plasma membrane vesicles were labelled with pyrene and fluorescence originating from monomeric (I_M) molecules and excimeric (I_E) aggregates were measured. The calculated I_E/I_M values were higher in clinorotated seedlings compared with controls reflecting the reduction in membrane microviscosity. The involvement of the changes in plasma membrane lipid content and composition, fluidity and H^+-ATPase activity in response of pea seedlings to altered gravity is discussed.

  3. Multi-Stage Metering Mechanism for Transplanting of Vegetable Seedlings in Paper Pots

    NASA Astrophysics Data System (ADS)

    Nandede, B. M.; Raheman, H.

    2015-12-01

    A multi-stage rotating cup type metering mechanism was developed for transplanting of vegetable seedlings of tomato, brinjal and chili raised in paper pots. The developed setup consisted of a seedling feeding wheel, metering wheel, fixed slotted plate, seedling delivery tube, furrow opener, furrow closer and a power transmission system. Its evaluation was carried out with pot seedlings of tomato, brinjal and chili of 8-11 cm height at five forward speeds (0.6, 0.9, 1.2, 2.2 and 3.2 km/h) and two plant spacings (45 and 60 cm) in controlled soil bin condition. The mean values of feeding efficiency, conveying efficiency, planting efficiency and overall efficiency of the multistage metering unit were observed to be higher than 90 % for forward speeds of 0.6 to 2.2 km/h. With further increase in speed to 3.2 km/h, the feeding and conveying efficiency were observed to be higher than 90 %, whereas, the planting efficiency drastically reduced to around 50 % due to the problem in getting the pot seedlings vertically in the furrow. Also the seedlings were falling into the furrow at an angle greater than 70° to the vertical, hence not suitable for transplanting.

  4. Root architecture and hydraulic conductance in nutrient deprived Pistacia lentiscus L. seedlings.

    PubMed

    Trubat, Roman; Cortina, Jordi; Vilagrosa, Alberto

    2012-12-01

    Plants respond to low nutrient availability by modifying root morphology and root system topology. Root responses to nitrogen (N) and phosphorus (P) limitation may affect plant capacity to withstand water stress. But studies on the effect of nutrient availability on plant ability to uptake and transport water are scarce. In this study, we assess the effect of nitrogen and phosphorus limitation on root morphology and root system topology in Pistacia lentiscus L seedlings, a common Mediterranean shrub, and relate these changes to hydraulic conductivity of the whole root system. Nitrogen and phosphorus deprivation had no effect on root biomass, but root systems were more branched in nutrient limited seedlings. Total root length was higher in seedlings subjected to phosphorus deprivation. Root hydraulic conductance decreased in nutrient-deprived seedlings, and was related to the number of root junctions but not to other architectural traits. Our study shows that changes in nutrient availability affect seedling water use by modifying root architecture. Changes in nutrient availability should be taken into account when evaluating seedling response to drought. PMID:22717626

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

    NASA Astrophysics Data System (ADS)

    Alagna, Adriana; Fernndez, Toms Vega; Terlizzi, Antonio; Badalamenti, Fabio

    2013-03-01

    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.

  6. [Soil nutrient status of pure birch and larch plantations based on their seedlings bioassay].

    PubMed

    Liu, Zhong-ling; Wang, Qing-cheng; Sun, Xin-xin

    2011-08-01

    One-year-old birch (Betula platyphylla) and larch (Larix olgensis) seedlings were respectively planted in pots with the soils taken from 35-year-old pure birch and larch plantations, and the seedlings growth, biomass increment, foliar nutrient content, and soil nutrient status were monitored, aimed to evaluate the fertility levels of the two soils and the possible interspecific interaction in mixed larch-birch forest. Birch soil had significantly higher contents of total N and available N than larch soil, while larch soil had significantly higher contents of total P, available P, and total K than birch soil (P < 0.05). In the first growth season, the height and collar diameter growth and the biomass accumulation of birch seedlings growing on birch soil were 69%, 52%, and 65% (P < 0.05) higher than those growing on larch soil, and the larch seedlings also had 12%, 8%, and 37% gains of the indices, respectively. The foliar N concentration of both larch and birch seedlings growing on birch soil was higher than that on larch soil, while the foliar P concentration was higher when the seedlings were growing on larch soil than on birch soil. The birch soil had higher content of available N because of the higher litterfall, while the larch soil had greater available P because of the higher P mobilizing effect. It was predicted that in mixed birch-larch forest, the complementary interaction of soil N and P could benefit the growth of the two tree species. PMID:22097360

  7. Seed Priming with Selenium: Consequences for Emergence, Seedling Growth, and Biochemical Attributes of Rice.

    PubMed

    Khaliq, Abdul; Aslam, Farhena; Matloob, Amar; Hussain, Saddam; Geng, Mingjian; Wahid, Abdul; ur Rehman, Hafeez

    2015-08-01

    The present study was undertaken to appraise the role of selenium priming for improving emergence and seedling growth of basmati rice. Seeds of two fine rice cultivars (Super and Shaheen Basmati) were primed with concentrations of 15, 30, 45, 60, 75, 90, and 105?molL(-1) selenium. Untreated dry- and hydro-primed seeds were maintained as the control and positive control, respectively. Selenium priming resulted in early commencement of emergence, triggered seedling growth irrespective of rice cultivar over untreated control, and was more effective than hydro-priming except at higher concentrations. Lower electrical conductivity of seed leachates, reduced lipid peroxidation, greater ?-amylase activity, higher soluble sugars, and enhanced activities of enzymatic antioxidants (superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), and glutathione peroxidase (GPX)) were observed in seeds primed with selenium. Rice seedlings derived from selenium-primed seeds exhibited more chlorophyll contents, while total phenolics were comparable with those of the control seedlings. The improved starch metabolism, greater membrane stability, and increased activity of antioxidants were considered as possible mechanisms responsible for such improvements in emergence and seedling vigor of rice mediated by selenium priming. Priming with selenium (15-60?molL(-1)) favored rice emergence and seedling growth. Nevertheless, soaking seeds in relatively concentrated (90 and 105?molL(-1)) selenium solution had overall detrimental effects. PMID:25690516

  8. Within-population variability influences early seedling establishment in four Mediterranean oaks

    NASA Astrophysics Data System (ADS)

    Gonzlez-Rodrguez, Victoria; Barrio, Isabel C.; Villar, Rafael

    2012-05-01

    Regeneration of Mediterranean forests is severely limited. Multiple abiotic factors are known to constrain the establishment of woody seedlings at its first phases, such as summer drought or excessive incident radiation, but less attention has been paid to the role of intra-specific variation in seedling performance. In this study we investigate the relative influence of environment (light availability, soil moisture and summer irrigation) and intrinsic factors (seed mass and maternal origin) as determinants of within-population variability in the early establishment of four coexisting Mediterranean oaks (Quercus ilex, Quercus suber, Quercus faginea and Quercus pyrenaica), from emergence and early growth to second-year survival in a field experiment. Seed size was a poor predictor of seed and seedling success. Instead, mother identity showed a stronger effect on seedling performance. Time and percentage of emergence, establishment success and morphological traits varied among seedlings from different maternal trees but main drivers for each variable were different for each species. In addition to a direct effect, in many cases mother-related intrinsic traits and seed mass influenced the effects of environmental conditions on seedling performance. The role of intrinsic factors was masked under ameliorated conditions (i.e. summer irrigation), indicating the relevant role of within-population variability to cope with highly heterogeneous and unpredictable Mediterranean environments.

  9. Different responses to shade of evergreen and deciduous oak seedlings and the effect of acorn size

    NASA Astrophysics Data System (ADS)

    Ke, Guo; Werger, Marinus J. A.

    1999-11-01

    An evergreen oak species, Cyclobalanopsis multinervis, and a deciduous oak species, Quercus aliena var. acuteserrata were grown from acorns under two light levels (full sunlight and shade at about 18 % of full sunlight, simulating the light intensities in forest clearings and gaps, respectively) for one growing season. Three hypotheses were tested: (i) the deciduous species grows faster than the evergreen species in forest gaps and clearings; (ii) the deciduous species responds more strongly in terms of growth and morphology to variation in light climate than the evergreen species; and (iii) seedling size is positively correlated to acorn size. The results showed: (i) at both light levels, the deciduous seedlings gained significantly more growth in biomass and height than the evergreen seedlings; (ii) both species produced significantly more biomass in full sunlight than in shade, without showing any significant difference in height between treatments. Increase in light intensity improved the growth of the deciduous seedlings more strongly; (iii) at a similar age, the deciduous seedlings showed a greater response in leaf morphology and biomass allocation to variation in light levels, but when compared at a similar size, biomass allocation patterns did not differ significantly between species; (iv) bigger acorns tended to produce larger seedlings, larger leaf sizes and more leaf area, between and within species. These differences demonstrate that the deciduous species is gap-dependent and has the advantage over the evergreen species in forest gaps and clearings.

  10. Acorn cotyledons are larger than their seedlings' need: evidence from artificial cutting experiments

    PubMed Central

    Yi, Xianfeng; Wang, Zhenyu; Liu, Changqu; Liu, Guoqiang; Zhang, Mingming

    2015-01-01

    Although the consequences of cotyledon removal have been widely studied in oaks producing large acorns, we have little knowledge of at what level cotyledons can be removed without affecting acorn survival and seedling development. In this study, we aimed to test the hypothesis that the amount of energy reserves in cotyledons is more than the demands of seedlings and that large acorns can tolerate seed predation and/or attract seed predators for seed dispersal. Acorn germination rates were not affected even when 60% of cotyledons were cut off at the basal end, suggesting that the energy reserves contained in cotyledons are not essential for acorn survival. Post-cut acorn mass, more than initial acorn mass, appear to be a better predictor of seedling performance, indicating that the energy reserves in cotyledons are sufficient for seedlings. Acorns with large masses sustained cotyledon damage better than small ones with respect to seedling performance. Large acorns were more likely to be dispersed and cached by animals, implying that producing large acorns is more important for oaks to manipulate seed predators and dispersers rather than provide a seedling with cotyledonary reserves. PMID:25630843

  11. Acorn cotyledons are larger than their seedlings' need: evidence from artificial cutting experiments.

    PubMed

    Yi, Xianfeng; Wang, Zhenyu; Liu, Changqu; Liu, Guoqiang; Zhang, Mingming

    2015-01-01

    Although the consequences of cotyledon removal have been widely studied in oaks producing large acorns, we have little knowledge of at what level cotyledons can be removed without affecting acorn survival and seedling development. In this study, we aimed to test the hypothesis that the amount of energy reserves in cotyledons is more than the demands of seedlings and that large acorns can tolerate seed predation and/or attract seed predators for seed dispersal. Acorn germination rates were not affected even when 60% of cotyledons were cut off at the basal end, suggesting that the energy reserves contained in cotyledons are not essential for acorn survival. Post-cut acorn mass, more than initial acorn mass, appear to be a better predictor of seedling performance, indicating that the energy reserves in cotyledons are sufficient for seedlings. Acorns with large masses sustained cotyledon damage better than small ones with respect to seedling performance. Large acorns were more likely to be dispersed and cached by animals, implying that producing large acorns is more important for oaks to manipulate seed predators and dispersers rather than provide a seedling with cotyledonary reserves. PMID:25630843

  12. Soil pathogens and spatial patterns of seedling mortality in a temperate tree.

    PubMed

    Packer, A; Clay, K

    2000-03-16

    The Janzen-Connell hypothesis proposes that host-specific, distance- and/or density-dependent predators and herbivores maintain high tree diversity in tropical forests. Negative feedback between plant and soil communities could be a more effective mechanism promoting species coexistence because soil pathogens can increase rapidly in the presence of their host, causing conditions unfavourable for local conspecific recruitment. Here we show that a soil pathogen leads to patterns of seedling mortality in a temperate tree (Prunus serotina) as predicted by the Janzen-Connell hypothesis. In the field, the mean distance to parent of seedling cohorts shifted away from maternal trees over a period of 3 years. Seedlings were grown in soil collected 0-5 m or 25-30 m from Prunus trees. Sterilization of soil collected beneath trees improved seedling survival relative to unsterilized soil, whereas sterilization of distant soil did not affect survival. Pythium spp., isolated from roots of dying seedlings and used to inoculate healthy seedlings, decreased survival by 65% relative to controls. Our results provide the most complete evidence that native pathogens influence tree distributions, as predicted by the Janzen-Connell hypothesis, and suggest that similar ecological mechanisms operate in tropical and temperate forests. PMID:10749209

  13. Multi-Stage Metering Mechanism for Transplanting of Vegetable Seedlings in Paper Pots

    NASA Astrophysics Data System (ADS)

    Nandede, B. M.; Raheman, H.

    2015-09-01

    A multi-stage rotating cup type metering mechanism was developed for transplanting of vegetable seedlings of tomato, brinjal and chili raised in paper pots. The developed setup consisted of a seedling feeding wheel, metering wheel, fixed slotted plate, seedling delivery tube, furrow opener, furrow closer and a power transmission system. Its evaluation was carried out with pot seedlings of tomato, brinjal and chili of 8-11 cm height at five forward speeds (0.6, 0.9, 1.2, 2.2 and 3.2 km/h) and two plant spacings (45 and 60 cm) in controlled soil bin condition. The mean values of feeding efficiency, conveying efficiency, planting efficiency and overall efficiency of the multistage metering unit were observed to be higher than 90 % for forward speeds of 0.6 to 2.2 km/h. With further increase in speed to 3.2 km/h, the feeding and conveying efficiency were observed to be higher than 90 %, whereas, the planting efficiency drastically reduced to around 50 % due to the problem in getting the pot seedlings vertically in the furrow. Also the seedlings were falling into the furrow at an angle greater than 70 to the vertical, hence not suitable for transplanting.

  14. A spaceflight experiment for the study of gravimorphogenesis and hydrotropism in cucumber seedlings.

    PubMed

    Takahashi, H; Mizuno, H; Kamada, M; Fujii, N; Higashitani, A; Kamigaichi, S; Aizawa, S; Mukai, C; Shimazu, T; Fukui, K; Yamashita, M

    1999-12-01

    Seedlings of Cucurbitaceae plants form a protuberance, termed peg, on the transition zone between hypocotyl and root. Our spaceflight experiment verified that the lateral positioning of a peg in cucumber seedlings is modified by gravity. It has been suggested that auxin plays an important role in the gravity controlled positioning of a peg on the ground. Furthermore, cucumber seedlings grown in microgravity developed a number of the lateral roots that grew towards the water containing substrate in the culture vessel, whereas on the ground they oriented perpendicular to the primary root growing down. The response of the lateral roots in microgravity was successfully mimicked by clinorotation of cucumber seedlings on the three dimensional clinostat. However, this bending response of the lateral roots was observed only in an aeroponic culture of the seedlings but not in solid medium. We considered the response of the lateral roots in microgravity and on clinostat as positive hydrotropism that could easily be interfered by gravitropism on the ground. This system with cucumber seedlings is thus a useful model of spaceflight experiment for the study of the gravimorphogenesis, root hydrotropism and their interaction. PMID:11543179

  15. Long-distance dispersal helps germinating mahogany seedlings escape defoliation by a specialist caterpillar.

    PubMed

    Norghauer, Julian M; Grogan, James; Malcolm, Jay R; Felfili, Jeanine M

    2010-02-01

    Herbivores and pathogens with acute host specificity may promote high tree diversity in tropical forests by causing distance- and density-dependent mortality of seedlings, but evidence is scarce. Although Lepidoptera larvae are the most abundant and host-specific guild of herbivores in these forests, their impact upon seedling distributions remains largely unknown. A firm test of the mechanism underpinning the Janzen-Connell hypothesis is difficult, even for a single tree species, because it requires more than just manipulating seeds and seedlings and recording their fates. Experimental tests require: (1) an insect herbivore that is identified and highly specialised, (2) linkage to an in situ measure (or prevention) of herbivory, and (3) evaluation and confirmation among many conspecific adult trees across years. Here we present experimental evidence for a spatially explicit interaction between newly germinating seedlings of a Neotropical emergent tree, big-leaf mahogany (Swietenia macrophylla, Meliaceae), and caterpillars of a noctuid moth (Steniscadia poliophaea). In the understory of a southeastern Amazon forest, the proportion of attacks, leaf area lost, and seedling mortality due to this specialised herbivore peaked near Swietenia trees, but declined significantly with increasing distance from mature fruiting trees, as predicted by the Janzen-Connell hypothesis. We conclude that long-distance dispersal events (>50 m) provided an early survival advantage for Swietenia seedlings, and propose that the role of larval Lepidoptera as Janzen-Connell vectors may be underappreciated in tropical forests. PMID:19885680

  16. Growth and photosynthetic responses of ectomycorrhizal pine seedlings exposed to elevated Cu in soils.

    PubMed

    Chen, Yahua; Nara, Kazuhide; Wen, Zhugui; Shi, Liang; Xia, Yan; Shen, Zhenguo; Lian, Chunlan

    2015-10-01

    It is still controversial whether ectomycorrhizal (ECM) mycelia filter out toxic metals in nutrient absorption of host trees. In this study, pine (Pinus densiflora) seedlings colonized by Cu-sensitive and Cu-tolerant ECM species were exposed to a wide spectrum of soil Cu concentrations to investigate functions of ECM fungi under Cu stress. The photosynthetic rates of intact needles were monitored in situ periodically. The biomass and elements of plants were also measured after harvest. The ameliorating effect of ECM infection on host plants exposed to toxic stress was metal concentration specific. Under lower-level Cu stress, ECM fungi increased seedling performance, while ECM seedlings accumulated more Cu than nonmycorrhizal (NM) seedlings. Under higher-level Cu stress, photosynthesis decreased well before visible symptoms of Cu toxicity appeared. The reduced photosynthesis and biomass in ECM seedlings compared to NM seedlings under higher Cu conditions were also accompanied by lower phosphorus in needles. There was no marked difference between the two fungal species. Our results indicate that the two ECM fungi studied in our system may not have an ability to selectively eliminate Cu in nutrient absorption and may not act as effective barriers that decrease toxic metal uptake into host plants. PMID:25720735

  17. [Coupling effects of water and fertilizer on the biomass of Populus tomentosa seedlings].

    PubMed

    Dong, Wen-yi; Zhao, Yan; Zhang, Zhi-yi; Li, Ji-yue; Nie, Li-shui

    2010-09-01

    Water and fertilizer are the two main factors promoting the fast growth and high-yielding of Populus tomentosa, and thus, to study their coupling effects on the biomass of P. tomentosa seedlings has important practical significance. Taking the P. tomentosa clone 87 seedlings as test materials, a pot experiment with rotary combination design of square regression of three factors with five levels was conducted in the nursery of Beijing Forestry University from March to October 2008 to study the coupling effects of water, fertilizer N, and fertilizer P on the biomass of the seedlings, and a related regressive mathematical model was established. The results showed that water was the main factor affecting the biomass of P. tomentosa seedlings, followed by fertilizer N, and fertilizer P. With the increasing input of the three factors, the biomass of the seedlings increased, but when the input was beyond a certain level, the biomass began to decrease. There was a significant positive interactive effect between water and fertilizer N, but a less interactive effect between fertilizer N and fertilizer P and between water and fertilizer P. In our case, the optimal combination of water and fertilizer was 73.37% of field capacity + 4.14 g x plant(-1) of N fertilization + 1.41 g x plant(-1) of P fertilization, under which, the biomass of P. tomentosa seedlings achieved 68.30 g x plant(-1). PMID:21265137

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

    NASA Astrophysics Data System (ADS)

    Qiongying, Liu; Yanhua, Kuang; Yuemei, Zheng

    1993-07-01

    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.

  19. Growth and lignification in seedlings exposed to eight days of microgravity

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  20. Growth and lignification in seedlings exposed to eight days of microgravity.

    PubMed

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

    1984-01-01

    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. PMID:11539752

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

    PubMed Central

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

    2014-01-01

    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. PMID:25083352

  2. Genetic Analysis of Gravity Signal Transduction in Arabidopsis thaliana Seedlings

    NASA Astrophysics Data System (ADS)

    Boonsirichai, K.; Harrison, B.; Stanga, J.; Young, L.-S.; Neal, C.; Sabat, G.; Murthy, N.; Harms, A.; Sedbrook, J.; Masson, P.

    The primary roots of Arabidopsis thaliana seedlings respond to gravity stimulation by developing a tip curvature that results from differential cellular elongation on opposite flanks of the elongation zone. This curvature appears modulated by a lateral gradient of auxin that originates in the gravity-perceiving cells (statocytes) of the root cap through an apparent lateral repositioning of a component the auxin efflux carrier complex within these cells (Friml et al, 2002, Nature 415: 806-809). Unfortunately, little is known about the molecular mechanisms that govern early phases of gravity perception and signal transduction within the root-cap statocytes. We have used a molecular genetic approach to uncover some of these mechanisms. Mutations in the Arabidopsis ARG1 and ARL2 genes, which encode J-domain proteins, resulted in specific alterations in root and hypocotyl gravitropism, without pleiotropic phenotypes. Interestingly, ARG1 and ARL2 appear to function in the same genetic pathway. A combination of molecular genetic, biochemical and cell-biological approaches were used to demonstrate that ARG1 functions in early phases of gravity signal transduction within the root and hypocotyl statocytes, and is needed for efficient lateral auxin transport within the cap. The ARG1 protein is associated with components of the secretory and/or endosomal pathways, suggesting its role in the recycling of components of the auxin efflux carrier complex between plasma membrane and endosome (Boonsirichai et al, 2003, Plant Cell 15:2612-2625). Genetic modifiers of arg1-2 were isolated and shown to enhance the gravitropic defect of arg1-2, while resulting in little or no gravitropic defects in a wild type ARG1 background. A slight tendency for arg1-2;mar1-1 and arg1-2;mar2-1 double-mutant organs to display an opposite gravitropic response compared to wild type suggests that all three genes contribute to the interpretation of the gravity-vector information by seedling organs. The molecular structure of these new loci is being investigated. Furthermore, a proteomic approach is being developed to characterize root-tip proteins that are differentially expressed, modified or targeted in response to gravity stimulation. We acknowledge funding by NASA and NSF.

  3. Hunting alters seedling functional trait composition in a Neotropical forest.

    PubMed

    Kurten, Erin L; Wright, S Joseph; Carson, Walter P

    2015-07-01

    Defaunation alters trophic interactions between plants and vertebrates, whichmay disrupt trophic cascades, thereby favoring a subset of plant species and reducing diversity. If particular functional traits characterize the favored plant species,.then defaunation may alter community-wide patterns of functional trait composition. Changes in plant functional traits occurring with defaunation may help identify the species interactions affected by defaunation and the potential for other cascading effects of defaunation. We tested the hypotheses that defaunation would (1) disrupt seed dispersal, thereby favoring species whose dispersal agents are not affected (e.g., small birds, bats, and abiotic agents), (2) reduce seed predation, thereby favoring larger-seeded species, and (3) reduce herbivory, thereby favoring species with lower leaf mass per area (LMA), leaf toughness, and wood density. We examined how these six traits responded to vertebrate defaunation caused by hunters or by experimental exclosures among more than-30 000 woody seedlings in a lowland tropical moist forest. Exclosures reduced terrestrial frugivores, granivores, and herbivores, while hunters also reduced volant and arboreal frugivores and granivores. The comparison of exclosures and hunting allowed us to parse the impacts of arboreal and volant species (reduced by hunters only) and terrestrial species (reduced by both hunters and exclosures). The loss of terrestrial vertebrates alone had limited effects on plant trait composition. The additional loss of volant and arboreal vertebrates caused significant shifts in plant species composition towards communities with more species dispersed abiotically, including lianas and low wood-density tree species, and fewer species dispersed by large vertebrates. In contrast to previous studies, community seed mass did not decline significantly in hunted sites. Our exclosure results suggest this is because reducing seed predators disproportionately benefits large-seeded species,.partially compensating for the reduction of seed dispersers at hunted sites. Our result9sdemonstrate that decreased seed dispersal and seed predation are important determinants of seedling community compositional change as a consequence of defaunation. Defaunation may also negatively impact carbon storage in tropical forests, by favoring lianas and low wood density tree species. PMID:26378314

  4. Quantification of jasmonic and salicylic acids in rice seedling leaves.

    PubMed

    Cho, Kyoungwon; Han, Oksoo; Tamogami, Shigeru; Shibato, Junko; Kubo, Akihiro; Agrawal, Ganesh Kumar; Rakwal, Randeep

    2013-01-01

    Jasmonic acid (JA) and salicylic acid (SA) are critical signaling components involved in various aspects of plant growth, development, and defense. Their constitutive levels vary from plant to plant and also from tissue to tissue within the same plant. Moreover, their quantitative levels change when plant is exposed to biotic and abiotic stresses. To better understand the JA- and SA-mediated signaling and metabolic pathways, it is important to precisely quantify their levels in plants/tissues/organs. However, their extraction and quantification are not trivial and still technically challenging. An effort has been made in various laboratories to develop a simple and standard procedure that can be utilized for quantification of JA and SA. Here, we present the experimental procedure and our decade of experience on extracting and quantifying them in an absolute manner in leaves of rice seedlings. We must mention that this method has been applied to both monocotyledonous and dicotyledonous plants for absolute quantification of JA and SA. As collaboration is the key towards rapid progress in science and technology, we are always open to sharing our experience in this field with any active research group with an aim to improve the procedure further and eventually to connect the importance of their (JA and SA) quantitative levels with networks of signaling and metabolic pathways in plants. PMID:23135852

  5. Effect of spaceflight on isoflavonoid accumulation in etiolated soybean seedlings

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    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.

  6. Clinorotation affects morphology and ethylene production in soybean seedlings

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

    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.

  7. Savanna Tree Seedlings are Physiologically Tolerant to Nighttime Freeze Events

    PubMed Central

    O’Keefe, Kimberly; Nippert, Jesse B.; Swemmer, Anthony M.

    2016-01-01

    Freeze events can be important disturbances in savanna ecosystems, yet the interactive effect of freezing with other environmental drivers on plant functioning is unknown. Here, we investigated physiological responses of South African tree seedlings to interactions of water availability and freezing temperatures. We grew widely distributed South African tree species (Colophospermum mopane, Combretum apiculatum, Acacia nigrescens, and Cassia abbreviata) under well-watered and water-limited conditions and exposed individuals to nighttime freeze events. Of the four species studied here, C. mopane was the most tolerant of lower water availability. However, all species were similarly tolerant to nighttime freezing and recovered within one week following the last freezing event. We also show that water limitation somewhat increased freezing tolerance in one of the species (C. mopane). Therefore, water limitation, but not freezing temperatures, may restrict the distribution of these species, although the interactions of these stressors may have species-specific impacts on plant physiology. Ultimately, we show that unique physiologies can exist among dominant species within communities and that combined stresses may play a currently unidentified role in driving the function of certain species within southern Africa. PMID:26870065

  8. Isolation and characterization of a neutral phosphatase from wheat seedlings

    SciTech Connect

    Cheng, H.F.

    1988-01-01

    A neutral phosphatase was purified to homogeneity from wheat seedlings. The enzyme was a monomeric glycoprotein exhibiting a molecular weight of 35,000, frictional ratio of 1.22, Stokes' radius of 26 A, and sedimentation coefficient of 3.2 S. That the enzyme was a glycoprotein was surmised from its chromatographic property on Concanavalin A-Sepharose column. The phosphatase activity was assayed using either fructose-2,6-bisphosphate or p-nitrophenyl phosphate as substrate. The phosphatase activity was not affected by high concentrations of chelating agents and did not require the addition of Mg{sup +2} or Ca{sup +2} for its activity. Molybdate, orthovanadate, Zn{sup +2}, and Hg{sup +2} were all potent inhibitors of the phosphatase activity. The inhibition by Hg{sup +2} was reversed by dithiothreitol. The enzyme activity was stimulated by Mn{sup +2} about 2-fold. On the other hand, 3-phosphoglycerate, fructose-6-P and Pi as well as polyamines inhibited the enzyme activity. The ability of the neutral phosphatase to dephosphorylate protein phosphotyrosine was also investigated. The phosphotyrosyl-substrates, such as ({sup 32}P) phosphotyrosyl-poly(Glu, Tyr)n, -alkylated bovine serum albumin, -angiotensin-1, and -band 3 of erythrocytes, were all substrates of the phosphatase. On the other hand, the enzyme had no activity toward protein phosphoserine and protein phosphothreonine.

  9. Savanna Tree Seedlings are Physiologically Tolerant to Nighttime Freeze Events.

    PubMed

    O'Keefe, Kimberly; Nippert, Jesse B; Swemmer, Anthony M

    2016-01-01

    Freeze events can be important disturbances in savanna ecosystems, yet the interactive effect of freezing with other environmental drivers on plant functioning is unknown. Here, we investigated physiological responses of South African tree seedlings to interactions of water availability and freezing temperatures. We grew widely distributed South African tree species (Colophospermum mopane, Combretum apiculatum, Acacia nigrescens, and Cassia abbreviata) under well-watered and water-limited conditions and exposed individuals to nighttime freeze events. Of the four species studied here, C. mopane was the most tolerant of lower water availability. However, all species were similarly tolerant to nighttime freezing and recovered within one week following the last freezing event. We also show that water limitation somewhat increased freezing tolerance in one of the species (C. mopane). Therefore, water limitation, but not freezing temperatures, may restrict the distribution of these species, although the interactions of these stressors may have species-specific impacts on plant physiology. Ultimately, we show that unique physiologies can exist among dominant species within communities and that combined stresses may play a currently unidentified role in driving the function of certain species within southern Africa. PMID:26870065

  10. Characterization of nucleases involved in seedling development of cauliflower.

    PubMed

    Le?niewicz, Krzysztof; Pie?kowska, Joanna; Poreba, Elzbieta

    2010-09-01

    The ability of cells to control the degradation of their own DNA is a common feature of most living organisms. In plants, extensive hydrolysis of nuclear DNA occurs during different forms of programmed cell death (PCD). In addition to the removal of unwanted cells, the PCD process allows for the remobilization of cellular constituents, including the products of DNA hydrolysis. Although programmed cell death occurs widely during normal development and plant defense responses to pathogens, only one class of deoxyribonucleases, the S1 type, involved in these processes, has been well characterized. Using DNA-SDS-PAGE, we identified the activities of 14 deoxyribonucleases expressed in different organs of cauliflower seeds, seedlings and the flower head. These enzymes represent several classes based on their substrate specificity and ion dependency. In addition to four Zn(2+)-dependent enzymes, we identified five Ca(2+)-dependent, two Mg(2+)-dependent, three Ca(2+)/Mg(2+)-dependent and one nuclease whose activities seem to be independent of any divalent cations. We also identified a set of DNases whose expression seems to be common for different organs and different stages of development, as well as a few highly tissue-specific nucleases. Expression of three nucleases was inducible by drought stress and hydrogen peroxide. PMID:20447722

  11. Effects of Gamma and electron beam Irradiation on wheat seedlings

    NASA Astrophysics Data System (ADS)

    Singh, Sandhya; Jagtap, Sagar; Vidyasagar, Pandit; Dhole, Sanjay

    2012-07-01

    Understanding plant behavior in space is very significant as not only they provide nourishment and functioning of life support systems in manned space missions but they also help the astronauts to tolerate isolated conditions from earth. As space environment is comprised of different types of ionizing and non-ionizing radiations such as protons, electrons, heavy ions, alpha and gamma rays. It is necessary to study the effects of these radiations on plants. Experiments were carried out to determine the effects of gamma radiation and electron beam separately on germination and physiological characteristics of wheat seedlings. A wheat genotype (Lokvan) seeds were pre-soaked for 22 hrs and irradiated with 100, 150, 200, 250, 300 Gy of gamma radiation. The results obtained showed that root and shoot length, as well as chlorophyll content decreased with increasing radiation dose however seed germination percentage was not significantly affected by radiation dose. Similar effects were observed in pre-soaked wheat seeds irradiated by electron beam using microtron accelerator with 300, 600, 900, 1200 Gy dose. Further studies on radiation coupled with altered gravity (microgravity and hypergravity) are being planned to be carried out. Effects of radiation and altered gravity on proline content, fluorescence, and photosynthetic activity will also be studied.

  12. Physiological responses of fenugreek seedlings and plants treated with cadmium.

    PubMed

    Zayneb, Chabene; Bassem, Khemakhem; Zeineb, Kamoun; Grubb, C Douglas; Noureddine, Drira; Hafedh, Mejdoub; Amine, Elleuch

    2015-07-01

    The bioaccumulation efficiency of cadmium (Cd) by fenugreek (Trigonella foenum-graecum) was examined using different concentrations of CdCl2. The germination rate was similar to control except at 10 mM Cd. However, early seedling growth was quite sensitive to the metal from the lowest Cd level. Accordingly, amylase activity was reduced substantially on treatment of seeds with 0.5, 1, and 10 mM Cd. Cadmium also affected various other plant growth parameters. Its accumulation was markedly lower in shoots as compared to roots, reducing root biomass by almost 50 %. Plants treated with 1 and 5 mM Cd presented chlorosis due to a significant reduction in chlorophyll b especially. Furthermore, at Cd concentrations greater than 0.1 mM, plants showed several signs of oxidative stress; an enhancement in root hydrogen peroxide (H2O2) level and in shoot malondialdehyde (MDA) content was observed. Conversely, antioxidant enzyme activities (superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT)) increased in various plant parts. Likewise, total phenolic and flavonoid contents reached their highest values in the 0.5 mM Cd treatment, consistent with their roles in quenching low concentrations of reactive oxygen species (ROS). Consequently, maintaining oxidant and antioxidant balance may permit fenugreek to hyperaccumulate Cd and allow it to be employed in extremely Cd polluted soils for detoxification purposes. PMID:25752634

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

    PubMed

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

    2013-08-01

    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

  14. Polyamines in rice seedlings under oxygen-deficit stress

    SciTech Connect

    Reggiani, R.; Hochkoeppler, A.; Bertani, A. )

    1989-11-01

    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.

  15. Tocopherols in Sunflower Seedlings under Light and Dark Conditions

    PubMed Central

    del Moral, Lidia; Pérez-Vich, Begoña; Velasco, Leonardo

    2015-01-01

    The objective of this study was to evaluate the dynamics of tocopherols in cotyledons and radicles from sunflower seeds with high and low total tocopherol content, mainly in the α-tocopherol form, and from seeds with increased proportions of β-, γ-, and δ-tocopherol, both under dark and light conditions. Tocopherol content was measured every 24 h from 1 to 12 days after sowing. In all cases, the content of individual tocopherol forms in the cotyledons and radicles was reduced along the sampling period, which was more pronounced under light conditions. The presence of light had a slightly greater effect on α- and γ-tocopherol than on β- and δ-tocopherol. A marked light effect was also observed on total tocopherol content, with light promoting the reduction of tocopherol content in cotyledons and radicles. The study revealed only slight differences in the patterns of tocopherol losses in lines with different tocopherol profiles, both under dark and light conditions, which suggested that the partial replacement of α-tocopherol by other tocopherol forms had no great impact on the protection against oxidative damage in seedlings. PMID:26347898

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

    PubMed Central

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

    2012-01-01

    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

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

    PubMed

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

    2012-01-01

    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

  18. Variation in experimental flood impacts and ecogeomorphic feedbacks among native and exotic riparian tree seedlings

    NASA Astrophysics Data System (ADS)

    Kui, L.; Stella, J. C.; Skorko, K.; Lightbody, A.; Wilcox, A. C.; Bywater-Reyes, S.

    2012-12-01

    Flooding interacts with riparian plants on a variety of scales, resulting in coevolution of geomorphic surfaces with plant vegetation communities. Our research aims to develop a mechanistic understanding of riparian seedling damage from small floods, with a focus on differential responses among species (native and non-native), ecogeomorphic feedbacks, and implications for riparian restoration. We tested the effects of controlled flood events on cottonwood (Populus fremontii) and tamarisk (Tamarix spp.) seedlings in an experimental meandering stream channel. We hypothesized that seedling dislodgement and burial would be influenced by individual plant height, species-specific morphology, patch density, and differences in hydraulic forces (as a function of location on the bar). Four experimental floods were tested, with different combinations of plant species and seedling densities. For each flood run, rooted seedlings were installed within a 1.5-m-wide sandbar during low flow conditions and stream discharge was increased to a constant flood level for approximately 8 hours, after which seedling response was assessed. Seedling damage was analyzed within a logistic regression framework that predicted the probability of dislodgement or burial as a function of the explanatory variables. Plant dislodgement depended on root length and the location on the sandbar, whereas burial depended on plant height, species-specific morphology, and location. For every centimeter increase in plant height, the odds of plant burial decreased by 10 percent, illustrating the rate at which plants developed flood resistance as they grow taller. With every meter closer to the thalweg, plant dislodgement was four times more likely, and plant burial was 2.6 times more likely. The probability of burial was twice as great for tamarisk seedlings as for cottonwood. The increased sedimentation within tamarisk patches was associated with a denser foliage and a more compact crown for this species. The crown center of mass was 8.5 cm above the bed on average for tamarisk seedlings, versus 18 cm above the bed for cottonwood. These results suggest that both environmental variables and plant morphological traits are important to consider when designing flow-based restoration efforts on regulated rivers. For example, we expect that few plants are dislodged during small floods and that tamarisk are more likely to be buried compared to cottonwood.Fig. 1. Probability of seedling burial for tamarisk (left) is greater than for cottonwood independent of plant height and distance to the thalweg.

  19. Urban environment of New York City promotes growth in northern red oak seedlings.

    PubMed

    Searle, Stephanie Y; Turnbull, Matthew H; Boelman, Natalie T; Schuster, William S F; Yakir, Dan; Griffin, Kevin L

    2012-04-01

    Urbanization is accelerating across the globe, elevating the importance of studying urban ecology. Urban environments exhibit several factors affecting plant growth and function, including high temperatures (particularly at night), CO(2) concentrations and atmospheric nitrogen deposition. We investigated the effects of urban environments on growth in Quercus rubra L. seedlings. We grew seedlings from acorns for one season at four sites along an urban-rural transect from Central Park in New York City to the Catskill Mountains in upstate New York (difference in average maximum temperatures of 2.4 °C; difference in minimum temperatures of 4.6 °C). In addition, we grew Q. rubra seedlings in growth cabinets (GCs) mimicking the seasonal differential between the city and rural sites (based on a 5-year average). In the field experiment, we found an eightfold increase in biomass in urban-grown seedlings relative to those grown at rural sites. This difference was primarily related to changes in growth allocation. Urban-grown seedlings and seedlings grown at urban temperatures in the GCs exhibited a lower root: shoot ratio (urban ~0.8, rural/remote ~1.5), reducing below-ground carbon costs associated with construction and maintenance. These urban seedlings instead allocated more growth to leaves than did rural-grown seedlings, resulting in 10-fold greater photosynthetic area but no difference in photosynthetic capacity of foliage per unit area. Seedlings grown at urban temperatures in both the field and GC experiments had higher leaf nitrogen concentrations per unit area than those grown at cooler temperatures (increases of 23% in field, 32% in GC). Lastly, we measured threefold greater (13)C enrichment of respired CO(2) (relative to substrate) in urban-grown leaves than at other sites, which may suggest greater allocation of respiratory function to growth over maintenance. It also shows that lack of differences in total R flux in response to environmental conditions may mask dramatic shifts in respiratory functioning. Overall, our findings indicating greater seedling growth and establishment at a critical regeneration phase of forest development may have important implications for the ecology of urban forests as well as the predicted growth of the terrestrial biosphere in temperate regions in response to climate change. PMID:22491523

  20. Two novel techniques to screen Abies seedlings for resistance to the balsam woolly adelgid, Adelges piceae.

    PubMed

    Newton, Leslie; Frampton, John; Monahan, John; Goldfarb, Barry; Hain, Fred

    2011-01-01

    Since its introduction into the Southern Appalachians in the 1950s, the balsam woolly adelgid, Adelges piceae Ratzeburg (Hemiptera: Adelgidae), has devastated native populations of Fraser fir, Abies fraseri (Pursh) Poir. (Pinales: Pinaceae), and has become a major pest in Christmas tree plantations requiring expensive chemical treatments. Adelges piceae-resistant Fraser fir trees would lessen costs for the Christmas tree industry and assist in the restoration of native stands. Resistance screening is an important step in this process. Here, four studies directed toward the development of time- and cost-efficient techniques for screening are reported. In the first study, three methods to artificially infest seedlings of different ages were evaluated in a shade-covered greenhouse. Two-year-old seedlings had much lower infestation levels than 7 year-old seedlings. Placing infested bark at the base of the seedling was less effective than tying infested bark to the seedling or suspending infested bolts above the seedling. Although the two latter techniques resulted in similar densities on the seedlings, they each have positive and negative considerations. Attaching bark to uninfested trees is effective, but very time consuming. The suspended bolt method mimics natural infestation and is more economical than attaching bark, but care must be taken to ensure an even distribution of crawlers falling onto the seedlings. The second study focused on the density and distribution of crawlers falling from suspended bolts onto paper gridded into 7.6 7.6 cm cells. Crawler density in a 30 cm band under and to each side of the suspended bolt ranged from 400 to over 3000 crawlers per cell (1 to 55 crawlers per cm). In the third study, excised branches from 4 year-old A. fraseri and A. vetchii seedlings were artificially infested with A. piceae to determine whether this technique may be useful for early resistance screening. The excised A. fraseri branches supported complete adelgid development (crawler to egg-laying adult), and very little adelgid development occurred on A. vetchii branches. The fourth study compared infestation levels and gouting response on excised versus intact branches of 4 year-old A. fraseri seedlings from three different seed sources, and excised branches from 4 year-old and 25 year-old trees. There were no differences in infestation levels between excised versus intact branches nor in very young versus mature trees; gouting response was observed only on intact branches. PMID:22239164

  1. Seedling establishment at the alpine tree line - Can there be too much winter protection?

    NASA Astrophysics Data System (ADS)

    Lett, S.; Wardle, D.; Nilsson, M. C.; Dorrepaal, E.

    2014-12-01

    Alpine and arctic tree line expansion relies on tree seedling survival above the tree line, where the environment is harsh and protection by snow during winter is essential. Above the tree line, bryophytes are dominant; they may act as thermal insulators but their insulating ability differs between species. Apart from these positive effects, both snow and bryophytes may have negative effects on seedlings via shortening of the growing season or competition, respectively. Snow depth and duration are expected to change due to climate change, leading in some places to more snow and in others to less. What is the role of bryophytes insulating properties for seedling establishment under changing winter conditions at the alpine tree line? We hypothesized that protecting effects of snow and bryophytes would be more important for seedling survival in harsh climate (high elevation) than in milder climate (low elevation) (interactions: bryophyte*elevation and snow*elevation) and that negative effects of less snow would be ameliorated by well-insulating bryophytes (interaction: bryophyte*snow). To test this, we transplanted cores of three bryophyte species of differing insulation capacity and bare soil (control) from the subarctic tree line (~600m asl.) to 700 and 350 m asl. We transplanted 10 seedlings of two common tree line tree species (Betula pubescens and Pinus sylvestris) into each core in late summer. Cores were subjected to one of three snow treatments: autumn and spring snow removal or addition, or no manipulation. After the winter we scored seedling survival. The snow treatments had different effects at the two elevations (elevation* snow: P<0.0001) whereas bryophytes did not (elevation*bryophyte: n.s). In the harsh climate, snow addition generally enhanced seedling survival. In contrast, at the milder climate site, snow addition only increased survival in the bare soil treatment but decreased survival of seedlings in the bryophyte cores (bryophyte*snow: P=0.053). Our data show that snow cover is the dominant, positive control on winter survival of tree seedlings above the current tree line, irrespective of the bryophyte cover. In a milder climate, however, the role of snow cover depends on the bryophyte cover, with negative effects of extra snow on seedling survival in the presence of bryophytes and vice versa.

  2. Two Novel Techniques to Screen Abies Seedlings for Resistance to the Balsam Woolly Adelgid, Adelges piceae

    PubMed Central

    Newton, Leslie; Frampton, John; Monahan, John; Goldfarb, Barry; Hain, Fred

    2011-01-01

    Since its introduction into the Southern Appalachians in the 1950s, the balsam woolly adelgid, Adelges piceae Ratzeburg (Hemiptera: Adelgidae), has devastated native populations of Fraser fir, Abies fraseri (Pursh) Poir. (Pinales: Pinaceae), and has become a major pest in Christmas tree plantations requiring expensive chemical treatments. Adelges piceae—resistant Fraser fir trees would lessen costs for the Christmas tree industry and assist in the restoration of native stands. Resistance screening is an important step in this process. Here, four studies directed toward the development of time— and cost—efficient techniques for screening are reported. In the first study, three methods to artificially infest seedlings of different ages were evaluated in a shade—covered greenhouse. Two—year—old seedlings had much lower infestation levels than 7 year—old seedlings. Placing infested bark at the base of the seedling was less effective than tying infested bark to the seedling or suspending infested bolts above the seedling. Although the two latter techniques resulted in similar densities on the seedlings, they each have positive and negative considerations. Attaching bark to uninfested trees is effective, but very time consuming. The suspended bolt method mimics natural infestation and is more economical than attaching bark, but care must be taken to ensure an even distribution of crawlers falling onto the seedlings. The second study focused on the density and distribution of crawlers falling from suspended bolts onto paper gridded into 7.6 × 7.6 cm cells. Crawler density in a 30 cm band under and to each side of the suspended bolt ranged from 400 to over 3000 crawlers per cell (1 to 55 crawlers per cm2). In the third study, excised branches from 4 year—old A. fraseri and A. vetchii seedlings were artificially infested with A. piceae to determine whether this technique may be useful for early resistance screening. The excised A. fraseri branches supported complete adelgid development (crawler to egg—laying adult), and very little adelgid development occurred on A. vetchii branches. The fourth study compared infestation levels and gouting response on excised versus intact branches of 4 year—old A. fraseri seedlings from three different seed sources, and excised branches from 4 year—old and 25 year—old trees. There were no differences in infestation levels between excised versus intact branches nor in very young versus mature trees; gouting response was observed only on intact branches. PMID:22239164

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

    PubMed

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

    2007-12-01

    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

  4. Light Affects the Chloroplast Ultrastructure and Post-Storage Photosynthetic Performance of Watermelon (Citrullus lanatus) Plug Seedlings

    PubMed Central

    Duan, Qingqing; Jiang, Wu; Ding, Ming; Lin, Ye; Huang, Danfeng

    2014-01-01

    Watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] plug seedlings were stored at 15C in the light at a photosynthetic photon flux density of 15 molm?2s?1 or in darkness for 6 days, to evaluate their chloroplast ultrastructure, and associated photosynthetic characteristics. Storage in the dark caused swelling, disordered granal arrangement, and starch grain disappearance in the chloroplasts. In contrast, the chloroplasts stored in the light were relatively normal. As a result, the light-stored seedlings had a significantly higher chlorophyll content, Fv/Fm, and Pn than did dark-stored seedlings. Regardless of whether the seedlings were stored in light or darkness, the Gs and Ls of the seedlings significantly decreased, while the Ci obviously increased when the Pn decreased after 6 days of storage. This result suggests that the decreased Pn is not solely a stomatal effect, as the effects on the chloroplasts contributed to this photosynthetic inhibition. Six days after transplanting, seedlings that were stored in the light or darkness for 2 or 4 days showed complete recovery of chloroplast ultrastructure, chlorophyll content, Fv/Fm, Gs and Pn. When the storage period increased to 6 days, the dark-stored seedlings had a significantly lower Fv/Fm and Pn than the light-stored and control seedlings 6 days after transplanting, which was mainly ascribed to incomplete recovery of chloroplast ultrastructure. Furthermore, the light-stored seedlings exhibited a significantly higher shoot dry weight during storage and a higher percentage dry weight increase after transplanting than the dark-stored seedlings. These effects were enhanced by prolonged storage (4 to 6 days). This study demonstrated that dim light during storage is beneficial for maintaining chloroplast ultrastructure as well as photosynthetic efficiency in watermelon seedlings, thus contributing to the rapid recovery of post-storage photosynthetic performance, which ensures the transplant quality of the seedlings after removal from storage. PMID:25340859

  5. Effect of co-inoculations of native PGPR with nitrogen fixing bacteria on seedling traits in Prosopis cineraria.

    PubMed

    Singh, S K; Pancholy, Anjly; Jindal, S K; Pathak, Rakesh

    2014-09-01

    Prosopis cineraria significantly contribute to sand dune stabilization, soil fertility rejuvenation and is an integral component of agro-forestry systems in arid regions of India. Effect of different rhizobacterial seed treatments on seed germination and seedling traits in two genotypes of P. cineraria (HPY-1) and (FG-1) were tested. Observations on seed germination (%) and seedling traits viz., root length (cm), shoot length (cm), seedling weight (g) and seedling length of different treatments were recorded. Whereas, germination index (GI), seedling vigour index (SVI) and root/shoot length ratio were derived from the observed data. The scarification treatment with sulphuric acid for 10 minutes substantially enhanced germination from < 20% to 80-82% in control treatments. Treatments with co-inoculations of Bacillus licheniformis and Sinorhizobium kostiense or S. saheli supported the maximum seed germination and seedling growth and vigour. The maximum germination per cent (92.5%), seedling length (10.94 cm), seedling vigour index (10.12) and germination index (7.97) were recorded with treatment (V2T6) wherein seeds of high pod yielding genotype were co-inoculated with Bacillus licheniformis and S. kostiense. The higher positive correlations of seedling length v/s shoot length followed by SVI v/s seedling length, SVI v/s root length and seedling length v/s root length is a fair indicative of inter dependency of these characteristics. Higher R2 values of root length v/s shoot length followed by that of SVI v/s GI indicates that a regression line fits the data well and future outcomes of observed seedling traits are likely to be predicted by the model. PMID:25204069

  6. Light affects the chloroplast ultrastructure and post-storage photosynthetic performance of watermelon (Citrullus lanatus) plug seedlings.

    PubMed

    Duan, Qingqing; Jiang, Wu; Ding, Ming; Lin, Ye; Huang, Danfeng

    2014-01-01

    Watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] plug seedlings were stored at 15C in the light at a photosynthetic photon flux density of 15 molm(-2)s(-1) or in darkness for 6 days, to evaluate their chloroplast ultrastructure, and associated photosynthetic characteristics. Storage in the dark caused swelling, disordered granal arrangement, and starch grain disappearance in the chloroplasts. In contrast, the chloroplasts stored in the light were relatively normal. As a result, the light-stored seedlings had a significantly higher chlorophyll content, Fv/Fm, and Pn than did dark-stored seedlings. Regardless of whether the seedlings were stored in light or darkness, the Gs and Ls of the seedlings significantly decreased, while the Ci obviously increased when the Pn decreased after 6 days of storage. This result suggests that the decreased Pn is not solely a stomatal effect, as the effects on the chloroplasts contributed to this photosynthetic inhibition. Six days after transplanting, seedlings that were stored in the light or darkness for 2 or 4 days showed complete recovery of chloroplast ultrastructure, chlorophyll content, Fv/Fm, Gs and Pn. When the storage period increased to 6 days, the dark-stored seedlings had a significantly lower Fv/Fm and Pn than the light-stored and control seedlings 6 days after transplanting, which was mainly ascribed to incomplete recovery of chloroplast ultrastructure. Furthermore, the light-stored seedlings exhibited a significantly higher shoot dry weight during storage and a higher percentage dry weight increase after transplanting than the dark-stored seedlings. These effects were enhanced by prolonged storage (4 to 6 days). This study demonstrated that dim light during storage is beneficial for maintaining chloroplast ultrastructure as well as photosynthetic efficiency in watermelon seedlings, thus contributing to the rapid recovery of post-storage photosynthetic performance, which ensures the transplant quality of the seedlings after removal from storage. PMID:25340859

  7. The effects of methyl bromide alternatives on soil and seedling microbial populations, weeds, and seedling morphology in Oregon and Washington forest tree nurseries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Six fumigant treatments were evaluated at two forest tree nurseries in Oregon and one forest tree nursery in Washington for their effects on soil microbial populations, weeds, and seedling morphology during a 2-year study. Fusarium commune, F. oxysporum, Gibberella fujikuroi complex, P. irregulare,...

  8. Sensitivity of cold acclimation to elevated autumn temperature in field-grown Pinus strobus seedlings

    PubMed Central

    Chang, Christine Y.; Unda, Faride; Zubilewich, Alexandra; Mansfield, Shawn D.; Ensminger, Ingo

    2015-01-01

    Climate change will increase autumn air temperature, while photoperiod decrease will remain unaffected. We assessed the effect of increased autumn air temperature on timing and development of cold acclimation and freezing resistance in Eastern white pine (EWP, Pinus strobus) under field conditions. For this purpose we simulated projected warmer temperatures for southern Ontario in a Temperature Free-Air-Controlled Enhancement (T-FACE) experiment and exposed EWP seedlings to ambient (Control) or elevated temperature (ET, +1.5°C/+3°C during day/night). Photosynthetic gas exchange, chlorophyll fluorescence, photoprotective pigments, leaf non-structural carbohydrates (NSC), and cold hardiness were assessed over two consecutive autumns. Nighttime temperature below 10°C and photoperiod below 12 h initiated downregulation of assimilation in both treatments. When temperature further decreased to 0°C and photoperiod became shorter than 10 h, downregulation of the light reactions and upregulation of photoprotective mechanisms occurred in both treatments. While ET seedlings did not delay the timing of the downregulation of assimilation, stomatal conductance in ET seedlings was decreased by 20–30% between August and early October. In both treatments leaf NSC composition changed considerably during autumn but differences between Control and ET seedlings were not significant. Similarly, development of freezing resistance was induced by exposure to low temperature during autumn, but the timing was not delayed in ET seedlings compared to Control seedlings. Our results indicate that EWP is most sensitive to temperature changes during October and November when downregulation of photosynthesis, enhancement of photoprotection, synthesis of cold-associated NSCs and development of freezing resistance occur. However, we also conclude that the timing of the development of freezing resistance in EWP seedlings is not affected by moderate temperature increases used in our field experiments. PMID:25852717

  9. Salinity and light interactively affect neotropical mangrove seedlings at the leaf and whole plant levels.

    PubMed

    Lpez-Hoffman, Laura; Anten, Niels P R; Martnez-Ramos, Miguel; Ackerly, David D

    2007-01-01

    We have studied the interactive effects of salinity and light on Avicennia germinans mangrove seedlings in greenhouse and field experiments. We hypothesized that net photosynthesis, growth, and survivorship rates should increase more with an increase in light availability for plants growing at low salinity than for those growing at high salinity. This hypothesis was supported by our results for net photosynthesis and growth. Net daily photosynthesis did increase more with increasing light for low-salinity plants than for high-salinity plants. Stomatal conductance, leaf-level transpiration, and internal CO(2) concentrations were lower at high than at low salinity. At high light, the ratio of leaf respiration to assimilation was 2.5 times greater at high than at low salinity. Stomatal limitations and increased respiratory costs may explain why, at high salinity, seedlings did not respond to increased light availability with increased net photosynthesis. Seedling mass and growth rates increased more with increasing light availability at low than at high salinity. Ratios of root mass to leaf mass were higher at high salinity, suggesting that either water or nutrient limitations may have limited seedling growth at high salinity in response to increasing light. The interactive effects of salinity and light on seedling size and growth rates observed in the greenhouse were robust in the field, despite the presence of other factors in the field--such as inundation, nutrient gradients, and herbivory. In the field, seedling survivorship was higher at low than at high salinity and increased with light availability. Interestingly, the positive effect of light on seedling survivorship was stronger at high salinity, indicating that growth and survivorship rates are decoupled. In general, this study demonstrates that environmental effects at the leaf-level also influence whole plant growth in mangroves. PMID:17024379

  10. A comparative study of oak (Quercus, Fagaceae) seedling physiology during summer drought in southern California.

    PubMed

    Mahall, Bruce E; Tyler, Claudia M; Cole, E Shelly; Mata, Catarina

    2009-04-01

    Natural recruitment of oaks appears to be declining throughout the northern hemisphere. Summer drought poses a potentially important barrier to oak recruitment in southern California. To evaluate this barrier, we grew evergreen Quercus agrifolia and deciduous Q. lobata from seeds near parental trees. We measured water relations, chlorophyll fluorescence, and gas exchange during these seedlings' fourth and fifth summers and compared them to neighboring adults. Most seedlings had substantially lower values for predawn xylem pressure potential (?(pd)), minimum photosystem II (PSII) quantum efficiency (?(PSIIMIN)), maximum quantum efficiency for PSII under dark-adapted leaf conditions (Fv/Fm), and maximum photosynthetic assimilation (Amax), and higher values for maximum nonphotochemical quenching (NPQmax) than did conspecific adults. The high, unvarying ?(pd) values of the adults suggest they use perennially available groundwater. Quercus lobata seedlings commonly had lower values for ?(pd) than did Q. agrifolia, and values for ?(pd) and ?(PSIIMIN) were significantly related to size in Q. lobata but not in Q. agrifolia. These data suggest important interspecific differences in root architecture. Lower values for ?(PSIIMIN), Fv/Fm, and higher NPQmax in Q. agrifolia indicate that Q. agrifolia seedlings were usually under more stress than Q. lobata, which typically had higher Amax rates than did Q. agrifolia seedlings. Diurnal photosynthesis curves were quite flat for Q. agrifolia, but they peaked in the morning for Q. lobata. Established seedlings appeared to be under more stress than adults, but this stress did not appear severe enough to cause death. Access to perennially available groundwater may be crucial for the seedling to sapling transition. PMID:21628230

  11. Fertility-dependent effects of ectomycorrhizal fungal communities on white spruce seedling nutrition.

    PubMed

    Smith, Alistair J H; Potvin, Lynette R; Lilleskov, Erik A

    2015-11-01

    Ectomycorrhizal fungi (EcMF) typically colonize nursery seedlings, but nutritional and growth effects of these communities are only partly understood. To examine these effects, Picea glauca seedlings collected from a tree nursery naturally colonized by three dominant EcMF were divided between fertilized and unfertilized treatments. After one growing season seedlings were harvested, ectomycorrhizas identified using DNA sequencing, and seedlings analyzed for leaf nutrient concentration and content, and biomass parameters. EcMF community structure-nutrient interactions were tested using nonmetric multidimensional scaling (NMDS) combined with vector analysis of foliar nutrients and biomass. We identified three dominant species: Amphinema sp., Atheliaceae sp., and Thelephora terrestris. NMDS?+?envfit revealed significant community effects on seedling nutrition that differed with fertilization treatment. PERMANOVA and regression analyses uncovered significant species effects on host nutrient concentration, content, and stoichiometry. Amphinema sp. had a significant positive effect on phosphorus (P), calcium and zinc concentration, and P content; in contrast, T. terrestris had a negative effect on P concentration. In the unfertilized treatment, percent abundance of the Amphinema sp. negatively affected foliar nitrogen (N) concentration but not content, and reduced foliar N/P. In fertilized seedlings, Amphinema sp. was positively related to foliar concentrations of N, magnesium, and boron, and both concentration and content of manganese, and Atheliaceae sp. had a negative relationship with P content. Findings shed light on the community and species effects on seedling condition, revealing clear functional differences among dominants. The approach used should be scalable to explore function in more complex communities composed of unculturable EcMF. PMID:25904341

  12. Growth, water relations and photosynthesis of seedlings and resprouts after fire

    NASA Astrophysics Data System (ADS)

    Clemente, Adelaide S.; Rego, Francisco C.; Correia, Otlia A.

    2005-05-01

    Seasonal patterns of growth, water relations, photosynthesis and leaf characteristics were compared between obligate seeders ( Cistus monspeliensis and Cistus ladanifer) and resprouters ( Arbutus unedo and Pistacia lentiscus) from the first to the second year after fire. We hypothesized that seedlings would be more water-limited than resprouts due to their shallower root systems. Regarding water use strategies, Cistus species are drought semi-deciduous and A. unedo and P. lentiscus are evergreen sclerophylls, therefore, comparisons were based on the relative deviation from mature conspecific plants. Seedlings and resprouts had higher shoot elongation and leaf production than mature plants, and over an extended period. Differences from mature plants were larger in resprouts, with two-fold transpiration, leaf conductance and photosynthesis in late spring/early summer. Seedlings of C. monspeliensis exhibited higher transpiration and leaf conductance than mature plants, while those of C. ladanifer only exhibited higher water potential. Growth increments and ameliorated water relations and photosynthesis after fire were attributed to an increase in water and nutrient availability. The small differences in water relations and photosynthesis between seedlings and mature conspecifics are in accordance with the prediction of seedlings experiencing higher water limitation than resprouts. We attribute these results to differences in root systems: resprouters benefited from an increase in root/shoot ratios and the presence of deep roots whereas Cistus seedlings relied on very shallow roots, which cannot provide assess to deep water during summer. Nevertheless, seedlings did not show evidence of experiencing a more severe water limitation than mature conspecifics, which we attributed to the presence of efficient mechanisms of avoiding and tolerating water stress. The results are discussed in relation to post-fire demography of seeders and resprouters in Mediterranean communities.

  13. Hydrogen sulphide improves adaptation of Zea mays seedlings to iron deficiency.

    PubMed

    Chen, Juan; Wu, Fei-Hua; Shang, Yu-Ting; Wang, Wen-Hua; Hu, Wen-Jun; Simon, Martin; Liu, Xiang; Shangguan, Zhou-Ping; Zheng, Hai-Lei

    2015-11-01

    Hydrogen sulphide (H2S) is emerging as a potential molecule involved in physiological regulation in plants. However, whether H2S regulates iron-shortage responses in plants is largely unknown. Here, the role of H2S in modulating iron availability in maize (Zea mays L. cv Canner) seedlings grown in iron-deficient culture solution is reported. The main results are as follows: Firstly, NaHS, a donor of H2S, completely prevented leaf interveinal chlorosis in maize seedlings grown in iron-deficient culture solution. Secondly, electron micrographs of mesophyll cells from iron-deficient maize seedlings revealed plastids with few photosynthetic lamellae and rudimentary grana. On the contrary, mesophyll chloroplasts appeared completely developed in H2S-treated maize seedlings. Thirdly, H2S treatment increased iron accumulation in maize seedlings by changing the expression levels of iron homeostasis- and sulphur metabolism-related genes. Fourthly, phytosiderophore (PS) accumulation and secretion were enhanced by H2S treatment in seedlings grown in iron-deficient solution. Indeed, the gene expression of ferric-phytosiderophore transporter (ZmYS1) was specifically induced by iron deficiency in maize leaves and roots, whereas their abundance was decreased by NaHS treatment. Lastly, H2S significantly enhanced photosynthesis through promoting the protein expression of ribulose-1,5-bisphosphate carboxylase large subunit (RuBISCO LSU) and phosphoenolpyruvate carboxylase (PEPC) and the expression of genes encoding RuBISCO large subunit (RBCL), small subunit (RBCS), D1 protein (psbA), and PEPC in maize seedlings grown in iron-deficient solution. These results indicate that H2S is closely related to iron uptake, transport, and accumulation, and consequently increases chlorophyll biosynthesis, chloroplast development, and photosynthesis in plants. PMID:26208645

  14. Herbivory of tropical rain forest tree seedlings correlates with future mortality.

    PubMed

    Eichhorn, Markus P; Nilus, Reuben; Compton, Stephen G; Hartley, Sue E; Burslem, David F R P

    2010-04-01

    Tree seedlings in tropical rain forests are subject to both damage from natural enemies and intense interspecific competition. This leads to a trade-off in investment between defense and growth, and it is likely that tree species specialized to particular habitats tailor this balance to correspond with local resource availability. It has also been suggested that differential herbivore impacts among tree species may drive habitat segregation, favoring species adapted to particular resource conditions. In order to test these predictions, a reciprocal transplant experiment in Sabah, Malaysia, was established with seedlings of five species of Dipterocarpaceae. These were specialized to either alluvial (Hopea nervosa, Parashorea tomentella) or sandstone soils (Shorea multiflora, H. beccariana), or were locally absent (S. fallax). A total of 3000 seedlings were planted in paired gap and understory plots in five sites on alluvial and sandstone soils. Half of all seedlings were fertilized. Seedling growth and mortality were recorded in regular samples over 3.5 years, and rates of insect herbivore damage were estimated from censuses of foliar tissue loss on marked mature leaves and available young leaves. Greater herbivory rates on mature leaves had no measurable effects on seedling growth but were associated with a significantly increased likelihood of mortality during the following year. In contrast, new-leaf herbivory rates correlated with neither growth nor mortality. There were no indications of differential impacts of herbivory among the five species, nor between experimental treatments. Herbivory was not shown to influence segregation of species between soil types, although it may contribute toward differential survival among light habitats. Natural rates of damage were substantially lower than have been shown to influence tree seedling growth and mortality in previous manipulative studies. PMID:20462123

  15. Early selection of black spruce seedlings and global change: Which genotypes should we favor

    SciTech Connect

    Wang, Z.M.; Lechowicz, M.J.; Potvin, C. )

    1994-08-01

    The effects of both soil fertility and predicted changes in climate on growth of different families of black spruce, Picea mariana (Mill.) B.S.P., during the first growing season was studied. The results were used to examine whether reforestation programs should consider changing their preferred family lines in anticipation of altered performance given global climate change. We grew seedlings of 16 open-pollinated maternal families of black spruce under phytotron conditions simulating present and mid-21st century climatic conditions during the growing season. The realistic, simulated future climate included both elevated CO[sub 2] levels and seasonally appropriate increases in mean daily temperature. To explore the dependence of climatic responses on site quality, seedlings were irrigated with solutions having either 5 or 100 mg/L of nitrogen. The lower nitrogen level represents a poor site for black spruce growth and survival, but the higher level provides ample nitrogen. We also recorded seed size for each seedling to evaluate the degree to which maternal investments might buffer responses to future climate and fertility during the first year on the seedbed. Seedling survival and growth increase both under the future climate regime and with nitrogen fertilization. The two factors interacted synergistically, with nitrogen enrichment significantly enhancing the positive effects of the future climate regime. Nitrogen-poor conditions, however, did not preclude a positive seedling response to the future climate. Our results indicate that seedling survival and height growth are highly dependent upon initial seed mass, seed germination, and seedling, survival and growth, but their relative performances did not vary significantly among the treatments. These results suggest that black spruce families selected for rapid growth under present conditions will also do well in the future, at least in terms of early establishment and performance on sites regenerated by seeding.

  16. Ethylene-orchestrated circuitry coordinates a seedling's response to soil cover and etiolated growth.

    PubMed

    Zhong, Shangwei; Shi, Hui; Xue, Chang; Wei, Ning; Guo, Hongwei; Deng, Xing Wang

    2014-03-18

    The early life of terrestrial seed plants often starts under the soil in subterranean darkness. Over time and through adaptation, plants have evolved an elaborate etiolation process that enables seedlings to emerge from soil and acquire autotrophic ability. This process, however, requires seedlings to be able to sense the soil condition and relay this information accordingly to modulate both the seedlings' growth and the formation of photosynthetic apparatus. The mechanism by which soil overlay drives morphogenetic changes in plants, however, remains poorly understood, particularly with regard to the means by which the cellular processes of different organs are coordinated in response to disparate soil conditions. Here, we illustrate that the soil overlay quantitatively activates seedlings' ethylene production, and an EIN3/EIN3-like 1-dependent ethylene-response cascade is required for seedlings to successfully emerge from the soil. Under soil, an ERF1 pathway is activated in the hypocotyl to slow down cell elongation, whereas a PIF3 pathway is activated in the cotyledon to control the preassembly of photosynthetic machinery. Moreover, this latter PIF3 pathway appears to be coupled to the ERF1-regulated upward-growth rate. The coupling of these two pathways facilitates the synchronized progression of etioplast maturation and hypocotyl growth, which, in turn, ultimately enables seedlings to maintain the amount of protochlorophyllide required for rapid acquisition of photoautotrophic capacity without suffering from photooxidative damage during the dark-to-light transition. Our findings illustrate the existence of a genetic signaling pathway driving soil-induced plant morphogenesis and define the specific role of ethylene in orchestrating organ-specific soil responses in Arabidopsis seedlings. PMID:24599595

  17. Physiology, morphology, and ozone uptake of leaves of black cherry seedlings, saplings, and canopy trees.

    PubMed

    Fredericksen, T S; Joyce, B J; Skelly, J M; Steiner, K C; Kolb, T E; Kouterick, K B; Savage, J E; Snyder, K R

    1995-01-01

    Patterns of ozone uptake were related to physiological, morphological, and phenological characteristics of different-sized black cherry trees (Prunus serotina Ehrh.) at a site in central Pennsylvania. Calculated ozone uptake differed among open-grown seedlings, forest gap saplings, and canopy trees and between leaves in the upper and lower crown of saplings and canopy trees. On an instantaneous basis, seedling leaves had the greatest ozone uptake rates of all tree size classes due to greater stomatal conductance and higher concentrations of ozone in their local environment. A pattern of higher stomatal conductance of seedlings was consistent with higher incident photosynthetically-active radiation, stomatal density, and predawn xylem water potentials for seedlings relative to larger trees. However, seedlings displayed an indeterminate pattern of shoot growth, with the majority of their leaves produced after shoot growth had ceased for canopy and sapling trees. Full leaf expansion occurred by mid-June for sapling and canopy trees. Because many of their leaves were exposed to ozone for only part of the growing season, seedlings had a lower relative exposure over the course of the growing season, and subsequently lower cumulative uptake, of ozone than canopy trees and a level of uptake similar to upper canopy leaves of saplings. Visible injury symptoms were not always correlated with patterns in ozone uptake. Visible symptoms were more apparent on seedling leaves in concurrence with their high instantaneous uptake rates. However, visible injury was more prevalent on leaves in the lower versus upper crown of canopy trees and saplings, even though lower crown leaves had less ozone uptake. Lower crown leaves may be more sensitive to ozone per unit uptake than upper crown leaves because of their morphology. In addition, the lower net carbon uptake of lower crown leaves may limit repair and anti-oxidant defense processes. PMID:15091517

  18. Seedling responses to water pulses in shrubs with contrasting histories of grassland encroachment.

    PubMed

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

    2014-01-01

    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 3.00.3 d) and grew faster (by 8.70.5 mg d?). Shoot mass at harvest was higher in A. greggii (996 mg seedling?) than in P. velutina (742 mg seedling?), but there was no significant difference in root mass (543 and 492 mg seedling?, respectively). Taproot elongation was differentially sensitive to water supply: under the highest initial watering pulse, taproots were 5219 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. PMID:24475263

  19. Hydrogen sulphide improves adaptation of Zea mays seedlings to iron deficiency

    PubMed Central

    Chen, Juan; Wu, Fei-Hua; Shang, Yu-Ting; Wang, Wen-Hua; Hu, Wen-Jun; Simon, Martin; Liu, Xiang; Shangguan, Zhou-Ping; Zheng, Hai-Lei

    2015-01-01

    Hydrogen sulphide (H2S) is emerging as a potential molecule involved in physiological regulation in plants. However, whether H2S regulates iron-shortage responses in plants is largely unknown. Here, the role of H2S in modulating iron availability in maize (Zea mays L. cv Canner) seedlings grown in iron-deficient culture solution is reported. The main results are as follows: Firstly, NaHS, a donor of H2S, completely prevented leaf interveinal chlorosis in maize seedlings grown in iron-deficient culture solution. Secondly, electron micrographs of mesophyll cells from iron-deficient maize seedlings revealed plastids with few photosynthetic lamellae and rudimentary grana. On the contrary, mesophyll chloroplasts appeared completely developed in H2S-treated maize seedlings. Thirdly, H2S treatment increased iron accumulation in maize seedlings by changing the expression levels of iron homeostasis- and sulphur metabolism-related genes. Fourthly, phytosiderophore (PS) accumulation and secretion were enhanced by H2S treatment in seedlings grown in iron-deficient solution. Indeed, the gene expression of ferric-phytosiderophore transporter (ZmYS1) was specifically induced by iron deficiency in maize leaves and roots, whereas their abundance was decreased by NaHS treatment. Lastly, H2S significantly enhanced photosynthesis through promoting the protein expression of ribulose-1,5-bisphosphate carboxylase large subunit (RuBISCO LSU) and phosphoenolpyruvate carboxylase (PEPC) and the expression of genes encoding RuBISCO large subunit (RBCL), small subunit (RBCS), D1 protein (psbA), and PEPC in maize seedlings grown in iron-deficient solution. These results indicate that H2S is closely related to iron uptake, transport, and accumulation, and consequently increases chlorophyll biosynthesis, chloroplast development, and photosynthesis in plants. PMID:26208645

  20. Seedling establishment in a masting desert shrub parallels the pattern for forest trees

    NASA Astrophysics Data System (ADS)

    Meyer, Susan E.; Pendleton, Burton K.

    2015-05-01

    The masting phenomenon along with its accompanying suite of seedling adaptive traits has been well studied in forest trees but has rarely been examined in desert shrubs. Blackbrush (Coleogyne ramosissima) is a regionally dominant North American desert shrub whose seeds are produced in mast events and scatter-hoarded by rodents. We followed the fate of seedlings in intact stands vs. small-scale disturbances at four contrasting sites for nine growing seasons following emergence after a mast year. The primary cause of first-year mortality was post-emergence cache excavation and seedling predation, with contrasting impacts at sites with different heteromyid rodent seed predators. Long-term establishment patterns were strongly affected by rodent activity in the weeks following emergence. Survivorship curves generally showed decreased mortality risk with age but differed among sites even after the first year. There were no detectable effects of inter-annual precipitation variability or site climatic differences on survival. Intraspecific competition from conspecific adults had strong impacts on survival and growth, both of which were higher on small-scale disturbances, but similar in openings and under shrub crowns in intact stands. This suggests that adult plants preempted soil resources in the interspaces. Aside from effects on seedling predation, there was little evidence for facilitation or interference beneath adult plant crowns. Plants in intact stands were still small and clearly juvenile after nine years, showing that blackbrush forms cohorts of suppressed plants similar to the seedling banks of closed forests. Seedling banks function in the absence of a persistent seed bank in replacement after adult plant death (gap formation), which is temporally uncoupled from masting and associated recruitment events. This study demonstrates that the seedling establishment syndrome associated with masting has evolved in desert shrublands as well as in forests.

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

    NASA Technical Reports Server (NTRS)

    Ng, Y. K.; Moore, R.

    1985-01-01

    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.

  2. Ectomycorrhizal fungi mediate indirect effects of a bark beetle outbreak on secondary chemistry and establishment of pine seedlings.

    PubMed

    Karst, Justine; Erbilgin, Nadir; Pec, Gregory J; Cigan, Paul W; Najar, Ahmed; Simard, Suzanne W; Cahill, James F

    2015-11-01

    Dendroctonus ponderosae has killed millions of Pinus contorta in western North America with subsequent effects on stand conditions, including changes in light intensity, needle deposition, and the composition of fungal community mutualists, namely ectomycorrhizal fungi. It is unknown whether these changes in stand conditions will have cascading consequences for the next generation of pine seedlings. To test for transgenerational cascades on pine seedlings, we tested the effects of fungal inoculum origin (beetle-killed or undisturbed stands), light intensity and litter (origin and presence) on seedling secondary chemistry and growth in a glasshouse. We also tracked survival of seedlings over two growing seasons in the same stands from which fungi and litter were collected. Fungal communities differed by inoculum origin. Seedlings grown with fungi collected from beetle-killed stands had lower monoterpene concentrations and fewer monoterpene compounds present compared with seedlings grown with fungi collected from undisturbed stands. Litter affected neither monoterpenes nor seedling growth. Seedling survival in the field was lower in beetle-killed than in undisturbed stands. We demonstrate that stand mortality caused by prior beetle attacks of mature pines have cascading effects on seedling secondary chemistry, growth and survival, probably mediated through effects on below-ground mutualisms. PMID:26033270

  3. Infrared light-emitting diode radiation causes gravitropic and morphological effects in dark-grown oat seedlings

    NASA Technical Reports Server (NTRS)

    Johnson, C. F.; Brown, C. S.; Wheeler, R. M.; Sager, J. C.; Chapman, D. K.; Deitzer, G. F.

    1996-01-01

    Oat (Avena sativa cv Seger) seedlings were irradiated with IR light-emitting diode (LED) radiation passed through a visible-light-blocking filter. Infrared LED irradiated seedlings exhibited differences in growth and gravitropic response when compared to seedlings grown in darkness at the same temperature. Thus, the oat seedlings in this study were able to detect IR LED radiation. These findings call into question the use of IR LED as a safe-light for some photosensitive plant response experiments. These findings also expand the defined range of wavelengths involved in radiation-gravity (light-gravity) interactions to include wavelengths in the IR region of the spectrum.

  4. Drivers of seedling survival in a temperate forest and their relative importance at three stages of succession.

    PubMed

    Yan, Yan; Zhang, Chunyu; Wang, Yuxi; Zhao, Xiuhai; von Gadow, Klaus

    2015-10-01

    Negative density dependence (NDD) and niche partitioning have been perceived as important mechanisms for the maintenance of species diversity. However, little is known about their relative contributions to seedling survival. We examined the effects of biotic and abiotic neighborhoods and the variations of biotic neighborhoods among species using survival data for 7503 seedlings belonging to 22 woody species over a period of 2years in three different forest types, a half-mature forest (HF), a mature forest (MF), and an old-growth forest (OGF), each of these representing a specific successional stage in a temperate forest ecosystem in northeastern China. We found a convincing evidence for the existence of NDD in temperate forest ecosystems. The biotic and abiotic variables affecting seedlings survival change with successional stage, seedling size, and age. The strength of NDD for the smaller (<20cm in height) and younger seedlings (1-2years) as well as all seedlings combined varies significantly among species. We found no evidence that a community compensatory trend (CCT) existed in our study area. The results of this study demonstrate that the relative importance of NDD and habitat niche partitioning in driving seedling survival varies with seedling size and age and that the biotic and abiotic factors affecting seedlings survival change with successional stage. PMID:26664679

  5. Salt stress-induced seedling growth inhibition coincides with differential distribution of serotonin and melatonin in sunflower seedling roots and cotyledons.

    PubMed

    Mukherjee, Soumya; David, Anisha; Yadav, Sunita; Baluka, Frantiek; Bhatla, Satish Chander

    2014-12-01

    Indoleamines regulate a variety of physiological functions during the growth, morphogenesis and stress-induced responses in plants. Present investigations report the effect of NaCl stress on endogenous serotonin and melatonin accumulation and their differential spatial distribution in sunflower (Helianthus annuus) seedling roots and cotyledons using HPLC and immunohistochemical techniques, respectively. Exogenous serotonin and melatonin treatments lead to variable effect on hypocotyl elongation and root growth under NaCl stress. NaCl stress for 48?h increases endogenous serotonin and melatonin content in roots and cotyledons, thus indicating their involvement in salt-induced long distance signaling from roots to cotyledons. Salt stress-induced accumulation of serotonin and melatonin exhibits differential distribution in the vascular bundles and cortex in the differentiating zones of the primary roots, suggesting their compartmentalization in the growing region of roots. Serotonin and melatonin accumulation in oil body rich cells of salt-treated seedling cotyledons correlates with longer retention of oil bodies in the cotyledons. Present investigations indicate the possible role of serotonin and melatonin in regulating root growth during salt stress in sunflower. Effect of exogenous serotonin and melatonin treatments (15 ?M) on sunflower seedlings grown in the absence or presence of 120 mM NaCl substantiates their role on seedling growth. Auxin and serotonin biosynthesis are coupled to the common precursor tryptophan. Salt stress-induced root growth inhibition, thus pertains to partial impairment of auxin functions caused by increased serotonin biosynthesis. In seedling cotyledons, NaCl stress modulates the activity of N-acetylserotonin O-methyltransferase (HIOMT; EC 2.1.1.4), the enzyme responsible for melatonin biosynthesis from N-acetylserotonin. PMID:24799301

  6. Uptake of natural and synthetic estrogens by maize seedlings.

    PubMed

    Card, Marcella L; Schnoor, Jerald L; Chin, Yu-Ping

    2012-08-29

    Runoff from manure-fertilized crop fields constitutes a significant source of natural estrogens (e.g., estradiol [17β-E2] and estrone [E1]) and synthetic estrogen mimics (e.g., zeranol [α-ZAL] and zearalanone [ZAN]) in the environment. However, processes such as sorption to and uptake by plants may inhibit the environmental mobility of hormonally active compounds. Sorption to dried root tissue was assessed in batch sorption tests, and resulting sorption isotherms were nonlinear at aqueous concentrations below 0.1 μM and linear above that limit. To evaluate the role of crop plants in the environmental fate of such compounds, we exposed hydroponic solutions containing 2 μM 17β-E2, E1, α-ZAL, or ZAN to maize seedlings. After 22 days of exposure, α-ZAL and ZAN concentrations decreased by more than 96%, and 17β-E2 and E1 were undetectable. The decrease in α-ZAL and ZAN concentrations in maize-exposed solutions was initially slow, but the observed uptake exceeded that predicted by sorption alone within 3 d. All four estrogens were detected in root tissues at concentrations up to 0.19 μmol g(-1), with concentrations peaking after 1-3 days of exposure. Only 17β-E2 and α-ZAL were detected in shoots, and maximum concentrations were measured after 2 days for 17β-E2 (0.02 μmol g(-1)) and 16 days for α-ZAL (0.8 nmol g(-1)). Concentrations measured in root and shoot tissues were 82% or less than those predicted by a partition-limited uptake model, which is attributed to transformation and possibly irreversible binding processes. PMID:22816790

  7. Proteome analysis of roots of wheat seedlings under aluminum stress.

    PubMed

    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

    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 μM 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

  8. Effects of O/sub 2/ concentration on rice seedlings

    SciTech Connect

    Alpi, A.; Beevers, H.

    1983-01-01

    The ability of rice, wheat, and oat seedlings to germinate and grow as the O/sub 2/ concentration was lowered to zero was compared. The germination of rice was completely unaffected by O/sub 2/ supply, whereas that of oats and wheat was strongly retarded at levels below 5% O/sub 2/. In contrast to the coleoptiles of oats and wheat and to roots of all three species where growth was progressively diminished as the O/sub 2/ concentration was lowered, that of the rice coleoptile was progressively increased. However, the dry weight and content of protein, sugars, and cellulose were all depressed in the rice coleoptile in anoxia, and the levels of several respiratory enzymes, particularly those of mitochondria, were also much lower than those of the coleoptiles grown in air. In 1% O/sub 2/, the growth of the rice coleoptile was similar to that in air. The effect of ethanol concentration on germination and growth of rice was measured. Coleoptile growth was reduced when the ethanol concentration exceeded 40 millimolarity, and root growth was somewhat more sensitive. Coleoptiles of all three species grown in air were transferred to N/sub 2/ and ethanol accumulation was measured over 24 hours. The rate of ethanol accumulation in oats was close to that in rice, and in all three species the amounts of ethanol lost to the surrounding medium were those expected from simple diffusion from the tissue. The ability of the rice coleoptile to grow in anoxia is apparently not due to a particularly low rate of ethanol formation or to unusual ethanol tolerance. Any explanation of the success of rice in anoxia must encompass the much lower rate of ATP synthesis than that in air and account for the biochemical deficiencies of the coleoptile.

  9. Seed deposition patterns and the survival of seeds and seedlings of the palm Euterpe edulis

    NASA Astrophysics Data System (ADS)

    Pizo, Marco A.; Simão, Isaac

    2001-08-01

    The seed deposition pattern created by a seed disperser is one of the components of the efficiency of a species as seed disperser, and ultimately may influence the recruitment of a plant species. In this study, we used the seeds of a bird-dispersed forest palm, Euterpe edulis, to investigate the effects of two distinct seed deposition patterns created by birds that defecate (clumped pattern) and regurgitate seeds (loose-clumped pattern) on the survival of seeds experimentally set in an E. edulis-rich site, and of seedlings grown under shade-house conditions. The study was conducted in the lowland forest of Parque Estadual Intervales, SE Brazil. Clumped and loose-clumped seeds were equally preyed upon by rodents and insects. Although clumped and isolated seedlings had the same root weight after 1 year, the isolated seedlings survived better and presented more developed shoots, suggesting intraspecific competition among clumped seedlings. Our results indicate that animals that deposit E. edulis seeds in faecal clumps (e.g. cracids, tapirs) are less efficient seed dispersers than those that regurgitate seeds individually (e.g. trogons, toucans). Intraspecific competition among seedlings growing from faecal clumps is a likely process preventing the occurrence of clumps of adult palms.

  10. Exploring the natural variation for seedling traits and their link with seed dimensions in tomato.

    PubMed

    Khan, Noorullah; Kazmi, Rashid H; Willems, Leo A J; van Heusden, Adriaan W; Ligterink, Wilco; Hilhorst, Henk W M

    2012-01-01

    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. PMID:22952841

  11. The gravitropic setpoint angle of dark-grown rye seedlings and the role of ethylene.

    PubMed

    Edelmann, Hans G; Gudi, Gennadi; Khnemann, Frank

    2002-07-01

    The orientation growth of coleoptiles of dark-grown seedlings of rye (Secale cereale L. cv. Marder II), when grown under various conditions, was analysed with respect to the gravivector ('gravitropic setpoint angle', GSA). Coleoptiles growing through moist vermiculite attain and maintain a GSA with an average of about 180 degrees, i.e. a vertical orientation. Seedlings growing uncovered either on the surface of vermiculite or positionally fixed on filter paper attain and maintain a GSA of 140-150 degrees (i.e. deviating from the vertical by an average of 30-40 degrees ). Changing the position of the embryo relative to the horizontally fixed seed kernel or of the angle of the seed with respect to gravity during germination (+/-40 degrees relative to the horizontal) had no significant effect on the subsequent GSA of both covered and uncovered seedlings. The GSA of uncovered coleoptiles could be restored close to 180 degrees by treatment of the seedlings with ethylene, either applied via ethephon or 1-aminocyclopropane-1-carboxylic acid (ACC) as well as by fruit-released ethylene. The results are discussed with respect to the mechanism of the regulation of gravitropic growth of grass seedlings. PMID:12096101

  12. Effects of photochemical smog and mineral nutrition on ponderosa pine seedlings.

    PubMed

    Bytnerowicz, A; Poth, M; Takemoto, B K

    1990-01-01

    Two-year-old seedlings of ponderosa pine (Pinus ponderosa Dougl. ex Laws) were exposed to ambient concentrations of photochemical smog (AA) and clean air (CA) during a single field season at Tanbark Flat of the San Gabriel Mountains in the Los Angeles Basin. The seedlings were grown in a perlite-vermiculite medium with full supply of nutrients (based on modified Hoagland solution); reduced to 50% supply of N; reduced to 50% supply of Mg; and reduced to 50% supply of N+Mg. No significant effects of air pollution exposures on injury development, stem growth and concentrations of plant pigments were determined. The seedlings in the AA treatment had decreased N concentration in current year needles compared with CA seedlings; however, the needle concentrations of other elements did not change. Reduction of N supply in the growing medium caused decreased N, P, Ca, K and chlorophyll a concentrations in needles. Stem growth of the seedlings with reduced N supply was significantly decreased as well. No changes in stem growth or chemical composition of plants with reduced Mg supply were noted. Reduction of supply of nutrients did not change responses of trees to the air pollution exposures. PMID:15092211

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

    PubMed Central

    Inglis, Peter W.; Ciampi, Ana Y.; Salomo, Antonieta N.; Costa, Tnia da S.A.; Azevedo, Vnia C.R.

    2014-01-01

    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

  14. Light intensity alters the extent of arsenic toxicity in Helianthus annuus L. seedlings.

    PubMed

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

    2014-06-01

    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., 6mgkg(-1) soil, As1; and high, i.e., 12mgkg(-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

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

    PubMed

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

    2011-06-01

    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

  16. The detection of chlorophyll content for salt stress of the wheat seedling by hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Wu, Qiong; Zhu, Dazhou; Wang, Cheng; Ma, Zhihong; Zhang, Dongyan; Chen, Kun; Wang, Jihua

    2011-08-01

    An auto-development pushbroom imaging spectrometer (PIS) with wavelength range of 400-1000 nm was applied to measure the chlorophyll content of wheat seedling. It showed that according to images of spectral imaging for leaves of Chinese Spring (Salt-sensitive), Zhouyuan 9369(common and high-yield) and Changwu 134(salt-tolerant) wheat seedling under salt stress, growth of salt-sensitive Chinese Spring wheat seedling was inhibited and it was feasible to carry out qualitative analysis. Images could intuitively reflect morphological information of growth status of wheat seedling and could show spectral differences of different leaves and different locations of one leave. Also, it was feasible to identify green and yellow locations of leaf and to carry out qualitative analysis. The tested sites of spectrum and the chlorophyll content measured sites were on the same area of single leaf. After measuring the hyperspectral image of leaf, the mean reflectance spectra of each leaf was calculated Totally, 126 samples were collected, which were then divided into a calibration set and a prediction set. Partial least square regression (PLSR) method was used to build the calibration model. Results showed that the extracted hyperspectral spectra had high correlation with chlorophyll content. The correlation coefficient of the calibration model is R=0.8138, the standard error of prediction is SEP=4.75. The results indicated that hyperspectral imaging were suitable for the non-invasive detection of chlorophyll content of wheat seedling.

  17. Warming and neighbor removal affect white spruce seedling growth differently above and below treeline.

    PubMed

    Okano, Kyoko; Bret-Harte, M Syndonia

    2015-01-01

    Climate change is expected to be pronounced towards higher latitudes and altitudes. Warming triggers treeline and vegetation shifts, which may aggravate interspecific competition and affect biodiversity. This research tested the effects of a warming climate, habitat type, and neighboring plant competition on the establishment and growth of white spruce (Picea glauca (Moench) Voss) seedlings in a subarctic mountain region. P. glauca seedlings were planted in June 2010 under 4 different treatments (high/control temperatures, with/without competition) in 3 habitats (alpine ridge above treeline/tundra near treeline /forest below treeline habitats). After two growing seasons in 2011, growth, photosynthesis and foliar C and N data were obtained from a total of 156, one-and-a-half year old seedlings that had survived. Elevated temperatures increased growth and photosynthetic rates above and near treeline, but decreased them below treeline. Competition was increased by elevated temperatures in all habitat types. Our results suggest that increasing temperatures will have positive effects on the growth of P. glauca seedlings at the locations where P. glauca is expected to expand its habitat, but increasing temperatures may have negative effects on seedlings growing in mature forests. Due to interspecific competition, possibly belowground competition, the upslope expansion of treelines may not be as fast in the future as it was the last fifty years. PMID:25729635

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

    PubMed

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

    2006-01-01

    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

  19. Involvement of phytochrome A in suppression of photomorphogenesis in rice seedling grown in red light.

    PubMed

    Roy, Ansuman; Sahoo, Dinabandhu; Tripathy, Baishnab C

    2013-12-01

    Plants have evolved a remarkable capacity to track and respond to fluctuations of light quality and intensity that influence photomorphogenesis facilitated through several photoreceptors, which include a small family of phytochromes. Rice seedlings grown on germination paper in red light for 48 h having their shoot bottom exposed had suppressed photomorphogenesis and were deficient in chlorophyll. Seedlings grown under identical light regime having their shoot bottom covered were green and accumulated chlorophyll. Further, etiolated seedlings with their shoot bottom exposed, when grown in 4 min red/far-red cycles for 48 h, accumulated chlorophyll demonstrating the reversal of suppression of photomorphogenesis by far-red light. It implicates the involvement of phytochrome. Immunoblot analysis showed the persistence of photolabile phytochrome A protein for 48 h in seedlings grown in red light with their shoot bottom exposed, suggesting its involvement in suppression of photomorphogenesis. This was further corroborated in phyA seedlings that turned green when grown in red light having their shoot bottom exposed. Calmodulin (CaM) antagonist N-(6-aminohexyl)-5-chloro-1-napthalene sulphonamide or trifluoperazine substantially restored photomorphogenesis both in the wild type (WT) and phyA demonstrating the involvement of CaM-dependent kinases in the down-regulation of the greening process. Results demonstrate that red light-induced suppression of photomorphogenesis, perceived in the shoot bottom, is a red high irradiance response of PhyA. PMID:23495675

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

    PubMed

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

    2014-01-01

    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

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

    PubMed

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

    2006-06-01

    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 dormancy. Subjecting the seeds to wet heat at 80 and 100 degrees C and light treatment terminated dormancy both in the fresh and stored seeds. Light greatly enhanced the germination percentage of seeds by about 70%. There was gradual increase in germination percentage with increase in storage period in dormancy-released seeds. The mean LAR (Leaf Area Ratio), NAR (Net Assimilation Rate) and RGR (Relative Growth Rate) are comparatively high in young seedlings. Concentrations of 0.5-2.0% of Gramoxone, Primextra and Galex are toxic to 1 month old seedlings. For eradication, the seedlings should be attacked at one month stage. PMID:18494310

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

    NASA Astrophysics Data System (ADS)

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

    2007-09-01

    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 r c=0.89, SEC=6.41 mg/g, r v=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.

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

    PubMed

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

    2012-02-01

    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

  4. An endogenous growth pattern of roots is revealed in seedlings grown in microgravity.

    PubMed

    Millar, Katherine D L; Johnson, Christina M; Edelmann, Richard E; Kiss, John Z

    2011-10-01

    In plants, sensitive and selective mechanisms have evolved to perceive and respond to light and gravity. We investigated the effects of microgravity on the growth and development of Arabidopsis thaliana (ecotype Landsberg) in a spaceflight experiment. These studies were performed with the Biological Research in Canisters (BRIC) hardware system in the middeck region of the space shuttle during mission STS-131 in April 2010. Seedlings were grown on nutrient agar in Petri dishes in BRIC hardware under dark conditions and then fixed in flight with paraformaldehyde, glutaraldehyde, or RNAlater. Although the long-term objective was to study the role of the actin cytoskeleton in gravity perception, in this article we focus on the analysis of morphology of seedlings that developed in microgravity. While previous spaceflight studies noted deleterious morphological effects due to the accumulation of ethylene gas, no such effects were observed in seedlings grown with the BRIC system. Seed germination was 89% in the spaceflight experiment and 91% in the ground control, and seedlings grew equally well in both conditions. However, roots of space-grown seedlings exhibited a significant difference (compared to the ground controls) in overall growth patterns in that they skewed to one direction. In addition, a greater number of adventitious roots formed from the axis of the hypocotyls in the flight-grown plants. Our hypothesis is that an endogenous response in plants causes the roots to skew and that this default growth response is largely masked by the normal 1?g conditions on Earth. PMID:21970704

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

    PubMed

    Inglis, Peter W; Ciampi, Ana Y; Salomo, Antonieta N; Costa, Tnia da S A; Azevedo, Vnia C R

    2014-03-01

    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

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

    PubMed

    Yez-Espinosa, Laura; Flores, Joel; Rodrguez Milln, Paulina S; Rubio Mndez, Gabriel

    2014-05-01

    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 0.0MPa (day 1), -0.1MPa (day 40), -1.0MPa (day 90), -1.5MPa (day 130), and a control (0.0MPa 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 -1.0MPa, 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 -1.0MPa. 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

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

    PubMed

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

    2013-04-01

    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

  8. Size effects of chitooligomers on the growth and photosynthetic characteristics of wheat seedlings.

    PubMed

    Zhang, Xiaoqian; Li, Kecheng; Liu, Song; Xing, Ronge; Yu, Huahua; Chen, Xiaolin; Li, Pengcheng

    2016-03-15

    In this study, nine chitooligomers (COSs) including seven single COSs (chitobiose to chitooctaose) and two COS fractions with narrow degrees of polymerization (DPs) (DP8-10, DP10-12) were prepared and applied to wheat seedlings to investigate the size effects of COSs on the growth and photosynthesis parameters of wheat seedlings. The results showed that the activities of COS were closely related to their DPs, and DP>3 was necessary to insure a significant promotion effect on the growth and photosynthesis. Moreover, chitoheptaose exhibited the optimal activity compared with other COS samples. After 7 days of chitoheptaose treatment, the growth parameters of wheat seedlings could be significantly improved and the contents of soluble sugar, soluble protein and chlorophyll were increased by 59.4%, 22.0% and 20.3%, respectively. In addition, chitoheptaose could significantly enhance the net photosynthetic rate of wheat seedlings with the values of Fv/Fo, qP and Rfd increased by 11.0%, 18.6% and 14.7%, respectively, while NPQ was decreased obviously, which might resulted in the promotion of light utilization efficiency and the growth of wheat seedlings. PMID:26794734

  9. Protection of the Photosynthetic Apparatus from Extreme Dehydration and Oxidative Stress in Seedlings of Transgenic Tobacco

    PubMed Central

    Personat, José-María; Tejedor-Cano, Javier; Lindahl, Marika; Diaz-Espejo, Antonio; Jordano, Juan

    2012-01-01

    A genetic program that in sunflower seeds is activated by Heat Shock transcription Factor A9 (HaHSFA9) has been analyzed in transgenic tobacco seedlings. The ectopic overexpression of the HSFA9 program protected photosynthetic membranes, which resisted extreme dehydration and oxidative stress conditions. In contrast, heat acclimation of seedlings induced thermotolerance but not resistance to the harsh stress conditions employed. The HSFA9 program was found to include the expression of plastidial small Heat Shock Proteins that accumulate only at lower abundance in heat-stressed vegetative organs. Photosystem II (PSII) maximum quantum yield was higher for transgenic seedlings than for non-transgenic seedlings, after either stress treatment. Furthermore, protection of both PSII and Photosystem I (PSI) membrane protein complexes was observed in the transgenic seedlings, leading to their survival after the stress treatments. It was also shown that the plastidial D1 protein, a labile component of the PSII reaction center, and the PSI core protein PsaB were shielded from oxidative damage and degradation. We infer that natural expression of the HSFA9 program during embryogenesis may protect seed pro-plastids from developmental desiccation. PMID:23227265

  10. Impact of chronic cadmium exposure on growth of pin oak seedlings. [Quercus palustris

    SciTech Connect

    Kazimir, J.; Brennan, E.

    1986-12-01

    Two-year-old pin oak (Quercus palustris Muenchh.) seedlings were grown in sand culture and given complete nutrient solution with or without 0.1 ..mu..g/ml Cd (as CdCl/sub 2/) for one or two growing seasons from May to September and the effect on growth determined. Cadmium accumulated primarily in the roots of the seedlings during chronic exposure but was translocated slowly into the shoot over time. Growth of newly planted two-year-old seedlings was stimulated after one year of Cd treatment, but that of established three-year-old seedlings was not affected. The more frequent application of Cd and the larger root system of the older seedlings resulted in a greater Cd accumulation in the root than that associated with growth stimulation. No measurable effect of Cd on tree growth was detected after two successive years of cadmium treatment; however, the percentage of trees exhibiting foliar toxicity symptoms increased. Where Cd treatment was terminated after one year and the trees replanted in uncontaminated sand, leaves continued to show high levels of Cd due to translocation from perennial tissue, but this response was not reflected in any growth change.

  11. Local Adaptation Enhances Seedling Recruitment Along an Altitudinal Gradient in a High Mountain Mediterranean Plant

    PubMed Central

    Gimnez-Benavides, Luis; Escudero, Adrin; Iriondo, Jos M.

    2007-01-01

    Background and Aims Germination and seedling establishment, which are critical stages in the regeneration process of plant populations, may be subjected to natural selection and adaptive evolution. The aims of this work were to assess the main limitations on offspring performance of Silene ciliata, a high mountain Mediterranean plant, and to test whether local adaptation at small spatial scales has a significant effect on the success of establishment. Methods Reciprocal sowing experiments were carried out among three populations of the species to test for evidence of local adaptation on seedling emergence, survival and size. Studied populations were located at the southernmost margin of the species' range, along the local elevation gradient that leads to a drought stress gradient. Key Results Drought stress in summer was the main cause of seedling mortality even though germination mainly occurred immediately after snowmelt to make the best use of soil moisture. The results support the hypothesis that species perform better at the centre of their altitudinal range than at the boundaries. Evidence was also found of local adaptation in seedling survival and growth along the whole gradient. Conclusions The local adaptation acting on seedling emergence and survival favours the persistence of remnant populations on the altitudinal and latitudinal margins of mountain species. In a global warming context, such processes may help to counteract the contraction of this species' ranges and the consequent loss of habitat area. PMID:17307775

  12. Non-destructive high-throughput DNA extraction and genotyping methods for cotton seeds and seedlings.

    PubMed

    Zheng, Xiuting; Hoegenauer, Kevin A; Maeda, Andrea B V; Wang, Fei; Stelly, David M; Nichols, Robert L; Jones, Don C

    2015-05-01

    Extensive use of targeted PCR-based genotyping is precluded for many plant research laboratories by the cost and time required for DNA extraction. Using cotton (Gossypium hirsutum) as a model for plants with medium-sized seeds, we report here manual procedures for inexpensive non-destructive high-throughput extraction of DNA suitable for PCR-based genotyping of large numbers of individual seeds and seedlings. By sampling only small amounts of cotyledon tissue of ungerminated seed or young seedlings, damage is minimized, and viability is not discernibly affected. The yield of DNA from each seed or seedling is typically sufficient for 1000 or 500 PCR reactions, respectively. For seeds, the tissue sampling procedure relies on a modified 96-well plate that is used subsequently for seed storage. For seeds and seedlings, the DNA is extracted in a strongly basic DNA buffer that is later neutralized and diluted. Extracts can be used directly for high-throughput PCR-based genotyping. Any laboratory can thus extract DNA from thousands of individual seeds/seedlings per person-day at a very modest cost for consumables (~$0.05 per sample). Being non-destructive, our approach enables a wide variety of time- and resource-saving applications, such as marker-assisted selection (MAS), before planting, transplanting, and flowering. PMID:25967902

  13. Femtosecond laser-fabricated biochip for studying symbiosis between Phormidium and seedling root

    NASA Astrophysics Data System (ADS)

    Ishikawa, Nobuaki; Hanada, Yasutaka; Ishikawa, Ikuko; Sugioka, Koji; Midorikawa, Katsumi

    2015-06-01

    We present the fabrication of a waveguide-like structure in a polydimethylsiloxane (PDMS) polymer substrate using a femtosecond laser to study the mechanism of symbiosis between filamentous cyanobacteria, Phormidium, and a seedling root. While symbiosis occurring underground promotes the growth of vegetable seedlings, the details of the mechanism remain unclear. Understanding the mechanisms of Phormidium gliding to the seedling root will facilitate improving the mat formation of Phormidium, which will lead to increased vegetable production. We assumed a symbiosis mechanism in which sunlight propagates through the seedling root and is scattered underground to guide the Phormidium gliding. Once attached to the root, Phormidium uses the scattered light for photosynthesis. Photosynthetic products, in turn, promote an increase in Phormidium mat formation and vegetable growth. To verify this assumption, the optical characteristics of the seedling root were investigated. A waveguide-like structure with the same optical characteristics of the root was subsequently fabricated by femtosecond laser in PDMS polymer to assess the light illumination effect on Phormidium behavior.

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

    NASA Technical Reports Server (NTRS)

    Desrosiers, M. F.; Bandurski, R. S.

    1988-01-01

    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.

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

    PubMed Central

    Méndez-Hurtado, Alejandra; Rangel-Méndez, René; Flores, Joel

    2013-01-01

    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. PMID:24453802

  16. The effect of ectomycorrhizal fungi forming symbiosis with Pinus pinaster seedlings exposed to cadmium.

    PubMed

    Sousa, Nadine R; Ramos, Miguel A; Marques, Ana P G C; Castro, Paula M L

    2012-01-01

    Cadmium is one of the most toxic heavy metals and its accumulation in the upper layers of forest soils affects plants, microorganisms and their interactions. Adequate strategies for the reforestation of metal contaminated sites are of vital importance. The aim of this work was to evaluate the response of Pinus pinaster seedlings to Cd exposure and to assess the effect of inoculation with two selected ectomycorrhizal fungi, Suillus bovinus and Rhizopogon roseolus on that response. Seedlings were exposed to soil contaminated at 15 and 30 mg Cd kg(-1). Shoot biomass of P. pinaster decreased ca. 36% when exposed to 15 mg Cd kg(-1). Overall, colonization by S. bovinus significantly enhanced shoot development up to 30% in contaminated soil while colonization by R. roseolus produced no significant effect at both Cd concentrations tested and significantly increased the level of Cd in the shoots at both Cd concentrations. Metal accumulation in the shoots and roots of non-inoculated and S. bovinus-inoculated seedlings increased at the higher Cd levels whereas R. roseolus-inoculated seedlings were not sensitive to Cd variation in the soil. The results from our research show that inoculation with ECM fungi has a significant impact on metal uptake and development of P. pinaster seedlings; the differential response induced by the two tested species highlights the importance of selecting the appropriate strains for nursery inoculation, and, as such, this biological tool ought to be considered in reforestation processes of heavy metal contaminated areas by woody species. PMID:22115613

  17. Combined effects of lead and acid rain on photosynthesis in soybean seedlings.

    PubMed

    Hu, Huiqing; Wang, Lihong; Liao, Chenyu; Fan, Caixia; Zhou, Qing; Huang, Xiaohua

    2014-10-01

    To explore how lead (Pb) and acid rain simultaneously affect plants, the combined effects of Pb and acid rain on the chlorophyll content, chlorophyll fluorescence reaction, Hill reaction rate, and Mg(2+)-ATPase activity in soybean seedlings were investigated. The results indicated that, when soybean seedlings were treated with Pb or acid rain alone, the chlorophyll content, Hill reaction rate, Mg(2+)-ATPase activity, and maximal photochemical efficiency (F(v)/F(m)) were decreased, while the initial fluorescence (F 0) and maximum quantum yield (Y) were increased, compared with those of the control. The combined treatment with Pb and acid rain decreased the chlorophyll content, Hill reaction rate, Mg(2+)-ATPase activity, F(v)/F(m), and Y and increased F 0 in soybean seedlings. Under the combined treatment with Pb and acid rain, the two factors showed additive effects on the chlorophyll content in soybean seedlings and exhibited antagonistic effects on the Hill reaction rate. Under the combined treatment with high-concentration Pb and acid rain, the two factors exhibited synergistic effects on the Mg(2+)-ATPase activity, F 0, F v/F m, as well as Y. In summary, the inhibition of the photosynthetic process is an important physiological basis for the simultaneous actions of Pb and acid rain in soybean seedlings. PMID:25069575

  18. [Effects of exogenous melatonin on ascorbate metabolism system in cucumber seedlings under high temperature stress].

    PubMed

    Xu, Xiang-dong; Sun, Yan; Guo, Xiao-qin; Sun, Bo; Zhang, Jian

    2010-10-01

    Taking cucumber cultivar 'Jinchun 4' as test material, and by the method of foliar spraying, this paper studied the effects of exogenous melatonin (MT) on the ascorbic acid (AsA) metabolism system in cucumber seedlings under high temperature stress. Under the stress of high temperature, the leaf hydrogen peroxide (H2O2) and malondialdehyde (MDA) contents of the cucumber seedlings increased obviously, ascorbic acid (AsA) and glutathione (GSH) contents had a persistent decrease while dehydroascorbate (DHA) and oxidized-glutathione (GSSG) contents had a gradual increase, and AsA/DHA and GSH/GSSG decreased greatly. The activities of ascorbate peroxidase (APx), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and glutathione reductase (GR) in the seedling leaves under high temperature stress increased markedly, with the maximum after 12 h stress. Foliar spraying MT could effectively restrain the accumulation of H2O2 and MDA in seedling leaves, increase the leaf AsA and GSH contents and the activities of ascorbic acid metabolizing enzymes APx, MDHAR, GR and DHAR, and accordingly, enhance the H2O2-scavenging ability, inhibit the production of active O2, maintain the stability of cell membrane, reduce the damage of high temperature to the plants, and improve the ability of cucumber seedlings against high temperature stress. PMID:21328946

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

    PubMed

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

    2012-08-01

    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

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

    PubMed

    Andrs-Alpuente, Antonio; Snchez, Sergio; Martn, Mara; Aguirre, Angel Javier; Barriuso, Juan J

    2014-04-01

    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

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

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

    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.

  2. Dynamics and partitioning of the ionome in seeds and germinating seedlings of winter oilseed rape.

    PubMed

    Eggert, Kai; von Wirn, Nicolaus

    2013-09-01

    Germination and seedling establishment are among the most critical phases in the development of plants, and seed vigour has become an important trait for the selection of robust crop cultivars. Little is known about the potentially limiting role of mineral nutrients in early metabolic and developmental processes during germination. Therefore, we assessed the ionome and relative distribution of mineral elements in different seed and seedling tissues of oilseed rape (Brassica napus L.) and monitored the internal allocation of nutrients during germination. In seeds, cotyledons harboured the main pool of K, P, S, Mg, Fe, Mn and Zn, whereas the seed coat contained most of the Ca, Na, B, Cu and Mo. Although the early root and hypocotyl tissue expanded first, concentrations of most elements were initially low. Re-allocation of elements to the root/hypocotyl tissue from other pools set in two days after seed imbibition and was most rapid for K. Relative to the critical deficiency levels of vegetative tissues, seed tissues were particularly low in B, K and Fe. Further analyses of the ionome of seeds and seedlings, grouped according to their germination efficiency, indicated that in particular low S, Mg and Ca coincided with germination failure. This study documents highly dynamic changes in the ionome of seed and seedling tissues and provides evidence for potentially limiting elements during early germination and seedling establishment in rapeseed. PMID:23939714

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

    PubMed

    Stöckel, Marcus; Těšitelová, Tamara; Jersáková, Jana; Bidartondo, Martin I; Gebauer, Gerhard

    2014-04-01

    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

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

    PubMed Central

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

    2012-01-01

    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. PMID:22952841

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

    PubMed

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

    2009-11-01

    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

  6. Diffusion of polybrominated diphenyl ether (PBDE) from an e-waste recycling area to the surrounding regions in Southeast China.

    PubMed

    Zhao, Ya-Xian; Qin, Xiao-Fei; Li, Yan; Liu, Peng-Yan; Tian, Mi; Yan, Shi-Shuai; Qin, Zhan-Fen; Xu, Xiao-Bai; Yang, Yong-Jian

    2009-09-01

    Using Cinnamomum camphora (C. camphora) leaves as biomonitors, we investigated that the diffusion of polybrominated diphenyl ethers (PBDEs) from an e-waste recycling area to the surrounding regions. Variance in sigma(32)PBDEs concentrations (0.46-399.93 ng g(-1) dry weight) in the leaves showed that PBDEs from the e-waste recycling area diffused into the surrounding regions, and resulted in a halo of PBDEs contamination, at least 74 km in radius. The attenuation of sigma(32)PBDEs in the diffusing process fitted in log-linear regression. The difference in the attenuating slopes of linear equations among different directions can be explained by terrain and wind direction. The attenuation of PBDE congeners also fitted well in log-linear regression. The findings that similar attenuating slopes and characteristic travel distance among congeners suggest that the transport behavior of lower brominated congeners might not differ from that of higher brominated congeners in short-range scale. PMID:19665753

  7. Interactive effects of cadmium and acid rain on photosynthetic light reaction in soybean seedlings.

    PubMed

    Sun, Zhaoguo; Wang, Lihong; Chen, Minmin; Wang, Lei; Liang, Chanjuan; Zhou, Qing; Huang, Xiaohua

    2012-05-01

    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

  8. Ion beam transformation with corn DNA alters proteinase expression in rice seedling roots.

    PubMed

    Li, W C; Ji, S D; Wang, X C; Li, Z K; Zhang, H C; Tian, C Z; Liu, Y L; Duan, C X

    2015-01-01

    Corn DNA was introduced into dry seeds of rice (cv. 'YuJing-6') by ion beam irradiation. Proteinase activities in rice seedling roots were subsequently analyzed by renaturation electrophoresis at pH 4.5, 7.0, and 8.5. Proteinase activity was more pronounced on gels at higher pH. Irradiation of rice seedling roots caused the loss of some proteinase bands at all pH conditions although a novel 50-kDa band was found at both pH 7.0 and 8.5. No new proteinase activity was detected at pH 4.5. However, novel bands and bands showing stronger activity were observed at pH 7.0 and 8.5. The data indicate that the expression of proteinases in rice seedling roots was altered following low energy ion beam mediated transformation with corn DNA. PMID:26125936

  9. Testing the allometric scaling relationships with seedlings of two tree species

    NASA Astrophysics Data System (ADS)

    Chen, Xiongwen; Li, Bai-Lian

    2003-07-01

    Theoretical and empirical investigations of allometric scaling relationships have recently been receiving great attention in biology and ecology. Some recent studies suggest that a scale invariant property is universally valid for all plants, regardless of their phyletic affiliation or habitat. In this study, we test allometric relationships, including photosynthetic rate, biomass, stem diameter and height, using a field experiment with 2-year-old seedlings of Fraxinus mandshurica and Phellodendron amurense that are under three kinds of soil water treatments. There are no fixed scaling exponents for the two species at three soil water treatments. The scaling exponents of various allometric relationships are different between the two species, and even distinct among the individuals of same species at different soil water treatments. The scaling exponent of seedlings seems complicated, and the possible allometric relationships of seedlings may depend on species and partially be controlled by environmental factors.

  10. The Effect of Increased Sediment Accretion on the Survival and Growth of Rhizophora apiculataSeedlings

    NASA Astrophysics Data System (ADS)

    Terrados, J.; Thampanya, U.; Srichai, N.; Kheowvongsri, P.; Geertz-Hansen, O.; Boromthanarath, S.; Panapitukkul, N.; Duarte, C. M.

    1997-11-01

    The effects of experimental sediment accretion on the survival and growth ofRhizophora apiculataseedlings planted on an expanding mud flat in Pak Phanang Bay (south-east Thailand) were assessed. Seedling mortality rates increased linearly (R2=087,F=759,P<00001) with increasing sediment accretion, at a rate of 3% per cm of sediment deposited, and implied a 96% increase in mortality at the highest sediment accretion applied (32 cm). Similarly, seedling growth declined linearly with increasing sediment accretion (r=-095,P<001) with the seedlings receiving 32 cm of sediment showing no significant growth. These results clearly show thatRhizophora apiculataseedlings will not be efficient colonizers of coastal areas exposed to sudden events of high (>4 cm) sediment accretion and, therefore, afforestation programmes based on this species are unlikely to be successful in such areas.

  11. Photosynthetic Independence of Light-induced Anthocyanin Formation in Zea Seedlings 1

    PubMed Central

    Duke, Stephen O.; Fox, Sue B.; Naylor, Aubrey W.

    1976-01-01

    Results are reported which support the view that the photosynthetic photosystems are not involved in the high irradiance response (HIR) phenomenon of light-dependent anthocyanin biosynthesis in dark-grown Zea mays L. seedlings. A negative correlation between change in greening rates and change in light-dependent anthocyanin accumulation rates with age was demonstrated. Lack of chlorophyll synthesis in a strain of maize possessing a temperature-sensitive lesion for chlorophyll synthesis could not be correlated with light-induced anthocyanin accumulation. Furthermore, seedlings totally lacking photosynthetic capabilities, either due to a genetic lesion or to excision of all photosynthetic tissue, had an enhanced rate of photoinduced anthocyanin formation. This evidence indicates that the HIR results in the initiation of processes that are in competition with chloroplast development for substrate in normal, intact seedlings. PMID:16659449

  12. Influence of extremely low-frequency electric fields on the growth of Vigna radiata seedlings.

    PubMed

    Costanzo, Evelina

    2011-10-01

    The biological effects of extremely low-frequency electric fields (ELF) on living organisms have been explored in many studies, but the results are controversial and only a few studies investigated the influence of the intensity of the applied field on seedling growth. Here we assess the effects of a 50 Hz sinusoidal electric field on the early growth of Vigna radiata seedlings while varying the field intensity. Experiments performed in a dark, constant-climate chamber on several thousands of seedlings show that the field produces an inhibitory effect at a low field intensity and an enhancing one at a higher intensity. The maximum negative effect occurs at about 450 V/m, which is an intensity much lower than the exposure limits currently in force in the safety regulations. PMID:21416477

  13. Climate Change Alters Seedling Emergence and Establishment in an Old-Field Ecosystem

    SciTech Connect

    Classen, Aimee T; Norby, Richard J; Campany, Courtney E; Sides, Katherine E; Weltzin, Jake

    2010-01-01

    In shaping how ecosystems respond to climatic change, ecosystem structure can dominate over physiological responses of individuals, especially under conditions of multiple, simultaneous changes in environmental factors. Ecological succession drives large-scale changes in ecosystem structure over time, but the mechanisms whereby climatic change alters succession remain unresolved. Here, we investigate effects of atmospheric and climatic change on seedling establishment, recognizing that small shifts in seedling establishment of different species may have long-term repercussions on the transition of fields to forests in the future. Our 4-year experiment in an old-field ecosystem revealed that response of seedling emergence to different combinations of atmospheric CO2 concentration, air temperature, and soil moisture depends on seed phenology, the timing of seed arrival into an ecosystem. We conclude that seed phenology is an important plant trait that can shape, and help predict, the trajectories of ecosystems under climatic change.

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

    PubMed

    Krber, Niklas; Wittkop, Benjamin; Bus, Anja; Friedt, Wolfgang; Snowdon, Rod J; Stich, Benjamin

    2012-10-01

    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

  15. A comparative field study of growth and survival of Sierran conifer seedlings

    SciTech Connect

    Kern, R.A.

    1996-12-31

    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).

  16. Effects of hydrogen fluoride on water relations and photosynthesis in White Pine (Pinus strobus) seedlings

    SciTech Connect

    Rakowski, K.J.; Zwiazek, J.J. )

    1991-05-01

    Transpiration, photosynthesis, water potential components and tissue fluoride concentrations were determined in mildly drought stressed 9-week-old seedlings fumigated with HF. Only those seedlings which showed no visible signs of fluoride injury were selected for the measurements. Photosynthesis decreased after 1 and 7 days of fumigation with 2, 4 and 20 ppb HF. A decrease in the transpiration rates has been observed after 2, 7 and 22 days of 0.5 ppb HF treatment and after 2 days of 2 ppb HF treatment. The same treatments which reduced transpiration rates resulted in an increase in osmotic potentials and water potentials. Possible mechanism of HF-induced alterations in seedling water relations by altering stomatal movements is discussed.

  17. Phytotoxicity assessment of phenanthrene, pyrene and their mixtures by a soil-based seedling emergence test.

    PubMed

    Song, Yu-Fang; Gong, Ping; Zhou, Qi-Xing; Sun, Tie-Heng

    2005-01-01

    Seedling emergence tests were conducted in a meadow brown soil using five plant species (i.e., Chinese cabbage, green onion, tomato, turnip and wheat) to determine the phytotoxicity of phenanthrene, pyrene and their mixtures. The soil was amended with up to 1000 mg/kg soil of phenanthrene or 600 mg/kg soil of pyrene. Seedling emergence and root growth were measured. The results indicated that root elongation was more sensitive than seedling emergence. Root length decreased with increasing phenanthrene or pyrene concentrations( p < or = 0.05). Phenanthrene was more phytotoxic than pyrene. The lowest observable adverse effect concentration (LOAEC) was 10 mg/kg for phenanthrene when tested with green onion, and 50 mg/kg for pyrene when tested with wheat. Among the five species, wheat was found to be the most sensitive. When amended jointly at or below their respective LOAEC, phenanthrene and pyrene produced a synergistic toxic effect. PMID:16158583

  18. Phytotoxicity of zinc and manganese to seedlings grown in soil contaminated by zinc smelting

    USGS Publications Warehouse

    Beyer, W.N.; Green, C.E.; Beyer, M.; Chaney, R.L.

    2013-01-01

    Historic emissions from two zinc smelters have injured the forest on Blue Mountain near Palmerton, Pennsylvania, USA. Seedlings of soybeans and five tree species were grown in a greenhouse in a series of mixtures of smelter-contaminated and reference soils and then phytotoxic thresholds were calculated. As little as 10% Palmerton soil mixed with reference soil killed or greatly stunted seedlings of most species. Zinc was the principal cause of the phytotoxicity to the tree seedlings, although Mn and Cd may also have been phytotoxic in the most contaminated soil mixtures. Calcium deficiency seemed to play a role in the observed phytotoxicity. Exposed soybeans showed symptoms of Mn toxicity. A test of the effect of liming on remediation of the Zn and Mn phytotoxicity caused a striking decrease in Sr-nitrate extractable metals in soils and demonstrated that liming was critical to remediation and restoration.

  19. Diversity of ectomycorrhizal fungi naturally established on containerised Pinus seedlings in nursery conditions.

    PubMed

    El Karkouri, Khalid; Martin, Francis; Douzery, J P Emmanuel; Mousain, Daniel

    2005-01-01

    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

  20. Soil type affects Pinus ponderosa var. scopulorum (Pinaceae) seedling growth in simulated drought experiments1

    PubMed Central

    Lindsey, Alexander J.; Kilgore, Jason S.

    2013-01-01

    • Premise of the study: Effects of drought stress and media type interactions on growth of Pinus ponderosa var. scopulorum germinants were investigated. • Methods and Results: Soil properties and growth responses under drought were compared across four growth media types: two native soils (dolomitic limestone and granite), a soil-less industry standard conifer medium, and a custom-mixed conifer medium. After 35 d of growth, the seedlings under drought stress (reduced watering) produced less shoot and root biomass than watered control seedlings. Organic media led to decreased root biomass, but increased root length and shoot biomass relative to the mineral soils. • Conclusions: Media type affected root-to-shoot biomass partitioning of P. ponderosa var. scopulorum, which may influence net photosynthetic rates, growth, and long-term seedling survival. Further work should examine how specific soil properties like bulk density and organic matter influence biomass allocation in greenhouse studies. PMID:25202578

  1. An improved high-throughput screening assay for tunicamycin sensitivity in Arabidopsis seedlings

    PubMed Central

    McCormack, Maggie E.; Liu, Xiaoyu; Jordan, Melissa R.; Pajerowska-Mukhtar, Karolina M.

    2015-01-01

    Tunicamycin (Tm) sensitivity assays are a useful method for studies of endoplasmic reticulum stress and the unfolded protein response in eukaryotic cells. While Tm sensitivity and Tm recovery assays have been previously described, these existing methods are time-consuming, labor intensive, and subjected to mechanical wounding. This study shows an improved method of testing Tm sensitivity in Arabidopsis using liquid Murashige and Skoog medium versus the traditional solid agar plates. Liquid medium bypasses the physical manipulation of seedlings, thereby eliminating the risk of potential mechanical damage and additional unwanted stress to seedlings. Seedlings were subjected to comparative treatments with various concentrations of Tm on both solid and liquid media and allowed to recover. Determination of fresh weight, chlorophyll contents analysis and qRT-PCR results confirm the efficacy of using liquid medium to perform quantitative Tm stress assays. PMID:26441998

  2. Mechanism of artemisinin phytotoxicity action: induction of reactive oxygen species and cell death in lettuce seedlings.

    PubMed

    Yan, Zhi-Qiang; Wang, Dan-Dan; Ding, Lan; Cui, Hai-Yan; Jin, Hui; Yang, Xiao-Yan; Yang, Jian-She; Qin, Bo

    2015-03-01

    Artemisinin has been recognized as an allelochemical that inhibits growth of several plant species. However, its mode of action is not well clarified. In this study, the mechanism of artemisinin phytotoxicity on lettuce seedlings was investigated. Root and shoot elongation of lettuce seedlings were inhibited by artemisinin in a concentration-dependent manner. The compound effectively arrested cell division and caused loss of cell viability in root tips of lettuce. Overproduction of reactive oxygen species (ROS) was induced by artemisinin. Lipid peroxidation, proline overproduction and reduction of chlorophyll content in lettuce seedlings were found after treatments. These results suggested that artemisinin could induce ROS overproduction, which caused membrane lipids peroxidation and cell death, and impacted mitosis and physiological processes, resulting in growth inhibition of receptor plants. PMID:25658194

  3. Influence of Light and Ambient Carbon Dioxide Concentration on Nitrate Assimilation by Intact Barley Seedlings 1

    PubMed Central

    Aslam, Muhammad; Huffaker, Ray C.; Rains, D. William; Rao, K. Prasad

    1979-01-01

    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. PMID:16660883

  4. Phytotoxicity of zinc and manganese to seedlings grown in soil contaminated by zinc smelting.

    PubMed

    Beyer, W N; Green, C E; Beyer, M; Chaney, R L

    2013-08-01

    Historic emissions from two zinc smelters have injured the forest on Blue Mountain near Palmerton, Pennsylvania, USA. Seedlings of soybeans and five tree species were grown in a greenhouse in a series of mixtures of smelter-contaminated and reference soils and then phytotoxic thresholds were calculated. As little as 10% Palmerton soil mixed with reference soil killed or greatly stunted seedlings of most species. Zinc was the principal cause of the phytotoxicity to the tree seedlings, although Mn and Cd may also have been phytotoxic in the most contaminated soil mixtures. Calcium deficiency seemed to play a role in the observed phytotoxicity. Exposed soybeans showed symptoms of Mn toxicity. A test of the effect of liming on remediation of the Zn and Mn phytotoxicity caused a striking decrease in Sr-nitrate extractable metals in soils and demonstrated that liming was critical to remediation and restoration. PMID:23685629

  5. The role of onion-associated fungi in bulb mite infestation and damage to onion seedlings.

    PubMed

    Ofek, Tal; Gal, Shira; Inbar, Moshe; Lebiush-Mordechai, Sara; Tsror, Leah; Palevsky, Eric

    2014-04-01

    In Israel Rhizoglyphus robini is considered to be a pest in its own right, even though the mite is usually found in association with fungal pathogens. Plant protection recommendations are therefore to treat germinating onions seedlings, clearly a crucial phase in crop production, when mites are discovered. The aim of this study was to determine the role of fungi in bulb mite infestation and damage to germinating onion seedlings. Accordingly we (1) evaluated the effect of the mite on onion seedling germination and survival without fungi, (2) compared the attraction of the mite to species and isolates of various fungi, (3) assessed the effect of a relatively non-pathogenic isolate of Fusarium oxysporum on mite fecundity, and (4) determined the effects of the mite and of F. oxysporum separately and together, on onion seedling germination and sprout development. A significant reduction of seedling survival was recorded only in the 1,000 mites/pot treatment, after 4 weeks. Mites were attracted to 6 out of 7 collected fungi isolates. Mite fecundity on onion sprouts infested with F. oxysporum was higher than on non-infested sprouts. Survival of seedlings was affected by mites, fungi, and their combination. Sprouts on Petri dishes after 5 days were significantly longer in the control and mite treatments than both fungi treatments. During the 5-day experiment more mites were always found on the fungi-infected sprouts than on the non-infected sprouts. Future research using suppressive soils to suppress soil pathogens and subsequent mite damage is proposed. PMID:24242868

  6. Influence of biodynamic preparations on compost development and resultant compost extracts on wheat seedling growth.

    PubMed

    Reeve, Jennifer R; Carpenter-Boggs, Lynne; Reganold, John P; York, Alan L; Brinton, William F

    2010-07-01

    Biodynamic (BD) agriculture, a form of organic agriculture, includes the use of specially fermented preparations, but peer-reviewed studies on their efficacy are rare. Composting of a grape pomace and manure mixture was studied in two years (2002 and 2005) with and without the BD compost preparations. Water extracts of finished composts were then used to fertigate wheat seedlings, with and without added inorganic fertilizer. BD-treated mixtures had significantly greater dehydrogenase activity than did untreated (control) mixtures during composting, suggesting greater microbial activity in BD-treated compost. In both years there was a distinct compost effect on wheat shoot and root biomass irrespective of supplemental fertilizer. Shoot biomass was highest in all treatments receiving 1% compost extract. Wheat seedlings that received 1% compost extract in 2005 grew similar root and shoot biomass as fertilized seedlings, despite only containing 30% as much nitrogen as the fertilizer treatment. In both years seedlings that received fertilizer plus 1% compost extract produced 22-61% more shoot biomass and 40-66% more root biomass than seedlings that received fertilizer alone, even at higher rates. In 2002 a 1% extract of BD compost grew 7% taller wheat seedlings than did 1% extract of untreated compost. At 0.1% only BD extract grew taller plants than water, but in 2002 only. No effect on shoot or root biomass was seen at 0.1%. Our results support the use of compost extracts as fertilizer substitutes or supplements, testimonial reports on the growth promoting effects of compost extracts, and the occasional superiority of BD compost to untreated compost. PMID:20202833

  7. Biological Control of Damping-Off of Alfalfa Seedlings with Bacillus cereus UW85

    PubMed Central

    Handelsman, Jo; Raffel, Sandra; Mester, Ellen H.; Wunderlich, Lynn; Grau, Craig R.

    1990-01-01

    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 PMID:16348145

  8. Label-free quantitative proteomics analysis of etiolated maize seedling leaves during greening.

    PubMed

    Shen, Zhuo; Li, Ping; Ni, Rui-Juan; Ritchie, Mark; Yang, Chuan-Ping; Liu, Gui-Feng; Ma, Wei; Liu, Guan-Jun; Ma, Ling; Li, Shu-Juan; Wei, Zhi-Gang; Wang, Hong-Xia; Wang, Bai-Chen

    2009-11-01

    To better understand light regulation of C(4) plant maize development, we investigated dynamic proteomic differences between green seedlings (control), etiolated seedlings, and etiolated seedlings illuminated for 6 or 12 h using a label-free quantitative proteomics approach based on nanoscale ultraperformance liquid chromatography-ESI-MS(E). Among more than 400 proteins identified, 73 were significantly altered during etiolated maize seedling greening. Of these 73 proteins, 25 were identified as membrane proteins that seldom had been identified with two-dimensional electrophoresis methods, indicating the power of our label-free method for membrane protein identification; 31 were related to light reactions of chlorophyll biosynthesis, photosynthesis, and photosynthetic carbon assimilation. The expression of photosystem II subunits was highly sensitive to light; most of them were not identified in etiolated maize seedlings but drastically increased upon light exposure, indicating that the complex process of biogenesis of the photosynthetic apparatus correlates with the transition from a dark-grown to a light-grown morphology. However, transcriptional analysis indicated that most transcripts encoding these proteins were not regulated by light. In contrast, the levels of mRNAs and proteins for enzymes involved in carbon assimilation were tightly regulated by light. Additionally phosphoenolpyruvate carboxykinase, the key enzyme of the phosphoenolpyruvate carboxykinase C(4) pathway, was more tightly regulated by light than the key enzymes of the NADP-malic enzyme C(4) pathway. Furthermore phosphoenolpyruvate carboxylase 1C, which was originally reported to be specifically expressed in roots, was also identified in this study; expression of this enzyme was more sensitive to light than its isoforms. Taken together, these results represent a comprehensive dynamic protein profile and light-regulated network of C(4) plants for etiolated seedling greening and provide a basis for further study of the mechanism of gene function and regulation in light-induced development of C(4) plants. PMID:19666873

  9. Acclimation to frost alters proteolytic response of wheat seedlings to drought.

    PubMed

    Grudkowska, Ma?gorzata; Zagda?ska, Barbara

    2010-11-01

    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 no effect on the proteolytic activity of the tolerant cultivar and depressed the azocaseinolytic activity of the sensitive cultivar (Tortija). However, the observed depression of enzyme activity was fully reversible under dehydration. The content of soluble proteins was reduced in dehydrated non-acclimated and in acclimated seedlings of the frost-sensitive cultivar, but increased in acclimated seedlings of the tolerant cultivar. The cysteine proteinases were preferentially induced under water deficiency when assessment was based on the inhibitory effect of iodoacetate on azocasein hydrolysis. Separation of cysteine proteinases by SDS-PAGE containing gelatin as a substrate showed two bands with apparent molecular masses of 36 and 38 kDa in the sensitive cultivar, and a third band was detected (42 kDa) in the resistant cultivar. Water deficit and low temperature induced the new cysteine proteinases of molecular masses about 29, 33 and 42 kDa in sensitive non-acclimated seedlings. Polyclonal antibodies raised against Arabidopsis proteinase responsive to drought (RD21) cross-reacted with the protein in the 33 kDa region, and a slight signal was obtained in the 42 kDa region, but only in dehydrated seedlings acclimated to frost. Several polypeptides of molecular masses of 30, 22, 20 and 18 kDa were recognized by the Arabidopsis aleurain-like proteinase (AtALEU) antibodies. The results presented indicate that cysteine proteinases are potentially responsible for both low temperature and drought tolerance. PMID:20674076

  10. Growth response and drought susceptibility of red spruce seedlings exposed to simulated acidic rain and ozone

    SciTech Connect

    Lee, W.S.; Chevone, B.I.; Seiler, J.R. )

    1990-06-01

    One-year-old seedlings of red spruce were exposed to O{sub 3} ({le} 0.025 or 0.10 {mu}l 1{sup {minus}1}, 4 h d{sup {minus}1}, 3 d wk{sup {minus}1}) in combination with simulated rain (pH 5.6 or 3.0, 1 h d{sup {minus}1}, 2 d wk{sup {minus}1}, 0.75 cm h{sup {minus}1}) for 10 weeks. After pollutant treatments, seedlings were subjected to two successive drought cycles. Whole-plant fresh weight increment (FWT) and dry weight were reduced after O{sub 3} exposure, whereas FWT and shoot height growth were increased after simulated rain exposure at pH 3.0 compared to pH 5.6. No interaction between O{sub 3} and rain treatments was observed for any growth variable measured. Foliar concentrations of K and S were greater in seedlings exposed to simulated rain at pH 3.0 compared with those at pH 5.6. Root hydraulic conductivity was highest in seedlings exposed to 0.10 {mu}l l{sup {minus}1} O{sub 3} + pH 3.0 rain solution compared with all other treatments after the first drought cycle. There were no significant O{sub 3} effects on net photosynthesis (Pn), transpiration or water-use efficiency prior to the drought cycles. However, during the second drought cycle, Pn was more sensitive to branch water potential in seedlings exposed to 0.10 {mu}l l{sup {minus}1} O{sub 3} + pH 3.0 solution compared with seedlings exposed to low O{sub 3} + pH 5.6 solution.

  11. [Effects of light intensity on Quercus liaotungensis seed germination and seedling growth].

    PubMed

    Yan, Xing-fu; Wang, Jian-li; Zhou, Li-biao

    2011-07-01

    This paper studied the effects of different shading (55.4%, 18.9%, 5.5%, 2.2%, 0.5% , and 0.3% natural sunlight) on the seed germination and seedling growth of Quercus liaotungensis. The seed germination rate and germination index were the highest (72.5% and 0.22, respectively) at 55.4% natural sunlight, declined with decreasing light intensity, and were the lowest (42.5% and 0.11, respectively) at 0.3% natural sunlight. Strong light had definite delaying effect on the germination. The index of germination vigor increased with decreasing light intensity, being the maximum at 0.5% natural sunlight. The delay of seed germination under strong light could be the selective tradeoff on varied seed fates. Strong light benefited the basal stem diameter and root system growth and dry mass accumulation of Q. liaotunensis seedling, but resulted in the minimum seedlings height (6.06 cm). Greater morphological plasticity was observed for the seedlings under different shading, which lent support to the higher adaptability of the seedlings to light environment. For example, the specific leaf area, specific shoot length, specific root length, and chlorophyll b and total chlorophyll contents were the maximum at 0.5% natural sunlight, being 142.57 cm2 x g(-1), 156.86 cm x g(-1), 271.87 cm x g(-1), 0.07 g x cm(-2), and 0.24 g x cm(-2), respectively, and the minimum at 55.4% natural sunlight, being 44.89 cm2 x g(-1), 52.84 cm x g(-1), 101.98 cm x g(-1), 0.04 g x cm(-2), and 0.15 g x cm(-2), respectively. The variation of the root/shoot ratio of Q. liaotungensis seedlings under different shading could be the effects of the combination of light intensity and water availability. PMID:22007441

  12. Morphometric analyses of petioles of seedlings grown in a spaceflight experiment.

    PubMed

    Johnson, Christina M; Subramanian, Aswati; Edelmann, Richard E; Kiss, John Z

    2015-11-01

    Gravity is a constant unidirectional stimulus on Earth, and gravitropism in plants involves three phases: perception, transduction, and response. In shoots, perception takes place within the endodermis. To investigate the cellular machinery of perception in microgravity, we conducted a spaceflight study with Arabidopsis thaliana seedlings, which were grown in microgravity in darkness using the Biological Research in Canisters (BRIC) hardware during space shuttle mission STS-131. In the 14-day-old etiolated plants, we studied seedling development and the morphological parameters of the endodermal cells in the petiole. Seedlings from the spaceflight experiment (FL) were compared to a ground control (GC), which both were in the BRIC flight hardware. In addition, to assay any potential effects from growth in spaceflight hardware, we performed another control by growing seedlings in Petri dishes in standard laboratory conditions (termed the hardware control, HC). Seed germination was significantly lower in samples grown in flight hardware (FL, GC) compared to the HC. In terms of cellular parameters of endodermal cells, the greatest differences also were between seedlings grown in spaceflight hardware (FL, GC) compared to those grown outside of this hardware (HC). Specifically, the endodermal cells were significantly smaller in seedlings grown in the BRIC system compared to those in the HC. However, a change in the shape of the cell, suggesting alterations in the cell wall, was one parameter that appears to be a true microgravity effect. Taken together, our results suggest that caution must be taken when interpreting results from the increasingly utilized BRIC spaceflight hardware system and that it is important to perform additional ground controls to aid in the analysis of spaceflight experiments. PMID:26376793

  13. The Fungicide Phosphonate Disrupts the Phosphate-Starvation Response in Brassica nigra Seedlings.

    PubMed Central

    Carswell, C.; Grant, B. R.; Theodorou, M. E.; Harris, J.; Niere, J. O.; Plaxton, W. C.

    1996-01-01

    The development of Brassica nigra seedlings over 20 d of growth was disrupted by the fungicide phosphonate (Phi) in a manner inversely correlated with nutritional inorganic phosphate (Pi) levels. The growth of Pi-sufficient (1.25 mM Pi) seedlings was suppressed when 10, but not 5, mM Phi was added to the nutrient medium. In contrast, the fresh weights and root:shoot ratios of Pi-limited (0.15 mM) seedlings were significantly reduced at 1.5 mM Phi, and they progressively declined to about 40% of control values as medium Phi concentration was increased to 10 mM. Intracellular Pi levels generally decreased in Phi-treated seedlings, and Phi accumulated in leaves and roots to levels up to 6- and 16-fold that of Pi in Pi-sufficient and Pi-limited plants, respectively. Extractable activities of the Pi-starvation-inducible enzymes phosphoenolpyruvate phosphatase and inorganic pyrophosphate-dependent phosphofructokinase were unaltered in Pi-sufficient seedlings grown on 5 or 10 mM Phi. However, when Pi-limited seedlings were grown on 1.5 to 10 mM Phi (a) the induction of phosphoenolpyruvate phosphatase and inorganic pyrophosphate-dependent phosphofructokinase activities by Pi limitation was reduced by 40 to 90%, whereas (b) soluble protein concentrations and the activities of the ATP-dependent phosphofructokinase and pyruvate kinase were unaffacted. It is concluded that Phi specifically interrupts processes involved in regulation of the Pi-starvation response in B. nigra. PMID:12226174

  14. Causes and consequences of unequal seedling production in forest trees: a case study in red oaks.

    PubMed

    Moran, Emily V; Clark, James S

    2012-05-01

    Inequality in reproductive success has important implications for ecological and evolutionary dynamics, but lifetime reproductive success is challenging to measure in long-lived species such as forest trees. While seed production is often used as a proxy for overall reproductive success, high mortality of seeds and the potential for trade-offs between seed number and quality draw this assumption into question. Parentage analyses of established seedlings can bring us one step closer to understanding the causes and consequences of variation in reproductive success. In this paper we demonstrate a new method for estimating individual seedling production and average percentage germination, using data from two mixed-species populations of red oaks (Quercus rubra, Q. velutina, Q. falcata, and Q. coccinea). We use these estimates to examine the distribution of female reproductive success and to test the relationship between seedling number and individual seed production, age, and growth rate. We show that both seed and seedling production are highly skewed, roughly conforming to zero-inflated lognormal distributions, rather than to the Poisson or negative-binomial distributions often assumed by population genetics analyses. While the number of established offspring is positively associated with mean annual seed production, a lower proportion of seeds from highly fecund individuals become seedlings. Our red oak populations also show evidence of trade-offs between growth rate and reproductive success. The high degree of inequality in seedling production shown here for red oaks, and by previous studies in other species, suggests that many trees may be more vulnerable to genetic drift than previously thought, if immigration in limited by fragmentation or other environmental changes. PMID:22764494

  15. Carbon translocation patterns associated with new root proliferation during episodic growth of transplanted Quercus rubra seedlings.

    PubMed

    Sloan, Joshua L; Jacobs, Douglass F

    2008-07-01

    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

  16. Organ-coordinated response of early post-germination mahogany seedlings to drought.

    PubMed

    Horta, Lívia P; Braga, Márcia R; Lemos-Filho, José P; Modolo, Luzia V

    2014-04-01

    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

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

    PubMed Central

    Tkalec, Mirta; tefani?, Petra Peharec; Cvjetko, Petra; iki?, Sandra; Pavlica, Mirjana; Balen, Biljana

    2014-01-01

    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 M and 15 M) and Zn (25 M and 50 M) as well as their combinations (10 M or 15 M Cd with either 25 M or 50 M 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. PMID:24475312

  18. Natural populations of Arabidopsis thaliana differ in seedling responses to high-temperature stress

    PubMed Central

    Zhang, Nana; Belsterling, Brian; Raszewski, Jesse; Tonsor, Stephen J.

    2015-01-01

    Little is known about adaptive within-species variation in thermotolerance in wild plants despite its likely role in both functional adaptation at range limits and in predicting response to climate change. Heat shock protein Hsp101, rapidly heat induced in Arabidopsis thaliana, plays a central role in thermotolerance in laboratory studies, yet little is known about variation in its expression in natural populations. We explored variation in thermotolerance and Hsp101 expression in seedlings from 16 natural populations of A. thaliana sampled along an elevation and climate gradient. We tested both naive controls (maintained at 22 C until heat stress) and thermally pre-acclimated plants (exposed to a 38 C 3-h acclimation treatment). After acclimation, seedlings were exposed to one of two heat stresses: 42 or 45 C. Thermotolerance was measured as post-stress seedling survival and root growth. When stressed at 45 C, both thermotolerance and Hsp101 expression were significantly increased by pre-acclimation. However, thermotolerance did not differ between pre-acclimation and control when followed by a 42 C stress. Immediately after heat stress, pre-acclimated seedlings contained significantly more Hsp101 than control seedlings. At 45 C, Hsp101 expression was positively associated with survival (r2 = 0.37) and post-stress root growth (r2 = 0.15). Importantly, seedling survival, post-stress root growth at 45 C and Hsp101 expression at 42 C were significantly correlated with the home sites' first principal component of climate variation. This climate gradient mainly reflects a temperature and precipitation gradient. Thus, the extent of Hsp101 expression modulation and thermotolerance appear to be interrelated and to evolve adaptively in natural populations of A. thaliana. PMID:26286225

  19. Effects of Open-field Warming and Precipitation Manipulation on the Growth of Pinus densiflora Seedlings

    NASA Astrophysics Data System (ADS)

    Park, M. J.; Yoon, S. J.; Han, S. H.; Yun, H. M.; Chang, H.; Son, Y.

    2014-12-01

    The objective of this study was to investigate the effects of open-field artificial warming and precipitation manipulation on Pinus densiflora seedling growth. The temperature in warming plots have been set to be 3C higher than control plots using infrared lamps since April, 2013. Precipitation manipulation consisted of precipitation decrease plots (-30%) with deployment of rain-capturing transparent panels, precipitation increase plots (+30%) with pump installation and drip-irrigation, and control plots. Two-year-old P. densiflora seedlings were planted in April, 2013. Seedling height and root collar diameter were measured in April and November, 2013 and April, 2014, and biomass w