共查询到10条相似文献,搜索用时 251 毫秒
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Aims
The purpose of the present study was to investigate the mechanism of carbon monoxide (CO) and hematin in alleviating the inhibition of Cassia obtusifolia seeds and seedlings. NaCl (100?mM) was used to mimic salinity stress in a series of experiments.Methods
Varying combinations of CO in a saturated aqueous solution and hematin (1.0?μM) were added to seeds and seedlings under salinity stress. Seed germination indices and seedling parameters were investigated.Results
Seed germination and seedling growth were significantly inhibited under salinity stress. NaCl-induced inhibitory effects on seed germination and seedling growth were ameliorated by hematin or the CO aqueous solution. Addition of 1.0?μM hematin or 5?% CO-saturated aqueous solution to seeds and seedlings significantly alleviated damage to the plant cells under salinity stress. Hematin and the CO aqueous solution enhanced chlorophyll concentration, total soluble sugars, free proline, and soluble protein, and improved photosystem II (PSII) photochemical efficiency levels, PSII actual photochemical efficiency, and the photochemical quench coefficient. In contrast, the non-photochemical quenching coefficient decreased. Hematin and the CO aqueous solution also enhanced the activities of superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, and glutathione reductase, thus alleviating oxidative damage, as indicated by decreases in hiobarbituric acid reactive substances, hydrogen peroxide concentration, relative conductivity, and lipoxygenase activity. Heme oxygenase (HO) activity was increased by hematin treatment. Hematin may contribute to endogenous HO-derived CO, since the addition of zinc protoporphyrin IX or hemoglobin reversed the protective effects conferred by hematin specified above.Conclusions
Based on the experimental results, we conclude that hematin and CO induce advantageous effects on the attenuation of salt-stress inhibition of C. obtusifolia seeds and seedlings and alleviate oxidative damage by conferring beneficial cytoprotection and activating anti-oxidant enzymes. 相似文献3.
Aim
In rice, the top two leaves are the major carbohydrate source during grain filling. Physiological performance of these leaves under salinity may allow estimate stress-induced yield loss.Methods
Greenhouse grown rice plants (cv. Taipei 309) were subjected to 10 and 20 mM NaCl stress levels from germination till maturity. Plant development was measured at the flowering stage and yield parameters were quantified after complete ripening of panicles.Results
Gas exchange in the main source leaves were not significantly affected by any of the stress levels. However, growth parameters as well as total metabolizable carbohydrates content, chlorophyll content (CCI), maximal efficiency of PSII photochemistry in dark-adapted state (F v/F m) and lipid peroxidation were significantly affected. Rice yield, measured as total panicle production, declined to 78 and 21 % of controls in 10 and 20 mM NaCl stress, respectively. Stress-induced yield loss was positively related with the decline in CCI, F v/F m and K+/Na+ ratio as well as with the increase in lipid peroxidation and total soluble carbohydrate contents.Conclusions
Though the stress levels used in this work are below what is considered the minimal critical threshold of toxicity for rice, they induce significant negative effects on plant development and yield, when present along the whole plant life cycle. 相似文献4.
Isolation of ACC deaminase producing PGPR from rice rhizosphere and evaluating their plant growth promoting activity under salt stress 总被引:2,自引:0,他引:2
Aims
Bacteria possessing ACC deaminase activity reduce the level of stress ethylene conferring resistance and stimulating growth of plants under various biotic and abiotic stresses. The present study aims at isolating efficient ACC deaminase producing PGPR strains from the rhizosphere of rice plants grown in coastal saline soils and quantifying the effect of potent PGPR isolates on rice seed germination and seedling growth under salinity stress and ethylene production from rice seedlings inoculated with ACC deaminase containing PGPR.Methods
Soils from root region of rice growing in coastal soils of varying salinity were used for isolating ACC deaminase producing bacteria and three bacterial isolates were identified following polyphasic taxonomy. Seed germination, root growth and stress ethylene production in rice seedlings following inoculation with selected PGPR under salt stress were quantified.Results
Inoculation with selected PGPR isolates had considerable positive impacts on different growth parameters of rice including germination percentage, shoot and root growth and chlorophyll content as compared to uninoculated control. Inoculation with the ACC deaminase producing strains reduced ethylene production under salinity stress.Conclusions
This study demonstrates the effectiveness of rhizobacteria containing ACC deaminase for enhancing salt tolerance and consequently improving the growth of rice plants under salt-stress conditions. 相似文献5.
Aims
Seeds of Henophyton deserti (Brassicaceae), an endemic saharan shrub in south Tunisia, produce a pectinaceous mucilage layer that can imbibe a large amount of water when wetted. The aim of this study was to explore the role of mucilage in seed germination of this shrub under heterogeneous stressful environments.Methods
Germination of both intact and demucilaged seeds was tested over wide ranges of temperature, and in iso-osmotic solutions of NaCl and PEG. Recovery of germination after NaCl and Polyethylene Glycol (PEG)-6000 treatment was also tested. The effect of mucilage on water uptake was measured and the structure of the seed investigated.Results
A considerable proportion of seed mass (30 %) is made up of mucilage, which is extremely hydrophilic and able to increase seed mass by 550 % over dry seeds. Mucilage water uptake appears to be unaffected by salt concentration, while higher concentrations of PEG inhibit mucilage hydration. Mucilage decreases germination specifically at 10 °C and this effect can be interpreted in relation to oxygen uptake. High concentrations of NaCl and PEG decrease both germination percentage and rate, with some greater tolerance at 15 °C and 20 °C versus 25 °C. Recovery was higher from higher concentrations of NaCl and PEG and lower temperatures, with a clear inhibitory effect of mucilage.Conclusions
The study has shown that the mucilage of H. deserti may act as a physical barrier for regulating diffusion of water and oxygen to the inner tissue of the seed and thereby prevent germination under unsuitable conditions. 相似文献6.
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Xiao-lin Zhang Guang-lin Liu Tian-lai Li Ming-fang Qi Mei Mei Xiu-jun Lu 《Trees - Structure and Function》2014,28(3):859-870
Key message
This is the first reported proteomic analysis to study the dormancy breaking of Magnolia sieboldii seeds. Our results provide a fundamental reference for further studies on the regulation of protein expression during seed germination.Abstract
Magnolia sieboldii K. Koch is an ornamental tree. The deep dormancy of its seeds hinders its cultivation for economic purposes. The biochemical basis of the regulation of seed germination remains poorly understood. The present study aimed to identify differentially expressed proteins in germinated seeds of M. sieboldii using polyethylene glycol fractionation. In total, 59 differentially expressed protein spots from two-dimensional gel maps were detected, 33 of which were identified by mass spectrometry. They were assigned to eight functional classes on the basis of their putative biological functions: photosynthesis (3 %), chaperonin/heat shock protein (9 %), protein and amino acid synthesis (9 %), stress/defense (18 %), cytoskeleton structure (3 %), metabolism (18 %), hormone and polyamine (9 %) and storage proteins (31 %). Among the other functions, the effects of plant hormones on seed germination may be one of the most important functions in plant growth. Gibberellins and ethylene positively regulate seed germination. The activities of several hormone-associated proteins possibly influencing seed germination were increased. The characterization of these proteins will be of great help in identifying the molecular mechanism underlying seed germination. 相似文献8.
Chunping Zhang Ping He Yicun Li Yan Li Huankai Yao Jingyu Duan Shijun Hu Hui Zhou Shuo Li 《Journal of Plant Growth Regulation》2016,35(2):330-344
The purpose of the present study was to investigate the mechanism of DA-6 in alleviating the salinity inhibition of Cassia obtusifolia L. seeds and seedlings. NaCl (100 mM) was used to mimic salinity stress in a series of experiments. Varying combinations of DA-6 were added to seeds and seedlings under salinity stress. Seed germination indices and seedling parameters were investigated. Seed germination and seedling growth were significantly inhibited under salinity stress. NaCl-induced inhibitory effects on seed germination and seedling growth were ameliorated by DA-6 with different concentrations. Addition of DA-6 to seeds (50 µM) and seedlings (100 µM) significantly alleviated damage to the plant cells under salinity stress. DA-6 (regardless of the presence or absence of NaCl) enhanced chlorophyll concentration, total soluble sugars, free proline, and soluble protein, and improved photosystem II (PSII) photochemical efficiency levels (F v/F m), PSII actual photochemical efficiency (ΦPSII), and the photochemical quench coefficient. In contrast, the initial fluorescence (F o) and the non-photochemical quenching coefficient decreased. Application of DA-6 also enhanced the activities of superoxide dismutase (SOD; EC 1.15.1.1), peroxidase (POD; EC 1.11.1.7), catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APX; EC 1.11.1.11), and glutathione reductase (GR; EC 1.6.4.2), thus alleviating oxidative damage, as indicated by decreases in thiobarbituric acid-reactive substances, hydrogen peroxide concentration (H2O2), relative conductivity, and lipoxygenase activity (LOX; EC 1.13.11.12). Based on the experimental results, we conclude that DA-6 induces advantageous effects on the attenuation of salt-stress inhibition of C. obtusifolia seeds and seedlings and alleviates oxidative damage by conferring beneficial cytoprotection and activating antioxidant enzymes. DA-6 can be used as an effective plant growth regulator to alleviate salinity stress. 相似文献
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Seeds of the halophyte Crithmum maritimum L. were exposed to salt stress and chemical pretreatments in order to improve germination. Seeds submitted to salt stress did not germinate but they recovered rapidly upon transfer to distilled water, recovery being higher after a low salinity pretreatment. Chemical treatments resulted in differential effects on seed germination. Known dormancy breakers such as potassium nitrate and thiourea had no effect on sea fennel seed germination. Conversely, l-ascorbic acid (40 or 60 mM) and ethanol (96%) significantly improved germination rate by 10, 30 and 30%, respectively. Pretreatment of seeds with l-ascorbic acid at 40 mM was shown to alleviate the negative effects of low NaCl concentration on germination. These findings indicate that the application of ascorbic acid may be used to improve sea fennel seed germination, which is of great interest for cultivating this plant. 相似文献
10.
Ya-Lin Hu En-Rong Yan Woo-Jung Choi Francis Salifu Xiao Tan Z. Chi Chen De-Hui Zeng Scott X. Chang 《Plant and Soil》2014,374(1-2):399-409