Seedlings of six Glycine max cultivars were used to compare Cl- with Na+ in stress effects onsoybean seedlings under NaCl stress. Results showed that stress of NaCl on G. max seedlings was mainlycaused by Cl- and not ...Seedlings of six Glycine max cultivars were used to compare Cl- with Na+ in stress effects onsoybean seedlings under NaCl stress. Results showed that stress of NaCl on G. max seedlings was mainlycaused by Cl- and not by Na+. After treatment with isoosmotic solutions of Cl- (without Na+ ) and Na+ (with-out Cl-) respectively, fresh weight and height of G. max seedlings growing in solution of Cl- were much morestressed than those in solution of Na+. And the roots and leaves electrolyte leakage were much more increasedunder stress of Cl- than those under stress of Na+. Salt tolerance of G. max seedlings was mainly contributedto Cl- withheld in roots of seedlings to decrease its content in leaves.展开更多
In this study, a polysaccharide from Enteromorpha prolifera (EP) was extracted and its effect on maize seedlings under NaCl stress was investigated. Firstly, the components and structure of the EP were determined. We ...In this study, a polysaccharide from Enteromorpha prolifera (EP) was extracted and its effect on maize seedlings under NaCl stress was investigated. Firstly, the components and structure of the EP were determined. We found that EP is a sulfated polysaccharide of high-molecular weight (Mw, 1 840 KDa) heteropolysaccharides and the main monosaccharide is rhamnose. The polysaccharide was applied to explore its effect on the growth of maize seedlings and its defense response under a salt stress. The results show that EP could promote the growth of maize seedlings under the salt stress. In addition, EP was shown able to significantly regulate membrane permeability and adjustment of osmotic substances such as soluble protein, soluble sugar, and proline, antioxidant enzymes containing superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase. Therefore, EP is an effective salt-resistant substance for the growth of maize seedlings under NaCl stress.展开更多
In order to explore the salt-tolerance of Narcissus pseudonarcissus and enrich its cultivation and application forms. In this experiment, “Manly”, “Dutch” and “Wilden” daffodils were used as test materials. NaCl...In order to explore the salt-tolerance of Narcissus pseudonarcissus and enrich its cultivation and application forms. In this experiment, “Manly”, “Dutch” and “Wilden” daffodils were used as test materials. NaCl stress was applied at different concentrations, and the corresponding physiological indexes were measured at three time nodes: bolting stage, early flowering stage and blooming stage. The results showed that all three showed some resistance under low concentration salt stress, in which, SOD, POD enzyme activity, chlorophyll proline and soluble sugar content increased, while MDA content decreased. The physiological metabolism of the three was disturbed under high concentration of salt stress, in which, SOD, POD enzyme activity and chlorophyll content decreased, while MDA, proline and soluble sugar content increased. With the extension of stress time, the injury was gradually deepened and the salt tolerance of the three varieties is “Dutch”, “Wilden” and “Manly” in order.展开更多
[Objective] The paper was to study effects of different salt treatments on growth and physiological activity of sunflower seedlings,in order to provide a theoretical basis for sunflower cultivation in saline soil. [Me...[Objective] The paper was to study effects of different salt treatments on growth and physiological activity of sunflower seedlings,in order to provide a theoretical basis for sunflower cultivation in saline soil. [Method] With 567 DW sunflower as the material,effects of different concentrations of NaCl (0,0.06,0.12,0.18,0.24 mol/L) on growth and physiological activity of sunflower seedlings were studied. [Result]With the increasing concentration of NaCl,the morphological indexes of sunflower decreased significantly; MDA content increased,while Pro content and POD activity first increased and then decreased. Under the treatment of 0.12 mol/L,Pro content and POD activity reached the maximum value,respectively. [Conclusion] The critical salt-tolerance concentration of sunflower was about 0.12 mol/L.展开更多
Background:Recently,due to the development of food security strategies,cotton has been planted in inland saline-alkali dry soils or in coastal some saline-alkali soils in China.Under the condition,to comprehensively p...Background:Recently,due to the development of food security strategies,cotton has been planted in inland saline-alkali dry soils or in coastal some saline-alkali soils in China.Under the condition,to comprehensively prevent and control Helicoverpa armigera in cotton fields with saline-alkali soils,it is important to study the larval growth and development of H.armigero and to study adult oviposition selectivity in H.armigera adults that feed on NaCI-stNaCled cotton plants.Results:In this study,Bt cotton GK19 was used for the experimental group and its nontransgenic parent Simian 3 was used for the control to study the effects of biochemical substances in cotton as well as larval growth and development and adult oviposition selectivity of H.armigera.The experiments were performed by growing cotton indoors under NaCl stress at concentrations of 0 mmol-L-1,75 mmol-L-1 and 150 mmol-L-1,respectively.The results showed that the expression of Bt protein was significantly inhibited for NaCI-stressed Bt cotNaClThe content of soluble protein and K+ in the leaves of cotton were decreased,while the content of gossypol and Na+were increased.In addition,the 5th instar H.armigera larvae exhibited shorten the life span in a 13-day trial period.Under enclosure treatments and at different female densities,the adult oviposition of H.armigera decreased on high NaCI-stressed nontransgenic coNaCl,while the oviposition on Bt cotton tended to first increase but then decrease under low,moderate and high NaCl stress treatments.Conclusions:Under certain content ranges of NaCl stress treatments,larval of H.armigera growth and development,and adult oviposition were no significant difference in the change for a certain period.However,under high NaCl stress,larval growth,development and adult oviposition were affected,which may provide insights for the prevention and control of H.armigero for Bt cotton in saline-alkali soils.展开更多
The changes in growth status, ion contents, betaine levels and betaine\|aldehyde dehydrogenase (BADH) activity in seedlings of nonhalophyte barley treated with different concentrations of NaCl and KCl were studied. Re...The changes in growth status, ion contents, betaine levels and betaine\|aldehyde dehydrogenase (BADH) activity in seedlings of nonhalophyte barley treated with different concentrations of NaCl and KCl were studied. Results showed that the inhibition of growth in barley seedlings increased as enhancing NaCl and KCl for 96h and NaCl inhibitory degree was higher than that of KCl. The K\++ content of barley seedlings in NaCl was lower than the control, while the Na\++ content was higher, the levels of Na\++ fell in the seedlings treated with KCl, but K\++ levels rose, and K\++ content was higher than that of Na\++. The betaine levels of barley shoots rose with the increase in both external salt concentration and treatment time. Higher BADH activity was observed in low\|salt concentration but lower slightly in high\|salt concentration.展开更多
Growth and osmotic response of Lactobacillus bulgaricus ATCC 11842 under hyperosmotic constraint were investigated in a chemically defined medium (CDM) and MRS medium. NaCl could inhibit the growth of L. bulgaricus wh...Growth and osmotic response of Lactobacillus bulgaricus ATCC 11842 under hyperosmotic constraint were investigated in a chemically defined medium (CDM) and MRS medium. NaCl could inhibit the growth of L. bulgaricus which decreased with increasing NaCl concentration. In the MRS, NaCl of 1.0 mol·L-1 was the biggest salt stress concentration; in the CDM, 0.8 mol·L-1 was the biggest inhibition concentration. In contrast to what was observed in other lactic acid bacteria, proline, glycine betaine and related molecules were unable to relieve inhibition of growth of L. bulgaricus under osmotic constraint. This was correlated to the absence of sequences homologous to the genes coding for glycine-betaine and/or proline transporters described in Lactococcus lactis and Bacillus subtilis. The amino acid aspartate and alanine were proved to be osmoprotective under NaCl stress. Addition of peptone (0.25% w/v) in the presence of salt led to a stimulation of the growth, as the decrease of the lag time and generation time, and the final biomass increased from 0.31 to 0.64.展开更多
The solution culture method was used to study the effect of increasing nitrogen on the growth and pho-tosynthesis of poplar seedlings under 100 mmol L-1 NaCl stress. I Increase in nitrogen reduced stomatal limitation ...The solution culture method was used to study the effect of increasing nitrogen on the growth and pho-tosynthesis of poplar seedlings under 100 mmol L-1 NaCl stress. I Increase in nitrogen reduced stomatal limitation of leaves under NaCl stress, improved utilization of CO2 by mesophyll cells, enhanced photosynthetic carbon assimi-lation capacity, significantly alleviated saline damage of NaCl, and promoted the accumulation of aboveground and root biomass. I Increased nitrogen enhanced photochemical efficiency (ΦPSⅡ) and electron transport rates, relieved the reduction of maximum photochemical efficiency (Fv/Fm) under NaCl, and reduced the degree of photoinhibition caused by NaCl stress. Increased nitrogen applications reduced the proportion of energy dissipating in the form of ineffective heat energy and hence a greater proportion of light energy absorbed by leaves was allocated to photo-chemical reactions. Under treatment with increased nitro-gen, the synergistic effect of heat dissipation and the xanthophyll cycle in the leaves effectively protected pho-tosynthetic PSⅡ and enhanced light energy utilization of leaves under NaCl stress. The increased nitrogen promoted photosynthetic electron supply and transport ability under NaCl stress evident in enhanced functioning of the oxygen-evolving complex on the electron donor side of PS Ⅱ. It increased the ability of the receptor pool to accept electrons on the PSII electron acceptor side and improved the sta-bility of thylakoid membranes under NaCl stress. Therefore, increasing nitrogen applications under NaCl stress can promote poplar growth by improving the effi-ciency of light energy utilization.展开更多
Many species of microalga Dunaliella exhibit a remarkable tolerance to salinity and are therefore ideal for probing the effects of salinity. In this work, we assessed the effects of NaCl stress on the growth, activity...Many species of microalga Dunaliella exhibit a remarkable tolerance to salinity and are therefore ideal for probing the effects of salinity. In this work, we assessed the effects of NaCl stress on the growth, activity and m RNA level of carbon and nitrogen metabolism enzymes of D. viridis. The alga could grow over a salinity range of 0.44 mol L^(-1) to 3.00 mol L^(-1) NaCl, but the most rapid growth was observed at 1.00 mol L^(-1) NaCl, followed by 2.00 mol L^(-1) NaCl. Paralleling these growth patterns, the highest initial and total Rubisco activities were detected in the presence of 1.00 mol L^(-1) NaCl, decreasing to 37.33% and 26.39% of those values, respectively, in the presence of 3.00 mol L^(-1) Na Cl, respectively. However, the highest extracellular carbonic anhydrase(CA) activity was measured in the presence of 2.00 mol L^(-1) NaCl, followed by 1.00 mol L^(-1) NaCl. Different from the two carbon enzymes, nitrate reductase(NR) activity showed a slight change under different NaCl concentrations. At the transcriptional level, the m RNAs of Rubisco large subunit(rbcL), and small subunit(rbc S), attained their highest abundances in the presence of 1.00 and 2.00 mol L^(-1)NaCl, respectively. The CA mRNA accumulation was induced from 0.44 mol L^(-1) to 3.00 mol L^(-1) NaCl, but the NR m RNA showed the decreasing tendency with the increasing salinity. In conclusion, the growth and carbon fixation enzyme of Rubisco displayed similar tendency in response to NaCl stress, CA was proved be salt-inducible within a certain salinity range and NR showed the least effect by NaCl in D. viridis.展开更多
For a plant species to complete its life cycle in arid and saline environments,each stage of the life cycle must be tolerant to the harsh environmental conditions.The aim of the study was to determine the effects of w...For a plant species to complete its life cycle in arid and saline environments,each stage of the life cycle must be tolerant to the harsh environmental conditions.The aim of the study was to determine the effects of water stress(water potentials of–0.05,–0.16,–0.33,–0.56,–0.85 and–1.21 MPa)and NaCl stress(50,100,200,300,400,500 and 600 mmol/L NaCl)on seed germination percentage,seedling survival and growth,juvenile growth and plant reproduction of Lachnoloma lehmannii Bunge(Brassicaceae),an cold desert annual that grows in the Junggar Basin of Xinjiang,China in 2010.Results indicated that low water stress(–0.05 and–0.16 MPa)had no significant effect on seed germination percentage.With a decrease in water potential,germination percentage decreased,and no seeds germinated at–0.85 and–1.21 MPa water stresses.Germination percentage of seeds was significantly affected by NaCl stress,and higher germination percentages were observed under non-saline than saline conditions.An increase in NaCl concentrations progressively inhibited seed germination percentage,and no seeds germinated at ≥400 mmol/L NaCl concentration.Non-germinated seeds were transferred from both PEG(polyethylene glycol-6000)and NaCl solutions to distilled water for seed germination recovery.The number of surviving seedlings and their heights and root lengths significantly decreased as NaCl stress increased.About 30% of the plants survived and produced fruits/seeds at 200 mmol/L NaCl concentration.Thus,seed germination,seedling establishment and reproductive stage in the life cycle of L.lehmannii are water-and salt-tolerant,with seedlings being the least tolerant.These tolerances help explain why this species can survive and produce seeds in arid and saline habitats.展开更多
Employing nutrient solution hydroponic method,the effects of exogenous nitric oxide(NO)on the growth and active oxygen metabolism in cucumber(Cucumis sativus L.)seedlings under NaCl stress were investigated.The result...Employing nutrient solution hydroponic method,the effects of exogenous nitric oxide(NO)on the growth and active oxygen metabolism in cucumber(Cucumis sativus L.)seedlings under NaCl stress were investigated.The results indicated that NaCl treatment significantly inhibited the growth of cucumber seedlings,while exogenous NO could significantly alleviate the inhibitory effects of NaCl stress on seedling growth.Especially,0.1 mmol/L SNP treatment exhibited better effects than 0.5 mmol/L SNP treatment on alleviating NaCl stress.Under 0.1 mmol/L NaCl stress,adding 0.1 mmol/L exogenous NO could significantly decrease the generation rate of O·-2and MDA content,significantly improve soluble protein content and enhance the activities of SOD,POD and CAT,thus reducing the damage of salt stress to cucumber seedlings.展开更多
Salinity is one of the most serious growth limiting factor, therefore, no longer being ignored. Although, cotton is fairly salt tolerant;its sensitivity at crop stand and yield is affected. This study is planned to id...Salinity is one of the most serious growth limiting factor, therefore, no longer being ignored. Although, cotton is fairly salt tolerant;its sensitivity at crop stand and yield is affected. This study is planned to identify the growth, physiological and molecular parameters in local cotton varieties FDH 171 and FDH 786 under NaCl stress. There was 100% seed germination but hypocotyl length was reduced at increasing level of NaCl. Plant height, fresh and dry biomass were reduced as the plants were subjected to increased stress of NaCl. Stomatal conductance, transpiration and photosynthetic rate and ionic imbalance were found to be reduced under the gradual increase in NaCl stress and affected the plant’s overall physiological processes. PCR product of AtNHX3 has been identified in stressed and non-stressed plants. Thus, the genotypes FDH 171 & FDH 786 were found tolerant to adoption of salt stress and could be used as a source in crop improvement.展开更多
High level of salinity adversely affects growth, productivity as well as quality of vegetable crops by reducing photosynthetic capacity, enzyme activities, and by enhanced production of reactive oxygen species (ROS). ...High level of salinity adversely affects growth, productivity as well as quality of vegetable crops by reducing photosynthetic capacity, enzyme activities, and by enhanced production of reactive oxygen species (ROS). These ROS cause peroxidation of membrane lipids leading to disintegration of cell membrane with the leakage of electrolytes. All these detrimental effects ultimately contribute to the crop with reduced yield and low nutritive value. The present investigation was carried out to test salt tolerance capacity of ten genotypes of tomato on the basis of growth, physiological and biochemical characteristics. The results show that all the ten tested genotypes of tomato responded differently to 200 mM NaCl stress. Regarding growth parameters, BL-1076 gave higher values, while Queen gave the lowest values for most of the parameters (plant height, number of leaves, leaf area, shoot and root fresh weight and dry weight). Regarding physiological and biochemical parameters, BL-1076 gave higher values for the activities of carbonic anhydrase and nitrate reductase, leaf chlorophyll content, relative water content, and activities of antioxidant enzymes (superoxide dismutase, peroxidase and catalase). However, genotype Queen gave the lowest values for these parameters. On contrary, the least membrane damage (TBARS content) was registered in BL-1076, while the highest in Queen. Overall assessment of results leads to the conclusion that the genotype BL-1076 was found salt tolerant while Queen salt sensitive. The ten genotypes may be arranged on the basis of their salt tolerance capacity in decreasing order as: BL-1076 > Trust > Imperial > Tanshet star > PakmoreVF > L 26 > Plitz > Bonus F1 > Grace > Queen.展开更多
Populus x canescens was cultivated on solid substrate and treated by salt (150 mM NaCl). The growth parameters including new leaf formation, height increment, diameter at the base increment, fresh and dry mass of leaf...Populus x canescens was cultivated on solid substrate and treated by salt (150 mM NaCl). The growth parameters including new leaf formation, height increment, diameter at the base increment, fresh and dry mass of leaf, stem, coarse root, and fine root were determined. The nutrient elements in leaves of samples under salt stress and the control, and the chlorophyll fluorescence of plants separated dark and light, initial fluorescence (Fo), and maximum fluorescence (Fm) were measured. Results showed that 150 mM NaCl treatment resulted in growth reduction of Populus x canescens. Nutrient element contents in the foliage of plants under salt stress were different from that of control. The foliar N-concentrations of plants under salt stress were not affected. Contents of Na under salt stress were 120 times as much as that under control. However, contents of S, K, P, Ca, Mg, Fe, Mn under salt stress were less than that under control. Salt stress caused damage in the PSII reaction centers, i.e. photo-inhibition couldn’t be repaired under dark situation. The yield of chlorophyll fluorescence showed that several parameters associated with PSII functions, e.g. Fv/Fo, Fv/Fm were not influenced at the first stage of salt stress treatment. However, after a period of time, PSII functions were significantly inhibited, which led to the decrease of carbon assimilation. These results suggest that salt stress (150 mM NaCl) did not affect photosynthetic chlorophyll fluorescence of Populus x canescens immediately. After four day of salt stress, PSII reaction centres were seriously damaged during photo-inhibition.展开更多
Salt stress is a major abiotic stress limiting plant growth and yield. In the present study, the effects of exogenous H_(2)O_(2) on the reactive oxygen species(ROS) metabolism and the antioxidant system in leaves of N...Salt stress is a major abiotic stress limiting plant growth and yield. In the present study, the effects of exogenous H_(2)O_(2) on the reactive oxygen species(ROS) metabolism and the antioxidant system in leaves of Nitralia tangutorum Bobr. under salt stress were studied. N. tangutorum seedlings were subjected to 200 mmol·L^(-1) NaCl treatment with or without the exogenous application of H_(2)O_(2) for 7 days. The results showed that NaCl stress significantly increased the relative conductivity, the contents of thiobarbituric acid reactive substances(TBARS) and ROS(H_(2)O_(2) and O_(2)^(·-)), as well as promoted the activities of antioxidant enzymes including superoxide dismutase(SOD), peroxidase(POD), catalase(CAT), and ascorbate peroxidase(APX) in N. tangutorum leaves. In addition, exogenous H_(2)O_(2) decreased the relative conductivity, the contents of TBARS, H_(2)O_(2) and O_(2)^(·-), while further enhanced the activities of antioxidant enzymes. These results indicated that H_(2)O_(2) effectively alleviated the adverse effects of NaCl stress on N. tangutorum through the regulation of ROS metabolism.展开更多
基金the Scientific Foundation Special for Ph D Programs in Chinese Universities (1999002005) National Natural Science Foundation of China (39870069) the International Foundation for Science (C/3143-1), China.
文摘Seedlings of six Glycine max cultivars were used to compare Cl- with Na+ in stress effects onsoybean seedlings under NaCl stress. Results showed that stress of NaCl on G. max seedlings was mainlycaused by Cl- and not by Na+. After treatment with isoosmotic solutions of Cl- (without Na+ ) and Na+ (with-out Cl-) respectively, fresh weight and height of G. max seedlings growing in solution of Cl- were much morestressed than those in solution of Na+. And the roots and leaves electrolyte leakage were much more increasedunder stress of Cl- than those under stress of Na+. Salt tolerance of G. max seedlings was mainly contributedto Cl- withheld in roots of seedlings to decrease its content in leaves.
基金Supported by the Commonweal Item of State Oceanic Administration of the People’s Republic of China(No.201505033)the Shandong Province Key Research and Development Project(No.2017GHY215008)the Qingdao Science and Technology Project(No.17-3-3-60-nsh)
文摘In this study, a polysaccharide from Enteromorpha prolifera (EP) was extracted and its effect on maize seedlings under NaCl stress was investigated. Firstly, the components and structure of the EP were determined. We found that EP is a sulfated polysaccharide of high-molecular weight (Mw, 1 840 KDa) heteropolysaccharides and the main monosaccharide is rhamnose. The polysaccharide was applied to explore its effect on the growth of maize seedlings and its defense response under a salt stress. The results show that EP could promote the growth of maize seedlings under the salt stress. In addition, EP was shown able to significantly regulate membrane permeability and adjustment of osmotic substances such as soluble protein, soluble sugar, and proline, antioxidant enzymes containing superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase. Therefore, EP is an effective salt-resistant substance for the growth of maize seedlings under NaCl stress.
文摘In order to explore the salt-tolerance of Narcissus pseudonarcissus and enrich its cultivation and application forms. In this experiment, “Manly”, “Dutch” and “Wilden” daffodils were used as test materials. NaCl stress was applied at different concentrations, and the corresponding physiological indexes were measured at three time nodes: bolting stage, early flowering stage and blooming stage. The results showed that all three showed some resistance under low concentration salt stress, in which, SOD, POD enzyme activity, chlorophyll proline and soluble sugar content increased, while MDA content decreased. The physiological metabolism of the three was disturbed under high concentration of salt stress, in which, SOD, POD enzyme activity and chlorophyll content decreased, while MDA, proline and soluble sugar content increased. With the extension of stress time, the injury was gradually deepened and the salt tolerance of the three varieties is “Dutch”, “Wilden” and “Manly” in order.
基金Supported by National Natural Science Funds for Distinguished Young Scholar"Effect of Se and Its Accumulation on Sunflower in the Saline-alkali"(31301851)
文摘[Objective] The paper was to study effects of different salt treatments on growth and physiological activity of sunflower seedlings,in order to provide a theoretical basis for sunflower cultivation in saline soil. [Method] With 567 DW sunflower as the material,effects of different concentrations of NaCl (0,0.06,0.12,0.18,0.24 mol/L) on growth and physiological activity of sunflower seedlings were studied. [Result]With the increasing concentration of NaCl,the morphological indexes of sunflower decreased significantly; MDA content increased,while Pro content and POD activity first increased and then decreased. Under the treatment of 0.12 mol/L,Pro content and POD activity reached the maximum value,respectively. [Conclusion] The critical salt-tolerance concentration of sunflower was about 0.12 mol/L.
基金financial support from the National Natural Science Foundation of China(31501253)
文摘Background:Recently,due to the development of food security strategies,cotton has been planted in inland saline-alkali dry soils or in coastal some saline-alkali soils in China.Under the condition,to comprehensively prevent and control Helicoverpa armigera in cotton fields with saline-alkali soils,it is important to study the larval growth and development of H.armigero and to study adult oviposition selectivity in H.armigera adults that feed on NaCI-stNaCled cotton plants.Results:In this study,Bt cotton GK19 was used for the experimental group and its nontransgenic parent Simian 3 was used for the control to study the effects of biochemical substances in cotton as well as larval growth and development and adult oviposition selectivity of H.armigera.The experiments were performed by growing cotton indoors under NaCl stress at concentrations of 0 mmol-L-1,75 mmol-L-1 and 150 mmol-L-1,respectively.The results showed that the expression of Bt protein was significantly inhibited for NaCI-stressed Bt cotNaClThe content of soluble protein and K+ in the leaves of cotton were decreased,while the content of gossypol and Na+were increased.In addition,the 5th instar H.armigera larvae exhibited shorten the life span in a 13-day trial period.Under enclosure treatments and at different female densities,the adult oviposition of H.armigera decreased on high NaCI-stressed nontransgenic coNaCl,while the oviposition on Bt cotton tended to first increase but then decrease under low,moderate and high NaCl stress treatments.Conclusions:Under certain content ranges of NaCl stress treatments,larval of H.armigera growth and development,and adult oviposition were no significant difference in the change for a certain period.However,under high NaCl stress,larval growth,development and adult oviposition were affected,which may provide insights for the prevention and control of H.armigero for Bt cotton in saline-alkali soils.
文摘The changes in growth status, ion contents, betaine levels and betaine\|aldehyde dehydrogenase (BADH) activity in seedlings of nonhalophyte barley treated with different concentrations of NaCl and KCl were studied. Results showed that the inhibition of growth in barley seedlings increased as enhancing NaCl and KCl for 96h and NaCl inhibitory degree was higher than that of KCl. The K\++ content of barley seedlings in NaCl was lower than the control, while the Na\++ content was higher, the levels of Na\++ fell in the seedlings treated with KCl, but K\++ levels rose, and K\++ content was higher than that of Na\++. The betaine levels of barley shoots rose with the increase in both external salt concentration and treatment time. Higher BADH activity was observed in low\|salt concentration but lower slightly in high\|salt concentration.
基金Supported by the National Natural Science Funds (31201397)Science Fund for Distinguished Young Scholars Program for Changjiang Scholars and Innovative Research Team in University (IRT0959)Doctor Start Fund of Northeast Agricultural University (2010RCB59)
文摘Growth and osmotic response of Lactobacillus bulgaricus ATCC 11842 under hyperosmotic constraint were investigated in a chemically defined medium (CDM) and MRS medium. NaCl could inhibit the growth of L. bulgaricus which decreased with increasing NaCl concentration. In the MRS, NaCl of 1.0 mol·L-1 was the biggest salt stress concentration; in the CDM, 0.8 mol·L-1 was the biggest inhibition concentration. In contrast to what was observed in other lactic acid bacteria, proline, glycine betaine and related molecules were unable to relieve inhibition of growth of L. bulgaricus under osmotic constraint. This was correlated to the absence of sequences homologous to the genes coding for glycine-betaine and/or proline transporters described in Lactococcus lactis and Bacillus subtilis. The amino acid aspartate and alanine were proved to be osmoprotective under NaCl stress. Addition of peptone (0.25% w/v) in the presence of salt led to a stimulation of the growth, as the decrease of the lag time and generation time, and the final biomass increased from 0.31 to 0.64.
基金supported by the Fundamental Research Funds for the Central Universities(2572018BE05)the National Natural Science Foundation of China(3150032331370426)
文摘The solution culture method was used to study the effect of increasing nitrogen on the growth and pho-tosynthesis of poplar seedlings under 100 mmol L-1 NaCl stress. I Increase in nitrogen reduced stomatal limitation of leaves under NaCl stress, improved utilization of CO2 by mesophyll cells, enhanced photosynthetic carbon assimi-lation capacity, significantly alleviated saline damage of NaCl, and promoted the accumulation of aboveground and root biomass. I Increased nitrogen enhanced photochemical efficiency (ΦPSⅡ) and electron transport rates, relieved the reduction of maximum photochemical efficiency (Fv/Fm) under NaCl, and reduced the degree of photoinhibition caused by NaCl stress. Increased nitrogen applications reduced the proportion of energy dissipating in the form of ineffective heat energy and hence a greater proportion of light energy absorbed by leaves was allocated to photo-chemical reactions. Under treatment with increased nitro-gen, the synergistic effect of heat dissipation and the xanthophyll cycle in the leaves effectively protected pho-tosynthetic PSⅡ and enhanced light energy utilization of leaves under NaCl stress. The increased nitrogen promoted photosynthetic electron supply and transport ability under NaCl stress evident in enhanced functioning of the oxygen-evolving complex on the electron donor side of PS Ⅱ. It increased the ability of the receptor pool to accept electrons on the PSII electron acceptor side and improved the sta-bility of thylakoid membranes under NaCl stress. Therefore, increasing nitrogen applications under NaCl stress can promote poplar growth by improving the effi-ciency of light energy utilization.
基金funded by the Project of Science and Technology Innovation Team of Zhejiang Province (2010R50025-25)sponsored by the K. C. Wong Magna Fund
文摘Many species of microalga Dunaliella exhibit a remarkable tolerance to salinity and are therefore ideal for probing the effects of salinity. In this work, we assessed the effects of NaCl stress on the growth, activity and m RNA level of carbon and nitrogen metabolism enzymes of D. viridis. The alga could grow over a salinity range of 0.44 mol L^(-1) to 3.00 mol L^(-1) NaCl, but the most rapid growth was observed at 1.00 mol L^(-1) NaCl, followed by 2.00 mol L^(-1) NaCl. Paralleling these growth patterns, the highest initial and total Rubisco activities were detected in the presence of 1.00 mol L^(-1) NaCl, decreasing to 37.33% and 26.39% of those values, respectively, in the presence of 3.00 mol L^(-1) Na Cl, respectively. However, the highest extracellular carbonic anhydrase(CA) activity was measured in the presence of 2.00 mol L^(-1) NaCl, followed by 1.00 mol L^(-1) NaCl. Different from the two carbon enzymes, nitrate reductase(NR) activity showed a slight change under different NaCl concentrations. At the transcriptional level, the m RNAs of Rubisco large subunit(rbcL), and small subunit(rbc S), attained their highest abundances in the presence of 1.00 and 2.00 mol L^(-1)NaCl, respectively. The CA mRNA accumulation was induced from 0.44 mol L^(-1) to 3.00 mol L^(-1) NaCl, but the NR m RNA showed the decreasing tendency with the increasing salinity. In conclusion, the growth and carbon fixation enzyme of Rubisco displayed similar tendency in response to NaCl stress, CA was proved be salt-inducible within a certain salinity range and NR showed the least effect by NaCl in D. viridis.
基金supported by the National Basic Research Program of China(2014CB954202)the National Natural Science Foundation of China(31460128,U1603231,31760060)
文摘For a plant species to complete its life cycle in arid and saline environments,each stage of the life cycle must be tolerant to the harsh environmental conditions.The aim of the study was to determine the effects of water stress(water potentials of–0.05,–0.16,–0.33,–0.56,–0.85 and–1.21 MPa)and NaCl stress(50,100,200,300,400,500 and 600 mmol/L NaCl)on seed germination percentage,seedling survival and growth,juvenile growth and plant reproduction of Lachnoloma lehmannii Bunge(Brassicaceae),an cold desert annual that grows in the Junggar Basin of Xinjiang,China in 2010.Results indicated that low water stress(–0.05 and–0.16 MPa)had no significant effect on seed germination percentage.With a decrease in water potential,germination percentage decreased,and no seeds germinated at–0.85 and–1.21 MPa water stresses.Germination percentage of seeds was significantly affected by NaCl stress,and higher germination percentages were observed under non-saline than saline conditions.An increase in NaCl concentrations progressively inhibited seed germination percentage,and no seeds germinated at ≥400 mmol/L NaCl concentration.Non-germinated seeds were transferred from both PEG(polyethylene glycol-6000)and NaCl solutions to distilled water for seed germination recovery.The number of surviving seedlings and their heights and root lengths significantly decreased as NaCl stress increased.About 30% of the plants survived and produced fruits/seeds at 200 mmol/L NaCl concentration.Thus,seed germination,seedling establishment and reproductive stage in the life cycle of L.lehmannii are water-and salt-tolerant,with seedlings being the least tolerant.These tolerances help explain why this species can survive and produce seeds in arid and saline habitats.
基金Supported by Independent Innovation Project of Jiangsu Province[CX(11)1005]Nanjing Science and Technology Development Project(2011ZD006)
文摘Employing nutrient solution hydroponic method,the effects of exogenous nitric oxide(NO)on the growth and active oxygen metabolism in cucumber(Cucumis sativus L.)seedlings under NaCl stress were investigated.The results indicated that NaCl treatment significantly inhibited the growth of cucumber seedlings,while exogenous NO could significantly alleviate the inhibitory effects of NaCl stress on seedling growth.Especially,0.1 mmol/L SNP treatment exhibited better effects than 0.5 mmol/L SNP treatment on alleviating NaCl stress.Under 0.1 mmol/L NaCl stress,adding 0.1 mmol/L exogenous NO could significantly decrease the generation rate of O·-2and MDA content,significantly improve soluble protein content and enhance the activities of SOD,POD and CAT,thus reducing the damage of salt stress to cucumber seedlings.
文摘Salinity is one of the most serious growth limiting factor, therefore, no longer being ignored. Although, cotton is fairly salt tolerant;its sensitivity at crop stand and yield is affected. This study is planned to identify the growth, physiological and molecular parameters in local cotton varieties FDH 171 and FDH 786 under NaCl stress. There was 100% seed germination but hypocotyl length was reduced at increasing level of NaCl. Plant height, fresh and dry biomass were reduced as the plants were subjected to increased stress of NaCl. Stomatal conductance, transpiration and photosynthetic rate and ionic imbalance were found to be reduced under the gradual increase in NaCl stress and affected the plant’s overall physiological processes. PCR product of AtNHX3 has been identified in stressed and non-stressed plants. Thus, the genotypes FDH 171 & FDH 786 were found tolerant to adoption of salt stress and could be used as a source in crop improvement.
文摘High level of salinity adversely affects growth, productivity as well as quality of vegetable crops by reducing photosynthetic capacity, enzyme activities, and by enhanced production of reactive oxygen species (ROS). These ROS cause peroxidation of membrane lipids leading to disintegration of cell membrane with the leakage of electrolytes. All these detrimental effects ultimately contribute to the crop with reduced yield and low nutritive value. The present investigation was carried out to test salt tolerance capacity of ten genotypes of tomato on the basis of growth, physiological and biochemical characteristics. The results show that all the ten tested genotypes of tomato responded differently to 200 mM NaCl stress. Regarding growth parameters, BL-1076 gave higher values, while Queen gave the lowest values for most of the parameters (plant height, number of leaves, leaf area, shoot and root fresh weight and dry weight). Regarding physiological and biochemical parameters, BL-1076 gave higher values for the activities of carbonic anhydrase and nitrate reductase, leaf chlorophyll content, relative water content, and activities of antioxidant enzymes (superoxide dismutase, peroxidase and catalase). However, genotype Queen gave the lowest values for these parameters. On contrary, the least membrane damage (TBARS content) was registered in BL-1076, while the highest in Queen. Overall assessment of results leads to the conclusion that the genotype BL-1076 was found salt tolerant while Queen salt sensitive. The ten genotypes may be arranged on the basis of their salt tolerance capacity in decreasing order as: BL-1076 > Trust > Imperial > Tanshet star > PakmoreVF > L 26 > Plitz > Bonus F1 > Grace > Queen.
基金This study was supported by the Major State Basic Research Development Program of China (Grant No. 1999016003).
文摘Populus x canescens was cultivated on solid substrate and treated by salt (150 mM NaCl). The growth parameters including new leaf formation, height increment, diameter at the base increment, fresh and dry mass of leaf, stem, coarse root, and fine root were determined. The nutrient elements in leaves of samples under salt stress and the control, and the chlorophyll fluorescence of plants separated dark and light, initial fluorescence (Fo), and maximum fluorescence (Fm) were measured. Results showed that 150 mM NaCl treatment resulted in growth reduction of Populus x canescens. Nutrient element contents in the foliage of plants under salt stress were different from that of control. The foliar N-concentrations of plants under salt stress were not affected. Contents of Na under salt stress were 120 times as much as that under control. However, contents of S, K, P, Ca, Mg, Fe, Mn under salt stress were less than that under control. Salt stress caused damage in the PSII reaction centers, i.e. photo-inhibition couldn’t be repaired under dark situation. The yield of chlorophyll fluorescence showed that several parameters associated with PSII functions, e.g. Fv/Fo, Fv/Fm were not influenced at the first stage of salt stress treatment. However, after a period of time, PSII functions were significantly inhibited, which led to the decrease of carbon assimilation. These results suggest that salt stress (150 mM NaCl) did not affect photosynthetic chlorophyll fluorescence of Populus x canescens immediately. After four day of salt stress, PSII reaction centres were seriously damaged during photo-inhibition.
基金Supported by the Natural Science Foundation of Heilongjiang Province(LH2019C021)。
文摘Salt stress is a major abiotic stress limiting plant growth and yield. In the present study, the effects of exogenous H_(2)O_(2) on the reactive oxygen species(ROS) metabolism and the antioxidant system in leaves of Nitralia tangutorum Bobr. under salt stress were studied. N. tangutorum seedlings were subjected to 200 mmol·L^(-1) NaCl treatment with or without the exogenous application of H_(2)O_(2) for 7 days. The results showed that NaCl stress significantly increased the relative conductivity, the contents of thiobarbituric acid reactive substances(TBARS) and ROS(H_(2)O_(2) and O_(2)^(·-)), as well as promoted the activities of antioxidant enzymes including superoxide dismutase(SOD), peroxidase(POD), catalase(CAT), and ascorbate peroxidase(APX) in N. tangutorum leaves. In addition, exogenous H_(2)O_(2) decreased the relative conductivity, the contents of TBARS, H_(2)O_(2) and O_(2)^(·-), while further enhanced the activities of antioxidant enzymes. These results indicated that H_(2)O_(2) effectively alleviated the adverse effects of NaCl stress on N. tangutorum through the regulation of ROS metabolism.
