Spartina alterniflora invasions seriously threaten the structure and functions of coastal wetlands in China.In this study,the Suaeda salsa community in the Yellow River Estuary wetland was monitored using long-term La...Spartina alterniflora invasions seriously threaten the structure and functions of coastal wetlands in China.In this study,the Suaeda salsa community in the Yellow River Estuary wetland was monitored using long-term Landsat satellite images acquired from 1997 to 2020 to quantify the impact of changes in hydrological connectivity induced by S.alterniflora on neighboring vegetation com-munities.The results showed that S.alterniflora rapidly expanded in the estuary area at a rate of 4.91 km^(2)/yr from 2010 to 2020.At the same time,the hydrological connectivity of the area and the distribution of S.salsa changed significantly.Small tidal creeks dominated the S.alterniflora landscape.The number of tidal creeks increased significantly,but their average length decreased and they tended to develop in a horizontal tree-like pattern.Affected by the changes in hydrological connectivity due to the S.alterniflora invasion,the area of S.salsa decreased by 41.1%,and the degree of landscape fragmentation increased from 1997 to 2020.Variations in the Largest Patch Index(LPI)indicated that the S.alterniflora landscape had become the dominant landscape type in the Yellow River Estuary.The res-ults of standard deviation ellipse(SDE)and Pearson’s correlation analyses indicated that a well-developed hydrological connectivity could promote the maintenance of the S.salsa landscape.The degradation of most S.salsa communities is caused by the influence of S.alterniflora on the morphological characteristics of the hydrological connectivity of tidal creek systems.展开更多
[Objective] Under salt stress condition,effects of inoculation of arbuscular mycorrhizal fungi Glomus mosseae on SOD and CAT activity in Suaeda salsa seedlings under salt stress were studied.[Method]There were 2 NaCl ...[Objective] Under salt stress condition,effects of inoculation of arbuscular mycorrhizal fungi Glomus mosseae on SOD and CAT activity in Suaeda salsa seedlings under salt stress were studied.[Method]There were 2 NaCl levels,namely 0 and 400 mmol/L and each NaCl contained 2 treatments,one is inoculated by Glomus mosseae and the other is control.The growths of Suaeda salsa,SOD and CAT activities as well as MDA content in leaves was determined.[Result]Under salt stress condition,Glomus mosseae could increase the growths of Suaeda salsa,SOD and CAT activities in leaves and decreased MDA content in leaves.[Conclusion]It preliminarily demonstrated that Arbuscular Mycorrhizal(AM)Fungi could increase salt resistance of Suaeda salsa by increasing the activities of SOD and CAT as well as alleviating membrane injury.展开更多
AdoMet plays numerous roles of being the major methyl-group donor in trans-methylation reactions. To gain insight into the possible functions of the AdoMet protein of Suaeda salsa L. in response to salt stress, S aden...AdoMet plays numerous roles of being the major methyl-group donor in trans-methylation reactions. To gain insight into the possible functions of the AdoMet protein of Suaeda salsa L. in response to salt stress, S adenosylmethionine synthetase gene (SAMS2) was analyzed. We isolated SAMS2 cDNA clone (AF321001) from a lambda -Zap cDNA library constructed from the halophyte S. salsa Pall aerial tissue treated with 400 mmol/L NaCl. SsSAMS2 was found to encode a S-adenolyl-L-methionine synthetase enzyme (AdoMet synthetase). The fragment was 1 531 bp with an open reading frame of 395 amino acids, the calculated molecular weight was about 43 kD. SsSAMS2 showed the highest homology to SAMS2 gene of Catharanthus roseus G. Don., with 93% identity in deduced amino acid sequence. Southern blotting analysis showed that SsSAMS2 might be a two-copy gene in S. salsa genome. Northern blot indicated that the cDNA was up-regulated by salt and other stresses. Enzyme activity assay indicated that the activity of SAMS2 increased under NaCl stress.展开更多
Two different cDNA clones (Sscat1 and Sscat2) encoding catalase, the primary important H2O2-scavenging enzyme, were isolated from a AZap-cDNA library constructed from a 400 mmol/L NaCl-treated library of Suaeda salsa ...Two different cDNA clones (Sscat1 and Sscat2) encoding catalase, the primary important H2O2-scavenging enzyme, were isolated from a AZap-cDNA library constructed from a 400 mmol/L NaCl-treated library of Suaeda salsa ( L.) Pall aerial tissue. Sscat1 (1.7 kb) contains a full open reading frame of 492 amino acids and Sscat2 (1.1 kb) is a partial clone. BLAST analysis indicates that the two clones share 71.9% identity in nucleotide sequence and 75% identity in deduced amino acid sequence within the last 287 amino acid residues of Sscat1. Southern blotting analysis showed that Sscat1 is multicopy in S. salsa genome, while Sscat2 is a single copy gene. Northern blotting analysis showed a rapid increase in the steady-level of both genes in roots after 48 It salt treatment, but only Sscat1 was induced in salinity treated leaves. Time-course analysis carried out in leaves confirmed that Sscat1 was induced by salt stress, in contrast to Sscat2. These implied that the expression of Sscat1 and Sscat2 genes are differentially regulated in S. salsa. The activity of total catalase is dramatically increased in response to salt stress.展开更多
Suaeda salsa L. seedlings grown in Hoagland nutrient solution were treated with different concentrations of NaCl combined with two levels of K + (12 μmol/L and 6 mmol/L) to study the K + nutrition effect on plant g...Suaeda salsa L. seedlings grown in Hoagland nutrient solution were treated with different concentrations of NaCl combined with two levels of K + (12 μmol/L and 6 mmol/L) to study the K + nutrition effect on plant growth and leaf tonoplast V-H +-ATPase and V-H +-PPase activity. Increase of K + supply in the culture solution markedly increased the fresh weight, dry weight and K + content of S. salsa plants. Western blot analysis showed that the leaf V-H +-ATPase of S. salsa was at least composed of A,B,C,D,E and c subunits, and their expression decreased with the increase of NaCl concentration under K + starvation (12 μmol/L K +), but increased under normal K + application (6 mmol/L K +). Leaf V-H +-PPase molecular weight was about 72.6 kD and its expression increased as NaCl concentration increased under both high or low levels of K + concentration in nutrient solution. There was a positive correlation between of V-H +-ATPase or V-H +-PPase activity and the amounts of their expression. Results in this study suggest that K + nutrition plays an important role in the salt tolerance of S. salsa, and K + is involved in the regulation of V-H +-ATPase or V-H +-PPase activity under salt stress.展开更多
基金Under the auspices of Key Program of the National Natural Science Foundation of China(No.U2006215,U1806218)the National Key R&D Program of China(No.2017YFC0505902)。
文摘Spartina alterniflora invasions seriously threaten the structure and functions of coastal wetlands in China.In this study,the Suaeda salsa community in the Yellow River Estuary wetland was monitored using long-term Landsat satellite images acquired from 1997 to 2020 to quantify the impact of changes in hydrological connectivity induced by S.alterniflora on neighboring vegetation com-munities.The results showed that S.alterniflora rapidly expanded in the estuary area at a rate of 4.91 km^(2)/yr from 2010 to 2020.At the same time,the hydrological connectivity of the area and the distribution of S.salsa changed significantly.Small tidal creeks dominated the S.alterniflora landscape.The number of tidal creeks increased significantly,but their average length decreased and they tended to develop in a horizontal tree-like pattern.Affected by the changes in hydrological connectivity due to the S.alterniflora invasion,the area of S.salsa decreased by 41.1%,and the degree of landscape fragmentation increased from 1997 to 2020.Variations in the Largest Patch Index(LPI)indicated that the S.alterniflora landscape had become the dominant landscape type in the Yellow River Estuary.The res-ults of standard deviation ellipse(SDE)and Pearson’s correlation analyses indicated that a well-developed hydrological connectivity could promote the maintenance of the S.salsa landscape.The degradation of most S.salsa communities is caused by the influence of S.alterniflora on the morphological characteristics of the hydrological connectivity of tidal creek systems.
基金Supported by the National Natural Science Foundation of China(30670177)State Ocean863Project(2007AA091701)~~
文摘[Objective] Under salt stress condition,effects of inoculation of arbuscular mycorrhizal fungi Glomus mosseae on SOD and CAT activity in Suaeda salsa seedlings under salt stress were studied.[Method]There were 2 NaCl levels,namely 0 and 400 mmol/L and each NaCl contained 2 treatments,one is inoculated by Glomus mosseae and the other is control.The growths of Suaeda salsa,SOD and CAT activities as well as MDA content in leaves was determined.[Result]Under salt stress condition,Glomus mosseae could increase the growths of Suaeda salsa,SOD and CAT activities in leaves and decreased MDA content in leaves.[Conclusion]It preliminarily demonstrated that Arbuscular Mycorrhizal(AM)Fungi could increase salt resistance of Suaeda salsa by increasing the activities of SOD and CAT as well as alleviating membrane injury.
文摘AdoMet plays numerous roles of being the major methyl-group donor in trans-methylation reactions. To gain insight into the possible functions of the AdoMet protein of Suaeda salsa L. in response to salt stress, S adenosylmethionine synthetase gene (SAMS2) was analyzed. We isolated SAMS2 cDNA clone (AF321001) from a lambda -Zap cDNA library constructed from the halophyte S. salsa Pall aerial tissue treated with 400 mmol/L NaCl. SsSAMS2 was found to encode a S-adenolyl-L-methionine synthetase enzyme (AdoMet synthetase). The fragment was 1 531 bp with an open reading frame of 395 amino acids, the calculated molecular weight was about 43 kD. SsSAMS2 showed the highest homology to SAMS2 gene of Catharanthus roseus G. Don., with 93% identity in deduced amino acid sequence. Southern blotting analysis showed that SsSAMS2 might be a two-copy gene in S. salsa genome. Northern blot indicated that the cDNA was up-regulated by salt and other stresses. Enzyme activity assay indicated that the activity of SAMS2 increased under NaCl stress.
文摘Two different cDNA clones (Sscat1 and Sscat2) encoding catalase, the primary important H2O2-scavenging enzyme, were isolated from a AZap-cDNA library constructed from a 400 mmol/L NaCl-treated library of Suaeda salsa ( L.) Pall aerial tissue. Sscat1 (1.7 kb) contains a full open reading frame of 492 amino acids and Sscat2 (1.1 kb) is a partial clone. BLAST analysis indicates that the two clones share 71.9% identity in nucleotide sequence and 75% identity in deduced amino acid sequence within the last 287 amino acid residues of Sscat1. Southern blotting analysis showed that Sscat1 is multicopy in S. salsa genome, while Sscat2 is a single copy gene. Northern blotting analysis showed a rapid increase in the steady-level of both genes in roots after 48 It salt treatment, but only Sscat1 was induced in salinity treated leaves. Time-course analysis carried out in leaves confirmed that Sscat1 was induced by salt stress, in contrast to Sscat2. These implied that the expression of Sscat1 and Sscat2 genes are differentially regulated in S. salsa. The activity of total catalase is dramatically increased in response to salt stress.
文摘Suaeda salsa L. seedlings grown in Hoagland nutrient solution were treated with different concentrations of NaCl combined with two levels of K + (12 μmol/L and 6 mmol/L) to study the K + nutrition effect on plant growth and leaf tonoplast V-H +-ATPase and V-H +-PPase activity. Increase of K + supply in the culture solution markedly increased the fresh weight, dry weight and K + content of S. salsa plants. Western blot analysis showed that the leaf V-H +-ATPase of S. salsa was at least composed of A,B,C,D,E and c subunits, and their expression decreased with the increase of NaCl concentration under K + starvation (12 μmol/L K +), but increased under normal K + application (6 mmol/L K +). Leaf V-H +-PPase molecular weight was about 72.6 kD and its expression increased as NaCl concentration increased under both high or low levels of K + concentration in nutrient solution. There was a positive correlation between of V-H +-ATPase or V-H +-PPase activity and the amounts of their expression. Results in this study suggest that K + nutrition plays an important role in the salt tolerance of S. salsa, and K + is involved in the regulation of V-H +-ATPase or V-H +-PPase activity under salt stress.
