To determine the potential impacts of exogenous nitrogen(N)enrichment on distribution and transfer of N in Suaeda salsa marsh in the Yellow River Estuary,the variations of N in plant-soil system during the growing sea...To determine the potential impacts of exogenous nitrogen(N)enrichment on distribution and transfer of N in Suaeda salsa marsh in the Yellow River Estuary,the variations of N in plant-soil system during the growing season were investigated by field N addition experiment.The experiment included four treatments:NN(no N input treatment,0gNm^(−2) yr^(−1)),LN(low N input treatment,3.0 gNm^(−2) yr^(−1)),MN(medium N input treatment,6 gNm^(−2) yr^(−1))and HN(high N input treatment,12 gNm^(−2) yr^(−1)).Results showed that N additions generally increased the contents of total nitrogen(TN),ammonia nitrogen(NH_(4)^(+)-N)and nitrate nitrogen(NO_(3)^(−)-N)in different soil layers and the increasing trend was particularly evident in topsoil.Compared with the NN treatment,the average contents of TN in topsoil in the LN,MN and HN treatments during the growing season increased by 10.85%,30.14%and 43.98%,the mean contents of NH_(4)^(+)-N increased by 8.56%,6.96%and 14.34%,and the average contents of NO_(3)^(−)-N increased by 35.73%,45.99%and 46.66%,respectively.Although exogenous N import did not alter the temporal variation patterns of TN contents in organs,the N transfer and accumulation differed among tissues in different treatments.With increasing N import,both the N stocks in soil and plant showed increasing trend and the values in N addition treatments increased by 9.43%–38.22%and 13.40%–62.20%,respectively.It was worth noting that,compared with other treatments,the S.salsa in the MN treatments was very likely to have special response to N enrichment since not only the period of peak growth was prolonged by about 20 days but also the maximum of TN content in leaves was advanced by approximately one month.This paper found that,as N loading reached MN level in future,the growth rhythm of S.salsa and the accumulation and transference of N in its tissues would be altered significantly,which might generate great impact on the stability and health of S.salsa marsh ecosystem.展开更多
Endophytic bacteria are promising bacterial fertilizers to improve plant growth under adverse environment.For ecological remediation of coastal wetlands,it was necessary to investigate the effect and interaction of en...Endophytic bacteria are promising bacterial fertilizers to improve plant growth under adverse environment.For ecological remediation of coastal wetlands,it was necessary to investigate the effect and interaction of endophytes on halophytes under saline-alkali stress.In this study,an endophytic bacterium strain HK1 isolated from halophytes was selected to infect Suaeda glauca under pH(7 and 8)and salinity gradient(150,300 and 450mmolL^(-1)).Strain HK1 was identified as Pantoea ananatis and it had ability to fix nitrogen,dissolve inorganic phosphorus and produce indole-3-aceticacid(IAA).The results showed that strain HK1 could promote the growth of S.glauca seedings when the salinity was less than 300mmolL^(-1),in view of longer shoot length and heavier fresh weight.The infected plants could produce more proline to decrease the permeability of cells,which content increased by 26.2%–61.1%compared to the non-infected group.Moreover,the oxidative stress of infected plants was relieved with the malondialdehyde(MDA)content decreased by 16.8%–32.9%,and the peroxidase(POD)activity and catalase(CAT)activity increased by 100%–500%and 6.2%–71.4%,respectively.Statistical analysis revealed that increasing proline content and enhancing CAT and POD activities were the main pathways to alleviate saline-alkali stress by strain HK1 infection,and the latter might be more important.This study illustrated that endophytic bacteria could promote the growth of halophytes by regulation of osmotic substances and strengthening antioxidant activities.This finding would be helpful for the bioremediation of coastal soil.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
Betaine is a very effective osmoprotectant found in many organisms. In high plants, betaine is synthesized by oxidation of choline in two sequential steps: choline-->betaine aldehyde-->betaine. The first step is...Betaine is a very effective osmoprotectant found in many organisms. In high plants, betaine is synthesized by oxidation of choline in two sequential steps: choline-->betaine aldehyde-->betaine. The first step is catalyzed by choline monooxygenase (CMO). In this study, the full-length CMO cDNA (1 820 bp) was cloned from halophyte Suaeda liaotungensis Kitag by RT-PCR and RACE. It included a 123 bp 5' UTR, a 368 bp 3' UTR and a 1 329 bp open reading frame encoding a 442-amino-acid polypeptide with 77%, 72% and 74% sequence identity compared to CMOs from spinach, sugar beet and Atriplex hortensis, respectively. The CMO open reading frame (ORF) was cloned and the plant expression vector pBI121-CMO was constructed. It was transferred into tobacco ( Nicotiana tabacum L. ev. 89) via Agrobacterium mediation. PCR and Southern blotting analysis showed that the CMO gene was integrated into tobacco genome. Transgenic tobacco plants contained higher amount of betaine than that of control plants and were able to survive on MS medium containing 250 mmol/L NaCl. Relative electronic conductivity demonstrated less membrane damage in transgenic plants as in the wild type.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
The 5＇-flanking proximal region of stress-induced gene encoding choline monooxygenase （CMO） was isolated by Adaptor-PCR and TAIL-PCR from halophyte Suaeda liaotungensis K. A total of 2,204 bp DNA sequence was obtai...The 5＇-flanking proximal region of stress-induced gene encoding choline monooxygenase （CMO） was isolated by Adaptor-PCR and TAIL-PCR from halophyte Suaeda liaotungensis K. A total of 2,204 bp DNA sequence was obtained. The transcription start site, which is located at 128 bp upstream to the start ATG, was predicted by the TSSP-TCM program. The functional elements were analysed by PLACE program. The obtained SICMO gene promoter contains the basic elements： TATA-box, CAAT-box, and stress-induced elements, for example, salt responsive element （GAAAAA）, cold responsive elements （CANNTG）, ABA （Abscisic Acid） responsive elements （NAACAA）, water stress element （CGGTTG）, and WUN responsive elements （GTTAGGTTC）. Isolation and analysis of the promoter of the CMO gene from S. liaotungensis lays a foundation for characterising the stress-induced promoter elements, studying the relationship between the structure and function of the promoter, and investigating the molecular mechanism of CMO gene regulation.展开更多
[Objective] This study was to investigate the Suaeda salsa community characteristics,further getting the soil chemical properties.[Method] The paired-data of field spectra and corresponding soil physical-chemical prop...[Objective] This study was to investigate the Suaeda salsa community characteristics,further getting the soil chemical properties.[Method] The paired-data of field spectra and corresponding soil physical-chemical property of seventeen samples was used to reveal the relationship between soil chemical property and field spectra（visible and near infra-red spectra）of S.salsa.[Result] The second derivative spectrum of S.salsa at 1 121 nm could reflect the changes of soil organic matter and soil total nitrogen,and that at 1 208 nm could commendably indicate changes of soil total phosphorus and at 724 nm could indicate changes of soil pH.The first derivative spectrum of S.salsa at 353 nm can indicate changes of soil available potassium,and that at 950 nm could commendably reflect the changes of soil salt content.[Conclusion] Our results laid basis for monitoring chemical property of soil covered with S.salsa using remote sensing technology.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.41371104,41971128)the Award Program for Min River Scholar in Fujian Province(No.Min[2015]31).
文摘To determine the potential impacts of exogenous nitrogen(N)enrichment on distribution and transfer of N in Suaeda salsa marsh in the Yellow River Estuary,the variations of N in plant-soil system during the growing season were investigated by field N addition experiment.The experiment included four treatments:NN(no N input treatment,0gNm^(−2) yr^(−1)),LN(low N input treatment,3.0 gNm^(−2) yr^(−1)),MN(medium N input treatment,6 gNm^(−2) yr^(−1))and HN(high N input treatment,12 gNm^(−2) yr^(−1)).Results showed that N additions generally increased the contents of total nitrogen(TN),ammonia nitrogen(NH_(4)^(+)-N)and nitrate nitrogen(NO_(3)^(−)-N)in different soil layers and the increasing trend was particularly evident in topsoil.Compared with the NN treatment,the average contents of TN in topsoil in the LN,MN and HN treatments during the growing season increased by 10.85%,30.14%and 43.98%,the mean contents of NH_(4)^(+)-N increased by 8.56%,6.96%and 14.34%,and the average contents of NO_(3)^(−)-N increased by 35.73%,45.99%and 46.66%,respectively.Although exogenous N import did not alter the temporal variation patterns of TN contents in organs,the N transfer and accumulation differed among tissues in different treatments.With increasing N import,both the N stocks in soil and plant showed increasing trend and the values in N addition treatments increased by 9.43%–38.22%and 13.40%–62.20%,respectively.It was worth noting that,compared with other treatments,the S.salsa in the MN treatments was very likely to have special response to N enrichment since not only the period of peak growth was prolonged by about 20 days but also the maximum of TN content in leaves was advanced by approximately one month.This paper found that,as N loading reached MN level in future,the growth rhythm of S.salsa and the accumulation and transference of N in its tissues would be altered significantly,which might generate great impact on the stability and health of S.salsa marsh ecosystem.
基金supported by the Shandong Province’s Natural Science Foundation(No.ZR2019MD033).
文摘Endophytic bacteria are promising bacterial fertilizers to improve plant growth under adverse environment.For ecological remediation of coastal wetlands,it was necessary to investigate the effect and interaction of endophytes on halophytes under saline-alkali stress.In this study,an endophytic bacterium strain HK1 isolated from halophytes was selected to infect Suaeda glauca under pH(7 and 8)and salinity gradient(150,300 and 450mmolL^(-1)).Strain HK1 was identified as Pantoea ananatis and it had ability to fix nitrogen,dissolve inorganic phosphorus and produce indole-3-aceticacid(IAA).The results showed that strain HK1 could promote the growth of S.glauca seedings when the salinity was less than 300mmolL^(-1),in view of longer shoot length and heavier fresh weight.The infected plants could produce more proline to decrease the permeability of cells,which content increased by 26.2%–61.1%compared to the non-infected group.Moreover,the oxidative stress of infected plants was relieved with the malondialdehyde(MDA)content decreased by 16.8%–32.9%,and the peroxidase(POD)activity and catalase(CAT)activity increased by 100%–500%and 6.2%–71.4%,respectively.Statistical analysis revealed that increasing proline content and enhancing CAT and POD activities were the main pathways to alleviate saline-alkali stress by strain HK1 infection,and the latter might be more important.This study illustrated that endophytic bacteria could promote the growth of halophytes by regulation of osmotic substances and strengthening antioxidant activities.This finding would be helpful for the bioremediation of coastal soil.
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Betaine is a very effective osmoprotectant found in many organisms. In high plants, betaine is synthesized by oxidation of choline in two sequential steps: choline-->betaine aldehyde-->betaine. The first step is catalyzed by choline monooxygenase (CMO). In this study, the full-length CMO cDNA (1 820 bp) was cloned from halophyte Suaeda liaotungensis Kitag by RT-PCR and RACE. It included a 123 bp 5' UTR, a 368 bp 3' UTR and a 1 329 bp open reading frame encoding a 442-amino-acid polypeptide with 77%, 72% and 74% sequence identity compared to CMOs from spinach, sugar beet and Atriplex hortensis, respectively. The CMO open reading frame (ORF) was cloned and the plant expression vector pBI121-CMO was constructed. It was transferred into tobacco ( Nicotiana tabacum L. ev. 89) via Agrobacterium mediation. PCR and Southern blotting analysis showed that the CMO gene was integrated into tobacco genome. Transgenic tobacco plants contained higher amount of betaine than that of control plants and were able to survive on MS medium containing 250 mmol/L NaCl. Relative electronic conductivity demonstrated less membrane damage in transgenic plants as in the wild type.
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.
基金This work was supported by the National Natural Sciences Foundation of China (No. 30370806).
文摘The 5＇-flanking proximal region of stress-induced gene encoding choline monooxygenase （CMO） was isolated by Adaptor-PCR and TAIL-PCR from halophyte Suaeda liaotungensis K. A total of 2,204 bp DNA sequence was obtained. The transcription start site, which is located at 128 bp upstream to the start ATG, was predicted by the TSSP-TCM program. The functional elements were analysed by PLACE program. The obtained SICMO gene promoter contains the basic elements： TATA-box, CAAT-box, and stress-induced elements, for example, salt responsive element （GAAAAA）, cold responsive elements （CANNTG）, ABA （Abscisic Acid） responsive elements （NAACAA）, water stress element （CGGTTG）, and WUN responsive elements （GTTAGGTTC）. Isolation and analysis of the promoter of the CMO gene from S. liaotungensis lays a foundation for characterising the stress-induced promoter elements, studying the relationship between the structure and function of the promoter, and investigating the molecular mechanism of CMO gene regulation.
基金Supported by National Natural Science Foundation of China(40771172)Program for the Independent Innovation Team at State Key Laboratory of Resources and Environmental Information System(088RA400SA)Pilot Program of Knowledge Innovation Projectfrom Chinese Academy of Science~~
文摘[Objective] This study was to investigate the Suaeda salsa community characteristics,further getting the soil chemical properties.[Method] The paired-data of field spectra and corresponding soil physical-chemical property of seventeen samples was used to reveal the relationship between soil chemical property and field spectra（visible and near infra-red spectra）of S.salsa.[Result] The second derivative spectrum of S.salsa at 1 121 nm could reflect the changes of soil organic matter and soil total nitrogen,and that at 1 208 nm could commendably indicate changes of soil total phosphorus and at 724 nm could indicate changes of soil pH.The first derivative spectrum of S.salsa at 353 nm can indicate changes of soil available potassium,and that at 950 nm could commendably reflect the changes of soil salt content.[Conclusion] Our results laid basis for monitoring chemical property of soil covered with S.salsa using remote sensing technology.
