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
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
cDNA libraries were constructed from the leaves of a rice (Oryza sativa L.) salt tolerancevariety Tesan抋i 2 growing in solutions with 150 mmol/L NaCl for 3 h or without salt stress. Three salt-responsive cDNA clones,...cDNA libraries were constructed from the leaves of a rice (Oryza sativa L.) salt tolerancevariety Tesan抋i 2 growing in solutions with 150 mmol/L NaCl for 3 h or without salt stress. Three salt-responsive cDNA clones, Ts1, Ts2 and Ts3 were isolated by differential screening. Northern blottinganalysis showed that the transcription levels of Ts1 and Ts2 increased within 3 h salt stress and kept onincreasing within 24 h, while the transcription level of Ts3 reached its peak within 3 h. Sequence analysisindicated that there were no homologies between the three cDNA clones and any known gene. The threecDNA clones were mapped using a doubled haploid (DH) population derived from an indica variety ZYQ8,which was a salt tolerance parent of Tesan抋i 2, with a japonica variety JX17. Ts1, Ts2 and Ts3 werelocated on chromosomes 1, 3 and 7, respectively. It was noted that Ts1, Ts2, and Ts3 were in or near theregions of major or minor salt tolerance quantitative trait loci (QTLs), which were mapped in the same DHpopulation in a parallel study.展开更多
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cDNA libraries were constructed from the leaves of a rice (Oryza sativa L.) salt tolerancevariety Tesan抋i 2 growing in solutions with 150 mmol/L NaCl for 3 h or without salt stress. Three salt-responsive cDNA clones, Ts1, Ts2 and Ts3 were isolated by differential screening. Northern blottinganalysis showed that the transcription levels of Ts1 and Ts2 increased within 3 h salt stress and kept onincreasing within 24 h, while the transcription level of Ts3 reached its peak within 3 h. Sequence analysisindicated that there were no homologies between the three cDNA clones and any known gene. The threecDNA clones were mapped using a doubled haploid (DH) population derived from an indica variety ZYQ8,which was a salt tolerance parent of Tesan抋i 2, with a japonica variety JX17. Ts1, Ts2 and Ts3 werelocated on chromosomes 1, 3 and 7, respectively. It was noted that Ts1, Ts2, and Ts3 were in or near theregions of major or minor salt tolerance quantitative trait loci (QTLs), which were mapped in the same DHpopulation in a parallel study.
