Zostera marina, a monocotyledonous angiosperm, is one of the most important seagrass species. To inves- tigate the salt-tolerance mechanism and discover salt-tolerant genes in Z. marina, a cDNA library was con- struct...Zostera marina, a monocotyledonous angiosperm, is one of the most important seagrass species. To inves- tigate the salt-tolerance mechanism and discover salt-tolerant genes in Z. marina, a cDNA library was con- structed. Single-pass sequencing of the 5＇ ends of 4 081 clones yielded 4 002 high quality expressed sequence tags （ESTs）, which were assembled into 241 contigs and 1 673 singletons, representing 1 914 unigenes. The average length of the ESTs was 582 bp, with sizes ranging from 100-1 500 bp. Basic Local Alignment Search Tool （BLASTX） analysis revealed that 1 664 unigenes had significant homology to known genes in the Na- tional Center for Biotechnology Information （NCBI） non-redundant （nr） database （E-value≤5-10）. Among them, the two most abundant genes encoded metallothionein （157 ESTs） and chlorophyll a/b-binding pro- tein （38 ESTs）, accounting for 7.1% and 1.7% of the total ESTs, respectively. Using Kyoto Encyclopedia of Genes and Genomes （KEGG）, 1 462 unigenes were assigned to 1 161 pathways （E-value≤5-10）. A total of 938 unigenes were assigned Gene Ontology （GO） terms based on the GO hierarchy analysis, and InterProScan searches recognized 1 003 InterPro families. Three genes for metallothionein in Z. marina that belonged to Class II was identified. Results of this study will improve understanding of the molecular mechanisms of saline tolerance in Z. marina.展开更多
金属硫蛋白(metallothionein,MT)MT3是人体中参与重金属解毒的主要蛋白,前期研究表明啤酒酵母(Saccharomyces c erevisiae)α因子信号肽(MF-α)介导重组蛋白EGFP分泌到植物体外。但是目前还没有研究报道转基因植物中过量表达分泌型MT3...金属硫蛋白(metallothionein,MT)MT3是人体中参与重金属解毒的主要蛋白,前期研究表明啤酒酵母(Saccharomyces c erevisiae)α因子信号肽(MF-α)介导重组蛋白EGFP分泌到植物体外。但是目前还没有研究报道转基因植物中过量表达分泌型MT3对植物重金属镉(Cd)的富集能力是否有影响。本研究通过人工方法合成MF-α信号肽、增强型绿色荧光蛋白(enhanced green fluorescent protein,EGFP)和MT3的融合基因MF-α-EGFP-MT3,构建该融合基因的植物表达载体pK-35S-MF-α-EGFP-MT3,转化野生型(WT)烟草和天竺葵获得转基因植物。通过电化学方法检测转基因植物MT3转录水平、转基因植物根系分泌液中EGFP-MT3蛋白的水平。用Cd溶液处理转基因植物,通过表型观察和电化学方法检测根、茎和叶中Cd的含量。结果表明,转基因烟草和天竺葵中都有MT3基因的转录;且根系分泌EGFP-MT3蛋白的量大约为0.45~0.68 mg·g-1(以鲜质量计)。100μmol·L-1的Cd溶液处理转基因烟草植株,表型变化分析发现转基因植株受损情况低于WT,近根部叶片叶绿素含量显著高于WT,说明EGFP-MT3的分泌可降低Cd的毒害作用。转基因烟草植株根、茎和叶片对Cd的富集量比WT高约40%。用50μmol·L-1的Cd溶液处理转基因天竺葵植株,结果表明转基因植株根对Cd的富集量比WT高约30%,茎对Cd的富集量比WT高约4倍。以上结果证明过量表达EGFP-MT3可以提高转基因烟草和天竺葵对Cd的富集能力,可能是EGFP-MT3分泌根系表面增加转基因植物根系对Cd的吸附作用,同时在转基因植物组织细胞内积累的EGFP-MT3也可增加植物组织对Cd的富集作用。展开更多
基金The Key Science and Technology Program of Shandong Province under contract No. 2012GHY11527Natural Science Foundation of Shandong Province under contract No. Q2007E02+1 种基金Specialized Research Fund for the Doctoral Program of Higher Education (New Teachers) under contract No. 20070423027the Public Science and Technology Research Funds Projects of Ocean, State Oceanic Administration of the People’s Republic of China under contract No. 201105021-8
文摘Zostera marina, a monocotyledonous angiosperm, is one of the most important seagrass species. To inves- tigate the salt-tolerance mechanism and discover salt-tolerant genes in Z. marina, a cDNA library was con- structed. Single-pass sequencing of the 5＇ ends of 4 081 clones yielded 4 002 high quality expressed sequence tags （ESTs）, which were assembled into 241 contigs and 1 673 singletons, representing 1 914 unigenes. The average length of the ESTs was 582 bp, with sizes ranging from 100-1 500 bp. Basic Local Alignment Search Tool （BLASTX） analysis revealed that 1 664 unigenes had significant homology to known genes in the Na- tional Center for Biotechnology Information （NCBI） non-redundant （nr） database （E-value≤5-10）. Among them, the two most abundant genes encoded metallothionein （157 ESTs） and chlorophyll a/b-binding pro- tein （38 ESTs）, accounting for 7.1% and 1.7% of the total ESTs, respectively. Using Kyoto Encyclopedia of Genes and Genomes （KEGG）, 1 462 unigenes were assigned to 1 161 pathways （E-value≤5-10）. A total of 938 unigenes were assigned Gene Ontology （GO） terms based on the GO hierarchy analysis, and InterProScan searches recognized 1 003 InterPro families. Three genes for metallothionein in Z. marina that belonged to Class II was identified. Results of this study will improve understanding of the molecular mechanisms of saline tolerance in Z. marina.
文摘金属硫蛋白(metallothionein,MT)MT3是人体中参与重金属解毒的主要蛋白,前期研究表明啤酒酵母(Saccharomyces c erevisiae)α因子信号肽(MF-α)介导重组蛋白EGFP分泌到植物体外。但是目前还没有研究报道转基因植物中过量表达分泌型MT3对植物重金属镉(Cd)的富集能力是否有影响。本研究通过人工方法合成MF-α信号肽、增强型绿色荧光蛋白(enhanced green fluorescent protein,EGFP)和MT3的融合基因MF-α-EGFP-MT3,构建该融合基因的植物表达载体pK-35S-MF-α-EGFP-MT3,转化野生型(WT)烟草和天竺葵获得转基因植物。通过电化学方法检测转基因植物MT3转录水平、转基因植物根系分泌液中EGFP-MT3蛋白的水平。用Cd溶液处理转基因植物,通过表型观察和电化学方法检测根、茎和叶中Cd的含量。结果表明,转基因烟草和天竺葵中都有MT3基因的转录;且根系分泌EGFP-MT3蛋白的量大约为0.45~0.68 mg·g-1(以鲜质量计)。100μmol·L-1的Cd溶液处理转基因烟草植株,表型变化分析发现转基因植株受损情况低于WT,近根部叶片叶绿素含量显著高于WT,说明EGFP-MT3的分泌可降低Cd的毒害作用。转基因烟草植株根、茎和叶片对Cd的富集量比WT高约40%。用50μmol·L-1的Cd溶液处理转基因天竺葵植株,结果表明转基因植株根对Cd的富集量比WT高约30%,茎对Cd的富集量比WT高约4倍。以上结果证明过量表达EGFP-MT3可以提高转基因烟草和天竺葵对Cd的富集能力,可能是EGFP-MT3分泌根系表面增加转基因植物根系对Cd的吸附作用,同时在转基因植物组织细胞内积累的EGFP-MT3也可增加植物组织对Cd的富集作用。
