水稻多逆境响应基因OsGAD3的表达与克隆

Expression and Cloning of Multi-stress Responsive Gene OsGAD3 in Rice

逆境胁迫严重影响植物的生长发育,对农业生产造成相当大的影响。为了了解植物逆境反应机理和发现新的水稻耐逆基因,采用Affymetrix水稻表达芯片分析了籼稻培矮64S在多种逆境胁迫下的表达水平,筛选出一个受多种逆境诱导、在各生长发育时期与组织器官均有响应的基因OsGAD3(Oryza sativa L.,Glutamate decarboxylase 3,GenBank登录号为:AY187941.1)。PCR扩增得到了该基因的cDNA,其包含的ORF长1476 bp,编码一个含有492个氨基酸残基的蛋白,分子量约为56 kD,等电点约为5.64。OsGAD3基因编码的蛋白质有多个保守结构域,经序列比对发现,其与水稻谷氨酸脱羧酶3相似性约为99.7%。启动子区域分析,发现多种与逆境反应相关的顺式作用元件,因此推测此基因可能参与水稻的耐逆反应过程。

Abiotic stresses adversely affect plant growth and cause serious effects on crop production.In order to understand the mechanism underlying stress responses and discover new stress-tolerance genes in rice,expression profiles of indica cultivar Pei＇ai 64S plants were analyzed under stress condtions using the GeneChip Rice Genome Array（Affymetrix） and a stress responsive gene OsGAD3（Oryza sativa,glutamate decarboxylase 3,GenBank accession No： AY187941.1） was identified.The cDNA containing the complete ORF of the gene through amplification was cloned by PCR.The cDNA contains an ORF of 1476 bp and encodes a protein of 492 amino acid residues with M.W.≈ 56kD and pI ≈ 5.64.The protein encoded by the gene had several conserved domains.Comparison with protein sequences in BlastP revealed that OsGAD3 shares 99.7% similarity with glutamate decarboxylase 3 of Nipponbare.Analysis of the putative promoter region of OsGAD3 fonud several cis-elements related to stress responses.Based on the above analyses and results obtained,we propose that OsGAD3 may function as a stress tolerant gene in rice.