菜豆泛肽基因在生物和非生物胁迫下的表达

Gene expression analysis of ubiquitin from bean under biotic and abiotic stress

差别筛选 Hg Cl2 胁迫处理的菜豆 (Phaseolus vulgaris L .)幼苗叶片 c DNA库 ,分离出1个重金属胁迫响应基因 Pv SR5 2克隆 ,其 c DNA长度为 2 81 bp。 c DNA和氨基酸序列同源性分析表明 Pv SR5 2编码一种多聚泛肽。Southern blot结果表明菜豆泛肽可能由少数基因编码。Northern blot分析表明多聚泛肽叶片中表达较少 ;重金属 Hg、Cd和 As等、过量的 Zn和Cu及高温、病毒侵染和水杨酸等环境胁迫均能强烈地刺激其在叶片中的表达。

A heavy metal responsive gene PvSR52 was isolated from a mercuric-chloride-treated bean (Phaseolus vulgaris L.) cDNA library by differential screening using cDNAs derived from treated and untreated plants.The PvSR52 cDNA,which contained only 281 bp,was not a full-length cDNA clone.Homology analysis of cDNA and amino acid sequence showed that PvSR52 cDNA encoded a polyubiquitin.Southern blot analysis showed that ubiquitin genes maybe encoded by a small gene family.Northern blot analysis revealed a low level of transcripts of ubiquitin in unstressed bean leaves,but the gene expressions were strongly stimulated by metals (such as Hg,Cd,As,Zn and Cu),elevated temperature,virus infection and salicylic acid.These suggested that ubiquitin proteolysis system might play important roles in resistance to various environmental stresses.