盐胁迫是影响植物生长、发育以至产量的重要因素,野生大豆是优良的非生物胁迫抗性材料,是天然的优质抗性基因库。本研究以耐盐东北野生大豆为试材,利用东北农业大学植物生物工程研究室已获得的基因芯片杂交结果,对植物生物工程研究室构建的野生大豆盐胁迫EST数据库中各EST在胁迫下的表达情况进行了分析,从中选出了1个在高盐、低温、干旱胁迫早期均上调表达的3′-EST,序列分析表明该EST编码质膜结合蛋白(plasmamembrane intrinsic protein,PIP),属于主嵌入蛋白(major intrinsic protein,MIP)家族;通过电子克隆和改进的5′-RACE获得了基因完整的编码区;其翻译产物与含羞草质膜结合蛋白的相似性为90%,将该基因命名为GsPIP。GsPIP基因的翻译产物具有主嵌入蛋白家族特征性的跨膜结构域,无信号肽,与已发现的植物PIP蛋白一致。本研究获得的基因具有自主知识产权,通过进一步的功能分析,可为耐渗透胁迫基因工程研究提供基因资源,并为植物耐渗透胁迫机理研究提供依据。
Salt stress affects plant growth and development and reduces productivity of crops.Glycine soja is an excellent material for isolation of abiotic stress related genes because of its tolerance to several kinds of stresses.An EST database of a salt tolerant variety of G.soja was constructed in previous work,and a gene expression profile was obtained by gene chip assay.Expression of all G.soja ESTs were analyzed,and one 3′-EST induced by cold,high salt and drought stress was chosen.This EST represents a plasma membrane intrinsic protein(PIP) gene,which belongs to the major intrinsic protein(MIP) family.A complete CDS of this gene was obtained with silico cloning and was developed with 5′-RACE.The translation product of this gene has 90% similarity with a PIP protein of Mimosa pudica and was named GsPIP.The translation product had the characteristic domain of MIP but has no signal peptide: This is consistent with PIPs of other plants.We isolated the GsPIP gene on our own and we have all intellectual property rights.It could become a new gene source for genetic engineering of stress tolerance.Further functional analysis would assist research on the mechanisms of osmotic stress tolerance.