【摘要】 ROP(Rho of plant)作为植物中唯一具有信号传递功能的小GTP结合蛋白,在极性生长、发育和环境应答等过程中具有重要作用.本文采用酵母双杂交技术,从水稻幼穗筛选出2种与水稻ROP家族成员OsRac5互作蛋白的基因OsMY1和OsMY2.序列分析显示,OsMY1与OsMY2的核苷酸、氨基酸序列的相似性分别为14%和49%,均含有卷曲螺旋结构域;GST pull down分析显示,OsMY1可以和激活型OsRac5在体外结合;实时定量PCR分析显示,OsMY1和OsMY2在水稻生长发育时期的根、茎、叶中广泛表达,尤其在幼穗中的表达量显著高于其它组织.干旱、低温、高盐等非生物胁迫和植物激素吲哚乙酸(IAA)、脱落酸(ABA)、赤霉素(GA)处理能不同程度地上调OsMY1和OsMY2基因在水稻幼苗中的表达,但油菜素内酯(BR)、水杨酸(SA)、6-苄氨基嘌呤(6-BA)对2种基因的表达没有显著的影响.本文为进一步研究OsMY1和OsMY2基因在水稻生长发育、植物激素和胁迫应答中的功能提供了重要依据,为研究OsMY1、OsMY2和OsRac5蛋白质相互作用的功能联系和作用机制奠定了基础.更多还原

【Abstract】 ROP(Rho of plant) is the sole family of small GTP-binding protein in plants and plays important roles in polar growth,development and responses to enviromental changes.Using rice ROP member OsRac5 as the bait,two putative partner encoding genes of OsMY1 and OsMY2 were isolated by yeast two-hybrid screening from a rice panicle cDNA library.Sequence analysis showed that OsMY1 and OsMY2 both contained a full coiled-coil(CC) domain and shared 14% and 49% similarity respectively in the nucleotide and amino acid sequences.GST pull down assay demonstrated that OsMY1 bound to constitutively activated form of OsRac5(CA-OsRac5) in vitro.Quantitative real-time PCR revealed that OsMY1 and OsMY2 expressed in the roots,stems,and leaves of rice at different developmental stages,especially in panicle.The expressions of OsMY1 and OsMY2 were up-regulated in seedlings by phytohormones and abiotic stresses,such as the treatments of indoleacetic acid(IAA),abscisic acid(ABA),and gibberellin(GA),or drought,cold,salt,but no significant changes were observed with the treatments of brassinosteroids(BR),salicylic acid(SA) and 6-benzyl aminopurine(6-BA).The results can be helpful for the future study of functions of OsMY1,OsMY2 and OsRac5 in the growth,development,and responses to phytohormones and abiotic stresses in rice.更多还原