桑树病程相关蛋白基因MuPR1-2的克隆及功能分析

Cloning and Functional Analysis of Mulberry Pathogenesis Related Protein Gene MuPR1-2

病程相关蛋白(pathogenesis-related proteins,PRs)是植物体内受病原物或其他环境因子胁迫而诱导表达的一类蛋白质,在植物抗病反应过程中起着非常重要的作用。在桑树叶片中扩增得到MuPR1-2基因(Gen Bank登录号:KC453994),该基因编码区全长609 bp,编码蛋白质含有202个氨基酸,具有一个典型的信号肽和PR蛋白结构域以及PR1蛋白所共有的α-β-α夹心结构。将Mu PR1-2与绿色荧光蛋白基因gfp融合转入拟南芥,通过对转基因拟南芥根尖的显微结构观察,证明MuPR1-2蛋白定位于细胞壁或分泌到细胞间隙。转入MuPR1-2基因的拟南芥对丁香假单胞菌番茄致病变种(Pst DC3000)和灰霉菌具有较强的抵抗能力,表明Mu PR1-2在植物防御功能中具有重要作用。

Pathogenesis-related proteins （PRs） are a group of proteins in plants induced by pathogens and different en- vironmental stresses. They play an important role in plant defense against pathogens. A pathogenesis-related protein gene was cloned from mulberry leaf and named MuPR1-2 （GenBank accession number KC453994）. The full length of its coding region is 609 bp and encodes a protein of 202 amino acids. MuPR1-2 protein possesses one typical signal pep- tide, conserved domains of PR1 proteins and consensus α-β-α sandwich structure. After being fused with gfp gene, Mu- PR1-2 gene was transformed into Arabidopsis. Microstructure observation of transgenic Arabidopsis thaliana plant root tips showed that MuPR1-2 protein was distributed in cell wall or secreted into intercellular space. Transgenic Arabidopsis thaliana plants transformed with MuPR1-2 gene showed strong resistance to Pseudomonas syringae pv. tomato DC3000 （ Pst DC3000） and Botrytis cinerea, indicating that MuPR1-2 gene plays an important role in plant defense.