苜蓿PGIP3基因的遗传变异、表达与功能研究

项目名称： 苜蓿PGIP3基因的遗传变异、表达与功能研究

项目编号： No.31201840

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 畜牧学与草地科学、兽医学、水产学

项目作者： 桂枝

作者单位： 天津农学院

项目金额： 24万元

中文摘要： 在我国，褐斑病、霜霉病、白粉病和锈病是四种主要的苜蓿病害，均为致病真菌引起的叶部病害，常导致苜蓿的产量降低和品质变劣，是影响苜蓿生产的主要因素之一。多聚半乳糖醛酸酶抑制蛋白（PGIP）被认为是植物重要的防卫蛋白之一，不仅能抑制病原真菌分泌的内切多聚半乳糖醛酸酶的作用，而且可激活特定的植物防卫反应，因而它能够阻止病原物的侵入、减缓病情的发展，最终抑制相应病害的发生。目前，本课题组已获得了苜蓿4个PGIP基因的部分基因组序列，鉴定了其主要等位基因，初步研究了苜蓿受到非生物因素胁迫后这4个PGIP基因的表达规律，结果发现其中一个基因（PGIP3）在叶片中可被多个因素诱导表达，表明它可能与苜蓿对叶部病害的抗性相关。本研究旨在对PGIP3基因的序列变异、表达调节及抑菌功能进行研究，分析其与苜蓿对上述四种病害抗性间的相关性。这项研究是苜蓿PGIP分子病理学和抗真菌病害基因工程育种研究的基础。

中文关键词： 紫花苜蓿；PGIP基因；荧光标记PCR单链构象多态性；单核苷酸多态性；基因组序列分离

英文摘要： Common leaf spot, downy mildew, powdery mildew, and rust are the primary four of the most serious diseases in china, and all of them are caused by fungi and belong to foliar diseases. These four diseases usually cause substantial yield losses and reduce forage quality, and are one of the main factors which restrict the planting of alfalfa. A polygalacturonase-inhibiting protein (PGIP), which is regarded as a key component of plant defense proteins, are able to not only inhibit the activity of endopolygalacturonases from many fungal pathogens but also elicits defense responses in plant. Therefore, it can prevent intrusion of pathogens and slower developing of diseases, and finally restrain occurring of diseases. At present, we have cloned the partial genomic fragments of four PGIP genes from alfalfa and identified their common alleles. In addition, we have preliminarily analyzed the expression pattern of these four genes under the stresses of abiotic factors and found that one of them, PGIP3, could be induced by the most of the used stress factors in leaves and this indicated the gene was possibly related to resistance of alfalfa to foliar diseases. In this study, we aim to research on the genetic variation, expression pattern and functions of PGIP3, and analyze its association with resistance of alfalfa to the a

英文关键词： Medicago sativa；Gene of polygalacturonase-inhibiting protein；Fluorescence-based PCR single-strand conformation；single nucleotide polymorphism；Separation of genome sequence