小花棘豆Embellisia内生真菌的酵母氨酸还原酶基因在苦马豆素代谢中的作用

项目名称： 小花棘豆Embellisia内生真菌的酵母氨酸还原酶基因在苦马豆素代谢中的作用

项目编号： No.31460235

项目类型： 地区科学基金项目

立项/批准年度： 2015

项目学科： 生物科学

项目作者： 卢萍

作者单位： 内蒙古师范大学

项目金额： 52万元

中文摘要： 小花棘豆是内蒙古草原和荒漠区广泛分布的重要疯草物种，该物种许多植株含对牲畜有毒的吲哚里兹啶类生物碱-苦马豆素，苦马豆素可抑制动物细胞内的甘露糖苷酶，牲畜食用后体内相关代谢发生障碍而中毒，造成草原畜牧业重大损失。笔者前期研究表明小花棘豆的苦马豆素毒性由其Embellisia内生真菌引起，有关该内生真菌内苦马豆素的生化代谢途径未知。2012年有研究发现：从美国分布的疯草物种里分离的内生真菌中如果缺乏酵母氨酸还原酶，则苦马豆素及其前体吡啶2-羧酸的含量增加，而酵母氨酸和赖氨酸含量降低。本研究拟应用分子生物学与基因工程技术从小花棘豆内生真菌中分离酵母氨酸还原酶基因序列，然后构建该基因缺失的小花棘豆内生真菌突变株，研究在突变株和野生株中苦马豆素、吡啶羧酸、酵母氨酸和赖氨酸的含量变化及其相互关系，探索酵母氨酸还原酶基因在苦马豆素代谢中的作用，对揭示内生真菌中苦马豆素代谢途径及其分子机制有重要意义。

中文关键词： 分子生物学；基因克隆与表达；基因功能；基因工程；生化代谢

英文摘要： The Oxyrropis glabra is a locoweed species widely distributed in the grassland and desert regions among Inner Mongolia. Many plants of this species contain poisonous swainsonine to livestock. The swainsonine inhibits the activity of mannosidase in animal cells. The relaterd matabolisms in anamals were blocked after feeding the plants, therefore the great loss in animal hasbandry is caused .The previous investigation results of the applicant discovered that the swansonine toxicity of the O.glabra was caused by the fungal endophyte belonging to Embellisia.However,the biochemical pathway of swainsonine in this fungal endophyte is still unknown.It was reported in 2012 that the contents of swainsonine and its precusor pipecolic acid in fungal endophytes isolated from other locoweed species distributed in USA increased along with lacking of saccharopine reductase,while the contents of saccharopine and lysine decreased.In this research the saccharopine reductase gene from our Embellisia fungal endophytes in Oxytropis glabra will be seperated by molecular biological and gene engineering techniques, and the lacking of saccharopine reductase mutant of the fungal endophyte will be constructed.The changes and relationship in contents of swaisonine, pipecolic acid, saccharopine and lysine will be investigated both in the mutant and the wild strain, thus the the function of saccharopine reductase gene in swainsonine metabolism will be explored. The studies are very significant to reveal the biochemical pathway and the molecular toxic mechanism of swainsonine in the fungal endophyte.

英文关键词： molecular biology;gene clonging and expression;gene function;gene engineering;biochemical metabolism