紫花苜蓿MsPPR1基因的克隆及抗旱功能分析  

Cloning and function analysis of MsPPR1 in alfalfa under drought stress

作　　者：王少鹏 刘佳[1] 洪军[2] 林积圳 张义[2] 史昆 王赞[1] WANG Shao-peng;LIU Jia;HONG Jun;LIN Ji-zhen;ZHANG Yi;SHI Kun;WANG Zan(College of Grassland Science and Technology,China Agricultural University,Beijing 100193,China;National Animal Husbandry Services,Beijing 100125,China)

机构地区：[1]中国农业大学草业科学与技术学院,北京100193 [2]全国畜牧总站,北京100125

出　　处：《草业学报》2023年第7期49-60,共12页Acta Prataculturae Sinica

基　　金：国家自然科学基金(31761143013);中央高校基本科研业务费(2022RC025)资助。

摘　　要：干旱是影响植物生长发育及产量的重要环境因素,PPR(pentatricopeptide repeats)家族蛋白在植物生长发育以及胁迫响应等生理过程中都具有重要作用。本研究在中苜1号紫花苜蓿中克隆到MsPPR1,利用病毒介导的基因沉默技术和烟草异源表达,在中苜1号紫花苜蓿和烟草中验证了MsPPR1在抗旱性中的功能。结果显示,MsPPR1开放阅读框包含3213 bp,编码1070个氨基酸,相对分子量为121.65 kDa,具有多个PPR重复结构域,定位于细胞质,是典型的PPR蛋白家族成员。MsPPR1主要表达在叶中,其次是茎和根,花中最少;其表达量受自然干旱、甘露醇和脱落酸处理的诱导。通过病毒诱导基因沉默技术在紫花苜蓿中降低了MsPPR1的表达,干旱胁迫下,沉默植株更加萎蔫,相对含水量显著降低,相对电解质渗透率显著升高,显著降低了紫花苜蓿的抗旱性。在烟草中异源超表达MsPPR1,显著增强了转基因烟草的抗旱性,干旱胁迫下,丙二醛含量显著降低,脯氨酸含量增加。以上结果均表明MsPPR1是紫花苜蓿抗旱性的正调控因子,本研究为紫花苜蓿抗旱分子育种提供了候选基因。Drought is an important environmental factor affecting plant growth,development and yield.pentatricopeptide repeats(PPR)family proteins play important roles in plant growth,development,stress response and other physiological processes.In this study,an MsPPR1 gene was cloned from alfalfa(Medicago sativa)cv.Zhongmu No.1,and the drought resistance function of MsPPR1 was investigated through decreasing its expression in alfalfa using a virus induced gene silencing method and heterologous overexpression in tobacco(Nicotiana benthamiana).It was found that the open reading frame contains 3213 bp,encoding 1070 amino acids,and the relative molecular weight of the encoded protein is 121.65 kDa.MsPPR1 is a typical member of the PPR protein family,containing multiple PPR repeat domains and locating in the cytoplasm.MsPPR1 was expressed most in leaves,followed by stems and roots,and least in flowers and induced by drought,mannitol and abscisic acid treatments.The expression of MsPPR1 was decreased by the virus induced gene silencing technology in alfalfa,and decrease of MsPPR1 expression significantly reduced the drought resistance of the plants.The MsPPR1-silenced plants were more wilted,the relative water content was significantly reduced,and the relative electrolyte permeability was significantly increased.The heterologous overexpression of MsPPR1 in tobacco enhanced the drought resistance of transgenic tobacco,while the malondialdehyde content significantly decreased and the proline content increased.This study indicates that MsPPR1 is a positive regulatory factor of alfalfa drought resistance and provides a candidate gene for molecular breeding of alfalfa for drought resistance.

关 键 词：紫花苜蓿 抗旱性 MsPPR1 病毒诱导基因沉默技术 

分 类 号：S541.9[农业科学—作物学]