中国大豆种质11S球蛋白A5A4B3和A3B4亚基缺失的分子机制  

Molecular Mechanism of A_5A_4B_3-null and A_3B_4-null of Chinese Soybean Germplasm

作　　者：刘众悦[1] 王红玲[1,2] 刘春[1,3] 麻浩[1] 

机构地区：[1]南京农业大学作物遗传与种质创新国家重点实验室,南京农业大学大豆所,江苏南京210095 [2]江苏省林业科学院遗传育种研究所,江苏南京211153 [3]衡阳师范学院生命科学系,湖南衡阳421008

出　　处：《大豆科学》2009年第3期363-369,共7页Soybean Science

基　　金：引进国际先进农业计划(948计划)资助项目(2001-207);高等学校学科创新引智计划资助项目

摘　　要：我国大豆种质资源中存在着丰富的主要贮藏蛋白亚基变异类型,它们是大豆品质改良和育种重要的种质基础,因而研究其变异发生的机制有着积极的指导作用。以7个A5A4B3亚基缺失体、2个A3B4亚基缺失体和正常品种为材料,在采用SDS-PAGE验证亚基缺失表现稳定的前提下,克隆得到缺失亚基所对应的基因序列和cDNA序列,然后通过与NCBI上已公布的正常序列进行比较,发现7个材料编码A5A4B3亚基的DNA序列和cDNA序列的起始密码子都由ATG突变成了ATA,形成一个严重错误的翻译阅读框,引起缺失;2个材料编码A3B4亚基的DNA序列并无明显差异,但cDNA序列的终止密码子都由TAA突变成了CAA,可能会导致翻译出来的亚基前体额外多出17个氨基酸的尾巴,引起缺失。There is great genetic diversity in the relative content of seed storage protein subunits in Chinese soybean germplasm, which is the foundation of soybean protein quality improvement. Therefore,it will be helpful for soybean high- quality protein breeding to understand the molecular mechanism of the subunit mutations. Based on the validation of their subunit deficiency by sodium dodecyl sulfate- polyacrylamide gel electrophoresis （ SDS- PAGE）, seven landraces without A5 A4 B3 and two without A3 B4 subunit were used as experimental materials and their subunit mutant gene-sequences and cDNA sequences were obtained. Compared with normal sequences on NCBI,the start codon ATG of the genes and cDNAs encoding the A5 A4 B3- subunits of seven mutant landraces was found to mutate to ATA, which produced a fire-new reading frame of translation and resulted in subunit lacking. While the stop codon TAA of cDNAs encoding A3 B4- subunit of two mutant land- races were found to mutate to CAA, which may resulted in an additional tail in pro-glycinin and caused subunit lacking.

关 键 词：大豆 A5A4B3亚基 A3B4亚基 亚基缺失 密码子点突变 

分 类 号：S565.1[农业科学—作物学]