摘要
蛋氨酸是一种含硫的必需氨基酸,在人类和动物营养中占有重要地位,但很多粮食作物(如豆类)的蛋氨酸含量偏低,通过常规育种手段提高作物蛋氨酸含量的潜力有限。近年来,利用基因工程手段已成功地在许多植物中提高了蛋氨酸的含量。本文综述了通过基因工程手段提高植物蛋氨酸含量的两种途径:提高富含蛋氨酸的储藏蛋白含量和提高游离蛋氨酸的含量。文中重点介绍了蛋氨酸合成过程中的关键酶——胱硫醚γ-合成酶(CGS)的功能、胱硫醚γ-合成酶N端在维持CGS mRNA稳定性方面的作用和对其进行调控的分子机制,指出了目前通过分子育种手段提高蛋氨酸含量方面存在的问题,认为要提高豆类作物的含硫氨基酸含量,应将CGS基因和富含蛋氨酸的储藏蛋白基因同时进行转化。
As a sulfur-containing essential amino acid, methionine is of importance for haman and animal nutrition. In many crops, methionine content is too low to meet the nutritional demand. Conventional breeding was found to be inefficient in modifying the methionine level in plants. However, the genetic engineering methods were proved to be powerful in methionine enhancement in plants. One way is to increase the proportion of methionine-rich protein, and another one is to increase the content of free methionine. In this review, the function of cystathionine γ-synthase （CGS） that is a key enzyme in methionine biosynthesis, the effect of the N-terminal region of CGS on its mR.NA stability, and the ways to manipulate CGS were elucidated. The problems in molecular breeding for methionine enrichment at present were discussed as well in this review. It was proposed that co-expression CGS gene with gene （s） encoding methionine-rich protein might be the effective way for the breeding ofhigh-methionine crops.
出处
《分子植物育种》
CAS
CSCD
2007年第6期849-854,共6页
Molecular Plant Breeding
基金
本研究得到北京市自然科学基金(No.5042019)
973项目(2002CB111301-3)资助
