摘要
大豆种子不仅富含蛋白质,而且赖氨酸含量较高,利用大豆高赖氨酸基因能够弥补谷类作物种子赖氨酸含量的不足。运用现代分子生物学技术,从高蛋白大豆南农87C-38中克隆11S球蛋白Gy7全基因及cDNA序列。经生物公司测序后,利用vectorNTI软件将所克隆的Gy7全基因及cDNA序列与Genbank(AF319776和AF319777)报道的序列进行比对分析,同源性分别为99%和99.6%。序列比对结果显示,Gy7基因cDNA与Genbank报道的序列之间所有的核苷酸差异都位于第3外显子。由此推测,第1、第2和第4外显子编码的氨基酸对于G7多肽形成特定高级结构可能具有非常重要的作用,它们在进化过程中受到的选择压力可能比第3外显子更强。根据遗传密码表推测,克隆的Gy7与Genbank报道的cDNA序列所编码的多肽,两者存在2个氨基酸组成的差异。大豆球蛋白Gy7优质基因的获得为今后利用转基因技术改良水稻、小麦等谷类作物的营养品质奠定了基础。
Rice and wheat are main crops for human consumption, but the seeds in those crops generally lack lysine. Soybean has an abundant storage of protein and lysine,which could help to make up for the lack of lysine in rice and wheat. 11S Glycinin Gy7 gene and its eDNA of soybean Nannong 87C-38 were cloned,independently,with the help of the molecular biotechnology. After being compared the two sequences with Genbank （AF319776 and AF319777）by vector NTI software,their identities were 99% and 99.6%. Interestingly,most differences of the nucleotide acid between Gy7 eDNA and Genbank AF319777 were located in the third extron. Thus we presume that the amino acid coded by the first,second and fourth extrons are more stable and they play a more important role in forming specific structures of the G7 polypeptide than the third extron. According to the genetic code,we presumed the amino acid coded by Gy7 cDNA. There were two amino acid differences from Genbank AF319777. This superior gene cloned in this research could lay the foundation for improving nutritional quality of the crops such as rice and wheat.
出处
《大豆科学》
CAS
CSCD
北大核心
2007年第6期840-846,852,共8页
Soybean Science
基金
上海市科学技术委员会资助项目(063919141)
