摘要
低分子量麦谷蛋白亚基(LMW-GS)是小麦贮藏蛋白的主要成分,对面团延展性和食品加工品质有重要影响。本研究从西藏小麦地方品种中分离了4个LMW-GS基因(LMW-T1、LMW-T2、LMW-T3和LMW-T4)。LMW-T1、LMW-T2、LMW-T3和LMW-T4都具有LMW-GS基因的典型结构特征,编码区全长分别是930、930、897和915 bp,分别编码308、308、297和303个氨基酸,其推断氨基酸的分子量分别为32938.40、32978.42、31624.88和32122.20 Da。根据推断氨基酸中8个半胱氨酸残基的位置,LMW-T1和LMW-T2属于TypeⅢ类;LMW-T3和LMW-T4属于TypeⅤ类。系统进化树分析表明这4个基因与前人报道的低分子量麦谷蛋白基因相似性很高,其中LMW-T2、LMW-T3和LMW-T4与LMW-m型基因聚为一类。虽然LMW-T1的N-末端的第一个氨基酸是甲硫氨酸,但是LMW-T1与LMW-s型基因聚为一类。上述四个基因的克隆进一步丰富了小麦LMW-GS的基因库资源,有助于进一步了解LMW-GS基因的系统进化、结构与功能,可作为小麦品质改良的候选基因。
The low molecular weight glutenin subunits（LMW-GS） were the major components of wheat storage proteins and had great effects on dough extensibility and food processing quality.Four LMW-GS genes（designated as LMW-T1,LMW-T2,LMW-T3 and LMW-T4） were isolated from Tibet wheat landraces.They were typical LMW-GS genes.The coding regions of LMW-T1,LMW-T2,LMW-T3,and LMW-T4 were 930,930,897 and 915 bp in length,which encoded 308,308,297 and 303 amino acid residues,with the predicted molecular weights of 32 938.40,32 978.42,31 624.88 and 32 122.20 Da,respectively.According to the position of eight cysteine residues in the four deduced amino acid sequences,LMW-T1 and LMW-T2 were classified as TypeⅢ,LMW-T3 and LMW-T4 genes were Type Ⅴ.Phylogenetic analysis indicated that the four genes had high similarity with other LMW-GS genes reported by previous study and LMW-T2,LMW-T3 and LMW-T4 were designated as LMW-m type genes.Although the first amino acid of N-terminal domains of LMW-T1 was methionine,LMW-T1 was designated as LMW-s type genes.The four genes might be new candidate LMW-GS genes with potential value for wheat quality improvement.
出处
《西南农业学报》
CSCD
北大核心
2012年第5期1553-1557,共5页
Southwest China Journal of Agricultural Sciences
基金
中国科学院知识创新工程重要方向(KSCX3-EW-N-02)
