【作者】 侯俊杰； 唐燕； 郭健； 李斌； 陈忠正；

【Author】 Junjie Hou Yan Tang Jian Guo Bin Li Zhongzheng Chen~* (College of Food Science,South China Agricultural University,Guangzhou 510642)

【机构】 华南农业大学食品学院；

【摘要】 淀粉是大米的主要成分,淀粉的组成物支链淀粉和直链淀粉在大米中的含量比例决定着大米的食用品质。本研究根据RNA i技术,以调控水稻籽粒支链淀粉合成的sss1,sbe1,sbe3和sbe4四个淀粉酶基因为靶目标,利用RT-PCR方法克隆出上述四个酶基因,通过基因重组技术,将四个酶基因特异片段顺序连接成大片段并经两步组装法将大片段分别正向、反向组装入pRNAi-ubi,成功构建含四个淀粉酶基因的RNAi转化载体pRNAi-ubi/（sss1+sbe1+sbe3+sbe4）,并借助农杆菌介导转基因技术,将构建的转化载体pRNAi-ubi/（sss1+sbe1+sbe3+sbe4）成功转化粳稻中花11获得一批转基因植株。半定量RT-PCR分析表明转基因水稻T₀代籽粒中sss1,sbe1,sbe3和sbe4基因表达均被抑制,但淀粉含量分析表明转基因水稻籽粒中直链淀粉含量并未出现规律性的提高现象,表明水稻籽粒中淀粉合成代谢的复杂性。更多还原

【Abstract】 Rice is rich in starch,whic h is made up of amylose and amylopectin,the ratio of the two determines the characteristics of the rice.The four genes including sssl,sbel,sbe3 and sbe4 which regulate the synthesis of amylopectin of rice were cloned through RT-PCR,and then certain fragments of the four genes were connected in order into one segment.The segment was assembled into pRNAi-ubi in positive and reverse ways,and the RNAi transformation vector pRNAi-ubi /（sssl + Sbel + sbe3 + sbe4）was constructed successfully and transformed into zhonghua 11 by agrobacterium-mediated transformation,and a group of transgenic plants were acquired.Semi-quantitative RT-PCR analysis showed that the expression of T₀ generation of transgenic rice sssl,sbel,sbe3 and sbe4 gene were inhibited,but the starch content analysis showed that the content of amylose in transgenic rice did not show consistent improvement,which showed that the rice might have some other factors affecting the starch metabolism process.更多还原