玉米淀粉分支酶SBEⅠ基因RNAi干扰载体的构建

Construction of RNAi Vector of Starch Branching Enzyme SBEⅠ of Maize

淀粉分支酶(SBE)催化葡萄糖以α-(1,6)糖苷键连接,形成分支结构。SBE有3种同工酶形式:SBEⅠ、SBEⅡa和SBEⅡb,目前的研究主要集中在SBEⅡb上,而对于SBEⅠ在淀粉合成的作用报道极少。为了明确SBEⅠ在玉米淀粉合成中的作用,扩增了玉米SBEⅠ基因的337bp片段,以pMD19-T为中间载体,pCambia3301为目标载体,构建玉米SBEⅠ基因的RNAi载体,命名为pC3301-SBEⅠ。通过限制性内切酶酶切鉴定,表明pC3301-SBEⅠ载体构建正确,可用于农杆菌介导的玉米自交系转化工作。

The strach branching enzyme （SBE） can introduce a-1,6-glucan linkages to a-1,4-glucan, which make the starch brached. There are three isoforms of SBE： SBE Ⅰ, SBE Ⅱ a and SBE IIb. Many studies were focused on SBE Ⅱ b, and few studies on SBEI. In order to clarify the role of SBEI in starch synthesis, the 337 bp fragment of SBE I gene was amplified based on the sequence AF07272, and used the pMD19-T vector as interim vector the RNAi hairpin of SBE I gene was constructed into pCambia3301 vector, and the new vector was named as pC3301-SBE Ⅰ . Through the identification of restriction endonuclease, the pC3301-SBE Ⅰ was proved to be correct. The new vector was used to transfer maize mediated by agrobacterium tumefaciens.