关键词: 马铃薯, 高直链淀粉, RNA干扰技术, 淀粉分支酶基因

Abstract: Abstract: 【Objective】To develop high-amylose transgenic potato（Solanum tuberosum L.） plants. 【Method】RT-PCR was employed to clone a 300bp fragment SⅠfrom the CDS of Sbe1 and a 410bp fragment SⅡ from the CDS of Sbe2. Then the two cloned sequences were ligated in tandem to get a fused DNA sequence SⅢ. Plant expression vector pRNAiⅢ with inverted repeat of SⅢ was constructed based on the vectors pHANNIBAL and pART27. Finally，the inverted repeat construct was transformed to elite potato cultivars by Agrobacterium- mediated Transformation. 【Result】Twenty- four regenerated potato plants proved to be transgenic plants after screening with Kan resistance and detection of PCR amplification. Starch of in vitro tuber stained with iodine and visualized under microscope evidenced that twenty-one out of 24 transgenic lines showed a phenotypic change of starch granule structure. The determination of amylose content showed that starch from these 21 lines had an apparent amylose content of 59.31％～87.14％. Result of half-quantity RT-PCR indicated that the accumulation of mRNAs derived from Sbe1 and Sbe2 were not detectable in high-amylose plants. 【Conclusion】 RNAi is an efficient gene silencing method and can be used effectively in the production of high-amylose potato by silencing Sbe1 and Sbe2.