Abstract: In this study, RNA interference was used to down-regulate the gene of starch branch enzyme 3 (sbe3) in rice endosperm in order to increase the content of amylose. The sbe3 gene fragment was isolated from rice by RT-PCR and constructed into the two multi-cloning site regions of pRNAi-ubi in the sense and antisense orientations respectively. This construct was introduced into the rice variety of zhonghua 11 by Agrobacterium-mediated transformation. PCR and southern blot analysis showed that the sbe3 gene is integrated into rice genome. The semi-quantity RT-PCR confirmed that the expression of sbe3 gene is significantly inhibited in the endosperm of T1 transgenic seeds, while the amylose content in the endosperm of T1 transgenic seeds is slightly increased in comparison with the non-transgenic seeds of Zhonghua 11. The results indicated that the suppression of sbe3 gene expression alone by RNA interference shows no dominant effects on the seed amylose content of transgenic rice.

Key words: Oryza sativa L., starch branch enzyme 3 (sbe3), RNA interference, amylose