Abstract:

【Objective】 In order to control the biosynthesis process of maize starch and to develop transgenic maize with high amylase starch content. 【Method】 RT-PCR was employed to clone the maize starch branching enzyme gene sbe2a and high efficient anti-sense expression vector was constructed based on plant expression plasmid pWGLL. Then the vector was introduced into maize inbred line Tie7922 by pollen tube pathway. 【Result】 Four transgenic plants were obtained. PCR amplification and Southern blotting hybridization proved that the sbe2a had integrated into maize genome. RT-PCR and enzyme activity results showed that both mRNA level of sbe2a and activity of starch branching enzyme decreased significantly in the transgenic plants than that in the wild type plants and the maximum decrease level of enzyme activity was 79.4%. However the total starch content had no significant difference between the transgenic plants and the wild type plants, while the content of amylose starch increased by 84.3% compared to the wild type plants. 【Conclusion】 Anti-sense RNA is an efficient gene silencing method and can be used effectively in the production of high-amylose maize by silencing endogenesis gene sbe2a.

Key words: maize')">maize, high-amylose starch, anti-sense RNA, starch branching enzyme gene sbe2a