miR2275在荔枝花性别分化过程中的作用机理研究

雄花量大、雌花量相对不足是影响荔枝丰产的重要原因，调节雌雄花比例以提高产量是荔枝生产中急需解决的一个重要问题。申请人前期研究发现荔枝miR2275及其诱导产生的24-nt phasiRNA可能参与荔枝花性别分化。为求证并进一步深度挖掘和解析miR2275作用机理，本项目拟：（1）对miR2275及其诱导产生的phasiRNA的靶基因进行全方位鉴定，并对它们的功能作用方式进行探索性研究；（2）对miR2275、phasiRNA以及它们的靶基因在荔枝花性别分化过程中的表达调控模式进行更仔细分析；（3）开发倒地铃遗传转化体系，对关键编码或非编码靶基因进行功能验证。上述研究结果既可明确miR2275-phasiRNA这一保守调控通路的功能作用方式，又有助于解析miR2275调控荔枝花性别分化过程的分子机理，为生产开发有效的花性调控技术，实现丰产和稳产提供理论支撑。

In litchi, disproportional composition of flowers, with overabundant male flowers and less female flowers, greatly affect the yield of fruit production. How to balance the ratio of male and female flowers is a big problem for the industry of litchi production. Our previous studies indicated that miR2275 and its ensuing 24-nt phasiRNAs were likely involved in the process of flower sex determination (FSD) in litchi. To further explore the mechanism of miR2275 function, this project aims to: (1) identify thoroughly the target genes of miR2275 and phasiRNAs and explore their potential functional network; (2) profile in high resolution the expression of miR2275, phasiRNAs and target genes in the process of FSD; (3) develop a genetic transformation system of balloon vine (Cardiospermum halicacabum), and use to validate the biological function of miR2275 and candidate target genes in FSD. Results from this project will not only expand our understanding of the function of the miR2275-phasiRNA pathway which is conserved in plants, but also help uncover the molecular mechanism of miR2275 role in FSD in litchi. These knowledges will be greatly helpful for us to develop practical approaches to control the flower sex determination, to eventually achieve stable and high yield of fruit production in litchi.