细胞质特异的PPR蛋白OsPPR2-1在水稻花粉发育中的功能分析

The pentatricopeptide repeat (PPR) protein Family is a eukaryote-speci?c protein family and is particularly large in land plants, with >450 members in Arabidopsis and >430 members in rice. Almost three-quarters of PPR proteins are predicted to be targeted to either mitochondria or chloroplasts and play crucial functions in their RNA metabolism, Such as RNA cleavage, processing, splicing, RNA editing, and translational activation. The PPR proteins are characterized by the presence of tandem arrays of a degenerate 35 amino acid repeat，the PPR motif，repeated in tandem 2-26 times. Bio-chemical structures indicate that PPR protein may combine RNAs and proteins. At present, only a few of PPR proteins have been revealed their biological functions. Recently, we focus on Os02g0110400 , which can express a PPR protein containing 11 PPR motifs, and have found that it may be a cytoplasmic PPR protein and has a significant role in male gametogenesis . Through cytological analysis, We will uncover the cytological characteristics and abortive period of RNAi plants; Through RNA immunoprecipitation we will find the target RNAs of OsPPR2-1; Through the interaction between OsPPR2-1 and target RNAs in vitro, we can confirm the mode of action between them. Our results will uncover the mechanism in which OsPPR2-1 regulates pollen development.

PPR蛋白家族是真核生物所特有的，并且在陆生植物中非常庞大。目前，在拟南芥中已发现多于450个PPR蛋白，水稻中多于430个。大约3/4的PPR蛋白定位在质体与线粒体中，参与质体及线粒体中的RNA代谢，在转录后水平参与基因的表达调控。目前，只有少数PPR蛋白的生物学功能被揭示。最近我们对Os02g0110400的研究发现，它可以编码一个含有11个PPR基序的PPR蛋白，将其命名为OsPPR2-1，定位于细胞质，参与水稻花粉发育。本研究通过细胞学分析，揭示RNAi植株中花粉败育的细胞学特征和败育时期；通过RNA免疫共沉淀分析，确定OsPPR2-1作用的目标RNA；利用OsPPR2-1与RNA互作实验，确定OsPPR2-1与目标RNA作用方式。最终利用这些数据阐明OsPPR2-1参与花粉发育的调控机理。