Functional Analysis Of OsAFC2 In Rice(Oryza Sativa L.)

Rice is not only an important crop, but also a model plant for genomic research. Most of eukaryotic genes consist of introns and exons in alternate arrangement, and their correct expression is depended on the precise mRNA splicing to produce proteins of different functions. In Arabidopsis, AtAFC2 proteins can interact with SR proteins, which have some effects on the alternative splicing body, and then play a role in regulating mRNA splicing. In Rice, few studies on genes involved in the regulation of mRNA splicing are reported. In this study, an OsAFC2 gene was cloned and preliminarily studied.1) Through screening rice RNAi library, Rice plants with OsAFC2 gene silencing was gained; Bioinformatic analysis showed that OsAFC2 owned higher homolog to AtAFC2, and they shared 70.05% homologue in amino acid sequence; 2) Subcellular localization experiment showed that OsAFC2 was localized in the nucleus, suggesting that it functions in the nucleus; 3) OsAFC2 were all detected in the various tissues of rice by Real-time quantitative PCR, and moreover, the highest and lowest expression were discovered in leaf blade and stem respectively; 4) OsAFC2 silencing and overexpression vectors were constructed and transformed in Oryza sativa L. japonica. cv. Nipponbare. Chain-specific transcriptomic analysis showed that compared with wild type, the novel alternative splicing cases increased by 50.01% in OsAFC2 silencing lines and to some extent in OsAFC2 overexpression lines,respectively;which implying that the normal expression level of OsAFC2 can regulate SR proteins and cofactors involved in mRNA alternative splicing. As in Arabidopsis, OsAFC2 silencing or overexpression can disturb the phosphorylation level of SR proteins, and affect the interaction between factors associated with mRNA alternative splicing.Therefore, a few specific alternative splicing can not be precisely finished while some novel alternative splicing cases were given birth to.