Identification And Function Analysis Of Flowering-related MicroRNAs In Common Wild Rice (Oryza Rufipogon Griff.)

MicroRNAs (miRNAs) are a class of endogenous, non-coding small RNA (sRNA) which range in size from20to24nucleotides and widely exist in eukaryotic organisms. Its functional mechanism is to negatively regulate genes expression mainly by target gene mRNA sequence-specific cleavage or translation repression in post-transcriptional level, and participate in diverse biological processes including development, organ formation, signal transduction and stress response, etc. My laboratory constructed3small RNA libraries of Guangdong Gaozhou common wild rice (flower twice a year), and sequenced them by Solexa Illumina high-throughput sequencing technology, identified and verified miRNAs in different development stages. Combining targets prediction and cleavage verification, initially found some flowering-related miRNAs and early-flowering variation miRNAs, among them9are wild rice-specific flowering-related miRNAs and16are early-flowering variation miRNAs.My own study is based on the former work of my laboratory, combining targets and precursors prediction, we construct9wild rice-specific flowering-related miRNAs and16early-flowering variation miRNAs’over-expression vectors, and transform the16early-flowering variation miRNAs’over-expression vectors into Arabidopsis thaliana by Agrobacterium to obtain the transgenic plants, then observe8kinds of the transgenic plants (35S:miR160f,35S:miR164d,35S:miR167j,35S:miR169a,35S:miR167f,35S:miR167g,35S:miR530,35S:miR169k) phenotypic variation, such as the number of rosette leaf, bloting time et al. At last, we use mfold to predict the miRNAs’precursor structure and combine the target genes of osa-miR160f in Arabidopsis thaliana, then perform qRT-PCR of35S:miR160f transgenic plant to identify the expression level of its predicted target genes for verifying the function of relevant miRNA.This study can combine the bioinformatics prediction and molecular experiments and better identify the function of flowering-related miRNAs and early-flowering variation miRNAs, which lay the foundation for future research into the molecular mechanisms of flowering diversity in the common wild rice.