Effects Of 24nt-siRNA On MiRNA And The Phenotype Of Rice Grain

24nt-siRNA is the most abundant miRNA in plant.In rice grain,the effects of the change after 24nt-siRNA expressing on the experssion of miRNA remain unclear.In this research,the transgenic rice of three key genes(DCL3a,POLⅣ,RDR2)to produce 24nt-siRNA in pathway are endosperm-specific disturbed,testing siRNA and miRNA expression changes by large-scale sequencing of smallRNA detection,predicting target gene function of different miRNA,analyzing the impact of miRNA expression after reducing grain 24 nt-siRNA expression,to lay the foundation for the study of the mechanism of 24nt-siRNA influence miRNA expression.Q-PCR was used to detect the expression of the target gene in rice grain quantitatively after nine days of rice flowering.The results showed that the expression of three target gene DCL3 a,POLⅣ,RDR2 reduced significantly inRNAi.High-throughput sequencing technology was used to sequence sRNA in target gene silencing significant strain.In three Os DCL3 a,Os POLⅣ,OsRDR2 transgenic lines of interference,the expression of 24nt-sRNA decreased.Compared with wild type Nipponbare,significant increase in expression of miRNA in DCL3ai-6 was54.24%(32/59),that in POLⅣi-1154.84%(17/31),that in 12.20%(5 / 41)RDR2i-23-1;190 different target genes in miRNA were identified via psRNATarget database analysis.Agri GO was used for functional annotation,which showed that its target gene is significantly enriched in the process of biological reproduction,developmental process and the reproductive process.It can be concluded that differences miRNA may play an important role in the regulation of rice grain development.Detecting the expression of Os DCL3 a,Os POLⅣ,OsRDR2 and osa-miR156l-5p,osa-miR167e-3p and the osa-miR1861 d which trend to expressed significantly in the transgenic lines.The results showed that changes in Pre-miRNA and miRNA were consistent,which indicated that the decrease of the expression of 24nt-siRNA affecting miRNA expression occured on the transcriptional level,rather than in thepost-transcriptional processing of miRNA.Analysis of rice plant traits and grain traits,the comparing Japan and transgenic rice show no significant change in plant height,tillering,leaf Angle,and results of designed experimental target in endosperm specificity expected are consistent;Change of single kernel weight and size in transgenic rices.Change of single kernel weight and size in transgenic rices are significant increase.