Molecular Mechanism Of TE2 Regulating Tiller Number In Rice

Rice tillering is one of the important factors that constitute the ideal plant type of rice,and the effective tillering number is one of the key factors for rice yield composition.Our laboratory identified a rice tillering-related gene TE2 in the early stage.The number of tillers in this gene mutant was significantly reduced compared with the wild type.At the same time,we over-expressed this gene in wild-type Nipponbori through transgenic technology and obtained TE2 over-expressing transgenic plants.The tiller number of the over-expressing plants was exactly the opposite of that of the mutant,and the tiller number was significantly increased compared to the wild type.The mutant and over-expressing plants were used as the research material for this experiment.In this experiment,experimental techniques such as observation of tiller buds,GUS staining,subcellular localization,yeast sieve library,yeast two-hybrid interaction analysis,and RNA-seq analysis were used to explore the function of the TE2 gene.The results are as follows:(1)The number of tillers at the tillering stage and the effective tillering at mature stage of the over-expressed plants TE2-OE were significantly higher than those of the wild type control,while the te2 mutant was just the opposite,and the tillering and effective tillering numbers were lower than those of the wild type.(2)For the statistics of other agronomic traits,in the 1000-grain weight,plant height,number of grains per ear,seed setting rate,spike length,sword leaf length,sword leaf width,grain length,grain width,and grain thickness,none of the three were found to be significant.Variety.Yield per plant and 50 plots were counted.It was found that mutants were significantly lower than wild type,and over-expressed plants were significantly higher than wild type.(3)The tissue expression analysis of the TE2 gene revealed that the gene was expressed in different tissues in different periods of rice,and the expression was high in tillering buds,leaves and sheaths.(4)The subcellular localization of TE2 gene is mainly expressed in cytoplasm and cell membrane.(5)Through yeast two-hybrid sieve library and one-to-one verification,a protein interaction between TAD1 and TE2,a key factor for tiller regulation,was found,and qPCR showed that the expression of MOC1,OsH1,and OsTB1 downstream genes regulated by TAD1 significantly changed.(6)Using RNA-seq technology to perform transcriptome sequencing and GO,KEGG analysis on te2 mutants,TE2-OE overexpressing plants and their wild-type controls,It was found that OsCKXs and OsRRs related genes involved in cytokinin signal transduction pathway were significantly different in mutants and overexpressing plants.(7)Over-expression of this gene in different main varieties can increase the tiller number and effective tiller number of plants.In summary,TE2 gene may regulate rice tillering through the MOC1 pathway and affect the expression of its upstream and downstream genes,and may also regulate rice tillering through plant hormone pathways such as cytokinins.These results not only enrich the knowledge of molecular mechanism of rice tillering,but also provide new theoretical support for improving the high-yielding molecular breeding of rice tillering.