Functional Analysis Of Tillering Angle Gene TAC8 In Rice

Rice plant type is an important trait to control yield.Tiller looseness has a direct impact on density of rice planting,photosynthesis,sheath blight,ventilation.Breeding new rice varieties with moderate tiller angle can significantly increase rice Yield.The tillering angle of rice,a complex trait controlled by multiple genes and is susceptible to environmental factors.So far there have been relatively few reports on the tillering angle genes of rice.In this study,based on the fine mapping of rice tiller angle QTL TAC8,the function of its candidate genes was verified,and the control of rice tiller angle gene TAC8 was cloned.The main findings were as follows:1.The four candidate genes of the two parents were sequenced and compared,and it was found that the two genes,LOC＿Os08g33530 and LOC＿Os08g33590,had differences in large base fragments.And the base differences of the LOC＿Os08g33530 genes of the two parents were in the protein functional domain of the gene.2.The p YLCRISPR/Cas9 knockout vector was constructed by CRISPR/Cas9 system single-target knockout.A total of 45 positive transgenic plants with a positive clone rate of42.8%and many mutant types was obtained by transgenic experiments.The overexpression vectors p HF-611-Hpt-HA and Phf-613-Hpt-GEP were constructed by TAC8 gene,transgenic plants have not been obtained.There was a significant effect on the trait of rice tillering angle of the TAC8 gene,which had a significant effect on reducing the tillering angle,by haplotype analysis.3.The chimeric mutants and heterozygous mutants of the knock-out T₀generation need to be further selfed,and all four genes have relatively abundant mutant materials.The chimeric mutation rates were:22.2%,47.1%,23.1%,and 40.0%;the heterozygous mutation rates were:66.7%,23.5%,7.69%,and 20.0%,respectively.4.There are few homozygous mutants in the T0 generation transgenic plants.There was significant differences in candidate genes,which in the tillering angle and the number of effective tillers by the phenotype identification of homozygous mutants.Tiller angle and effective tiller number were decreased but the seed rate was increased in the homozygous clone of gene LOC＿Os08g33580.While tiller angle,effective tiller number and the seed rate were increased in the homozygous clone of gene LOC＿Os08g33530.Tiller angle analysis was performed on T₁,and the LOC＿Os08g33580 gene was the target gene for research.