Identification And Functional Analysis Of Interacting Protein Of Branching Regulatory Protein Abr1 In Rice

Tillering is one of important agronomic traits for contributing to plant architecture and grain yield.However,the rice tillers originated from the elongated internode are usually regarded as ineffective tillers because they barely produce panicles.To avoid excessive nutrient consumption of these ineffective tillers,it is of significance to explore the mechanisms inhibiting the outgrowth of tiller buds on the elongated internode for improving rice architecture and thus increasing grain yield.In our previous study,we reported that the characterization of abnormal branching 1(abrl),a high tillering mutant that caused by activating the outgrowth of dormant tiller buds on the elongated internode.In this research,we found that the increased tillering of abrl is not correlated with the strigolactones(SLs)deficiency.ABR1 encodes a protein that is localized in cytoplasm.ABR1 physically interacts with two homologues,K12A/B,respectively.Interestingly,high tillering phenotype resembling abrl is also observed in kl2a k12b double mutants,indicating that the K12A/B regulate the outgrowth of tiller buds in the elongated internode.These findings show that ABR1 specifically inhibit the outgrowth of tiller buds of the elongated internode by interact with K12A/B in rice.