OsDPE2 Regulates Rice Panicle Morphogenesis by Modulating the Content of Starch

Starch is a carbon sink for most plants, and its biological role changes with response to the environment and during plant development. Disproportionating Enzyme 2 (DPE2) is a 4-α-glycosyltransferase involved in starch degradation in plants at night. LAX1 plays a vital role in axillary meristem initiation of rice . Here, we report that the mutant phenotype of lax1-6 , LAX1 mutant , could be rescued by Oryza Disproportionating Enzyme 2 ( OsDPE 2). OsDPE2 encodes rice DPE2 located in the cytoplasm. Our results show that OsDPE2 affects vegetative plant development of rice by DPE2 activity. Additionally, OsDPE2 regulates vegetative and reproductive plant development of rice by modulating the content of starch of young panicles. Furthermore, haplotype OsDPE2(AQ) with higher DPE2 activity increase the panicle yield of rice. Summery, this study found that OsDPE2 regulates vegetative and reproductive plant development of rice by modulating the content of starch, and the DPE2 activities of OsDPE2 haplotypes were associated with the panicle yield of rice. This study provides guidance and breeding materials for improving panicle yield traits in rice.