Isolation And Characterization Of Suppressors Of Da3-1 (sud) And Functional Characterization Of The SUD3 Gene

Increasing crop yield and biomass is the important way to realize high yield, and is also one of the important means to solve the problem of food and energy crisis. The size of seeds and organs is an important agronomic trait. Studying of the seed and organ size regulatory mechanism we can solve the current food crisis we are facing, which has important theoretical significance and practical value. Remarkable progress has been made in the field of seed and organ size control in recent years. In Arabidopsis thaliana, the DA3 gene is one of the important factors of seed and organ size control, which encodes a ubiquitin-related protein. The seeds and petals of the da3-1 mutant are larger than those of the wild type, and the da3-1 mutant also shows curly leaves. But the genetic and molecular mechanisms of DA3 in seed and organ size control are totally unknown..To understand the genetic and molecular mechanisms of DA3 in seed and organ size control, we isolate 87 suppressors of da3-1 (sud) using the EMS mutagenesis approach. These suppressors probably have genetic relationships with DA3. We select the sud3 (the suppressor of da3-13) and characterize its phenotypes. The sud3 mutant can almost totally suppress the seed size, ploidy level and leaf shape phenotypes of the da3-1 mutant. We identify the SUD3 gene using resequencing method. Genomic complementation test further shows that the SUD3 gene is cloned. SUD3-GFP is localized in nuclei. The SUD3 may probely be involved in transcriptional regulation. Thus, our findings give important insights to how plants determine their seed and organ size in Arabidopsis.