Identification of Ubiquitin Ligase From Grapevine Ring C3H2C3E3 and Characterization of Drought Resistance Function of VyRCHC114

Abstract

Background: RING is one of the largest E3 ubiquitin ligase families and C3H2C3 type is the largest subfamily of RING, playing an important role in plants’ development and growth and their biotic and abiotic stress responses. Results: A total of 143 RING C3H2C3-type genes (RCHCs) were discovered from the grapevine genome and separated into groups (I-XI) according to their phylogenetic analysis, with these genes named according to their positions on chromosomes. Gene replication analysis showed that tandem duplications play a predominant role in the expansion of VyRCHCs family together. Structural analysis showed that most VyRCHCs(67.13%) had no more than 2 introns, while genes clustered together based on phylogenetic trees had similar motifs and evolutionarily conserved structures. Cis-acting element analysis showed the diversity of VyRCHCs regulation. The expression profiles of eight DEGs in RNA-Seq after drought stress were similar to those in qRT-PCR analysis. The in vitro ubiquitin experiment showed that VyRCHC114 had E3 ubiquitin ligase activity, overexpression of VyRCHC114 in Arabidopsis improved drought tolerance, moreover, the transgenic plant survival rate increased by 30%, accompanied by changing of electrolyte leakage, chlorophyll content and the activities of SOD, POD, APX and CAT were changed. AtCOR15a, AtRD29A, AtERD15 and AtP5CS1 were expressed quantitatively, the results showed that they participated in the drought stress response may be regulated by the expression of VyRCHC114.Conclusions: Valuable new information on the evolution of grapevine RCHCs and its relevance for studying the functional characteristics of grapevine VyRCHC114 genes under drought stress emerged from this research.