Genome-wide identification and characterization of grapevine UFD1 genes during berry development and salt stress response

Grapevine (Vitis vinifera) is widely applicated in food industry, which shows high economical and nutritional values. However, growth of grapevine was usually affected by various environmental stresses, such as salt, drought and disease. Ubiquitin fusion degradation protein 1 (UFD1) is an essential ubiquitin-recognition protein facilitates regulation of stress response through ERAD pathway. Even though, a comprehensive investigation of UFD1 genes in the plant species is still lacking. Here we identified three VvUFD1 proteins from genome of grapevine, which were assigned into different subgroups. All VvUFD1 genes contain highly conserved motifs in structure. Several cis-elements that related to fruit development and stress response were found in the promoter regions of VvUFD1 genes, including bHLH, NCA, MYB, HD-ZIP, GATA and AP2. Expression analysis found VvUFD1 genes showed different expression patterns in different tissues. Most importantly, VvUFD1 genes were found to be involved in salt stress response during growth of grapevine. Transcriptomic analyses were investigated for further understanding the genes' function. Expression of VvUFD1 were increased at late stage of berry ripening. In addition, expression of VvUFD1 were also regulated by elevated light treatment and pathogen Neofusicoccum parvum infection. Co-expression network analysis revealed several major transcription factors that co-expressed with VvUFD1 genes. These results provide a basis for investigating the function of UFD1 genes in plant species and expand understanding of the regulation of berry development and salt stress response in grapevine.