Comprehensive Genome-Wide Analysis and Expression Pattern Profiling of the Gene Family Unravels Their Likely Involvement in the Abiotic Stress Adaptation of Tomato.

HVA22 family proteins with a conserved TB2/DP1/HVA22 domain are ubiquitous in eukaryotes. family genes have been identified in a variety of plant species. However, there has been no comprehensive genome-wide analysis of family genes in tomato ( L.). Here, we identified 15 non-redundant genes with three segmentally duplicated gene pairs on 8 of the 12 tomato chromosomes. The predicted three-dimensional (3D) models and gene ontology (GO) annotations of SlHVA22 proteins pointed to their putative transporter activity and ability to bind to diverse ligands. The co-expression of genes with various genes implicated in multiple metabolic pathways and the localization of SlHVA22-GFP fused proteins to the endoplasmic reticulum suggested that they might have a variety of biological functions, including vesicular transport in stressed cells. Comprehensive expression analysis revealed that genes were differentially expressed in various organs and in response to abiotic stress conditions. The predominant expression of at the ripening stage and that of , , and in fruits at most developmental stages suggested their probable involvement in tomato fruit development and ripening. Moreover, the transcript expression of most tomato genes, particularly , , , , , and , was affected by abscisic acid (ABA) and diverse abiotic stress treatments, indicating the likely involvement of these genes in tomato abiotic stress responses in an ABA-dependent manner. Overall, our findings provide a foundation to better understand the structures and functional roles of genes, many of which might be useful to improve the abiotic stress tolerance and fruit quality of tomato through marker-assisted backcrossing or transgenic approaches.