Evolution of Acyl-CoA-binding protein gene family in plants provides insights into potential functions of grapevine (Vitis vinifera L.)
BACKGROUND: Grapevine was one of the most important perennial fruit crops worldwide. Acyl-CoA-binding proteins (ACBPs) in eudicots and monocots show conservation in an acyl-CoA-binding domain (ACB domain) which binds acyl-CoA esters. OBJECTIVE: The information and data provided in the present study contributes to understand the evolutionary processes and potential functions of this gene family in grapevine growth and development, and responses to abiotic stress. METHODS: Using the complete grapevine genome sequences, we investigated the number grapevine ACBP genes, the exon-intron structure, phylogenetic relationships and synteny with the Arabidopsis ACBP gene family. Furthermore, the expression profiles of VvACBP genes based on public microarray data in different tissues, and the expression patterns responding to different exogenous hormones as well as abiotic and biotic stresses were presented. The qRT-PCR was used to verify the microarray data under drought stress treatments. Finally, the leaf relative water content (RWC), leaf chlorophyll content, and enzymatic activities were measured to further examine the tolerance to drought stress in grapevine. RESULTS: The six grapevine ACBPs were identified. Their distribution into various groups differed from Arabidopsis and rice. Synteny analysis demonstrated that several VvACBP genes were found in corresponding syntenic blocks of Arabidopsis, suggesting that these genes arose before the divergence of the respective lineages. Sequence alignment and structural annotation provided an overview of variations that might contribute to functional divergence from Arabidopsis ACBPs. Expressional analyses suggested that both conserved and variant biological functions exist in ACBPs across different species. The expression pattern of these genes were similar in the microarray and qRT-PCR analyses. Gene structure organization and expression characteristics of VvACBPs resembled those of their Arabidopsis orthologous, although species-specific differences also exist. Differential regulation of genes suggested functional diversification among isoforms. The biochemical and physiological data showed the tolerance to drought stress of grapevine. CONCLUSIONS: These findings provided insight into evolution of ACBP gene family in plants and a solid foundation for a deeper understanding of the complex molecular responses of grapevine to stress.