Genome-Wide Identification of the Hsp70 Gene Family in Grape and Their Expression Profile during Abiotic Stress

Abstract

Plants encounter a variety of abiotic stresses such as global climate change. Hsp70, as one of the main families of heat shock proteins (Hsps), has a great role in maintenance of the development and growth, and response to abiotic stress. Grape is a very popular fruit worldwide with a high economic value. However, the Hsp70 gene family has not been thoroughly identified in grape (Vitis vinifera L.). In this study, a total of 33 VvHsp70 genes were identified and divided into four clades in V. vinifera. Phylogenetic analysis, gene structure, conserved motif, and duplication events were performed for VvHsp70 genes. The detailed information showed that the VvHsp70 genes clustered together based on the phylogenetic tree had similar subcellular localization, gene structures, and conserved motifs, although there are exceptions. The expression patterns of VvHsp70, VdHsp70, or VaHsp70 were explored in development and abiotic stress including heat, osmotic, and cold stresses by transcription data or qRT-PCR. The results showed that grape Hsp70 genes had strong response for these abiotic stresses, particularly in heat and cold treatments in a different expression pattern. Most of the VdHsp70 genes were upregulated in response to heat treatments while VaHsp70 genes were downregulated in response to cold treatments. Together, our results revealed a new insight for the Hsp70 gene family in grape and will afford fundamental knowledge for further functional analysis and breeding of stress-tolerant grapevines.