Genome-wide identification of small heat shock protein (HSP20) genes family in grape and expression profile during berry development process

Abstract

Background Studies have shown that HSP20 genes plays an important role in regulating plant growth, development and stress response. However, the grape HSP20 genes family have not been well studied. Results A total of 51 VvHSP20 genes were confirmed from grape genome. And they were divided into eleven subfamilies (CI, CII, CIII, CV, CVI, CVII, MI, MII, ER, CP and PX/Po) based on the phylogenetic tree and subcellular localization. Further structural analysis showed that the same group of VvHSP20 in the phylogenetic tree had the same motif and the structure was relatively conservative in the evolutionary process. In addition, majority of the VvHSP20 genes were located on the proximate or the distal ends of the chromosomes and four groups of VvHSP20 genes can be identified as tandem duplication genes, which inferred that tandem duplication played a predominant role in the expansion of VvHSP20 family together. To determine the functions of VvHSP20s during the development of grape berries, the expression profiles of VvHSP20s genes were analyzed after H2O2 treatment. VvHSP20s genes indeed involved in the grape berry development and the differences in transcription levels of VvHSP20s may be the result of functional differentiation of genes during evolution. Conclusions The results provide valuable information on the evolutionary relationship of the VvHSP20 family and on the functional properties of the VvHSP20 genes for grape berry development.