Bioinformatic analysis of HSF and HSP90 genes in grapevine (Vitis vinifera L.)

Grape production faces significant losses due to various abiotic stresses. Understanding how grapevines respond to these stresses is crucial for developing better cultivation techniques. Heat shock transcription factors (HSFs) and heat shock protein 90 (HSP90) are important proteins in plant stress response. We identified and studied the HSF and HSP90 gene families in grapevines using bioinformatic analysis. We identified 16 VvHSF and 22 VvHSP90 genes in the grape genome, categorizing them into three groups (A, B, C) and four (I, II, III, IV), respectively. The VvHSF proteins have molecular weights ranging from 22.99 to 58.81 kDa and are all unstable, with isoelectric points between pH 4.93 and 9.19. VvHSP90 proteins vary from 41.74 to 167.38 kDa, including stable and unstable members, with isoelectric points from pH 4.74 to 9.31. Chromosomal analysis showed that VvHSF genes are present on 11 chromosomes, while VvHSP90 genes are located on 13 chromosomes. Subcellular localization predictions indicated that all VvHSFs are nuclear, whereas VvHSP90s are mostly cytoplasmic, with some located in the plasma membrane and nucleus. Motif analysis revealed that related proteins share similar motif patterns, suggesting functional similarities. Exon-intron structure analysis indicated that most VvHSF genes have one intron, whereas VvHSP90 genes have between 2 and 20 introns. Three-dimensional modeling demonstrated that both VvHSF and VvHSP90 proteins predominantly feature α-helix folding. Cis-acting regulatory element analysis identified many elements related to hormone and stress responses, highlighting the roles of these genes in various pathways. These findings provide comprehensive insights into the genetics and functions of HSF and HSP90 gene families in grapes, paving the way for future research and improved cultivation strategies.