Heat shock transcriptional factor genes (VfHSFs) of Vitis flexuosa respond differentially to high temperature in grapevines

Abstract

Transcription of defense genes in grapevines function by combining the transcription factors to overcome stresses caused by unfavorable environmental conditions. Heat shock transcriptional factors (HSFs) have the most important role in transcription of genes that respond to high temperatures. The present study identifies the structure and motif location of 19 grape HSF genes in Vitis flexuosa, and investigates their expression patterns in grapevines exposed to high temperatures. Examination of the V. flexuosa transcript database identified 19 VfHSFs, which include VHSFA, VHSFB, and VHSFC. Analysis of the amino acid sequences of VHSF genes revealed 10 motifs. Vines of ‘Campbell Early’, ‘Kyoho’ grapes, and V. flexuosa were exposed to 25 °C, 30 °C, 35 °C, 40 °C and 45 °C in incubation chambers, for varying time points (0, 3, 6, 12 and 24 h). Homologous genes (VfHSFs) of V. flexuosa were predicted by searching the HSF genes in the V. flexuosa transcripts database. Prediction of the protein structure demonstrated that all 19 VfHSF genes of V. flexuosa had an HSF domain. In order to validate the difference in gene expression among cultivars, the relative expression levels were measured using real-time PCR. We found 10 HSF genes (HSF2, HSF3, HSF4, HSF5, HSF7, HSF10, HSF14, HSF16, HSF17, and HSF18) showed differential expression patterns in response to high temperature in ‘Campbell Early’, ‘Kyoho’, and V. flexuosa grapevines. We consider that these results can be useful information to select genetic resources for the future development of heat tolerant grapes, and to study the reaction of grapevines to high temperatures.