Identification of trihelix transcription factors in grapevine and expression dynamics in response to biotic stress and hormone treatment

Abstract

Transcription Factors (TFs) serve as master regulators of disease resistance in plants. Given the significant roles of trihelix TFs in model plants and their role in multiple disease resistance, current research was aimed at identifying and predicting their tentative function in grapevines. This study discovered 33 complete VvTH genes within the grape genome, categorized into five groups: GT-1 with 5 genes, GT-2 with 8 genes, GTγ with 4 genes, SH4 with 4 genes, and SIP1 with 12 genes. The gene structures and conserved motifs of VvTHs in the same subfamily were highly consistent and contained similar domain patterns. Subcellular localization analysis exhibited that most VvTHs are present in the nucleus region. Chromosomal mapping revealed that VvChr08 and VvChr13 contain the highest number of trihelix family members. In addition, most cis elements found in promoter regions were related to biotic stress response and phytohormone related. ABA-responsive element (ABRE) was identified predominately among members. Dynamic expression profiling of all VvTH genes under various diseases and defense-related phytohormones suggests their involvement in defense regulation. Furthermore, qRT-PCR-based expression analysis revealed the crucial roles of VvTH08, VvTH12, VvTH13, VvTH15, and VvTH22 in anthracnose stress. Our study provides insights into the functions of trihelix transcription factors in grapevine response to multiple biotic stresses and presents new key genes for biotic stress-tolerance breeding.