The role of transcription factors TGA2, TGA5 and Why1 in sunflower response to infection by Orobanche cumana Wallr

The transcription factors TGA2, TGA5, and Why1 play essential roles in plant responses to biotic and abiotic stress, being involved in hormonal signaling (SA, ABA, JA), detoxification of reactive oxygen species, and activation of PR genes. In the present study, the expression of these factors was analyzed in three sunflower genotypes, exhibiting different levels of resistance to the holoparasite Orobanche cumana, under both infested and non-infested conditions. The results reveal distinct transcriptional profiles among genotypes, with significant upregulation or downregulation of TGA2 and TGA5 in resistant lines, particularly at 12 and 24 hours post-inoculation, and a general decrease in Why1 expression. The study confirms the involvement of these transcription factors in early resistance mechanisms against biotic stress and suggests their potential as molecular markers for selecting resistant genotypes