The Zn2Cys6 transcription factor FocTpc1 is a global regulator of growth, reproduction, pathogenicity, environmental adaptation, and autophagy in Fusarium oxysporum f. sp. cubense

Abstract Fusarium oxysporum f. sp. cubense ( Foc ) is a root-infecting, systemic pathogen that causes Fusarium wilt of banana, posing a significant threat to global banana production. In this study, we identified a Zn 2 Cys 6 transcription factor gene, FocTPC1 (FOIG_02004), which is highly conserved with T PC 1 in Magnaporthe oryzae but lacks a homolog in budding yeast. FocTpc1 localizes to the nucleus and displays transcriptional activity in a yeast two-hybrid system, sharing high conservation with its homologs in filamentous fungi but exhibiting lower protein similarity in yeast fungi. Through gene deletion and phenotypic analysis, we determined that FocTpc1 is essential for vegetative growth, reproduction, and pathogenicity in Foc . Furthermore, we found that FocTpc1 regulates the activities of cell wall-degrading enzymes and the biosynthesis of fusaric acid. Additionally, FocTpc1 is required to modulate the expression of cell wall construction genes and the cell wall stress response. Deletion of FocTPC1 also impaired autophagy, resulting in defects in autophagosome formation and in the proteolysis of GFP-FocAtg8. Under nitrogen-starvation conditions, loss of FocTPC1 disrupted lipid degradation but not glycogen degradation, resulting in significant lipid accumulation in hyphae and microconidia. These findings suggest that FocTpc1 is necessary for autophagy and autophagy-mediated lipid degradation. Using RNA-seq and DAP-seq, we identified 340 putative FocTpc1 targets, many of which are involved in core biological processes, including signal transduction, secondary metabolism, oxidative stress, and metabolic regulation. Our results indicate that FocTpc1 functions as a global regulator in the Foc life cycle.