Plants, Vol. 14, Pages 2725: The Global Transcription Factor FvCon7 Plays a Role in the Morphology, FB1 Toxin Production, and Pathogenesis of Fusarium verticillioides

Plants doi: 10.3390/plants14172725

Authors:
Gaolong Wen
Xiange Lu
Jiayan Liang
Yi Liu
Xudong Zhang
Guodong Lu
Zonghua Wang
Wenying Yu

Fusarium verticillioides, an important global pathogenic fungus, compromises crop quality and yield by infecting maize, sugarcane, and some Solanaceae, endangering food security through contaminated grains and cereals with the fumonisin B1 (FB1) toxin. While Con7 has been reported as a transcription factor involved in the sporulation and pathogenicity of some pathogenic fungi, the function of FvCon7 and its regulatory genes in F.verticillioides remains uncharacterized. Gene deletion mutants of ΔFvcon7 were constructed through homologous recombination, which exhibited defects in vegetative growth, survival, sporophore development, conidiation, conidial germination, and carbon metabolism. Carbon metabolism defects led to a significant accumulation of glycogen granules in hypha and lipid bodies in conidia. Additionally, ΔFvcon7 displayed impaired cell wall structure and integrity, along with an altered expression of genes encoding cell wall-degrading enzymes (such as chitinase), as detected by qRT-PCR. Moreover, Fvcon7 also plays a role in the pathogenicity of maize and sugarcane through different splicing, defective conidia, reduced survival viability, differential expression of secreted proteins, and deficiencies in antioxidant stress capacity. Furthermore, using yeast one-hybrid (Y1H) assays, FvCon7 was found for the first time to directly regulate the expression of FvFUMs by binding to the CCAAT box within the promoters of six key FvFUMs, thereby affecting FB1 production. Overall, FvCon7 functions as a global transcription factor regulating multiple phenotypes. This study provides a theoretical basis for elucidating the mechanism of transcription factor FvCon7 regulating toxin production and pathogenesis in F. verticillioides.

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Gaolong Wen www.mdpi.com