The White Collar Complex is Essential for Sexual Reproduction but Dispensable for Conidiation and Invasive Growth in Fusarium verticillioides

摘要

Fvwcl and Fvwc2, orthologues of the wc-1 and wc-2 genes encoding for proteins of the white collar complex (WCC) in Neurospora crassa were cloned from Fusarium verticillioides and lack-of-function wc mutants were obtained by targeted gene disruption. Photo-conidiation was found to be absent in F. verticillioides, on the contrary, the wild type strain produced less conidia under continuous illumination than in the dark. Inactivation of any of the wc genes led to total female sterility, without affecting male fertility or asexual conidiation. No loss in colonization capability/invasive growth of the wc mutants was observed, when assessed on tomato fruits. Both Fvwcl and Fvwcl showed constitutive expression in the wild type cultures incubated in the dark and exposure to light caused only negligible increases in their transcription. Both Fvwcl and Fvwc2 were down-regulated in a AFvmatl-2-1 gene disruption mutant, lacking a functional mating type (matl-2-1) gene, suggesting that the MAT 1-2-1 product hasa positive regulatory effect on the white collar genes.