The Sirtuin Family and Are Important for Fumonisin B Biosynthesis and Conidiation in .

In filamentous fungi, the modification of histone acetylation and deacetylation are crucial for the regulation of secondary metabolism and pathogenicity. So far there has been no functional study on histone deacetylases (HDACs) in , a causal agent of destructive diseases of maize. Herein, we identified and characterized the HDACs and in . Results showed that the disruption of and lead to increased and morphologically abnormal conidia, and consequently high expression levels of conidiation-specific genes. Deletion of and also affected autophagy, which may resulted in the defects of conidial and hyphal viability. Fumonisin B production was significantly reduced in the Δ and Δ mutants, the expression of genes ( and ) involved in secondary metabolism was also significantly down regulated. Notably, and may be involved in histone acetylation at H3K9, H3K14, H3K27, and H4K16 residues, which has never been reported in fungi. Interestingly, FvSIRT5 and FvSIR2 interact with ORC1 (origin recognition complex subunit 1) and some alternative splice forms (ASFs) of FUM21 (fumonisin biosynthetic transcription factor). Moreover, mutations of and are dispensible for virulence in . Taken together, these results suggest that and are important for histone H3 and H4 acetylation and further for transcriptional regulation of genes related to conidiation and secondary metabolism in .