Histone deacetylase MrHos3 negatively regulates the production of citrinin and pigments in Monascus ruber

Abstract

Monascus spp. can produce a variety of beneficial metabolites widely used in food and pharmaceutical industries. However, some Monascus species contain the complete gene cluster responsible for citrinin biosynthesis, which raises our concerns about the safety of their fermented products. In this study, the gene Mrhos3, encoding histone deacetylase (HDAC), was deleted to evaluate its effects on the production of mycotoxin (citrinin) and the edible pigments as well as the developmental process of Monascus ruber M7. The results showed that absence of Mrhos3 caused an enhancement of citrinin content by 105.1%, 82.4%, 111.9%, and 95.7% at the 5th, 7th, 9th, and 11th day, respectively. Furthermore, deletion of Mrhos3 increased the relative expression of citrinin biosynthetic pathway genes including pksCT, mrl1, mrl2, mrl4, mrl6, and mrl7. In addition, deletion of Mrhos3 led to an increase in total pigment content and six classic pigment components. Western blot results revealed that deletion of Mrhos3 could significantly elevate the acetylation level of H3K9, H4K12, H3K18, and total protein. This study provides an important insight into the effects of hos3 gene on the secondary metabolites production in filamentous fungi.

UvHOS3‐mediated histone deacetylation is essential for virulence and negatively regulates ustilaginoidin biosynthesis in Ustilaginoidea virens

“…HOS3 in yeast has the specificity to H2AK7, H2BK11, H3K14, H3K23, H4K5 and H4K8 in vitro (Carmen et al., 1999 ; Gunderson et al., 2011 ; Trojer et al., 2003 ). By contrast, MrHOS3 has an obvious specificity to H3K9 and H3K18 in M. ruber (Liu, Zheng, et al., 2023 ). Detection of site‐specific acetylation reveals that UvHOS3 affects the acetylation levels of H3K9, H3K18, H3K27 and H4K8 in U. virens (Figure 5 ).…”

“…In Monascus ruber , the deletion of Mrhos3 significantly elevates the acetylation levels of H3K9, H3K18 and H4K12. MrHOS3 negatively regulates the production of the mycotoxin citrinin and pigments (Liu, Zheng, et al., 2023 ). However, few studies have been reported on the roles of HOS3 in phytopathogenic fungi so far.…”