A Gene Related to Yeast HOS2 Histone Deacetylase Affects Extracellular Depolymerase Expression and Virulence in a Plant Pathogenic Fungus

Abstract

A gene, HDC1 , related to the Saccharomyces cerevisiae histone deacetylase (HDAC) gene HOS2 , was isolated from the filamentous fungus Cochliobolus carbonum , a pathogen of maize that makes the HDAC inhibitor HC-toxin. Engineered mutants of HDC1 had smaller and less septate conidia and exhibited an ‫ف‬ 50% reduction in total HDAC activity. Mutants were strongly reduced in virulence as a result of reduced penetration efficiency. Growth of hdc1 mutants in vitro was normal on glucose, slightly decreased on sucrose, and reduced by 30 to 73% on other simple and complex carbohydrates. Extracellular depolymerase activities and expression of the corresponding genes were downregulated in hdc1 mutant strains. Except for altered conidial morphology, the phenotypes of hdc1 mutants were similar to those of C. carbonum strains mutated in ccSNF1 encoding a protein kinase necessary for expression of glucose-repressed genes. These results show that HDC1 has multiple functions in a filamentous fungus and is required for full virulence of C. carbonum on maize.

The histone deacetylase Hda1 from Ustilago maydis is essential for teliospore development

“…For Cochliobolus carbonum , a plant pathogenic ascomycete, it has been shown that the HOS2‐related histone deacetylase HDC1 is required for the expression of various glucose‐repressed extracellular enzymes that can depolymerize the plant cell wall. As a consequence, hdc1 mutants are non‐pathogenic (Baidyaroy et al. , 2001).…”

Plant defence suppression is mediated by a fungal sirtuin during rice infection by Magnaporthe oryzae

“…Classical HDACs and their interacting partners have been characterized for roles in plant pathogenicity in a few pathosystems. In the maize pathogen Cochliobolus carbonum , the class II HDAC‐encoding orthologue of yeast HOS2 , HDC1 , was found to be required for virulence (Baidyaroy et al ., ). In Fusarium graminearum , the cause of head blight in wheat and barley, the HOS2 orthologue HDF1 was required for virulence on wheat heads and corn stalks (Li et al ., ).…”

Pleiotropic effects of the histone deacetylase Hos2 linked to H4-K16 deacetylation, H3-K56 acetylation, and H2A-S129 phosphorylation in Beauveria bassiana

“…Hos2 orthologs also exist in filamentous fungi (Brosch, Loidl, & Graessle, ), such as HosA in Aspergillus nidulans (Graessle et al, ) or HDC1 required for extracellular depolymerase expression and virulence in Cochliobolus carbonum (Baidyaroy et al, ). Hos2 has been shown to act as a key component of the Tig1 complex essential for infectious growth and conidiogenesis in Magnaprothe oryzae (Ding et al, ), mediate sexual/asexual development and pathogenesis in Fusarium graminearum (Li et al, ), and act as a downstream component of the cAMP‐PKA pathway and a transcriptional regulator of the mating‐type genes required for dimorphic switch and pathogenesis in Ustilago maydis (Elías‐Villalobos, Fernández‐Álvarez, Moreno‐Sánchez, Helmlinger, & Ibeas, ).…”