The Tig1 Histone Deacetylase Complex Regulates Infectious Growth in the Rice Blast Fungus Magnaporthe oryzae      

Abstract

Magnaporthe oryzae is the most damaging fungal pathogen of rice (Oryza sativa). In this study, we characterized the TIG1 transducin b-like gene required for infectious growth and its interacting genes that are required for plant infection in this model phytopathogenic fungus. Tig1 homologs in yeast and mammalian cells are part of a conserved histone deacetylase (HDAC) transcriptional corepressor complex. The tig1 deletion mutant was nonpathogenic and defective in conidiogenesis. It had an increased sensitivity to oxidative stress and failed to develop invasive hyphae in plant cells. Using affinity purification and coimmunoprecipitation assays, we identified several Tig1-associated proteins, including two HDACs that are homologous to components of the yeast Set3 complex. Functional analyses revealed that TIG1, SET3, SNT1, and HOS2 were core components of the Tig1 complex in M. oryzae. The set3, snt1, and hos2 deletion mutants displayed similar defects as those observed in the tig1 mutant, but deletion of HST1 or HOS4 had no detectable phenotypes. Deletion of any of these core components of the Tig1 complex resulted in a significant reduction in HDAC activities. Our results showed that TIG1, like its putative yeast and mammalian orthologs, is one component of a conserved HDAC complex that is required for infectious growth and conidiogenesis in M. oryzae and highlighted that chromatin modification is an essential regulatory mechanism during plant infection.

Two Histone Deacetylases, FfHda1 and FfHda2, Are Important for Fusarium fujikuroi Secondary Metabolism and Virulence

“…However, strong GFP signals were observed for the constructs with the oliC promoter. Both FfHda1::GFP and FfHda2::GFP predominantly localized to the nucleus, as also previously shown for HDF1 in F. graminearum and its homolog Hos2 in Magnaporthe oryzae (24,72). In addition, a faint GFP signal was also visible in the cytoplasm of vegetative hyphae in both mutants (see Fig.…”

“…Deletion of HDC1 and hos2 (ffhda2 homolog) in Cochliobolus carbonum and Magnaporthe oryzae, respectively, resulted in mutants that were greatly impaired in pathogenicity, while deletion of the ffhda1 and ffhda4 homologs hda1 and hos3 had no or only weak effects on M. oryzae (72,84). Similarly, deletion of HDF1 (ffhda2 homolog) had the greatest impact on virulence in F. graminearum.…”

Fungus-Specific Sirtuin HstD Coordinates Secondary Metabolism and Development through Control of LaeA

“…Recently, histone deacetylases in some filamentous fungi have been investigated for their role in the regulation of histone modification, developmental processes, stress resistance, pathogenesis, metabolism, and other such processes (2,(7)(8)(9)(10). For example, the homolog of yeast Rpd3 is required for growth and conidiation in several filamentous fungi (11).…”

PFP1 , a Gene Encoding an Epc-N Domain-Containing Protein, Is Essential for Pathogenicity of the Barley Pathogen Rhynchosporium commune

“…In addition, conidiation was strongly reduced. The FTL1 homolog TIG1 of the rice pathogen Magnaporthe oryzae was shown to be a component of an HDAC complex that also comprises Set3, Hos2, and Snt1 (29). A deletion mutant showed defective plant infection, reduced conidiation, and abnormal conidium morphology but only slightly reduced growth ex planta.…”

“…Furthermore, proteins modulating chromatin structure have been shown to be involved in controlling pathogenicity. The FTL1 gene of Fusarium graminearum (28) and the TIG1 gene of Magnaporthe oryzae (29), both of which encode transducin ␤-like components of a histone deacetylation (HDAC) complex, are defective in plant infection and conidiogenesis. Moreover, deletion of the HDC1 gene in Cochliobolus carbonum, which is related to Saccharomyces cerevisiae HOS2 HDAC, yielded mutants with reduced penetration efficiency and strongly reduced virulence (30).…”