Mitogen-Activated Protein Kinases SvPmk1 and SvMps1 Are Critical for Abiotic Stress Resistance, Development and Pathogenesis of Sclerotiophoma versabilis

Abstract

Mitogen-activated protein kinase (MAPK) signaling pathways are evolutionarily conserved in eukaryotes and modulate responses to both internal and external stimuli. Pmk1 and Mps MAPK pathways regulate stress tolerance, vegetative growth and cell wall integrity in Saccharomyces cerevisiae and Pyricularia oryzae. Here, we deployed genetic and cell biology strategies to investigate the roles of the orthologs of Pmk1 and Mps1 in Sclerotiophoma versabilis (herein referred to as SvPmk1 and SvMps1, respectively). Our results showed that SvPmk1 and SvMps1 are involved in hyphal development, asexual reproduction and pathogenesis in S. versabilis. We found that ∆Svpmk1 and ∆Svmps1 mutants have significantly reduced vegetative growths on PDA supplemented with osmotic stress-inducing agents, compared to the wild type, with ∆Svpmps1 being hypersensitive to hydrogen peroxide. The two mutants failed to produce pycnidia and have reduced pathogenicity on Pseudostellaria heterophylla. Unlike SvPmk1, SvMps1 was found to be indispensable for the fungal cell wall integrity. Confocal microscopic analyses revealed that SvPmk1 and SvMps1 are ubiquitously expressed in the cytosol and nucleus. Taken together, we demonstrate here that SvPmk1 and SvMps1 play critical roles in the stress resistance, development and pathogenesis of S. versabilis.

FsCGBP, a Cutinase G-Box Binding Protein, Regulates the Growth, Development, and Virulence of Fusarium sacchari, the Pathogen of Sugarcane Pokkah Boeng Disease

“…MAPK cascade pathways, which mediate cellular responses to environmental and physiological signals in eukaryotes, are broadly conserved [22]. Three types of MAPK signaling pathways have been reported in plant pathogenic fungi, namely, the FUS3/KSS1, SLT2, and HOG1 pathways, which play crucial roles in fungal development, stress responses, and virulence [22,[38][39][40][41][42][43]. In this study, the transcription levels of FsHOG1, Fs-MGV1, and FsGPMK1 in the ∆FsCGBP strains were significantly lower than those in the WT strain FF001.…”

Fimbrin associated with Pmk1 to regulate the actin assembly during Magnaporthe oryzae hyphal growth and infection

“…However, in most plant pathogenic fungi, only three MAPK genes orthologous to Hog1, Fus3/Kss1, and Slt2 (Jiang et al 2018 ) are present. Pmk1 is an orthologue of Fus/Kss1 and was suggested to be critical for fungal development and appressorium formation in appressorium-forming fungi, including the rice blast fungus M. oryzae , Colletotrichum lagenarium , and Colletotrichum gloeosporioides (Xu and Hamer 1996 ; Takano et al 2000 ; He et al 2017 ; Abah et al 2023 ). Mutants of PMK1 in M. oryzae fail to construct specialized infection structures known as appressorium and fail to develop invasive hyphae in rice plants (Xu and Hamer 1996 ).…”