title: MaHog1, a Hog1-type mitogen-activated protein kinase gene, contributes to stress tolerance and virulence of the entomopathogenic fungus Metarhizium acridum.
abstract: Fungal biocontrol agents have great potential in integrated pest management. However, poor efficacy and sensitivity to various adverse factors have hampered their wide application. In eukaryotic cells, Hog1 kinase plays a critical role in stress responses. In this study, MaHog1 (GenBank accession no. EFY85878), encoding a member of the Hog1/Sty1/p38 mitogen-activated protein kinase family in Metarhizium (Me.) acridum, was identified. Targeted gene disruption was used to analyse the role of MaHog1 in virulence and tolerance of adverse factors. Mutants with MaHog1 depletion showed increased sensitivity to high osmotic stress, high temperature and oxidative stress, and exhibited remarkable resistance to cell wall-disturbing agents. These results suggest that Hog1 kinase has a conserved function in regulating multistress responses among fungi, and that MaHog1 might influence cell wall biogenesis in Me. acridum. Bioassays conducted with topical inoculation and intrahaemocoel injection revealed that MaHog1 is required for both penetration and postpenetration development of Me. acridum. MaHog1 disruption resulted in a significant reduction in virulence, likely due to the combination of a decrease in conidial germination, a reduction in appressorium formation and a decline in growth rate in insect haemolymph, which might be caused by impairing fungal tolerance of various stresses during infection.
authors.affiliation: Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing 400030, PR China.|Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 400030, PR China.|Genetic Engineering Research Center, School of Bioengineering, Chongqing University, Chongqing 400030, PR China.
authors.forename: Kai
authors.initials: K
authors.lastname: Jin
authors.affiliation: Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing 400030, PR China.|Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 400030, PR China.|Genetic Engineering Research Center, School of Bioengineering, Chongqing University, Chongqing 400030, PR China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Ming
authors.affiliation: Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing 400030, PR China.|Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 400030, PR China.|Genetic Engineering Research Center, School of Bioengineering, Chongqing University, Chongqing 400030, PR China.
authors.forename: Yu Xian
authors.initials: YX
authors.lastname: Xia
mesh_terms: D000818:Animals; D015966:Gene Expression Regulation, Fungal; D055786:Gene Knockout Techniques; D018390:Gene Targeting; D006358:Hot Temperature; D007313:Insecta; D052981:Metarhizium / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D009997:Osmotic Pressure; D018384:Oxidative Stress; D015398:Signal Transduction; D013312:Stress, Physiological; D014774:Virulence
chemical_list: D020928:Mitogen-Activated Protein Kinases