Entomopathogenic fungi have been widely used as the main mycoinsecticide for controlling agricultural and forest pests.The effector molecules of these mycopathogens have evolved to adapt to their hosts.The role of fun...Entomopathogenic fungi have been widely used as the main mycoinsecticide for controlling agricultural and forest pests.The effector molecules of these mycopathogens have evolved to adapt to their hosts.The role of fungal effectors in evading the host immune system in insects remains mainly unclear.We characterized the widely distributed fungal effector necrosis-inducing-like secreted protein 1(NLS1)in the entomopathogenic fungus Metarhizium robertsii.Our findings revealed the presence of M.robertsii NLS1(MrNLS1)in host hemocytes during the early stage of hemocoel infection.MrNLS1 knock down(ΔMrNLS1)reduced fungal pathogenicity during infection and altered the expression of host immune genes.The molecular docking results and the yeast 2-hybrid assay confirmed that MrNLS1 interacts with the host defense protein Hdd11.The phylogenetic analysis indicated that Hdd11 is conserved across a broad range of Lepidoptera species.Knock down of hdd11 in Helicoverpa armigera,Bombyx mori,and Galleria mellonella markedly suppressed their immune responses against M.robertsii.However,no significant difference was observed in the mean lethal time between hdd11-knockdown Lepidoptera species infected withΔMrNLS1 and those infected with wild-type M.robertsii.Therefore,in Lepidoptera insects,Hdd11 is essential for fungal defense.In conclusion,M.robertsii infects Lepidoptera insects by targeting host Hdd11 through its protein MrNLS1,thereby suppressing the host immune response.Our findings clarify the molecular mechanisms underlying fungal infection pathogenesis.展开更多
基金supported by National Science Foundation of China(Grant No.32102274)Hefei Municipal Natural Science Foundation(202312).
文摘Entomopathogenic fungi have been widely used as the main mycoinsecticide for controlling agricultural and forest pests.The effector molecules of these mycopathogens have evolved to adapt to their hosts.The role of fungal effectors in evading the host immune system in insects remains mainly unclear.We characterized the widely distributed fungal effector necrosis-inducing-like secreted protein 1(NLS1)in the entomopathogenic fungus Metarhizium robertsii.Our findings revealed the presence of M.robertsii NLS1(MrNLS1)in host hemocytes during the early stage of hemocoel infection.MrNLS1 knock down(ΔMrNLS1)reduced fungal pathogenicity during infection and altered the expression of host immune genes.The molecular docking results and the yeast 2-hybrid assay confirmed that MrNLS1 interacts with the host defense protein Hdd11.The phylogenetic analysis indicated that Hdd11 is conserved across a broad range of Lepidoptera species.Knock down of hdd11 in Helicoverpa armigera,Bombyx mori,and Galleria mellonella markedly suppressed their immune responses against M.robertsii.However,no significant difference was observed in the mean lethal time between hdd11-knockdown Lepidoptera species infected withΔMrNLS1 and those infected with wild-type M.robertsii.Therefore,in Lepidoptera insects,Hdd11 is essential for fungal defense.In conclusion,M.robertsii infects Lepidoptera insects by targeting host Hdd11 through its protein MrNLS1,thereby suppressing the host immune response.Our findings clarify the molecular mechanisms underlying fungal infection pathogenesis.
