title: Vital role for the J-domain protein Mdj1 in asexual development, multiple stress tolerance, and virulence of Beauveria bassiana.
abstract: Mdj1 is a member of the Hsp40 family containing a DnaJ or J domain. Here, we have examined the functions of an Mdj1 orthologue (56.68 kDa) in Beauveria bassiana, a filamentous fungal insect pathogen widely applied in biological control of insect pests. Deletion of mdj1 in B. bassiana resulted in significant growth defects on a variety of complex and minimal media. The Δmdj1 mutant exhibited not only a drastic reduction (92 %) in aerial conidiation during optimal cultivation but also a remarkable decrease (77 %) in submerged blastospore production. Compared to wild-type, the deletion mutant was significantly more sensitive to the stresses of cell wall perturbation, high osmolarity, oxidation, carbendazim fungicide, several metal ions, and acidic/alkaline pH during conidial germination and/or colony growth. In the mutant, conidial thermotolerance and UV-B resistance decreased by 61 and 25 %, respectively, and virulence to Galleria mellonella larvae was largely attenuated. Transcript levels of many phenotype-related genes were drastically suppressed in the absence of mdj1, accompanied with impaired cell walls and reduced intracellular anti-stress molecules, including superoxide dismutases, catalases, glycerol, trehalose, and mannitol. These data indicate that Mdj1 plays a vital role in normal fungal development and contributes significantly to the biological control potential of B. bassiana against insect pests.
authors: Key Laboratory of Tropical Marine Bio-resources and Ecology, RNAM Center for Marine Microbiology, Guangdong Key Laboratory of Marine Material Medical, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou, 510301, China.|Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China.
authors: Jie
authors: J
authors: Wang
authors: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China.
authors: Sheng-Hua
authors: SH
authors: Ying
authors: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China.
authors: Yue
authors: Y
authors: Hu
authors: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China. mgfeng@zju.edu.cn.
authors: Ming-Guang
authors: http://orcid.org/0000-0002-2657-0293
authors: MG
authors: Feng
mesh_terms: D000818:Animals; D000935:Antifungal Agents; D052982:Beauveria / Q000187:drug effects / Q000254:growth & development* / Q000502:physiology* / Q000528:radiation effects; D001681:Biological Assay; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D050956:HSP40 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006358:Hot Temperature; D007915:Lepidoptera / Q000382:microbiology; D013172:Spores, Fungal / Q000254:growth & development; D013312:Stress, Physiological; D016019:Survival Analysis; D014466:Ultraviolet Rays; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D000935:Antifungal Agents; D005656:Fungal Proteins; D050956:HSP40 Heat-Shock Proteins; D037521:Virulence Factors
keywords: Asexual development; Biological control potential; Cell wall integrity; Entomopathogenic fungi; J-domain proteins; Multiple stress tolerance