title: MaSnf1, a sucrose non-fermenting protein kinase gene, is involved in carbon source utilization, stress tolerance, and virulence in Metarhizium acridum.
abstract: The protein kinase sucrose non-fermenting-1(Snf1) regulates the derepression of glucose-repressible genes and plays a major role in carbon source utilization. In this study, MaSnf1, a sucrose non-fermenting protein kinase gene, has been identified from the entomopathogenic fungus Metarhizium acridum, which has a great potential as a biocontrol agent. The functions of MaSnf1 were characterized using gene disruption and complementation strategies. Disruption of MaSnf1 reduced the conidial yield and delayed the conidial germination on potato dextrose agar (PDA) medium. MaSnf1 is also important for response to ultraviolet radiation and heat shock stress and carbon source utilization in M. acridum. Bioassays by topical inoculation and intrahemocoel injection showed that the MaSnf1 deletion mutant exhibited greatly reduced pathogenicity. The reduced expression level of chitinase gene (Chi) and protease gene (Pr1A) in MaSnf1-disruption transformant (ΔMaSnf1) most likely affects the initial penetration into its host. Additionally, the reduced expression level of acidic trehalase gene (ATM1) probably causes a decline in growth rate in insect hemolymph. Inactivation of MaSnf1 led to a significant decrease in virulence, probably owing to reduction in conidial germination, and appressorium formation, impairment in penetration, and decrease in growth rate in insect hemolymph.
authors.affiliation: Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing, 400045, People's Republic of China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Ming
authors.forename: Qinglv
authors.initials: Q
authors.lastname: Wei
authors.forename: Kai
authors.initials: K
authors.lastname: Jin
authors.forename: Yuxian
authors.initials: Y
authors.lastname: Xia
mesh_terms: D000818:Animals; D002244:Carbon / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D015966:Gene Expression Regulation, Fungal; D055786:Gene Knockout Techniques; D005816:Genetic Complementation Test; D006358:Hot Temperature; D007313:Insecta / Q000382:microbiology; D052981:Metarhizium / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D013172:Spores, Fungal / Q000254:growth & development; D013312:Stress, Physiological; D014466:Ultraviolet Rays; D014774:Virulence
chemical_list: D003470:Culture Media; D002244:Carbon; C071570:SNF1-related protein kinases; D017346:Protein Serine-Threonine Kinases