title: The autophagy-related gene BcATG1 is involved in fungal development and pathogenesis in Botrytis cinerea.
abstract: Autophagy, a ubiquitous intracellular degradation process, is conserved from yeasts to humans. It serves as a major survival function during nutrient depletion stress and is crucial for correct growth and differentiation. In this study, we characterized an atg1 orthologue Bcatg1 in the necrotrophic plant pathogen Botrytis cinerea. Quantitative real-time polymerase chain reaction (qRT-PCR) assays showed that the expression of BcATG1 was up-regulated under carbon or nitrogen starvation conditions. BcATG1 could functionally restore the survival defects of the yeast ATG1 mutant during nitrogen starvation. Deletion of BcATG1 (ΔBcatg1) inhibited autophagosome accumulation in the vacuoles of nitrogen-starved cells. ΔBcatg1 was dramatically impaired in vegetative growth, conidiation and sclerotial formation. In addition, most conidia of ΔBcatg1 lost the capacity to form the appressorium infection structure and failed to penetrate onion epidermis. Pathogenicity assays showed that the virulence of ΔBcatg1 on different host plant tissues was drastically impaired, which was consistent with its inability to form an appressorium. Moreover, lipid droplet accumulation was significantly reduced in the conidia of ΔBcatg1, but the glycerol content was increased. All of the defects of ΔBcatg1 were complemented by re-introduction of an intact copy of the wild-type BcATG1 into the mutant. These results indicate that BcATG1 plays a critical role in numerous developmental processes and is essential to the pathogenesis of B. cinerea.
authors.affiliation: College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Weichao
authors.initials: W
authors.lastname: Ren
authors.affiliation: College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Wenyong
authors.initials: W
authors.lastname: Shao
authors.affiliation: College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Yalan
authors.initials: Y
authors.lastname: Yang
authors.affiliation: College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Mingguo
authors.initials: M
authors.lastname: Zhou
authors.affiliation: College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: Changjun
authors.initials: C
authors.lastname: Chen
mesh_terms: D001343:Autophagy / Q000235:genetics*; D020171:Botrytis / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity* / Q000648:ultrastructure; D002103:Cadaverine / Q000031:analogs & derivatives / Q000378:metabolism; D002244:Carbon / Q000494:pharmacology; D018553:Cucumis sativus / Q000382:microbiology; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D050356:Lipid Metabolism; D009154:Mutation / Q000235:genetics; D009584:Nitrogen / Q000494:pharmacology; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000382:microbiology; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013172:Spores, Fungal / Q000502:physiology
chemical_list: D002244:Carbon; C008542:monodansylcadaverine; D002103:Cadaverine; D009584:Nitrogen
keywords: BcATG1; Botrytis cinerea; autophagy; development; pathogenesis