title: PdSNF1, a sucrose non-fermenting protein kinase gene, is required for Penicillium digitatum conidiation and virulence.
abstract: The sucrose non-fermenting protein kinase 1 gene (SNF1) regulates the derepression of glucose-repressible genes in microorganisms. In this study, we cloned an ortholog of SNF1 from Penicillium digitatum and characterized its functions through a gene knock-out strategy. Growth of the PdSNF1 mutant (ΔPdSNF1) on the synthetic medium (SM) supplemented with pectin or polygalacturonic acid was severely disturbed. The appearance of disease symptoms on the ΔPdSNF1 mutant-inoculated citrus fruits was significantly delayed as well. The expression levels of the cell wall-degrading enzyme (CWDE) genes (e.g., XY1, PL1, PNL1, and EXPG2) after pectin induction were up-regulated in wild type, but unchanged or less up-regulated in the ΔPdSNF1 mutant. During infection in citrus fruit, the up-regulation of XY1 was delayed in the ΔPdSNF1 mutant. Disruption of PdSNF1 also resulted in impaired conidiation and caused malformation of the conidiophore structures. In addition, the expression of BrlA, a gene that regulates conidiophore development, was significantly impaired in the ΔPdSNF1 mutant. However, the expression of FadA, encoding the α-subunit of a heterotrimeric G protein, was up-regulated in this mutant. Collectively, our results demonstrate that the PdSNF1 plays a role in adapting P. digitatum to alternative carbon sources. Its involvements in the virulence of P. digitatum is probably via regulation of the expression of CWDE genes; and it is also involved in conidiation, probably through activation of the conidiation signaling pathway while inactivating the mycelial growth-signaling pathway.
authors.affiliation: Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China.
authors.forename: Tianyuan
authors.initials: T
authors.lastname: Zhang
authors.forename: Xuepeng
authors.initials: X
authors.lastname: Sun
authors.forename: Qian
authors.initials: Q
authors.lastname: Xu
authors.forename: Congyi
authors.initials: C
authors.lastname: Zhu
authors.forename: Qiongzhi
authors.initials: Q
authors.lastname: Li
authors.forename: Hongye
authors.initials: H
authors.lastname: Li
mesh_terms: D002957:Citrus / Q000382:microbiology; D003001:Cloning, Molecular; D003470:Culture Media / Q000737:chemistry; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics; D055786:Gene Knockout Techniques; D008969:Molecular Sequence Data; D010407:Penicillium / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D010935:Plant Diseases / Q000382:microbiology*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013172:Spores, Fungal / Q000254:growth & development*; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D003470:Culture Media; D005656:Fungal Proteins; D037521:Virulence Factors; C071570:SNF1-related protein kinases; D017346:Protein Serine-Threonine Kinases