title: A RACK1-like protein regulates hyphal morphogenesis, root entry and in vivo virulence in Verticillium dahliae.
abstract: To identify key genes expressed in Verticillium dahliae in early stages of infection of cotton roots, spore suspensions of eight V. dahliae isolates with different virulence levels were induced by cotton roots and genes expressed in these isolates during the early stages of infection were profiled. A gene that was differentially expressed between highly and less virulent strains was identified. Cloning and bioinformatics analysis of the gene suggested that it belongs to the putative Gβ-like/RACK1 protein family, and has seven WD40 domains. Targeted deletion of the gene revealed that it controls a number of growth-related phenotypes, including conidia and microsclerotia production, normal spore germination and hyphal development. RACK1 is a component of eukaryotic ribosomes, and here we found by qRT-PCR that disruption of RACK1 in V. dahliae (designated VdRACK1) significantly altered the transcriptional levels of other ribosomal proteins, suggesting possible global effects of VdRACK1 deletion on the protein translation of other genes. VdRACK1-null mutants lost the ability to penetrate intact cotton roots. However, the mutant strain was able to infect root-wounded cotton plants and, intriguingly, resulted in a hypervirulent phenotype, implicating a role for VdRACK1 in the restriction of rampant growth within the plant.
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yuan
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Yaxin
authors.initials: Y
authors.lastname: Su
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Crop Genetics & Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Yigao
authors.initials: Y
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Crop Genetics & Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Wangzhen
authors.initials: W
authors.lastname: Guo
authors.affiliation: College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: xywang@njau.edu.cn.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Wang
mesh_terms: D015966:Gene Expression Regulation, Fungal; D025301:Hyphae / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity; D009024:Morphogenesis / Q000235:genetics; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D018517:Plant Roots / Q000382:microbiology; D000075370:Receptors for Activated C Kinase / Q000235:genetics*; D017384:Sequence Deletion; D013172:Spores, Fungal / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity; D020172:Verticillium / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity
chemical_list: D000075370:Receptors for Activated C Kinase
keywords: Hypervirulence; RACK1 (Receptor for Activated C-kinase); RAPD (Randomly Amplified Polymorphic DNA); Verticillium dahliae