title: Molecular characterization and functional analysis of a necrosis- and ethylene-inducing, protein-encoding gene family from Verticillium dahliae.
abstract: Verticillium dahliae Kleb. is a hemibiotrophic, phytopathogenic fungus that causes wilt disease in a wide range of crops, including cotton. Successful host colonization by hemibiotrophic pathogens requires the induction of plant cell death to provide the saprophytic nutrition for the transition from the biotrophic to the necrotrophic stage. In this study, we identified a necrosis-inducing Phytophthora protein (NPP1) domain-containing protein family containing nine genes in a virulent, defoliating isolate of V. dahliae (V592), named the VdNLP genes. Functional analysis demonstrated that only two of these VdNLP genes, VdNLP1 and VdNLP2, encoded proteins that were capable of inducing necrotic lesions and triggering defense responses in Nicotiana benthamiana, Arabidopsis, and cotton plants. Both VdNLP1 and VdNLP2 induced the wilting of cotton seedling cotyledons. However, gene-deletion mutants targeted by VdNLP1, VdNLP2, or both did not affect the pathogenicity of V. dahliae V592 in cotton infection. Similar expression and induction patterns were found for seven of the nine VdNLP transcripts. Through a comparison of the conserved amino acid residues of VdNLP with different necrosis-inducing activities, combined with mutagenesis-based analyses, we identified several novel conserved amino acid residues, in addition to the known conserved heptapeptide GHRHDWE motif and the cysteine residues of the NPP domain-containing protein, that are indispensable for the necrosis-inducing activity of the VdNLP2 protein.
authors.affiliation: State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Bang-Jun
authors.initials: BJ
authors.lastname: Zhou
authors.forename: Pei-Song
authors.initials: PS
authors.lastname: Jia
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.forename: Hui-Shan
authors.initials: HS
authors.lastname: Guo
mesh_terms: D000595:Amino Acid Sequence; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D005030:Ethylenes / Q000494:pharmacology; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal / Q000235:genetics; D003368:Gossypium / Q000382:microbiology*; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D009336:Necrosis; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D010937:Plant Growth Regulators / Q000494:pharmacology; D018515:Plant Leaves / Q000382:microbiology; D017434:Protein Structure, Tertiary; D036226:Seedlings / Q000382:microbiology; D016415:Sequence Alignment; D017384:Sequence Deletion; D014026:Nicotiana / Q000382:microbiology; D020172:Verticillium / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity
chemical_list: D018076:DNA, Complementary; D004271:DNA, Fungal; D005030:Ethylenes; D005656:Fungal Proteins; D010937:Plant Growth Regulators; C036216:ethylene