title: A critical role of STAYGREEN/Mendel's I locus in controlling disease symptom development during Pseudomonas syringae pv tomato infection of Arabidopsis.
abstract: Production of disease symptoms represents the final phase of infectious diseases and is a main cause of crop loss and/or marketability. However, little is known about the molecular basis of disease symptom development. In this study, a genetic screening was conducted to identify Arabidopsis (Arabidopsis thaliana) mutants that are impaired specifically in the development of disease symptoms (leaf chlorosis and/or necrosis) after infection with the bacterial pathogen Pseudomonas syringae pv tomato (Pst) DC3000. An ethyl methanesulfonate-induced Arabidopsis mutant (no chlorosis1 [noc1]) was identified. In wild-type plants, the abundance of chlorophylls decreased markedly after Pst DC3000 infection, whereas the total amount of chlorophylls remained relatively unchanged in the noc1 mutant. Interestingly, noc1 mutant plants also exhibited reduced disease symptoms in response to the fungal pathogen Alternaria brassicicola. Genetic and molecular analyses showed that the nuclear gene STAYGREEN (SGR; or Mendel's I locus) is mutated (resulting in the aspartic acid to tyrosine substitution at amino acid position 88) in noc1 plants. Transforming wild-type SGR cDNA into the noc1 mutant rescued the chlorosis phenotype in response to Pst DC3000 infection. The SGR transcript was highly induced by Pst DC3000, A. brassicicola, or coronatine (COR), a bacterial phytotoxin that promotes chlorosis. The induction of SGR expression by COR is dependent on COI1, a principal component of the jasmonate receptor complex. These results suggest that pathogen/COR-induced expression of SGR is a critical step underlying the development of plant disease chlorosis.
authors: Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824.
authors: Christy
authors: C
authors: Mecey
authors: Paula
authors: P
authors: Hauck
authors: Marisa
authors: M
authors: Trapp
authors: Nathan
authors: N
authors: Pumplin
authors: Anne
authors: A
authors: Plovanich
authors: Jian
authors: J
authors: Yao
authors: Sheng Yang
authors: SY
authors: He
mesh_terms: D000528:Alternaria / Q000472:pathogenicity*; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping; D003517:Cyclopentanes / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D056426:Genetic Loci; D007192:Indenes / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D054883:Oxylipins / Q000378:metabolism; D010641:Phenotype; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D010937:Plant Growth Regulators / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D044224:Pseudomonas syringae / Q000472:pathogenicity*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014774:Virulence
chemical_list: D000596:Amino Acids; D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D018076:DNA, Complementary; D007192:Indenes; D054883:Oxylipins; D010937:Plant Growth Regulators; C058487:coronatine; C011006:jasmonic acid