RCH1, a locus in Arabidopsis that confers resistance to the hemibiotrophic fungal pathogen Colletotrichum higginsianum

• Published in: Molecular plant-microbe interactions Vol. 17; no. 7; pp. 749 - 762
• Main Authors: Narusaka, Y, Narusaka, M, Park, P, Kubo, Y, Hirayama, T, Seki, M, Shiraishi, T, Ishida, J, Nakashima, M, Enju, A
• Format: Journal Article
• Language: English
• Published: St Paul, MN APS Press 01.07.2004; American Phytopathological Society; The American Phytopathological Society
• Subjects: anthracnose; Arabidopsis - genetics; Arabidopsis - microbiology; Arabidopsis - ultrastructure; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; Biological and medical sciences; Brassicaceae; collectotrichum higginsianum; Colletotrichum - growth & development; Colletotrichum higginsianum; complementary DNA; Cyclopentanes - pharmacology; disease resistance; ethylene; Ethylenes - pharmacology; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; gene expression regulation; host-pathogen relationships; hypersensitive response; Immunity, Innate - drug effects; Immunity, Innate - genetics; Indoles - metabolism; jasmonic acid; messenger RNA; Microscopy, Electron; Oligonucleotide Array Sequence Analysis; Oxylipins; Phyllachorales; Phylogeny; Phytopathology. Animal pests. Plant and forest protection; Plant Diseases - genetics; Plant Diseases - microbiology; Plant Growth Regulators - pharmacology; Plant Leaves - genetics; Plant Leaves - microbiology; Plant Leaves - ultrastructure; plant pathogenic fungi; plant proteins; reactive oxygen species; Reactive Oxygen Species - metabolism; resistance mechanisms; salicylic acid; Salicylic Acid - pharmacology; signal transduction; Signal Transduction - drug effects; Signal Transduction - physiology; Thiazoles - metabolism; Fungi; Resistance; Microbiology; Cruciferae; Arabidopsis; Dicotyledones; Angiospermae; Spermatophyta; Fungi Imperfecti; Colletotrichum; Thallophyta
• ISSN: 0894-0282; 1943-7706
• DOI: 10.1094/MPMI.2004.17.7.749

When challenged with the crucifer pathogen Colletotrichum higginsianum, Arabidopsis thaliana ecotype Columbia (Col-0) was colonized by the fungus within 2 to 3 days, developing brown necrotic lesions surrounded by a yellow halo. Lesions spread from the inoculation site within 3 to 4 days, and subsequently continued to expand until they covered the entire leaf. Electron microscopy confirmed that C. higginsianum is a hemibiotroph on Arabidopsis, feeding initially on living cells as a biotroph before switching to a necrotrophic mode of growth. A collection of 37 ecotypes of Arabidopsis varied in their responses to infection by C. higginsianum. The ecotype Eil-0 was highly resistant, with symptoms limited to necrotic flecking and with only very limited fungal colonization. Analyses suggested that the hypersensitive response and reactive oxygen species may be important in this defense response. Expression analyses with cDNA microarrays indicated that the defense reaction depends primarily on the jasmonic acid- and ethylene-dependent signaling pathways and, to a lesser extent, on the salicylate-dependent pathway. Crosses between the Eil-0 and Col-0 ecotypes suggested that the resistance in Eil-0 was dominant and was conferred by a single locus, which we named RCH1. RCH1 is the first resistance locus to be identified from Arabidopsis against the hemibiotrophic fungus genus Colletotrichum.