title: Arabidopsis cell death in compatible and incompatible interactions with Alternaria brassicicola.
abstract: Two strains of necrotrophic Alternaria brassicicola, Ab40857 and Ab42464, are virulent on Korean cabbage and several wild types of Arabidopsis thaliana. Interaction between Ab42464 and Col-0 was compatible, whereas interaction between Ab40857 and Col-0 was incompatible. The loss of defense, no death (dnd) 1 function abrogated the compatibility between Ab42464 and Col-0, and the accelerated cell death (acd) 2 mutation attenuated the Col-0's resistance against Ab40857. These two fungal strains induced PR1 transcription in Col-0. Ab40857 accelerated transcription of PDF1.2, THI2.1, CAT, and POX by 12 h compared to those challenged with Ab42464. More abundant cell death was observed in Col-0 infected with Ab42464, however, callose deposition was evident in the incompatible interaction. Remarkably, Ab40857-infected areas of acd2-2 underwent rampant cell death and Ab42464 triggered callose production in dnd1-1. Furthermore, the incompatibility between Ab40857 and Col-0 was nullified by the coronatine-insensitive 1 (coi1) and phytoalexin-deficient 3 (pad3) mutations but not by nonexpresser of PR genes (npr1) and pad4. Ab40857 induced abundant cell death in pad3. Taken together, cell death during the early infection stage is a key determinant that discriminates between a compatible interaction and an incompatible one, and the resistance within Col-0 against Ab40857 is dependent on a defense-signaling pathway mediated by jasmonic acid and PAD3.
authors.affiliation: Rural Development Administration, National Academy of Agricultural Science, Suwon, 441-707, Korea.
authors.forename: Mukhamad
authors.initials: M
authors.lastname: Su'udi
authors.forename: Min Gab
authors.initials: MG
authors.lastname: Kim
authors.forename: Sang-Ryeol
authors.initials: SR
authors.lastname: Park
authors.forename: Duk-Ju
authors.initials: DJ
authors.lastname: Hwang
authors.forename: Shin-Chul
authors.initials: SC
authors.lastname: Bae
authors.forename: Il-Pyung
authors.initials: IP
authors.lastname: Ahn
mesh_terms: D000528:Alternaria / Q000472:pathogenicity / Q000502:physiology*; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000382:microbiology*; D016923:Cell Death / Q000235:genetics; D020869:Gene Expression Profiling; D054884:Host-Pathogen Interactions; D006861:Hydrogen Peroxide / Q000378:metabolism; D007211:Indoles / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology; D057865:Plant Immunity; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics / Q000382:microbiology; D013844:Thiazoles / Q000378:metabolism; D000094162:Phytoalexins
chemical_list: D006861:Hydrogen Peroxide; D007211:Indoles; D013844:Thiazoles; C102405:camalexin; D000094162:Phytoalexins