title: A plant EPF-type zinc-finger protein, CaPIF1, involved in defence against pathogens.
abstract: SUMMARY To understand better the defence responses of plants to pathogen attack, we challenged hot pepper plants with bacterial pathogens and identified transcription factor-encoding genes whose expression patterns were altered during the subsequent hypersensitive response. One of these genes, CaPIF1 (Capsicum annuum Pathogen-Induced Factor 1), was characterized further. This gene encodes a plant-specific EPF-type protein that contains two Cys(2)/His(2) zinc fingers. CaPIF1 expression was rapidly and specifically induced when pepper plants were challenged with bacterial pathogens to which they are resistant. In contrast, challenge with a pathogen to which the plants are susceptible only generated weak CaPIF1 expression. CaPIF1 expression was also strongly induced in pepper leaves by the exogenous application of ethephon, an ethylene-releasing compound, and salicylic acid, whereas methyl jasmonate had only moderate effects. CaPIF1 localized to the nuclei of onion epidermis when expressed as a CaPIF1-smGFP fusion protein. Transgenic tobacco plants over-expressing CaPIF1 driven by the CaMV 35S promoter showed increased resistance to challenge with a tobacco-specific pathogen or non-host bacterial pathogens. These plants also showed constitutive up-regulation of multiple defence-related genes. Moreover, virus-induced silencing of the CaPIF1 orthologue in Nicotiana benthamiana enhanced susceptibility to the same host or non-host bacterial pathogens. These observations provide evidence that an EPF-type Cys(2)/His(2) zinc-finger protein plays a crucial role in the activation of the pathogen defence response in plants.
authors.affiliation: Plant Genomics Laboratory, Genome Research Center, KRIBB, PO Box 115, Yusung, Taejon, 305-600, Republic of Korea.
authors.forename: Sang-Keun
authors.initials: SK
authors.lastname: Oh
authors.forename: Jeong Mee
authors.initials: JM
authors.lastname: Park
authors.forename: Young Hee
authors.initials: YH
authors.lastname: Joung
authors.forename: Sanghyeob
authors.initials: S
authors.lastname: Lee
authors.forename: Eunsook
authors.initials: E
authors.lastname: Chung
authors.forename: Soo-Yong
authors.initials: SY
authors.lastname: Kim
authors.forename: Seung Hun
authors.initials: SH
authors.lastname: Yu
authors.forename: Doil
authors.initials: D
authors.lastname: Choi