title: Involvement of cathepsin B in the plant disease resistance hypersensitive response.
abstract: A diverse range of plant proteases are implicated in pathogen perception and in subsequent signalling and execution of disease resistance. We demonstrate, using protease inhibitors and virus-induced gene silencing (VIGS), that the plant papain cysteine protease cathepsin B is required for the disease resistance hypersensitive response (HR). VIGS of cathepsin B prevented programmed cell death (PCD) and compromised disease resistance induced by two distinct non-host bacterial pathogens. It also suppressed the HR triggered by transient co-expression of potato R3a and Phytophthora infestans Avr3a genes. However, VIGS of cathepsin B did not compromise HR following recognition of Cladosporium fulvum AVR4 by tomato Cf-4, indicating that plant PCD can be independent of cathepsin B. The non-host HR to Erwinia amylovora was accompanied by a transient increase in cathepsin B transcript level and enzymatic activity and induction of the HR marker gene Hsr203. VIGS of cathepsin B significantly reduced the induction of Hsr203 following E. amylovora challenge, further demonstrating a role for this protease in PCD. Whereas cathepsin B is often relocalized from the lysosome to the cytosol during animal PCD, plant cathepsin B is secreted into the apoplast, and is activated upon secretion in the absence of pathogen challenge.
authors: Plant Pathology Programme, Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK.
authors: Eleanor M
authors: EM
authors: Gilroy
authors: Ingo
authors: I
authors: Hein
authors: Renier
authors: R
authors: van der Hoorn
authors: Petra C
authors: PC
authors: Boevink
authors: Eduard
authors: E
authors: Venter
authors: Hazel
authors: H
authors: McLellan
authors: Florian
authors: F
authors: Kaffarnik
authors: Katarina
authors: K
authors: Hrubikova
authors: Jane
authors: J
authors: Shaw
authors: Maria
authors: M
authors: Holeva
authors: Eduardo C
authors: EC
authors: López
authors: Orlando
authors: O
authors: Borras-Hidalgo
authors: Leighton
authors: L
authors: Pritchard
authors: Gary J
authors: GJ
authors: Loake
authors: Christophe
authors: C
authors: Lacomme
authors: Paul R J
authors: PR
authors: Birch
mesh_terms: D001483:Base Sequence; D002401:Cathepsin B / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers; D020868:Gene Silencing; D005819:Genetic Markers; D010935:Plant Diseases / Q000382:microbiology* / Q000821:virology; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; D005819:Genetic Markers; D002401:Cathepsin B