JXB Advance Access published online on December 10, 2008
Journal of Experimental Botany, doi:10.1093/jxb/ern277
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REVIEW-ARTICLE |
Class III peroxidases in plant defence reactions
1Department of Plant Biology, Faculty of Biology, University of Murcia, Campus de Espinardo, E-30100 Murcia, Spain
2Departamento de Agroquimica y Bioquimica, Universidad de Alicante, Campus de San Vicente del Raspeig, E-03080 Alicante, Spain
To whom correspondence should be addressed: E-mail: mpedreno{at}um.es
When plants are attacked by pathogens, they defend themselves with an arsenal of defence mechanisms, both passive and active. The active defence responses, which require de novo protein synthesis, are regulated through a complex and interconnected network of signalling pathways that mainly involve three molecules, salicylic acid (SA), jasmonic acid (JA), and ethylene (ET), and which results in the synthesis of pathogenesis-related (PR) proteins. Microbe or elicitor-induced signal transduction pathways lead to (i) the reinforcement of cell walls and lignification, (ii) the production of antimicrobial metabolites (phytoalexins), and (iii) the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS). Among the proteins induced during the host plant defence, class III plant peroxidases (EC 1.11.1.7 [EC] ; hydrogen donor: H2O2 oxidoreductase, Prxs) are well known. They belong to a large multigene family, and participate in a broad range of physiological processes, such as lignin and suberin formation, cross-linking of cell wall components, and synthesis of phytoalexins, or participate in the metabolism of ROS and RNS, both switching on the hypersensitive response (HR), a form of programmed host cell death at the infection site associated with limited pathogen development. The present review focuses on these plant defence reactions in which Prxs are directly or indirectly involved, and ends with the signalling pathways, which regulate Prx gene expression during plant defence. How they are integrated within the complex network of defence responses of any host plant cell will be the cornerstone of future research.
Key words: Ethylene, jasmonic acid, lignification, peroxidases, phytoalexin, reactive nitrogen species, reactive oxygen species, salicylic acid
* These authors contributed equally to this review.
Received 12 August 2008; Revised 8 October 2008 Accepted 14 October 2008