Roles of the reactive oxygen species-generating peroxidase reactions in plant defense and growth induction - PubMed (original) (raw)

Review

Roles of the reactive oxygen species-generating peroxidase reactions in plant defense and growth induction

T Kawano. Plant Cell Rep. 2003 Jun.

Abstract

Extracellularly secreted plant peroxidases (POXs) are considered to catalyze the generation of reactive oxygen species (ROS) coupled to oxidation of plant hormone indole-3-acetic acid (IAA) and defense-related compounds salicylic acid (SA), aromatic monoamines (AMAs) and chitooligosaccharides (COSs). This review article consists of two parts, which describe H(2)O(2)-dependent and H(2)O(2)-independent mechanisms for ROS generation, respectively. Recent studies have shown that plant POXs oxidize SA, AMAs and COSs in the presence of H(2)O(2) via a conventional POX cycle, yielding the corresponding radical species, such as SA free radicals. These radical species may react with oxygen, and superoxide (O(2)(.-)) is produced. Through the series of reactions 2 moles of O(2)(.-) can be formed from 1 moles of H(2)O(2), thus leading to oxidative burst. It has been revealed that the ROS induced by SA, AMAs and COSs triggers the increase in cytosolic Ca(2+) concentration. Actually POXs transduce the extracellular signals into the redox signals that eventually stimulate the intracellular Ca(2+) signaling required for induction of defense responses. On the other hand, IAA can react with oxygen and plant POXs in the absence of H(2)O(2), by forming the ternary complex enzyme-IAA-O(2), which readily dissociates into enzyme, IAA radicals and O(2)(.-). This article covers the recent reports showing that extracellularly produced hydroxy radicals derived from O(2)(.-) mediate the IAA-induced cell elongation. Here a novel model for IAA signaling pathway mediated by extracellular ROS produced by cell-wall POXs is proposed. In addition, possible controls of the IAA-POX reactions by a fungal alkaloid are discussed.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Plant Cell. 1994 Sep;6(9):1301-1310 - PubMed
    1. Plant Physiol. 1999 Sep;121(1):147-52 - PubMed
    1. Planta. 2002 Oct;215(6):1022-30 - PubMed
    1. Phytochemistry. 1992 May;31(5):1747-52 - PubMed
    1. Mol Plant Microbe Interact. 2001 Jun;14(6):725-36 - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources