HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

On the Cover: Role of ACX in Jasmonate Synthesis and Action

The plant hormone jasmonic acid (JA) serves diverse roles in plant developmental and defense-related processes. The β-oxidation stage of JA biosynthesis requires the peroxisomal enzyme acyl-CoA oxidase (ACX).An Arabidopsis (Arabidopsis thaliana) mutant that is defective in ACX1 and its closely related paralog, ACX5, is severely deficient in JA. Loss of JA biosynthetic capacity in acx1/5 double mutants results in decreased resistance to herbivore attack and reduced pollen viability. However, acx1/5 mutants accumulate JA in response to infection by the necrotrophic fungal pathogen Alternaria brassicicola, suggesting that other ACX isoforms can contribute to JA production. Thus, different types of biotic stress may induce JA synthesis via distinct enzymatic routes. The cover photograph shows a confocal image of a pollinated pistil on a plant that expresses peroxisomal-targeted yellow fluorescent protein under the control of the ACX1 promoter. Photograph by Abraham J.K. Koo. (See Schilmiller et al., pp. 812–824.)