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Among these branches are the allene oxide synthase (AOS) branch, the hydroperoxide lyase (HPL) branch, the divinyl ether synthase (DES) branch and the epoxyalcohol synthase (EAS) branch ([6]). In the study of [3], initial expression of 13-LOX and 9-LOX genes following infection consisted of the induction of six of the twelve 13-LOX annotated genes and twelve of the nineteen 9-LOX annotated genes. Among the induced 9-LOX genes, only three were expressed by both typical and latent infections, but interestingly ten times more highly expressed upon typical infection than upon latent infection. [Extracted from the article]

Jasmonates are a family of oxylipin phytohormones regulating plant development and growth and mediating "defense versus growth" responses. The upstream JA biosynthetic precursor cis-(+)-12-oxo-phytodienoic acid (cis-OPDA) acts independently of CORONATIVE INSENSITIVE 1-mediated JA signaling in several stress-induced and developmental processes. However, its perception and metabolism are only partially understood. An isoleucine analog of the biologically active JA-Ile, OPDA-Ile, was detected years ago in wounded leaves of flowering plants, opening up the possibility that conjugation of cis-OPDA to amino acids might be a relevant mechanism for cis-OPDA regulation. Here, we extended the analysis of amino acid conjugates of cis-OPDA and identified naturally occurring OPDA-Val, OPDA-Phe, OPDA-Ala, OPDA-Glu, and OPDA-Asp accumulating in response to biotic and abiotic stress in Arabidopsis (Arabidopsis thaliana). The OPDA amino acid conjugates displayed cis-OPDA-related plant responses in a JA-Ile-dependent manner. We also showed that the synthesis and hydrolysis of cis-OPDA amino acid conjugates are mediated by members of the amidosynthetase GRETCHEN HAGEN 3 and the amidohydrolase INDOLE-3-ACETYL-LEUCINE RESISTANT 1/ILR1-like families. Thus, OPDA amino acid conjugates function in the catabolism or temporary storage of cis-OPDA in stress responses instead of acting as chemical signals per se., Competing Interests: Conflict of interest statement: None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society of Plant Biologists.)