13(S)-HpOTrE is a monohydroperoxy polyunsaturated fatty acid produced in soybeans by the action of soybean LO-2 on esterified α-linolenic acid.[1] Incubation of soybean seedling biomembranes with soybean LO-2 catalyzes the formation of both 9- and 13-HpOTrE in a molar ratio of 10:1.1 In plants, 13(S)-HpOTrE can be metabolized by the hydroperoxide lyase pathway producing aldehyde and oxoacid fragments, or by the hydroperoxide dehydratase pathway producing jasmonic acid.[2],[3],[4] Treatment of tomato leaves with 13-HpOTrE causes induction of proteinase inhibitors, simulating the normal response to wounding.5 This data suggests that in plants 13(S)-HpOTrE may participate in a lipid-based signalling system initiated by insect and pathogen attack.

Reference:
[1]. Maccarrone, M., van Aarle, P.G.M., Veldink, G.A., et al. In vitro oxygenation of soybean biomembranes by lipoxygenase-2. Biochimica et Biophysica Acta 1190, 164-169 (1994).
[2]. Vick, B.A. Oxygenated fatty acids of the lipoxygenase pathway. Lipid Metabolism in Plants 167-191 (1993).
[3]. Salch, Y.P., Grove, M.J., Takamura, H., et al. Characterization of a C-5,13-cleaving enzyme of 13(S)-hydroperoxide of linolenic acid by soybean seed. Plant Physiology 108, 1211-1218 (1995).
[4]. Simpson, T.D., and Garnder, H.W. Allene oxide synthase and allene oxide cyclase, enzymes of the jasmonic acid pathway, localized in Glycine max tissues. Plant Physiology 108, 199-202 (1995).
[5]. Farmer, E.E., and Ryan, C.A. Octadecanoid precursors of jasmonic acid activate the synthesis of wound-inducible proteinase inhibitors. Plant Cell 4, 129-134 (1992).