Beschreibung:
<jats:p>In barley leaves, 13‐lipoxygenases (13‐LOXs) are induced by salicylate (SA) and jasmonate. Here, we show by metabolic profiling that upon SA treatment, free linolenic acid and linoleic acid accumulate in a 10:1 ratio reflecting their relative occurrence in leaf tissues. Furthermore, 13‐LOX‐derived products are formed and specifically directed into the reductase branch of the LOX pathway leading mainly to the accumulation of (13<jats:italic>S</jats:italic>,9<jats:italic>Z</jats:italic>,11<jats:italic>E</jats:italic>,15<jats:italic>Z</jats:italic>)‐13‐hydroxy‐9,11,15‐octadecatrienoic acid (13‐HOT). Under these conditions, no accumulation of other products of the LOX pathway has been found. Moreover, exogenously applied 13‐HOT led to <jats:italic>PR1b</jats:italic> expression suggesting for the time a role of hydroxy polyenoic fatty acid derivatives in plant defense reactions.</jats:p>