Plant lipoxygenase may be involved in a number of diverse aspects of plant physiology including growth and development, pest resistance, and senescence or responses to wounding. It catalyzes the hydroperoxidation of lipids containing a cis,cis-1,4-pentadiene structure. (9Z,12Z)-octadecadienoate + O2 = (9S)-hydroperoxy-(10E,12Z)-octadecadienoate Binds 1 Fe cation per subunit. Iron is tightly bound. Lipid metabolism; oxylipin biosynthesis. Monomer. In both quiescent and germinating seeds. With linoleate as substrate, lipoxygenase 1 shows a specificity for carbon 9 as the site for hydroperoxidation (in contrast to lipoxygenase 2, which shows a preference for carbon 13). Belongs to the lipoxygenase family.