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. With linoleate as substrate, L-1 shows a preference for carbon 13 as the site for hydroperoxidation (in contrast to L-2 and L-3, which utilize either carbon 9 or 13). At pH above 8.5, only (9Z,11E,13S)-13-hydroperoxyoctadeca-9,11-dienoate is produced, but as the pH decreases, the proportion of (9S)-hydroperoxide increases linearly until at pH 6.0 it represents about 25 % of the products