The early-13-hydroxylation pathway from
GA12 to GA8 of GA
biosynthesis and deactivation in spinach. GA53 is
converted to GA20 by GA 20-oxidase via
GA44 and GA19.
GA20 can be converted to
GA1 by GA 3-oxidase. GA12,
GA53, GA20, and
GA1 can be deactivated by 2β-hydroxylation to
GA110, GA97,
GA29, and GA8,
respectively.