Catalyzes the 2-beta-hydroxylation of gibberellins (GA) precursors, rendering them unable to be converted to active GAs. Hydroxylates the C20-GA GA12 and GA53, but is not active on C19-GAs, like GA1, GA4, GA9 and GA20. 2-oxoglutarate + gibberellin A1 + O2 = CO2 + gibberellin A8 + succinate Binds 1 Fe(2+) ion per subunit. Plant hormone biosynthesis; gibberellin biosynthesis. A number of isoforms are produced. According to EST sequences. Up-regulated by auxin. Down-regulated by paclobutrazol. Belongs to the iron/ascorbate-dependent oxidoreductase family. GA2OX subfamily. Extended C-terminus.