Catalyzes the 2-beta-hydroxylation of several biologically active gibberellins, leading to the homeostatic regulation of their endogenous level. Catabolism of gibberellins (GAs) plays a central role in plant development. Converts GA9/GA20 to GA51/GA29 and GA4/GA1 to GA34/GA8. 2-oxoglutarate + gibberellin A1 + O2 = CO2 + gibberellin A8 + succinate Plant hormone biosynthesis; gibberellin biosynthesis. Predominantly expressed in roots, flowers, young fruits and seeds. Plants display to the slender phenotype, characterized by large amounts of GA20 that cannot be degraded, and is metabolized to excess GA1 on germination, producing plants with a characteristic slender or hyperelongated phenotype. Belongs to the iron/ascorbate-dependent oxidoreductase family. GA2OX subfamily.