Gibberellins (GAs) are tetracyclic diterpenoid phytohormones that have diverse biological roles in plant growth and development, such as stem elongation, seed germination, floral induction and anther development in seed plant. Until now, more than 140 gibberellins have been identified, only a few, including GA4, GA1, GA3, and GA7, function as bioactive gibberellins. These bioactive gibberellins have structural common features, that is, a carboxyl group at the C6 position (C6-COOH), a hydroxyl group at the C3 position (C3-OH) of the ent-gibberellane skeleton, a γ-lactone ring, and a non-hydroxyl group at the C2 position (C2-non OH). Gibberellins are perceived and transduced for their specific responses through GID1 (receptor)-GA-DELLA (repressor) system. Both biosynthesis and the signaling of gibberellin were established in fern, and finetuned in gymnosperm and angiosperm, including the establishment of their inactivation systems. Here, I reviewed the co-evolution of synthesis/inactivation and signal transduction of gibberellin, especially in the structural aspects.
