Gibberellin phytohormone metabolism

Abstract

Gibberellin (GA) phytohormones are potent and complex diterpenoids biosynthesized by a phylogenetically diverse group of organisms. Originally discovered in the phytopathogen Fusarium fujikuroi, it is now appreciated that analogous metabolism exists in plants, fungi, and bacteria. Intriguingly, each of these broad groups of organisms appears to have independently evolved biosynthetic pathways leading to the production of these complex natural products. Our current understanding of the diverse GA metabolism in each group is presented here, with an emphasis on the characteristics, particularly relevant enzymatic type, that differentiate their GA biosynthetic pathways from each other. Furthermore, in plants GA biosynthesis shares steps in common with other isoprenoid and related diterpenoid natural products, and an overview is provided of the necessary metabolic integration as well as various catabolic process involved in breaking down bioactive GAs in planta.