Rothamsted Research, Harpenden, UK.
Biochem J. 2012 May 15;444(1):11-25. doi: 10.1042/BJ20120245.
The GAs (gibberellins) comprise a large group of diterpenoid carboxylic acids that are ubiquitous in higher plants, in which certain members function as endogenous growth regulators, promoting organ expansion and developmental changes. These compounds are also produced by some species of lower plants, fungi and bacteria, although, in contrast to higher plants, the function of GAs in these organisms has only recently been investigated and is still unclear. In higher plants, GAs are synthesized by the action of terpene cyclases, cytochrome P450 mono-oxygenases and 2-oxoglutarate-dependent dioxygenases localized, respectively, in plastids, the endomembrane system and the cytosol. The concentration of biologically active GAs at their sites of action is tightly regulated and is moderated by numerous developmental and environmental cues. Recent research has focused on regulatory mechanisms, acting primarily on expression of the genes that encode the dioxygenases involved in biosynthesis and deactivation. The present review discusses the current state of knowledge on GA metabolism with particular emphasis on regulation, including the complex mechanisms for the maintenance of GA homoeostasis.
GA（赤霉素）是一类广泛存在于高等植物中的二萜羧酸，某些成员作为内源性生长调节剂，促进器官扩张和发育变化。这些化合物也由一些低等植物、真菌和细菌产生，尽管与高等植物相比，GA 在这些生物中的功能最近才被研究，目前仍不清楚。在高等植物中，GA 是由萜烯环化酶、细胞色素 P450 单加氧酶和 2-氧戊二酸依赖性双加氧酶作用合成的，分别位于质体、内质网系统和细胞质中。在其作用部位，具有生物活性的 GA 的浓度受到严格调控，并受到许多发育和环境信号的调节。最近的研究集中在调节机制上，主要作用于参与生物合成和失活的双加氧酶编码基因的表达。本综述讨论了 GA 代谢的最新知识状况，特别强调了调节，包括维持 GA 同型平衡的复杂机制。
