Title: Gibberellins
Additional Names: GAs
Literature References: A class of plant growth hormones first isolated in 1938 from cultures of Gibberella fujikuroi (Sawada) Wollenweber (Fusarium moniliforme Sheldon) the fungus causing Bakanae disease in rice: Yabuta, Sumiki, J. Agric. Chem. Soc. Jpn. 14, 1526 (1938). Isolated also from higher plants; for source references see review by Lang, Annu. Rev. Plant Physiol. 21, 537 (1970). More than 60 gibberellins are known of which gibberellin A3, q.v., is the most important. GA3 and mixtures of GA4 and GA7 are available commercially. All gibberellins are diterpenoid acids based on the gibberellane skeleton containing the gibbane nucleus. Major structural differences lie in the substituents at positions 4a, 7, 8 (gibbane numbering) and the presence or absence of a g-lactone ring. Total synthesis of racemic gibberellins A2, A4, A9, A10: Mori et al., Tetrahedron 25, 1293 (1969); of gibberellin A4: A. L. Cossey et al., Tetrahedron Lett. 1980, 4383; of gibberellin A15: Nagata et al., J. Am. Chem. Soc. 93, 5740 (1971); of gibberellins A15 and A37: E. Fujita et al., J. Chem. Soc. Perkin Trans. 1 1977, 611. Stereochemistry: Meguro, Fuzimura, Tetrahedron Lett. 1968, 6305. Biosynthesis: Cross et al., J. Chem. Soc. C 1968, 1054; Shechter, West, J. Biol. Chem. 244, 3200 (1969). Nomenclature: MacMillan, Takahasni, Nature 217, 170 (1968). Early reviews: Brian et al., Fortschr. Chem. Org. Naturst. 18, 350 (1960); Paleg, Annu. Rev. Plant Physiol. 16, 291 (1965). Recent reviews: Cleland in The Physiology of Plant Growth and Development, M. B. Wilkins, Ed. (McGraw-Hill, New York, 1969) pp 49-81; L. Rappaport, "Applications of Gibberellins in Agriculture", in Plant Growth Subst., Proc. 10th Int. Conf., F. K. Skoog, Ed. (Springer-Verlag, Berlin, 1980) pp 377-391; I. D. Railton, Cell Biol. Int. Rep. 6, 319-337 (1982). Comprehensive synthetic review: E. Fujita, M. Node, Heterocycles 7, 709 (1977).
Use: Plant growth hormone. For specific agricultural uses see review by Turner, Outlook Agric. 7, 14 (1972).
Gibbs Reagent Gigantine Ginkgo Ginkgolides Giractide

Gibberellins (GAs) are plant hormones that regulate growth and influence various developmental processes, including stem elongation, germination, dormancy, flowering, sex expression, enzyme induction, and leaf and fruit senescence.[1]

Gibberellin was first recognized in 1926 by a Japanese scientist, Eiichi Kurosawa, studying bakanae, the "foolish seedling" disease in rice.[1][2] It was first isolated in 1935 by Teijiro Yabuta and Sumuki, from fungal strains (Gibberella fujikuroi) provided by Kurosawa.[1] Yabuta named the isolate as gibberellin.[1]

Interest in gibberellins outside of Japan began after World War II. In the United States, the first research was undertaken by a unit at Camp Detrick in Maryland, via studying seedlings of the bean Vicia faba.[1] In the United Kingdom, work on isolating new types of gibberellin was undertaken at Imperial Chemical Industries.[1] Interest in gibberellins spread around the world as the potential for its use on various commercially important plants became more obvious. For example, research that started at the University of California, Davis in the mid-1960s led to its commercial use on Thompson seedless table grapes throughout California by 1962.[3] A known antagonist to gibberellin is paclobutrazol (PBZ), which in turn inhibits growth and induces early fruitset as well as seedset.