Gibberellins - Plant Growth Substances

In late 1920's Kurosawa observed that the medium in which the fungus Gibberella had grown could cause the abnormal tallness in rice seedlings. This work was later taken up by Yabuta and Sumiki (1938) who isolated a crystalline product from Gibberella and named it Gibberellin. Later, Gibberellins were isolated from bean plants by MacMillan, and from citrus plants by Sumiki, from Bamboo shoots by Takahashi and Tamura. This established the wide occurrence of Gibberellins in plants. Today, we know that more than 70 different Gibberellins exist. All have a common skelton but variations are caused by substitutions at several positions in the molecule.