<Tr> <Td_colspan="2"> Infobox references </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> </Tr> <P> Gibberellins (GAs) are plant hormones that regulate various developmental processes, including stem elongation, germination, dormancy, flowering, flower development and leaf and fruit senescence . GAs are one of the longest - known classes of plant hormone . It is thought that the (albeit unconscious) selective breeding of crop strains that were deficient in GA synthesis was one of the key drivers of the "green revolution" in the 1960's, a revolution that is credited to have saved over a billion lives worldwide . </P> <P> The first inroads into the understanding of GAs were developments from the plant pathology field, with studies on the bakanae, or "foolish seedling" disease in rice . Foolish seedling disease causes a strong elongation of rice stems and leaves and eventually causes them to topple over . In 1926, Japanese scientist Eiichi Kurosawa identified that foolish seedling disease was caused by the fungus Gibberella fujikuroi . Later work at the University of Tokyo (notable from Yabuta, Sumiki and Hayashi) showed that a substance produced by this fungus triggered the symptoms of foolish seedling disease and they named this substance "gibberellin". </P>

What is the role of gibberellins in plants