Definition for Gibberellin
From Biology Forums Dictionary
1) A plant hormone that stimulates both cell division and cell elongation.
2) Gibberellins (also known as gibberellic acids or GA) are terpenoid-derived hormones that are produced in apical buds, roots, young leaves, and seed embryos. Gibberellins stimulate both cell division and cell elongation, thereby fostering growth. They accomplish this by promoting the destruction of certain nuclear proteins—known as DELLA proteins—which are negative regulators of cell division and expansion. Gibberellins promote stem elongation and flowering, and they retard leaf and fruit aging. They also play roles in seed germination.