gibberelliin

Gibberellins are a class of plant hormones that play a crucial role in various growth and developmental processes. They are a group of approximately 126 identified compounds, though only a subset of these are biologically active in plants. These hormones are primarily produced in young leaves and developing seeds.

The primary functions of gibberellins include promoting stem elongation, breaking seed dormancy, and initiating germination. They achieve stem elongation by stimulating cell division and cell expansion in the internodes of plants. This effect is particularly important for plants that grow tall and slender. In seeds, gibberellins act by counteracting the effects of abscisic acid, another plant hormone, thereby promoting germination. They also influence the development of flowers and fruits, often leading to larger fruits and the induction of flowering in certain species.

Gibberellins were first discovered in Japan in the 1930s when researchers observed that a fungus, Gibberella fujikuroi, caused abnormal elongation in rice seedlings. Further research identified the active compounds produced by this fungus, which were subsequently named gibberellins. Today, gibberellins are widely used in agriculture and horticulture to improve crop yields and quality. They are applied to stimulate fruit growth, increase the size of grapes, and promote earlier flowering in ornamental plants.