gibbereliny

Gibberellins are a class of plant hormones that play a crucial role in regulating growth and development across various plant species. First discovered in 1938 during research on the "foolish seedling" disease in rice, which caused abnormal elongation of stems, gibberellins were later isolated and identified as the causative agents. The name "gibberellin" originates from the Japanese term *gibberella*, referring to the fungus *Gibberella fujikuroi*, which produces these hormones in excess, leading to the disease symptoms.

Gibberellins are involved in multiple physiological processes, including stem elongation, germination, flowering, fruit development, and leaf and flower senescence. They promote cell division and expansion, particularly in stems, leading to increased plant height. In seeds, gibberellins trigger the breakdown of storage compounds like starch into sugars, facilitating germination. They also influence flowering by breaking dormancy in some plants and promoting the formation of flowers in others. Additionally, gibberellins play a role in fruit growth, particularly in parthenocarpy—the development of fruit without fertilization—and in the abscission of leaves and flowers.

These hormones are synthesized in various parts of the plant, including young leaves, roots, and developing seeds, and are transported through the phloem to target tissues. Their effects are often modulated by other hormones, such as auxins and abscisic acid, creating complex interactions that regulate plant growth. Gibberellins are commercially produced and used in agriculture to enhance germination, promote flowering, and improve fruit set in crops. Synthetic gibberellins, such as gibberellic acid (GA₃), are widely applied in horticulture to achieve desired growth responses.