Gibberellin-Mediated Regulation of Vegetative Growth and Flowering of Hydroponics-Grown Tea Trees

Abstract

Gibberellin(GA) regulates shoot and root growth and flowering of many plants. Since the physiological function of GA in the growth and development of tea trees, particularly in roots, is not well known, we studied the morphological and growth-enhancing effects of GA in combination with the inhibitor of GA-biosynthesis to decrease the endogenous GA level. Root-applied GA3 strongly promoted shoot growth but little affected root elongation itself. However, the inhibitor of GA-biosynthesis promoted flower bud formation and inhibited shoot and root elongation with remarkable thickening of root apices. These inhibitor effects were completely reversed by GA3. The possibility was presented that the shoot and root growth, and flower initiation are controlled by restraining the GA level of tea plants and the method may contribute the efficient production and propagation of tea trees.