Overexpression of () Induces Dwarfism and Smaller Leaves, Flowers and Fruits in and .

Gibberellins (GAs) are plant hormones that play fundamental roles in plant growth and development. Gibberellin 2-oxidase (GA2ox) plays a direct role in determining the levels of bioactive GAs by catalyzing bioactive GAs or their immediate precursors to inactive forms. In this study, a gene, designated , was isolated from . is expressed in all tissues of adult , with the highest expression level in male flowers and the lowest expression level in young leaves. Overexpression of in resulted in a typical dwarf phenotype, along with late flowering, smaller leaves and flowers, shorter siliques and smaller seeds. Similarly, when was overexpressed in , the transgenic plants exhibited a dwarf phenotype with dark-green leaves and smaller inflorescences, flowers, fruits and seeds. However, the flowering time of was not affected by overexpression of , unlike that in the transgenic . Moreover, the number of flowers per inflorescence, the weight of 10 seeds and the seed oil content were significantly decreased in transgenic . The results indicated that overexpression of had a great impact on the vegetative and reproductive growth of transgenic . Furthermore, we found that the dwarf phenotype of transgenic was caused by a decrease in endogenous bioactive GA, which was correlated with the degree of dwarfism.