METHODS OF REGENERATION AND TRANSFORMATION OF STEVIA PLANT AND TRANSGENIC STEVIA PLANTS HAVING ENHANCED STEVIOL GLYCOSIDES CONTENT

摘要

The present invention relates to a method for Agrobacterium-mediated transformation and regeneration of Stevia plants. In particular, the method involves co-culturing leaf explants with Agrobacterium in a medium comprising acetosyringone and 2,4-dichlorophenoxyacetic acid in the dark, callus induction and shoot regeneration in a medium comprising 6-benzylaminopurine, 3-indoleacetic acid, a selective agent and an Agrobacterium eradicant in the dark, and root regeneration in a medium comprising 3-in-doleacetic acid in a light/dark cycle. The present invention also relates to the overexpression of SrDXS I and SrKAH in transgenic plants, resulting in the enhancement of steviol glycosides in the transgenic plants. The present invention further relates to the overexpression SrUGT76G I in transgenic plants, resulting in higher Rebaudioside A (Reb A) to stevioside ratios in the transgenic plants.