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

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-indoleacetic acid in a light/dark cycle. The present invention also relates to the overexpression of SrDXS1 and SrKAH in transgenic plants， resulting in the enhancement of steviol glycosides in the transgenic plants. The present invention further relates to the overexpression SrUGT76G1 in transgenic plants， resulting in higher Rebaudioside A (Reb A) to stevioside ratios in the transgenic plants. 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-indoleacetic acid in a light/dark cycle. The present invention also relates to the overexpression of SrDXS1 and SrKAH in transgenic plants， resulting in the enhancement of steviol glycosides in the transgenic plants. The present invention further relates to the overexpression SrUGT76G1 in transgenic plants， resulting in higher Rebaudioside A (Reb A) to stevioside ratios in the transgenic plants.