Genetic engineering of salt and drought tolerance in rice cultivars

摘要

New biotechnologiesl tools have a potential to contribute significantly to improving drought and salt tolerance in rice, We studied the enhancement of salt and drought tolerance in transgenic rice by overexpressing key genes involved in the synthesisof osmoprotectants (praline, trehalose) as well as specific transport systems to counteract the effects of osmotic stress and, more specifically, ion toxicity of salt stress. To meet this objective, a series of expression plasmids for rice transformationhas been developed, harboring these key genes under the control of a strong promoter. An efficient procedure of Agtofoacterium-mediated transformation is routinely applied to japonica varieties (Zhongzuo 321) and is being adapted for indica varieties (CR203 and DR2). In addition, optimizing the regeneration and transformation via biolistics of variety Zhongzuo 321 has been successful. All designed constructs were introduced into rice varieties via particle bombardment and Agrobacterium. The T_0 transformants produced by both methods were evaluated to allow the identification of the unique attributes of each technology and also to determine which T_1 progeny transformants were the best candidates for molecular and biochemical analyses. These T_1 transgenic plants will be fully analyzed at the molecular and biochemical levels and their stress tolerance will be evaluated in vitro and in field experiments,