Genetic improvement of Chinese cabbage for salt and drought tolerance by constitutive expression of a B. napus LEA gene

This is the first report on transformation of Chinese cabbage with late embryogenesis abundant (LEA) gene. Transgenic Chinese cabbage (Brassica campestris ssp. pekinensis) expressing a B. napus late embryogenesis abundant protein gene had been generated. Infection by Agrobacterium strain LBA4404 containing the binary vector pIG121-LEA, which carried LEA protein gene linking to CaMV promoter and terminator sequences, and the neomycin phosphotransferase II (NPTII) gene, was applied. Generated shoots were selected by their growth ability on revised MS medium containing kanamycin sulphate. Transgenic Chinese cabbage plants demonstrated enhanced growth ability under salt- and drought-stress conditions. The increased tolerance was reflected by delayed development of damage symptoms caused by stress. The increased tolerance also showed improved recovery upon the removal of stress condition. These results suggest that the genetic modification of Chinese cabbage by LEA protein gene holds considerable potentiality for crop improvement toward environment-stress tolerance.