Improvement of freezing tolerance in tobacco plants expressing a cold-responsive and chloroplast-targeting protein WCOR15 of wheat

• Published in: Journal of plant physiology 2006-02, Vol.163 (2), p.213-219
• Main Authors: Shimamura, Chisa, Ohno, Ryoko, Nakamura, Chiharu, Takumi, Shigeo
• Format: Article
• Language: English
• Subjects: Adaptation to environment and cultivation conditions; Adaptation, Physiological; Agronomy. Soil science and plant productions; Biological and medical sciences; Chloroplast; Chloroplasts; cold tolerance; Cold-responsive gene; Freezing; Freezing tolerance; Fundamental and applied biological sciences. Psychology; gene expression regulation; Gene Expression Regulation, Plant - physiology; Gene Targeting; Genetics and breeding of economic plants; Green fluorescence protein; late embryogenesis abundant protein; Nicotiana; Nicotiana - genetics; Nicotiana - physiology; Nicotiana tabacum; plant biochemistry; plant physiology; plant proteins; plant response; Plants, Genetically Modified; promoter regions; Recombinant Fusion Proteins - biosynthesis; tobacco; transgenes; transgenic plants; Triticum - genetics; Triticum aestivum; Varietal selection. Specialized plant breeding, plant breeding aims; wheat; Wheat ( Triticum aestivum)
• ISSN: 0176-1617; 1618-1328
• DOI: 10.1016/j.jplph.2005.06.008

Cold acclimation, an adaptive process for developing freezing tolerance in over-wintering plants, is associated with increased expression levels of a series of cold-responsive ( Cor)/late embryogenesis abundant ( Lea) genes. To investigate the function of Wcor15, a member of the wheat Cor/Lea gene family, for improvement of freezing tolerance, two types of transgenic tobacco lines expressing Wcor15-containing chimeric genes were produced and characterized. Immunoblot and gene expression analyses of a transgenic tobacco line expressing the Wcor15-GFP fusion gene under control of the CaMV35S promoter showed transport and abundant accumulation of the WCOR15 protein in the stromal compartment of the chloroplasts. The 5′ upstream region of Wcor15 induced expression of the GFP reporter gene under low-temperature conditions in the transgenic tobacco. Both transgenic lines expressing the Wcor15-GFP fusion gene showed a similar and significantly improved level of freezing tolerance compared with the wild-type tobacco plants. Our results demonstrate that the induced expression of the wheat Wcor15 gene positively contributes to the development of freezing tolerance in the heterologous tobacco plants.