CBF3/D REB1A Transgenic Lines Of Tall Fescue With Drought-resistance

Tall fescue(Festuca arundinacea Schreb), with higher resistance to stress and stronger adaptive ability, was planted worldwide, either for forage or for turf-type grass. It is spreads rapidly in China in recent years. Some obvious defects such as less salt or drought tolerance restricted the spreadness of tall fescue.Traditional breeding is time-consuming and laborious, and there is a lack of background knowledge of inheritance. Greatly developed molecular biology techniques help us to clone more and more stress related genes. Based on the further comprehension of their expression and function, great passion has being given to breed tall fescue with high salt-tolerance and dry-tolerance by genetic engineering.Since Paz-Ares et al first reported that they had cloned transcription factor from maize in 1987, thousands of transcription factors has been found. They play important roles in the regulation of plant growth and development, as well as in resisitance to environmental stresses. Transcription factors interact with cis-elements and regulate the expression of target genes.More and more research proved that it's difficult to improve growth, yield and tolerance to environmental stresses of plants by transferring single functional gene. For example, overexpression of COR15a has a detectable effect on freezing tolerance of chloroplasts and protoplasts, the effect is small (Artus et al., 1996; Steponkus et al., 1998). Moreover, it has little if any effect on whole-plant freezing survival. Expression of the entire battery of COR genes, which includes the COR6.6, COR47, and COR78 gene pairs (in addition to the COR15 gene pair), however, does (Jaglo-Ottosen et al., 1998).Recent efforts have defined a cis-acting DNA regulatory element in plants, the C-repeat/dehydration responsive element (DRE), that stimulates transcription in response to low temperature and water deficit. DRE/CRE core element is present in one to multiple copies in the promoters of many abiotic tolerance regulated plant genes, including the genes of cold, salt and drought etc.