Abstract
Many temperate plants, such as temperate grasses, synthesize fructan that is considered to play an important role in the response to environmental stresses as an osmoregulation factor. Perennial ryegrass is one of the most important temperate grasses. Perennial ryegrass, however, is sensitive to environmental stresses in comparison with other temperate grasses. To improve cold tolerance of perennial ryegrass, we have made transgenic plants carrying wft1 and wft21), which encode wheat sucrose-fructan 6-fructosyltransferase and sucrose-sucrose 1-fructosyltransferase, respectively.
Of 16 transgenic plants analyzed, two plants containing wft1 and three plants containing wft2 showed significant increase in fructan accumulation compared with non-transgenic plants. Freezing tolerance of transgenic plants were tested by electrical conductivity method. Some transgenic plants were more tolerant to cold stress than non-transgenic plants, suggesting that an increase in fructan accumulation might be effective in enhancing cold tolerance in perennial ryegrass.
1)Kawakami and Yoshida, Biosci, Biotechnol. Biochem. 66, 2297-2305 (2002)
