Abstract
In higher plants, various Z,E-mixed polyisoprenoids, including dolichol and polyprenols, are biosynthesized. However, their physiological function in higher plants is hardly elucidated. In our previous studies, an Arabidopsis thaliana cis-prenyltransferase AtCPT5, which biosynthesizes medium-chain Z,E-mixed polyisoprenoid (C30-35), was shown to be induced by the cold stress and the ABA treatment, suggesting the involvement of AtCPT5 in the response to abiotic stresses. In this presentation, we report on the physiological characterization of a T-DNA insertion mutant of AtCPT5 under various abiotic stresses, such as low temperature, high salinity, high osmolality, and the ABA treatment. atcpt5 showed a suppression of lateral root emergence under normal growth conditions. Although tolerance of atcpt5 to the abiotic stresses was comparable to that of WT, atcpt5 showed some ABA hypersensitive phenotypes in suppression of germination, primary root elongation, and lateral root emergence, indicating the involvement of AtCPT5 in the ABA-mediated root morphogenesis.
