Abstract
In higher plants, various Z,E-mixed polyisoprenoids, including dolichol and polyprenol, are biosynthesized, showing two different distribution patterns in the chain length, C50-60 and C70-120. To understand the physiological functions of Z,E-mixed polyisoprenoids in higher plants, we analyzed abiotic stress response of cis-prenyltransferases (CPTs), which catalyze formation of the structural backbone of Z,E-mixed polyisoprenoids, in Arabidopsis thaliana.
We investigated the expression pattern of nine A. thaliana CPT (AtCPT) genes in response to various abiotic stesses by RT-PCR. AtCPT5 was induced in response to cold treatment, and both AtCPT8 and AtCPT9 were induced in response to high-salinity. AtCPT8 and AtCPT9 expressed in yeast have been shown to catalyze the formation of C80-100 polyprenyl products in vitro. In contrast, AtCPT5 expressed in Escherichia coli showed novel CPT activity, catalyzing the formation of shorter C30-35 polyprenyl products. These results suggest the involvement of AtCPT5 and its products in cold stress response in higher plant.
