Molecular cloning and partial characterization of a tobacco cDNA encoding a small bZIP protein.

Here we report the isolation of a tobacco cDNA which is a counterpart gene of rice low-temperature-induced lip19. Expression of the gene (termed tbz17) is also positively controlled by low temperature but fairly moderately compared with the low-temperature-responsiveness of rice lip19 and the maize counterpart gene, mlip15. The predicted gene product (termed TBZ17) is a bZIP protein of 145 amino acids and shows about 45% identity with rice LIP19 and maize mLIP15 proteins. DNA binding studies indicate that TBZ17 has quite similar DNA binding characteristics to that of mLIP15. The results suggest that low-temperature-induced gene(s) encoding a DNA binding factor with bZIP motif is omni-present in higher plants.