MOLECULAR-CLONING, SEQUENCE-ANALYSIS AND ELICITOR-INDUCED OZONE-INDUCED ACCUMULATION OF CINNAMYL ALCOHOL-DEHYDROGENASE FROM NORWAY SPRUCE (PICEA-ABIES L)

Cinnamyl alcohol dehydrogenase (CAD) is an enzyme involved in lignin b iosynthesis. We have previously isolated pure CAD enzyme from Norway s pruce (Picea abies L.) cell culture. Here we report on partial protein sequences of the 42 kDa CAD polypeptide. A cDNA encoding CAD was isol ated from the spruce cell culture. The open reading frame of a full-le ngth cDNA coded for a 357 amino acid polypeptide with a calculated M(r ) of 38 777 Da. The identity of the deduced polypeptide was verified b y comparison with amino acid sequences of tryptic peptides from the pu rified enzyme. Southern blot analysis showed the presence of only one gene for CAD. Sequence comparison with CAD from tobacco and with a N-t erminal protein sequence from loblolly pine CAD showed an identity of 69.7% and 91.5% respectively. Treatment of spruce cell cultures with e licitor, as well as of seedlings with ozone both markedly increased th e CAD mRNA level.