MOLECULAR-CLONING AND THE NUCLEOTIDE-SEQUENCES OF 2 NOVEL CDNAS THAT ENCODE ANIONIC PEROXIDASES OF POPULUS-KITAKAMIENSIS

We have cloned and characterized two novel cDNAs for peroxidases from a cDNA library constructed with mRNAs from the young stem tissue of hy brid aspen, Populus kitakamiensis. Comparison of the deduced amino aci d sequences of the two cDNAs, designated pA2 and pA3, with those encod ed by other known genes for peroxidases revealed several already ident ified regions of homology (the regions of the two His residues, the di stal and proximal His residues that are bound to protoheme). Southern blot analyses indicate that pA2 and pA3 correspond to two or three gen es in each class of isoenzymes. The respective transcripts of the pA2 and pA3 groups were detected by use of gene class-specific probes and it was revealed that transcripts of both groups were expressed in the lignifying tissue of P. kitakamiensis.