Molecular Cloning and the Nucleotide Sequences of Two 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 hybrid aspen, Populus kitakamiensis. Comparison of the deduced amino acid sequences of the two cDNAs, designated pA2 and pA3, with those encoded by other known genes for peroxidases revealed several already identified regions of homology (the regions of the two His residues, the distal and proximal His residues that are bound to protoheme). Southern blot analyses indicate that pA2 and pA3 correspond to two or three genes 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