Peanut (Arachis hypogea L.) peroxidase gene expression was analyzed by measuring the accumulation of trancripts in cultured cells and various plant parts (leaf, stem, root) and upon their treatment with ethylene or wounding, respectively. Two transcripts (prxPNC1 and prxPNC2) corresponding to two peroxidase genes are expressed at higher levels in cultured cells as compared to various plant organs. Analysis of total poly(A)(+) RNA with an oligonucleotide probe corresponding to a highly conserved region of peroxidase genes showed the expression of three peroxidase related sequences (1,000, 1,400 or 2,600 bp) in stem or leaf but barely detectable in roots. The prxPNC2 transcript transiently expressed at high levels in response to ethylene treatment of cells or wounding of leaves. This suggests that the corresponding gene(s) are expressed in response to stress.