Plant response to mechanical injury includes gene activation both at the
wound site and systemically in nondamaged tissues. The model developed for the
wound-induced activation of the
proteinase inhibitor II (Pin2) gene in potato (Solanum tuberosum) and tomato (Lycopersicon esculentum) establishes the involvement of the
plant hormones abscisic acid and
jasmonic acid (JA) as key components of the
wound signal transduction pathway. To assess in Arabidopsis thaliana the role of these
plant hormones in regulating
wound-induced gene expression, we isolated
wound- and JA-inducible genes by the differential
mRNA display technique. Their patterns of expression upon mechanical wounding and hormonal treatments revealed differences in the spatial distribution of the transcripts and in the responsiveness of the analyzed genes to
abscisic acid and JA. A correlation can be established between sensitivity to JA and the accumulation of the transcripts in systemic tissues upon wounding. A comparative study of the
wound response in wild-type and JA-insensitive coi1 mutant plants indicated that in A. thaliana
wound signals are transmitted via at least two different pathways. One of them does not involve JA as a mediator and is preferentially responsible for gene activation in the vicinity of the
wound site, whereas the other requires JA perception and activates gene expression throughout the aerial part of the plant.