Characterisation of a wound-induced transcript from the monocot asparagus that shares similarity with a class of intracellular pathogenesis-related (PR) proteins

We report the isolation and characterisation of a wound-induced cDNA designated AoPR1 from a suspension of mesophyll cells that had been mechanically isolated from cladodes of light-grown Asparagus officinalis seedlings by grinding in a mortar and pestle. The transcript abundance is up-regulated following cell separation and in chopped mesocotyl tissue from dark-grown seedlings. The expression of AoPR1 was shown by northern analysis to be located around the site of damage. Sequence analysis revealed similarity between the predicted AoPR1 polypeptide and bean PvPR1 and PvPR2 proteins, the potato pSTH2 protein, the pea PI49 protein, the parsley PcPR1-1 protein and a major pollen allergen from birch (BetvI). These transcripts have been shown to be induced in response to microbial attack or fungal elicitation. To our knowledge, this is the first example of a monocot cDNA belonging to this class of intracellular pathogenesis-related proteins (IPRs).