A NOVEL TOMATO GENE THAT RAPIDLY RESPONDS TO WOUND-RELATED AND PATHOGEN-RELATED SIGNALS

The expression of a novel defence-related gene from tomato which respo nds rapidly to wound- and pathogen-related signals has been characteri sed. The gene, which encodes a protein with homology to glucosyl trans ferase enzymes, is expressed within 15 min of mechanical damage to tom ato leaves, and responds to signals which differ from those on the sys temin/jasmonic acid pathway typical of well-characterised wound-induce d genes of tomato. Furthermore, expression of the gene is also rapidly and specifically induced during a resistance response elicited by the application of Avr9 avirulence peptide to tomato plants carrying the corresponding Cf9 resistance gene. Whilst expression can also be induc ed by the application of exogenous salicylic acid and related analogue s to tomato plants, several lines of evidence suggest that elevated sa licylic acid is not a causal signal in planta during either the wound or pathogen resistance response.