The gene-for-gene concept is central to most efforts to bioengineer plants
for disease resistance. Tn the more than 50 years since Flor first proposed
the gene-for-gene concept, it has served as an important focus for researc
h an plant disease resistance. This presentation looks briefly at the "evol
ution" of our understanding of gene-for-gene resistance in relation to the
prospects for bioengineering. The Cladosporium fulvum-tomato interaction is
used to illustrate how understanding the signal transduction pathway follo
wing interactions between the pathogen elicitor and a putative receptor may
lead to new approaches to bioengineering disease resistant cultivars. Tn t
his context, recent data are reviewed, confirming that the oxidative burst
seen in the defense response of tomato to C.fulvum has strong similarity to
that of mammalian phagocytic neutrophil cells.