Since colonising land,plants have undergone massive metabolic diversification.This is reflected by the numbers of metabolites that they collectively produce (estimated to be 105 to 106) [1,2];also,by our increasing awareness of the thousands of uncharacterised genes within plant genomes with predicted roles in specialised metabolism (approximately 20%) [3].The ~200,000 plant metabo-lites that have been reported thus far from nature [4] are likely to represent just the tip of the iceberg.An enormous amount of meta-bolic "dark matter" encoded within the DNA instruction manual of the plant kingdom therefore remains to be discovered.