The use of genetics to dissect plant secondary pathways.

Plant secondary metabolism comprises an enormous diversity in compounds and enzymes, and wide spectra of mechanisms of gene regulation and of transport of metabolites and enzymes. Genetic approaches using the model plant Arabidopsis thaliana have contributed importantly to recent progress in understanding glucosinolate biosynthesis and its intricate linkage with auxin homeostasis. Arabidopsis genetics have also caused revolutionary changes in the existing views on the metabolic intermediates and enzyme activities that are involved in phenylpropanoid biosynthesis. Some progress has been achieved in understanding the transcriptional regulation of the flavonoid pathway. Transcriptional regulators have also been identified for glucosinolate and terpenoid indole alkaloid biosynthesis.