Combining Genomics and Metabolomics for the Discovery of Regulatory Genes and Their Use in Metabolic Engineering to Produce 'Healthy Foods'

Abstract

Plants often accumulate their natural products to relatively low levels, so there is a lot of interest in breeding or engineering plants that produce higher levels. It has been shown that the most effective way to increase the accumulation of secondary metabolites is to increase the activity of genes that regulate the activity of the biosynthetic pathways that make different natural products. Regulatory genes of this type encode proteins called transcription factors. The biggest bottleneck in using this strategy to develop plants that accumulate significantly higher levels of important natural products is that not many transcription factors regulating secondary metabolism have yet been identified at the molecular level. Genes encoding transcription factors can be identified from model plants with sequenced genomes. The ability of such genes to regulate metabolism can be assayed by examination of mutants (reverse genetics) and by investigating the metabolic effects of high levels of expression of the genes. The combined techniques of metabolic fingerprinting and metabolite profiling of mutant and transgenic plants are allowing us to identify new genes encoding transcription factors controlling secondary metabolism, that can be used as tools for engineering natural product accumulation.

Genetic engineering of grass cell wall polysaccharides for biorefining

“…Such phenotypic effects can either be a direct result of TF‐induced changes in cell wall composition or due to pleiotropic effects as a cell wall‐associated TF may also be involved in the regulation of developmental processes or in the response to biotic and abiotic stresses (Fornalé et al ., ; Zhong et al ., ). Overexpression studies can also lead to metabolic spillover into related pathways, and TFs may lose some target specificity when expressed at high levels (Martin et al ., ). Such off‐target effects may make TFs perhaps less tractable and more challenging as tools for grass cell wall engineering.…”