Metabolic bang-for-the-buck

DellaPenna says his team and others are still sifting through massive amounts of plant genomic data, to identify the genes involved in these metabolic pathways, and to determine how they evolved. He says plants actually have composite genomes derived from multiple endosymbiotic events during their evolution – for example, their acquisition of chloroplasts and mitochondria.

To date, his team has identified only single-gene variation influencing these metabolic pathways; it hopes to identify natural variants of transcription-factor genes that regulate entire pathways. Because transcription factors drive coordinated networks of scores to hundreds genes, they offer prospects for more metabolic bang-for-the-buck.

In terms of industrial applications, some plant groups specialise in synthesising novel compounds like morphine and other alkaloids.

“We can identify a shortlist of genes that might be involved in the synthesis pathway, then mass-spec all the compounds they produce,” he says. “We’re only scratching the surface of what is going on out there in the plant world. Much of the interesting variation has no visible effect on the phenotype of the plant – it’s only apparent at the biochemical level. As the instruments get better, we’re getting bigger telescopes that allow us to see many more things.”

The natural-variation approach relieves researchers of having to make assumptions about what is important. Mother Nature may not know what is best for humans, but she is at least telling researchers what is important, he says.