DNA barcoding takes off

DNA barcoding is based on a gamble (or maybe a shrewd guess), and perhaps a smidgin of circular thinking: that there is a chunk of genome short enough to sequence quickly and cheaply, and which shows just enough variability for the entire sequence to be the same for all members of a species, but different for different species. Well, the gamble seems to have paid off. A suitable bit of a gene has duly been identified for both animals and plants, data are being ammassed, and there’s talk of a portable gadget being available in a few years which will read off the relevant sequence from a bit of leaf or skin or something and compare it with a database to give you the species name right there in the field.

Continue reading “DNA barcoding takes off”

Vitamin C mystery solved, again

I blogged three months ago now about what was touted at the time as the final elucidation of the metabolic pathway by which plants make vitamin C. The piece in EurekAlert! which I quoted says:

UCLA and Dartmouth scientists have identified a crucial enzyme in plant vitamin C synthesis, which could lead to enhanced crops. The discovery now makes clear the entire 10-step process by which plants convert glucose into vitamin C, an important antioxidant in nature… It was not until 1998 that a biosynthetic pathway was proposed to explain how plants make this compound. Research confirmed much of the pathway, although one crucial missing link continued to baffle scientists and remained unknown until this new research.

So imagine my surprise when I read this today in FreshPlaza:

Agricultural scientists say they have uncovered the last big secret of vitamin C in plants, and it will create the chance to naturally breed healthier fruits. The breakthrough in understanding just how plants manufacture vitamin C will enable state science company Hortresearch to identify DNA markers for individual plants naturally producing high levels of the vitamin… Hortresearch’s science general manager, Dr Bruce Campbell said the team had isolated the last undiscovered enzyme and proved it controlled vitamin C in plants. The enzyme was the last step in a chain of research begun overseas nearly 80 years ago by scientist seeking to understand how plants produce vitamin C.

The research comes from New Zealand rather than the US, and was carried out on wild and cultivated kiwi fruit species with contrasting levels of vitamin C, rather than on Arabidopsis, but otherwise sounds as if it was aimed at solving pretty much the same problem. No way to tell from these brief summaries of the two pieces of work whether they came up with the same answer, though. That will take some more digging.

Anyway, it does seem likely that gene-jockeys will be falling over themselves all too soon trying to engineer a higher vitamin C apple, marula or whatever. Good luck to them. I’m no Luddite. But our friend Ola does have a point in his comment on my recent post on potatoes. Would it not maybe be easier and more cost effective to try to get people to eat foods which are naturally high in vitamin C?

Genotyping Support Service

The CGIAR’s Generation Challenge Programme‘s mission is

To use advanced genomics science and plant genetic diversity to overcome complex agricultural bottlenecks that condemn millions of the world’s neediest people to a future of poverty and hunger

They’ve just announced a new service: the Genotyping Support Service. What will GSS do?

Here’s a sample of what our latest service offers: assessing proposals, hiring genotyping services from the best providers, taking care of the administrative hassles, ensuring the generation of high-quality data and training participating researchers to interpret and work with the data to optimise outputs. In this way, researchers get to use the technology right away, while also learning how to get the greatest mileage out of the technology, thus creating local capacity. As such, GSS contributes to GCP’s effort to support and motivate plant breeding ‘champions’ in developing regions.