James and the Giant Corn Genetics: Studying the Source Code of Nature

One controversy I seem to have completely missed out during my break was the protests over seed donations to Haiti this summer.

Yup, I said protests over donated seeds.

Well, (you might think): if these people are honestly convinced genetically engineered crops are dangerous (and clearly there are people in the world who really believe that) you can see how they’d react badly to feeling like they were be offered something that could harm their health, even (or perhaps especially) if it was being given freely as a gift.

Unfortunately even that rationalization isn’t any use here, since none of the donated seeds were genetically modified, as (almost) all the coverage eventually gets around to mentioning.

As far as I can tell at this late date the reasons people are upset boil down to three issues: (more…)

Photo Rainer Ebert, Flickr (click to view in original context)

The rice of my childhood was brown rice, incompletely stripped of its outer coating to retain more vitamins and minerals. Frankly it wasn’t very appetizing, and it was a pleasant surprise to discover rice can actually be delicious when it’s not also trying to be a health food. Never the less I consider myself to be a relatively unsophisticated rice-eater. If my rice is a different color I’ll probably notice, but a lot of the more subtle variations between different breeds slip by without grabbing my attention. (more…)

What an clever rule of thumb!

Domestication, then, seems to be associated with changes in transcriptional regulatory networks, whereas crop diversification involves a larger proportion of enzyme-encoding loci.

In other words, when it comes to transforming a wild plant species into one that is adapted to being grown by humans for food, in other words, changing the shape or function of the plant itself, you’ll usually want to mess around with the regulation of transcription factors (the genes that regulate how other genes are expressed), but when it comes to selecting for the qualities of the food itself (for example: different tastes, colors, smells, or nutritional values) it makes more sense to mess around with the genes that are directly involved in changing one kind of molecule into another. I wonder how generalizable that is?

Some examples from the paper:

• Having seeds stick to the plant so they’re easier to harvest? Transcription factors <– To understand how important a trait this is, imagine trying to harvest a field full of ripe dandelion flowers… one good breeze and your whole crop is lost.
• Growing as a single stalk? Transcription factors
• Seeds that are no longer encased in hard protective cases? Transcription factors
• Sticky rice and sticky varieties of other grains? Biochemistry genes (Enzymes)
• Yellow corn*? Biochemistry genes (Enzymes)

Reading reviews like this one make me remember why it was the genetics of domestication that got me hooked on plant genetics in the first. Even if I have to go through a few intellectual contortions to tie my own research back into this field.

And completely unrelated to the subject of this post, I just want to say thank you to everyone who commented on my last entry. Has it been more than a month already?.

*Also golden rice, but that’s the result of a much more conscious form of selection.

Michael D. Purugganan and Dorian Q. Fuller, “The nature of selection during plant domestication,” Nature 457, no. 7231 (February 12, 2009): 843-848.  doi: 10.1038/nature07895