But there’s a catch here. We have to help the plants a little ourselves, because what plants like to do is put most of the CO2 into sugars. And when the end of the growing season comes, the plant dies and decomposes, and then all that work they did to suck out the CO2 from the atmosphere and make carbon-based biomass is now basically going right back up in the atmosphere as CO2.
So how can we get plants to redistribute the CO2 they bring in into something that’s a little more stable?
And so it turns out that plants make this product, and it’s called suberin. This is a natural product that is in all plant roots. And suberin is really cool, because as you can see there, I hope, everywhere you see a black dot, that’s a carbon. There’s hundreds of them in this molecule.
And where you see those few red dots, those are oxygens. And oxygen is what microbes like to find so they can decompose a plant. So you can see why this is a perfect carbon storage device. And actually it can stabilize the carbon that gets fixed by the plant into something that’s a little bit better for the plant. And so, why now?
Why is now a good time to do a biological solution to this problem?
It’s because over the last 30 or so years — and I know that’s a long time, you’re saying, “Why now?” — but 30 years ago, we began to understand the functions of all the genes that are in an organism in general. And that included humans as well as plants and many other complicated eukaryotes.
And so, what did the 1980s begin? What began then is that we now know the function of many of the genes that are in a plant that tell a plant to grow. And that has now converged with the fact that we can do genomics in a faster and cheaper way than we ever did before.
And what that tells us is that all life on earth is really related, but plants are more related to each other than other organisms. And that you can take a trait that you know from one plant and put it in another plant, and you can make a prediction that it’ll do the same thing. And so that’s important as well.
Then finally, we have these little genetic tricks that came along, like you heard about this morning — things like CRISPR, that allows us to do editing and make genes be a little different from the normal state in the plant.
OK, so now we have biology on our side. I’m a biologist, so that’s why I’m proposing a solution to the climate change problem that really involves the best evolved organism on earth to do it — plants.
So how are we going to do it?
Biology comes to the rescue. Here we go. OK.
You have to remember three simple things from my talk, OK? We have to get plants to make more suberin than they normally make, because we need them to be a little better than what they are.
We have to get them to make more roots, because if we make more roots, we can make more suberin — now we have more of the cells that suberin likes to accumulate in.
And then the third thing is, we want the plants to have deeper roots. And what that does is — we’re asking the plant, actually, “OK, make stable carbon, more than you used to, and then bury it for us in the ground.” So they can do that if they make roots that go deep rather than meander around on the surface of the soil.
Those are the three traits we want to change: more suberin, more roots, and the last one, deep roots.
Then we want to combine all those traits in one plant, and we can do that easily and we will do it, and we are doing it actually, in the model plant, Arabidopsis, which allows us to do these experiments much faster than we can do in another big plant.
And when we find that we have plants where traits all add up and we can get more of them, more suberin in those plants, we’re going to move it all — we can and we will, we’re beginning to do this — move it to crop plants.
And I’ll tell you why we’re picking crop plants to do the work for us when I get to that part of my talk.
OK, so I think this is the science behind the whole thing. And so I know we can do the science, I feel pretty confident about that. And the reason is because, just in the last year, we’ve been able to find single genes that affect each of those three traits. And in several of those cases, two out of the three, we have more than one way to get there.