salinity tolerance in cereals

Rajendran, K., Tester, M. & Roy, S.J. (2009) Quantifying the three main components of salinity tolerance in cereals. Plant, Cell & Environment 32, 237-249

from Naked Scientist:
http://www.thenakedscientists.com/HTML/content/interviews/interview/1239/

Chris - So how did you do that rather clever trick of making that gene only get turned on in those cells around these xylem vessels because that’s the breakthrough step, isn’t it really?

Mark - Yes, it is. There’s different ways you can do this. One is to try to discover little bits of DNA which will activate genes in specific parts of the plant. So that’s one way you can do it a very direct way. In the meantime, we’re using a model plant. It’s called Arabidopsis. It’s a silly little weed, but you can do lots of really nice molecular genetics with it. And what we did was throw into the genome of this little plant, this little weed, a little bit of DNA which allows us to turn on genes. But we threw it on in random in the genome, made thousands of these plants and then looked at the plants to find ones which had the right pattern of expression. So the initial generation of the plants was random and then we looked to find plants which had by fluke, this bit of DNA landing in a part of the genome that would activate that gene only in the inner half of the root.

Chris - Big question though, Mark must be a course, it’s one thing to do this in thale cress, the plant sciences fruit fly. But we don’t eat that. So what about things that we do eat? Could you put this same genetic combination into rice, into barley, wheat, and so on? The kinds of things we do rely on for food staples.

Mark - Absolutely, Chris. We have done this in rice and the results are looking very promising. We look like we’ve worked out how to reduce the sodium concentration. Well we have reduced the sodium concentration in the shoots of rice and we’re in the process of testing the effect of that on yield. The first experiments did improve yield, but we just want to again be fairly conservative rather than just shooting off the results rapidly. But it’s looking very promising. To turn the genes on in wheat and barley, maze, it’s actually quite difficult because these molecular genetic tricks that we’re able to use on Arabidopsis, we just simply can’t do it. We’re technically not able to do it in wheat and barley. So what we’re doing now is we’re having a program to discover the promoters that would help us turn this on, so going back to a very direct but slower way of manipulating an expression in wheat and barley. We actually have transgenic plants in the glasshouse at the moment for wheat and barley and we’re limited by bulking up the seed, and we’re just at that stage at the moment. So keep your fingers crossed for us and hopefully in the year’s time, we’ll be able to say if we’ve done it in the other crops as well.