My name is Johanna Schmitt and I’m a professor in the Department of Evolution and Ecology at UC Davis.
So one of the big questions my lab is interested in is predicting how plants will respond to ongoing climate change. And we work particularly with the model plant Arabidopsis thaliana. And the other thing that we’re interested in is can we actually predict how plants will respond to novel environmental conditions.
So in one recent experiment we grew a bunch of recombinant inbred lines with different variant alleles that determine their chilling requirement for flowering. And, we grew them in environmental conditions where we simulated seasons of the year; so, we planted them in subjective August, September, October, November and so forth and we just ran them in real time through the year and we did that for Norwich, England which is a place where we could actually attain those winter temperatures in the chamber, and then Norwich, England with predicted climate for the year 2100 under one climate change scenario. And what we found is, first of all that there are dramatic differences in the response of these different lines to simulated climate change, so that both their flowering behavior and also their relative fitness will change as the climate warms.
So we’ve got 14 chamber compartments configured separately to control red/far-red ratio with LEDs. Red/far-red is important to plants because it’s a signal of nearby vegetation or future crowding by neighbors. But we’re interested in life history expression in plants, we’re interested in flowering time, and we wanted to make sure first of all just as a baseline that the red to far-red ratios were similar to what you’d see in natural sunlight because we’re trying to get as close to field conditions as possible. So that’s one reason.
The second reason, in the future we hope that we can actually manipulate these red to far-red ratios to simulate crowding, and one of the cool things about this is that you can fool plants into thinking they’re crowded when they’re not, or fool plants into thinking they’re not crowded when they are, and then you can look at their morphological responses and how that affects their performance. And you can do that for different genotypes, and see how genotypes differ in their red/far-red responses. So that’s something for the future.
One thing that we’re doing right now – it turns out that far-red as a signal for flowering can override the requirement for chilling in some varieties of Arabidopsis, so one of the ongoing experiments that we’re doing right now is we’re interested in looking at the behavior over time of the signaling pathways that induce a plant to flower in different genotypes, and with different histories of winter chilling.
A pulse of far-red will actually override the chilling requirement for flowering and so you can again fool these plants into flowering even though they haven’t been through winter conditions and then look at the gene expression profiles.
So we’re working with Arabidopsis because it’s a genetic model system, but as you know Arabidopsis is closely related to many important crops such as canola, and the gene networks elucidated in Arabidopsis also seem to be conserved across a number of different plant species. So, our hope is that this kind of approach could then be used to describe the response to novel environments of a whole variety in different species.