Understanding Freeze-Tolerant Plants
University of Nebraska-Lincoln biochemist Rebecca Roston is working to identify the properties and pathways underlying a plant’s ability to thwart ice-cold temperatures, with the long-term goal of enabling scientists to engineer freeze-tolerant crops. Roston earned a five-year, nearly $850,000 Faculty Early Career Development Program award from the National Science Foundation to advance this work.
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[00:00:00.480]My name is Rebecca Roston.
[00:00:02.010]I'm an assistant professor here
[00:00:03.670]in the Department of Biochemistry
[00:00:05.240]and in the Center for Plant Science Innovation.
[00:00:08.460]Plants have a unique response to freezing.
[00:00:10.720]In a single cell responding to freezing,
[00:00:12.770]the first thing that happens is
[00:00:13.790]ice start crystallizing outside the cell.
[00:00:16.430]The cell experiences a severe dehydration.
[00:00:19.360]Organelles that had space in between them previously
[00:00:23.020]end up rubbing elbows, which can result in membrane fusions.
[00:00:26.870]While that's not a problem during the freezing event itself,
[00:00:29.520]when they thaw, they split open and break.
[00:00:33.340]And you've seen this probably if you've ever left a head
[00:00:35.520]of lettuce in the back of your refrigerator.
[00:00:37.710]While it's stiff and frozen, it's fine,
[00:00:39.890]but as soon as you take it out, it turns into a limp puddle.
[00:00:43.680]Membranes at their most important have to stay flexible.
[00:00:49.240]Things that are frozen solid are not flexible,
[00:00:51.270]and the same thing goes for membranes.
[00:00:52.730]In fact, membranes more so than most things
[00:00:55.170]because they're trying to ride this biological imperative
[00:00:57.920]between too much flexibility where they leak
[00:01:01.710]and therefore don't function,
[00:01:03.240]and too little flexibility where they shatter
[00:01:06.100]and therefore don't function.
[00:01:07.540]And they literally got a range
[00:01:09.610]at every composition of only a few degrees,
[00:01:14.320]where outside on any given Nebraska day,
[00:01:17.490]it can change by 40 degrees.
[00:01:20.400]What we're looking at is a specific membrane system
[00:01:22.860]in an organelle which helps to prevent that membrane fusion.
[00:01:28.170]So in the model plant that we work on,
[00:01:30.470]plants with this enzyme can survive
[00:01:33.150]an additional two degrees of freezing
[00:01:35.550]compared to other plants.
[00:01:37.460]Outside of our lab,
[00:01:38.293]there's a lot of people that are interested
[00:01:39.790]in membranes being more freezing tolerant,
[00:01:42.800]not only in plants of a variety of crop species,
[00:01:45.980]but also in our official systems.
[00:01:48.620]In the public outreach component we're trying to tell people
[00:01:51.990]about some of the latest biotechnology changes
[00:01:54.490]in plants that have affected their food sources.
[00:01:56.980]And for that, we've looked at a graphic novel.
[00:02:00.590]So far we've hired professional graphic novel artists
[00:02:03.580]that have worked on DC Comics and things like that,
[00:02:06.890]and they've helped us to tell the story of some
[00:02:09.900]of the biotechnology that people are seeing in their food.
[00:02:12.115](upbeat piano music)
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