Glow-in-the-Dark Plants on the ISS   
       
   May 6, 2013: The world is changing.  As greenhouse gases accumulate in the   
   atmosphere, global temperatures are on the rise. Sea levels inch upward as   
   polar ice retreats. Crops are growing in new places.   
       
   The world is changing.  The question is, can life change with it?   
       
   A batch of genetically engineered plants orbiting Earth on board the ISS may   
   have something to say about this.   
       
   "Our environment on Earth is changing, so we need to know how plants respond   
   to novelty," says molecular biologist Anna-Lisa Paul of the University of   
   Florida. "Spaceflight is outside the evolutionary experience of any   
   terrestrial organism.  Learning how plants respond to this unique environment   
   can also tell us how plants respond to new challenges on Earth."   
       
   http://www.youtube.com/watch?v=50LgSJhHCy4   
       
   How much novelty can a plant withstand? Glow-in-the-dark Arabidopsis has some   
   answers in this week's ScienceCast video: Play it!   
       
   Paul and colleague Rob Ferl are principal investigators of an experiment on   
   the ISS called TAGES, the Transgenic Arabidopsis Gene Expression System. For   
   the past two years, they have been using the ABRS experimental growth chamber   
   on board the space station to grow a garden of Arabidopsis thaliana, also   
   known as "thale cress." Cameras captured growth rates, root patterns, and a   
   strange green glow.   
       
   "We genetically modified the plant to glow when it is under stress," explains   
   Paul. "This can tell us a lot about how Arabidopsis adapts to the microgravity   
   environment."   
       
   Learning how plants adapt to new situations is crucial to climate change   
   research. In terms of global biomass, plants outweigh mammals by a factor of   
   1000.  They are a dominant part of the biosphere, playing a key role in the   
   carbon cycle.  Scientists and farmers have been experimenting with plants for   
   centuries, yet at a fundamental, genetic level, much remains unknown.   
       
   This is why Paul and Ferl have been putting Arabidopsis through its paces,   
   exposing the plant to extremes of pressure, temperature, and drought. Most of   
   their work has been done on Earth--but some extremes can only be found in   
   space.   
       
   "Removing gravity from the equation reveals unique aspects of cell growth and   
   development that we cannot discover in any other way," says Ferl.  "The   
   International Space Station is a great place to do this."   
       
   http://tinyurl.com/btpl73v   
       
   In a paper in the journal Plant Biology, Paul et al. compare plants grown in   
   space (FLT) to those grown on the ground (GC). Read itIn a recent issue of the   
   journal Plant Biology, they presented some of TAGES' first results.   
       
   "We have seen some things that surprised us," reports Paul.   
       
   Paul and Ferl inserted a glowing "reporter gene" into the DNA of Arabidopsis   
   that would be triggered by the plant hormone auxin.  Auxin is important to how   
   plants move and respond to their environment. By watching parts of Arabidopsis   
   light up, they tracked the action of the hormone at the cellular level without   
   actually dissecting the plants.   
       
   "We expected to find [auxin signals] in the gravity-sensing cells at the tip   
   of the roots.  Instead it showed up in the hypocotyls, the stem-like region   
   between the roots and leaves," she says.   
       
   An even bigger surprise was "skewing," a pattern of root movement that, on   
   Earth, helps plants navigate sticks and stones in soil as they search for   
   water and nutrients. Paul recalls being with Rob Ferl and watching some of the   
   first images of Arabidopsis come down from the ISS. "Are those roots skewing?"   
   we asked. The pattern was definitely there.   
       
   "It was pretty exciting," she says.  "This is something we thought only   
   happened in gravity."   
       
   Paul and Ferl also observed how Arabidopsis used light as a gravity-substitute   
   for telling "up" from "down." With lamps shining overhead, roots grew clearly   
   away from leaves, just like on Earth.   
       
   "Arabidopsis has proven remarkably adaptable to the space environment," notes   
   Ferl.   
       
   The details are not yet fully understood, but, thanks to TAGES, data at the   
   cellular and genetic level are now available for study.   
       
   "The more we learn," says Paul, "the better partners we can be for life in a   
   changing world."   
       
   Credits:   
       
   Author: Dr. Tony Phillips | Production editor: Dr. Tony Phillips | Credit:   
   Science@NASA   
       
   More information:   
       
   Advanced Biological Research System (ABRS)  -- read about the experimental   
   growth chamber in which the TAGES experiments took place   
       
   Transgenic Arabidopsis Gene Expression System (TAGES) -- NASA fact sheet   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.92   
    * Origin: NCS BBS - Houma, LoUiSiAna (1:3828/7)