NOTE: New end date is 5/31/2012, per PI (Ed., 2/3/2011)

NOTE: Extended to 5/31/2011 per NSSC info; original end date 3/14/2010 (9/2009)

NOTE: New end date is 5/31/2012, per PI (Ed., 2/3/2011)

NOTE: Extended to 5/31/2011 per NSSC info; original end date 3/14/2010 (9/2009)

NOTE: New end date is 5/31/2012, per PI (Ed., 2/3/2011)

NOTE: Extended to 5/31/2011 per NSSC info; original end date 3/14/2010 (9/2009)

A brief summary of the TAGES flight experiment launched in 2009:

Plants in space flight experience conditions that are distinctly unlike the earth-bound environments that have directed their evolution on Earth. This presents a unique opportunity to examine biological responses particularly those involved in integrating gravity as a force shaping biological systems. One of the consequences of exposure to any environment change is the expression of genes that allow survival in the new environment. In this case, understanding gene expression responses to spaceflight can illuminate the unique mechanisms employed in order to survive and adapt to an environment for which there is no evolutionary precedent. In this experiment gene expression will be monitored by genetically engineering plants with reporter genes driven by sensors that are sensitive to the potential stresses of spaceflight. These biological sensor plants are referred to as TAGES, an acronym for Transgenic Arabidopsis Gene Expression System.

Those reporter genes are visualized as a green fluorescent glow that can be seen by imaging systems built within the spaceflight hardware carrying the experiment. The fluorescence is due to the Green Fluorescent Protein (GFP) portion of the reporter gene. The experiment will launch as part of the APEX-Cambium payload, a joint payload with the Canadian Space Agency. The payload will launch within the mid deck of Atlantis then will be transferred to an Express Rack on the ISS, where it will see multiple tests and experiments using the TAGES fluorescent plants. Samples will be returned on later shuttle missions but a significant component of the experimental data will be the fluorescent images that will be transmitted from the ISS on a regular basis over the next few months. Additional experiments will be launched on future shuttle missions to the ISS, carrying new plant types to be analyzed.In the fluorescent images captured by the GIS hardware, the fluorescent green color in the image indicates the location of cells responding to a particular environmental stress with the induction of the GFP reporter gene. The deep red color indicates the natural fluorescence of chlorophyll in healthy plant cells. Thus, green fluorescence is an indicator of a specific stress response, while the red fluorescence provides information on the general health and vigor of the plant. The GFP reporters can be engineered to respond to a variety of specific stresses. Using these types of reporters enables us to evaluate the biological impact of spaceflight thereby obtaining biological relevance of that environment, not just the physical values that may be measured by local instruments.

The results from the first TAGES Flight experiment in 1999 (STS-93), and the results from several analog experiments with parabolic flight with (NASA’s RGO) indicated that the spaceflight presents a complex environment to terrestrial organisms, an environment outside their evolutionary experience. We have used the insights gained from those previous data to design a set of experiments to help us understand further the biological impact of spaceflight on complex terrestrial organisms. Our in-flight fluorescent imaging capabilities allow us to evaluate the responses almost in real time with the GFP reporters, and our returned material will be subjected to powerful biochemical and genetic evaluations that will enable us to evaluate the global genetic and metabolic responses of plants; every gene can be analyzed. Plants are higher eukaryotic organisms, and as such, share a surprising amount (>40%) of genetic information and metabolic processes with other higher eukaryotes – like humans. The molecular information we obtain from plants can also be applied to analogous processes in humans.

NOTE: Extended to 5/31/2011 per NSSC info; original end date 3/14/2010 (9/2009)

[ed. note: added to Task Book in 10/2009, when received info of separate grant award in 2007]