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Characterization of Alcohol Dehydrogenase Expression Under Conditions of Hypoxia and Calcium Signaling Inhibition.  M.A. Badon1, A.L. Paul2, and R.J. Ferl2. 1Clark Univ., Worcester, MA, 2Univ. of Florida, Gainesville, FL.

   Future manned space exploration to Mars and beyond will require the development of bioregenerative systems capable of supporting humans. However, plants can develop a response similar to the hypoxic response during spaceflight despite sufficient oxygen levels. Alcohol dehydrogenase (Adh), a hypoxia related protein, is expressed in the roots of Arabidopsis thaliana plants that have flown on shuttle missions. It has been shown that hypoxic conditions in addition to disruption of calcium signaling are necessary to replicate spaceflight Adh expression patterns in ground-based experiments. The role of calcium signaling and the effect of disrupting calcium signaling was explored using gadolinium chloride, a calcium channel blocker. Transgenic Arabidopsis lines expressing green fluorescent protein driven by the Adh promoter were subjected to hypoxic conditions for 48 hours. The Adh expression patterns were qualitatively characterized by reporter protein expression and expression was observed in flooded root tips after 48 hours and after 24 hours in gadolinium chloride treated root tips. The Adh expression patterns were also quantitatively characterized by Real Time-PCR (RT-PCR) and it was found that gadolinium chloride treatment limited the Adh expression response of the plant.  This research was supported by the Spaceflight and Life Sciences Training Program (SLSTP).