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MAGNETOPHORETIC INDUCTION OF CURVATURE IN FLAX ROOTS -RESULTS FROM STS-107.  K.H. Hasenstein¹, O.A. Kuznetsov², P. Scherp¹, and Z. Ma¹.  ¹Biology Dept., Univ. Louisiana Lafayette, LA 70504-2451; ²Physics Dept., Univ. Missouri, Columbia, MO 65211

   The objective of this Space Shuttle experiment was to evaluate in the absence of gravity the relationship between a laterally applied magnetophoretic force, induced curvature, cytoskeletal organization in microgravity-grown roots and most importantly, the distribution of amyloplasts in the root columella. The magnetophoretic force was applied using a High Gradient Magnetic Field (HGMF) that was generated by steel wedges between NdFeB magnets. Based on downlinked images from orbit we were able to confirm that the hardware worked flawlessly. The seeds germinated at the expected time and grew at initially the same rate in both directions from the seed cassettes. The growth rate and elongation pattern of the root tips changed as they approached the HGMF. Perpendicular curvature away from the wedges could not be detected, but the video images did not show a single root growing past the wedge (highest point in force field). Unfortunately, amyloplast distribution and cytoskeletal structure could not be evaluated. Clinorotated roots in ground controls curved away from the HGMF zone as the roots approached the wedge. In contrast, roots grown in microgravity did not cross the HGMF zone on their growth trajectory. Our data indicate that the effect of the magnetic force may have been stronger in microgravity than in ground controls and suggests differences between microgravity and clinorotation. 

(Supported by NASA: NAG10-0190)