Effect of Gravity Compensation on the Geotropic Sensitivity of Avena Seedlings

Abstract

Oat seedlings were grown under conditions where the directional component of the gravity force vector was nullified by horizontal rotation (compensation). They showed greater curvature following transverse geostimulation than did stationary control plants or vertically rotated plants. A portion but not all of the curvature increase due to compensation was attributable to removal of counter geostimulation forces by compensation during the curvature development period. Though coleoptiles grown under compensation developed larger root systems, coleoptiles from these plants were no larger than those grown with vertical rotation. It is inferred from these experiments that nullification of the directional component of the gravitational force vector increases root growth and the response of coleoptiles to geostimulation.