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A gradient of endogenous calcium forms in mucilage of graviresponding roots of Zea maysAgar blocks that contacted the upper sides of tips of horizontally-oriented roots of Zea mays contain significantly less calcium (Ca) than blocks that contacted the lower sides of such roots. This gravity-induced gradient of Ca forms prior to the onset of gravicurvature, and does not form across tips of vertically-oriented roots or roots of agravitropic mutants. These results indicate that (1) Ca can be collected from mucilage of graviresponding roots, (2) gravity induces a downward movement of endogenous Ca in mucilage overlying the root tip, (3) this gravity-induced gradient of Ca does not form across tips of agravitropic roots, and (4) formation of a Ca gradient is not a consequence of gravicurvature. These results are consistent with gravity-induced movement of Ca being a trigger for subsequent redistribution of growth effectors (e.g. auxin) that induce differential growth and gravicurvature.
Document ID
Document Type
Reprint (Version printed in journal)
Moore, R. (Baylor University Waco, Texas 76798, United States)
Fondren, W. M.
Date Acquired
August 21, 2013
Publication Date
January 1, 1988
Publication Information
Publication: Annals of botany
Volume: 61
ISSN: 0305-7364
Subject Category
Life Sciences (General)
Funding Number(s)
Distribution Limits
NASA Discipline Number 40-10
Non-NASA Center
NASA Program Space Biology
NASA Discipline Plant Biology