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Analysis of growth patterns during gravitropic curvature in roots of Zea mays by use of a computer-based video digitizerA computer-based video digitizer system is described which allows automated tracking of markers placed on a plant surface. The system uses customized software to calculate relative growth rates at selected positions along the plant surface and to determine rates of gravitropic curvature based on the changing pattern of distribution of the surface markers. The system was used to study the time course of gravitropic curvature and changes in relative growth rate along the upper and lower surface of horizontally-oriented roots of maize (Zea mays L.). The growing region of the root was found to extend from about 1 mm behind the tip to approximately 6 mm behind the tip. In vertically-oriented roots the relative growth rate was maximal at about 2.5 mm behind the tip and declined smoothly on either side of the maximum. Curvature was initiated approximately 30 min after horizontal orientation with maximal (50 degrees) curvature being attained in 3 h. Analysis of surface extension patterns during the response indicated that curvature results from a reduction in growth rate along both the upper and lower surfaces with stronger reduction along the lower surface.
Document ID
Document Type
Reprint (Version printed in journal)
External Source(s)
Nelson, A. J. (Ohio State University Columbus 43210, United States)
Evans, M. L.
Date Acquired
August 21, 2013
Publication Date
January 1, 1986
Publication Information
Publication: Journal of plant growth regulation
Volume: 5
ISSN: 0721-7595
Subject Category
Life Sciences (General)
Funding Number(s)
Distribution Limits
NASA Discipline Plant Biology
NASA Discipline Number 40-10
NASA Program Space Biology
Non-NASA Center