Article Figures & Data
Figures
- Fig. 1.
Waving/coiling patterns for seedlings of wild type (ecotype Wassilewskija [Ws]) and rgr1. The roots are growing on the surface of agar (1%, w/v) plates. A to C, Wild-type seedlings growing on plates tilted by angles of +30°, 0°, or −30°. D to F, rgr1 seedlings oriented at the same angles.
- Fig. 2.
Logic of custom software for measurement of length and segment angles of roots. A key feature of the software is its ability to identify the edges of the root based on a user-defined threshold luminous intensity and record that pixel location. Black and white arcs denote segment limits as determined by the search routine of the software. The size of each segment is selected by the user and input as a searching radius. Black arcs indicate the limits of odd-numbered segments (1, 3, 5, etc.) and white arcs indicate the limits of even-numbered segments (2, 4, 6, etc.). Segment angle was determined by first finding the line connecting the edge points of the root at a given search distance, then determining the angle of the line connecting the midpoints of the two limit lines relative to vertical. The overlapping process used to define segment limits increases the resolution of angle measurement. By definition the segments remain a fixed distance relative to the root tip as the root elongates. Total length of each edge is measured from the tip to a user-defined basal point in the mature region of the root.
- Fig. 3.
Kinetics of the gravitropic response of a representative root of a wild-type seedling growing along the surface of a vertically oriented agar plate. Different-colored lines represent segments located at the stated distances from the tip. Arrows show the range of segments where the initial curvature originates. Inset images show the root curvature that the data characterize. A, Root gravistimulated by a counterclockwise rotation of 90°. B, Root gravistimulated by a clockwise rotation of 90°. Not all segments are plotted. deg, Degrees.
- Fig. 4.
Kinetics of the gravitropic response of a representative root of a rgr1 seedling growing along the surface of a vertically oriented agar plate. Different-colored lines represent segments located at the stated distances from the tip. Arrows show the segments where the initial curvature originates. Inset images show the root curvature that the data characterize. A, Root gravistimulated by a counterclockwise rotation of 90°. Arrow shows the range of segments involved in the initial downward curvature. B, Root gravistimulated by a clockwise rotation of 90°. Arrow shows the upward curvature of the more basipetal segments, whereas the gravitropic response of more apical segments dampens this upward curvature. deg, Degrees.
- Fig. 5.
Kinetics of the gravitropic response of a representative root of rgr1 growing through a block of agar. The root was gravistimulated by a clockwise rotation. The different lines represent segments located at the stated distances from the tip. deg, Degrees.
- Fig. 6.
Circumnutation patterns for roots growing through a block of agar. Data for the root-tip segment of a wild-type (A) and argr1 seedling (B) are plotted. deg, Degrees.
- Fig. 7.
Waving growth pattern for roots growing along the surface of an agar plate. The root-tip angle is plotted for a representative wild-type (A) and a rgr1 root (B). deg, Degrees.
Tables
- Table I.
Comparative gravitropism kinetics for roots of wild-type and rgr1 seedlings growing on the surface of vertically oriented agar plates
Seedling Type Clockwise Counterclockwise Lag Rate Lag Rate min ° h−1 min ° h−1 Wild type 22 ± 6 (n = 4) 22 ± 8 (n = 4) 29 ± 13 (n = 10) 16 ± 5 (n = 10) rgr1 25 ± 8 (n = 10) 2 ± 6-a(n = 10) 22 ± 8 (n = 8) 8 ± 5-a(n = 8)
