Growth Distribution during Phototropism of Arabidopsis thaliana Seedlings

The elongation rates of two opposite sides of hypocotyls of Arabidopsis thaliana seedlings were measured during phototropism by using an infrared imaging system. In first positive phototropism, second positive phototropism, and red light-enhanced first positive phototropism, curvature toward the light source was the result of an increase in the rate of elongation of the shaded side and a decrease in the rate of elongation of the lighted side of the seedlings. The phase of straightening that followed maximum curvature resulted from a decrease in the elongation rate of the shaded side and an increase in the elongation rate of the lighted side. These data for the three types of blue light-induced phototropism tested in this study and for the phase of straightening are all clearly consistent with the growth rate changes predicted by the Cholodny-Went theory.

[1]  T. Baskin,et al.  Phototropism in Higher Plants — Controversies and Caveats1 , 1988 .

[2]  M. Iino.  Mediation of tropisms by lateral translocation of endogenous indole‐3‐acetic acid in maize coleoptiles , 1991 .

[3]  P. B. Green,et al.  High‐resolution measurement of growth during first positive phototropism in maize , 1985 .

[4]  K. L. Poff,et al.  Dependence of the phototropic response of Arabidopsis thaliana on fluence rate and wavelength. , 1989, Proceedings of the National Academy of Sciences of the United States of America.

[5]  K. L. Poff,et al.  Characterization of adaptation in phototropism of Arabidopsis thaliana. , 1991, Plant physiology.

[6]  Harry Smith,et al.  Analysis of growth rates during phototropism: modifications by separate light‐growth responses , 1987 .

[7]  J. Digby,et al.  The Phototropic Response of Avena Coleoptiles following Localized Continuous Unilateral Illumination , 1984 .

[8]  A. Leopold,et al.  Time course of auxin stimulations of growth. , 1970, Plant physiology.

[9]  E. Lipson,et al.  Blue-light reception in Phycomyces phototropism: evidence for two photosystems operating in low- and high-intensity ranges. , 1987, Proceedings of the National Academy of Sciences of the United States of America.

[10]  D. C. Gordon,et al.  Analysis of growth during phototropic curvature of cress hypocotyls , 1982 .

[11]  W. Briggs,et al.  Growth distribution during first positive phototropic curvature of maize coleoptiles , 1984 .

[12]  M. Evans.  What remains of the Cholodny-Went theory? , 1992, Plant, cell & environment.

[13]  V. Orbović,et al.  Kinetics for phototropic curvature by etiolated seedlings of Arabidopsis thaliana. , 1991, Plant physiology.