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La perception géotropique dans la coiffe des racines de Lentille
Author(s) -
PERBAL GÉRALD,
PERBAL PATRICK
Publication year - 1976
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1976.tb01870.x
Subject(s) - amyloplast , physics , mathematics , chemistry , biophysics , biochemistry , biology , plastid , chloroplast , gene
Geoperception in the Lentil Root Cap. — Previous analysis showed that, in its initial phase, the geotropic response of Lens culinaris L. roots cannot be explained by a simpleaction by sliding, pressure or contact of amyloplasts on a sensitive surface located along the longitudinal wall. In this study another mode of action is tested by considering the following parameters as functions of the roots inclination: (1) the distance ( d ) which the amyloplasts move; (2) their number of contacts (c̃) with parietal cytoplasm; (3) the variable (sin α) of the transversal component of the statolith weight (M̄× g sin α). It is shown that the initial rate of curvature (V̄), at the various angles, is related to the sedimentation of the amyloplasts by the equation V̄= a log b d̄c̄ sin α (where a and b are constants). The results obtained prove that the geotropic stimulation is dependent upon the sine of the angle (α) of the root inclination and explain the sine rule deviation. The role of statoliths is discussed in the light of recent literature on growth inhibitors which are involved in the geotropic reaction.