Dissipative process and experimental retardation of the twisting in the growing plant cell wall effect of ethylene generating agent and colchicine a morphologic revaluation
1983
REP.G1870
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Title
Dissipative process and experimental retardation of the twisting in the growing plant cell wall effect of ethylene generating agent and colchicine a morphologic revaluation
Publication Date
1983
Call Number
REP.G1870
Summary
Growth modifying agents which retard longitudinal expansion and induce radial swelling in plant cells were used on specimens capable of rapid elongation, in order to analyze the degree of plasticity of elongating walls. Specimens were taken from hypocotyls of mung bean, the polylamellate walls of which had previously been studied along a defined growth gradient. Wall texture was analyzed by means of ultrastructural cytochemistry. The 3..dimensional aspect was checked by using a goniometric stage at the electron microscope. The effects of both ethrel and colchicine are twofold: 1) Maintenance of the structural order built by the elongating cell in its wall before treatment. The regular bow shaped patterns are not disorganized as they are in controls; 2) Occurrence, at the innermost part of the wall laid down under the influence of treatment, of a thick layer built by the same twisting process, but significantly retarded. Results confirm the proposed hypothesis that the elongating wall is a dissipative structure emphasizing on the cell being capable to build a temporary order in its wall (polylamellate and twisted pattern). This order is subsequently used up during elongation. The oriented growth is associated with an irreversible change from structural order to disorder. When elongation of the specimen is retarded, the swollen cell wall, though stretched, retains its youthful characteristics. Neither do the treatments provoke a ran\-domization of the subunits at the moment of assembly. The twisting process is retarded, indicating that the program of the oscillatory device is modulable and sensitive to environmental signals. The results indicate that the data from the literature concerning the effects of growth modifying agents ought to be revaluated by taking into account both the spatial and temporal aspects of structural changes. Data arc discussed in terms of cell morphogenesis and cholesteric pattern.
Journal Citation
v.46(3):301-310, BIOLOGIE CELLULAIRE
Contact Information
harvest@worldveg.org
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Research > Published Articles