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A MORPHOGENETIC STUDY OF LEAF ABSCISSION IN PHASEOLUS
Author(s) -
Webster Barbara D.
Publication year - 1970
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1970.tb09835.x
Subject(s) - abscission , biology , phaseolus , pith , botany , cell division , microbiology and biotechnology , cell , biochemistry
Leaf abscission in Phaseolus vulgaris L., the red kidney bean, is presumed to involve a precisely regulated set of interlocking reactions, all of which are subject to control and many of which are detectable morphologically and histochemically. Four sequential stages which culminate in separation are distinct in the laminar abscission region. These include 1) pith cell breakdown, which may not be related to abscission; 2) cell division; 3) cellular differentiation; and 4) cortical and vascular cell breakdown. Correlation of the time and the nature of these structural changes with the period of effectiveness of certain applied growth regulators provides some interesting insights into the nature of the regulatory mechanisms in abscission. A reevaluation of some contemporary concepts of abscission, particularly the characterization of abscission as a senescence phenomenon, is suggested.