ISOPEROXIDASES CORRELATED WITH CYTODIFFERENTIATION AND ORGANOGENESIS INDUCED IN EPIDERMAL EXPLANTS OF TOBACCO (PEROXIDASE, MORPHOGENESIS, CHEMO-REGULATION).
Item
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Title
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ISOPEROXIDASES CORRELATED WITH CYTODIFFERENTIATION AND ORGANOGENESIS INDUCED IN EPIDERMAL EXPLANTS OF TOBACCO (PEROXIDASE, MORPHOGENESIS, CHEMO-REGULATION).
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Identifier
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AAI8409403
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identifier
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8409403
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Creator
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KAY, LOU ELLEN.
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Contributor
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Dominick V. Basile
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Date
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1984
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Language
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English
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Publisher
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City University of New York.
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Subject
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Biology, Botany
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Abstract
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We have examined the isoperoxidase composition correlated with the histology of the organogenetic system of tobacco epidermal explants. These explants can be induced to produce vegetative buds, floral buds, or callus reproducibly and have been found in this study to have a wide range of isoperoxidases, some of which occur only in specific organ-forming tissues at very specific times. The occurrence of these can be correlated with specific stages as seen in the histological data. Six of these isoperoxidases could be correlated with unregulated cell division, as seen in callus formation. Four isoperoxidases were correlated with various aspects of wound healing, and another two were associated with cessation or repression of cell division and differentiation. An additional eight isoperoxidases could be correlated with specific stages of bud formation and development. One of these was found only while vegetative buds were initiated; another two were present all during the formation and development of the vegetative buds; and a fourth was only evident as the vegetative buds developed. A floral-bud-specific isoperoxidase was also seen; its presence correlated with stamen development. These correlations are the most extensive ever reported from a study of isoperoxidases and organogenesis. This was probably due to two features. First, a more exhaustive extraction method was used that yielded three fractions: soluble, ionically bound, and covalently bound, rather than the usual single soluble fraction. The ionically bound fraction contained many of the most interesting isoperoxidase bands. This is the first report of the potential importance of this fraction as related to organogenesis. The second methodological advantage of this study was electrophoresis (horizontal slab) utilizing acidically buffered polyacrylamide gels, a system that allowed simultaneous resolution of both anodic and cathodic isoperoxidases. In the course of this study both acidic and basic buffers were used. The differences in the results obtained were striking. Only two-thirds as many isoperoxidase bands were observed in the alkaline gels as compared to the acidically buffered gels. This appeared to be due to the pH optima of most isoperoxidases being at about 4.5, causing those with narrow ranges of pH-tolerance not to show any activity at alkaline pHs.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Biology
