Premium
WOUND RECOVERY BY PITH CELL REDIFFERENTIATION: STRUCTURAL CHANGES
Author(s) -
Sussex Ian M.,
Clutter Mary E.,
Goldsmith Mary Helen M.
Publication year - 1972
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.1537-2197.1972.tb10154.x
Subject(s) - pith , meristem , biology , auxin , xylem , cell division , botany , vascular tissue , phloem , microbiology and biotechnology , wound healing , vascular cambium , cellular differentiation , limiting , anatomy , cambium , shoot , cell , biochemistry , immunology , mechanical engineering , engineering , gene
The redifferentiation of tobacco pith cells was examined in two experimental systems: wounds recovering from an incision that severed vascular tissue of the stem, and induced differentiation of excised pith responding to indoleacetic acid supplied locally via pipets inserted into the tissue. In both systems there was an initial period during which cell division was resumed and the pith cells were cleaved into numerous small cells. This was followed by redifferentiation of some of the divided cells as tracheary elements and, especially in the stem, by the formation of a cambial meristem that produced further xylem and phloem. In the stem the size of the wound meristem decreased as the wound was made further from the shoot apex, and in the cultured pith tissue it was demonstrated that the size of the dividing zone increased with the concentration of auxin supplied. Auxin was, therefore, demonstrated to be limiting in the division phase of redifferentiation. The sequence of redifferentiation in the two experimental systems resembled the normal ontogeny of vascular tissues in the intact plant sufficiently that these systems could be used to investigate the relationship between cell differentiation and auxin transport.