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FROM HORMONE SIGNAL, VIA THE CYTOSKELETON, TO CELL GROWTH IN SINGLE CELLS OF TOBACCO
Author(s) -
Vissenberg Kris,
Quelo AnneHelene,
Gestel Kristin,
Olyslaegers Geert,
Verbelen JeanPierre
Publication year - 2000
Publication title -
cell biology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.932
H-Index - 77
eISSN - 1095-8355
pISSN - 1065-6995
DOI - 10.1006/cbir.1999.0516
Subject(s) - microbiology and biotechnology , cytoskeleton , signal (programming language) , chemistry , hormone , growth hormone , cell , biology , computer science , biochemistry , programming language
Abstract Cultured mesophyll protoplasts of Nicotiana tabacum L. can be hormonally induced into different developmental pathways. In a medium containing auxins (NAA) and cytokinins (BAP) cells divide and eventually give rise to calli. When only auxins are present cells elongate and finally differentiate into very long tubular cells. We focused on the sequence of events leading to elongation. When cultured in a high (1mg/l) auxin concentration elongating cells seem to pass a certain threshold and increase their nuclear DNA up to about 16C. Cells cultured in a low (0.065mg/l) auxin concentration only have C‐values up to 4C, are unable to pass this threshold and finally fail to elongate. Besides the concentration dependence of the auxin signal, the efflux of auxin seems to be necessary for elongation since addition of TIBA drastically reduces the amount of elongating cells. Concomitant with the changes in nuclear physiology, auxin‐induced axiality is seen as sequential rearrangements of microtubules and actin‐filaments and of cell wall cellulose microfibrils from ‘randomly’ arranged in spherical cells to an orientation perpendicular to the long axis of elongating cells.