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Biophysical basis of growth promotion in primary leaves of Phaseolus vulgaris L. by hormones versus light: solute accumulation and the growth potentialRapid cell enlargement in primary leaves of bean is induced by bright white light (WL), gibberellic acid (GA3) or the cytokinin N6-benzyladenine (BA). In previous studies it has been show that all three agents cause an increase in wall extensibility, although by different mechanisms. Here we examine the effects of the three growth promoters on the osmotic potential difference (delta Psi), the accumulation of solutes (delta TSC), the wall yield threshold (Y) and the growth potential (delta Psi -Y). With GA3 and BA, but not WL, there was a rapid decline in delta Psi as measured by the osmotic concentration of expressed sap. Unlike WL, neither GA3 nor BA promoted the accumulation of osmotic solutes. The decline in delta Psi, however, was apparently counteracted by a decline in Y since the growth potential, as measured by the external-osmoticum method, remained unchanged. It is concluded that WL, GA3 and BA all promote cell enlargement of bean leaves by increasing one cellular growth parameter, wall extensibility. Only WL, however, promotes osmotic adjustment during growth.
Document ID
20040090067
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Brock, T. G.
(University of Michigan Medical School Ann Arbor 48109-0618, United States)
Cleland, R. E.
Date Acquired
August 21, 2013
Publication Date
October 1, 1990
Publication Information
Publication: Planta
Volume: 182
Issue: 3
ISSN: 0032-0935
Subject Category
Life Sciences (General)
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Program Space Biology
NASA Discipline Plant Biology
NASA Discipline Number 29-20

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