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Phases in potassium transport and their regulation under near‐equilibrium conditions in wheat seedlings
Author(s) -
Erdei Lásló,
Oláh Zoltán,
Bérezi Alajos
Publication year - 1984
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1984.tb04254.x
Subject(s) - chromosomal translocation , potassium , chemistry , shoot , biophysics , botany , biology , biochemistry , organic chemistry , gene
Potassium uptake and release in roots and translocation to the shoots were studied in 14‐day‐old winter wheat ( Tritictum aestivum L. cv. Martonvásári 8) of different K status. Transport processes were measured in the growth solutions for 5 h ensuring near‐equilibrium conditions. The uptake showed three phases: (1) at low external K + concentrations it increased with increasing concentrations and culminated at 0.1 m M : (2) between 0.1 and 1 m M it decreased, and (3) it increased again above 1 m M : The release of K + showed a constant low level below 1 m M while paralleling the uptake above that. The uncoupler 2,4‐dinitrophenol inhibited uptake phases (1) and (2), whereas it did not affect either phase (3) or K + release. Translocation showed similar patterns. It is concluded that phases (1) and (2) depend on metabolic energy while phase (3) is mostly passive. It is emphasized that different types of regulation seem to operate in the transport mechanism: i.e. limitation by transport sites, control by negative feedback and by K + /K + exchange, respectively.