K-42 analysis of sodium-induced potassium efflux in barley: mechanism and relevance to salt tolerance
Dev T Britto, Sasha Ebrahimi-Ardebili, Ahmed M Hamam, Devrim Coskun, Herbert J Kronzucker
NEW PHYTOLOGIST | WILEY | Published : 2010
*Stimulation of potassium (K(+)) efflux by sodium (Na(+)) has been the subject of much recent attention, and its mechanism has been attributed to the activities of specific classes of ion channels. *The short-lived radiotracer (42)K(+) was used to test this attribution, via unidirectional K(+)-flux analysis at the root plasma membrane of intact barley (Hordeum vulgare), in response to NaCl, KCl, NH(4)Cl and mannitol, and to channel inhibitors. *Unidirectional K(+) efflux was strongly stimulated by NaCl, and K(+) influx strongly suppressed. Both effects were ameliorated by elevated calcium (Ca(2+)). As well, K(+) efflux was strongly stimulated by KCl, NH(4)Cl and mannitol , and NaCl also stim..View full abstract
We thank M. Butler at the McMaster University Nuclear Reactor and the Centre for Addiction and Mental Health (CAMH) cyclotron team, University of Toronto, for providing radiotracers. Funding for this work was provided by the University of Toronto, the Natural Sciences and Engineering Research Council of Canada (NSERC), the Canada Research Chair (CRC) program, and the Canadian Foundation for Innovation (CFI).