Scientific Research and Essays Vol. 2 (1), 013-015, January 2007          
ISSN 1992-2248 © 2007 Academic Journals

Short Communication

Evidence for the presence of two components of the root transmembrane potential of a halophyte Sesuvium. portulacastrum (L) L grown under saline conditions

B. Moseki

University of Botswana, Deparment of Biological Sciences, Private Bag UB 00704, Gaborone, Botswana. E-mail: mosekib@mopipi.ub.bw.

Accepted 19 December, 2006

This study has shown that the root cell potential difference (PD) has two components. One component (diffussional) was unaffected by the increasing NaCl concentration in the growth medium, while the other component (electrogenic) was affected by the NaCl concentration mostly above 200 mol m^-3. The component of the PD which disappeared after excision appeared to depend on metabolic activity, as cyanide (a metabolic inhibitor) completely removed it. This component would appear to be due to the activity of an electrogenic pump, possibly, powered by ATP.  

Key words: Sesuvium portulacastrum, salinity, electrogenic pumps, halophyte.