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Aquaporin functionality in relation to H + ‐ATPase activity in root cells of Capsicum annuum grown under salinity
Author(s) -
MartínezBallesta M. Carmen,
Martínez Vicente,
Carvajal Micaela
Publication year - 2003
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 - 10.1034/j.1399-3054.2003.00044.x
Subject(s) - aquaporin , fusicoccin , salinity , atpase , chemistry , pepper , biochemistry , membrane , ion transporter , biophysics , botany , biology , enzyme , food science , ecology
As water and nutrient uptake should be related in the response of plants to salinity, the aim of this paper is to establish whether or not aquaporin functionality is related to H + ‐ATPase activity in root cells of pepper ( Capsicum annuum L.) plants. Thus, H + ‐ATPase activity was measured in plasma membrane vesicles isolated from roots and aquaporin functionality was measured using a cell pressure probe in intact roots. Salinity was applied as 60 m M NaCl or 60 m M KCl, to determine which ion (Na + , K + or Cl − ) is producing the effects. We also investigated whether the effects of both salts were ameliorated by Ca 2+ . Similar results were obtained for cell hydraulic conductivity, Lp c , and H + ‐ATPase activity, large reductions in the presence at NaCl or KCl and an ameliorative effect of Ca 2+ . However, fusicoccin (an activator of H + ‐ATPase) did not alter osmotic water permeability of protoplasts isolated from roots. Addition of Hg 2+ inhibited both ATPase and aquaporins, but ATPase also contains Hg‐binding sites. Therefore, the results indicate that H + ‐ATPase and aquaporin activities may not be related in pepper plants.