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Kripkyy Oleg Kerkeb Loubna Molina Anabel Belver Andrés Rodríguez-Rosales Pilar Donaire Juan Pedro 《Plant Cell, Tissue and Organ Culture》2001,66(1):41-47
The effects of NaCl-adaptation and NaCl-stress on in vivo H+ extrusion and microsomal vanadate- and bafilomycin-sensitive ATPase and PPase activities were studied in tomato cell suspensions.
Acidification of the external medium by 50 mM NaCl-adapted and non-adapted (control) tomato cells was similar. Extracellular
acidification by both types of cells during the first hour of incubation with 2 μM fusicoccin (FC) in the presence of 100
mM NaCl was lightly increased while in the presence of 100 mM KCl it was increased by 3 (control)- and 6.5 (adapted)-fold.
Extracellular alkalinization after 2 h of cell incubation in 100 mM NaCl indicated the possibility that a Na+/H+ exchange activity could be operating in both types of cells. Moreover, acidification induced by adding 100 mM NaCl + FC to
non-adapted cells was relatively less affected by vanadate than that induced by 5 mM KCl + FC, which suggested that salt stress
could induce some component other than H+ extrusion by H+-ATPase. In addition, no differences were observed in microsomal vanadate-sensitive ATPase activity among control, NaCl-adapted
and NaCl-stressed cells, while K+-stimulated H+-PPase and bafilomycin-sensitive H+-ATPase activities were higher in microsomes from NaCl-adapted than in those from control cells. Likewise, the stimulation
of in vivo H+ extrusion in NaCl adapted cells under NaCl or KCl stress in the presence of FC occurred with an inhibition of H+-PPase and bafilomycin-sensitive H+-ATPase activities and without changes in the vanadate-sensitive H+-ATPase activity. These results suggest that the stimulation of tonoplast proton pumps in NaCl-adapted cells, without changes
in plasmalemma H+-ATPase, could serve to energize Na+ efflux across the plasmalemma and Na+ fluxes into vacuoles catalyzed by the Na+/H+ antiports.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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