Potassium mitigates salt-stress impacts on photosynthesis by alleviation of the proton diffusion potential in thylakoids

Author(s):  
Yanhui Che ◽  
Dayong Fan ◽  
Zihan Wang ◽  
Nan Xu ◽  
Huihui Zhang ◽  
...  
1984 ◽  
Vol 247 (5) ◽  
pp. F837-F847 ◽  
Author(s):  
D. Shiuan ◽  
S. W. Weinstein

Controversial evidence exists as to whether electroneutral Cl-OH exchange occurs across the proximal tubular brush border membrane of the mammalian kidney. To help resolve this controversy, we carried out a series of experiments using rabbit renal cortical brush border membrane vesicles to determine the effect of changes in pH on 36Cl uptake across this membrane. Reducing pH equally inside and outside of the vesicle stimulated Cl-Cl exchange as well as chloride uptake. A proton gradient (out greater than in) stimulated and caused an overshoot in unidirectional Cl uptake. All three of these processes were inhibited by 4-acetoamido-4-isothiocyano-2,2-disulfonic stilbene. Valinomycin with K+ out-in added to shunt any proton diffusion potential, minimally inhibited pH gradient-dependent Cl uptake, and carbonyl cyanide p-trifluoro-methoxyphenyl hydrazone (FCCP), added to increase the proton diffusion potential, minimally stimulated pH gradient-dependent Cl uptake. Sodium-glucose cotransport (an electrogenic system) was used to assess the efficacy of these ionophores. FCCP markedly enhanced and valinomycin markedly inhibited pH gradient stimulated sodium-glucose cotransport. Valinomycin added to vesicles with a 180/0 meq K+ out greater than in gradient stimulated less Cl uptake than a 6.0/7.5 pH out greater than in gradient. We conclude that these results provide strong evidence for the existence of an electroneutral Cl-OH exchanger or Cl-H symporter in this membrane.


2018 ◽  
Vol 51 (3) ◽  
pp. 51-68 ◽  
Author(s):  
M.K. Hasan ◽  
M.S. Islam ◽  
M.R. Islam ◽  
H.N. Ismaan ◽  
A. El Sabagh

Abstract A laboratory experiment regarding germination and seedling growth test was conducted with three black gram genotypes tested under three salinity levels (0, 75 and 150 mM), for 10 days, in sand culture within small plastic pot, to investigate the germination and seedling growth characteristics. Different germination traits of all black gram genotypes, like germination percentage (GP), germination rate (GR), coefficient of velocity of germination (CVG) greatly reduced, as well as mean germination time (MGT) increased with increasing salt stress. At high salt stress, BARI Mash-3 provided the highest GP reduction (28.58%), while the lowest was recorded (15.79% to control) in BARI Mash-1. Salinity have the negative impact on shoot and root lengths, fresh and dry weights. The highest (50.32% to control) and lowest reduction (36.39%) of shoot length were recorded in BARI Mash-2 and BARI Mash-1, respectively, under 150 mM NaCl saline conditions. There were significant reduction of root lengths, root fresh and dry weight, shoot length, shoot fresh and dry weight in all genotypes under saline condition. The genotypes were arranged as BARI Mash-1 > BARI Mash-3 > BARI Mash-2, with respect to salinity tolerance.


2018 ◽  
Vol 51 (1) ◽  
Author(s):  
Da Wei Zhang ◽  
Thi Soan Vu ◽  
Jun Huang ◽  
Chun Yu Chi ◽  
Yi Xing ◽  
...  

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