Effect of NaCl on leaf H^sup +^-ATPase and the relevance to salt tolerance in two contrasting poplar species
During a 30-day period of increasing salinity, we examined the effects of NaCl on leaf H^sup +^-ATPase and salinity tolerance in 1-year-old plants of Populus euphratica Oliv. (salt resistant) and P. popularis 35-44 (P. popularis) (salt sensitive). Electron probe X-ray microanalysis of leaf mesophyll...
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Published in | Trees (Berlin, West) Vol. 24; no. 4; p. 597 |
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Main Authors | , , , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Heidelberg
Springer Nature B.V
01.08.2010
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Subjects | |
Online Access | Get full text |
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Summary: | During a 30-day period of increasing salinity, we examined the effects of NaCl on leaf H^sup +^-ATPase and salinity tolerance in 1-year-old plants of Populus euphratica Oliv. (salt resistant) and P. popularis 35-44 (P. popularis) (salt sensitive). Electron probe X-ray microanalysis of leaf mesophyll revealed that P. euphratica had a higher ability to retain lower NaCl concentrations in the cytoplasm, as compared to P. popularis. The sustained activity of H^sup +^ pumps (by cytochemical staining) in salinised P. euphratica suggests a role in energising salt transport through the plasma membrane (PM) and tonoplast. Salt-induced alterations of leaf respiration, ATP content and expression of PM H^sup +^-ATPase were compared between the two species. Results show that P. euphratica retained a constant respiratory rate, ATP production and protein abundance of PM H^sup +^-ATPase (by Western blotting) in salt-stressed plants. P. euphratica was able to maintain a comparatively high capacity of ATP hydrolysis and H^sup +^ pumping during prolonged salt exposure. By contrast, the activity and expression of PM H^sup +^-ATPase were markedly decreased in P. popularis leaves in response to salt stress. Furthermore, NaCl-stressed P. popularis plants showed a marked decline of respiration (70%) and ATP production (66%) on day 30. We conclude that the inability of P. popularis to transport salt to the apoplast and vacuole was partly due to the decreased activity of H^sup +^ pumps. As a consequence, cytosolic ion concentrations were observed to be comparatively high for an extended period of time, so that cell metabolism, in particular respiration, was disrupted in P. popularis leaves.[PUBLICATION ABSTRACT] |
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ISSN: | 0931-1890 1432-2285 |
DOI: | 10.1007/s00468-010-0430-0 |