In:
Plant, Cell & Environment, Wiley, Vol. 33, No. 6 ( 2010-06), p. 943-958
Abstract:
Using confocal microscopy, X‐ray microanalysis and the scanning ion‐selective electrode technique, we investigated the signalling of H 2 O 2 , cytosolic Ca 2+ ([Ca 2+ ] cyt ) and the PM H + ‐coupled transport system in K + /Na + homeostasis control in NaCl‐stressed calluses of Populus euphratica . An obvious Na + /H + antiport was seen in salinized cells; however, NaCl stress caused a net K + efflux, because of the salt‐induced membrane depolarization. H 2 O 2 levels, regulated upwards by salinity, contributed to ionic homeostasis, because H 2 O 2 restrictions by DPI or DMTU caused enhanced K + efflux and decreased Na + /H + antiport activity. NaCl induced a net Ca 2+ influx and a subsequent rise of [Ca 2+ ] cyt , which is involved in H 2 O 2 ‐mediated K + /Na + homeostasis in salinized P. euphratica cells. When callus cells were pretreated with inhibitors of the Na + /H + antiport system, the NaCl‐induced elevation of H 2 O 2 and [Ca 2+ ] cyt was correspondingly restricted, leading to a greater K + efflux and a more pronounced reduction in Na + /H + antiport activity. Results suggest that the PM H + ‐coupled transport system mediates H + translocation and triggers the stress signalling of H 2 O 2 and Ca 2+ , which results in a K + /Na + homeostasis via mediations of K + channels and the Na + /H + antiport system in the PM of NaCl‐stressed cells. Accordingly, a salt stress signalling pathway of P. euphratica cells is proposed.
Type of Medium:
Online Resource
ISSN:
0140-7791
,
1365-3040
DOI:
10.1111/pce.2010.33.issue-6
DOI:
10.1111/j.1365-3040.2010.02118.x
Language:
English
Publisher:
Wiley
Publication Date:
2010
detail.hit.zdb_id:
391893-2
detail.hit.zdb_id:
2020843-1
SSG:
12
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