Endoplasmic reticulum-localized CCX2 is required for osmotolerance by regulating ER and cytosolic Ca2+dynamics in Arabidopsis
Articolo
Data di Pubblicazione:
2018
Citazione:
Endoplasmic reticulum-localized CCX2 is required for osmotolerance by regulating ER and cytosolic Ca2+dynamics in Arabidopsis / M. Corso, F.G. Doccula, J.R.F. de Melo, A. Costa, N. Verbruggen. - In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA. - ISSN 0027-8424. - 115:15(2018 Apr 10), pp. 3966-3971.
Abstract:
Ca2+ signals in plant cells are important for adaptive responses to environmental stresses. Here, we report that the Arabidopsis CATION/Ca2+ EXCHANGER2 (CCX2), encoding a putative cation/Ca2+ exchanger that localizes to the endoplasmic reticulum (ER), is strongly induced by salt and osmotic stresses. Compared with the WT, AtCCX2 loss-of-function mutant was less tolerant to osmotic stress and displayed the most noteworthy phenotypes (less root/shoot growth) during salt stress. Conversely, AtCCX2 gain-of-function mutants were more tolerant to osmotic stress. In addition, AtCCX2 partially suppresses the Ca2+ sensitivity of K667 yeast triple mutant, characterized by Ca2+ uptake deficiency. Remarkably, Cameleon Ca2+ sensors revealed that the absence of AtCCX2 activity results in decreased cytosolic and increased ER Ca2+ concentrations in comparison with both WT and the gain-of-function mutants. This was observed in both salt and nonsalt osmotic stress conditions. It appears that AtCCX2 is directly involved in the control of Ca2+ fluxes between the ER and the cytosol, which plays a key role in the ability of plants to cope with osmotic stresses. To our knowledge, Atccx2 is unique as a plant mutant to show a measured alteration in ER Ca2+ concentrations. In this study, we identified the ER-localized AtCCX2 as a pivotal player in the regulation of ER Ca2+ dynamics that heavily influence plant growth upon salt and osmotic stress.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Ca2+ transport; cation/Ca2+ exchanger family; NaCl; Cameleon sensors; abiotic stress
Elenco autori:
M. Corso, F.G. Doccula, J.R.F. de Melo, A. Costa, N. Verbruggen
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