Anoxia-induced elevation of cytosolic Ca2+ concentration depends on different Ca2+ sources in rice and wheat protoplasts
2011 (English)In: Planta, Vol. 234, 271-280 p.Article in journal (Refereed) Published
The anoxia-dependent elevation of cytosolicCa2+ concentration, [Ca2+]cyt, was investigated in plants differing in tolerance to hypoxia. The [Ca2+]cyt was measuredby fluorescence microscopy in single protoplastsloaded with the calcium-fluoroprobe Fura 2-AM. Imposition of anoxia led to a fast (within 3 min) significant elevationof [Ca2+]cyt in rice leaf protoplasts. A tenfold drop in the external Ca2+ concentration (to 0.1 mM) resulted inconsiderable decrease of the [Ca2+]cyt shift. Rice root protoplasts reacted upon anoxia with higher amplitude. Addition of plasma membrane (verapamil, La3+ and EGTA) and intracellular membrane Ca2+-channel antagonists(Li+, ruthenium red and cyclosporine A) reduced the anoxic Ca2+-accumulation in rice. Wheat protoplasts responded to anoxia by smaller changes of [Ca2+]cyt. In wheat leaf protoplasts, the amplitude of the Ca2+-shift little depended on the external level of Ca2+. Wheat root protoplasts were characterized by a small shift of [Ca2+]cyt under anoxia. Plasmalemma Ca2+-channel blockers had little effect on the elevation of cytosolic Ca2+ in wheat protoplasts. Intact rice seedlings absorbed Ca2+ from the external medium under anoxic treatment. On the contrary,wheat seedlings were characterized by leakage of Ca2+. Verapamil abolished the Ca2?+influx in rice roots and Ca2+ efflux from wheat roots. Anoxia-induced [Ca2+]cyt elevation was high particularly in rice, a hypoxia-tolerant species. In conclusion, both external and internal Ca2+ stores are important for anoxic [Ca2+]cyt elevation in rice, whereas the hypoxia-intolerant wheat does not requireexternal sources for [Ca2+]cyt rise. Leaf and root protoplasts similarly responded to anoxia, independent of theirorgan origin.
Place, publisher, year, edition, pages
Springer, 2011. Vol. 234, 271-280 p.
Anoxic signalling, cytosolic calcium, Fluorescence microscopy, Oryza, Triticum
Natural Sciences Botany
Research subject Plant Physiology
IdentifiersURN: urn:nbn:se:su:diva-66075DOI: 10.1007/s00425-011-1396-xISI: 000293188600005OAI: oai:DiVA.org:su-66075DiVA: diva2:466844
ProjectsCalcium signalling under anoxia
authorCount :42011-12-162011-12-162012-01-12Bibliographically approved