Plant Protect. Sci., 2002, 38(11):516-518 | DOI: 10.17221/10542-PPS

Ergosterol induces mobilization of internal calcium in tobacco cells

T. Kašparovský¹, M.-L. Milat², J.-P. Blein², L. Havel³, V. Mikeš¹

¹ Department of Biochemistry, Faculty of Science, Masaryk University, 611 37 Brno, Czech Republic

² Unité associée INRA/Université de Bourgogne 692, Laboratoire de Phytopharmacie et de Biochimie des Interactions Cellulaires, F-21065 Dijon, France

³ Department of Botany and Plants Physiology, Mendel University of Agriculture and Forestry, 613 00 Brno, Czech Republic

As for natural sterols, only ergosterol is recognized very specifically and sensitively (nM) by plants cells. Ergosterol interacts with tobacco suspension cells and trigger pH changes of extracellular medium, oxidative burst and synthesis of phytoalexins. Compared with the responses induced by cryptogein, a proteinaceous elicitor from Phytophthora sp., oxidative burst, DpH and phytoalexin accumulation were weaker with ergosterol. Cryptogein stimulated an apparent continuous uptake of external calcium within 40 min, whereas no net uptake of external calcium occurred upon the addition of ergosterol. However, the elicitation with either cryptogein or ergosterol resulted in an increase of the fluorescence of calcium green 1 in cytosol. The use of several inhibitors of calcium channels (La³⁺, TMB-8, verapamil, ruthenium red, nifedipine) and a protein-kinase inhibitors (staurosporin, NPC-15437, H-89) suggests that the elicitation with ergosterol includes the mobilization of internal calcium stores in vacuoles mediated by IP3 and some protein kinases.

Keywords: elicitor; ergosterol; calcium channels

Published: December 31, 2002  Show citation