SEssion 06 Morphogenesisin vitro

Elicitation of tobacco cells with ergosterol activates a signal pathway including mobilization of internal calcium

Abstract Ergosterol interacts with tobacco suspension ( Nicotiana tabacum ) cells and triggers 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 and ΔpH changes were weaker whereas phytoalexin accumulation was higher 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 both cryptogein and ergosterol resulted in an increase of the fluorescence of calcium green 1 in cytosol. The use of…