1. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119234 Russia
2. Moscow State University, Faculty of Biology, Vorobovy Gory 1-12, Moscow, 119234 Russia
3. Botanisches Institut, Neuerheimer Feld 360, Heidelberg 69120,Germany
4. Institute of Botany III, University of Duesseldorf, Universitaetsstr. 1, 40225 Duesseldorf, Germany