1. Institute for Molecular Plant Physiology and Biophysics, University Würzburg, Julius-von-Sachs Platz 2, D-97082 Würzburg, Germany.
2. Zoology Department, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.
3. Department of Plant Biochemistry, Free University Berlin, Koenigin-Luise-Strasse 12-16, D-14195 Berlin, Germany.
4. Lehrstuhl für Botanik, Technische Universität München, Am Hochanger 4, D-85354 Freising, Germany.