1. Federal Institute of Technology (Eidgenössische Technische Hochschule [ETH]) Zurich, Institute of Plant Sciences, Experimental Station Eschikon 33, CH–8315 Lindau, Switzerland (M.B., S.B., P.Z., G.I.Z.);
2. Federal Institute of Technology (ETH) Zurich, Institute of Plant Sciences, Universitätsstrasse 2, CH–8092 Zurich, Switzerland (N.A.);
3. Max-Planck-Institute of Molecular Plant Physiology, D–14424 Potsdam, Germany (L.W.); and
4. PlantTec Biotechnology, Hermannswerder 14, D–14473 Potsdam, Germany (J.W.R.)