[1] Univ Munich LMU, Inst Genet, D-82152 Martinsried, Germany
[2] Univ Basel, Inst Bot, Sect Plant Physiol, CH-4056 Basel, Switzerland
[3] Inst Expt Bot AS CR, Prague 16502 6, Lysolaje, Czech Republic
[4] Univ Cambridge, Sainsbury Lab, Cambridge CB2 1LR, England
[5] Univ Tubingen, ZMBP Zentrum Mol Biol Pflanzen, Forschungsgrp Pflanzenbiochem, D-72076 Tubingen, Germany
[6] Australian Natl Univ, Canberra, ACT 0200, Australia