1. Laboratory of Molecular Plant Physiology, Institute of Botany and Microbiology, K.U.Leuven, B–3001 Leuven, Belgium (W.V.d.E., M.C., R.V., K.L.R., W.L., A.V.L.); Aquatic Biology, KULAK IRC, 8500 Kortrijk, Belgium (M.C.); Protein Quality and Function Team, AgResearch Limited, Lincoln Research Centre, Christchurch 8140, New Zealand (S.C.)