Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium. tineke.casneuf@psb.ugent.be|Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium. tineke.casneuf@psb.ugent.be|Department of Plant Systems Biology, VIB, B-9052 Ghent, Belgium. tineke.casneuf@psb.ugent.be