1. Instituto de Biologı́a Molecular y Celular de Plantas, Universidad Politécnica de Valencia, Consejo Superior de Investigaciones Cientı́ficas, 46022 Valencia, Spain (M.A.P.-A., J.L., J.C.); and
2. Department of Energy, Plant Research Laboratory, and Department of Biochemistry, Michigan State University, East Lansing, Michigan 48824 (P.J.G.)