1. Department of Molecular Genetics, National Institute of Agrobiological Resources, Tsukuba, Ibaraki 305–8602, Japan (G.K.A., M.Y., R.H., A.M., H.H.); and
2. Laboratory of Plant Molecular Biology, RIKEN Tsukuba Institute, Tsukuba, Ibaraki 305–0074, Japan (M.K.)