1. Plant Cell Biotechnology Laboratory, Korea Research Institute of Bioscience and Biotechnology, P.O. Box 115, Yusong, Taejon 305–600, Korea (Y.S.K., J.H.L., G.M.Y., H.S.C., S.-W.P., D.C., J.R.L., H.-S.P.);
2. Graduate School of Biotechnology, Korea University, Seoul 136–701, Korea (M.C.S.); and
3. Division of Life Sciences, Chungbuk National University, Cheongju 361–711, Korea (H.J.H.)