1. Professor in the Laboratoire de Physiologie Végétale, Université de Rennes I, Campus de Beaulieu, 35042 Rennes Cedex, France. A.
2. Professor at the Institute of Fisheries, University of Tromso, P.O. Box 3083 Guleng, N-9001 Tromso, Norway.
3. Research molecular biologist in the Plant Growth Laboratory and Department of Agronomy and Range Science, University of California, Davis 95616.
4. Research biochemist in the Plant Growth Laboratory and Department of Agronomy and Range Science, University of California, Davis 95616.
5. Professor in the Plant Growth Laboratory and Department of Agronomy and Range Science, University of California, Davis 95616.