Affiliation: | (1) Laboratory of Cell Propagation, National Institute for Medical Research, The Ridgeway, Mill Hill, NW7 1AA London, UK;(2) Present address: Chemin de Borde-Rouge, Auzeville, Laboratoire de Biologie Moléculaire des Relations Plantes-Microorganismes, F-31320 Castanet-Tolosan Cedex, France |