Narciclasine,an inhibitor of protein synthesis. Action onAllium cepa L. root meristems

Summary Shortening of nucleologenesis time in a synchronous cell population, labelled as binucleate, by a caffeine pulse and fall in frequency of prophases are related to narciclasine inhibition of protein synthesis inAllium cepa L. meristems.Acknowledgments. We gratefully acknowledge Dr D. Vázquez and Dr A. Jiménez, from the Instituto de Bioquímica de Macromoléculas, for calling our attention to this protein synthesis inhibitor and providing us samples both of narciclasine andNarcissus bulbs. We also greatly appreciate Dr B. Rodriguez and Dr F. M. Panizo of the Instituto de Química Orgánica (Departamento de Productos Naturales) for their valuable help in isolation and characterization of narciclasine, and for laboratory facilities. The work has been partially supported by the Comisión Asesora para la Investigación Científica (Spain). A.S. has a fellowship awarded by the Instituto de Cultura Hispánica, Spain.