1. Department of Physiology and Biophysics, 346-D Med Sci I, University of California, Irvine, California 92697-4560
2. U.S. Department of Agriculture–Agricultural Research Service, Eastern Regional Research Center, 600 E. Mermaid Lane, Wyndmoor, Pennsylvania 19038-8598
3. Department of Plant Pathology, University of California, Riverside, California 92521
4. Department of Molecular Genetics of Industrial Microorganisms, Wageningen Agricultural University, Dreijenlaan 2, 6703 HA Wageningen, The Netherlands