Institution: | (1) Plant Science Institute, Department of Biology, University of Pennsylvania, 19104 Philadelphia, PA, USA;(2) Biology Department, Brookhaven National Laboratory, 11973 Upton, NY, USA;(3) Present address: Department of Biology, Queen's University, K7L 3N6 Kingston, Ontario, Canada;(4) Present address: International Centre for Genetic Engineering and Biotechnology, 110 067 New Delhi, India |