1. State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, National Center for Plant Gene Research (Beijing); China Agricultural University; Beijing 100094 People's Republic of China
2. Water Technology Centre, Indian Agricultural Research Institute; New Delhi 110 012 India
3. Department of Botany and Plant Sciences, Institute for Integrative Genome Biology, 2150 Batchelor Hall; University of California; Riverside CA 92521 USA