1. Peking-Yale Joint Center for Plant Molecular Genetics and Agro-Biotechnology, National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871, China
2. Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520-8104
3. College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China