Sheng Zhong1, Li-Jia Qu2,3. 1. State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing, 100871, China. 2. State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing, 100871, China. qulj@pku.edu.cn. 3. The National Plant Gene Research Center (Beijing), Beijing, 100101, China. qulj@pku.edu.cn.