1. National Key Laboratory of Plant Molecular Genetics (NKLPMG), Institute of Plant Physiology and Ecology (SIPPE), Shanghai Institutes for Biological Sciences (SIBS), Shanghai 200032, P. R. China.
2. University of Chinese Academy of Sciences (CAS), Shanghai 200032, P.R. China.
3. Department of Molecular Biology, Max Planck Institute (MPI) for Developmental Biology, D-72076 Tübingen, Germany.
4. Institute of Botany, Slovak Academy of Sciences, SK-845 23 Bratislava, Slovak Republic.