Cytokinin regulates root meristem activity via modulation of the polar auxin transport
K. Rfeidka, M. Simásková, J. Duclercq, J. Petrásek, E. Zaeímalová, S. Simon, J. Friml, M. Van Montagu, E. Benková, PNAS 106 (2009) 4284–4289.