Retraction to: Nature Plants, published online 3 January 2018.

This Letter is being retracted because, in follow-up experiments, key aspects of the original results have not been able to be replicated. The accuracy of the Myb1 and other sequencing information cannot be confirmed; the accuracy of the viral-induced gene silencing (VIGS) analysis, the identity of specimens in phenotype photographs and CPC gene sequencing and expression also cannot be confirmed; amplification of CPC, the supposed Myb1 regulator using the reported DNA and primers, cannot be repeated; and the reported 5’ sequence immediately upstream of Myb1 cannot be independently identified.

Mark Rausher agrees to the Retraction. We were unable to obtain a response from Peng Jiang.