ACKNOWLEDGEMENTS

We thank Sören Werner and Gabi Grüschow for generating the arrmutants and Hana Martínková and Petra Amakorová for technical assistance with cytokinin profiling. We acknowledge funding by the Deutsche Forschungsgemeinschaft (DFG) (grant Schm 814-27/1 and Collaborative Research Centre 973, www.sfb.973). This work was supported by the Czech Science Foundation (No. 19-00973S) and from the European Regional Development Fund-Project ”Plants as a tool for sustainable global development” (No. CZ.02.1.01/0.0/0.0/16_019/0000827).