<i>Arabidopsis</i> type B cytokinin response regulators ARR1, ARR10, and ARR12 negatively regulate plant responses to drought

Significance Cytokinin regulates plant drought adaptation via a multistep component system consisting of histidine kinases, histidine phosphotransfer proteins, and type A and B response regulators (RRs). The functional dissection of individual members of cytokinin signaling and identification of their downstream targets in drought responses are of high importance to provide a complete picture of how cytokinin controls plant drought adaptation. Previous studies have identified functions of several histidine kinases, histidine phosphotransfer proteins, and type A RRs in drought responses of Arabidopsis ; however, the roles of type B RRs remain elusive. This comprehensive functional analysis of three type B RRs provides further insight into how cytokinin signaling regulates plant drought adaptation through the proposed yin-yang strategy, enabling efficient application of cytokinin biology in stress tolerance-oriented plant biotechnology.