The TaCLE24b peptide signaling cascade modulates lateral root development and drought tolerance in wheat.

Plant peptide hormones play an important role in regulating root development and stress responses. Here, we identify a root-derived CLAVATA3/Endosperm surrounding region-related (CLE) peptide TaCLE24b and its leucine-rich repeat receptor-like kinase CLAVATA1 (CLV1) TaCLV1, which together regulate the formation of lateral root primordium and the outgrowth of lateral root in wheat. Additionally, a loss-of-function mutation of TaSG-D1, encoding a Ser/Thr protein kinase glycogen synthase kinase 3 (STKc_GSK3), also enhances the formation of lateral root primordium and the outgrowth of lateral roots in wheat. Furthermore, TaCLV1 interacts with TaSG-D1, leading to phosphorylation and degradation of TaSG-D1. Whereas the presence of TaCLE24b enhances the binding affinity and phosphorylation ability of TaCLV1 to TaSG-D1, thereby positively fine-tuning lateral root development and contributing to drought tolerance in wheat. Overall, our findings provide new insights into the significance of the peptide signaling pathway in regulating lateral root development and responding to drought stress in wheat.