Gibberellin signalling mediates nucleocytoplasmic trafficking of Sucrose Synthase 1 to regulate the drought tolerance in rice.

The Green Revolution (GR) has substantially improved cereal crop yields and enhanced adaptation to diverse environmental challenges. However, the molecular and cellular mechanisms involving GR-related genes that regulate drought tolerance in plants remain largely unclear. Here, we reveal that the gibberellin (GA) signalling repressor SLENDER RICE 1 (SLR1) negatively regulates the abundance of the dehydration-responsive protein OsBURP3 to enhance drought tolerance in rice. OsBURP3 facilitates the translocation of Sucrose Synthase 1 (OsSUS1), from the cytosol to the nucleus, thereby decreasing the sucrose content. Mutation of OsBURP3 reduces the nucleus accumulation of OsSUS1 to enhance drought tolerance. SLR1 also competitively associates with OsBURP3 in the nucleus to release OsSUS1 back into the cytosol, resulting in elevated sucrose content. Cytological evidences confirm that sucrose contributes to the fine-tuning of the stomata aperture in rice leaves. Collectively, these findings provide a comprehensive framework for understanding the role of GA in regulating drought tolerance by mediating sucrose metabolism in crops.