Senescence-Related Receptor Kinase 1 (SENRK1) functions downstream of WRKY53 in regulating leaf senescence in Arabidopsis.

Receptor-like kinases (RLKs) are the most important class of cell surface receptors and play crucial roles in plant development and stress responses. However, few studies were reported about the biofunctions of RLK in leaf senescence. In the current study, we characterized a novel RLK-encoding gene senescence-related receptor kinase 1 (SENRK1), which was significantly down-regulated during leaf senescence. Notably, the loss-of-function senrk1 mutants displayed an early leaf senescence phenotype, while overexpression of SENRK1 significantly delayed leaf senescence, indicating that SENRK1 negatively regulates age-dependent leaf senescence in Arabidopsis. Furthermore, the senescence-promoting transcription factor WRKY53 is able to repress the expression of SENRK1. While the wrky53 mutant showed a delayed senescence phenotype as reported, the wrky53 senrk1-1 double mutant exhibited precocious leaf senescence, suggesting that SENRK1 functions downstream of WRKY53 in regulating age-dependent leaf senescence in Arabidopsis.