Peptide signals regulating leaf senescence

Leaf senescence is an essential physiological process which is accompanied by the transfer and recycling of nutrients from aging organs to growing tissues. This intricate process is finely orchestrated by multiple endogenous and exogenous elements, including leaf age, environmental signals, and developmental cues. Plant small peptides, serve as intercellular signaling molecules, which regulate processes like stem cell homeostasis, stress responses, immune responses, pollen-stigma recognition, and organ abscission. Recent studies revealed that small peptides are important regulators during leaf senescence progression. For example, CLE14 and CLE42 peptides function in the suppression of leaf senescence though modulating ROS and ethylene signals, respectively. SCOOP10 and SCOOP12 peptides, however, modulate leaf senescence via MIK2 receptor-like kinases in an antagonistic manner. In this review, we conclude recent research in modulating leaf senescence by small peptides, encompassing both positive and negative regulators. Our aim is to provide a deeper comprehension of the diverse signaling pathways engaging in leaf senescence.