Final destination: Senescence—NtNAC56 and jasmonic acid in the regulation of leaf senescence in tobacco

Abstract

Leaf senescence is the timely coordinated program throughwhich leaf tissue dies. This program is the last stage of leaf development, when nutrients are recycled and mobilized to sinktissues. Senescence triggers leaf chlorosis (“yellowing”), the accumulation of reactive oxygen species (ROS), and the disassembly of the photosynthetic apparatus (Krieger-Liszkayet al. 2019). The latter involves chloroplast dismantling, leading to chlorophyll loss and thylakoid membrane reorganization (Domínguez and Cejudo 2021). Thus, senescencereduces the overall photosynthetic capacity of the leaf. Dueto its impact on leaf physiology and the productivity of thewhole plant, efforts have been made to understand the molecular signals regulating leaf senescence (Zhou and Yang2023). Delaying senescence, particularly under stress conditions, can increase plant yield and resilience, relevant traitsfor crop improvement in the current climate change scenario