Live and Let Die: The Core Circadian Oscillator Coordinates Plant Life History and Pilots Leaf Senescence  Ulrike Zentgraf, Jasmin Doll, Lena Riester  Molecular Plant  Volume 11, Issue 3, Pages 351-353 (March 2018) DOI: 10.1016/j.molp.2018.02.001 Copyright © 2018 The Authors Terms and Conditions

Figure 1 The Circadian Clock Shares Many Modulators with the Senescence Regulatory Network. The central circadian oscillators are entrained by temperature and light, leading to diurnal rhythm of gene expression of a plethora of genes resulting in very diverse outputs. The period of the diurnal rhythm shortens from 24 h in young plants to 22–23 h in old plants (Kim et al., 2016). The central clock modulates carbohydrate and nitrogen metabolism, calcium, iron, and copper homeostasis as well as almost all hormone-signaling pathways. In turn, all metabolic processes involving these nutrients and hormones feed back to the core oscillator except GA, ethylene, and JA. Moreover, ROS homeostasis is triggered by CCA1 and EC (Lai et al., 2012). JA production as well as JA signaling is modulated by EC, in which JA production is reduced in EC mutants and LUX directly binds to the promoter of MYC2 to repress its expression. In turn, MYC2 regulates the expression of many SAGs. All actions related to the circadian clock are illustrated with blue arrows; black and gray arrows illustrate all actions related to senescence regulation; dashed lines indicate indirect effects. ABA, abscisic acid auxin; BR, brassinosteroids; CK, cytokinin; EC, evening complex; GA, gibberellin; JA, jasmonic acid; SA, salicylic acid; SAGs, senescence-associated genes. Molecular Plant 2018 11, 351-353DOI: (10.1016/j.molp.2018.02.001) Copyright © 2018 The Authors Terms and Conditions