Another thread in the tangled knot of leaf senescence

The emergence of yellow and red hued foliage in plants, which we commonly associate with vegetal decline or a foreshadowing of winter, signals the progression of a process known as leaf senescence. It is characterised by a series of carefully orchestrated degradation events, which liberate nutrients from senescing tissues and redistribute them to growing organs such as young leaves and reproductive structures. As the timing and execution of this process is essential to maximising the viability of succeeding plant generations and fruit production, it has tremendous implications for the agricultural industry. In this issue of Physiologia Plantarum , Zhang et al. (2020) describes the way in which a novel microRNA (miRNA) affects the timing of leaf senescence in tomato ( Solanum lycopersicum ) by modulating biosynthesis of the phytohormone cytokinin.