Circadian control of <i>ORE1</i> by PRR9 positively regulates leaf senescence in <i>Arabidopsis</i>

Abstract

Significance The circadian clock is involved in aging in animals, where mutations in core clock genes accelerate aging. However, little is known about the relationship between aging and the circadian clock in plants. Using the well-studied process of leaf senescence in Arabidopsis , a higher plant, as a model for aging, we show that the circadian clock has a critical role in regulating the aging process in plants. Specifically, we show that PSEUDO-RESPONSE REGULATOR 9 (PRR9), a core clock component, positively regulates leaf senescence. ORESARA 1 ( ORE1 ), an aging regulator, is controlled by PRR9 via direct transcriptional activation and indirectly by suppressing miR164 , a posttranscriptional repressor of ORE1 , thus forming a coherent feed-forward regulatory loop.