TgFbox1-TgNAC2-TgWIN1 module regulates petal senescence by fine-tuning cuticular wax biosynthesis in tulip

Flower aging, or senescence, is generally accompanied by petal dehydration/wilting. The cuticle functions as a barrier to withhold water for plant organs. However, little is known about how the cuticle modifies the process of petal development. Here, we report that cuticular wax is dynamically changed during petal senescence and wax coverage on petals is coordinated with the expression of TgWIN1. Functional identification indicates that TgWIN1 positively regulates wax accumulation and delays petal senescence. TgNAC2 promotes petal senescence by inhibiting TgWIN1 expression in senescent petals, while TgFbox1 degrades TgNAC2 protein accumulation via ubiquitination. Additionally, both abscisic acid (ABA) and ethylene contribute to petal senescence by promoting TgNAC2 expression but inhibiting TgFbox1 expression, respectively. Thus, we propose an ABA/ethylene-mediated TgFbox1-TgNAC2-TgWIN1 module that precisely regulates the cuticular wax biosynthesis and petal senescence, offering potential targets for optimizing flower longevity and wax biosynthesis in plants.