Jiang Lu, Zhang Shilong, Niu Yuting, Yang Guangqiong, Zhao Jiachen, Liu Huishan, Xiong Minyu, Xie Lingyi, Mao Zhilei, Guo Tongtong, Yang Hong-Quan, Wang Wenxiu
Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China.
Shanghai Collaborative Innovation Center of Plant Germplasm Resources Development, College of Life Sciences, Shanghai Normal University, Shanghai 200234, China.
Plant Cell. 2025 Aug 4;37(8). doi: 10.1093/plcell/koaf196.
Cryptochromes (CRYs) are blue light photoreceptors that regulate various light responses in plants, including photomorphogenesis. Autophagy is a tightly controlled intracellular degradation pathway that plays a critical role in plant growth and development. CRY signaling inhibits the 26S proteasome-dependent degradation of LONG HYPOCOTYL 5 (HY5) through interactions with the CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1)-SUPPRESSOR OF PHYA-105 1 (SPA1) complex. However, whether CRY1 mediates the blue light-driven regulation of photomorphogenesis by regulating the autophagic degradation of HY5 remains unclear. Here, we show that CRY1 directly interacts with ATG8, a key player in selective autophagy, in a blue light-dependent manner in Arabidopsis (Arabidopsis thaliana). ATG8 and ATG5/ATG7 act genetically downstream of CRY1, but upstream of HY5, to regulate photomorphogenesis. In darkness, AUTOPHAGY-RELATED8 (ATG8) physically interacts with HY5 to facilitate its autophagic degradation and promote skotomorphogenesis. Under blue light, the CRY1-ATG8 interaction inhibits the ATG8-HY5 interaction, suppressing the nuclear export and co-localization of ATG8 and HY5 to the autophagosome, and HY5 degradation in the vacuole. This study reveals how CRY1-mediated blue light signaling regulates HY5 autophagy, which enables plants to fine-tune photomorphogenic development in response to light and nutrient availability.
隐花色素（CRYs）是蓝光光感受器，可调节植物中的各种光反应，包括光形态建成。自噬是一种严格控制的细胞内降解途径，在植物生长发育中起关键作用。CRY信号通过与组成型光形态建成1（COP1）-phyA-105抑制因子1（SPA1）复合体相互作用，抑制长下胚轴5（HY5）依赖26S蛋白酶体的降解。然而，CRY1是否通过调节HY5的自噬降解介导蓝光驱动的光形态建成调控仍不清楚。在这里，我们表明在拟南芥中，CRY1以蓝光依赖的方式直接与选择性自噬的关键因子ATG8相互作用。ATG8和ATG5/ATG7在遗传上作用于CRY1的下游，但在HY5的上游，以调节光形态建成。在黑暗中，自噬相关蛋白8（ATG8）与HY5发生物理相互作用，促进其自噬降解并促进暗形态建成。在蓝光下，CRY1-ATG8相互作用抑制ATG8-HY5相互作用，抑制ATG8和HY5向自噬体的核输出和共定位，以及液泡中HY5的降解。这项研究揭示了CRY1介导的蓝光信号如何调节HY5自噬，使植物能够根据光照和养分可用性微调光形态建成发育。
