Photoreceptor signaling in plants: Phase separation, signal integration, and applications for stress-resilient crops

This is the authors' abstract. We don't add key points for this paper.

Light functions not only as the primary energy source for photosynthesis but also as a critical environmental signal regulating plant growth, development, and stress adaptation. Plants perceive changes in light quality, intensity, duration, and direction through specialized photoreceptors, including phytochromes, cryptochromes, phototropins, and UV RESISTANCE LOCUS 8 (UVR8), which collectively coordinate extensive transcriptional, physiological, and developmental responses. Recent advances in plant photobiology have revealed that photoreceptor signaling is regulated not only through canonical transcriptional pathways but also through dynamic subcellular organization mechanisms. In particular, increasing evidence indicates that activated photoreceptors can promote liquid-liquid phase separation (LLPS), contributing to the formation of biomolecular condensates such as photobodies and related signaling assemblies. These membraneless structures are associated with the spatial organization of central regulatory components, including the COP1/SPA complex, PHYTOCHROME-INTERACTING FACTORs (PIFs), and ELONGATED HYPOCOTYL 5 (HY5), thereby influencing signal transduction, protein stability, and transcriptional regulation. Emerging studies further demonstrate extensive interactions between photoreceptor signaling networks and other environmental and endogenous pathways, including temperature responses, drought and salinity stress, hormonal signaling, and circadian regulation. Together, these interconnected networks enable plants to coordinate developmental plasticity and environmental adaptation under fluctuating conditions. In this review, we summarize recent advances in photoreceptor perception mechanisms, signaling regulation, biomolecular condensate formation, and cross-regulatory interactions between light signaling and abiotic stress pathways. We further discuss current challenges and future opportunities for applying photoreceptor-associated regulatory networks to crop improvement strategies aimed at optimizing photoperiod adaptation, plant architecture, and stress resilience under climate change.