Growth, phytohormone and transcriptome responses of Cunninghamia lanceolata seedlings to different light qualities

contents elevated under BL and FrL but reduced under RL, while ABA showed the opposite trend. Transcriptomic analysis showed that different light spectra regulated the expression of photoreceptors (PHYB, CRY1 and CRY2) and downstream factors (COP1, PIF3, HY5). BL stimulated flavonoid biosynthesis, RL enhanced phenylpropanoid and cell wall related pathways, and FrL induced carotenoid and stilbenoid metabolism. There results indicated that light spectra regulate seedling growth by integrating photoreceptor signaling, hormone dynamics, and secondary metabolism. The study improves our understanding of light responses in gymnosperms and provides a physiological and molecular basis for optimizing nursery light management and afforestation practices.