Tea-oil (Camellia oleifera Abel) is an important woody crop for producing high-quality edible oil, which has been extensively cultivated in an unattended manner and exposed to various light stresses. To gain insights into the tea-oil plant’s adaption to different light environments, leaf anatomical characteristics, chlorophyll fluorescence quenching kinetics, and antioxidant enzyme activities were investigated under high (HL), medium (ML), and low light intensity (LL) conditions. Metabolomic and transcriptomic analyses were also performed to reveal the changes in secondary metabolites and lipid profiles. The results showed that HL and ML had a rapid NPQ relaxation compared to LL. As light intensity decreased, the chlorophyll fluorescence yields and PSII photochemical efficiency improved during both the light-adapted steady-state and dark relaxation phases. ML and LL exhibited lower PSII activity and higher NPQ compared to HL, as instantaneous light intensity increased. The increased leaf thickness, elevated CAT activity, and the up-regulated synthetic pathways of flavonoids, lignans, tannins, and triterpenoids helped tea-oil plants survive under HL and ML. SOD and POD played an important role in acclimation to LL, resulting in a lower level of lipid oxidation. HL and ML promoted lipid biosynthesis, while LL inhibited fatty acid elongation, enhanced degradation pathways of triacylglycerol and fatty acids, and facilized sphingolipid metabolism. These findings shed light on the adaptive mechanism of tea-oil plant to varying light intensity environments. To further unravel the complex interactions among lipids, secondary metabolites and the antioxidant system, future study should focus on verifying the functions of differentially expressed genes identified in this study.

油茶（Camellia oleifera Abel）是生产优质食用油的重要木本作物，一直以来都以无人值守的方式大规模种植，并受到各种光照胁迫。为了深入了解茶油植物对不同光环境的适应，在高光强度 (HL)、中光强度 (ML) 和低光强度 (LL) 条件下研究了叶片解剖特征、叶绿素荧光猝灭动力学和抗氧化酶活性。还进行了代谢组学和转录组学分析，以揭示次级代谢物和脂质谱的变化。结果表明，与 LL 相比，HL 和 ML 的 NPQ 松弛较快。随着光强度的降低，叶绿素荧光产量和 PSII 光化学效率在光适应稳态和暗弛豫阶段都有所提高。随着瞬时光强度的增加，与 HL 相比，ML 和 LL 表现出较低的 PSII 活性和较高的 NPQ。叶片厚度的增加、CAT 活性的升高以及类黄酮、木酚素、单宁和三萜类化合物合成途径的上调有助于茶油植物在 HL 和 ML 下生存。SOD 和 POD 在 LL 的适应过程中发挥了重要作用，导致脂质氧化水平较低。HL和ML促进脂质生物合成，而LL抑制脂肪酸延伸，增强三酰甘油和脂肪酸的降解途径，并促进鞘脂代谢。这些发现揭示了茶油植物对不同光强度环境的适应机制。为了进一步揭示脂质、次生代谢物和抗氧化系统之间复杂的相互作用，未来的研究应集中于验证本研究中发现的差异表达基因的功能。