The temperature-dependent changes of volatile oil content in Atractylodes lancea (Thunb.) DC detected by full-length transcriptomic and physiological approaches

The study investigates the effects of temperature variations on the volatile oil content and physiological responses of Atractylodes lancea, a medicinal herb known for its therapeutic properties. The research focuses on how different temperature regimes impact the accumulation of key secondary metabolites, such as β-eudesmol and atractylodin, and various physiological parameters in A. lancea. Plants were subjected to temperatures of 28, 34, and 40 °C for 2, 4, and 6 days. The study found that β-eudesmol content varied significantly with temperature and duration, showing the highest levels at 28 °C 2 days post-treatment and a decreasing trend with prolonged exposure. In contrast, atractylodin content peaked under different conditions, with notable increases at 34 °C after 4 days in stems and at 28 °C in rhizomes. Photosynthesis rates, intercellular CO2 concentration, stomatal conductance, and transpiration rates were also measured to understand the broader physiological impacts of temperature stress. Full-length transcriptome analysis using SMRT sequencing revealed significant changes in gene expression related to sesquiterpene biosynthetic pathways. Key enzymes involved in sesquiterpene production showed differential expression patterns, with typical temperatures favoring higher expression levels. The findings highlight the complex interplay between temperature and secondary metabolite production in A. lancea. Understanding these dynamics can inform cultivation practices to optimize the therapeutic potential of A. lancea by ensuring consistent quality in herbal products. The study underscores the importance of environmental factors in modulating plant physiology and secondary metabolite accumulation, providing insights for future research and agricultural practices.