| Summary: | Research Highlights: Warming alters the chemical composition of <i>Cunninghamia lanceolata</i> (Lamb.) Hook, resulting in increased production of macromolecular compounds that protect against heat stress. Background and Objectives: Low latitude forests are experiencing obvious climatic warming; however, the plant physiological responses to warming are not well understood. As warming induces moisture stress, we hypothesized that warming activates metabolites (i.e., lipids, phenolic compounds, amino acids) and causes damage to the leaves, exemplified by the increased concentrations of reactive oxygen species. Materials and Methods: We conducted a warming experiment in a <i>C. lanceolata</i> plantation. Plant physiological traits associated with nutrient status, reactive oxygen species, antioxidant enzymes species, and metabolites were measured. Results: Warming altered the chemical composition of <i>C. lanceolata</i> as it increased C:N ratios of leaves and roots. In particular, the concentrations of N and P in leaves and roots were significantly decreased under the warming condition, which might be related to the biomass production, namely, a dilution effect. Under the warming condition, most of the phospholipid compounds and proteins significantly increased. Leaf C, carbohydrates, amino acids, organic acids, flavonoids, and phenolic compounds were identified to have significantly lower concentrations under the warming treatment than those under the control treatment. These results suggested that moisture stress under the warming treatment may drive C deficiency and metabolic restriction in plants. Conclusions: Under the warming condition, <i>C. lanceolata</i> changed its energy utilization strategy and invested more resources to produce macromolecular compounds for protecting against heat stress. Warming in sub-tropical forests alters plant chemical properties, and thus may have an important consequence for nutrient cycling and soil C sequestration.
|
|---|
