Growth under elevated air temperature alters secondary metabolites in Robinia pseudoacacia L. seedlings in Cd- and Pb-contaminated soils

• Published in: The Science of the total environment Vol. 565; pp. 586 - 594
• Main Authors: Zhao, Y.H., Jia, X., Wang, W.K., Liu, T., Huang, S.P., Yang, M.Y.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.09.2016
• Subjects: Cadmium - metabolism; Cd-contaminated soils; Elevated air temperature; Global Warming; Lead - metabolism; Pb-contaminated soils; Plant Leaves - growth & development; Plant Leaves - metabolism; Robinia - growth & development; Robinia - metabolism; Robinia pseudoacacia; Robinia pseudoacacia L. seedlings; Secondary metabolites; Soil Pollutants - metabolism; Temperature; Secondary metabolites; Robinia pseudoacacia L. seedlings; Elevated air temperature; Cd-contaminated soils; Pb-contaminated soils
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2016.05.058

Plant secondary metabolites play a pivotal role in growth regulation, antioxidant activity, pigment development, and other processes. As the global climate changes, increasing atmospheric temperatures and contamination of soil by heavy metals co-occur in natural ecosystems, which alters the pH of rhizosphere soil and influences the bioavailability and mobility of metals. Elevated temperatures in combination with heavy metals are expected to affect plant secondary metabolites, but this issue has not been extensively examined. Here, we investigated secondary metabolites in Robiniapseudoacacia seedlings exposed to elevated temperatures using a passive warming device in combination with Cd- and Pb-contaminated soils. Heavy metals significantly stimulated the accumulation of saponins, phenolic compounds, and flavonoids in leaves and stems; alkaloid compounds increased in leaves and decreased in stems, and condensed tannins fluctuated. Elevated temperatures, alone and in combination with Cd and Pb, caused increases in secondary metabolites in the plant tissues. Phenolic compounds showed the greatest changes among the secondary metabolites and significant interactive effects of temperature and metals were observed. These results suggest that slightly elevated temperature could enhance protective and defense mechanisms of Robinia pseudoacacia seedlings exposed to heavy metals by stimulating the production of secondary metabolites. [Display omitted] •Global warming and heavy metal-contaminated soils co-occur at present.•Both elevated air temperature and heavy metals could affect plant growth.•Elevated temperature enhanced the stress of heavy metals on R. pseudoacacia.•Elevated temperature stimulated secondary metabolite production under heavy metal.