大气CO_(2)浓度升高和土壤镉污染耦合对刺槐幼苗根系酚酸积累的影响

The Responses of Phenolic Acids in the Root of Robinia pseudoacacia L. Seedlings to the Combination of Elevated Atmospheric CO_(2) and Cadmium Exposure

根系酚酸类化合物对植物生长和根系抵抗不良环境具有重要作用,其合成易受环境因子如大气CO_(2)浓度升高和土壤重金属污染的影响.故以刺槐幼苗为材料,探讨了连续135 d大气CO_(2)浓度升高与镉(Cd)污染耦合下根系酚酸积累的特征.与单一Cd污染相比,大气CO_(2)浓度升高与土壤Cd污染耦合下,根系总酚酸、没食子酸、对羟基苯甲酸和对香豆酸的含量在幼苗生长90和135 d时显著升高(P<0.05),且没食子酸含量在幼苗生长45 d时亦显著增加(P<0.05),而绿原酸和咖啡酸含量在幼苗生长135 d时显著降低(P<0.05),阿魏酸含量在幼苗生长45和135 d显著增加(P<0.05),且CO_(2)、Cd和幼苗生长时间单一因子及交互作用对根系总酚酸和单体酚酸的积累影响显著.此外,皮尔逊相关分析表明,耦合条件下刺槐幼苗根系酚酸积累与根系Cd含量显著相关.

Phenolic acids in roots are important for plant growth and resistance of roots to adverse environments,which are affected by environment factors such as elevated atmospheric CO_(2) and heavy metal-polluted soils.The effect of 135-day elevated atmospheric CO_(2) on phenolic acid accumulation in roots of Robinia pseudoacacia L.seedlings exposed to cadmium(Cd)were explored in this study.Compared to Cd exposure alone,the contents of total phenolic acids,gallic acid,p-hydroxybenzoic acid,and p-coumaric acid in roots increased significantly(P<0.05)at 90 and135 days of seedling growth,gallic acid content also increased(P<0.05)at 45 d,chlorogenic acid and caffeic acid contents decreased(P<0.05)at 135 d,and ferulic acid content increased(P<0.05)at 45 and 135 d,under elevated CO_(2)+Cd exposure.The effects of CO_(2),Cd,growth time,and their interaction on total phenolic acids and phenolic acid monomers were significant.In addition,the accumulation of phenolic acids in roots of R.pseudoacacia seedlings was significantly related to Cd content in roots under the combined treatments according to the data on Pearson correlation analysis.