Yang Qing, Xie Junting, Liu Huijun, Fang Zhiguo
College of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, China.
Environ Sci Pollut Res Int. 2022 Nov;29(51):76766-76781. doi: 10.1007/s11356-022-20686-0. Epub 2022 Jun 7.
Enhancing the uptake and enrichment of heavy metals in plants is one of the important means to strengthen phytoremediation. In the present study, citric acid (CA), tartaric acid (TA), and malic acid (MA) were applied to enhance phytoremediation by Bidens pilosa L. in Cd-contaminated soil. The results showed that by the addition of appropriate concentrations of CA, TA, and MA, the values of the bioconcentration factor increased by 77.98%, 78.33%, and 64.49%, respectively, the translocation factor values increased by 16.45%, 12.61%, and 5.73%, respectively, and the values of the phytoextraction rates increased by 169.21%, 71.28%, and 63.11%, respectively. The minimum fluorescence values of leaves decreased by 31.62%, 0.28%, and 17.95%, while the potential efficiency of the PSII values of leaves increased 117.87%, 2.25%, and 13.18%, respectively, when CA, TA, and MA with suitable concentration were added. Redundancy analysis showed that CA and MA in plants were significantly positively correlated with plant growth, photosynthesis, and other indicators, whereas TA showed a negative correlation with most indicators. Moreover, CA addition could significantly increase the abundances of Azotobacter, Pseudomonas, and other growth-promoting bacteria, and the abundance values of Actinophytocola and Ensifer were improved in TA treatments. Therefore, our results demonstrated that low-molecular-weight organic acids could enhance phytoremediation, and exogenous CA could significantly improve the phytoremediation of Cd-contaminated soil by Bidens pilosa L.
提高植物对重金属的吸收和富集是强化植物修复的重要手段之一。在本研究中，应用柠檬酸（CA）、酒石酸（TA）和苹果酸（MA）来增强三叶鬼针草对镉污染土壤的植物修复作用。结果表明，添加适当浓度的CA、TA和MA后，生物富集系数值分别增加了77.98%、78.33%和64.49%，转运系数值分别增加了16.45%、12.61%和5.73%，植物提取率值分别增加了169.21%、71.28%和63.11%。添加适宜浓度的CA、TA和MA时，叶片的最小荧光值分别降低了31.62%、0.28%和17.95%，而叶片PSII的潜在效率值分别提高了117.87%、2.25%和13.18%。冗余分析表明，植物体内的CA和MA与植物生长、光合作用等指标显著正相关，而TA与大多数指标呈负相关。此外，添加CA可显著增加固氮菌、假单胞菌等促生长细菌的丰度，TA处理提高了植生放线菌和根瘤菌的丰度值。因此，我们的结果表明低分子量有机酸可增强植物修复作用，外源CA可显著提高三叶鬼针草对镉污染土壤的植物修复效果。
