He Ding, Guo Ting, Peng Chunqing, Li Jining, Wang Fenghe
School of Environment, Nanjing Normal University, Nanjing, Jiangsu, 210023, China.
School of Environment, Nanjing Normal University, Nanjing, Jiangsu, 210023, China; Key Laboratory for Soft Chemistry and Functional Materials of Ministry of Education, Nanjing University of Science and Technology, Nanjing, Jiangsu, 210094, China; Jiangsu Province Engineering Research Center of Environmental Risk Prevention and Emergency Response Technology, Nanjing, Jiangsu, 210023, China.
J Environ Manage. 2023 May 15;334:117259. doi: 10.1016/j.jenvman.2023.117259. Epub 2023 Feb 8.
The hormetic effect of rare earth elements (REEs) has been found in a variety of crops and has been promoting crop growth for decades. Spraying leaves with REEs can enhance the endocytosis of plant roots. The non-selectivity of endocytosis is conducive to the direct absorption of environmental pollutants. The hyperaccumulator Solanum nigrum L. (S. nigrum), as a plant with high biomass and heavy metal tolerance, is a good candidate for phytoremediation. La(III), as a typical light REE, also has an obvious hormetic effect on S. nigrum. At 10 μM La(III), the biomass of S. nigrum reached the maximum, which was 89% greater than the control, and La(III) concentration was much lower than the previously reported optimum of 56 μM for general plants. In the present study, enhanced endocytosis after foliar spraying of La(III) was firstly observed in the root cell of hyperaccumulation plants, and La(III) increased the biomass of S. nigrum by improving the photosynthetic system, and promoting nutrient uptake and root development. The antioxidant defense system improved by La(III) contributed to the tolerance of S. nigrum to heavy metals. Applying a reasonable range of La(III) is beneficial to improving S. nigrum growth and tolerance of heavy metals. Compared with spraying deionized water, the translocation factor and bioaccumulation factor value of S. nigrum to cadmium increased by 15% and 21% respectively when spraying 10 μM La(III). Our findings provide a reference for improving hyperaccumulator plant growth and biomass, which improves phytoremediation efficiency.
稀土元素（REEs）的 hormetic 效应已在多种作物中被发现，并且几十年来一直在促进作物生长。用稀土元素对叶片进行喷施可以增强植物根系的内吞作用。内吞作用的非选择性有利于环境污染物的直接吸收。超富集植物龙葵（Solanum nigrum L.）作为一种具有高生物量和重金属耐受性的植物，是植物修复的良好候选者。镧（III）作为一种典型的轻稀土元素，对龙葵也有明显的 hormetic 效应。在 10 μM 镧（III）处理下，龙葵的生物量达到最大值，比对照高出 89%，且镧（III）浓度远低于先前报道的一般植物的最佳浓度 56 μM。在本研究中，首次在超富集植物的根细胞中观察到叶面喷施镧（III）后内吞作用增强，镧（III）通过改善光合系统、促进养分吸收和根系发育来增加龙葵的生物量。镧（III）改善的抗氧化防御系统有助于龙葵对重金属的耐受性。施用合理范围的镧（III）有利于提高龙葵的生长和对重金属的耐受性。与喷施去离子水相比，喷施 10 μM 镧（III）时，龙葵对镉的转运系数和生物富集系数值分别增加了 15%和 21%。我们的研究结果为提高超富集植物的生长和生物量提供了参考，从而提高植物修复效率。
