The excessive use of rare earth elements (REEs) as micro-fertilizers is harmful to agricultural production and the environment. This study explored the potential application of carbon dots (CDs) to mitigate the effects of La contamination. The results indicate that the CDs based on citric acid (C-CDs) can adsorb La³⁺ in an aqueous solution system through surface carboxyl and pyrrolic-N. While no significant alteration in the total La content within mung bean seedlings was observed, the presence of C-CDs induced the conversion of La into an inactive form within the body and significantly affected the chemical form and distribution of La in the plant body. However, with increased concentrations, C-CDs do not effectively improve growth inhibition of the seedlings under La stress but exacerbate it. This may be relevant to the peroxidation damage and excess extracellular precipitates. RNA-seq results showed stronger cell wall-related synthesis under C-CD and La co-treatment than in La treatment, which indicated the important role of the cell wall in this process. Although many issues remain to be addressed, this study demonstrates that C-CDs possess distinct advantages in remediating soil La contamination without significantly impeding the plant's La absorption, thus exhibiting considerable potential for agricultural application.

中文翻译：

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碳点对 La3+ 的吸附行为及其对 La3+ 胁迫下绿豆幼苗生长的多重影响


过度使用稀土元素 （REE） 作为微肥料对农业生产和环境有害。本研究探讨了碳点 （CDs） 在减轻 La 污染影响方面的潜在应用。结果表明，基于柠檬酸的 CDs （C-CDs） 可以通过表面羧基和吡咯-N 吸附水溶液体系中的 La³⁺。虽然未观察到绿豆幼苗中总 La 含量的显着变化，但 C-CDs 的存在诱导 La 在体内转化为非活性形式，并显着影响 La 在植物体内的化学形式和分布。然而，随着浓度的增加，C-CDs 在 La 胁迫下并不能有效改善幼苗的生长抑制，反而会加剧这种抑制。这可能与过氧化损伤和过多的细胞外沉淀物有关。RNA-seq 结果显示，C-CD 和 La 共处理下细胞壁相关合成强于 La 处理，这表明细胞壁在此过程中起重要作用。尽管仍有许多问题有待解决，但本研究表明，C-CDs 在修复土壤 La 污染方面具有明显的优势，而不会显着阻碍植物对 La 的吸收，因此显示出相当大的农业应用潜力。