Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha, 410083, China.
Center for Environment and Water Resources, College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, China; Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha, 410083, China.
J Environ Manage. 2024 Apr;356:120694. doi: 10.1016/j.jenvman.2024.120694. Epub 2024 Mar 23.
Ramie (Boehmeria nivea L.) is a promising phytoremediation candidate due to its high tolerance and enrichment capacity for antimony (Sb). However, challenges arise as Sb accumulated mainly in roots, complicating soil extraction. Under severe Sb contamination, the growth of ramie may be inhibited. Strategies are needed to enhance Sb accumulation in ramie's aboveground parts and improve tolerance to Sb stress. Considering the beneficial effects of selenium (Se) on plant growth and enhancing resistance to abiotic stresses, this study aimed to investigate the potential use of Se in enhancing Sb uptake by ramie. We investigated the effects of Se (0.5, 1, 2, 5, or 10 μM) on ramie growth, Sb uptake and speciation, antioxidant responses, and ionomic profiling in ramie under 10 mg/L of SbIII or antimonate (SbV) stresses. Results revealed that the addition of 0.5 μM Se significantly increased shoot biomass by 75.73% under SbIII stress but showed minimal effects on shoot and root length in both SbIII and SbV treatments. Under SbIII stress, 2 μM Se significantly enhanced Sb concentrations by 48.42% in roots and 62.88% in leaves. In the case of SbV exposure, 10 μM Se increased Sb content in roots by 42.57%, and 1 μM Se led to a 91.74% increase in leaves. The speciation analysis suggested that Se promoted the oxidation of SbIII to less toxic SbV to mitigate Sb toxicity. Additionally, Se addition effectively minimized the excess reactive oxygen species produced by Sb exposure, with the lowest malondialdehyde (MDA) content at 0.5 μM Se under SbIII and 2 μM Se under SbV, by activating antioxidant enzymes including superoxide dismutase, catalase, peroxidase, and glutathione peroxidase. Ionomic analysis revealed that Se helped in maintaining the homeostasis of certain nutrient elements, including magnesium, potassium (K), calcium (Ca), iron (Fe), and copper (Cu) in the SbIII-treated roots and K and manganese (Mg) in the SbV-treated roots. The results suggest that low concentrations of Se can be employed to enhance the phytoremediation of Sb-contaminated soils using ramie.
苎麻（Boehmeria nivea L.）由于其对锑（Sb）的高耐受性和富集能力，是一种很有前途的植物修复候选植物。然而，由于 Sb 主要积累在根部，这给土壤提取带来了困难，因此存在挑战。在严重的 Sb 污染下，苎麻的生长可能会受到抑制。需要采取策略来提高苎麻地上部分对 Sb 的积累能力，并提高对 Sb 胁迫的耐受性。考虑到硒（Se）对植物生长的有益影响以及增强对非生物胁迫的抗性，本研究旨在探讨 Se 在提高苎麻 Sb 吸收方面的潜在用途。我们研究了 Se（0.5、1、2、5 或 10 μM）对 10 mg/L SbIII 或锑酸盐（SbV）胁迫下苎麻生长、Sb 吸收和形态、抗氧化反应以及离子组学的影响。结果表明，在 SbIII 胁迫下，添加 0.5 μM Se 可使地上部生物量显著增加 75.73%，但对 SbIII 和 SbV 处理的地上部和根长几乎没有影响。在 SbIII 胁迫下，2 μM Se 可使根部 Sb 浓度显著增加 48.42%，叶片 Sb 浓度增加 62.88%。暴露于 SbV 时，10 μM Se 可使根部 Sb 含量增加 42.57%，1 μM Se 可使叶片 Sb 含量增加 91.74%。形态分析表明，Se 促进 SbIII 氧化为毒性较低的 SbV，从而减轻 Sb 的毒性。此外，添加 Se 可有效减少 Sb 暴露产生的过量活性氧，在 SbIII 下用 0.5 μM Se 和在 SbV 下用 2 μM Se 处理时，丙二醛（MDA）含量最低，同时激活了超氧化物歧化酶、过氧化氢酶、过氧化物酶和谷胱甘肽过氧化物酶等抗氧化酶。离子组学分析表明，Se 有助于维持 SbIII 处理的根部中某些营养元素（包括镁、钾（K）、钙（Ca）、铁（Fe）和铜（Cu））和 SbV 处理的根部中 K 和锰（Mg）的内稳性。结果表明，低浓度的 Se 可用于增强利用苎麻修复 Sb 污染土壤。
