Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
J Hazard Mater. 2024 Sep 15;477:135322. doi: 10.1016/j.jhazmat.2024.135322. Epub 2024 Jul 25.
Arsenic-hyperaccumulator Pteris vittata exhibits remarkable absorption ability for chromium (Cr) while beneficial element selenium (Se) helps to reduce Cr-induced stress in plants. However, the effects of Se on the Cr uptake and the associated mechanisms in P. vittata are unclear, which were investigated in this study. P. vittata plants were grown for 14 days in 0.2-strength Hoagland solution containing 10 (Cr) or 100 μM (Cr) chromate (CrVI) and 1 μM selenate (Se). The plant biomass, malondialdehyde contents, total Cr and Se contents, Cr speciation, expression of genes associated with Cr uptake, and Cr subcellular distribution in P. vittata were determined. P. vittata effectively accumulated Cr by concentrating 96-99% in the roots under Cr treatment. Further, Se substantially increased its Cr contents by 98% to 11,596 mg kg in the roots, which may result from Se's role in reducing its oxidative stress as supported by 27-62% reduction in the malondialdehyde contents. Though supplied with CrVI, up to 98% of the Cr in the roots was reduced to insoluble chromite (CrIII), with 83-89% being distributed on root cell walls. Neither Cr nor Se upregulated the expression of sulfate transporters PvSultr1;1-1;2 or phosphate transporter PvPht1;4, indicating their limited role in Cr uptake. P. vittata effectively accumulates Cr in the roots mainly as CrIII on cell walls and Se effectively enhances its Cr uptake by reducing its oxidative stress. Our study suggests that Se can be used to enhance P. vittata Cr uptake and reduce its oxidative stress, which may have application in phytostabilization of Cr-contaminated soils.
砷超富集植物蜈蚣草对铬（Cr）具有显著的吸收能力，而有益元素硒（Se）有助于降低植物中 Cr 诱导的胁迫。然而，Se 对蜈蚣草中 Cr 吸收的影响及其相关机制尚不清楚，本研究对此进行了探讨。将蜈蚣草植株在含有 10（Cr）或 100 μM（Cr）铬酸盐（CrVI）和 1 μM 硒酸盐（Se）的 0.2 倍 Hoagland 溶液中培养 14 天。测定了蜈蚣草的生物量、丙二醛含量、总 Cr 和 Se 含量、Cr 形态、与 Cr 吸收相关基因的表达以及 Cr 的亚细胞分布。Cr 处理下，蜈蚣草根中 Cr 浓缩 96-99%，有效地积累了 Cr。此外，Se 使 Cr 含量增加了 98%至 11596mgkg，这可能是由于 Se 减轻了氧化应激，丙二醛含量降低了 27-62%。尽管提供了 CrVI，但根中高达 98%的 Cr 被还原为不溶性铬铁矿（CrIII），其中 83-89%分布在根细胞壁上。Cr 和 Se 均未上调硫酸盐转运蛋白 PvSultr1;1-1;2 或磷酸盐转运蛋白 PvPht1;4 的表达，表明它们在 Cr 吸收中的作用有限。蜈蚣草主要通过将 Cr 有效积累在细胞壁上的 CrIII 来积累 Cr，而 Se 通过降低氧化应激来有效增强其 Cr 吸收。本研究表明，Se 可用于增强蜈蚣草对 Cr 的吸收并降低其氧化应激，这可能在 Cr 污染土壤的植物稳定化中具有应用价值。
