Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China.
Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China.
Chemosphere. 2023 Aug;333:138902. doi: 10.1016/j.chemosphere.2023.138902. Epub 2023 May 12.
Willows are promising candidates for phytoremediation, but the lead (Pb) phytoremediation potential of different willow ploidy and sex has not yet been exploited. In this study, the Pb uptake, translocation and detoxification capacities of hexaploid and diploid, female and male Salix rehderiana were investigated. The results showed that Pb treatment inhibited biomass accumulation and gas exchange, caused ultrastructural and oxidative damage, and induced antioxidant, phytohormonal and transcriptional regulation in S. rehderiana. Absorbed Pb was mainly accumulated in the roots with restricted root-to-shoot transport. Despite lower biomass, greater transpiration, phytohormonal and transcriptional regulation indicated that hexaploid S. rehderiana had higher tissue Pb concentration, total accumulated Pb amount (4.39 mg, 6.19 mg, 6.60 mg and 10.83 mg in diploid and hexaploid females and males, respectively) as well as bioconcentration factors and translocation factors (0.412, 0.593, 0.921 and 1.320 for bioconcentration factors in roots, and 0.029, 0.032, 0.035 and 0.047 for translocation factors in diploid and hexaploid females and males, respectively) than diploids. Higher soil urease and acid phosphatase activities also favored hexaploids to use more available N and P than diploids in Pb-contaminated soils. Additionally, hexaploid S. rehderiana had stronger antioxidant, phytohormonal and transcriptional responses, and displayed less morphological and ultrastructural damage than diploids after Pb treatment, suggesting that hexaploids have greater Pb uptake, translocation and detoxification capacities than diploids. Moreover, S. rehderiana males had greater Pb uptake and translocation abilities, as well as stronger antioxidant, phytohormonal, and transcriptional regulation mediated Pb detoxification capacities than females. Therefore, hexaploid S. rehderiana are superior to diploids, and males are better than females in Pb phytoremediation. This study provides novel and valuable insights for selecting better willow materials to mitigate Pb contamination.
柳树是植物修复的有前途的候选者，但不同倍性和性别的柳树对铅（Pb）的植物修复潜力尚未得到开发。在这项研究中，研究了六倍体和二倍体、雌性和雄性的雷氏柳对 Pb 的吸收、迁移和解毒能力。结果表明，Pb 处理抑制了雷氏柳的生物量积累和气体交换，造成了超微结构和氧化损伤，并诱导了抗氧化、植物激素和转录调控。吸收的 Pb 主要积累在根系中，限制了根到茎的运输。尽管六倍体雷氏柳的生物量较低，但蒸腾作用更大，植物激素和转录调控表明，六倍体雷氏柳的组织 Pb 浓度、总累积 Pb 量（二倍体和六倍体雌性和雄性分别为 4.39mg、6.19mg、6.60mg 和 10.83mg）以及生物浓缩因子和转运因子（根部的生物浓缩因子分别为 0.412、0.593、0.921 和 1.320，雌性和雄性的转运因子分别为 0.029、0.032、0.035 和 0.047）都高于二倍体。较高的土壤脲酶和酸性磷酸酶活性也有利于六倍体比二倍体在 Pb 污染土壤中利用更多的有效 N 和 P。此外，与二倍体相比，Pb 处理后，六倍体雷氏柳具有更强的抗氧化、植物激素和转录响应，形态和超微结构损伤更小，这表明六倍体比二倍体具有更强的 Pb 吸收、迁移和解毒能力。此外，雷氏柳雄性比雌性具有更大的 Pb 吸收和转运能力，以及更强的抗氧化、植物激素和转录调节介导的 Pb 解毒能力。因此，六倍体雷氏柳优于二倍体，雄性优于雌性，在 Pb 植物修复中更具优势。本研究为选择更好的柳树材料来减轻 Pb 污染提供了新的有价值的见解。
