College of Architecture and Environment, Sichuan University, Chengdu, 610065, Sichuan, China; College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, Gansu, China.
College of Architecture and Environment, Sichuan University, Chengdu, 610065, Sichuan, China.
Ecotoxicol Environ Saf. 2021 Jan 1;207:111297. doi: 10.1016/j.ecoenv.2020.111297. Epub 2020 Sep 16.
The metal tolerance mechanism of plants is of great importance to explore the plant-based clean-up of environmental substrata contaminated by heavy metals. Indoor experiment of tobacco (Nicotiana tabacum L.) seedlings growing hydroponically in nutrient solution containing 0, 0.1, 0.5, 2.0, and 4.0 mg L V was conducted. The results indicated that plant overall growth performance was significantly affected at ≥ 2.0 mg L V. Oxidative stress degree as indicated by foliar O· and HO content intensified markedly at ≥ 0.5 mg L V treatments. In response, the plant activated its enzyme and non-enzyme protecting mechanism to cope with oxidative stress inflicted by vanadium. The activities of antioxidant enzymes, including SOD, POD, CAT, APX, and the concentration of non-enzyme antioxidants, e.g., AsA and GSH were all conspicuously (p < 0.5 or p < 0.1) enhanced at ≥ 0.5 mg L V treatments. Vanadium accumulated in leaves, stems, and roots increased with increasing vanadium level. The majority of the absorbed vanadium retained in plant root, and minor portions were transferred to aerial parts. Vanadium concentration in plant tissues ordered as root ˃ stem ˃ leaf. Translocation factors (TF) in vanadium-treated tobaccos (TF « 1) were significantly lower than that of control (TF ˃ 1). In conclusion, although vanadium at ≥ 2.0 mg L inhibited plant growth, tobacco exhibited a relatively good vanadium tolerance through self-adaptive regulation and has the potential as a phytostabilizer in decontaminating the environment contaminated by vanadium.
采用营养液水培的方法，研究了不同浓度（0、0.1、0.5、2.0 和 4.0mg·L-1）五氧化二钒（V）处理对烟草（Nicotiana tabacum L.）幼苗生长的影响。结果表明，V 浓度≥2.0mg·L-1时显著抑制了烟草幼苗的整体生长。当 V 浓度≥0.5mg·L-1时，叶片中 O·和 HO 的含量显著增加，表明植物的氧化应激程度加剧。为应对 V 诱导的氧化胁迫，植物激活了抗氧化酶和非酶保护机制。抗氧化酶活性，如 SOD、POD、CAT、APX 以及非酶抗氧化剂如 AsA 和 GSH 的浓度均在 V 浓度≥0.5mg·L-1时显著增加（p<0.5 或 p<0.1）。V 主要积累在叶片、茎和根中，且随 V 浓度的增加而增加。植物根系是 V 的主要蓄积部位，向地上部分的转移量较少。各组织中 V 的含量顺序为根＞茎＞叶。处理组烟草的转运系数（TF）均小于对照（TF<1）。综上，虽然 V 浓度≥2.0mg·L-1 抑制了烟草的生长，但烟草通过自身的适应性调节表现出较好的 V 耐性，有望成为一种修复 V 污染环境的植物稳定剂。
