College of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, 621010, Sichuan, PR China; College of Architecture and Environment, Sichuan University, Chengdu, 610065, Sichuan, PR China.
College of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, 621010, Sichuan, PR China.
Chemosphere. 2020 Mar;242:125112. doi: 10.1016/j.chemosphere.2019.125112. Epub 2019 Oct 22.
This investigation was made to examine the role of indole-3-acetic acid (IAA), gibberellin A3 (GA), 6-Benzylaminopurine (6-BA), and 24-epibrassinolide (EBL) in improving stress tolerance and phytoremediation of the cadmium (Cd) and uranium (U) by mustard (Brassica juncea L.). The optimum concentrations of IAA, GA, 6-BA, and EBL were determined based on plant biomass production, metal uptake, translocation, and removal efficiency. The biomass and total chlorophyll content decreased under Cd and U stress. Nevertheless, the application of IAA, GA, and 6-BA significantly (p < 0.05) increased the growth and total chlorophyll content of mustard. The malondialdehyde (MDA) and HO content of mustard were enhanced under Cd and U stress, but they were significantly (p < 0.05) decreased in plant growth regulators (PGRs) treatments (except for EBL). PGRs treatments increased activities of antioxidant enzymes such as superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase, thus reducing the oxidative stress. Furthermore, the shoot uptake of Cd and U of IAA and EBL treatments was significantly (p < 0.05) higher than that of other treatments. IAA and EBL also have more significant effects on the translocation and remediation of Cd and U compared to GA and 6-BA. The removal efficiency of Cd and U reached the maximum in the 500 mg L IAA treatment, which was 330.77% and 118.61% greater than that in the control (CK), respectively. These results suggested that PGRs could improve the stress tolerance and efficiency of phytoremediation using B. juncea in Cd- and U- contaminated soils.
本研究旨在探讨吲哚-3-乙酸（IAA）、赤霉素 A3（GA）、6-苄氨基嘌呤（6-BA）和 24-表油菜素内酯（EBL）在提高芥菜（Brassica juncea L.）对镉（Cd）和铀（U）的胁迫耐受性和植物修复中的作用。基于植物生物量生产、金属吸收、转运和去除效率，确定了 IAA、GA、6-BA 和 EBL 的最佳浓度。在 Cd 和 U 胁迫下，生物量和总叶绿素含量下降。然而，IAA、GA 和 6-BA 的应用显著（p < 0.05）增加了芥菜的生长和总叶绿素含量。丙二醛（MDA）和 HO 的含量在 Cd 和 U 胁迫下增加，但在植物生长调节剂（PGRs）处理下（EBL 除外）显著（p < 0.05）降低。PGRs 处理增加了超氧化物歧化酶、过氧化物酶、过氧化氢酶和抗坏血酸过氧化物酶等抗氧化酶的活性，从而减轻了氧化应激。此外，IAA 和 EBL 处理对 Cd 和 U 的茎部吸收明显（p < 0.05）高于其他处理。与 GA 和 6-BA 相比，IAA 和 EBL 对 Cd 和 U 的转运和修复也有更显著的影响。在 500mg/L IAA 处理下，Cd 和 U 的去除效率达到最大值，分别比对照（CK）提高了 330.77%和 118.61%。这些结果表明，PGRs 可以提高芥菜在 Cd 和 U 污染土壤中的胁迫耐受性和植物修复效率。
