Shanghai High School International Division (SHSID), Shanghai, China.
PLoS One. 2021 Sep 7;16(9):e0257172. doi: 10.1371/journal.pone.0257172. eCollection 2021.
As an essential element, zinc (Zn) can improve or inhibit the growth of plants depending on its concentrations. In this study, the effects of 24-Epibrassinolide (EBR), one well-known steroid phytohormone regulating plant growth and alleviating abiotic stress damage, on morphological parameters and antioxidant capacities of Sedum lineare were investigated under different Zn doses. Compared to plants only exposed to Zn, simultaneously foliar application of 0.75 μM EBR significantly improved multiple morphological characteristics and such growth-improving effects were more significant at high Zn concentrations. At a detrimental 800 μM Zn, EBR benefitted plant growth most prominently, as shown by that the stem length, fresh weight and internode length were increased by 111%, 85% and 157%, respectively; than Zn solely treated plants. EBR spray also enhanced both the activities of antioxidant enzymes such as peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR), and the contents of antioxidative agents including ascorbic acid (AsA) and glutathione (GSH), which in turn decreased the accumulation of reactive oxygen species (ROS) and alleviated the lipid peroxidation in plants. Thus, by demonstrating that EBR could help S. lineare resist high-zinc stress through strengthening the antioxidant system, this work provided a new idea for expanding the planting range of Crassulaceae plants in heavy metal contaminated soil for phytoremediation purpose in the future.
作为一种必需元素，锌（Zn）的浓度会影响其对植物生长的促进或抑制作用。在这项研究中，研究了 24-表油菜素内酯（EBR）——一种调节植物生长和缓解非生物胁迫损伤的知名甾体植物激素，对不同锌剂量下Sedum lineare 形态参数和抗氧化能力的影响。与仅暴露于锌的植物相比，同时叶面喷施 0.75 μM EBR 显著改善了多种形态特征，并且在高锌浓度下，这种促进生长的效果更为显著。在 800 μM 的有害锌浓度下，EBR 对植物生长的促进作用最为显著，表现在茎长、鲜重和节间长度分别增加了 111%、85%和 157%；而单独用锌处理的植物。EBR 喷雾还增强了抗氧化酶的活性，如过氧化物酶（POD）、抗坏血酸过氧化物酶（APX）、谷胱甘肽还原酶（GR），以及抗氧化剂的含量，包括抗坏血酸（AsA）和谷胱甘肽（GSH），从而减少活性氧（ROS）的积累，减轻植物的脂质过氧化作用。因此，通过证明 EBR 可以通过加强抗氧化系统帮助 S. lineare 抵抗高锌胁迫，这项工作为未来扩大景天科植物在重金属污染土壤中的种植范围，用于植物修复提供了一个新的思路。
