College of Life Science and Technology, Honghe University, Mengzi, 661199, Yunnan, China.
Department of Horticulture and Landscape Architecture, Oklahoma State University, Stillwater, OK, USA.
Sci Rep. 2020 Dec 8;10(1):21439. doi: 10.1038/s41598-020-78593-8.
Heavy metal (HM) pollutants can cause serious phytotoxicity or oxidative stress in plants. Buddleja L., commonly known as "butterfly bushes", are frequently found growing on HM-contaminated land. However, to date, few studies have focused on the physiological and biochemical responses of Buddleja species to HM stress. In this study, potted seedlings of B. asiatica Lour. and B. macrostachya Wall. ex Benth. were subjected to various cadmium (Cd) concentrations (0, 25, 50, 100, and 200 mg kg) for 90 days. Both studied Buddleja species showed restricted Cd translocation capacity. Exposure to Cd, non-significant differences (p > 0.05) were observed, including quantum yield of photosystem II (PSII), effective quantum yield of PSII, photochemical quenching and non-photochemical quenching in both species between all studied Cd concentrations. Moreover, levels of cellular reactive oxygen species (ROS) significantly declined (p < 0.05) with low malondialdehyde concentrations. In B. asiatica, high superoxide dismutase and significantly enhanced (p < 0.05) peroxidase (POD) activity contributed greatly to the detoxification of excess ROS, while markedly enhanced POD activity was observed in B. macrostachya. Additionally, B. macrostachya showed higher membership function values than did B. asiatica. These results suggested that both Buddleja species exhibited high Cd resistance and acclimatization.
重金属（HM）污染物会对植物造成严重的植物毒性或氧化应激。醉鱼草属（Buddleja L.）通常被称为“蝴蝶灌木”，常生长在受 HM 污染的土地上。然而，迄今为止，很少有研究关注醉鱼草属物种对 HM 胁迫的生理和生化反应。在这项研究中，将 B. asiatica Lour. 和 B. macrostachya Wall. ex Benth. 的盆栽幼苗暴露于不同浓度的镉（Cd）（0、25、50、100 和 200mgkg）下 90 天。研究的两种醉鱼草属植物均表现出有限的 Cd 转运能力。在所有研究的 Cd 浓度下，两种植物的量子产率的光系统 II（PSII）、PSII 的有效量子产率、光化学猝灭和非光化学猝灭均无显著差异（p＞0.05）。此外，细胞内活性氧（ROS）水平显著下降（p＜0.05），同时丙二醛浓度较低。在 B. asiatica 中，高的超氧化物歧化酶和显著增强（p＜0.05）的过氧化物酶（POD）活性有助于解毒过量的 ROS，而 B. macrostachya 中观察到明显增强的 POD 活性。此外，B. macrostachya 的隶属函数值高于 B. asiatica。这些结果表明，两种醉鱼草属植物均表现出较高的 Cd 抗性和适应性。
