College of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, PR China; National Engineering Laboratory for Applied Technology of Forestry & Ecology in South China, Changsha 410004, PR China.
College of Life Science and Technology, Central South University of Forestry and Technology, Changsha 410004, PR China.
Ecotoxicol Environ Saf. 2018 Dec 15;165:654-661. doi: 10.1016/j.ecoenv.2018.08.107. Epub 2018 Sep 20.
Effective phytoremediation of manganese (Mn) requires the careful selection of a species that has a relatively high manganese tolerance. Exploring the physiological mechanisms related to Mn stress responses is crucial for identifying and employing species for Mn phytoremediation. Xanthium strumarium is a species that can accumulate high levels of Mn, thus it is a candidate species for Mn-phytoremediation. To reveal the tolerance mechanisms of this species to manage Mn stress, the morphological, physiological, and biochemical responses of seedlings grown in water cultures under six different Mn concentrations were analyzed. The results showed that X. strumarium can accumulate high levels of Mn, even as plant growth was inhibited by rising Mn concentrations. Malondialdehyde (MDA) content increased and catalase (CAT) activity decreased along with the increased Mn concentrations, while soluble protein and proline content, as well as the superoxide dismutase (SOD) and peroxidase (POD) enzymes, all increased initially and then declined. The highest value of POD, SOD, soluble protein and proline all occurred at 5000 µM of Mn stress, which means that X. strumarium can adapt to low concentration of Mn stress. The net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO concentration (Ci) and transpiration rate (Tr) decreased, and the stomatal limitation (Ls) increased in response to Mn stress. Furthermore, water use efficiency (WUE) and intrinsic water use efficiency (WUEi) increased first under low concentration of Mn, and then reduced as the concentration of Mn increased. The maximum quantum efficiency of PSII photochemistry (Fv/Fm), efficiency of excitation capture by open PSII reaction centers (Fv'/Fm'), electron transport rate (ETR) declined as Mn concentration increased. In conclusion, the above results showed that X. strumarium can be effectively used for phytoremediation of Mn-contaminated soils.
有效进行植物修复需要仔细选择具有较高耐锰性的物种。探索与锰胁迫响应相关的生理机制对于鉴定和利用植物修复锰的物种至关重要。苍耳是一种可以积累高水平锰的物种，因此是锰植物修复的候选物种。为了揭示该物种对锰胁迫的耐受机制，分析了在 6 种不同锰浓度下水培幼苗的形态、生理和生化响应。结果表明，苍耳可以积累高水平的锰，即使植物生长受到不断升高的锰浓度的抑制。随着锰浓度的增加，丙二醛（MDA）含量增加，过氧化氢酶（CAT）活性降低，而可溶性蛋白和脯氨酸含量以及超氧化物歧化酶（SOD）和过氧化物酶（POD）酶均先增加后减少。在 5000µM 的锰胁迫下，POD、SOD、可溶性蛋白和脯氨酸的最高值均出现，这意味着苍耳可以适应低浓度的锰胁迫。净光合速率（Pn）、气孔导度（Gs）、胞间 CO 浓度（Ci）和蒸腾速率（Tr）降低，气孔限制（Ls）随锰胁迫增加而增加。此外，在低浓度锰胁迫下，水分利用效率（WUE）和内在水分利用效率（WUEi）先增加，然后随着锰浓度的增加而降低。最大光化学量子产量（Fv/Fm）、开放 PSII 反应中心的激发捕获效率（Fv'/Fm'）和电子传递速率（ETR）随锰浓度增加而下降。综上所述，上述结果表明苍耳可有效用于修复受锰污染的土壤。
