Wu Juanzi, Qian Chen, Liu Zhiwei, Zhong Xiaoxian
National Forage Breeding Innovation Base (JAAS), Nanjing, People's Republic of China.
Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, People's Republic of China.
Environ Sci Pollut Res Int. 2023 Feb;30(10):26208-26217. doi: 10.1007/s11356-022-23848-2. Epub 2022 Nov 10.
Cadmium (Cd) contamination in soil is a global problem. Recently, phytoremediation with plants, possessing high biomass and moderate Cd enrichment ability, has received excessive attention as a cost-effective method for Cd remediation from the soil. In this study, the plant growth, physiological responses, Cd concentration, accumulation, and distribution of the C4 grass hybrid Pennisetum (HP) were studied in different levels of Cd-contaminated soil in a pot experiment. Furthermore, a field trial was also conducted to accurately assess its practical phytoremediation potential in natural Cd-contaminated fallow filed. The results showed that HP possessed effective antioxidant enzymes to scavenge ROS and strong physiological coordination in response to Cd stress. The HP had a considerable Cd enrichment ability, and the maximal Cd uptake of 1.08 mg plant was achieved at 60 mg kg Cd in the pot. The maximal concentration of Cd in the aboveground parts and roots of HP were 49.33 mg kg and 103.33 mg kg, respectively, when soil Cd was 70 mg kg in the pot. The bioconcentration factor (BCF) of Cd in the aboveground parts was less than 1, while the BCF in the root was greater than 1, and the translocation factor (TF) was less than 0.5 in all Cd treatment groups. A total of 46.89-65.46% absorbed Cd stored in the aboveground parts in the pot. The Cd concentration in roots of HP was significantly higher compared to those in leaves and stems, and all BCFs were greater than 1.5 in a lightly Cd-contaminated field (0.35 mg kg). Furthermore, HP had high aboveground dry biomass up to 54.63 t ha and accumulated 16.13 g ha Cd in its aboveground parts in the field, which was accounted for about 91.54% of the total Cd extracted by the plant. The soil Cd concentration was reduced by 60.00% after planting HP. Our results suggest that HP is a potential phytoextractor for Cd in lightly Cd-contaminated soil as well as a phytostabilizer under strong Cd stress in the pot.
土壤中的镉（Cd）污染是一个全球性问题。近年来，利用生物量高且镉富集能力适中的植物进行植物修复，作为一种从土壤中修复镉的经济有效方法受到了广泛关注。在本研究中，通过盆栽试验研究了C4禾本科杂交狼尾草（HP）在不同镉污染水平土壤中的生长、生理响应、镉浓度、积累和分布情况。此外，还进行了田间试验，以准确评估其在天然镉污染休耕地上的实际植物修复潜力。结果表明，HP拥有有效的抗氧化酶来清除活性氧，并在应对镉胁迫时具有强大的生理协调性。HP具有相当可观的镉富集能力，在盆栽试验中，土壤镉含量为60 mg kg时，植物最大吸镉量达到1.08 mg/株。盆栽试验中，当土壤镉含量为70 mg kg时，HP地上部分和根部的镉最大浓度分别为49.33 mg kg和103.33 mg kg。所有镉处理组地上部分的镉生物富集系数（BCF）均小于1，而根部的BCF大于1，转运系数（TF）小于0.5。盆栽试验中，HP吸收的镉总量的46.89% - 65.46%储存在地上部分。在轻度镉污染田（0.35 mg kg）中，HP根部的镉浓度显著高于叶片和茎部，且所有BCF均大于1.5。此外，HP地上部干生物量高达54.63 t/ha，田间地上部分积累了16.13 g/ha的镉，约占植物提取总镉量 的91.54%。种植HP后，土壤镉浓度降低了60.00%。我们的研究结果表明，HP是轻度镉污染土壤中镉的潜在植物提取剂，也是盆栽试验中强镉胁迫下的植物稳定器。
