Kuang Qiqiang, Wu Yujie, Gao Yamin, An Tingting, Liu Shuo, Liang Liyan, Xu Bingcheng, Zhang Suiqi, Yu Min, Shabala Sergey, Chen Yinglong
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, and College of Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, and College of Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; School of Agriculture, Henan Institute of Science and Technology, Xinxiang, Henan 453003, China.
Ecotoxicol Environ Saf. 2025 Jan 1;289:117600. doi: 10.1016/j.ecoenv.2024.117600. Epub 2025 Jan 2.
Soil cadmium (Cd) pollution poses a significant environmental threat, impacting global food security and human health. Recent studies have highlighted the potential of arbuscular mycorrhizal (AM) fungi to protect crops from various heavy metal stresses, including Cd toxicity. To elucidate the tolerance mechanisms of maize in response to Cd toxicity under AM symbiosis, this study used two maize genotypes with contrasting Cd tolerance: Zhengdan958 (Cd-tolerant) and Zhongke11 (Cd-sensitive). Rhizobox experiments were conducted with and without AM inoculation, alongside Cd treatment. The results revealed that Cd stress severely impaired growth and root development in both genotypes. However, AM symbiosis significantly improved plant height, stem diameter, biomass, root morphology, photosynthetic capacity, nutrient uptake, antioxidant enzyme activity, root Cd content, and concentration, while also reducing lipid peroxidation and shoot Cd accumulation in both genotypes. Notably, AM symbiosis had a more pronounced effect on stem diameter (increased 55 %), root dry weight (118 %), root superoxide dismutase (42 %), and peroxidase activity (209 %), as well as shoot translocation factor (77 %) in Zhongke11 compared to Zhengdan958. Overall, AM symbiosis alleviated Cd toxicity in maize through multiple mechanisms, including enhanced photosynthesis, nutrient uptake, antioxidant defenses, and modulation of Cd transport and accumulation. This study provides valuable insights into the potential application of Cd-tolerant maize genotypes and AM symbiosis for managing Cd-contaminated soils.
土壤镉（Cd）污染对环境构成重大威胁，影响全球粮食安全和人类健康。最近的研究强调了丛枝菌根（AM）真菌在保护作物免受包括镉毒性在内的各种重金属胁迫方面的潜力。为了阐明玉米在AM共生条件下对镉毒性的耐受机制，本研究使用了两种镉耐受性不同的玉米基因型：郑单958（耐镉）和中科11（镉敏感）。在接种和未接种AM真菌的情况下进行了根箱试验，并设置了镉处理。结果表明，镉胁迫严重损害了两种基因型的生长和根系发育。然而，AM共生显著提高了两种基因型的株高、茎粗、生物量、根系形态、光合能力、养分吸收、抗氧化酶活性、根镉含量和浓度，同时还降低了脂质过氧化和地上部镉积累。值得注意的是，与郑单958相比，AM共生对中科11的茎粗（增加55%）、根干重（118%）、根超氧化物歧化酶（42%）、过氧化物酶活性（209%）以及地上部转运系数（77%）的影响更为显著。总体而言，AM共生通过多种机制减轻了玉米的镉毒性，包括增强光合作用、养分吸收、抗氧化防御以及调节镉的运输和积累。本研究为耐镉玉米基因型和AM共生在治理镉污染土壤方面的潜在应用提供了有价值的见解。
