College of Resources and Environment, Yunnan Agricultural University, Kunming, 650201, Yunnan Province, China.
College of Resources and Environment, Yunnan Agricultural University, Kunming, 650201, Yunnan Province, China.
Environ Res. 2022 Sep;212(Pt E):113594. doi: 10.1016/j.envres.2022.113594. Epub 2022 Jun 6.
Arbuscular mycorrhizal fungi (AMF) are ubiquitous in farmland. But the knowledge on AMF impact on lead (Pb) migration in farmland is limited. A field experiment was conducted in the rainy season (May-October) for two years in a Pb-polluted farmland. Benomyl was used to specifically suppress the native AMF growth in the farmland. The effect of benomyl-induced AMF suppression on the Pb uptake in maize, and Pb loss via surface runoff and interflows (20 cm and 40 cm depth) from the farmland was investigated. The benomyl significantly inhibited the AMF growth, resulting in decreases in the colonization rate, spore number, and contents of total and easily extractable glomalin-related soil protein (GRSP); and promoted the Pb migration into maize shoots and mainly enriched in leaves. The particulate Pb accounted for 83.2%-90.6% of Pb loss via surface runoff, while the proportion of particulate Pb loss via interflow was decreased and the proportion of dissolved Pb loss increased with the increase of soil depth. The AMF suppression led to a decrease in dissolved Pb concentration and loss, but an increase in particulate Pb concentration and loss, and enhanced the total Pb loss via surface runoff and interflows. Moreover, significant or very significant negative correlations were observed between the AMF colonization rate in roots with the Pb uptake in leaves, and the content of easily extractable GRSP with the particulate Pb loss. These results indicated the native AMF contributed to immobilizing Pb in soil and inhibited its migration to crops and the surrounding environment.
丛枝菌根真菌（AMF）在农田中普遍存在。但关于 AMF 对农田中铅（Pb）迁移影响的知识有限。在 Pb 污染的农田中进行了为期两年的雨季（5 月至 10 月）田间试验。苯并咪唑被用于专门抑制农田中本地 AMF 的生长。研究了苯并咪唑诱导的 AMF 抑制对玉米中 Pb 吸收以及通过农田表面径流和侧向流（20cm 和 40cm 深度）损失 Pb 的影响。苯并咪唑显著抑制了 AMF 的生长，导致其定殖率、孢子数以及总和易提取的球囊霉素相关土壤蛋白（GRSP）含量降低；并促进 Pb 向玉米茎叶迁移，主要富集在叶片中。颗粒态 Pb 占表面径流损失 Pb 的 83.2%-90.6%，而侧向流损失中颗粒态 Pb 的比例减少，溶解态 Pb 的比例增加，且随土壤深度的增加而增加。AMF 抑制导致溶解态 Pb 浓度和损失减少，但颗粒态 Pb 浓度和损失增加，从而增强了通过表面径流和侧向流的总 Pb 损失。此外，根中 AMF 定殖率与叶片中 Pb 吸收之间，以及易提取的 GRSP 含量与颗粒态 Pb 损失之间存在显著或极显著的负相关关系。这些结果表明，本地 AMF 有助于固定土壤中的 Pb，抑制其向作物和周围环境迁移。
