丛枝菌根共生强化超富集植物龙葵提取土壤Cd的机制研究

重金属镉（Cd）是影响我国耕地土壤环境质量的首要无机污染物，严重影响土地安全利用和人体健康。我们前期研究表明丛枝菌根真菌（AMF）显著促进超富集植物龙葵对Cd的积累，但菌根如何增强龙葵重金属Cd提取的作用机制仍不清楚。本项目以菌根促进龙葵Cd积累的菌根际调控机制为研究主线，通过稳定同位素与转录组分析，明确AMF提高该共生体系对Cd获取的直接（吸收）与间接（促生）作用，并定量菌根吸收途径对Cd吸收的贡献。同时，通过多区室盆栽培养、X射线荧光光谱法以及高通量测序平台，系统深入分析龙葵-AMF共生体系根土界面关键环境因子变化对重金属Cd活化的作用，从根际与菌丝际理化参数、生物学特征及其对微生物“招募”互作的差异出发，揭示菌根强化超富集植物对重金属提取的菌根际调控过程。项目研究可为植物-微生物互作增强超富集植物修复能力，实现重金属污染的绿色修复提供理论依据。

Cadmium (Cd) is the primary inorganic pollutant that affects the cultivated land quality in China, and seriously affects the safe use of soil and human health. Our previous studies showed that arbuscular mycorrhizal fungi (AMF) significantly promoted Cd accumulation in the Cd-hyperaccumulator Solanum nigrum (S. nigrum), but the related mechanism is still unclear. This project focuses on the mycorrhizal regulation mechanism on promoting Cd accumulation in S. nigrum. Based on the previous work, the Cd stable isotope and the transcriptome technique will be used to prove the direct and indirect effects, and the contribution rate of the mycorrhizal absorption pathway to Cd accumulation in S. nigrum. And the effects of key environmental factors at the root-soil interface on the Cd activation in this symbiosis system will be identified by the multi-compartment pot culture system, the X-ray fluorescence spectrometry, and the high-throughput sequencing technique. The rhizosphere and mycelial mechanism regulating the Cd uptake of the S. nigrum-AMF system will be revealed, by analyzing the physical and chemical parameters, the biological characteristics of the rhizosphere and mycelium, and the difference in the microbial interactions. This project will provide a scientific basis for plant-microbe interaction to enhance the remediation ability of hyperaccumulators, and realize the green remediation of the heavy metal-contaminated soil.