Zhang Haoqiang, Ren Wei, Zheng Yaru, Li Yanpeng, Zhu Manzhe, Tang Ming
College of Forestry, Northwest A&F University, Yangling 712100, China.
State Key Laboratory of Conservation and Utilization of Subtropical Agro-Bioresources, Lingnan Guangdong Laboratory of Modern Agriculture, Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642, China.
Microorganisms. 2021 Jun 2;9(6):1203. doi: 10.3390/microorganisms9061203.
Arbuscular mycorrhizal (AM) fungi establish symbiosis and improve the lead (Pb) tolerance of host plants. The AM plants accumulate more Pb in roots than their non-mycorrhizal counterparts. However, the direct and long-term impact of AM fungi on plant Pb uptake has been rarely reported. In this study, AM fungus () colonized and non-colonized roots of were separated by a split-root system, and their differences in responding to Pb application were compared. The shoot biomass accumulation and transpiration were increased after inoculation, whereas the biomass of both colonized and non-colonized roots was decreased. Lead application in the non-colonized root compartment increased the colonization rate and up-regulated the relative expressions of and in the colonized root compartments. inoculation increased Pb uptake in both colonized and non-colonized roots, and transferred Pb to the colonized root segment. The Pb transferred through the colonized root segment had low mobility and might be sequestrated and compartmented in the root by The Pb uptake of roots might follow water flow, which is facilitated by MtPIP2. The quantification of Pb transfer via the mycorrhizal pathway and the involvement of MtPIP2 deserve further study.
丛枝菌根（AM）真菌可建立共生关系并提高宿主植物对铅（Pb）的耐受性。与非菌根植物相比，AM植物根系积累的铅更多。然而，AM真菌对植物吸收铅的直接和长期影响鲜有报道。在本研究中，利用分根系统将AM真菌（）定殖和未定殖的根系分开，并比较它们对施加铅的反应差异。接种后地上部生物量积累和蒸腾作用增加，而定殖和未定殖根系的生物量均下降。在未定殖的根区施加铅增加了定殖率，并上调了定殖根区和的相对表达。接种增加了定殖和未定殖根系对铅的吸收，并且将铅转运到定殖根段。通过定殖根段转运的铅移动性较低，可能被菌根固定并分隔在根部。根系对铅的吸收可能遵循水流，而这由MtPIP2促进。通过菌根途径转运铅的定量分析以及MtPIP2的作用值得进一步研究。
