Priming effects of nZVI on carbon sequestration and iron uptake are positively mediated by AM fungus in semiarid agricultural soils

Yu-Miao Yang; Minha Naseer; Ying Zhu; Bao-Zhong Wang; Song Wang; Yue Ma; Xiao-Lin Zhang; Xu-Zhe Zhao; Wen-Ying Wang; Shuang-Guo Zhu; Hong-Yan Tao; You-Cai Xiong

doi:10.1016/j.scitotenv.2023.163632

Priming effects of nZVI on carbon sequestration and iron uptake are positively mediated by AM fungus in semiarid agricultural soils

Sci Total Environ. 2023 Jul 15:882:163632. doi: 10.1016/j.scitotenv.2023.163632. Epub 2023 Apr 18.

Authors

Affiliations

¹ State Key Laboratory of Grassland Agroecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China.
² Institute of Biology, Gansu Academy of Sciences, Lanzhou 730000, China.
³ College of Life Science, China West Normal University, Nanchong 637009, China.
⁴ School of Life Sciences, Qinghai Normal University, Xining 810001, China.
⁵ State Key Laboratory of Grassland Agroecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China. Electronic address: beltroad@lzu.edu.cn.
⁶ State Key Laboratory of Grassland Agroecosystems, College of Ecology, Lanzhou University, Lanzhou 730000, China. Electronic address: xiongyc@lzu.edu.cn.

PMID: 37080320
DOI: 10.1016/j.scitotenv.2023.163632

Abstract

We investigated the priming effect of nanoscale zero-valent iron (nZVI) on carbon sink and iron uptake, and the possible mediation by AMF (arbuscular mycorrhizal fungi, Funneliformis mosseae) in semiarid agricultural soils. Maize seed dressings comprised of three nZVI concentrations of 0, 1, 2 g·kg^-1 and was tested with and without AMF inoculation under high and low soil moistures, respectively. The ICP-OES observations indicated that both low dose of nZVI (1 g·kg^-1) and high dose of nZVI (2 g·kg^-1) significantly increased the iron concentrations in roots (L: 54.5-109.8 %; H: 119.1-245.4 %) and shoots (L: 40.8-78.9 %; H: 81.1-99.4 %). Importantly, the absorption and translocation rate of iron were substantially improved by AMF inoculation under the low-dose nZVI. Yet, the excess nanoparticles as a stress were efficiently relieved by rhizosphere hyphae, and the iron concentration in leaves and stems can maintain as high as about 300 mg·kg^-1 while the iron translocation efficiency was reduced. Moreover, next-generation sequencing confirmed that appropriate amount of nZVI clearly improved the rhizosphere colonization of Funneliformis mosseae (p < 0.001) and the development of soil fungal community. Soil observations further showed that the hyphae development and GRSP (glomalin-related soil protein) secretion were significantly promoted (p < 0.05), with the increased R_0.25 (< 0.25 mm) by 35.97-41.16 %. As a return, AMF and host plant turned to input more organic matter into soils for microbial growth and Fe uptake, and such interactions became more pronounced under drought stress. In contrast, high dose of nZVI (2 g·kg^-1) tended to agglomerate on the surface of hyphae and spores, causing severe deformation and inactivation of AMF symbionts. Therefore, the priming effects of nZVI on carbon sequestration and Fe uptake in agricultural soils were positively mediated by AMF via the feedback loop of the plant-soil-microbe system for enhanced adaptation to global climate change.

Keywords: Carbon sequestration; Fe uptake; Funneliformis mosseae; Nanoscale zero-valent iron (nZVI); Priming effect; Rhizosphere interaction.

MeSH terms

Carbon Sequestration
Iron* / metabolism
Mycorrhizae* / physiology
Plant Roots
Soil

Substances

Iron
Soil

Supplementary concepts

Funneliformis mosseae