Inoculation of Sinorhizobium saheli YH1 Leads to Reduced Metal Uptake for Leucaena leucocephala Grown in Mine Tailings and Metal-Polluted Soils

Frontiers in Microbiology

卷:9

Likou Zou¹  Lanfang Hu¹  Yunfu Gu¹  Yu Zhang¹  Menggen Ma¹  Xiumei Yu¹  Quanju Xiang¹  Xiaoping Zhang¹  Yanmei Li¹  Qiang Chen¹  Ke Zhao¹  Xia Kang²  Jinsan Kang³  Yongliang Cui⁴  Weiguo Tu⁴  Qiongyao Wang⁴ 

[1] College of Resources, Sichuan Agricultural University, Chengdu, China;

[2] Geomicrobiology Group, School of Life Sciences, University of Dundee, Dundee, United Kingdom;

[3] Sichuan Earthquake Administration, Chengdu, China;

[4] Sichuan Provincial Academy of Natural Resource and Sciences, Chengdu, China;

关键词: mine tailings;    heavy metals;    Leucaena leucocephala;    Sinorhizobium;    phytoremediation;   

DOI  :  10.3389/fmicb.2018.01853

来源: DOAJ

【 摘 要 】

Metalliferous mine tailings have a negative impact on the soil environment near mining areas and render cultivable lands infertile. Phytoremediation involving the synergism of legume and rhizobia provides a useful technique in tackling this issue with cost-effective, environmentally friendly, and easy-to-use features under adverse soil conditions. Leucaena leucocephala has been found to build symbiotic relationships with native rhizobia in the iron-vanadium-titanium oxide (V-Ti magnetite) mine tailing soil. Rhizobia YH1, isolated from the root nodules of L. leucocephala, was classified as Sinorhizobium saheli according to similarity and phylogenetic analyses of 16S rRNA, housekeeping and nitrogen fixation genes. Besides nitrogen fixation, S. saheli YH1 also showed capabilities to produce indole-acetic acid (IAA) (166.77 ± 2.03 mg l−1) and solubilize phosphate (104.41 ± 7.48 mg l−1). Pot culture experiments showed that strain YH1 increased the biomass, plant height and root length of L. leucocephala by 67.2, 39.5 and 27.2% respectively. There was also an average increase in plant N (10.0%), P (112.2%) and K (25.0%) contents compared to inoculation-free control. The inoculation of YH1 not only reduced the uptake of all metals by L. leucocephala in the mine tailings, but also resulted in decreased uptake of Cd by up to 79.9% and Mn by up to 67.6% for plants grown in soils contaminated with Cd/Mn. It was concluded that S. saheli YH1 possessed multiple beneficial effects on L. leucocephala grown in metalliferous soils. Our findings highlight the role of S. saheli YH1 in improving plant health of L. leucocephala by reducing metal uptake by plants grown in heavy metal-polluted soils. We also suggest the idea of using L. leucocephala-S. saheli association for phytoremediation and revegetation of V-Ti mine tailings and soils polluted with Cd or Mn.

【 授权许可】

Unknown