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Front. Environ. Sci. | doi: 10.3389/fenvs.2017.00079

Plant-mediated Changes in Soil N-cycling Genes during Revegetation of Copper Mine Tailings

Yang Li1,  Zhongjun Jia2,  Qingye Sun1*, Jianhua Cheng1, Yang Yang1, Jing Zhan1 and Dan Wang1
  • 1Anhui University, China
  • 2Institute of Soil Science (CAS), China

Nitrogen limitation represents a major bottleneck during the revegetation of mine tailings. However, controls over key nitrogen-cycling genes in rhizospheric soils under differential vegetation management remain poorly understood. The abundance and transcriptional activity of nitrogen-cycling genes and the enzymatic activity of nitrogen transformation are mediated differentially during revegetation of mine tailings by Imperata cylindrica and Chrysopogon zizanioides plants. Results showed that the highest total organic carbon (TOC), total nitrogen (TN) and NH4+-N contents were found in the rhizosphere of I. cylindrica. The nifH gene abundances differed between I. cylindrica and C. zizanioides, and were higher in I. cylindrica which demonstrated by 3.39-fold higher mRNA transcript abundance of the nifH gene and a 2.15-fold higher nitrogen fixation rate in the rhizosphere. In addition, C. zizanioides exhibited a 4.94-fold higher transcript abundance of the archaeal amoA gene and the highest nitrification rate (1.706±0.293 µg N-NO2- g-1 h-1) in the rhizosphere. In conclusion, I. cylindrica and C. zizanioides stimulated the abundances and activities of nifH gene and archaeal amoA gene, respectively. In addition, I. cylindrica appears to be capable of enhancing nitrogen fixation and exhibited accelerated nitrogen accumulation, which may be particularly useful for the rehabilitation of mine tailings.

Keywords: Mine tailings, revegetation, Nitrogen Cycle, rhizosphere, nifH gene

Received: 27 Aug 2017; Accepted: 09 Nov 2017.

Edited by:

Luiz Fernando W. Roesch, Federal University of Pampa, Brazil

Reviewed by:

Roberta Fulthorpe, University of Toronto Scarborough, Canada
Lucas William Mendes, University of São Paulo, Brazil  

Copyright: © 2017 Li, Jia, Sun, Cheng, Yang, Zhan and Wang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Prof. Qingye Sun, Anhui University, Hefei, China, sunqingye@ahu.edu.cn