Plant-Mediated Changes in Soil N-Cycling Genes during Revegetation of Copper Mine Tailings

Abstract

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 NH + 4 -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-NO − 2 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.

Reverse transcriptase enzyme and priming strategy affect quantification and diversity of environmental transcripts

“…In environmental microbiology it is an invaluable approach to further link microbial activity, via gene expression, to microbial and ecosystem processes, compared to DNA approaches alone (Smith and Osborn, ; Saleh‐Lakha et al ., ; Gadkar and Filion, ). As a result the approach has been used to quantify transcripts to distinguish different pathways of the nitrogen cycle in sediments (Smith et al ., ; Santoro et al ., ; Zheng et al ., ; Damashek et al ., ; Duff et al ., ; Santos et al ., ; Zhang et al ., ), soil (Leininger et al ., ; Graham et al ., ; Wang et al ., ; Li et al ., ; Pierre et al ., ), water column (Santoro et al ., ; Kapoor et al ., ; Tolar et al ., ; Posman et al ., ; Feng et al ., ; Gonçalves et al ., ; Liu et al ., ; Christiansen et al ., ) and other microbial processes including water treatment (Botes et al ., ; Gadkar and Filion, ; Wang et al ., ; Pelissari et al ., , ) and bioremediation (Yergeau et al ., ; Marzorati et al ., 2010; Gadkar and Filion, ). In addition to this, cDNA from mRNA or rRNA can undergo PCR for amplicon sequencing to reveal actively transcribing organisms within the environment (Duff et al ., ; Zhang et al ., ; Cholet et al ., ).…”

Novel phosphate-solubilizing bacteria enhance soil phosphorus cycling following ecological restoration of land degraded by mining

“…Moreover, a These authors contributed equally: Jie-Liang Liang, Jun Liu, Pu Jia thorough understanding of soil P cycling during the ecological restoration of such ecosystems will inform efforts to mitigate P limitation in terrestrial ecosystems [5,9]. However, most studies on soil nutrient cycling during the restoration of heavily degraded mined lands have focused almost exclusively on N [14][15][16], leaving the impacts of ecological restoration on soil P cycling largely unknown. More surprisingly, even in the wider context of degraded lands, little attention has been paid to soil P cycling following such restoration efforts.…”

Under the Christmas Tree: Belowground Bacterial Associations With Abies nordmanniana Across Production Systems and Plant Development

“…Plant development is another important factor shaping the rhizosphere microbial communities of annual plants under both field and greenhouse conditions (Houlden et al, 2008;Micallef et al, 2009;Chaparro et al, 2014;Marques et al, 2014;Na et al, 2017Na et al, , 2019. The changes in rhizosphere microbial community composition with annual plant development stage are probably due to changed composition of root exudates, which can also influence the N-cycling microorganisms in the rhizosphere (Henry et al, 2008;Li et al, 2017) and alter the relative abundance of N-cycling genes (Hai et al, 2009). For long-lived host plants as the tree crops, more stable interactions may be established with their associated microbiota (Mercado-Blanco et al, 2018).…”