Cadmium phytoextraction potential of king grass (Pennisetum sinese Roxb.) and responses of rhizosphere bacterial communities to a cadmium pollution gradient
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Screening for tolerant and high biomass producing plants is important for phytoextraction efforts in remediating agricultural soils contaminated by heavy metals. We carried out a greenhouse experiment involving a soil cadmium (Cd) concentration gradient (0.1, 0.5, 1, 2, 4, and 8 mg kg−1) to assess growth and phytoextraction capacity of king grass (Pennisetum sinese Roxb.) in soils contaminated by Cd and to explore changes in diversity and structure of rhizosphere soil bacterial communities in response to long-term Cd pollution. A significant positive relationship was observed between Cd concentrations in P. sinese stems, leaves, and roots and soil Cd concentration. The highest Cd concentrations in shoots and roots were 28.87 and 34.01 mg kg−1, respectively, at 8 mg kg−1of soil Cd supply. Total extraction amounts of Cd in P. sinese were 0.22–1.86 mg plant−1 corresponding to treatment with 0.5–8 mg kg−1 Cd. Most of the Cd was stored in shoots, and the largest accumulation was 1.56 mg plant−1 with 54.02 g dry shoot weight. After phytoextraction, changes in rhizobacterial community composition were found with different levels of Cd application, whereas there were no clear trends in diversity and richness. Results of this study show the feasibility of P. sinese in accumulating Cd and provide support for its application in remediation of soil moderately contaminated by Cd.
KeywordsCadmium Pennisetum sinese Roxb. Phytoextraction Soil bacterial community
We thank Prof. Li and his colleague for help with MiSeq sequencing.
This work was supported by the National Natural Science Foundation of China (41301576) and the Research Fund for science and technology project of Fujian (2017R1004-3). Part of this work was supported by Chengdu Institute of Biology, Chinese Academy of Science.
- Fierer N, Bradford MA, Jackson RB (2007) Toward an ecological classification of soil bacteria. Ecology 88:1353–1364Google Scholar
- Jackson ML (1985) Soil chemical analysis: advanced course, 2nd edn. University of Wisconsin, MadisonGoogle Scholar
- MEP, MLR (2014) The communique of national investigation of soil contamination. Ministry of environmental protection of the People’s Republic of China. Ministry of Land and Resources of the People’s Republic of China. http://www.mep.gov.cn/gkml/hbb/qt/201404/t20140417_270670.htm