Effects of CO2 application and endophytic bacterial inoculation on morphological properties, photosynthetic characteristics and cadmium uptake of two ecotypes of Sedum alfredii Hance
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Plant uptake of cadmium (Cd) is affected by soil and environmental conditions. In this study, hydroponic experiments were conducted to investigate the effects of elevated CO2 coupled with inoculated endophytic bacteria M002 on morphological properties, gas exchange, photosynthetic pigments, chlorophyll fluorescence, and Cd uptake of S. alfredii. The results showed that bio-fortification processes (elevated CO2 and/or inoculated with endophytic bacteria) significantly (p < 0.05) promoted growth patterns, improved photosynthetic characteristics and increased Cd tolerance of both ecotypes of S. alfredii, as compared to normal conditions. Net photosynthetic rate (Pn) in intact leaves of hyperaccumulating ecotype (HE) and non-hyperaccumulating ecotype (NHE) were increased by 73.93 and 32.90%, respectively at the low Cd (2 μM), 84.41 and 57.65%, respectively at the high Cd level (10 μM). Superposition treatment increased Cd concentration in shoots and roots of HE, by 50.87 and 82.12%, respectively at the low Cd and 46.75 and 88.92%, respectively at the high Cd level. Besides, superposition treatment declined Cd transfer factor of NHE, by 0.85% at non-Cd rate, 17.22% at the low Cd and 22.26% at the high Cd level. These results indicate that elevated CO2 coupled with endophytic bacterial inoculation may effectively improve phytoremediation efficiency of Cd-contaminated soils by hyperaccumulator, and alleviate Cd toxicity to non-hyperaccumulator ecotype of Sedum alfredii.
KeywordsCadmium uptake Elevated CO2 Endophyte Photosynthesis Sedum alfredii
This study was financially supported by the Key Projects from Ministry of Science and Technology of China (#2016YFD0800805), Zhejiang Provincial Science and Technology Bureau (#2015C02011-3; #2015C03020-2), Fundamental Research Funds for the Central Universities, and the Funding from Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health.
- Belimov AA, Hontzeas N, Safronova VI, Demchinskaya SV, Piluzza G, Bullitta S, Glick BR (2005) Cadmium-tolerant plant growth-promoting bacteria associated with the roots of Indian mustard (Brassica juncea L. Czern.). Soil Biol Biochem 37:241–250Google Scholar
- IPCC (2007) Climate change 2007: the physical science basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, New YorkGoogle Scholar
- Luo S, Chen L, Chen J, Xiao X, Xu T, Wan Y, Rao C, Liu C, Liu Y, Lai C, Zeng G (2011) Analysis and characterization of cultivable heavy metal resistant bacterial endophytes isolated from Cd-hyperaccumulator Solanum nigrum L. and their potential use for phytoremediation. Chemosphere 85:1130–1138CrossRefGoogle Scholar
- Tang L, Luo WJ, Chen WK, He ZL, Gurajala HK, Hamid Y, Deng MH, Yang XE (2017) Field crops (Ipomoea aquatica Forsk. and Brassica chinensis L.) for phytoremediation of cadmium and nitrate co-contaminated soils via rotation with Sedum alfredii Hance. Environ Sci Pollut Res 24:19293–19305CrossRefGoogle Scholar