Poly-γ-glutamic acid, a bio-chelator, alleviates the toxicity of Cd and Pb in the soil and promotes the establishment of healthy Cucumis sativus L. seedling
- 93 Downloads
Poly-γ-glutamic acid (γ-PGA) can be used as a chemical stabilizer to chelate heavy metals in polluted soils. We investigated the effects of γ-PGA on cucumber seedlings under Cd and Pb stresses. γ-PGA effectively reduced the growth inhibitory effects of Cd and Pb on cucumber seedlings. Cd and Pb absorption in cucumber seedlings was also decreased. Further, γ-PGA decreased the malondialdehyde content, and increased the proline content and the total antioxidant capacity of cucumber seedlings in a dose-dependent manner. Infrared spectral characterization of γ-PGA-Cd and γ-PGA-Pb showed that Cd2+ and Pb2+ bind to free carboxyl groups on γ-PGA. Furthermore, γ-PGA-Cd and γ-PGA-Pb were degraded by 22.02 and 24.68%, respectively, within 28 weeks. The chelating rate of γ-PGA-Pb and γ-PGA-Cd reached 27.26 and 14.28%, respectively. Further, γ-PGA alleviated the negative effects of Cd and Pb on soil microorganisms. Thus, γ-PGA can effectively reduce the accumulation of heavy metals in crops caused by heavy metal pollution of farmland, and has significant application value.
KeywordsPoly-γ-glutamic acid Bio-chelator Pb pollution Cd pollution Cucumis sativus L. Soil microorganisms
This work was funded by The Key Projects in the National Science & Technology Pillar Program during the Twelfth Five-year Plan Period (No. 2015BAD15B04), the National Nature Science Foundation of China (21506098), and the Natural Science Foundation of the Jiangsu (BK20150946).
- Boeddi B, Oravecz AR, Lehoczki E (1995) Effect of cadmium on organization and photoreduction of protochlorphyllide in dark-grown leaves and etioplast inner membrane preparations of wheat. Photosynthetica 31:411–420Google Scholar
- Evangelou MWH (2007) Biochelators as an alternative to EDTA and other synthetic chelators for the phytoextraction of heavy metals (Cu, Cd, Pb) from soil. Rwth AachenGoogle Scholar
- Guo Z, Yang N, Zhu C, Gan L (2017) Exogenously applied poly-γ-glutamic acid alleviates salt stress in wheat seedlings by modulating ion balance and the antioxidant system. Environ Sci Pollut R, 1–7Google Scholar
- Hu B, Wang J, Jin B, Li Y, Shi Z (2017) Assessment of the potential health risks of heavy metals in soils in a coastal industrial region of the Yangtze River Delta. Environ Sci Pollut RGoogle Scholar
- Iverson WP, Brinckman FE (1978) Microbial metabolism of heavy metals. Water pollution. Microbiology 2:201–232Google Scholar
- Knight BP, Mcgrath SP, Chaudri AM (1997) Biomass carbon measurements and substrate utilization patterns of microbial populations from soils amended with cadmium, copper, or zinc. Appl Environ Microbiol 63:39–43Google Scholar
- Koskan LP, Meah ARY, Sanders LJ, Ross RJ (1998) Method and composition for enhanced hydroponic plant productivity with polyamino acids. USGoogle Scholar
- Liao MT, Hedley MJ, Woolley DJ, Brooks RR, Nichols MA (2000) Copper uptake and translocation in chicory (Cichorium intybus L. cv. Grasslands Puna) and tomato (Lycopersicon esculentum Mill. cv. Rondy) plants grown in NFT system. I. Copper uptake and distribution in plants. Plant Soil 221:135–142CrossRefGoogle Scholar
- Meyer CL, Juraniec M, Huguet S, Chaves-Rodriguez E, Salis P, Isaure MP, Goormaghtigh E, Verbruggen N (2015) Intraspecific variability of cadmium tolerance and accumulation, and cadmium-induced cell wall modifications in the metal hyperaccumulator Arabidopsis halleri. J Exp Bot 66:3215–3227CrossRefGoogle Scholar
- Yang ZH, Dong CD, Chen CW, Sheu YT, Kao CM (2017) Using poly-glutamic acid as soil-washing agent to remediate heavy metal-contaminated soils. Environ Sci Pollut R 1–12Google Scholar