Exogenous plant growth regulators improved phytoextraction efficiency by Amaranths hypochondriacus L. in cadmium contaminated soil
- 200 Downloads
Phytoextraction assisted by plant growth regulators (PGRs) is gaining popularity in phytoremediation applications. A pot experiment was conducted to compare the effects of foliar applications of 11 PGRs, including Indole-3-acetic acid (IAA), Indole-3-butyric acid (IBA), diethyl aminoethyl hexanoate (DA-6), 6-Benzylaminopurine (6-BA), 1-naphthylacetic acid (NAA), Abscisic acid (ABA), 2,4-Dichlorophenoxyacetic acid (2,4-D), Ethrel (ETH), Brassinolide (BR), Gibberellin (GA3), and Compound sodium nitrophenolate (CSN) on plant development, chlorophyll content, antioxidant enzyme activities, Cd phytoextraction capacity and micro-distribution of Amaranthus hypochondriacus L. grown in Cd contaminated soil. The effect on biomass yield was dependent on the PGRs type, with IBA being the most efficient. The addition of PGRs increased Cd extraction efficiency, with their effect decreasing in the order: IAA > DA-6 > IBA > 2,4-D > 6-BA > NAA > BR > CSN > ETH > GA3 > ABA. Application of PGRs increased Cd concentrations in leaves and stems but reduction was found in roots (except for 2,4-D). Exogenous PGRs increased the activities of stress ameliorating enzymes (SOD and CAT) and led to a reduction in MDA (malondialdehyde) concentration. In leaves, scanning electron microscope-Energy dispersive spectrometer (SEM–EDS) confirmed that application of IBA or DA-6 further fixed more Cd in upper and lower epidermal cells, which might relate to more Cd migration from roots to shoots in Amaranthus hypochondriacus L. These findings suggest that the treatment with IBA or DA-6 appears to be optimal for enhancing the phytoextraction efficiency of Amaranthus hypochondriacus L. in Cd contaminated soil.
KeywordsPlant growth regulators Amaranthus hypochondriacus L. Cadmium Antioxidant enzymes Micro-area distribution Phytoextraction efficiency
This research was financially supported by the National Key Technologies R&D Program of China (2015BAD05B05), the National Natural Science Foundation of China (31670513), the Science and Technology Program of Guangdong, China (2018B030324003 and 2016A020221023), National Key R&D Program of China (2016YFD0800704), Special Program for Key Basic Research and Cultivation Project of Guangdong, China (2015A030308015), Program of Bureau of Science and Information Technology of Guangzhou Municipality (201903010022).
PZ and ZL designed the study; SS, XZ and XC carried out the experiments; YF and YL contributed reagents/materials/analysis tools; SS analyzed the data and wrote the manuscript; and MM and CL contributed to language modification.
Compliance with ethical standards
Conflict of interest
The authors declare no conflict of interest.
- Allison LE (1976) Organic carbon. In: Black CA (ed) Methods of soil analysis: part 2. chemical and microbiological properties. American Society of Agronomy, Madison, pp 1367–1378Google Scholar
- Bali S, Kaur P, Kohli SK, Ohri P, Thukral AK, Bhardwaj R, Wijaya L, Alyemeni MN, Ahmad P (2018) Jasmonic acid induced changes in physio-biochemical attributes and ascorbate-glutathione pathway in Lycopersicon esculentum under lead stress at different growth stages. Sci Total Environ 645:1344–1360PubMedCrossRefPubMedCentralGoogle Scholar
- Chen L, Wang D, Long C, Cui ZX (2019) Effect of plant growth regulations on phytoremediation of uranium and cadmium contaminated soil by Zebrina pendula schnizl. Fresenius Environ Bull 28(2A):1434–1442Google Scholar
- Fuentes HD, Khoo CS, Pe T, Muir S, Khan AG (2000) Phytoremediation of a contaminated mine site using plant growth regulators to increase heavy metal uptake. In: Proceedings of the 5th international conference on clean technologies for the mining industry, pp 427–435Google Scholar
- George EF, Hall MA, Klerk GJD (2008) Plant growth regulators I: introduction; auxins, their analogues and inhibitors. Plant propagation by tissue culture. Springer, Dordrecht, pp 175–204Google Scholar
- Long C, Wang D, Chen L, Jiang WJ, Xiang MW (2017) Effect of four kinds of phytohormones on U and Cd accumulation in Helianthus annuus. Chin J Environ Eng 11(5):3251–3256 (in Chinese) Google Scholar
- MAPRC (Ministry of Agriculture of the People’s Republic of China) (2017) Determination of chlorophyll content in fruits, vegetables and derived products—Spectrophotometry method (NY/T 3082-2017). MAPRC, Beijing (in Chinese) Google Scholar
- Verma A, Malik CP, Gupta VK (2011) In Vitro effects of brassinosteroids on the growth and antioxidant enzyme activities in groundnut. ISRN Agron 2012:8Google Scholar
- Wojick M, D’Haen VJ, Tukiendorf A (2005) Cadmium tolerance in Thlaspi caerulescens II: localization of cadmium in Thlaspi caerulescens. Environ Exp Bot 53(2):163–171Google Scholar
- Yu CL (2011) Study on the plant growth regulator enhancing remediation efficiency of Solanum nigrum L. on contaminated soil by cadmium. Harbin University of Science and Technology (in Chinese)Google Scholar