Citric acid assisted phytoremediation of cadmium by Brassica napus L.
Phytoextraction is an eco-friendly and cost-effective technique for removal of toxins, especially heavy metals and metalloids from contaminated soils by the roots of high biomass producing plant species with subsequent transport to aerial parts. Lower metal bioavailability often limits the phytoextraction. Organic chelators can help to improve this biological technique by increasing metal solubility. The aim of the present study was to investigate the possibility of improving the phytoextraction of Cd by the application of citric acid. For this purpose, plants were grown in hydroponics under controlled conditions. Results indicated that Cd supply significantly decreased the plant growth, biomass, pigments, photosynthetic characteristics and protein contents which were accompanied by a significant increase in Cd concentration, hydrogen peroxide (H₂O₂), electrolyte leakage, malondialdehyde (MDA) accumulation and decrease in antioxidant capacity. The effects were dose dependent with obvious effects at higher Cd concentration. Application of CA significantly enhanced Cd uptake and its accumulation in plant roots, stems and leaves. Citric acid alleviated Cd toxicity by increasing plant biomass and photosynthetic and growth parameters alone and in combination with Cd and by reducing oxidative stress as observed by reduction in MDA and H₂O₂ production and decreased electrolyte leakage induced by Cd stress. Application of CA also enhanced the antioxidant enzymes activity alone and under Cd stress. Thus, the data indicate that exogenous CA application can increase Cd uptake and minimize Cd stress in plants and may be beneficial in accelerating the phytoextraction of Cd through hyper-accumulating plants such as Brassica napus L.
Department of Environmental Sciences, Government College University, Allama Iqbal Road, Faisalabad 38000, Pakistan.
Sana
S
Ehsan
Department of Environmental Sciences, Government College University, Allama Iqbal Road, Faisalabad 38000, Pakistan. Electronic address: shafaqataligill@yahoo.com.
Shafaqat
S
Ali
Department of Environmental Sciences, Government College University, Allama Iqbal Road, Faisalabad 38000, Pakistan.
Shamaila
S
Noureen
Nuclear Institute for Agriculture and Biology (NIAB), P.O. Box 128, Jhang Road, Faisalabad, Pakistan.
Khalid
K
Mahmood
Department of Environmental Sciences, Government College University, Allama Iqbal Road, Faisalabad 38000, Pakistan.
Mujahid
M
Farid
Nuclear Institute for Agriculture and Biology (NIAB), P.O. Box 128, Jhang Road, Faisalabad, Pakistan.
Wajid
W
Ishaque
Department of Environmental Sciences, Government College University, Allama Iqbal Road, Faisalabad 38000, Pakistan.
Muhammad Bilal
MB
Shakoor
Department of Environmental Sciences, Government College University, Allama Iqbal Road, Faisalabad 38000, Pakistan.
Muhammad
M
Rizwan
D001673:Biodegradation, Environmental / Q000187:drug effects; D029688:Brassica napus / Q000187:drug effects* / Q000378:metabolism*; D002104:Cadmium / Q000032:analysis / Q000378:metabolism* / Q000633:toxicity*; D002614:Chelating Agents / Q000378:metabolism / Q000494:pharmacology; D019343:Citric Acid / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology; D008315:Malondialdehyde / Q000378:metabolism / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects; D018517:Plant Roots / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism / Q000633:toxicity
D002614:Chelating Agents; D012989:Soil Pollutants; D002104:Cadmium; D019343:Citric Acid; D008315:Malondialdehyde; D006861:Hydrogen Peroxide
Antioxidant enzymes; Biomass; Cadmium; Citric acid; Growth; Phytoremediation