title: Copper-resistant bacteria reduces oxidative stress and uptake of copper in lentil plants: potential for bacterial bioremediation.
abstract: For effective microbe-assisted bioremediation, metal-resistant plant growth-promoting bacteria (PGPB) must facilitate plant growth by restricting excess metal uptake in plants, leading to prevent its bio-amplification in the ecosystem. The aims of our study were to isolate and characterize copper (Cu)-resistant PGPB from waste water receiving contaminated soil. In addition, we investigated the phytotoxic effect of copper on the lentil plants inoculated with copper-resistant bacteria Providencia vermicola, grown in copper-contaminated soil. Copper-resistant P. vermicola showed multiple plant growth promoting characteristics, when used as a seed inoculant. It protected the lentil plants from copper toxicity with a considerable increase in root and shoot length, plant dry weight and leaf area. A notable increase in different gas exchange characteristics such as A, E, C i , g s , and A/E, as well as increase in N and P accumulation were also recorded in inoculated plants as compared to un-inoculated copper stressed plants. In addition, leaf chlorophyll content, root nodulation, number of pods, 1,000 seed weight were also higher in inoculated plants as compared with non-inoculated ones. Anti-oxidative defense mechanism improved significantly via elevated expression of reactive oxygen species -scavenging enzymes including ascorbate peroxidase, superoxide dismutase, catalase, and guaiacol peroxidase with alternate decrease in malondialdehyde and H2O2 contents, reduced electrolyte leakage, proline, and total phenolic contents suggesting that inoculation of P. vermicola triggered heavy metals stress-related defense pathways under copper stress. Overall, the results demonstrated that the P. vermicola seed inoculation confer heavy metal stress tolerance in lentil plant which can be used as a potent biotechnological tool to cope with the problems of copper pollution in crop plants for better yield.
authors.affiliation: Department of Environmental Sciences and Engineering, Government College University, Faisalabad, 38000, Pakistan.|Institute of Crop Science and Zhejiang Key Laboratory of Crop Germplasm, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Faisal
authors.initials: F
authors.lastname: Islam
authors.affiliation: Department of Environmental Sciences and Engineering, Government College University, Faisalabad, 38000, Pakistan. rida_akash@hotmail.com.
authors.forename: Tahira
authors.initials: T
authors.lastname: Yasmeen
authors.affiliation: Department of Botany, Government College University, Faisalabad, 38000, Pakistan.
authors.forename: Qasim
authors.initials: Q
authors.lastname: Ali
authors.affiliation: Centre of Agricultural Biochemistry and Biotechnology, University of Agriculture, Faisalabad, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Mubin
authors.affiliation: Department of Environmental Sciences and Engineering, Government College University, Faisalabad, 38000, Pakistan.
authors.forename: Shafaqat
authors.initials: S
authors.lastname: Ali
authors.affiliation: Department of Environmental Sciences and Engineering, Government College University, Faisalabad, 38000, Pakistan.
authors.forename: Muhammad Saleem
authors.initials: MS
authors.lastname: Arif
authors.affiliation: Department of Environmental Sciences and Engineering, Government College University, Faisalabad, 38000, Pakistan.
authors.forename: Sabir
authors.initials: S
authors.lastname: Hussain
authors.affiliation: Department of Environmental Sciences and Engineering, Government College University, Faisalabad, 38000, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Riaz
authors.affiliation: Department of Environmental Sciences and Engineering, Government College University, Faisalabad, 38000, Pakistan.
authors.forename: Farhat
authors.initials: F
authors.lastname: Abbas
mesh_terms: D060387:Ascorbate Peroxidases / Q000378:metabolism; D001419:Bacteria / Q000187:drug effects* / Q000378:metabolism; D001673:Biodegradation, Environmental; D002374:Catalase / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D003300:Copper / Q000378:metabolism* / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D006861:Hydrogen Peroxide / Q000378:metabolism; D027806:Lens Plant / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology; D019216:Metals, Heavy / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D018515:Plant Leaves / Q000378:metabolism; D011532:Providencia / Q000187:drug effects* / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D062065:Wastewater / Q000382:microbiology*
chemical_list: D060387:Ascorbate Peroxidases; D002374:Catalase; D002734:Chlorophyll; D003300:Copper; D006861:Hydrogen Peroxide; D019216:Metals, Heavy; D013482:Superoxide Dismutase; D062065:Wastewater
keywords: Antioxidation; Cu-resistant bacteria; Lentil; Metal uptake; Plant growth