title: Characterization of seed germination, seedling growth, and associated metabolic responses of Brassica juncea L. cultivars to elevated nickel concentrations.
abstract: Seed germination and seedling growth responses of three Brassica juncea L. cultivars, namely Varuna, Kranti, and Pusa Jai Kisan, to nickel have been characterized. Ni suppressed the seed germination differentially, suppression being greater in cv. Kranti than in others. On the basis of seedling growth performance, cv. Varuna proved most tolerant to Ni. The Ni accumulation in seedlings differed strongly among the three cultivars. The lowest and highest Ni contents were observed in the seedlings of cvs. Kranti and Pusa Jai Kisan, respectively. Despite substantial Ni accumulation, cv. Varuna was most tolerant to Ni. Ni accumulation in seedlings was accompanied by differentially altered Fe and K contents and increased levels of non-protein thiols and free proline. The O2- and H2O2 contents and their respective scavenging enzymes in the seedlings responded differentially to the Ni treatment suggesting the involvement of redox imbalance in the development of Ni toxicity. Interestingly, the greater Ni tolerance of cv. Varuna coincided with the elevated constitutive activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX). The data have implications for seedling establishment under Ni-rich conditions and in turn for phytoremediation.
authors.affiliation: Department of Biosciences, Himachal Pradesh University, Shimla, 171005, India.
authors.forename: Sveta
authors.initials: S
authors.lastname: Thakur
authors.affiliation: Department of Biosciences, Himachal Pradesh University, Shimla, 171005, India. shantissharma@hotmail.com.
authors.forename: Shanti S
authors.initials: SS
authors.lastname: Sharma
mesh_terms: D060387:Ascorbate Peroxidases / Q000378:metabolism; D001673:Biodegradation, Environmental; D002374:Catalase / Q000378:metabolism; D018525:Germination; D015227:Lipid Peroxidation; D009149:Mustard Plant / Q000187:drug effects / Q000502:physiology*; D009532:Nickel / Q000494:pharmacology*; D018384:Oxidative Stress; D010940:Plant Proteins / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000502:physiology*; D012639:Seeds / Q000187:drug effects / Q000502:physiology*; D012989:Soil Pollutants / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D017382:Reactive Oxygen Species; D012989:Soil Pollutants; D009532:Nickel; D060387:Ascorbate Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase
keywords: Indian mustard; Nickel; Phytoremediation; Redox imbalance; Seed germination; Seedling growth