title: Sulphur alters chromium (VI) toxicity in Solanum melongena seedlings: Role of sulphur assimilation and sulphur-containing antioxidants.
abstract: The present study investigates modulation in hexavalent chromium [Cr(VI) 25 μM] toxicity by sulphur (S; 0.5, 1.0 and 1.5 mM S as low (LS), medium (MS) and high sulphur (HS), respectively) in Solanum melongena (eggplant) seedlings. Biomass accumulation (fresh and dry weights), photosynthetic pigments, photosynthetic oxygen evolution and S content were declined by Cr(VI) toxicity. Furthermore, fluorescence characteristics (JIP-test) were also affected by Cr(VI), but Cr(VI) toxicity on photosystem II photochemistry was ameliorated by HS treatment via reducing damaging effect on PS II reaction centre and its reduction side. Enhanced respiration, Cr content and oxidative biomarkers: superoxide radical, hydrogen peroxide, lipid peroxidation and membrane damage were observed under Cr(VI) stress. Though Cr(VI) enhanced adenosine triphasphate sulfurylase (ATPS) and o-acetylserine(thiol)lyase (OASTL), glutathione-S-transferase (GST), glutathione reductase (GR) and ascorbate peroxidase (APX) activity, and content of total glutathione, cysteine and NP-SH, however, their levels/activity were further enhanced by S being maximum with HS treatment. The results show that Cr(VI) toxicity does increase under LS treatment while HS protected Cr(VI)-induced damaging effects in brinjal seedlings. Under HS treatment, in mitigating Cr(VI) toxicity, S assimilation and its associated metabolites such as cysteine, glutathione and NP-SH play crucial role.
authors.affiliation: Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Allahabad 211002, India.
authors.forename: Madhulika
authors.initials: M
authors.lastname: Singh
authors.affiliation: Govt. Ramanuj Pratap Singhdev Post Graduate College, Baikunthpur, 497335 Koriya, Chhattisgarh, India; Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India.
authors.forename: Bishwajit Kumar
authors.initials: BK
authors.lastname: Kushwaha
authors.affiliation: Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Allahabad 211002, India.
authors.forename: Samiksha
authors.initials: S
authors.lastname: Singh
authors.affiliation: Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, India.
authors.forename: Vipin
authors.initials: V
authors.lastname: Kumar
authors.affiliation: Govt. Ramanuj Pratap Singhdev Post Graduate College, Baikunthpur, 497335 Koriya, Chhattisgarh, India. Electronic address: vijaypratap.au@gmail.com.
authors.forename: Vijay Pratap
authors.initials: VP
authors.lastname: Singh
authors.affiliation: Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Allahabad 211002, India. Electronic address: profsmprasad@gmail.com.
authors.forename: Sheo Mohan
authors.initials: SM
authors.lastname: Prasad
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D018533:Biomass; D019069:Cell Respiration / Q000187:drug effects; D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D002857:Chromium / Q000633:toxicity*; D005453:Fluorescence; D006861:Hydrogen Peroxide / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology; D018517:Plant Roots / Q000033:anatomy & histology / Q000187:drug effects; D018520:Plant Shoots / Q000033:anatomy & histology / Q000187:drug effects; D036226:Seedlings / Q000187:drug effects / Q000502:physiology*; D032323:Solanum melongena / Q000187:drug effects / Q000502:physiology*; D013312:Stress, Physiological / Q000187:drug effects; D013455:Sulfur / Q000378:metabolism* / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D002857:Chromium; D002734:Chlorophyll; C074702:chromium hexavalent ion; D008315:Malondialdehyde; D013455:Sulfur; D006861:Hydrogen Peroxide; D000077194:Chlorophyll A
keywords: Antioxidants; Chromium; Oxidative stress; Solanum lycopersicum; Sulphur metabolism