title: Nitric oxide alleviates silver nanoparticles (AgNps)-induced phytotoxicity in Pisum sativum seedlings.
abstract: Understanding the adverse impact of nanoparticles in crop plants has emerged as one of the most interesting fields of plant research. Therefore, this study has been conducted to investigate the impact of silver nanoparticles (AgNps) on Pisium sativum seedlings. Besides this, we have also tested whether nitric oxide (NO) is capable of reducing toxicity of AgNps or not. NO has been found as one of the most fascinating molecules, capable of enhancing plant tolerance to different environmental stresses. The results of the present study showed that AgNps treatments (1000 μM and 3000 μM) significantly declined growth parameters, photosynthetic pigments and chlorophyll fluorescence of pea seedlings, which could be correlated with increased accumulation of Ag in root and shoot of pea seedlings. In contrast, addition of SNP (100 μM; a donor of NO) successfully ameliorated AgNp-induced adverse effects on these parameters as it reduced accumulation of Ag and repaired damaged tissues. Levels of oxidative stress markers (SOR, H2O2and MDA) were enhanced while their levels significantly reduced under SNP addition. AgNps (1000 μM and 3000 μM) significantly stimulated the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX) while inhibited activities of glutathione reductase (GR) and dehydroascorbate reductase (DHAR). AgNps also considerably declined the total ascorbate and glutathione contents and severely damaged leaf and root anatomical structures. On the other hand, addition of SNP further increased the level of SOD, APX, GR and DHAR and significantly increased the decreased levels of total ascorbate and glutathione contents, and repaired anatomical structures. In conclusion, this study suggests that AgNps treatments adversely decreased growth, pigments and photosynthesis due to enhanced level of Ag and oxidative stress. However, SNP addition successfully ameliorates adverse impact of AgNps on pea seedlings by regulating the Ag uptake, antioxidant system, oxidative stress and anatomical structures of root and shoot.
authors.affiliation: Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, India. Electronic address: dktripathiau@gmail.com.
authors.forename: Durgesh Kumar
authors.initials: DK
authors.lastname: Tripathi
authors.affiliation: D D Pant Interdisciplinary Research Laboratory, Department of Botany, University of Allahabad, Allahabad 211002, India.
authors.forename: Swati
authors.initials: S
authors.lastname: Singh
authors.affiliation: D D Pant Interdisciplinary Research Laboratory, Department of Botany, University of Allahabad, Allahabad 211002, India.
authors.forename: Shweta
authors.initials: S
authors.lastname: Singh
authors.affiliation: Govt. Pt. R.S.T. Degree College, Bhiayathan, Surajpur, Chhattisgarh, India.
authors.forename: Prabhat Kumar
authors.initials: PK
authors.lastname: Srivastava
authors.affiliation: Govt. Ramanuj Pratap Singhdev Post Graduate College, Baikunthpur, Koriya 497335, 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.
authors.forename: Samiksha
authors.initials: S
authors.lastname: Singh
authors.affiliation: Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Allahabad 211002, India.
authors.forename: Sheo Mohan
authors.initials: SM
authors.lastname: Prasad
authors.affiliation: Nanotechnology Application Centre, University of Allahabad, Allahabad 211002, India. Electronic address: prashant2singh@gmail.com.
authors.forename: Prashant Kumar
authors.initials: PK
authors.lastname: Singh
authors.affiliation: Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, India.
authors.forename: Nawal Kishore
authors.initials: NK
authors.lastname: Dubey
authors.affiliation: Nanotechnology Application Centre, University of Allahabad, Allahabad 211002, India.
authors.forename: Avinash Chand
authors.initials: AC
authors.lastname: Pandey
authors.affiliation: D D Pant Interdisciplinary Research Laboratory, Department of Botany, University of Allahabad, Allahabad 211002, India. Electronic address: dkchauhanau@gmail.com.
authors.forename: Devendra Kumar
authors.initials: DK
authors.lastname: Chauhan
mesh_terms: D060387:Ascorbate Peroxidases / Q000378:metabolism; D001205:Ascorbic Acid / Q000378:metabolism; D002734:Chlorophyll / Q000737:chemistry / Q000378:metabolism; D005453:Fluorescence; D005978:Glutathione / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000378:metabolism / Q000494:pharmacology; D009599:Nitroprusside / Q000378:metabolism / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects; D018532:Pisum sativum / Q000187:drug effects* / Q000378:metabolism; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects* / Q000378:metabolism; D012834:Silver / Q000737:chemistry / Q000633:toxicity*; D013482:Superoxide Dismutase / Q000378:metabolism; D014961:X-Ray Diffraction
chemical_list: D020030:Nitric Oxide Donors; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D002734:Chlorophyll; D009599:Nitroprusside; D009569:Nitric Oxide; D012834:Silver; D008315:Malondialdehyde; D006861:Hydrogen Peroxide; D060387:Ascorbate Peroxidases; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005978:Glutathione; D001205:Ascorbic Acid
keywords: Anatomical structures; Nitric oxide; Oxidative stress; Pea seedlings; Silver nanoparticles