title: Silicon nanoparticles more effectively alleviated UV-B stress than silicon in wheat (Triticum aestivum) seedlings.
abstract: The role of silicon (Si) in alleviating biotic as well as abiotic stresses is well known. However, the potential of silicon nanoparticle (SiNP) in regulating abiotic stress and associated mechanisms have not yet been explored. Therefore, in the present study hydroponic experiments were conducted to investigate whether Si or SiNp are more effective in the regulation of UV-B stress. UV-B (ambient and enhanced) radiation caused adverse effect on growth of wheat (Triticum aestivum) seedlings, which was accompanied by declined photosynthetic performance and altered vital leaf structures. Levels of superoxide radical and H2O2were enhanced by UV-B as also evident from their histochemical stainings, which was accompanied by increased lipid peroxidation (LPO) and electrolyte leakage. Activities of superoxide dismutase and ascorbate peroxidase were inhibited by UV-B while catalase and guaiacol peroxidase, and all non-enzymatic antioxidants were stimulated by UV-B. Although, nitric oxide (NO) content was increased at all tested combinations, but its maximum content was observed under SiNps together with UV-B enhanced treatment. Pre-additions of SiNp as well as Si protected wheat seedlings against UV-B by regulating oxidative stress through enhanced antioxidants. Data indicate that SiNp might have protected wheat seedlings through NO-mediated triggering of antioxidant defense system, which subsequently counterbalance reactive oxygen species-induced damage to photosynthesis. Further, SiNp appear to be more effective in reducing UV-B stress than Si, which is related to its greater availability to wheat seedlings.
authors.affiliation: Centre of Advanced Study in Botany, Department of Botany, Banaras Hindu University Varanasi, 221005, 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: 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. Electronic address: profsmprasad@gmail.com.
authors.forename: Sheo Mohan
authors.initials: SM
authors.lastname: Prasad
authors.affiliation: Centre of Advanced Study in Botany, Department of Botany, Banaras Hindu University Varanasi, 221005, India.
authors.forename: Nawal Kishore
authors.initials: NK
authors.lastname: Dubey
authors.affiliation: D. D. Pant Interdisciplinary Research Laboratory, Department of Botany, University of Allahabad, Allahabad, 211002, India. Electronic address: dkchauhanau@yahoo.com.
authors.forename: Devendra Kumar
authors.initials: DK
authors.lastname: Chauhan
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D060387:Ascorbate Peroxidases / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D018527:Hydroponics / Q000379:methods; D015227:Lipid Peroxidation / Q000187:drug effects / Q000528:radiation effects; D053768:Metal Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D018384:Oxidative Stress / Q000187:drug effects / Q000528:radiation effects; D010316:Particle Size; D010788:Photosynthesis / Q000187:drug effects / Q000528:radiation effects; D063245:Plant Development / Q000187:drug effects / Q000528:radiation effects; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D010940:Plant Proteins / Q000378:metabolism; D011837:Radiation-Protective Agents / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology; D036226:Seedlings / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects; D012825:Silicon / Q000737:chemistry / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D014908:Triticum / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects; D014466:Ultraviolet Rays; D014961:X-Ray Diffraction
chemical_list: D000975:Antioxidants; D010940:Plant Proteins; D011837:Radiation-Protective Agents; D013481:Superoxides; D006861:Hydrogen Peroxide; D060387:Ascorbate Peroxidases; D013482:Superoxide Dismutase; D012825:Silicon
keywords: Antioxidants; Nitric oxide; Oxidative stress; Silicon; Silicon nanoparticle; UV-B radiation