Nitric oxide alleviates silver nanoparticles (AgNps)-induced phytotoxicity in Pisum sativum seedlings

• Published in: Plant physiology and biochemistry Vol. 110; pp. 167 - 177
• Main Authors: Tripathi, Durgesh Kumar, Singh, Swati, Singh, Shweta, Srivastava, Prabhat Kumar, Singh, Vijay Pratap, Singh, Samiksha, Prasad, Sheo Mohan, Singh, Prashant Kumar, Dubey, Nawal Kishore, Pandey, Avinash Chand, Chauhan, Devendra Kumar
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01.01.2017
• Subjects: Anatomical structures; Ascorbate Peroxidases - metabolism; Ascorbic Acid - metabolism; Chlorophyll - chemistry; Chlorophyll - metabolism; Fluorescence; Glutathione - metabolism; Glutathione Reductase - metabolism; Hydrogen Peroxide - metabolism; Malondialdehyde - metabolism; Metal Nanoparticles - chemistry; Metal Nanoparticles - toxicity; Metal Nanoparticles - ultrastructure; Microscopy, Electron, Transmission; Nitric oxide; Nitric Oxide - metabolism; Nitric Oxide Donors - metabolism; Nitric Oxide Donors - pharmacology; Nitroprusside - metabolism; Nitroprusside - pharmacology; Oxidative stress; Oxidative Stress - drug effects; Pea seedlings; Photosynthesis - drug effects; Pisum sativum - drug effects; Pisum sativum - metabolism; Plant Leaves - drug effects; Plant Leaves - metabolism; Plant Proteins - metabolism; Plant Roots - drug effects; Plant Roots - metabolism; Plant Shoots - drug effects; Plant Shoots - metabolism; Reactive Oxygen Species - metabolism; Seedlings - drug effects; Seedlings - metabolism; Silver - chemistry; Silver - toxicity; Silver nanoparticles; Superoxide Dismutase - metabolism; X-Ray Diffraction; Oxidative stress; APX; MDA; H2O2; NPQ; UE; PHL; Pl; SP; Silver nanoparticles; EEC; Pea seedlings; SOD; F0; DHAR; XYL; GR; EP; VB; Nitric oxide; Fv/Fm; RH; ROS; SOR; Fv/F0; LE; Anatomical structures; VT; qP
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2016.06.015

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, H2O2 and 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. •AgNps adversely affects growth and photosynthesis in Pisum sativum.•It happens because of enhanced accumulation of AgNps and ROS.•NO (SNP) protects pea seedlings against AgNps by regulating accumulation of Ag and ROS, and antioxidants.