Browsing by Author "Arun Vishnu Kumar"

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Effect of Rhizospheric application of NO on soil characteristics and functional attributes of Spinacia oleracea grown in untreated wastewater irrigated soil of Lohta Varanasi
(Springer Science and Business Media Deutschland GmbH, 2025) Pradeep Kumar Yadav; Arun Vishnu Kumar; Anita K. Singh
Aims: Heavy metal contamination in soils poses a serious threat to crop health and productivity, necessitating eco-friendly mitigation approaches. This study investigates the potential of nitric oxide (NO), applied as sodium nitroprusside (SNP), as an exogenous agent to alleviate metal-induced toxicity in Spinacia oleracea. It evaluates NO’s role in regulating metal accumulation, oxidative stress, and overall plant performance. Method: NO was applied at five concentrations (10, 50, 100, 200, and 500 µM) in the rhizospheric zone of metal-contaminated soil for growing spinach plants. Untreated contaminated soil served as the control. Physiological attributes such as oxidative biomarkers [hydrogen peroxide (H₂O₂), superoxide radicals (SOR), and malondialdehyde (MDA) content], antioxidant enzyme activities [superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)], and leaf surface morphology using scanning electron microscopy (SEM) were assessed. High-resolution mass spectrometry (HRMS) was used to quantify metabolite profiles to find out their role in regulating metal toxicity. Results: Among all treatments, 100 µM NO was found to be most effective, significantly enhanced biomass and reduced levels of H₂O₂, SOR, and MDA. A concurrent reduction in SOD, POD, and CAT activities indicated alleviated oxidative stress. SEM analysis showed improved leaf surface integrity, and HRMS confirmed better metabolic balance and reduced metal ion concentrations in the plant parts. Conclusion: Application of NO at 100 µM will be able to mitigate heavy metal toxicity, for enhancing physiological performance and growth of S. oleracea. This approach offers a promising and sustainable strategy for improving crop productivity in metal-contaminated soils. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.
Hydrogen sulfide (H2S) as a protagonist to regulate metal stress in plants: an overview of physiological steps
(Springer, 2025) Pradeep Kumar Yadav; Arun Vishnu Kumar; Anita K. Singh
Hydrogen sulfide (H2S) is one of the gaseous molecules that act as a signaling agent at lower concentrations. It performs significant action in protecting the plants against adverse conditions by being part of the signaling network. In the current review, heavy metal stress has been considered as one of the major stress factors, as it affects the vital function of plants. The heavy metals also activate the expression of transcription factors and protein signaling pathways to regulate the expression of several stress-responsive genes. Further, H2S signaling triggers gene expression in the antioxidant defense system. Along with the endogenous level, the exogenous treatment with H2S up to a certain concentration maintains the redox balance and dynamic regulation of antioxidant enzyme systems to regulate the metal toxicity. It promotes more expression of chelators synthetic genes like PCS1, PCS2, MT1A, MT1B, and MT2B to produce more phytochelatins (PCs) and Metallothioneins (MTs), to scavenge the metals. H2S manages metal toxicity through various signaling processes by modulating extracellular signals into intracellular responses. The present review is based on the understanding of metal toxicity regulation with the intrusion of H2S signaling molecules. Overall, it will try to provide mechanistic action of H2S signaling on physiological performance and ultra-structure changes in the plant in order to regulate the metal stress. © The Author(s), under exclusive licence to Society for Plant Biochemistry and Biotechnology 2025.
Physiological and Metabolic Characterization of Spinacia oleracea Grown in Metal-Polluted Soil: A Focus on Rhizospheric Application of H2S
(Springer, 2025) Pradeep Kumar Yadav; Arun Vishnu Kumar; Anita K. Singh
The study examines the effect of rhizospheric application of hydrogen sulfide (H2S) on Spinacia oleracea (spinach) plants grown in pots containing metal-contaminated soil. Various concentrations of H2S, in the form of Sodium hydrosulfide (NaHS), (10, 50, 100, 200, and 500 µM), were applied to the rhizospheric zone to assess their effect on soil and plant physiology. Plants grown in control soil exhibited reduced fresh biomass along with increased production of oxidative biomarkers like hydrogen peroxide (H2O2), superoxide radical (SOR), and malondialdehyde (MDA), and antioxidative enzymes superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). The rhizospheric application of H2S resulted in a significant increase in fresh biomass, with the 200 µM dose showing the highest increase of 37% compared to plants in control soil. Additionally, H2O2, SOR, and MDA production were maximally reduced by 38%, 52%, and 48%, respectively, in the 200 µM treatment group compared to the control. The activities of antioxidative enzymes, such as SOD, POD, and CAT, increased maximally at 200 µM dose. High-resolution mass spectrometry (HRMS) data and scanning electron microscopy (SEM) supported the superior performance of plants at this dose. Thus, among all the doses, the 200 µM dose of H2S significantly mitigated metal toxicity, promoting plant growth and functional traits. The correlation analysis further confirmed these results, revealing a dose-dependent decrease in metal residues in plants treated with H₂S. This approach holds significant potential for enhancing both the quality and yield of plants cultivated in metal-contaminated soils. Further, future research should be conducted for optimal application methods to increase the efficiency and promote widespread adoption of this strategy. © Prof. H.S. Srivastava Foundation for Science and Society 2025.