12 results
Search Results
Now showing 1 - 10 of 12
PublicationRetracted The interplay between reactive oxygen and nitrogen species contributes in the regulatory mechanism of the nitro-oxidative stress induced by cadmium in Arabidopsis(Elsevier B.V., 2018) Shiliang Liu; Rongjie Yang; Durgesh Kumar Tripathi; Xi Li; Wei He; Mengxi Wu; Shafaqat Ali; Mingdong Ma; Qingsu Cheng; Yuanzhi PanNitric oxide ([rad]NO) involved in various metabolic processes in plants. Although its significant influence has been established, the exact mechanisms of [rad]NO-derived products under metal-stress conditions are largely unknown. Here, we investigated the key components of reactive oxygen/nitrogen species (ROS/RNS) metabolisms under cadmium (Cd) stress using Arabidopsis as the model plant. Exposure to Cd disturbed redox homeostasis and increased lipid peroxidation, thus triggering oxidative stress. Complementarily, Cd caused differential changes in the selected amino acids: a promotion in partial amino acids might be a genotype-specific trait, while the phenylalanine ammonia-lyase activity increased in a dose-dependent manner in shoots. Furthermore, [rad]NO production as well as S-nitrosoglutathione (GSNO) reductase (GSNOR) activity were up-regulated by Cd with the simultaneous depletion of GSNO. Correspondingly, S-nitrosothiols were involved in generating peroxynitrite and tyrosine nitration of protein (NO2-Tyr), in accordance with the regulation of [rad]NO-mediated post-translational modifications in antioxidant systems, including the ascorbate-glutathione cycle, amino acids and phenolic compounds, thereby provoking nitrosative stress. Our data provide comprehensive evidences regarding the clear relationships between the metabolisms of ROS and RNS, supporting the indicator role of NO2-Tyr as a nitrosative stress in plants, and help to provide a better understanding of the ROS/RNS interaction under stress conditions. © 2017 Elsevier B.V.PublicationArticle Interactive Effect of Silicon (Si) and Salicylic Acid (SA) in Maize Seedlings and Their Mechanisms of Cadmium (Cd) Toxicity Alleviation(Springer New York LLC, 2019) Swati Singh; Vijay Pratap Singh; Sheo Mohan Prasad; Shivesh Sharma; Naleeni Ramawat; Nawal Kishore Dubey; Durgesh Kumar Tripathi; Devendra Kumar ChauhanThe present study has been conducted to evaluate the impact of silicon (Si) and salicylic acid (SA) in the regulation of Cd-induced toxicity in maize seedlings. Cadmium (Cd: 100 µM) significantly reduced root and shoot fresh weight and length, photosynthetic pigments, total soluble protein content and chlorophyll fluorescence parameters. Cadmium decreased root and shoot length by 23 and 19% and fresh weight by 27 and 24%, respectively when compared to their respective controls. Similarly, total chlorophyll, carotenoids and total soluble protein were decreased by 21, 18 and 28%, respectively by Cd. In contrast, the addition of SA (500 µM) and Si (10 µM), and their combination (SA + Si) together with Cd treatment successfully ameliorated Cd-induced harmful impacts on studied parameters as SA and Si alone and in combination reduced Cd accumulation and oxidative stresses and thus refurbish the damages. Cd significantly stimulated activity of superoxide dismutase while inhibited activities of ascorbate peroxidase (APX), glutathione reductase (GR) and dehydroascorbate reductase (DHAR), and declined total ascorbate and glutathione contents. In contrast, the addition of SA and Si alone and in combination stimulated the activities of APX, GR and DHAR and significantly increased levels of total ascorbate and glutathione. In conclusion, the present study suggested that although SA and Si both alone are able to alleviate Cd-induced toxicity in maize seedlings, but their combination was the most effective in nullifying Cd-induced toxicity in maize seedlings. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.PublicationArticle Silicon nanoparticles more effectively alleviated UV-B stress than silicon in wheat (Triticum aestivum) seedlings(Elsevier Masson SAS, 2017) Durgesh Kumar Tripathi; Swati Singh; Vijay Pratap Singh; Sheo Mohan Prasad; Nawal Kishore Dubey; Devendra Kumar ChauhanThe 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 H2O2 were 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. © 2016 Elsevier Masson SASPublicationArticle Nitric oxide alleviates silver nanoparticles (AgNps)-induced phytotoxicity in Pisum sativum seedlings(Elsevier Masson SAS, 2017) Durgesh Kumar Tripathi; Swati Singh; Shweta Singh; Prabhat Kumar Srivastava; Vijay Pratap Singh; Samiksha Singh; Sheo Mohan Prasad; Prashant Kumar Singh; Nawal Kishore Dubey; Avinash Chand Pandey; Devendra Kumar ChauhanUnderstanding 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. © 2016 Elsevier Masson SASPublicationReview Toxicity of aluminium on various levels of plant cells and organism: A review(Elsevier B.V., 2017) Shweta Singh; Durgesh Kumar Tripathi; Swati Singh; Shivesh Sharma; Nawal Kishore Dubey; Devendra Kumar Chauhan; Marek VaculíkIndustrial revolution brought prodigious encroachment on agricultural productivity but at apparent environmental costs. One of the major unfortunate consequences of industrialization is soil acidification. In acidic soils, aluminium (Al) is the primary limitation of crop productivity worldwide. Inception of soil acidification (pH < 5) brings solubilisation of toxic forms of Al into the soil solution, where already micromolar concentrations of it inhibit root growth and cause impairment of several other physiological and metabolic functions. Almost 50% of the total world's potentially arable land consists of acidic soils that cause Al toxicity hazard. The problem of Al toxicity has been further aggravated by the use of fertilizers and acid rains. This review provides the current updates of uptake mechanisms, accumulation and subcellular localization of Al in plants, as well as several aspects of Al functioning on various levels of plant organism. © 2017 Elsevier B.V.PublicationArticle LIB spectroscopic and biochemical analysis to characterize lead toxicity alleviative nature of silicon in wheat (Triticum aestivum L.) seedlings(Elsevier B.V., 2016) Durgesh Kumar Tripathi; Vijay Pratap Singh; Sheo Mohan Prasad; Nawal Kishore Dubey; Devendra Kumar Chauhan; Awadesh Kumar RaiThe responses of wheat seedling treated with silicon (Si; 10 μM) and lead (Pb; 100 μM) for 7 days have been investigated by analyzing growth, Pb uptake, chlorophyll fluorescence, oxidative stress, antioxidants and nutrients regulation. Results indicated that, Pb significantly (P < 0.05) declined growth of seedlings which was accompanied by uptake of Pb. Under Pb stress, fluorescence parameters: Fv/Fm ratio and qP were significantly (P < 0.05) decreased while NPQ was increased. Si addition alleviated Pb-induced decrease in growth and alterations in photosynthesis, and also significantly (P < 0.05) lowered Pb uptake. Under Pb treatment, oxidative stress markers: hydrogen peroxide and lipid peroxidation were enhanced while DPPH• scavenging capacity and total phenolic compounds (TPCs) were decreased significantly, however, Si addition improved the status of antioxidants. The non-protein thiols (NP-SH) showed enhanced level under Pb stress. Pb stress considerably disturbed status of the nutrients as decrease in Ca, P, Mg, Zn and Ni contents while an increase in K, S, B, Cu, Fe, Mn and Na contents were noticed. Si addition maintained status of all the nutrients remarkably. The quickest method of element analysis: LIBS spectra revealed significantly lower uptake of Pb in seedlings grown under Si and Pb combination and same was correlated with the data of AAS. Overall results pointed out that excess Pb uptake disturbed status of nutrients, photosynthetic performance, antioxidant capacity, hence severe oxidative damage to lipids occurred. Further, Si supplementation successfully regulated these parameters by inhibiting Pb uptake hence maintained growth of wheat seedlings. Similar pattern of data recorded by the LIBS, AAS and ICAP-AES confirmed that LIBS may be one of the promising and authentic tools to monitor the mineral and metal distribution in the plants without hampering or disturbing the environment due to its eco-friendly and non-invasive nature. © 2015 Elsevier B.V. All rights reserved.PublicationReview An overview on manufactured nanoparticles in plants: Uptake, translocation, accumulation and phytotoxicity(Elsevier Masson SAS, 2017) Durgesh Kumar Tripathi; Shweta; Shweta Singh; Swati Singh; Rishikesh Pandey; Vijay Pratap Singh; Nilesh C. Sharma; Sheo Mohan Prasad; Nawal Kishore Dubey; Devendra Kumar ChauhanThe unprecedented capability to control and characterize materials on the nanometer scale has led to the rapid expansion of nanostructured materials. The expansion of nanotechnology, resulting into myriads of consumer and industrial products, causes a concern among the scientific community regarding risk associated with the release of nanomaterials in the environment. Bioavailability of excess nanomaterials ultimately threatens ecosystem and human health. Over the past few years, the field of nanotoxicology dealing with adverse effects and the probable risk associated with particulate structures <100 nm in size has emerged from the recognized understanding of toxic effects of fibrous and non-fibrous particles and their interactions with plants. The present review summarizes uptake, translocation and accumulation of nanomaterials and their recognized ways of phytotoxicity on morpho-anatomical, physiological, biochemical and molecular traits of plants. Besides this, the present review also examines the intrinsic detoxification mechanisms in plants in light of nanomaterial accumulation within plant cells or parts. © 2016 Elsevier Masson SASPublicationArticle Differential phytotoxic responses of silver nitrate (AgNO3) and silver nanoparticle (AgNps) in Cucumis sativus L.(Elsevier B.V., 2017) Ashutosh Tripathi; Shiliang Liu; Prashant Kumar Singh; Niraj Kumar; Avinash Chandra Pandey; Durgesh Kumar Tripathi; Devendra Kumar Chauhan; Shivendra SahiThe present study was undertaken to evaluate the effects of silver nitrate (AgNO3) and biosynthesized silver nanoparticle (AgNps) on Cucumis sativus L seedlings. Results indicated that both the forms of silver significantly reduced the growth which may be accompanied due to increased accumulation of silver in plants (4708.2 ± 108.75 mg/kg). Both the treatments showed steep reduction (> in AgNO3 treatments) in photosynthetic performance, total chlorophyll, carotenoids and total protein content and significantly (P < 0.05) increased oxidative stress (MDA, H2O2, SOR; i.e. > in AgNO3 treatment). The histochemical observations (NBT & DAB) of oxidative stress markers (H2O2 and O2[rad]−) were also in accordance with their total estimation of H2O2 and O2[rad]− in both the treatments. Chlorophyll florescence parameters were also significantly (P < 0.05) influenced by AgNO3 and AgNps treatments and showed remarkable modifications.Though, both the treatments (AgNO3 and AgNps) showed anatomical impacts on the root cortical cells, however, degeneration of cortical cells and disintegration of endodermis in AgNO3 treatments were more prominent. Taking impacts of the both forms of silver together, present study suggests that the AgNO3 is more toxic than AgNPs while potential risks of both forms is critical on the growth and development of Cucumis seedlings. We suggest further studies to explore the underlying mechanisms and to understand the effective levels of both forms of silver to be used in sustaining agricultural productions. © 2017PublicationBook Chapter Assessment of antioxidant potential of plants in response to heavy metals(Springer Singapore, 2016) Namira Arif; Vaishali Yadav; Shweta Singh; Bishwajit Kumar Kushwaha; Swati Singh; Durgesh Kumar Tripathi; Kanchan Vishwakarma; Shivesh Sharma; N.K. Dubey; D.K. ChauhanHeavy metals (HMs) are consequential environmental contaminant, and their prodigious bioaccumulation in the surroundings has become an enigma for all living organisms including plants. Heavy metal has the potential to react with various indispensable cellular components like DNA, protein, and enzymes and in turn induce several stress responses in plants like oxidative stress which is the root cause for the progression of cell death in the plant. Stress responses inflicted by oxidative stress include severe morphological, metabolic, and physiological amendments in plants like DNA strand breakage, defragmentation of proteins, and damage of photosynthetic pigment, which may stimulate cell death. In reaction, plants have a range of mechanisms to minimize the heavy metal toxicity. Plants are endowed with antioxidant defense mechanism, which can be divided into two groups such as enzymatic antioxidants and nonenzymatic antioxidants, for instance, SOD, CAT, APX, GPX, GR and AsA, GSH, carotenoids, alkaloids, tocopherols, proline, and phenolic compounds, respectively, that together act as the scavengers for free radicals to mitigate the damaging impacts of heavy metal agglomeration in the cells. These antioxidant potentials could be assessed by different in vivo and in vitro methods such as hydrogen atom transfer and electron transfer through which we can evaluate the ROS detrimental action of antioxidant enzymes. Therefore, the present chapter attempts to provide the contemporary knowledge regarding the metal-influenced antioxidant status in plants and also provides the precise pathway that should follow for the future research in the area of antioxidant potentials. © Springer Nature Singapore Pte Ltd. 2016.PublicationArticle Regulation of ascorbate-glutathione cycle by exogenous nitric oxide and hydrogen peroxide in soybean roots under arsenate stress(Elsevier B.V., 2021) Samiksha Singh; Tajammul Husain; Bishwajit Kumar Kushwaha; Mohd. Suhel; Abreeq Fatima; Vipul Mishra; Sani Kumar Singh; Javaid Akhtar Bhatt; Meena Rai; Sheo Mohan Prasad; Nawal Kishore Dubey; Devendra Kumar Chauhan; Durgesh Kumar Tripathi; Vasileios Fotopoulos; Vijay Pratap SinghThe role of nitric oxide (NO) and hydrogen peroxide (H2O2) is well known for regulating plant abiotic stress responses. However, underlying mechanisms are still poorly understood. Therefore, the present study investigated the involvement of NO and H2O2 signalling in the regulation of arsenate toxicity (AsV) in soybean roots employing a pharmacological approach. Results show that AsV toxicity declined root length and biomass due to greater As accumulation in the cell wall and cellular organelles. Arsenate induced cell death due to enhanced levels of reactive oxygen species, lipid and protein oxidation and down-regulation in ascorbate-glutathione cycle and redox states of ascorbate and glutathione. These results correlate with lower endogenous level of NO. Interestingly, addition of L-NAME increased AsV toxicity. However, addition of SNP reverses effect of L-NAME, suggesting that endogenous NO has a role in mitigating AsV toxicity. Exogenous H2O2 also demonstrated capability of alleviating AsV stress, while NAC reversed the protective effect of H2O2. Furthermore, DPI application further increased AsV toxicity, suggesting that endogenous H2O2 is also implicated in mitigating AsV stress. SNP was not able to mitigate AsV toxicity in the presence of DPI, suggesting that H2O2 might have acted downstream of NO in accomplishing amelioration of AsV toxicity. © 2020 Elsevier B.V.