Browsing by Author "Nawal K. Dubey"

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Acquisition and homeostasis of Iron in higher plants and their probable role in abiotic stress tolerance
(Frontiers Media S.A., 2018) Durgesh K. Tripathi; Shweta Singh; Shweta Gaur; Swati Singh; Vaishali Yadav; Shiliang Liu; Vijay P. Singh; Shivesh Sharma; Prateek Srivastava; Sheo M. Prasad; Nawal K. Dubey; Devendra K. Chauhan; Shivendra Sahi
Iron (Fe) is a micronutrient that plays an important role in agriculture worldwide because plants require a small amount of iron for its growth and development. All major functions in a plant's life from chlorophyll biosynthesis to energy transfer are performed by Fe (Brumbarova et al., 2008; Gill and Tuteja, 2011). Iron also acts as a major constituent of many plant proteins and enzymes. The acquisition of Fe in plants occurs through two strategies, i.e., strategy I and strategy II (Marschner and Römheld, 1994). Under various stress conditions, Nramp and the YSL gene families help in translocation of Fe, which further acts as a mineral regulatory element and defends plants against stresses. Iron plays an irreplaceable role in alleviating stress imposed by salinity, drought, and heavy metal stress. This is because it activates plant enzymatic antioxidants like catalase (CAT), peroxidase, and an isoform of superoxide dismutase (SOD) that act as a scavenger of reactive oxygen species (ROS) (Hellin et al., 1995). In addition to this, their deficiency as well as their excess amount can disturb the homeostasis of a plant's cell and result in declining of photosynthetic rate, respiration, and increased accumulation of Na+ and Ca- ions which culminate in an excessive formation of ROS. The short-range order hydrated Fe oxides and organic functional groups show affinities for metal ions. Iron plaque biofilm matrices could sequester a large amount of metals at the soil-root interface. Hence, it has attracted the attention of plant physiologists and agricultural scientists who are discovering more exciting and hidden applications of Fe and its potential in the development of bio-factories. This review looks into the recent progress made in putting forward the role of Fe in plant growth, development, and acclimation under major abiotic stresses, i.e., salinity, drought, and heavy metals. © 2018 Tripathi, Singh, Gaur, Singh, Yadav, Liu, Singh, Sharma, Srivastava, Prasad, Dubey, Chauhan and Sahi.
Assessment of chemically characterised Rosmarinus officinalis L. essential oil and its major compounds as plant-based preservative in food system based on their efficacy against food-borne moulds and aflatoxin secretion and as antioxidant
(2015) Bhanu Prakash; Akash Kedia; Prashant K. Mishra; Abhishek K. Dwivedy; Nawal K. Dubey
The study explores antifungal, anti-aflatoxigenic and antioxidant efficacy of Rosmarinus officinalis essential oil (ROEO) and its major compounds. In addition, the mode of action of ROEO and its practical efficacy as preservative have been assessed. GC-MS analysis of ROEO identified 16 compounds; α-pinene, 1,8-cineole and camphor being the major compounds. The minimum concentration for inhibition of growth and aflatoxin B1 secretion against A. flavus (LHP-6) was found to be 1.5, >5.0, 4.0 and 3.0 μL mL-1 and 1.25, >5.0, 3.5 and 3.0 μL mL-1 for ROEO, α-pinene, 1,8-cineole and camphor, respectively. The IC50 value through DPPH analysis and percentage inhibition of linoleic acid peroxidation of ROEO were 0.042 μL mL-1 and 71.05%, respectively. The targeted site of antifungal action of ROEO was confirmed as plasma membrane through ergosterol measurement and TEM analysis. Moreover, ROEO significantly protected Piper nigrum fruits against mould infestation upto 6 months in in vivo trial. © 2015 Institute of Food Science and Technology.
Assessment of Pelargonium graveolens oil as plant-based antimicrobial and aflatoxin suppressor in food preservation
(2008) Priyanka Singh; Bhawana Srivastava; Ashok Kumar; Rajesh Kumar; Nawal K. Dubey; Rajesh Gupta
BACKGROUND: Contamination of stored food commodities by moulds and mycotoxins results in qualitative as well as quantitative losses. Most of the synthetic antimicrobials used for preservation of stored food items produce side effects in the form of residual and mammalian toxicity. Recently some higher plant products have been recommended as safe alternatives of such synthetic antimicrobials. In the present investigation antifungal efficacy of some essential oils was evaluated against two toxigenic strains of Aspergillus flavus with special reference to the oil of Pelargonium graveolens to investigate its potential to inhibit aflatoxin B1 secretion. RESULTS: Essential oil of P. graveolens exhibited absolute fungitoxicity against both the toxigenic strains of A. flavus. The minimum inhibitory concentration of the oil was found to be 0.75 g L-1 and exhibited a fungistatic nature. It was found superior over the synthetic fungicides tested and exhibited a broad fungitoxic spectrum. The oil showed excellent anti-aflatoxigenic efficacy as it completely inhibited aflatoxin B1 production even at 0.50 g L-1. CONCLUSION: This is the first report on the aflatoxin B1 inhibitory nature of P. graveolens oil. It may be recommended as a novel plant-based antimicrobial as well as aflatoxin B1 suppressor over synthetic preservatives in food protection. © 2008 Society of Chemical Industry.
Chemical composition of Ocimum basilicum L. essential oil and its efficacy as a preservative against fungal and aflatoxin contamination of dry fruits
(2011) Ashok Kumar; Ravindra Shukla; Priyanka Singh; Bhanu Prakash; Nawal K. Dubey
The study presents fungal and aflatoxin contamination of some dry fruits and Ocimum basilicum essential oil (EO) as a plant-based preservative. During mycoflora analysis, 2045 fungal isolates were recorded from dry fruits and 40% isolates of Aspergillus flavus were toxigenic in nature. The EO of O. basilicum exhibited strong fungitoxicity against toxigenic strain of A. flavus. Its minimum inhibitory concentration (MIC) was recorded at 1.0μLml-1, and it completely inhibited aflatoxin B1 production at 0.5μLml-1. The oil exhibited broad fungitoxic spectrum and considerably reduced A. flavus isolates from dry fruits when used as fumigant in closed storage containers at 1.0μLml-1. The chemical profile of the EO was standardised through GC-MS analysis. Based on antifungal potency, antiaflatoxigenicity and efficacy as fumigant during storage conditions, O. basilicum EO may be recommended as a botanical preservative for enhancing the shelf life of dry fruits and edible products during storage. © 2011 The Authors. International Journal of Food Science and Technology © 2011 Institute of Food Science and Technology.
Common Toxic Plants and Their Forensic Significance
(Elsevier, 2018) Nawal K. Dubey; Abhishek K. Dwivedy; Anand K. Chaudhari; Somenath Das
There are several species of plants that are poisonous to humans. Toxins are metabolites produced by plants to defend themselves against threats. The major poisonous principles present in plants are organic compounds such as alkaloids, diterpenes, flavonoids, tannins, cardiac and cyanogenic glycosides, proanthocyanidins, phenylpropanoids, lignans, nitrogen-containing compounds, resins, oxalates, and certain proteins or amino acids. The nature of these toxic secondary metabolites changes with varying place of origin and environmental conditions. In addition to human toxicity, poisonous plants have been reported to cause death of livestock, deterioration in their health, decreased productivity, deformed offspring, and reduced longevity leading to tremendous economic losses. Toxic plants are of forensic significance, providing evidence in suicidal, criminal, burglary, and other criminal offences. In spite of their adverse effects on humans and other animals, some poisonous plants have medicinal and nutraceutical potential and can cure certain life-threatening diseases. This chapter deals with common poisonous plants in India, poisonous principles, and forensic significance. © 2018 Elsevier Ltd. All rights reserved.
Efficacy of Acorus calamus L. essential oil as a safe plant-based antioxidant, Aflatoxin B1 suppressor and broad spectrum antimicrobial against food-infesting fungi
(2013) Ravindra Shukla; Priyanka Singh; Bhanu Prakash; Nawal K. Dubey
Summary: The study explores the efficacy of Acorus calamus L. essential oil (EO) as a safe plant-based broad spectrum antifungal, antiaflatoxin, antioxidant food additive. The oil completely inhibited the growth and toxin production of the toxigenic strain of Aspergillus flavus at 0.4 and 0.25 μL mL-1, respectively. EO exhibited pronounced antifungal activity against sixteen food-infesting fungal species at 0.5 μL mL-1. The EO showed strong antioxidant efficacy (IC50 1.06 μL mL-1) and nonphytotoxic nature on germination of chickpea seeds. The EO was found nonmammalian toxic showing high LD50 (4877.4 μL kg-1) for mice (oral, acute). The chemical profile of EO was determined through GC and GC-MS analysis. The findings strengthen the possibility of A. calamus EO as a plant-based food additive in view of its favourable safety profile, antioxidant and antiaflatoxigenic efficacy and broad spectrum antimicrobial activity against food-infesting fungi. © 2012 The Authors. International Journal of Food Science and Technology © 2012 Institute of Food Science and Technology.
Efficacy of extract and essential oil of Lantana indica Roxb. against food contaminating moulds and aflatoxin B1 production
(2010) Ashok Kumar; Ravindra Shukla; Priyanka Singh; Anuradha; Nawal K. Dubey
The study investigates the antifungal and antiaflatoxigenic efficacy of Lantana indica against Aspergillus flavus, a key storage fungus. The leaf essential oil of L. indica was found more active than leaf extracts. The oil absolutely inhibited the growth of A. flavus at 1.5 mg mL-1 while ethanolic and chloroform extracts of leaf show MIC at 7.5 and 10.0 mg mL -1 concentrations respectively. The oil also showed pronounced antiaflatoxigenic efficacy and completely inhibited the aflatoxin B1 production at 0.75 mg mL-1. The ethanolic and chloroformic extracts inhibited the aflatoxin B1 production at 5.0 and 7.5 mg mL -1, respectively while other extracts exhibited poor efficacy. The L. indica essential oil exhibited broad fungitoxic spectrum against twelve different storage moulds. The present findings may recommend the L. indica essential oil and its bioactive leaf extracts as natural preservative would of immense significance in view of the environmental and toxicological implications by indiscriminate use of synthetic pesticides. © Institute of Food Science and Technology.
Evaluation of chemically characterised essential oils of Coleus aromaticus, Hyptis suaveolens and Ageratum conyzoides against storage fungi and aflatoxin contamination of food commodities
(2011) S. Jaya; Bhanu Prakash; Nawal K. Dubey
The result of the present investigation explores the efficacy of chemically characterised essential oils (EOs) of Coleus aromaticus, Hyptis suaveolens and Ageratum conyzoides as antifungal and antiaflatoxigenic agent against some storage fungi and the toxigenic strain of Aspergillus flavus (Saktiman 3NSt). Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of these EOs were also determined against the toxigenic strain of A. flavus (Saktiman 3NSt). The EO from C. aromaticus was found to be most effective exhibiting MIC and MFC at 0.1μLmL-1. The EOs also completely checked aflatoxin B1 synthesis in concentration-dependent manner. In addition, fumigation of stored wheat samples with EOs exhibited remarkable protection (>80%) from fungal infestation showing their efficacy during in vivo storage conditions. Based on the results of the present investigation, the EOs of C. aromaticus, H. suaveolens and A. conyzoides may be recommended as novel plant-based antifungal and aflatoxin B1 suppressor over the synthetic preservatives. © 2011 The Authors. International Journal of Food Science and Technology © 2011 Institute of Food Science and Technology.
Evaluation of some essential oils as botanical fungitoxicants for the protection of stored food commodities from fungal infestation
(2007) Rajesh Kumar; Nawal K. Dubey; Om P. Tiwari; Yamini B. Tripathi; Kauskal K. Sinha
Essential oils from different parts of 18 plants belonging to 11 families were extracted and tested against two toxigenic strains of Aspergillus flavus Link through the poisoned food technique. The oil of Mentha arvensis was found to be effective against both strains of A. flavus and completely stopped the radial mycelial growth of A. flavus at 0.10 mg mL-1. It was found to be superior over the synthetic fungicides tested and showed a broad fungitoxic spectrum against A. niger, A. fumigatus, Botryodiplodia theobromae, Cladosporium cladosporioides, Fusarium oxysporum, Helminthosporium oryzae, Macrophomina phaseolina and Sclerotium rolfsii at 0.10 mg mL-1. The oil completely inhibited the aflatoxin B1 production by the toxigenic strain of A. flavus at 0.05 mg mL-1. Moreover, the Mentha oil also exhibited potent antioxidant activity in 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphuric acid (ABTS) bioassay. Keeping in mind the side effects of synthetic pesticides and the global interest in botanical pesticides for plant protection due to their biodegradable nature, M. arvensis oil may be used as a botanical fungitoxicant against fungal attack to stored food commodities. The antiaflatoxigenic and antioxidant nature of the oil suggest the possibility of its exploitation for enhancing the shelf life of stored food commodities. © 2007 Society of Chemical Industry.
Fungal diversity notes 1512–1610: taxonomic and phylogenetic contributions on genera and species of fungal taxa
(Institute for Ionics, 2022) Ruvishika S. Jayawardena; Kevin D. Hyde; Song Wang; Ya-Ru Sun; Nakarin Suwannarach; Phongeun Sysouphanthong; Mohamed A. Abdel-Wahab; Faten A. Abdel-Aziz; Pranami D. Abeywickrama; Vanessa P. Abreu; Alireza Armand; André Aptroot; Dan-Feng Bao; Dominik Begerow; Jean-Michel Bellanger; Jadson D. P. Bezerra; Digvijayini Bundhun; Mark S. Calabon; Ting Cao; Taimy Cantillo; João L. V. R. Carvalho; Napalai Chaiwan; Che-Chih Chen; Régis Courtecuisse; Bao-Kai Cui; Ulrike Damm; Cvetomir M. Denchev; Teodor T. Denchev; Chun Y. Deng; Bandarupalli Devadatha; Nimali I. de Silva; Lidiane A. dos Santos; Nawal K. Dubey; Sylvain Dumez; Himashi S. Ferdinandez; André L. Firmino; Yusufjon Gafforov; Achala J. Gajanayake; Deecksha Gomdola; Sugantha Gunaseelan; Shucheng-He; Zin H. Htet; Malarvizhi Kaliyaperumal; Martin Kemler; Kezhocuyi Kezo; Nuwan D. Kularathnage; Marco Leonardi; Ji-Peng Li; Chunfang Liao; Shun Liu; Michael Loizides; Thatsanee Luangharn; Jian Ma; Hugo Madrid; S. Mahadevakumar; Sajeewa S. N. Maharachchikumbura; Dimuthu S. Manamgoda; María P. Martín; Niranjan Mekala; Pierre-Arthur Moreau; Yan-Hong Mu; Pasouvang Pahoua; Dhandevi Pem; Olinto L. Pereira; Wiphawanee Phonrob; Chayanard Phukhamsakda; Mubashar Raza; Guang-Cong Ren; Andrea C. Rinaldi; Walter Rossi; Binu C. Samarakoon; Milan C. Samarakoon; Vemuri V. Sarma; Indunil C. Senanayake; Archana Singh; Maria F. Souza; Cristina M. Souza-Motta; Adriano A. Spielmann; Wenxin Su; Xia Tang; XingGuo Tian; Kasun M. Thambugala; Naritsada Thongklang; Danushka S. Tennakoon; Nopparat Wannathes; DingPeng Wei; Stéphane Welti; Subodini N. Wijesinghe; Hongde Yang; Yunhui Yang; Hai-Sheng Yuan; Huang Zhang; Jingyi Zhang; Abhaya Balasuriya; Chitrabhanu S. Bhunjun; Timur S. Bulgakov; Lei Cai; Erio Camporesi; Putarak Chomnunti; Y.S. Deepika; Mingkwan Doilom; Wei-Jun Duan; Shi-Ling Han; Naruemon Huanraluek; E. B. Gareth Jones; N. Lakshmidevi; Yu Li; Saisamorn Lumyong; Zong-Long Luo; Surapong Khuna; Jaturong Kumla; Ishara S. Manawasinghe; Ausana Mapook; Wilawan Punyaboon; Saowaluck Tibpromma; Yong-Zhong Lu; JiYe Yan; Yong Wang
This article is the 14th in the Fungal Diversity Notes series, wherein we report 98 taxa distributed in two phyla, seven classes, 26 orders and 50 families which are described and illustrated. Taxa in this study were collected from Australia, Brazil, Burkina Faso, Chile, China, Cyprus, Egypt, France, French Guiana, India, Indonesia, Italy, Laos, Mexico, Russia, Sri Lanka, Thailand, and Vietnam. There are 59 new taxa, 39 new hosts and new geographical distributions with one new combination. The 59 new species comprise Angustimassarinakunmingense, Asterinalopi, Asterinabrigadeirensis, Bartaliniabidenticola, Bartaliniacaryotae, Buelliapruinocalcarea, Coltriciainsularis, Colletotrichumflexuosum, Colletotrichumthasutense, Coniochaetacaraganae, Coniothyriumyuccicola, Dematipyriformaaquatic, Dematipyriformaglobispora, Dematipyriformanilotica, Distoseptisporabambusicola, Fulvifomesjawadhuvensis, Fulvifomesmalaiyanurensis, Fulvifomesthiruvannamalaiensis, Fusariumpurpurea, Gerronemaatrovirens, Gerronemaflavum, Gerronemakeralense, Gerronemakuruvense, Grammotheletaiwanensis, Hongkongmyceschangchunensis, Hypoxyloninaequale, Kirschsteiniotheliaacutisporum, Kirschsteiniotheliacrustaceum, Kirschsteiniotheliaextensum, Kirschsteiniotheliaseptemseptatum, Kirschsteiniotheliaspatiosum, Lecanoraimmersocalcarea, Lepiotasubthailandica, Lindgomycesguizhouensis, Martheasmiuspallidoaurantiacus, Marasmiustangerinus, Neovaginatisporamangiferae, Pararamichloridiumaquisubtropicum, Pestalotiopsispiraubensis, Phacidiumchinaum, Phaeoisariagoiasensis, Phaeoseptumthailandicum, Pleurotheciumaquisubtropicum, Pseudocercosporavernoniae, Pyrenophoraverruculosa, Rhachomycescruralis, Rhachomyceshyperommae, Rhachomycesmagrinii, Rhachomycesplatyprosophi, Rhizomarasmiuscunninghamietorum, Skeletocutiscangshanensis, Skeletocutissubchrysella, Sporisoriumanadelphiae-leptocomae, Tetraploadashaoensis, Tomentellaexiguelata, Tomentellafuscoaraneosa, Tricholomopsislechatii, Vaginatisporaflavispora and Wetmoreanablastidiocalcarea. The new combination is Torulasundara. The 39 new records on hosts and geographical distribution comprise Apiosporaguiyangensis, Aplosporellaartocarpi, Ascochytamedicaginicola, Astrocystisbambusicola, Atheliarolfsii, Bambusicolabambusae, Bipolarisluttrellii, Botryosphaeriadothidea, Chlorophyllumsquamulosum, Colletotrichumaeschynomenes, Colletotrichumpandanicola, Coprinopsiscinerea, Corylicolaitalica, Curvulariaalcornii, Curvulariasenegalensis, Diaporthefoeniculina, Diaporthelongicolla, Diaporthephaseolorum, Diatrypellaquercina, Fusariumbrachygibbosum, Helicomaaquaticum, Lepiotametulispora, Lepiotapongduadensis, Lepiotasubvenenata, Melanconiellameridionalis, Monotosporellaerecta, Nodulosphaeriadigitalis, Palmiascomagregariascomum, Periconiabyssoides, Periconiacortaderiae, Pleopunctumellipsoideum, Psilocybekeralensis, Scedosporiumapiospermum, Scedosporiumdehoogii, Scedosporiummarina, Spegazziniadeightonii, Torulafici, Wiesneriomyceslaurinus and Xylariavenosula. All these taxa are supported by morphological and multigene phylogenetic analyses. This article allows the researchers to publish fungal collections which are important for future studies. An updated, accurate and timely report of fungus-host and fungus-geography is important. We also provide an updated list of fungal taxa published in the previous fungal diversity notes. In this list, erroneous taxa and synonyms are marked and corrected accordingly. © 2023, The Author(s) under exclusive licence to Mushroom Research Foundation.
Fungal mycotoxins in food commodities: present status and future concerns
(Frontiers Media S.A., 2023) Abhay K. Pandey; Mahesh K. Samota; Abhishek Kumar; Ana Sanches Silva; Nawal K. Dubey
Mycotoxins are toxic secondary metabolites produced by fungi when they colonies the foodstuffs. These are potent toxins having severe health consequences in people, being mutagenic, teratogenic, and carcinogenic. In agricultural commodities, the contamination of mycotoxins is more prevalent. Several fungi can produce mycotoxins on agricultural products during harvest or in postharvest, and they have significant adverse effects on both animal and human beings. The most prevalent mycotoxins found in food commodities are aflatoxins and ochratoxins produced by Aspergillus species, ochratoxins and patulin produced by Penicillium, as well as fumonisins, deoxynivalenol, and zearalenone produced by Fusarium species. Worldwide, fumonisins, patulin, aflatoxins, and ochratoxins, among others, are responsible for numerous acute and chronic diseases in people and domestic animals. In food commodities, mycotoxins have been quantified and detected using various analytical methods. Besides, mycotoxins occurrence in food commodities were decontaminated through many potential approaches, such as physical, chemical, and biological methods. This review summarizes the findings of 30 years of research into mycotoxins in major commercial food crops including wheat, maize, sorghum, pearl millet, peanut, oat, pulses, barley, oilseeds, rice, and fruits and fruit juices. We also discuss the detection methods of major mycotoxins, available decontamination strategies along with their disadvantages and knowledge gaps. It is anticipated that data from meticulous studies on mycotoxins in food commodities will help in the development of safer food and in setting priorities for future research. Copyright © 2023 Pandey, Samota, Kumar, Silva and Dubey.
Global scenario on the application of natural products in integrated pest management programmes
(CABI Publishing, 2010) Nawal K. Dubey; Ravindra Shukla; Ashok Kumar; Priyanka Singh; Bhanu Prakash
In recent years there has been considerable pressure in agriculture to reduce chemical pesticides and to look for their better alternatives. The plant kingdom is recognized as the most effi cient producer of different biologically active compounds, which provide them with resistance against different pests. Some higher plant products have been currently formulated as botanical pesticides and are used on a large scale as ecofriendly and biodegradable measures in managing agricultural pests. Botanicals used in agricultural pest management are safer to the user and the environment. The interest in the possible use of natural compounds to control agricultural pests has notably increased in response to consumer pressure to reduce or eliminate chemically synthesized additives in foods. There is a wide scope of use of plant-based pesticides in the integrated management of different agricultural pests. A consolidated and continuous search of natural products may yield safer alternative control measures comparable to azadirachtin and pyrethryoids, which are being used in different part of the world as ideal natural fungicides. The products from higher plants are safe and economical and would be in high demand in the global pesticide market because of their diverse mode of application. © CAB International 2011. All rights reserved.
Green synthesis, characterization and biological activity of synthesized ruthenium nanoparticles using fishtail fern, sago palm, rosy periwinkle and holy basil
(Indian Academy of Sciences, 2019) Pranshu K. Gupta; Kalluri V.S. Ranganath; Nawal K. Dubey; Lallan Mishra
Ruthenium nanoparticles (Ru NPs) of different sizes prepared using leaf extracts of fishtail fern (Nephrole-pis biserrata), sago palm (Cycas revoluta), rosy periwinkle (Catharanthus roseus) and holy basil (Oci-mum tenuiflorum) in methanol exhibited pronounced antifungal (against Aspergillus flavus) and antioxidant activity (DPPH, ABTS, SO, OH). The synthesized Ru NPs were characterized using FTIR, UV-visible spectra, fluorescence and XRD. A tentative synthetic mechanism of NPs has been hypothesized via redox mechanism. A correlation between size of nano-particles and plant groups has also been established. © 2019, Indian Academy of Sciences.
Nanoencapsulated Lippia origanoides essential oil: physiochemical characterisation and assessment of its bio-efficacy against fungal and aflatoxin contamination as novel green preservative
(John Wiley and Sons Inc, 2022) Shikha Tiwari; Neha Upadhyay; Bijendra Kumar Singh; Nawal K. Dubey; Abhishek K. Dwivedy; Vipin Kumar Singh
The study explores in vitro antifungal and aflatoxin B1 inhibitory potency of chemically characterised Lippia origanoides EO (LOEO) encompassed in chitosan nanoparticle (CS-LOEO-Np). CS-LOEO-Np was physico-chemically characterised through XRD, SEM and FTIR analyses. CS-LOEO-Np exhibited improved antifungal and AFB1 inhibitory efficacy (0.05 and 0.045 µl mL−1, respectively) in contrast to LOEO (0.30 and 0.25 µl mL−1, respectively). Bioactivity of LOEO loaded nanoparticle was enhanced as reflected by depletion in ergosterol content, rapid cellular ion release and reduced methylglyoxal content. IC50 value equivalent to 4.17 µl mL−1 displayed better antioxidant potency of CS-LOEO-Np as compared to LOEO (IC50 = 6.20 µl mL−1). CS-LOEO-Np preserved sensorial attributes of stored Nigella sativa (model food matrix) samples and have higher lethal toxicity dose, that is LD50 = 8832 mg kg−1. Hence, CS-LOEO-Np could serve as novel green candidate to ensure food security with better nutritional and sensorial features. © 2022 Institute of Food Science and Technology
Natural products in plant pest management
(CABI Publishing, 2010) Nawal K. Dubey
Overzealous and indiscriminate use of many synthetic pesticides during recent decades in the control of plant pests has resulted in a number of environmental and toxicological problems. Reducing the release of synthetic chemicals into the environment requires that alternative sources of chemicals are developed that can be used safely in the management of plant pests. Botanical antimicrobials derived from plants are currently recognised as biodegradable, systemic, eco-friendly and non-toxic to mammals and are thus considered safe. Their modes of action against pests are diverse. Natural compounds are well suited to organic food production in industrialised countries and can play greater roles in the protection of food crops in developing countries Some plant based antimicrobials (e.g. neem products, pyrethoids and essential oils) are already used to manage pest populations on a large scale. Plant scientists and agriculturists now devote significant attention to discovery and further development and formulation of novel plant products with antimicrobial activity. This book is the first to bring together relevant aspects of the basic and applied sciences of natural pesticides and discussed modern trends in the use of natural products in pest management. © CAB International 2011. All rights reserved.
Nitric oxide ameliorates zinc oxide nanoparticles phytotoxicity in wheat seedlings: Implication of the ascorbate–glutathione cycle
(Frontiers Media S.A., 2017) Durgesh K. Tripathi; Rohit K. Mishra; Swati Singh; Samiksha Singh; Kanchan Vishwakarma; Shivesh Sharma; Vijay P. Singh; Prashant K. Singh; Sheo M. Prasad; Nawal K. Dubey; Avinash C. Pandey; Shivendra Sahi; Devendra K. Chauhan
The present study investigates ameliorative effects of nitric oxide (NO) against zinc oxide nanoparticles (ZnONPs) phytotoxicity in wheat seedlings. ZnONPs exposure hampered growth of wheat seedlings, which coincided with reduced photosynthetic efficiency (Fv/Fm and qP), due to increased accumulation of zinc (Zn) in xylem and phloem saps. However, SNP supplementation partially mitigated the ZnONPs-mediated toxicity through the modulation of photosynthetic activity and Zn accumulation in xylem and phloem saps. Further, the results reveal that ZnONPs treatments enhanced levels of hydrogen peroxide and lipid peroxidation (as malondialdehyde; MDA) due to severely inhibited activities of the following ascorbate–glutatione cycle (AsA–GSH) enzymes: ascorbate peroxidase, glutathione reductase, monodehydroascorbate reductase and dehydroascorbate reductase, and its associated metabolites ascorbate and glutathione. In contrast to this, the addition of SNP together with ZnONPs maintained the cellular functioning of the AsA–GSH cycle properly, hence lesser damage was noticed in comparison to ZnONPs treatments alone. The protective effect of SNP against ZnONPs toxicity on fresh weight (growth) can be reversed by 2-(4carboxy-2-phenyl)-4,4,5,5-tetramethyl- imidazoline-1-oxyl-3-oxide, a NO scavenger, and thus suggesting that NO released from SNP ameliorates ZnONPs toxicity. Overall, the results of the present study have shown the role of NO in the reducing of ZnONPs toxicity through the regulation of accumulation of Zn as well as the functioning of the AsA–GSH cycle. © 2017 Tripathi, Mishra, Singh, Singh, Vishwakarma, Sharma, Singh, Singh, Prasad, Dubey, Pandey, Sahi and Chauhan.
Phytochemicals as an Eco-Friendly Source for Sustainable Management of Soil-Borne Plant Pathogens in Soil Ecosystem
(wiley, 2023) Shikha Tiwari; Nawal K. Dubey; Chitranjan Kumar
A huge amount of crops are lost due to soil-borne pests. Indiscriminate application of synthetic pesticides has been frequently reported to impose adverse effects on health and the soil environment. In this context, the application of plant-based green chemicals has been highly encouraged in recent years to manage soil-borne agricultural pests sustainably. Despite having advantageous roles as eco-friendly, safer, and efficacious pesticides; large-scale applicability of botanical products as green pesticides in soil ecosystem is still having some challenges based on their high susceptibility toward environmental conditions and volatility. These limitations can be resolved via the incorporation of the nanoencapsulation approach. The present chapter discusses the role of plant-based green pesticides as a novel promising source to combat soil-borne pests and enhance agricultural production sustainably with special reference to the contribution of the nanotechnological approach as a future sustainable dimension for green pesticides. © 2023 John Wiley & Sons Ltd.
Preface
(CABI Publishing, 2010) Nawal K. Dubey
[No abstract available]
Ultrasound enhanced sanitizer efficacy in reduction of escherichia coli o157:h7 population on spinach leaves
(2009) Priyanka Singh; Ashok Kumar; Nawal K. Dubey; Rajesh Gupta
The use of ultrasound to enhance the efficacy of selected sanitizers in reduction of Escherichia coli O157 :H7 populations on spinach was investigated. Spot-inoculated spinach samples were treated with water, chlorine, acidified sodium chlorite (ASC), peroxyacetic acid (POAA), and acidic electrolyzed water with and without ultrasound (21.2 kHz) for 2 min at room temperature. The effects of ultrasound treatment time and acoustic energy density (AED)were evaluated at an ASC concentration of 200 mg/L. The effect of ASC concentration,with a fixed AEDof 200 W/L, was also examined.Microbial analysis indicated that ASC reduced E. coli O157 :H7 population by 2.2 log cycles over that of water wash, while the reduction from other sanitizers was about 1 log cycle. Ultrasonication significantly enhanced the reduction of E. coli cells on spinach for all treatments by 0.7 to 1.1 log cycle over that of washes with sanitizer alone. An increase in the ASC concentration enhanced the efficacy of the combined treatment of ASC and ultrasonication, especially at ASC concentrations of < 300 mg/L. Increasing the ultrasound treatment time from 0 to 4 min and AED from 0 to 500 W/L were both effective in increasing the effectiveness of the ASC and ultrasound combined treatments. In addition, E. coli O157 :H7 inoculated on the underside of spinach leaves (rough side) weremore difficult to remove than those inoculated on the upper side (smooth side). © 2009 Institute of Food Technologists.
Uptake, accumulation and toxicity of silver nanoparticle in autotrophic plants, and heterotrophic microbes: A concentric review
(Frontiers Media S.A., 2017) Durgesh K. Tripathi; Ashutosh Tripathi; Shweta; Swati Singh; Yashwant Singh; Kanchan Vishwakarma; Gaurav Yadav; Shivesh Sharma; Vivek K. Singh; Rohit K. Mishra; R.G. Upadhyay; Nawal K. Dubey; Yonghoon Lee; Devendra K. Chauhan
Nanotechnology is a cutting-edge field of science with the potential to revolutionize today's technological advances including industrial applications. It is being utilized for the welfare of mankind; but at the same time, the unprecedented use and uncontrolled release of nanomaterials into the environment poses enormous threat to living organisms. Silver nanoparticles (AgNPs) are used in several industries and its continuous release may hamper many physiological and biochemical processes in the living organisms including autotrophs and heterotrophs. The present review gives a concentric know-how of the effects of AgNPs on the lower and higher autotrophic plants as well as on heterotrophic microbes so as to have better understanding of the differences in effects among these two groups. It also focuses on the mechanism of uptake, translocation, accumulation in the plants and microbes, and resulting toxicity as well as tolerance mechanisms by which these microorganisms are able to survive and reduce the effects of AgNPs. This review differentiates the impact of silver nanoparticles at various levels between autotrophs and heterotrophs and signifies the prevailing tolerance mechanisms. With this background, a comprehensive idea can be made with respect to the influence of AgNPs on lower and higher autotrophic plants together with heterotrophic microbes and new insights can be generated for the researchers to understand the toxicity and tolerance mechanisms of AgNPs in plants and microbes. © 2017 Tripathi, Tripathi, Shweta, Singh, Singh, Vishwakarma, Yadav, Sharma, Singh, Mishra, Upadhyay, Dubey, Lee and Chauhan.