Browsing by Author "Mukesh Meena"

Now showing 1 - 20 of 54

A review on phytotoxicity and defense mechanism of silver nanoparticles (AgNPs) on plants
(Springer Science and Business Media B.V., 2023) Sumit Kumar; Prahlad Masurkar; Bana Sravani; Dipanjali Bag; Kamal Ravi Sharma; Prashant Singh; Tulasi Korra; Mukesh Meena; Prashant Swapnil; Vishnu D. Rajput; Tatiana Minkina
Silver nanoparticles (AgNPs) are noteworthy used nanomaterials in a wide array of fields, particularly in the agricultural sector. Plants play a multifarious role in the ecosystem and provide a source of food for mankind. The responsibility of the scientific community is to recognize the deleterious impact of AgNPs (1–100 nm in size) on critical crop growth and development of plants, which is required for the assessment of environmental threats to plant, human, and animal health. The continued use of AgNPs in agriculture areas may have negative effects on plant biochemical and physiological responses. The current context focused mainly on AgNPs uptake, transport, and accumulation on crop plants and summarizes different levels of phytotoxicity of AgNPs on plant functions and focused on mechanisms of phytotoxicity employed by AgNPs. Moreover, some tolerance mechanisms and various survival strategies developed by plants under AgNPs toxicity are discussed. This background provides comprehensive information necessary to facilitate profound understanding of the toxic impacts of AgNPs on crop plants. © 2023, The Author(s), under exclusive licence to Springer Nature B.V.
Activation of defense response in tomato against Fusarium wilt disease triggered by Trichoderma harzianum supplemented with exogenous chemical inducers (SA and MeJA)
(Springer International Publishing, 2017) Andleeb Zehra; Mukesh Meena; Manish Kumar Dubey; Mohd. Aamir; R.S. Upadhyay
The use of soil bioagent along with chemical inducers in controlling plant diseases is a unique strategy. The exogenous application of some chemical inducers such as salicylic acid (SA) or methyl jasmonate (MeJA) provides resistance to combat plant pathogens. The intrinsic mechanism that leads into the enhanced defense mechanism by using biological microorganisms, however, correlates with the signaling pathways involving these chemical inducers. In the present study, we have evaluated the biochemical changes relevant to defense activities when plants were pretreated with bioagent, Trichoderma harzianum (Th) and chemical inducers (SA and/or MeJA) and challenged by wilt pathogen Fusarium oxysporum f. sp. lycopersici. We have also evaluated the combined effect of biological (Th) and chemical inducers (SA and/or MeJA) pretreatment followed by pathogen exposure on the biochemical defense-related parameters in tomato. We found that the combined application of Trichoderma along with SA and MeJA provided a better strategy for controlling wilt pathogen rather than using bioagent and chemical inducers alone. The defense-related proteins and phenolics were found to be increased several folds at different time intervals following the combined treatment of biological and chemical inducers compared to when treatment was given alone with bioagent and chemical inducers. The activation of the phenylpropanoid pathway and accumulation of total phenolics were found to be highest at 48 h, whereas the activities of defense-related enzymes and PR proteins along with proline, were found to be maximum at 72 h. The activities of phenolics were also maximum at 48 h, and the activities of PR proteins and proline were higher at 72 h in all single treatments. However, the defense-related activities were greater in combined treatment compared to all single pretreated samples. Therefore, the combined pretreatment with bioagent and chemical inducers triggered the more aggressive defense responses when compared to single treatments and provided better protection against Fusarium wilt. © 2017, Botanical Society of Sao Paulo.
Advantageous features of plant growth-promoting microorganisms to improve plant growth in difficult conditions
(Elsevier, 2023) Mukesh Meena; Garima Yadav; Priyankaraj Sonigra; Adhishree Nagda; Tushar Mehta; Prashant Swapnil; Avinash Marwal; Andleeb Zehra
Microbes play a fundamental role in plant growth and development. The valuable microbes, also known as plant growth-promoting microorganisms (PGPMs) belong to different groups such as fungi, bacteria, and archaea which are connected with plants in rhizospheric, epiphytic, and endophytic forms. These microorganisms display a group of function to promote plant growth such as phytohormone (auxin and gibberellin) production enhancement, siderophore production, micronutrient solubilization (P, K, Fe, and Zn), N2 fixation, antibiotic production, etc. Apart from growth promotion, PGPMs also confer stress and disease tolerance to plants for controlled agricultural production in harsh environmental conditions. PGPMs have the capability to induce systemic resistance (ISR) in crops against pathogen attack. To date, a huge number of microbial species have been documented for their plant growth-promoting ability. Generally, crops fail to provide adequate concentration of micronutrients in the human diet and cause micronutrient malnutrition and severe health complications. Considering all these points, PGPMs are utilized as biofertilizers to increase vigor and the nutrient value of crop plants at varied habitats. The present chapter is intended to focus the ability of PGPMs to perk up the plant growth in difficult conditions. © 2023 Elsevier Inc. All rights reserved.
Alternaria host-specific (HSTs) toxins: An overview of chemical characterization, target sites, regulation and their toxic effects
(Elsevier Inc., 2019) Mukesh Meena; Swarnmala Samal
Alternaria causes pathogenic disease on various economically important crops having saprophytic to endophytic lifecycle. Pathogenic fungi of Alternaria species produce many primary and secondary metabolites (SMs). Alternaria species produce more than 70 mycotoxins. Several species of Alternaria produce various phytotoxins that are host-specific (HSTs) and non-host-specific (nHSTs). These toxins have various negative impacts on cell organelles including chloroplast, mitochondria, plasma membrane, nucleus, Golgi bodies, etc. Non-host-specific toxins such as tentoxin (TEN), Alternaric acid, alternariol (AOH), alternariol 9-monomethyl ether (AME), brefeldin A (dehydro-), Alternuene (ALT), Altertoxin-I, Altertoxin-II, Altertoxin-III, zinniol, tenuazonic acid (TeA), curvularin and alterotoxin (ATX) I, II, III are known toxins produced by Alternaria species. In other hand, Alternaria species produce numerous HSTs such as AK-, AF-, ACT-, AM-, AAL- and ACR-toxin, maculosin, destruxin A, B, etc. are host-specific and classified into different family groups. These mycotoxins are low molecular weight secondary metabolites with various chemical structures. All the HSTs have different mode of actions, biochemical reactions, and signaling mechanisms to causes diseases in the host plants. These HSTs have devastating effects on host plant tissues by affecting biochemical and genetic modifications. Host-specific mycotoxins such as AK-toxin, AF-toxin, and AC-toxin have the devastating effect on plants which causes DNA breakage, cytotoxic, apoptotic cell death, interrupting plant physiology by mitochondrial oxidative phosphorylation and affect membrane permeability. This article will elucidate an understanding of the disease mechanism caused by several Alternaria HSTs on host plants and also the pathways of the toxins and how they caused disease in plants. © 2019 The Authors
Alternaria toxins: Potential virulence factors and genes related to pathogenesis
(Frontiers Media S.A., 2017) Mukesh Meena; Sanjay K. Gupta; Prashant Swapnil; Andleeb Zehra; Manish K. Dubey; Ram S. Upadhyay
Alternaria is an important fungus to study due to their different life style from saprophytes to endophytes and a very successful fungal pathogen that causes diseases to a number of economically important crops. Alternaria species have been well-characterized for the production of different host-specific toxins (HSTs) and non-host specific toxins (nHSTs) which depend upon their physiological and morphological stages. The pathogenicity of Alternaria species depends on host susceptibility or resistance as well as quantitative production of HSTs and nHSTs. These toxins are chemically low molecular weight secondary metabolites (SMs). The effects of toxins are mainly on different parts of cells like mitochondria, chloroplast, plasma membrane, Golgi complex, nucleus, etc. Alternaria species produce several nHSTs such as brefeldin A, tenuazonic acid, tentoxin, and zinniol. HSTs that act in very low concentrations affect only certain plant varieties or genotype and play a role in determining the host range of specificity of plant pathogens. The commonly known HSTs are AAL-, AK-, AM-, AF-, ACR-, and ACTtoxins which are named by their host specificity and these toxins are classified into different family groups. The HSTs are differentiated on the basis of bio-statistical and other molecular analyses. All these toxins have different mode of action, biochemical reactions and signaling mechanisms to cause diseases. Different species of Alternaria produced toxins which reveal its biochemical and genetic effects on itself as well as on its host cells tissues. The genes responsible for the production of HSTs are found on the conditionally dispensable chromosomes (CDCs) which have been well characterized. Different bio-statistical methods like basic local alignment search tool (BLAST) data analysis used for the annotation of gene prediction, pathogenicity-related genes may provide surprising knowledge in present and future. © 2017 Meena, Gupta, Swapnil, Zehra, Dubey and Upadhyay.
Antagonistic assessment of Trichoderma spp. by producing volatile and non-volatile compounds against different fungal pathogens
(Taylor and Francis Ltd., 2017) Mukesh Meena; Prashant Swapnil; Andleeb Zehra; Manish Kumar Dubey; R.S. Upadhyay
Trichoderma spp. are well-known biological agents that have significant antagonistic activity against several plant pathogenic fungi. In the present study, Trichoderma spp. were tested in vitro for their antagonistic activity against different spp. of Fusarium and Alternaria viz. Alternaria alternata, A. brassicae, A. solani, Fusarium oxysporum and F. solani using dual plate assay and by the production of volatile and non-volatile compounds. The results obtained revealed that Trichoderma harzianum and T. viride effectively inhibited the growth and spore production of different spp. of Fusarium and Alternaria. The highest growth inhibition was found in A. alternata 62.50% and 60.00% by non-volatile compounds of T. harzianum and T. viride, respectively. Similarly, the volatile compounds inhibit the maximum growth of A. alternata 40.00% and 35.00% by T. harzianum and T. viride, respectively. Volatile and non-volatile compounds of Trichoderma spp. were analysed by GC-MS technique and the properties of distinguished compounds showed antifungal, antimicrobial and antibiotic activities. Volatile compounds of T. harzianum and T. viride showed highest percent abundance for glacial acetic acid (45.32%) and propyl-benzene (41.75%), respectively. In case of non-volatile compounds, T. harzianum and T. viride showed D-Glucose, 6-O-α-D-galactopyranosyl- (38.45%) and 17-Octadecynoic acid (36.23%), respectively. The results of present study confirmed that T. harzianum can be used as a promising biological control agent against Alternaria and Fusarium spp. that cause diseases in various vegetables and crops. © 2017 Informa UK Limited, trading as Taylor & Francis Group.
Beneficial microbes for disease suppression and plant growth promotion
(Springer Singapore, 2017) Mukesh Meena; Prashant Swapnil; Andleeb Zehra; Mohd Aamir; Manish Kumar Dubey; Jyoti Goutam; R.S. Upadhyay
Plant growth-promoting microorganisms (PGPMs) constitute the microbes that are intricately associated with the plant system and may consist of rhizospheric bacteria, fungi, mycorrhiza, endophytic fungi, actinomycetes, or those having the mutualistic relationship or nonsymbiotic relationship with plants. One of the most remarkable features of these microbes is the adoption of certain ecological niches or may be occupied with multiple niches at a time in the soil ecosystem that makes way for other species to establish the mutual interactions (physical or biochemical) with other microbes (bipartite) or with plants (tripartite). The plant growth promotion by these microbes involves common mechanisms such as nitrogen fixation, siderophore production, phytohormone production, solubilization of mineral phosphates and secretion of novel secondary metabolites having positive effect on plant health. Some beneficial fungi have been found to promote plant growth through increased photosynthetic rate with improved mineral use efficiency and nutrient uptake, as inoculating these microbes with plants lead into increased chlorophyll content and biomass. These indigenous microbes have been also reported to counteract the different abiotic and biotic stress conditions. The mutual interaction observed between beneficial fungi and pathogenic microbes has been investigated at microscopic level which involves certain physical changes such as coiling of beneficial hyphae around the pathogenic hyphae and some cellular changes such as dissolution of host cytoplasm or secretion of antimicrobial compounds or lytic enzymes in the nearby localities that check the growth and reproduction of pathogenic species. The comprehensive knowledge of the functional mechanism of plant growth promotion by these microbes will help to develop strategies against damages covered by various abiotic and biotic stress conditions, and therefore will help in increasing the agricultural production at a global scale. © Springer Nature Singapore Pte Ltd. 2017. All rights are reserved.
Characterization of plant growth promoting rhizobacteria (PGPR) isolated from the rhizosphere of Vigna radiata (mung bean)
(Elsevier Ltd, 2018) Punam Kumari; Mukesh Meena; R.S. Upadhyay
The rhizosphere is the zone under influence of plant roots where various kinds of microbial activities occur which perform important functions such as increase uptake of nutrients for the host for their better growth and protection from several diseases caused by various phytopathogens. Keeping in this vital role performed by rhizospheric microbes, thirty-nine bacterial isolates were isolated on King's B and nutrient agar media from the rhizosphere region of mung bean plants. Among these isolates, foure were identified as Pseudomonas spp., Bacillus sp., Acinetobacter sp. on the basis of biochemical and 16 S rDNA gene sequencing analysis. All the isolates were screened in vitro for plant growth promoting attributes such as IAA production, phosphate solubilization, ammonia production, catalase production, siderophore production, and antagonistic activity against phytopathogenic Rhizoctonia solani, the causal organism of root rot in mung bean. All the bacterial strains showed significant PGPR attributes and were able to produce indole-3 -acetic acid (ranging from 45.66 µg/ml to 111.94 µg/ml). In addition, the isolated strains enhanced phosphate solubilization activity (ranging from 952.91 µg/ml to 1341.24 µg/ml). Out of all, Pseudomonas spp. showed most potent antifungal activities against R. solani. Thus, the current study has focused on the characterization of rhizobacteria isolated from the rhizosphere of healthy mung bean plant. The results showed that the isolates posses, multiple plant growth-promoting (PGP) traits and can be used as a potential candidate on the soil-plant system to increase their growth as well as productivity. © 2018 Elsevier Ltd
Comparative evaluation of biochemical changes in tomato (Lycopersicon esculentum Mill.) infected by alternaria alternata and its toxic metabolites (TeA, AOH, and AME)
(Frontiers Research Foundation, 2016) Mukesh Meena; Andleeb Zehra; Manish K. Dubey; Mohd Aamir; Vijai K. Gupta; Ram S. Upadhyay
In the present study, we have evaluated the comparative biochemical defense response generated against Alternaria alternata and its purified toxins viz. alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TeA). The necrotic lesions developed due to treatment with toxins were almost similar as those produced by the pathogen, indicating the crucial role of these toxins in plant pathogenesis. An oxidative burst reaction characterized by the rapid and transient production of a large amount of reactive oxygen species (ROS) occurs following the pathogen infection/toxin exposure. The maximum concentration of hydrogen peroxide (H2O2) produced was reported in the pathogen infected samples (22.2-fold) at 24 h post inoculation followed by TeA (18.2-fold), AOH (15.9-fold), and AME (14.1-fold) in treated tissues. 3,3′- Diaminobenzidine staining predicted the possible sites of H2O2 accumulation while the extent of cell death was measured by Evans blue dye. The extent of lipid peroxidation and malondialdehyde (MDA) content was higher (15.8-fold) at 48 h in the sample of inoculated leaves of the pathogen when compared to control. The cellular damages were observed as increased MDA content and reduced chlorophyll. The activities of antioxidative defense enzymes increased in both the pathogen infected as well as toxin treated samples. Superoxide dismutase (SOD) activity was 5.9-fold higher at 24 h post inoculation in leaves followed by TeA (5.0-fold), AOH (4.1-fold) and AME (2.3-fold) treated leaves than control. Catalase (CAT) activity was found to be increased upto 48 h post inoculation and maximum in the pathogen challenged samples followed by other toxins. The native PAGE results showed the variations in the intensities of isozyme (SOD and CAT) bands in the pathogen infected and toxin treated samples. Ascorbate peroxidase (APx) and glutathione reductase (GR) activities followed the similar trend to scavenge the excess H2O2. The reduction in CAT activities after 48 h post inoculation demonstrate that the biochemical defense programming shown by the host against the pathogen is not well efficient resulting in the compatible host−pathogen interaction. The elicitor (toxins) induced biochemical changes depends on the potential toxic effects (extent of ROS accumulation, amount of H2O2 produced). Thus, a fine tuning occurs for the defense related antioxidative enzymes against detoxification of key ROS molecules and effectively regulated in tomato plant against the pathogen infected/toxin treated oxidative stress. The study well demonstrates the acute pathological effects of A. alternata in tomato over its phytotoxic metabolites. © 2016 Meena, Zehra, Dubey, Aamir, Gupta and Upadhyay.
Comprehensive journey from past to present to future about seed priming with hydrogen peroxide and hydrogen sulfide concerning drought, temperature, UV and ozone stresses- a review
(Springer Science and Business Media Deutschland GmbH, 2024) Rashmi Choudhary; Vishnu Dayal Rajput; Gajanan Ghodake; Faheem Ahmad; Mukesh Meena; Reiaz ul Rehman; Ram Prasad; Rajesh Kumar Sharma; Rachana Singh; Chandra Shekhar Seth
Background and aims: Abiotic stresses lead to drastic changes in functional and physiological anatomy in plants such as generation of reactive oxygen species, loss of photosynthetic efficiency, membrane damage etc resulting in a slower expansion and causing a significant harvest penalty. Methodologies like conventional breeding or the use of transgenics are in trend to abate stress impacts on plants, however, alternatively, the use of simple and cost-effective solutions to this problem are also popular. This review focuses on the amelioration of four chief abiotic stressors in plants with reference to priming by H2O2 and H2S. In light of this, the mechanism of resilience to abiotic stress is thoroughly elucidated from past to current scientific efforts in addition to elaborating the critical knowledge gaps and bridging those as well. There are reviews on the use of these two molecules in agronomic systems for drought, and, heat stresses, however, the present review differs in reviewing their impacts on very less addressed UV and ozone stress, including their parallel view of action in terms of similarities and dissimilarities elaborating the interconnection with other signaling molecules. Conclusion: Recently, pre-treatment with hydrogen peroxide (H2O2) and hydrogen sulfide (H2S) has emerged as an economic, feasible, and efficient approach to abate the various abiotic stresses. H2O2 and H2S are multitasking cell signaling molecules in plants. Chemical priming with H2O2 and H2S helps in acclimation of seedlings by hardening and activating antioxidant machinery and thus, in stress tolerance to deal with numerous abiotic stress exposures like drought, temperature, UV, and ozone stress. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024.
Effect on lycopene, β-carotene, ascorbic acid and phenolic content in tomato fruits infected by Alternaria alternata and its toxins (TeA, AOH and AME)
(Taylor and Francis Ltd., 2017) Mukesh Meena; Andleeb Zehra; Prashant Swapnil; Manish Kumar Dubey; Chandra Bali Patel; R.S. Upadhyay
Tomato is considered as one of the most important sources of nutrients such as lycopene, β-carotene, flavonoids, ascorbic acid (vitamin C) and hydroxyl-cinnamic acid derivatives. The quality and quantity of nutrients in tomato fruits were decreased during the severe infection of Alternaria alternata. The present study deals with the estimation of lycopene, β-carotene, phenolic and ascorbic acid content in tomato fruits which were infected with A. alternata and its toxins such as tenuazonic acid (TeA), alternariol (AOH) and alternariol monomethyl ether (AME). The lycopene, β-carotene, ascorbic acid and phenolic content were found lowest in pathogen-infected fruits i.e. (0.66 ± 0.03 mg/g), (0.14 ± 0.01 mg/g), (1.89 ± 0.2 mg/g) and (0.58 ± 0.05 mg/g), respectively, followed by toxins-treated samples as compared to the control. The results concluded that A. alternata mostly affects the nutritional values of tomato fruits due to the combined effect of the toxins. © 2017 Informa UK Limited, trading as Taylor & Francis Group.
Efficiency of microbial bio-agents as elicitors in plant defense mechanism under biotic stress: A review
(Elsevier Ltd, 2021) Andleeb Zehra; Namita Anant Raytekar; Mukesh Meena; Prashant Swapnil
Numerous harmful microorganisms and insect pests have the ability to cause plant infections or damage, which is mostly controlled by toxic chemical agents. These chemical compounds and their derivatives exhibit hazardous effects on habitats and human life too. Hence, there's a need to develop novel, more effective and safe bio-control agents. A variety of microbes such as viruses, bacteria, and fungi possess a great potential to fight against phytopathogens and thus can be used as bio-control agents instead of harmful chemical compounds. These naturally occurring microorganisms are applied to the plants in order to control phytopathogens. Moreover, practicing them appropriately for agriculture management can be a way towards a sustainable approach. The MBCAs follow various modes of action and act as elicitors where they induce a signal to activate plant defense mechanisms against a variety of pathogens. MBCAs control phytopathogens and help in disease suppression through the production of enzymes, antimicrobial compounds, antagonist activity involving hyper-parasitism, induced resistance, competitive inhibition, etc. Efficient recognition of pathogens and prompt defensive response are key factors of induced resistance in plants. This resistance phenomenon is pertaining to a complex cascade that involves an increased amount of defensive proteins, salicylic acid (SA), or induction of signaling pathways dependent on plant hormones. Although, there's a dearth of information about the exact mechanism of plant-induced resistance, the studies conducted at the physiological, biochemical and genetic levels. These studies tried to explain a series of plant defensive responses triggered by bio-control agents that may enhance the defensive capacity of plants. Several natural and recombinant microorganisms are commercially available as bio-control agents that mainly include strains of Bacillus, Pseudomonads and Trichoderma. However, the complete understanding of microbial bio-control agents and their interactions at cellular and molecular levels will facilitate the screening of effective and eco-friendly bio-agents, thereby increasing the scope of MBCAs. This article is a comprehensive review that highlights the importance of microbial agents as elicitors in the activation and regulation of plant defense mechanisms in response to a variety of pathogens. © 2021 The Author(s)
Endophytic Nanotechnology: An Approach to Study Scope and Potential Applications
(Frontiers Media S.A., 2021) Mukesh Meena; Andleeb Zehra; Prashant Swapnil; Harish; Avinash Marwal; Garima Yadav; Priyankaraj Sonigra
Nanotechnology has become a very advanced and popular form of technology with huge potentials. Nanotechnology has been very well explored in the fields of electronics, automobiles, construction, medicine, and cosmetics, but the exploration of nanotecnology’s use in agriculture is still limited. Due to climate change, each year around 40% of crops face abiotic and biotic stress; with the global demand for food increasing, nanotechnology is seen as the best method to mitigate challenges in disease management in crops by reducing the use of chemical inputs such as herbicides, pesticides, and fungicides. The use of these toxic chemicals is potentially harmful to humans and the environment. Therefore, using NPs as fungicides/ bactericides or as nanofertilizers, due to their small size and high surface area with high reactivity, reduces the problems in plant disease management. There are several methods that have been used to synthesize NPs, such as physical and chemical methods. Specially, we need ecofriendly and nontoxic methods for the synthesis of NPs. Some biological organisms like plants, algae, yeast, bacteria, actinomycetes, and fungi have emerged as superlative candidates for the biological synthesis of NPs (also considered as green synthesis). Among these biological methods, endophytic microorganisms have been widely used to synthesize NPs with low metallic ions, which opens a new possibility on the edge of biological nanotechnology. In this review, we will have discussed the different methods of synthesis of NPs, such as top-down, bottom-up, and green synthesis (specially including endophytic microorganisms) methods, their mechanisms, different forms of NPs, such as magnesium oxide nanoparticles (MgO-NPs), copper nanoparticles (Cu-NPs), chitosan nanoparticles (CS-NPs), β-d-glucan nanoparticles (GNPs), and engineered nanoparticles (quantum dots, metalloids, nonmetals, carbon nanomaterials, dendrimers, and liposomes), and their molecular approaches in various aspects. At the molecular level, nanoparticles, such as mesoporous silica nanoparticles (MSN) and RNA-interference molecules, can also be used as molecular tools to carry genetic material during genetic engineering of plants. In plant disease management, NPs can be used as biosensors to diagnose the disease. © Copyright © 2021 Meena, Zehra, Swapnil, Harish, Marwal, Yadav and Sonigra.
Endophytic fungi: Carrier of potential antioxidants
(Springer Singapore, 2018) Jyoti Goutam; Ranjana Singh; Rajyoganandh S. Vijayaraman; Mukesh Meena
The asymptomatic association of fungi with plants is termed as endophytes. These plant-associated mycoflora are a promising source of bioactive natural products. Metabolites released by endophytes not only possess many important functions but also supply antioxidant compounds, which are expected to fight disease due to its anti-aging properties. Currently, hectic lifestyle and stressful environment have become the prime cause for the generation of excessive free radicals in the human body. These free radicals create a destructive process in the body cells which leads to various chronic diseases and deleterious effects. Antioxidants are the chemical moieties that engulf free radicals which are followed by delaying cell damages and health disorders. Antioxidant moieties are generally synthesized by both plants and other microorganisms to survive adverse situations such as harmful radiations and abiotic and biotic stress. Hence, they are beneficial to both plants and animals which fed on the plant, thereby decreasing the reactive oxygen species level which are elevated in their normal metabolism process. Collectively, they help us to properly detoxify the body from these harmful molecules. This overview will discuss about antioxidants and highlight the different antioxidant compounds that have been derived from endophytic fungi. Although synthetic antioxidant compounds are being used, but due to their side effects and less bioavailability, they are not widely accepted. Therefore endophytes could prove to be a natural resource for sustainable antioxidant. © Springer Nature Singapore Pte Ltd. 2018.
Enhanced protection of tomato against Fusarium wilt through biopriming with Trichoderma harzianum
(Elsevier B.V., 2023) Andleeb Zehra; Mohd Aamir; Manish K. Dubey; Waquar Akhtar Ansari; Mukesh Meena; Prashant Swapnil; R.S. Upadhyay; Mohammad Ajmal Ali; Abdullah Ahmed Al-Ghamdi; Joongku Lee
Objective: Microbial priming represents an adaptive strategy to enhance the plant defense against subsequent challenges incited by pathogenic microbes. The aim of the study was to investigate the effect of priming with Trichoderma harzianum (Th) on the induced resistance potential of tomato after challenged with Fusarium oxysporum f. sp. lycopersici (Fol) pathogen. Methods: This work demonstrated antioxidative and defense related enzyme activities and qRT-PCR to study the resistance mechanisms of tomato plants bioprimed with T. harzianum against Fol pathogen. Result: Microbial biopriming with T. harzianum resulted into enhanced expression of tomato defense-related genes and was accompanied by increased antioxidative enzymic activities. The study reported that the T. harzianum primed plants showed 2.71-fold higher SOD than control and 1.34-fold (Fol + Th) higher SOD activity compared to Fol challenged plants. In contrast, Fol + Th treated showed 5.87-fold and 1.34-fold higher CAT enzyme activity as compared to control and pathogen exposed plants. T. harzianum bioprimed plants noted 1.47- and 11.47-fold enhanced PPO activity as compared to Fol challenged and controls, respectively. PAL and PO activities were also found higher in T. harzianum primed plants. The qRT-PCR revealed that expression of defense related gene showed higher up-regulation in T. harzianum primed plants as compared to pathogen challenged plants. As compared to control, Fol + Th treated plants also showed higher up-regulation of all the studied genes. Conclusion: The study concluded T. harzianum priming aggravates the plant defense system against the Fol challenged condition and accompanied by higher expression of defense related genes and increased antioxidative activities against subsequent Fol attack. © 2022 The Authors
Evaluation of biochemical changes in leaves of tomato infected with Alternaria Alternata and its metabolites
(Society for Plant Research, 2017) Mukesh Meena; V. Prasad; R.S. Upadhyay
The present study was carried out to evaluate the biochemical changes occurring in tomato leaves following treatment with leaf spot disease causing pathogen Alternaria alternata and two of its phytotoxic metabolites. Results revealed that the pathogen treatment caused severe foliar necrosis and by 10th day of treatment almost 3/4th of the leaf area was necrotized. A significant decline in the chlorophyll content was observed in the leaves treated with the pathogen and its metabolites. Reducing sugars showed a visible decline in the treated leaves in comparison to the control leaves. When compared with the control an increase in total soluble protein was observed in leaves treated with the pathogen and its metabolites. In case of phenol, a significant enhancement in phenol content of the pathogen and metabolite treated leaves was observed than the amount detected in control leaves. The results indicate that infection of tomato by the leaf spot pathogen Alternaria alternata and its metabolites causes severe alterations in the amount of various biochemical components. © 2017, SciTechnol, All Rights Reserved.
Evaluation of morpho-physiological growth parameters of tomato in response to Cd induced toxicity and characterization of metal sensitive NRAMP3 transporter protein
(Elsevier B.V., 2018) Mukesh Meena; Mohd Aamir; Vikas Kumar; Prashant Swapnil; R.S. Upadhyay
Cadmium (Cd) is a non essential and toxic heavy metal that gets incorporated in the soil ecosystem through several anthropogenic activities. The Cd contaminated soils might have devastating affects on seed germination, plant growth and development. In the present work, a comparative evaluation was made to determine and optimize the detrimental level of accumulated toxic Cd metal in the tomato (Solanum lycopersicum; CO-3 variety). The perturbed morpho-physiological, biochemical alterations and molecular responses following the Cd induced stress were found to maximum at 250 μM Cd with having the highest expression of LeNRAMP3 gene. The oxidative burst induced and cell death was visualized through histochemical analysis using Evans blue (cell death) and DAB staining (H2O2 accumulation). The structural modelling of metal transporter protein done through homology modelling was found to acquire typical helical configuration, and revealed the potential active site residues involved in metal chelation. The function of LeNRAMP3 was deduced based on the functional annotation of protein AtNRAMP3. The functional signaling network and evolutionary relationships for LeNRAMP3 were explored and predicted based on comparative genomics and proteomic studies using the interactome pathways available for AtNRAMP3. The study revealed that LeNRAMP3 metal transporters are activily involved in Cd translocation from root to leaves of tomato and sensitive at 250 μM Cd concentration in the tomato plants. © 2018 Elsevier B.V.
Functional characterization of microbes and their association with unwanted substance for wastewater treatment processes
(Elsevier Ltd, 2023) Prashant Swapnil; Laishram Amarjit Singh; Chandan Mandal; Abhishek Sahoo; Farida Batool; Anuradha; Mukesh Meena; Pritee Kumari; Harish; Andleeb Zehra
Nowadays, microorganisms can be used to eliminate a variety of pollutants such as toxic metal ions from wastewater. These emergences of harmful elements in wastewater, high-priced cultivation of microbes and technical hitches in industrial scale production appeared as main challenges for thriving coupling of microbes with wastewater. These microbes serve as potential sorbents by following suitable adsorption mechanisms. There are some photobioreactors have been also mentioned in this review which is based on microbial biofilm and emerged as an alternative technology to predictable photosynthetic systems for treatment of wastewater based on biomass production at low cost. Bioremediation using different microbes showed contrast results to remove heavy metals from wastewater. Microorganism such as Nostoc sp., Aspergillus versicolor, Aspergillus lentulus and Aspergillus niger remediate 99.6, 99.89, 99.7 and 98 % of Pb, Cr, Cu and Ni, respectively. In this review, mechanistic approaches and distinct pathways of the microbes for removal of various inorganic and organic compounds from wastewater have been methodically discussed. We have also discussed some major commercial production challenges such as techno-economic feasibility genetic engineering research and biorefinery approach. Overall the review discussed the microbial biodiversity in wastewater and their role in remediation of wastewater and their ability to be a potent candidate headed for sustainable industrial wastewater treatment applications through different approaches such as phytoremediation and bioremediation. This article provides valuable insights into multiple aspects of environmental biotechnology, including photobioreactors, metal uptake capacity of microorganisms, heavy metal contamination and its effects and bioremediation using molecular approaches and wastewater treatment through phytoremediation. Moreover, it contributes to our understanding of these topics and can help in the development of sustainable solutions for environmental remediation and pollution control in wastewater though microorganisms. © 2023 Elsevier Ltd
Fungal biomolecules and their implications
(wiley, 2015) Andleeb Zehra; Manish Kumar Dubey; Arti Tiwari; Mukesh Meena; Punam Kumari; Vivek Kumar Singh; Vijai Kumar Gupta; R.S. Upadhyay
Fungal pathogenesis requires molecular communication between the fungus and its host. Fungus-plant interactions involve complex developmental processes in which a variety of fungal and plant biomolecules are required to determine whether the outcome is a susceptible reaction (successful fungal colonisation of plant tissue) or a resistant reaction (plant mounting a defence that aborts fungal invasion). To understand the molecular basis of fungal diseases, it is necessary to identify the fungal biomolecules that are essential for pathogenic processes and to distinguish them from molecules that may be present during infection but not critical to its outcome. Some fungal biomolecules are clearly involved in the adhesion and penetration, that is, glycerol, hydrophobin, mucilage, and so on, whereas others are required for colonisation of plant tissue after penetration, that is, toxin that induce susceptibility and resistance and enzymes that inactivate plant defence mechanisms. Recent studies have shown the development of semiconductor nanoparticles, biofilms and biosensors from different fungi such as Fusarium oxysporum and Verticillium spp. © 2015 John Wiley & Sons, Ltd. All rights reserved.
Fungal toxins and their impact on living systems
(Springer India, 2014) Vivek Kumar Singh; Mukesh Meena; Andleeb Zehra; Arti Tiwari; Manish Kumar Dubey; R.S. Upadhyay
Some of the most potent toxins are synthesized by fungi. Fungal toxins are the chemicals produced by fungi under certain conditions. They may be classified under different chemical classes. They are not essential for fungal growth or reproduction, but are toxic to plants, animals or humans. Fungal toxin contamination in certain agricultural commodities has been a serious concern for animal and human health. The major toxin-producing fungi are the species of Aspergillus, Penicillium, Fusarium and Alternaria. Aflatoxins, citrinin, fumonisins, fusaric acid, moniliformin, AALtoxins and alternariol are some of the important fungal toxins responsible for causing economic losses to agriculture, spoilage of food that are often fatal to living systems. This review focuses on toxigenic fungi, toxins and their characteristics with biological effects. © Springer India 2014 This work is subject. All rights reserved.