Browsing by Author "Madhulika Singh"

Now showing 1 - 17 of 17

Alkaline phosphatase as a bio-indicator of phosphorus-eutrophy in freshwater ecosystems: A review
(Elsevier B.V., 2023) Madhulika Singh; Jitendra Pandey
Limnologists have greatly advanced the understanding of indicators of phosphorus (P)-eutrophy in surface waters. Biotic variables such as macro-invertebrates, fish, zooplankton, benthic algae, and diatoms are extensively used for bio-assessment of eutrophy. New concepts highlight the importance of bed-sediment based “response” variables predicting functional shifts during eutrophication. A cross analysis of studies reveals that alkaline phosphatase (ALP), which serves as a proxy of P-deficiency, and also as an indicator of benthic anoxia/hypoxia-driven feedbacks, can be an easy to measure, cost-effective and reliable tool to assess changes in nutrient stoichiometry, trophic status, and ecological functioning at the sediment–water interface. Here, the issues discussed in this paper are highly relevant to explore new domains of research and “response” based ecosystem models for potential eutrophication management decisions. Because ALP is used in molecular cloning and fingerprinting studies, it is suggested that approaches based on the “omics” technologies need to be used to explore more intricate connections to empirically address ALP-P-eutrophy linkages to track eutrophication in freshwater ecosystems. © 2023
An introduction of parthenium hysterophorus to be boon for agricultural land: Under heavy metal contamination
(Plant Archives, 2020) Madhulika Singh; Pratibha Singh; Rajiv Kumar Singh; Pankaj Kumar Singh; Sheo Mohan Prasad; Aparna Pandey
Recently, the contamination of agricultural land possesses major threats to human health and the environment. The catastrophic events comprising geologic activities and anthropogenic activities leave every year a huge amount of nutrient/metal ions in agricultural land/water bodies, they remain in soil for many years and are the potential cause of phytotoxicity or poisoning of the food chain. Generally metal ions are essential in trace amount for the normal development of animals and plants but become toxic when accumulated at higher concentrations. Among the number of practices, phytoremediation was initially proposed as an environmental cleanup technology for the remediation of metal contaminated land. © 2020 Plant Archives. All rights reserved.
Application of soil amendments mitigates phytotoxic effects on Solanum melongena L. and Lycopersicon esculentum L. seedlings exposed to chlorpyrifos and dimethoate pesticides
(Springer Science and Business Media Deutschland GmbH, 2023) Pratibha Singh; Madhulika Singh; Sunita Kumari Singh; Sheo Mohan Prasad
This field study was done to study the effects of pesticides chlorpyrifos and dimethoate singly and in combination with soil amendments like chemical fertilizer (CF), farmyard manure (FM), and 50% CF + 50% FM (CM) on various indices of growth, physio-biochemical parameters of brinjal, and their residual effect in tomato seedlings. As compared to the control, the decrease of 9.5 and 5.5%, 8.9 and 5.0% in fresh weight, dry weight respectively was recorded in the pesticide-only treatment in the brinjal crop. Pesticides when applied in combination with soil amendments depicted the highest growth of 105.4 and 118.2%, 104.1 and 115.1% in pesticides + CF treatment, 72.7 and 85.1%, 68.1 and 78.1% in pesticides + CM treatment, and 64.4 and 74.0%, 62.7 and 65.7% in pesticides + FM treatment compared to control. In tomato seedlings, the pesticides + CF treatment exhibited the lowest growth indices (25.5 and 31.9%, 26.4 and 28.8%) across the combined treatments while pesticide-only treatment depicted minimum growth compared to the control. In the case of photosynthesis rate and antioxidant activity, the combined treatments showed the trend as pesticides + CF > pesticides + CM > pesticides + FM in the brinjal crop; however, the trend became somewhat reversed in the tomato crop. The results indicated that soil-amended practices modulated pesticide-induced damage by upregulating photosynthetic performance, chlorophyll a fluorescence, and antioxidant balancing which might be associated with the mitigation of ROS-induced pesticide toxicity, and the effect was more pronounced with CM. Furthermore, our study was supported by non-metric-multidimensional scaling (NMDS)-constructed ordination plots by showing spatial patterns in different variables. The study might help in taking management decision to design mitigation actions for government and non-government agency at the farmers’ level. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Cereals and Phytohormones Under Salt Stress
(Springer Nature, 2022) Varunendra Kumar Singh; Sakshi Pandey; Nidhi Verma; Madhulika Singh; Jitendra Pandey; Sheo Mohan Prasad
Cereal crops are occupying a dynamic part in nourishing the whole population of the world. The development and production of these cereal crops are poorly affected when exposed to different environmental abiotic stresses, among which salinity stress plays a major role. Plants that respond to salt stress involve various complex physiological, molecular, as well as biochemical changes in the plant system. Phytohormones play a crucial role in acquiring some adaptational reactions in a plant's system when exposed to salinity. Gibberellins (GAs), ethylene (ET), cytokinins (CKs), salicylic acid (SA), jasmonates, abscisic acid (ABA), and brassinosteroids (BRs) are important plant hormones that respond to salinity stresses via their signalling attributes. The cellular disturbances caused by salinity stress are potentially removed by exogenous phytohormones in plants. Phytohormones extensively regulate some specific genes to deal with saline conditions. In this chapter, the collective information is mentioned which is focused on the role of phytohormones along with the involved genes in the alleviation of salinity stress in cereal crops. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022
COVID-19 lockdown–driven changes in the Ganga River ecosystem in response to human perturbations
(Springer Science and Business Media Deutschland GmbH, 2022) Madhulika Singh; Jitendra Pandey
We examined 10 subsurface water, 5 benthic water and 19 sediment (02 cm) samples along a 518 km of the middle segment of the Ganga River to assess the possible improvements that resulted from the industrial shutdown during the COVID-19 pandemic. The sites included the main stem river, tributary confluences, and two point sources, one of which releases metal-rich effluents and the other flushes municipal sewage. We found significant declines in the carbon, nutrient and metal concentrations in both the water and sediment. Even the most polluted zones did not show hypoxia (dissolve oxygen; DO < 2.0 mg L−1) that had been observed in the previous year. Despite a significant decline in carbon and nitrogen as substrates, the activities of extracellular enzymes (EEs), such as β-D-glucosidase, FDAase and protease in sediment (0–2 cm depth), increased significantly (p < 0.05) in response to the declining metal concentrations resulting from the industrial shutdown. We found strong negative correlations between EE activity and the concentrations of metal pollutants measured in 2019, but the correlations between these variables appeared poor in 2020 (lockdown period). Also, we found large variances (low stability coefficients) during the period of strong anthropogenic effects (2019). The study indicates that industrial sources are important contributors of metal pollution in the Ganga River and has relevance exploring river ecosystem recovery windows for management decisions. © 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG.
Crop Plants Develop Extracellular Signaling Products Against Salt Stress
(wiley, 2021) Santwana Tiwari; Nidhi Verma; Shikha Singh; Shivam Gupta; Madhulika Singh; Pratibha Singh; Jitendra Pandey; Sheo Mohan Prasad
Plant signaling is a usual phenomenon that facilitates the transduction of external and internal signals into physiological reactions such as modification of activity of various enzymes, cytoskeleton structure, and gene expression. This chapter aims to gather all the information about extracellular products secreted by crop plants as well as cyanobacteria with their working mechanisms under salt stress conditions and their role in economic values in agriculture and medicine. The biosynthesis of bioactive extracellular compounds in plants aimed to enhance crop tolerance to abiotic and biotic stresses and overcome stressful conditions. The level of antioxidants, enzymes, and proteins has fluctuated under salt stress. Salt stress often generates both ionic and osmotic stress in plants, resulting in a greater disturbance in signaling and accumulation or decrease of specific metabolites in plants. In agriculture, cyanobacterial and plant's secondary metabolites are key tools for enhancing crop production. © 2022 John Wiley & Sons Ltd. All rights reserved.
Effects of COVID-19 lockdown on water quality, microbial extracellular enzyme activity, and sediment-P release in the Ganga River, India
(Springer Science and Business Media Deutschland GmbH, 2022) Madhulika Singh; Usha Pandey; Jitendra Pandey
This study investigates possible improvement in water quality and ecosystem functions in the Ganga River as influenced by COVID-19 lockdown in India. A total of 132 samples were collected during summer-2020 low flow (coinciding COVID-19 lockdown) for water (sub-surface and sediment-water interface) and 132 samples separately for sediment (river bottom and land-water interface) considering 518-km main river stem including three-point sources (one releases urban sewage and the other two add metal-rich industrial effluents) and a pollution-impacted tributary. Parameters such as dissolved oxygen deficit and the concentrations of carbon, nutrients (N and P), and heavy metals were measured in water. Sediment P-release was measured in bottom sediment whereas extracellular enzymes (EE; alkaline phosphatase, FDAase, protease, and β-D-glucosidase) and CO2 emission were measured at land-water interface to evaluate changes in water quality and ecosystem functions. The data comparisons were made with preceding year (2019) measurements. Sediment-P release and the concentrations of carbon, nutrients, and heavy metals declined significantly (p<0.05) in 2020 compared to those recorded in 2019. Unlike the preceding year, we did not observe benthic hypoxia (DO <2.0 mg L−1) in 2020 even at the most polluted site. The EE activities, which declined sharply in the year 2019, showed improvement during the 2020. The stability coefficient and correlative evidences also showed a large improvement in the water quality and functional variables. Positive changes in functional attributes indicated a transient recovery when human perturbations withdrawn. The study suggests that timing the ecosystem recovery windows, as observed here, may help taking management decision to design mitigation actions for rivers to recover from anthropogenic perturbations. © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
In vitro regeneration and improvement in tropical fruit trees: An assessment
(Springer Netherlands, 2005) Madhulika Singh; Uma Jaiswal; V.S. Jaiswal
In vitro regeneration protocol has been developed for many tropical fruit trees by using juvenile as well as mature explants. Regeneration via somatic embryogenesis have been obtained in a number of cases e.g., while in citrus, sugar apple and papaya, etc. induction of androgenic haploids are successful, in guava and feijoa only callus results in anther cultures. Somaclones have helped in the selection of seedless Musa. Synthetic seed technology has aided in raising plantlets from encapsulated embryos of guava, mango, papaya, etc. Gene transfer techniques can further prove to be useful in the improvement of varieties. © 2005 Springer Science + Business Media, Inc. All rights reserved.
In vitro selection of NaCl-tolerant callus lines and regeneration of plantlets in a bamboo (Dendrocalamus strictus Nees.)
(2003) Madhulika Singh; Uma Jaiswal; Vijai Shanker Jaiswal
Sodium chloride-tolerant plantlets of Dendrocalamus strictus were regenerated successfully from NaCl-tolerant embryogenic callus via somatic embryogenesis. The selection of embryogenic callus tolerant to 100 mM NaCl was made by exposing the callus to increasing (0-200 mM) concentrations of NaCl in Murashige and Skoog medium having 3% (w/v) sucrose, 0.8% (w/v) agar, 3.0 mg1-1 (13.6 μM) 2,4-dichlorophenoxyacetic acid (2,4-D), and 0.5mgl-1 (2.3 μM) kinetin (callus initiation medium). The tolerance of the selected embryogenic callus to 100 mM NaCl was stable through three successive transfers on NaCl-free callus initiation medium. The tolerant embryogenic callus had high levels of Na+, sugar, free amino acids, and proline but a slight decline was recorded in K+ level. The stable 100 mM NaCl-tolerant embryogenic callus differentiated somatic embryos on maintenance medium [MS medium + 3% sucrose + 0.8% agar + 2.0 mgl-1 (9.0 μM) 2,4-D + 0.5 mg 1-1 (2.3 μM) kinetin] supplemented with different (0-200 mM) concentrations of NaCl. About 39% of mature somatic embryos tolerant to 100 mM NaCl germinated and converted into plantlets in germination medium [half-strength MS + 2% sucrose + 0.02 mg 1-1 (0.1 μM) α-naphthaleneacetic acid + 0.1 mg 1-1 (0.49 μM) indole-3-butyric acid] containing 100 mM NaCl. Of these plantlets about 31% established well on transplantation into a garden soil and sand (1:1) mixture containing 0.2% (w/w) NaCl.
Physiology of Salt Stress in Plants: Perception, Signalling, Omics and Tolerance Mechanism
(wiley, 2021) Pratibha Singh; Madhulika Singh; Rajiv Kumar Singh; Sheo Mohan Prasad
Discover how soil salinity affects plants and other organisms and the techniques used to remedy the issue: In Physiology of Salt Stress in Plants, an editorial team of internationally renowned researchers delivers an extensive exploration of the problem of soil salinity in modern agricultural practices. It also discusses the social and environmental issues caused by salt stress. The book covers the impact of salt on soil microorganisms, crops, and other plants, and presents that information alongside examinations of salt’s effects on other organisms, including aquatic fauna, terrestrial animals, and human beings. Physiology of Salt Stress in Plants describes the morphological, anatomical, physiological, and biochemical dimensions of increasing soil salinity. It also discusses potential remedies and encourages further thought and exploration of this issue. Readers are encouraged to consider less hazardous fertilizers and pesticides, to use safer doses, and to explore and work upon salt resistant varieties of plants. Readers will also benefit from the inclusion of: Thorough introductions to salt stress perception and toxicity levels and the effects of salt stress on the physiology of crop plants at a cellular levelExplorations of the effects of salt stress on the biochemistry of crop plants and salt ion transporters in crop plants at a cellular level Practical discussions of salt ion and nutrient interactions in crop plants, including prospective signalling, and the effects of salt stress on the morphology, anatomy, and gene expression of crop plants An examination of salt stress on soil chemistry and the plant-atmosphere continuum Perfect for researchers, academics, and students working and studying in the fields of agriculture, botany, entomology, biotechnology, soil science, and plant physiology, Physiology of Salt Stress in Plants will also earn a place on the bookshelves of agronomists, crop scientists, and plant biochemists. © 2022 John Wiley & Sons Ltd. All rights reserved.
Plant regeneration from alginate encapsulated nodes of Andrographis paniculata (Burm. F.) Wallich ex nees. a potential medicinal herb
(Society for Plant Research, 2018) Madhulika Singh; Chhaya Yadav; Farha Bano
Synthetic seed technology offers tremendous potential for micropropagation, conservation and transport of germplasm of plant species. A ndrographis paniculata (burm. F.) wallich ex nees. is known to possess variety of medicinal value and this study reports germination of encapsulated nodes of A. paniculata under different experimental conditions. The conversion of encapsulated node was affected by sodium alginate concentration and 3% (w/v) sodium alginate was best for encapsulation. Supplementation of medium with low concentration of BAP showed a slight increase in percent germination of encapsulated nodes. Among fructose, glucose, maltose and sucrose the best percent germination was recorded on medium having fructose while shoot growth was favoured in presence of sucrose. One-step conversion of encapsulated node was recorded in half strength growth regulator free Murashige and Skoog (MS) liquid medium. The encapsulated nodes showed capability to retain their viability after storage at 4°C. About 95% synthetic seeds converted into plantlets on half strength MS liquid medium successfully hardened and acclimatized into pots filled with sand and garden soil (3: 1) mixture. © 2018, SPR, All Rights Reserved.
Preface
(wiley, 2021) Pratibha Singh; Madhulika Singh; Rajiv Kumar Singh; Sheo Mohan Prasad
[No abstract available]
Regulation of temperature stress in plants
(Elsevier, 2020) Sanjesh Tiwari; Anuradha Patel; Madhulika Singh; Sheo Mohan Prasad
Plant, during its entire life cycle, from seedling to reproductive stage, faces changing environment that is sometimes unfavorable for growth and developmental processes; plants develop specific mechanism to overcome these environmental stresses. Adverse environmental factors are categorized majorly in two categories: first biotic factors that include pathogen and herbivore attacks, and second, abiotic factors that include drought, heat, cold, nutrient deficiency, and heavy-metal accumulation in the soil. Among these, salt, drought, and temperature affect the geographical distribution of plant species as well as disrupt the plant metabolism. As a consequence, they limit the quality and quantity of food production in agriculture and reducing the food demand for growing population, and to overcome these adverse effects, tolerance mechanism in plants has been well studied. In general, various environmental factors (biotic and abiotic) induce the plant resistance by activation of stress tolerance genes. The average temperature was found to be increased by 0.2°C/year and it has to be increased by 1.8°C-4°C at the end of year 2100, hence temperature is pondered to be one of the utmost detrimental stress. Climate change due to temperature is a global concern that has altered the physiological and biochemical activities of plant, thereby reducing the productivity of crops. Increased temperature continuously caused heat stress in plants, which depends upon the quality, intensity, and duration of light. Generation of reactive oxygen species is a common phenomenon exhibited by all environmental factors (biotic and abiotic), including heat stress that damaged the macromolecules, such as DNA, proteins, and lipids, and plants are under oxidative stress. Furthermore, heat stress also altered the expression of genes that participate in the formation of and responsible for production of osmoprotectants, detoxifying enzymes, transporters, and regulatory proteins. On contrary to this, heat stress inhibits the protein folding, affects the membrane (lipid bilayer) fluidity and cytoskeleton arrangement, and also affects the vegetative and reproductive tissue. Rise in temperature up to a certain limit is beneficial for plant that regulates the circadian rhythms in plants, regulates plant movements (opening/closing of corolla), and also affects the geographical distribution of plants in nature. Plants susceptibility toward pathogen was also enhanced by high temperature. Infection capacity of tobacco mosaic and tomato-spotted wilt viruses were found to be increased when ambient temperature increased and caused viral diseases in tobacco (Nicotiana tabacum) and pepper (Capsicum annuum), respectively. In wheat genotypes, its sensitivity toward Cochliobolus sativus (caused spot blotch) was associated with increase in nighttime temperature. © 2020 Elsevier Inc. All rights reserved.
Role of sRNAs in abiotic stress tolerance
(Elsevier, 2020) Anuradha Patel; Sanjesh Tiwari; Madhulika Singh; Sheo Mohan Prasad
Any external factors either biotic or abiotic that significantly reduced the plants’ ability to convert light energy into biomass are studied under a broad category termed stresses that negatively influence the metabolic activities of plants. Along with biotic and abiotic stresses, overgrowing population also caused a lot of pressure on agricultural fields to fulfill the food demand, but the crops productivity was not increased in such manner as population increased. In natural environment, primary producers, that is, plants face a number of adverse environmental conditions such as high salinity, drought, cold, and heat that limits the biomass production and yield of staple food crops; hence, it is a global concern to fulfill the food demand. Various anthropogenic activities contribute to the abiotic stress that changes the climate of environment that causes threat to food security. These adverse environmental changes hamper the various physiological and metabolic factors that results in death of plants. A physiological alteration under abiotic stresses includes growth inhibition associated with photosynthetic pigment loss, decreased whole-cell oxygen evolution (photosynthesis), and significant increase in oxygen consumption. Plants stimulate various adoptive changes in response to abiotic stresses at physiological, cellular, and molecular level or through genetic regulation or reprogramming the expression of gene. Physiological adaptation includes change in protein modification at transcriptional level as well as at posttranslational level that leads the change in particular phenotype that significantly avoids the stressful conditions. One such approach is through the modification in gene expression and also through the activity of sRNAs, which switches on protective mechanisms, that is, the genes that involve in defense systems are upregulated and gens that involve in toxicity are downregulated. Role of proteomics as stress-tolerance mechanism is well known, whereas the role of sRNA as stress regulators is an emerging molecular tool. Further, due to the development of modern molecular techniques, molecular mechanisms in plants give much more attention to identify the stress-responsive proteins and their regulatory gene networks under posttranslational level. In this line, small noncoding RNAs (sRNAs) are considered posttranscriptional regulatory factor in gene regulation under adverse environmental factors and involved in plant development. In molecular world, RNAs are basically categorized into two into transfer RNA and ribosomal RNA, and the only difference in sRNAs from other forms of RNAs is relatively small size of genome (20-30nt) as well as having capacity to make complex with argonaute (AGO) family proteins considered key components of RISC (RNA-induced silencing complex). Among various types of sRNA, two are major, that is, microRNAs and small interfering RNAs that actively mediate the gene regulation, splicing, DNA methylation, chromatin, protein, and nucleotide modification and sRNA-mediated gene silencing termed RNA interference (RNAi). RNAi significantly inhibits the process of transcription or translation by sequence-specific gene regulation initiated by dsRNA and frequently presents in plants as well as in animals, fungi, and ciliates. The present time is totally dependent on crop improvement techniques under adverse environmental conditions by the use of various molecular approaches and among them RNAi is considered an important tool of genetic engineering and functional genomics. In this chapter, we briefly describe the biogenesis of sRNA and their pivotal role against abiotic stress tolerance. © 2020 Elsevier Inc. All rights reserved.
Salt tolerant callus lines of Dendrocalamus strictus nees under salt stress: Growth and ion accumulation
(Plant Archives, 2019) Madhulika Singh; V.S. Jaiswal; Uma Jaiswal
Plant tissue culture technique offers a suitable opportunity for development of salt tolerant plants. The technique is also helpful in understanding physiological and molecular mechanisms of tolerance to salt stress under In vitro condition at the cellular, organ, and whole-plant level. This study was performed to understand the growth responses and accumulation of Na+ and K+ ions against the salt stress in NaCl tolerant callus of Dendrocalamus strictus Nees. The embryogenic callus tolerant to 100mM NaCl was screened out by exposing to increasing (0-200mM) concentrations of NaCl in 0.8% (w/v) agar gelled Murashige and Skoog medium having 3% (w/v) sucrose, 13.6 µM 2,4-Dichlorophenoxy acetic acid and 2.3µM Kinetin (Callus initiation medium). Stable growth of NaCl tolerant callus lines on NaCl-free as well as on NaCl-containing medium was recorded. The relative growth rate of NaCl sensitive callus decreased significantly with increasing concentrations of NaCl into the medium while, for tolerant callus was consistent on medium having 50 and 100mM NaCl and decreased further with increasing concentration of NaCl. The FW/DW of NaCl sensitive callus was higher than the NaCl- tolerant callus. The ratio K+/Na+ was recorded low when the callus was grown on medium supplemented with NaCl and among sensitive and tolerant callus this ratio was found least in tolerant callus when they were grown on medium having 100mM NaCl. © 2019 Plant Archives. All rights reserved.
Somatic embryogenesis and plant regeneration from suspension cultures of Sapindus trifoliatus
(Springer Science and Business Media B.V., 2024) Madhulika Singh; Pooja Asthana; Manoj K. Rai; Uma Jaiswal
A procedure for plant regeneration from cell suspension cultures through somatic embryogenesis is described for Sapindus trifoliatus, a commercially and medicinally important tree. Callus was induced from leaf disc on agar-solidified MS medium with 5.0 mg l−1 2, 4-D and 0.01 mg l−1 Kin. Embryogenic cell suspension cultures were established by placing leaf-derived friable calli in PGR-free full-strength MS liquid medium with 3% sucrose. The growth of cell suspension culture was significantly affected by the strength of the MS mineral solution and L-glutamine. Plating of the suspension on semisolid MS medium resulted in the formation of globular structures. These embryogenic globular structures differentiated into secondary globular structures or somatic embryos on a semisolid MS medium. The differentiation of globular structures and different stages of somatic embryos (from globular to cotyledonary) was enhanced by the addition of 200 mg l−1 L-glutamine in the medium. Sucrose at relatively high concentrations (5%) or ABA (0.01 mg l−1) promoted somatic embryo maturation. The highest percentage (about 90%) of germination of somatic embryo and plantlet conversion was achieved on a half-strength MS medium containing 2% sucrose. The plants were hardened and established in soil with a 90% survival rate © The Author(s), under exclusive licence to Springer Nature B.V. 2024.
Thidiazuron-induced in vitro flowering in Dendrocalamus strictus Nees
(2000) Madhulika Singh; Uma Jaiswal; V.S. Jaiswal
[No abstract available]