Browsing by Author "Sandhya Yadav"

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Acute cadmium toxicity and post-stress recovery: Insights into coordinated and integrated response/recovery strategies of Anabaena sp. PCC 7120
(Elsevier B.V., 2021) Akanksha Srivastava; Subhankar Biswas; Sandhya Yadav; Sanjiv Kumar; Vaibhav Srivastava; Yogesh Mishra
Cyanobacteria, the first photoautotrophs have remarkable adaptive capabilities against most abiotic stresses, including Cd. A model cyanobacterium, Anabaena sp. PCC 7120 has been commonly used to understand cyanobacterial plasticity under different environmental stresses. However, very few studies have focused on the acute Cd toxicity. In this context, Anabaena was subjected to 100 μM Cd for 48 h (acute Cd stress, ACdS) and then transferred into the fresh medium for post-stress recovery (PSR). We further investigated the dynamics of morpho-ultrastructure, physiology, cytosolic proteome, thylakoidal complexes, chelators, and transporters after ACdS, as well as during early (ER), mid (MR), and late (LR) phases of PSR. The findings revealed that ACdS induced intracellular Cd accumulation and ROS production, altered morpho-ultrastructure, reduced photosynthetic pigments, and affected the structural organization of PSII, which subsequently hindered photosynthetic efficiency. Anabaena responded to ACdS and recovered during PSR by reprogramming the expression pattern of proteins/genes involved in cellular defense and repair; CO2 access, Calvin-Benson cycle, glycolysis, and pentose phosphate pathway; protein biosynthesis, folding, and degradation; regulatory functions; PSI-based cyclic electron flow; Cd chelation; and efflux. These modulations occurred in an integrated and coordinated manner that facilitated Anabaena to detoxify Cd and repair ACdS-induced cellular damage. © 2021 Elsevier B.V.
Bryophytes as Modern Model Plants: An Overview of Their Development, Contributions, and Future Prospects
(Springer, 2023) Sandhya Yadav; Suvajit Basu; Akanksha Srivastava; Subhankar Biswas; Raju Mondal; Vishal Kumar Jha; Sushil Kumar Singh; Yogesh Mishra
Model organisms are commonly employed in research as convenient tools for studying diverse biological processes. Plant research relied on several non-model plants until the Arabidopsis thaliana was developed as powerful model for identifying genes and determining their functions. To study the genetics of unique processes in different species, few other model photosynthetic organisms have recently been established, including Synechocystis sp. PCC 6803, Anabaena sp. PCC 7120, Chlamydomonas reinhardatii, Oryza sativa, Zea mays, Triticum dicoccoides, Populus trichocarpa, and Picea abies. However, when it comes to answering different biological problems, each of the current model plants has its own set of advantages and disadvantages, and many questions about land plant adaptation strategies at the level of morpho-physiology, development, and stress mitigation could not be adequately answered using these models. Furthermore, the high occurrence of embryo lethal mutations rendered studying the molecular basis of 3-dimensional (3-D) growth and gametogenesis unfeasible. Since bryophytes have a low cellular complexity and a dominant haploid gametophytic phase, they could be useful models not only for avoiding the aforementioned drawbacks, but also for functional genomics research and understanding the chronology of land plant evolution. These distinguishing characteristics and the advancement of sequencing technology have led to the development of some bryophytes as modern model plants, including Physcomitrium patens, Marchantia polymorpha, Anthoceros agrestis. Here, we review at how bryophytes became model plants, and how they have been able to answer crucial plant biology-related concerns like stress tolerance and evolutionary developmental (evo-devo) biology that other model plants have not been able to. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
Comparison and optimization of protein extraction and two-dimensional gel electrophoresis protocols for liverworts
(BioMed Central Ltd., 2020) Sandhya Yadav; Akanksha Srivastava; Subhankar Biswas; Neha Chaurasia; Sushil Kumar Singh; Sanjiv Kumar; Vaibhav Srivastava; Yogesh Mishra
Objective: Liverworts possess historical adaptive strategies for abiotic stresses because they were the first plants that shifted from water to land. Proteomics is a state-of-the-art technique that can capture snapshots of events occurring at the protein level in many organisms. Herein, we highlight the comparison and optimization of an effective protein extraction and precipitation protocol for two-dimensional gel electrophoresis (2-DE) of liverworts. Results: We compared three different protein extraction methods, i.e.,1.5 M Tris-HCl (pH 8.8), 50 mM Tris-HCl (pH 7.5), and polyvinylpolypyrrolidone (PVPP) extraction, followed by three precipitation methods, i.e., 80% ethanol, 80% acetone, and 20% tricholoroacetic acid (TCA)-acetone, in a liverwort Dumortiera hirsuta. Among these methods, 50 mM Tris-HCl (pH 7.5) extraction, followed by 20% TCA-acetone precipitation, appeared to be more suitable for 2-DE. Furthermore, we performed modifications during protein washing, re-solubilization in rehydration buffer and isoelectric focusing (IEF). The modifications provided us better results in terms of protein yield, resolution, spot numbers, and intensities for 2-DE gels of D. hirsuta and other two liverworts, i.e., Marchantia paleacea and Plagiochasma appendiculatum. Furthermore, we randomly selected spots from the 2-DE gel of D. hirsuta and identified using mass spectrometry, which confirms the applicability of this protocol for liverworts proteomics. © 2020 The Author(s).
Development of Bryophytes as a New Model System to Understand the Phenomenon of Terrestrialization with Environmental Changes
(Springer Nature, 2019) Sandhya Yadav; Subhankar Biswas; Akanksha Srivastava; Yogesh Mishra
Bryophytes are earliest diverging lineages of the extant land plants with around 25,000 species distributed all over the world. Bryophytes can be further classified into three main classes viz. Liverworts, Hornworts and Mosses that grow on a wide range of habitats. Bryophytes, with high ecological and economic values, occupy a very important position in the evolution of terrestrial plants. During the transition of aquatic to terrestrial habitat (terrestrialization), bryophytes got exposed to global climate changes as well as dehydrating atmosphere of terrestrial habitats that led to the desiccation of plant tissues. In order to tolerate the environmental alterations and to protect themselves from abiotic stresses, bryophytes must have enabled themselves to develop certain adaptive strategies. In order to understand these adaptive strategies at molecular level, attempts have been made to develop certain bryophytes as new model system such as Physcomitrella patens and Marchantia polymorpha. In the current chapter we will addresses how does these model systems have been used to address the uniqueness of bryophytes in terms of their capabilities behind the conquering the land i.e. terrestrialization. © 2019, Springer Nature Singapore Pte Ltd.
Evolution of Genetically Modified (GM) Crops and The Scared World
(Elsevier, 2020) Subhankar Biswas; Akanksha Srivastava; Sandhya Yadav; Yogesh Mishra
Since antiquity, it was a key desire of human beings to develop new crops with higher nutritional values and good flavors. The classical plant breeding approaches has given many improved varieties of crops to the world but it has its own limitations, such as (1) genetic exchange can be done in the same species (2) while crossing, many traits are transferred along with the trait/s of interest that might have undesirable effects on yield potential. To overcome these limitations there was an emergence of new technology that is genetic engineering which has developed transgenic plants which are popularly known as genetically modified (GM) plants. First genetic engineering mediated transgenic tobacco plant was developed in 1987. After that, there was a boom in the development of GM crops such as “flavr-savr” tomato, Bt-cotton, corn, etc. In the journey of the past 3 decades, GM crops faced several vicissitudes but never stopped its improvement. The case-by-case study has demonstrated that the technique was never the problem but the consequences may be. In this chapter, we have briefly highlighted the necessity, current status and global impact of genetically modified plants. Apart from these, we have also addressed the question that why a large part of the human population is still scared of GM foods?. © 2021 Elsevier Inc. All rights reserved.
Physiological and thylakoid proteome analyses of Anabaena sp. PCC 7120 for monitoring the photosynthetic responses under cadmium stress
(Elsevier B.V., 2021) Akanksha Srivastava; Subhankar Biswas; Sandhya Yadav; Arvind Kumar; Hema Rajaram; Vaibhav Srivastava; Yogesh Mishra
Photosynthetic organisms are highly susceptible to cadmium (Cd) as it interferes with the structural and functional aspects of the photosynthesis. As a major group of photosynthetic prokaryotes, cyanobacteria are also affected by Cd. The inhibitory effects of Cd on cyanobacterial photosynthesis have been studied from an early stage, but the mechanism of Cd toxicity is still unclear. Therefore, we investigated the photosynthetic responses of Anabaena sp. PCC 7120 under Cd stress (LC50) at physiological and thylakoid proteome levels via chlorophyll a fluorescence measurements and blue native (BN)-SDS PAGE, respectively. The findings revealed that Cd exposure triggered the intracellular ROS production and negatively affected the photosynthetic performance. With Cd exposure, effective photochemical quantum yield of PSII (Y(II)) and photochemical quenching efficiency (qP and qL) were significantly reduced, whereas the non-regulated energy dissipation (Y(NO)) was increased. Fast fluorescence kinetic measurements showed that Cd exposure resulted in the inactivation of PSII reaction centres, which interfered with the transfer of energy from antenna complexes to reaction centre, decreased the ability to convert excitation energy into electron transport, increased thermal dissipation, and thus decreased linear electron flow efficiency. Conversely, the efficiency of electron transfer from intermediate carriers to final PSI acceptors was increased, which might be related to the induction of PSI-based cyclic electron flow. This assumption was confirmed by an enhanced post-illumination fluorescence transient. Consistent with these observations, BN-SDS PAGE showed that Cd exposure significantly decreased PSII subunit proteins accumulation, but slightly increased PSI proteins accumulation. Additionally, only minor reductions in the accumulation of ATP synthase/NDH-1 and Cytochrome b6f subunit proteins were observed. The transcript levels of most of the selected subunit proteins were in accordance with BN-SDS PAGE. Collectively, our experiments show that a shift to PSI-based cyclic electron flow was a protective strategy of Anabaena sp. PCC 7120 against Cd-induced PSII photo-damage. © 2021 Elsevier B.V.
Seasonal Changes in the Antioxidative Defence System of a Liverwort Dumortiera hirsuta
(Springer, 2022) Sandhya Yadav; Akanksha Srivastava; Subhankar Biswas; Suvajit Basu; Sushil Kumar Singh; Yogesh Mishra
Liverworts are influenced by several ecological factors, such as photoperiod, temperature, precipitation, and nutrient availability. These factors vary in different seasons of the Indian calendar year, divisible into pre-monsoon (March–May), monsoon (June–August), post-monsoon (September–November), and fruiting (December–February) seasons. Seasonality causes disturbance in cellular homeostasis, which may trigger ROS formation. To restore the threshold level of ROS, liverworts must be equipped with complex antioxidant defence machinery. Thus, in this study, we analysed the effect of seasonal changes on oxidative stress markers [malondialdehyde (MDA) and total peroxide (H2O2 content)], total protein and pigment contents, and enzymatic and non-enzymatic antioxidants activities/contents in a liverwort, Dumortiera hirsuta, during its four distinct growing seasons. During the fruiting season, the results revealed the highest level of MDA and H2O2 with the lowest level during the pre-monsoon/monsoon seasons. The protein and pigment contents were maximal during the monsoon season and minimal during the fruiting season. With the exception of few [ascorbate peroxidase (APX) and ascorbic acid (ASC)], enzymatic [superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR)] and non-enzymatic antioxidants (total thiol, proline, and carotenoids) activities/contents were correspondingly high during the fruiting season and low during the pre-monsoon/monsoon seasons, indicating their defensive role in neutralizing/suppressing the increased ROS during the fruiting season when the temperature was very low and the nutrient availability was less. These results therefore suggest that the antioxidative defence machinery plays a potential role in the adaptation of D. hirsuta against oxidative stress, naturally imposed by seasonal climatic changes. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
Two Evolutionary Diverged Liverworts that Shared the Same Habitats Developed a Few Distinct Seasonal Adaptive Strategies: Insights from a Transcriptomic Approach
(Springer, 2025) Suvajit Basu; Sandhya Yadav; Vishal Kumar Jha; Subhankar Biswas; Akanksha Srivastava; Kritika Tripathi; Raju Mondal; Neha Chaurasia; Sushil Kumar Singh; Yogesh Mishra
Since liverworts are among the earliest land plants to undergo seasonal fluctuations, they hold the secret to the molecular mechanism behind seasonal adaptation. Depending on their evolutionary histories, different liverwort species may have relatively distinct adaptive mechanisms. We therefore, performed a seasonal transcriptome analysis of two Indian liverworts, Dumortiera hirsuta and Plagiochasma appendiculatum, during their four different growing seasons (pre-monsoon, monsoon, post-monsoon, and fruiting season). These two species diverged at different points in their evolutionary history but coexist in the same habitat. Phylogenetic trees and evolutionary timescale analyses showed that D. hirsuta is primitive than P. appendiculatum. The RNA-seq analysis showed that D. hirsuta primarily modifies its transcriptome by differentially regulating growth, metabolism, and stress-responsive genes and related TFs in the post-monsoon but mainly induces specific stress-responsive genes in the fruiting season. This is likely to develop reproductive organs in the post-monsoon season and to strategically adapt to the harsh environmental conditions of both seasons by conserving energy during the fruiting season. Conversely, P. appendiculatum exhibited significant transcriptome variability by modulating the expression of genes with similar functions during both the fruiting and post-monsoon seasons, albeit to a lesser degree than D. hirsuta. This suggests that P. appendiculatum strategically modulated its necessary gene expression levels over an extended period of time while taking energy conservation into consideration in order to survive the harsh conditions of both seasons. This study offers the first comprehensive view of seasonal adaptive strategies employed by two evolutionary diverged liverworts that coexist in the same habitat. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.