Effect of Land Use Change on Molecular Composition and Concentration of Organic Matter in an Oxisol.

Land use change from native vegetation to cropping can significantly affect the quantity and quality of soil organic matter (SOM). However, it remains unclear how the chemical composition of SOM is affected by such changes. This study employed a sequential chemical extraction to partition SOM from an Oxisol into several distinct fractions: water-soluble fractions (ultrapure water (W)), organometal complexes (sodium pyrophosphate (PP)), short-range ordered (SRO) oxides (hydroxylamine-HCl (HH)), and well-crystalline oxides (dithionite-HCl (DH)). Coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), the impact of land use change on the molecular composition of different OM fractions was investigated. Greater amounts of OM were observed in the PP and HH fractions compared to other fractions, highlighting their importance in SOM stabilization. The composition of different OM fractions varied based on extracted phases, with lignin-like and tannin-like compounds being prevalent in the PP and HH fractions, while aliphatic-like compounds dominated in the DH fraction. Despite changes in the concentration of each OM fraction from native vegetation to cropping, there was little influence of land use change on the molecular composition of OM associated with different mineral phases. No significant selective loss or preservation of organic carbon compounds was observed, indicating the composition of SOM remained unchanged.

Synthesis of bio-stabilized silver nanoparticles using Roccella montagnei, their anticandidal capacities & potential to inhibit the virulence factors in fluconazole-resistant Candida albicans.

Candida species is the causative agent in approximately 80% of invasive mycoses and drug-resistant Candida albicans is among the four strains of 'critical priority group' framed by WHO. Lichens are endowed with some rare phytochemicals and a plethora of therapeutics viz. antifungal capacities of Roccella montagnei. Biosynthesis of silver nanoparticles (AgNPs) using lichen could offer an eco-friendly, and cost-effective alternative against emerging 'microbial resistance.' Therefore, the objective was to biosynthesize silver nanoparticles (Rm-AgNPs) using a Hydro-alcoholic (1:1) extract of R. montagnei to develop a potent anticandidal agent against Fluconazole-resistant C. albicans NBC099. UV-Spectroscopy identified AgNPs specific-peak of Rm-AgNPs at 420-440 nm and FTIR revealed the presence of amines, alcohol, aromatic compounds, and acids. SEM and TEM analysis indicated that Rm-AgNPs are spherical shaped with a size range of 10-50 nm. Zetasizer analysis indicated that particles are highly stable and have a mean hydrodynamic diameter of 116 nm with a zeta potential charge of - 41 mV. XRD analysis suggested face centered cubic crystal lattice structure. Results indicated that Rm-AgNPs strongly inhibited the growth of NBC099 at a minimum inhibitory concentration (IC50) of ≤ 15 µg. C. albicans culture treated with Rm-AgNPs at concentrations below IC50, down-regulates the production of different virulence factors in NBC099, viz. hyphal formation (> 85%), biofilms production (> 80%), phospholipase, esterase, proteinase activity. The apoptosis assay demonstrated the Rm-AgNPs induced apoptosis in NBC099 cells via oxidative stress. Interestingly, Rm-AgNPs showed negligible cytotoxicity (< 6%) in murine RAW 246.7 macrophage cells at a concentration above 15 µg/mL. Therefore, Rm-AgNPs have been offered as an anti-candida alternative that can be utilized to improve the efficacy of already available medications.

Identification of QTLs for zinc deficiency tolerance in a recombinant inbred population of rice (Oryza sativa L.).

BACKGROUND: Deficiency of Zn is a major soil constraint in rice plant growth and yield. Edaphic factors such as Zn deficiency in soil in relation to plant performance are still poorly understood. Here, we report promising quantitative trait loci (QTL) conferring tolerance to Zn deficiency, which were identified through biparental mapping. The experiment was conducted using the 236 F7 recombinant inbred line mapping population derived from the cross of Kinandang Patong (Zn deficiency sensitive) and A69-1 (Zn deficiency tolerant). RESULTS: A total of six QTLs (qLB-2B, qLB-4B, qPM-4B, qPM-6B, qRZC-4B, qSZC-4B) on chromosomes 2, 4 and 6 were identified for environment 1, whereas five QTLs (qLB-2 N, qLB-4 N, qPM-4 N, qRZC-4 N, qSZC-4 N) on chromosomes 2 and 4 were detected for environment 2. Among these, five major (51.30, 48.70, 28.60, 56.00, 52.00 > 10 R2 ) and one minor (5.40 < 10 R2 ) QTLs for environment 1 and four major (51.48, 50.20, 53.00, 48.00 > 10 R2 ) and one minor (4.44 < 10) QTLs for environment 2 for Zn deficiency tolerance with a logarithm of odd threshold value higher than 3 were identified. The QTLs (qLB-4B, qPM-4B, qRZC-4B, qSZC-4B, qLB-4 N, qPM-4 N, qRZC-4 N, qSZC-4 N) for leaf bronzing, plant mortality root zinc concentration and shoot zinc concentration identified on chromosome 4 were found to be the most promising and highly reproducible across the locations that explained phenotypic variation from 48.00% to 56.00% with the same marker interval RM6748-RM303. CONCLUSION: The new QTLs and its linked markers identified in the present study can be utilized for Zn deficiency tolerance in elite cultivars using marker-assisted backcrossing. © 2022 Society of Chemical Industry.

Prevalence of Dysnatremia in Pulmonary Tuberculosis.

Pulmonary tuberculosis is one of the common diseases with high prevalence of mortality and morbidity in developing countries. It is one of the rare pulmonary infections which can induce hyponatremia and it is important to recognise hyponatremia because of its potential hazards. OBJECTIVES: To assess the serum sodium levels in patients with pulmonary tuberculosis and to establish a relation between the serum sodium levels and its effect on illness in these patients. MATERIAL: This is a single-center prospective observational Study conducted on patients with Pulmonary Tuberculosis, irrespective of treatment, in the department of General Medicine, B. R. Ambedkar Medical College, Bangalore from August 2019 to June 2021after obtaining ethical clearance. A total of 100 patients were enrolled in the study who met the predefined inclusion criteria of age more than 18 years and having been diagnosed with active tuberculosis. The collected data was analysed using student's T test and Chi-Square Test and the analysis was done using SPSS software version 24.0. OBSERVATION: The mean age was 46.46+/- 15.69, with majority of participants in the age group 46-60 years. Gender wise there was male preponderance in our study with 60%. The average serum sodium concentration in our study was 134.20 +/- 5.59 mmol/l, with 44% prevalence of hyponatremia and 4% SIADH Conclusion: Although mild hyponatremia was seen in more than 50% of patients, we found out that hyponatremia in pulmonary tuberculosis is detected in 44% of our patients with male preponderance. The predominant mechanism of hyponatremia was syndrome of inappropriate anti- diuretic hormone secretion (SIADH), which was present in 65% of cases with hyponatremia. Early detection and treatment of underlying electrolyte abnormality can potentially reduce mortality and morbidity associated with tuberculosis and reduce duration of hospitalization. Further research into the prevalence of potassium, magnesium and chloride abnormalities can add to the lacunae of knowledge.

The white beam station at imaging beamline BL-4, Indus-2.

The high flux density of synchrotron white beam offers several advantages in X-ray imaging such as higher resolution and signal-to-noise ratio in 3D/4D micro-tomography, higher frame rate in real-time imaging of transient phenomena, and higher penetration in thick and dense materials especially at higher energies. However, these advantages come with additional challenges to beamline optics, camera and sample due to increased heat load and radiation damage, and to personal safety due to higher radiation dose and ozone gas hazards. In this work, a white beam imaging facility at imaging beamline BL-4, Indus-2, has been developed, while taking care of various instrumental and personal safety challenges. The facility has been tested to achieve 1.5 µm spatial resolution, increased penetration depth up to 900 µm in steel, and high temporal resolutions of ∼10 ms (region of interest 2048 × 2048 pixels) and 70 µs (256 × 2048 pixels). The facility is being used successfully for X-ray imaging, non-destructive testing and dosimetry experiments.

Magnetopriming effects on arsenic stress-induced morphological and physiological variations in soybean involving synchrotron imaging.

This study investigates the effect of static magnetic field (SMF) pre-treatment in ameliorating arsenic (As) toxicity in soybean plants in relation to growth, photosynthesis and water transport through leaf venation. Soybean (Glycine max variety JS-9560) seeds pre-treated with SMF (200 mT for 1 h) were grown in four levels of arsenate-polluted soil (As(V); 0, 5, 10 and 50 mg kg-1 ) in order to find out the impact of magnetopriming on plant tolerance against As toxicity. Quantitative image analysis of soybean leaf venation showed a narrowing in the width of midrib with increasing As(V) contamination in non-primed seeds. The morphological variations are also supported by the physiological parameters such as reduction in efficiency of photosystem II, plant performance index, stomatal conductance and photosynthetic rate in the presence of As(V) for non-primed seeds. However, remarkable increase was observed in all the measured parameters by SMF pre-treatment at all the concentrations of As(V) used. Even for the highest concentration of As(V) (50 mg kg-1 soil), SMF pre-treatment caused significant enhancement in plant height (40%), area of third trifoliate leaves (40%), along with increase in width of the midrib (17%) and minor vein (13%), contributing to increase in the water uptake, that resulted in higher primary photochemistry of PSII (12%), performance index (50%), stomatal conductance (57%) and photosynthetic rate (33%) as compared to non-primed ones. Consequently, magnetopriming of dry seeds can be effectively used as pretreatment for reduction of As toxicity in soybean plants.

Prediction of Soil Clay Content and Cation Exchange Capacity Using Visible Near-Infrared Spectroscopy, Portable X-ray Fluorescence, and X-ray Diffraction Techniques.

This article investigates a novel data fusion method to predict clay content and cation exchange capacity using visible near-infrared (visNIR) spectroscopy, portable X-ray fluorescence (pXRF), and X-ray diffraction (XRD) techniques. A total of 367 soil samples from two study areas in regional Australia were analyzed and intra- and interarea calibration options were explored. Cubist models were constructed using information from each device independently and in combination. pXRF produced the most accurate predictions of any individual device. Models based on fused data significantly improved the accuracy of predictions compared with those based on individual devices. The combination of pXRF and visNIR had the greatest performance. Overall, the relative increase in Lin's concordance correlation coefficient ranged from 1% to 12% and the corresponding decrease in root-mean-square error (RMSE) ranged from 10% to 46%. Provision of XRD data resulted in a decrease in observed RMSE values, although differences were not significant. Validation metrics were less promising when models were calibrated in one study area and then transferred to the other. Observed RMSE values were ∼2 to 3 times larger under this model transfer scenario and independent use of XRD was found to have the best overall performance.

WRKY transcription factors and plant defense responses: latest discoveries and future prospects.

KEY MESSAGE: WRKY transcription factors are among the largest families of transcriptional regulators. In this review, their pivotal role in modulating various signal transduction pathways during biotic and abiotic stresses is discussed. Transcription factors (TFs) are important constituents of plant signaling pathways that define plant responses against biotic and abiotic stimuli besides playing a role in response to internal signals which coordinate different interacting partners during developmental processes. WRKY TFs, deriving their nomenclature from their signature DNA-binding sequence, represent one of the largest families of transcriptional regulators found exclusively in plants. By modulating different signal transduction pathways, these TFs contribute to various plant processes including nutrient deprivation, embryogenesis, seed and trichome development, senescence as well as other developmental and hormone-regulated processes. A growing body of research suggests transcriptional regulation of WRKY TFs in adapting plant to a variety of stressed environments. WRKY TFs can regulate diverse biological functions from receptors for pathogen triggered immunity, modulator of chromatin for specific interaction and signal transfer through a complicated network of genes. Latest discoveries illustrate the interaction of WRKY proteins with other TFs to form an integral part of signaling webs that regulate several seemingly disparate processes and defense-related genes, thus establishing their significant contributions to plant immune response. The present review starts with a brief description on the structural characteristics of WRKY TFs followed by the sections that present recent evidence on their roles in diverse biological processes in plants. We provide a comprehensive overview on regulatory crosstalks involving WRKY TFs during multiple stress responses in plants and future prospects of WRKY TFs as promising molecular diagnostics for enhancing crop improvement.

Current status of genomic resources on wild relatives of rice.

Rice is a food crop of global importance, cultivated in diverse agro-climatic zones of the world. However, in the process of domestication many beneficial alleles have been eroded from the gene pool of the rice cultivated globally and eventually has made it vulnerable to a plethora of stresses. In contrast, the wild relatives of rice, despite being agronomically inferior, have inherited a potential of surviving in a range of geographical habitats. These adaptations enrich them with novel traits that upon introgression to modern cultivated varieties offer tremendous potential of increasing yield and adaptability. But, due to the unavailability of their genetic as well as genomic resources, identification and characterisation of these novel beneficial alleles has been a challenging task. Nevertheless, with the unprecedented surge in the area of conservation genomics, researchers have now shifted their focus towards these natural repositories of beneficial traits. Presently, there are several generic and specialized databases harboring genome-wide information on wild species of rice, and are acting as a useful resource for identification of novel genes and alleles, designing of molecular markers, comparative analysis and evolutionary biology studies. In this review, we introduce the key features of these databases focusing on their utility in rice breeding programs.

Surface plasmon band tailoring of plasmonic nanostructure under the effect of water radiolysis by synchrotron radiation.

Plasmonic metal nanostructures have a significant impact on a diverse domain of fields, including photocatalysis, antibacterial, drug vector, biosensors, photovoltaic cell, optical and electronic devices. Metal nanoparticles (MNps) are the simplest nanostructure promising ultrahigh stability, ease of manufacturing and tunable optical response. Silver nanoparticles (AgNp) dominate in the class of MNps because of their relatively high abundance, chemical activity and unique physical properties. Although MNps offer the desired physical properties, most of the synthesis and fabrication methods lag at the electronic grade due to an unbidden secondary product as a result of the direct chemical reduction process. In this paper, a facile protocol is presented for fabricating high-yield in situ plasmonic AgNps under monochromatic X-rays irradiation, without the use of any chemical reducing agent which prevents the formation of secondary products. The ascendancy of this protocol is to produce high quantitative yield with control over the reaction rate, particle size and localized surface plasmon resonance response, and also to provide the feasibility for in situ characterization. The role of X-ray energy, beam flux and integrated dose towards the fabrication of plasmonic nanostructures has been studied. This experiment extends plasmonic research and provides avenues for upgrading production technologies of MNps.

Aging Induced Changes in Biochar's Functionality and Adsorption Behavior for Phosphate and Ammonium.

Biochar, a form of pyrogenic carbon, can contribute to agricultural and environmental sustainability by increasing soil reactivity. In soils, biochar could change its role over time through alterations in its surface chemistry. However, a mechanistic understanding of the aging process and its role in ionic nutrient adsorption and supply remain unclear. Here, we aged a wood biochar (550 °C) by chemical oxidation with 5-15% H2O2 and investigated the changes in surface chemistry and the adsorption behavior of ammonium and phosphate. Oxidation changed the functionality of biochar with the introduction of carboxylic and phenolic groups, a reduction of oxonium groups and the transformation of pyridine to pyridone. After oxidation, the adsorption of ammonium increased while phosphate adsorption decreased. Ammonium adsorption capacity was nonlinearly related to the biochar's surface charge density (r2 = 0.94) while electrostatic repulsion and loss of positive charge due to destruction of oxonium and pyridine, possibly caused the reduced phosphate adsorption. However, the oxidized biochar substantially adsorbed both ammonium and phosphate when biochar derived organic matter (BDOM) was included. Our results suggest that aging of biochar could reverse its capacity for the adsorption of cationic and anionic species but the inclusion of BDOM could increase ionic nutrient and contaminant retention.

Soil carbon and nitrogen stocks in forests along an altitudinal gradient in the eastern Himalayas and a meta-analysis of global data.

High-altitude soils potentially store a large pool of carbon (C) and nitrogen (N). The assessment of total C and N stocks in soils is vital to understanding the C and N dynamics in terrestrial ecosystems. In this study, we examined effects of altitude and forest composition on soil C and N along a transect from 317 to 3300 m a.s.l. in the eastern Himalayas. We used meta-analysis to establish the context for our results on the effects of altitude on soil C, including variation with depth. Total C and N contents of soils significantly increased with altitude, but decreased with soil depth. Carbon and N were similarly correlated with altitude and temperature, and temperature was seemingly the main driver of soil C along the altitudinal gradient. Altitude accounted for 73% of the variation in C and 47% of the variation in N stocks. Soil pH and cation exchange capacity were correlated with both soil C and N stocks. Increases in soil C and N stocks were related to forest composition, forest basal area as well as quantity of leaf litter that were in turn influenced by altitude and temperature. Concentrations of C in foliage increased by 2.1% for every 1000 m rise in altitude, while that in leaf litter increased by 2.3%.

Haplotype distribution and association of candidate genes with salt tolerance in Indian wild rice germplasm.

KEY MESSAGE: The association of natural genetic variations of salt-responsive candidate genes belonging to different gene families with salt-tolerance phenotype and their haplotype variation in different geographic regions. Soil salinity covers a large part of the arable land of the world and is a major factor for yield losses in salt-sensitive crops, such as rice. Different gene families that respond to salinity have been identified in rice, but limited success has been achieved in developing salt-tolerant cultivars. Therefore, 21 salt stress-responsive candidate genes belonging to different gene families were re-sequenced to analyse their genetic variation and association with salt tolerance. The average single nucleotide polymorphism (SNP) density was 16 SNPs per kbp amongst these genes. The identified nucleotide and haplotype diversity showed comparatively higher genetic variation in the transporter family genes. Linkage disequilibrium (LD) analysis showed significant associations of SNPs in BADH2, HsfC1B, MIPS1, MIPS2, MYB2, NHX1, NHX2, NHX3, P5CS1, P5CS2, PIP1, SIK1, SOS1, and SOS2 genes with the salt-tolerant phenotype. A combined analysis of SNPs in the 21 candidate genes and eight other HKT transporter genes produced two separate clusters of tolerant genotypes, carrying unique SNPs in the ion transporter and osmoticum-related genes. Haplotype network analysis showed all the major and few minor alleles distributed over distant geographic regions. Minor haplotypes may be recently evolved alleles which migrated to distant geographic regions and may represent recent expansion of Indian wild rice. The analysis of genetic variation in different gene families identified the relationship between adaptive variations and functional significance of the genes. Introgression of the identified alleles from wild relatives may enhance the salt tolerance and consequently rice production in the salinity-affected areas.

Natural allelic diversity in OsDREB1F gene in the Indian wild rice germplasm led to ascertain its association with drought tolerance.

KEY MESSAGE: Three coding SNPs and one haplotype identified in the OsDREB1F gene have potential to be associated with drought tolerance in rice. Drought is a serious constraint to rice production worldwide, that can be addressed by deployment of drought tolerant genes. OsDREB1F, one of the most potent drought tolerance transcription activator genes, was re-sequenced for allele mining and association study in a set of 136 wild rice accessions and four cultivated rice. This analysis led to identify 22 SNPs with eight haplotypes based on allelic variations in the accessions used. The nucleotide variation-based neutrality tests suggested that the OsDREB1F gene has been subjected to purifying selection in the studied set of rice germplasm. Six different OsDREB1F protein variants were identified on the basis of translated amino acid residues amongst the orthologues. Five protein variants were truncated due to deletions in coding region and found susceptible to drought stress. Association study revealed that three coding SNPs of this gene were significantly associated with drought tolerance. One OsDREB1F variant in the activation domain of OsDREB1F gene which led to conversion of aspartate amino acid to glutamate was found to be associated with drought tolerance. Three-dimensional homology modeling assisted to understand the functional significance of this identified potential allele for drought tolerance in rice. The natural allelic variants mined in the OsDREB1F gene can be further used in translational genomics for improving the water use efficiency in rice.

Genomics-assisted breeding in four major pulse crops of developing countries: present status and prospects.

KEY MESSAGE: Given recent advances in pulse molecular biology, genomics-driven breeding has emerged as a promising approach to address the issues of limited genetic gain and low productivity in various pulse crops. The global population is continuously increasing and is expected to reach nine billion by 2050. This huge population pressure will lead to severe shortage of food, natural resources and arable land. Such an alarming situation is most likely to arise in developing countries due to increase in the proportion of people suffering from protein and micronutrient malnutrition. Pulses being a primary and affordable source of proteins and minerals play a key role in alleviating the protein calorie malnutrition, micronutrient deficiencies and other undernourishment-related issues. Additionally, pulses are a vital source of livelihood generation for millions of resource-poor farmers practising agriculture in the semi-arid and sub-tropical regions. Limited success achieved through conventional breeding so far in most of the pulse crops will not be enough to feed the ever increasing population. In this context, genomics-assisted breeding (GAB) holds promise in enhancing the genetic gains. Though pulses have long been considered as orphan crops, recent advances in the area of pulse genomics are noteworthy, e.g. discovery of genome-wide genetic markers, high-throughput genotyping and sequencing platforms, high-density genetic linkage/QTL maps and, more importantly, the availability of whole-genome sequence. With genome sequence in hand, there is a great scope to apply genome-wide methods for trait mapping using association studies and to choose desirable genotypes via genomic selection. It is anticipated that GAB will speed up the progress of genetic improvement of pulses, leading to the rapid development of cultivars with higher yield, enhanced stress tolerance and wider adaptability.

Quantitative phase contrast X-ray tomography of aluminium metal matrix composite.

The quantitative assessment of micro-structure and load-induced damages in Al-SiC metal matrix composites (MMC) is important for its design optimization, performance evaluation and structure-property correlation. X-ray Phase contrast micro-tomography is potentially used for evaluation of its 3 dimensional micro-structure manifested in the form of voids, cracks, embedded particles, and load-induced damages. However, the contrast between Al matrix and SiC particles is insufficient for their clear morphological identification and quantitative assessment. In the present study, we have proposed and applied single image-based phase retrieval as a pre-processing step to micro-tomography reconstruction for improved assessment of micro-structure and cohesion-induced damages in Al-SiC MMC. The advantages of applying different phase retrieval techniques in the enhancement of image quality and morphological quantification of SiC particles, pores and cohesion damages are discussed. It is observed that the Paganin method offers the best improvement in contrast to noise ratio for the measurement of SiC particles embedded in the Al matrix.

Neutralizing antibodies from prior exposure to dengue virus negatively correlate with viremia on re-infection.

BACKGROUND: India is hyperendemic to dengue and over 50% of adults are seropositive. There is limited information on the association between neutralizing antibody profiles from prior exposure and viral RNA levels during subsequent infection. METHODS: Samples collected from patients with febrile illness was used to assess seropositivity by indirect ELISA. Dengue virus (DENV) RNA copy numbers were estimated by quantitative RT-PCR and serotype of the infecting DENV was determined by nested PCR. Focus reduction neutralizing antibody titer (FRNT) assay was established using Indian isolates to measure the levels of neutralizing antibodies and also to assess the cross-reactivity to related flaviviruses namely Zika virus (ZIKV), Japanese encephalitis virus (JEV) and West Nile virus (WNV). RESULTS: In this cross-sectional study, we show that dengue seropositivity increased from 52% in the 0-15 years group to 89% in >45 years group. Antibody levels negatively correlate with dengue RNAemia on the day of sample collection and higher RNAemia is observed in primary dengue as compared to secondary dengue. The geometric mean FRNT50 titers for DENV-2 is significantly higher as compared to the other three DENV serotypes. We observe cross-reactivity with ZIKV and significantly lower or no neutralizing antibodies against JEV and WNV. The FRNT50 values for international isolates of DENV-1, DENV-3 and DENV-4 is significantly lower as compared to Indian isolates. CONCLUSIONS: Majority of the adult population in India have neutralizing antibodies to all the four DENV serotypes which correlates with reduced RNAemia during subsequent infection suggesting that antibodies can be considered as a good correlate of protection.

India is one of the hotspots of dengue infection. The objective of the study was to assess whether having previous exposure to dengue virus could influence how the body will respond to repeat infections with dengue virus. Here, we analysed samples from febrile patients to measure the amount of dengue virus genetic material in the blood, the type of virus and the amount of antibodies, which are proteins produced by the host in response to dengue virus infection. The majority of patient samples demonstrated the capability to restrict all four types of dengue virus in circulation within the country, but reduced capacity to restrict when it comes to international dengue virus types. These data will help to inform future dengue vaccine design and clinical studies in India.

Ecotoxicological effects of plastics on plants, soil fauna and microorganisms: A meta-analysis.

The interactions of plastics and soil organisms are complex and inconsistent observations on the effects of plastics on soil organisms have been made in published studies. In this study, we assessed the effects of plastic exposure on plants, fauna and microbial communities, with a meta-analysis. Using a total of 2936 observations from 140 publications, we analysed how responses in plants, soil fauna and microorganisms depended on the plastic concentration, size, type, species and exposure media. We found that overall plastics caused substantial detrimental effects to plants and fauna, but less so to microbial diversity and richness. Plastic concentration was one of the most important factors explaining variations in plant and faunal responses. Larger plastics (>1 µm) caused unfavourable changes to plant growth, germination and oxidative stress, while nanoplastics (NPs; ≤ 1 µm) only increased oxidative stress. On the contrary, there was a clear trend showing that small plastics adversely affected fauna reproduction, survival and locomotion than large plastics. Plant responses were indifferent to plastic type, with most studies conducted using polyethylene (PE) and polystyrene (PS) plastics, but soil fauna were frequently more sensitive to PS than to PE exposure. Plant species played a vital role in some parameters, with the effects of plastics being considerably greater on vegetable plants than on cereal plants.

Pre-existing antibody levels negatively correlate with antibody titers after a single dose of BBV152 vaccination.

Many adults in India have received at least one dose of COVID-19 vaccine with or without a prior history SARS-CoV-2 infection. However, there is limited information on the effect of prior immunity on antibody response upon vaccination in India. As immunization of individuals continues, we aimed to assess whether pre-existing antibodies are further boosted by a single dose of BBV152, an inactivated SARS-CoV-2 vaccine, and, if these antibodies can neutralize SARS-CoV-2 Delta and Omicron variants. Here we show that natural infection during the second wave in 2021 led to generation of neutralizing antibodies against other lineages of SARS-CoV-2 including the Omicron variant, albeit at a significantly lower level for the latter. A single dose of BBV152 boosted antibody titers against the Delta and the Omicron variants but the antibody levels remained low against the Omicron variant. Boosting of antibodies showed negative correlation with baseline neutralizing antibody titers.

Virus-Like Particles of SARS-CoV-2 as Virus Surrogates: Morphology, Immunogenicity, and Internalization in Neuronal Cells.

The engineering of virus-like particles (VLPs) is a viable strategy for the development of vaccines and for the identification of therapeutic targets without using live viruses. Here, we report the generation and characterization of quadruple-antigen SARS-CoV-2 VLPs. VLPs were generated by transient transfection of two expression cassettes in adherent HEK293T cells─one cassette containing Mpro for processing of three structural proteins (M, E, and N), and the second cassette expressing the Spike protein. Further characterization revealed that the VLPs retain close morphological and antigenic similarity with the native virus and also bind strongly to the SARS-CoV-2 receptor hACE-2 in an in vitro binding assay. Interestingly, the VLPs were found to internalize into U87-MG cells through cholesterol-rich domains in a dynamin-dependent process. Finally, our results showed that mice immunized with VLPs induce robust humoral and cellular immune responses mediated by enhanced levels of IL-4, IL-17, and IFNγ. Taken together, our results demonstrate that VLPs mimic the native virus and induce a strong immune response, indicating the possible use of these particles as an alternative vaccine candidate against SARS-CoV-2. VLPs can also be effective in mapping the initial stages of virus entry and screening inhibitors.