Unveiling the detrimental effects of polylactic acid microplastics on rice seedlings and soil health.

The environmental impact of biodegradable polylactic acid microplastics (PLA-MPs) has become a global concern, with documented effects on soil health, nutrient cycling, water retention, and crop growth. This study aimed to assess the repercussions of varying concentrations of PLA-MPs on rice, encompassing aspects such as growth, physiology, and biochemistry. Additionally, the investigation delved into the influence of PLA-MPs on soil bacterial composition and soil enzyme activities. The results illustrated that the highest levels of PLA-MPs (2.5%) impaired the photosynthesis activity of rice plants and hampered plant growth. Plants exposed to the highest concentration of PLA-MPs (2.5%) displayed a significant reduction of 51.3% and 47.7% in their root and shoot dry weights, as well as a reduction of 53% and 49% in chlorophyll a and b contents, respectively. The activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) in rice leaves increased by 3.1, 2.8, 3.5, and 5.2 folds, respectively, with the highest level of PLA-MPs (2.5%). Soil enzyme activities, such as CAT, urease, and dehydrogenase (DHA) increased by 19.2%, 10.4%, and 22.5%, respectively, in response to the highest level of PLA-MPs (2.5%) application. In addition, PLA-MPs (2.5%) resulted in a remarkable increase in the relative abundance of soil Proteobacteria, Nitrospirae, and Firmicutes by 60%, 31%, and 98.2%, respectively. These findings highlight the potential adverse effects of PLA-MPs on crops and soils. This study provides valuable insights into soil-rice interactions, environmental risks, and biodegradable plastic regulation, underscoring the need for further research.

Differential capacity of phragmites ecotypes in remediation of inorganic contaminants in coastal ecosystems: Implications for climate change.

Remediating inorganic pollutants is an important part of protecting coastal ecosystems, which are especially at risk from the effects of climate change. Different Phragmites karka (Retz) Trin. ex Steud ecotypes were gathered from a variety of environments, and their abilities to remove inorganic contaminants from coastal wetlands were assessed. The goal is to learn how these ecotypes process innovation might help reduce the negative impacts of climate change on coastal environments. The Phragmites karka ecotype E1, found in a coastal environment in Ichkera that was impacted by residential wastewater, has higher biomass production and photosynthetic pigment content than the Phragmites karka ecotypes E2 (Kalsh) and E3 (Gatwala). Osmoprotectant accumulation was similar across ecotypes, suggesting that all were able to successfully adapt to polluted marine environments. The levels of both total soluble sugars and proteins were highest in E2. The amount of glycine betaine (GB) rose across the board, with the highest levels being found in the E3 ecotype. The study also demonstrated that differing coastal habitats significantly influenced the antioxidant activity of all ecotypes, with E1 displaying the lowest superoxide dismutase (SOD) activity, while E2 exhibited the lowest peroxidase (POD) and catalase (CAT) activities. Significant morphological changes were evident in E3, such as an expansion of the phloem, vascular bundle, and metaxylem cell areas. When compared to the E3 ecotype, the E1 and E2 ecotypes showed striking improvements across the board in leaf anatomy. Mechanistic links between architectural and physio-biochemical alterations are crucial to the ecological survival of different ecotypes of Phragmites karka in coastal environments affected by climate change. Their robustness and capacity to reduce pollution can help coastal ecosystems endure in the face of persistent climate change.

Iron-modified biochar improves plant physiology, soil nutritional status and mitigates Pb and Cd-hazard in wheat (Triticum aestivum L.).

Environmental quality and food safety is threatened by contamination of lead (Pb) and cadmium (Cd) heavy metals in agricultural soils. Therefore, it is necessary to develop effective techniques for remediation of such soils. In this study, we prepared iron-modified biochar (Fe-BC) which combines the unique characteristics of pristine biochar (BC) and iron. The current study investigated the effect of pristine and iron modified biochar (Fe-BC) on the nutritional values of soil and on the reduction of Pb and Cd toxicity in wheat plants (Triticum aestivum L.). The findings of present study exhibited that 2% Fe-BC treatments significantly increased the dry weights of roots, shoots, husk and grains by 148.2, 53.2, 64.2 and 148%, respectively compared to control plants. The 2% Fe-BC treatment also enhanced photosynthesis rate, transpiration rate, stomatal conductance, intercellular CO2, chlorophyll a and b contents, by 43.2, 88.4, 24.9, 32.5, 21.4, and 26.7%, respectively. Moreover, 2% Fe-BC treatment suppressed the oxidative stress in wheat plants by increasing superoxide dismutase (SOD) and catalase (CAT) by 62.4 and 69.2%, respectively. The results showed that 2% Fe-BC treatment significantly lowered Cd levels in wheat roots, shoots, husk, and grains by 23.7, 44.5, 33.2, and 76.3%. Whereas, Pb concentrations in wheat roots, shoots, husk, and grains decreased by 46.4, 49.4, 53.6, and 68.3%, respectively. Post-harvest soil analysis showed that soil treatment with 2% Fe-BC increased soil urease, CAT and acid phosphatase enzyme activities by 48.4, 74.4 and 117.3%, respectively. Similarly, 2% Fe-BC treatment significantly improved nutrients availability in the soil as the available N, P, K, and Fe contents increased by 22, 25, 7.3, and 13.3%, respectively. Fe-BC is a viable solution for the remediation of hazardous Cd and Pb contaminated soils, and improvement of soil fertility status.

Risk assessment of toxic and hazardous metals in paddy agroecosystem by biochar-for bio-membrane applications.

Toxic and carcinogenic metal (loid)s, such arsenic (As) and cadmium (Cd), found in contaminated paddy soils pose a serious danger to environmental sustainability. Their geochemical activities are complex, making it difficult to manage their contamination. Rice grown in Cd and As-polluted soils ends up in people's bellies, where it can cause cancer, anemia, and the deadly itai sickness. Solving this issue calls for research into eco-friendly and cost-effective remediation technology to lower rice's As and Cd levels. This research delves deeply into the origins of As and Cd in paddy soils, as well as their mobility, bioavailability, and uptake mechanisms by rice plants. It also examines the current methods and reactors used to lower As and Cd contamination in rice. Iron-modified biochar (Fe-BC) is a promising technology for reducing As and Cd toxicity in rice, improving soil health, and boosting rice's nutritional value. Biochar's physiochemical characteristics are enhanced by the addition of iron, making it a potent adsorbent for As and Cd ions. In conclusion, Fe-BC's biomembrane properties make them an attractive option for remediating As- and Cd-contaminated paddy soils. More efficient mitigation measures, including the use of biomembrane technology, can be developed when sustainable agriculture practices are combined with these technologies.

In-situ physical and chemical remediation of Cd and Pb contaminated mine soils cultivated with Chinese cabbage: A three-year field study.

Soils pollution with heavy metals (HMs) is a serious concern due to their toxic effects on crop yield, crop quality, soil environment, and human health. In the current study, four stabilizers of calcium carbonate (CC), dolomite (DL), zeolite (ZL), and steel slag (SS) were applied to cadmium (Cd) and lead (Pb)-contaminated soils as in-situ chemical remediation techniques along with in-situ physical remediation techniques i.e. soil covering (SC) and soil dilution (SD) under real field conditions. For three years, Chinese cabbage (Brassica rapa L.) was grown on the amended fields to examine how the amendments impacted Cd and Pb uptake in plants. The stabilization efficiency of SS, CC, and SC were 75.7 %, 66.0 %, and 71.1 %, respectively, for Cd, and 55.6 %, 55.6 %, and 70.0 %, respectively, for Pb. Results indicated that stabilizer soil amendments significantly decreased the exchangeable (F1) and carbonates bound (F2) fractions of both Cd and Pb. For instance, F1 fraction of Cd decreased from 10.2 (control) to 1.8-2.9 % (with stabilizers). The stabilizers increased Chinese cabbage dry weight by 11.4-22.5 % and decreased Cd and Pb uptake by 67.4 % and 24 %, respectively. The results demonstrated that in-situ chemical remediation technique showed promising results and maintained its efficiency for more than 130 weeks. Current study indicated that chemical remediation of Cd and Pb contaminated soil is more effective and last longer than physical remediation.

Glutathione treatment suppresses the adverse effects of microplastics in rice.

Oryza sativa is grown worldwide and exhibit sensitivity to different stresses. Exponential increase in microplastics in agroecosystems is damaging and demand pragmatic strategies to protect growth and yield losses. We evaluated exogenous application of different doses of glutathione (GSH) for mediation of physiological traits of rice plants experiencing two different MPs i.e. PET and HDPE in root zone. All the rice seedlings exhibited MP-induced significant (P ≤ 0.001) growth inhibition compared to the control plants. GSH application (T3) significantly increased the shoot fresh weight (8.80%), root fresh weight (19.22%), shoot dry weight (13.705%), root dry weight (25.52%), plant height (5.75%) and 100-grain weight (9.36%), compared to control plants. GSH treated plants (T4) showed a recovery mechanism by managing the marginal rate of reduction of all photosynthetic and gas exchange attributes by showing 34.44, 20.98, 34.83, 42.16, 39.70, and 51.38% reduction for Chl-a, Chl-b, total cholophyll, photosynthetic rate (A), transpiration rate (E), and stomatal conductance (Gs), respectively, compared to control plants. Under 5 mg L-1 HDPE and PET, rice seedlings without GSH treatment responded in terms of increase in total soluble sugar, total free amino acid, glutathione, glutathione disulfide contents, while total soluble protein and ascorbic acid contents decreased significantly, compared with control plants. Corrleation matrix revealed positive relationship between GSH and improvement in studied attributes. Moreover, exogenous GSH improved rice growth and productivity to counter the negative role of MPs. This unique study examined the effects of GSH on rice plants growing in MP-contaminated media and revealed how exogenous GSH helps plants survive MP-stress.

Interactive effects of polystyrene microplastics and Pb on growth and phytochemicals in mung bean (Vigna radiata L.).

Interaction of different pollutants can aggravate hazards to biotic components in agroecosystems. Microplastics (MPs) are especially needed to be focused on because of their increasing use in life around the globe. We investigated the interactive impacts of polystyrene microplastics (PS-MP) and lead (Pb) on mung bean (Vigna radiata L.). Toxicity of MPs and Pb directly impeded V. radiata attributes. In combination i.e., M2P2 (40 µM Pb + 4.0 mg L-1 MPs) predominantly reduced the shoot root fresh and dry weights. \ Pb and PS-MP impaired the Rubisco activity and chlorophyll contents. The dose dependent relationship (M2P2) discomposed indole 3-acetic acid by 59.02%. Individual treatments P2 (40 µM Pb) and M2 (4.0 mg L-1 MPs) respectively instigated a decline (44.07% and 27.12%) in IBA, while ABA was elevated. M2 significantly enhanced the contents of Alanine (Ala), Arginine (Arg), Proline (Pro), and glycine (Gly) by 64.11%, 63%, and 54% compared to control. Lysine (Lys) and Valine (Val) presented a converse relationship with other amino acids. Except for control, a gradual decline in yield parameters were observed in individual and combined applications of PS-MP. Proximate composition of carbohydrates, lipids and proteins also reflected a clear decrease in these compounds after combined application of Pb and MPs. Although, individual doses caused a decline in these compounds but effect of combined doses Pb and PS-MP was highly significant. Our results demonstrated the toxicity effect of Pb and MP in V. radiata attributes that is mainly linked with cumulative physiological and metabolic perturbations. These collective negative impacts of different doses of MPs and Pb on V. radiata would certainly pose serious implications for humans.

Plant-soil-microbe interactions in maintaining ecosystem stability and coordinated turnover under changing environmental conditions.

Ecosystem functions directly depend upon biophysical as well as biogeochemical reactions occurring at the soil-microbe-plant interface. Environment is considered as a major driver of any ecosystem and for the distributions of living organisms. Any changes in climate may potentially alter the composition of communities i.e., plants, soil microbes and the interactions between them. Since the impacts of global climate change are not short-term, it is indispensable to appraise its effects on different life forms including soil-microbe-plant interactions. This article highlights the crucial role that microbial communities play in interacting with plants under environmental disturbances, especially thermal and water stress. We reviewed that in response to the environmental changes, actions and reactions of plants and microbes vary markedly within an ecosystem. Changes in environment and climate like warming, CO2 elevation, and moisture deficiency impact plant and microbial performance, their diversity and ultimately community structure. Plant and soil feedbacks also affect interacting species and modify community composition. The interactive relationship between plants and soil microbes is critically important for structuring terrestrial ecosystems. The anticipated climate change is aggravating the living conditions for soil microbes and plants. The environmental insecurity and complications are not short-term and limited to any particular type of organism. We have appraised effects of climate change on the soil inhabiting microbes and plants in a broader prospect. This article highlights the unique qualities of tripartite interaction between plant-soil-microbe under climate change.

Foliar application of silver nanoparticles mitigated nutritional and biochemical perturbations in chilli pepper fertigated with domestic wastewater.

Due to environmental pollution, crop growth and productivity are threatened at different levels. Recapitulation of changes in plant bodies due to water pollution and mitigating strategies reveal the need for précised actions to save crop losses. The present study was carried out to estimate modulations in growth, mineral homeostasis, and nutrient profile of fruits in Capsicum annum L. grown with three concentrations of wastewater (25, 50, 100%) and two levels of silver nanoparticles (40 and 80 mg/L AgNPs). It has been reported that ion accumulation patterns from wastewater clearly vary among crops. Our findings manifested that the application of AgNPs significantly improved the mineral ions in different plant tissues, that ultimately helped to improve growth. Highest improvements were recorded for root shoot P (316 and 197%) at T9 (80 mg/L AgNPs + normal water), while K (273 and 262%), Mg (638 and 916%), and Ca (148 and 273%), at T11 (80 mg/L AgNPs + 50% Wastewater), in comparison with control. Such reduction in elemental uptake that remain detrimental even at low concentrations positively correlates with growth and nutrition of Capsicum plants. Another facet of our observation is dose-dependent improvement in nutritive attributes of fruits i.e., crude fibers, proteins, and carbohydrates by AgNPs. T8 (40 mg/L AgNPs + 100% Wastewater), improved nutritional attributes such as P (55%), Mn (44%), Zn (38%), Carbohydrates (62%), Crude fat (38%), and Fibers (49%) as compared to control. Application of silver nanoparticles (AgNPs) combined with untreated wastewater (WW) reduced the hazards of contaminants in plants. The finding of the current study suggested that AgNPs are a cost-efficient and environment friendly material having the potential to mitigate harmful impacts of WW on plants.

An assessment of the efficacy of biochar and zero-valent iron nanoparticles in reducing lead toxicity in wheat (Triticum aestivum L.).

Soil heavy metal contamination is increasing rapidly due to increased anthropogenic activities. Lead (Pb) is a well-known human carcinogen causing toxic effects on humans and the environment. Its accumulation in food crops is a serious hazard to food security. Developing environment-friendly and cost-efficient techniques is necessary for Pb immobilization in the soil. A pot experiment was executed to determine the role of biochar (BC), zero-valent iron nanoparticles (n-ZVI), and zero-valent iron nanoparticles biochar composite (n-ZVI-BC) in controlling the Pb mobility and bioaccumulation in wheat (Triticum aestivum L.). The results showed that BC and n-ZVI significantly enhanced the wheat growth by increasing their photosynthetic and enzymatic activities. Among all the applied treatments, the maximum significant (p ≤ 0.05) improvement in wheat biomass was with the n-ZVI-BC application (T3). Compared to the control, the biomass of wheat roots, shoots & grains increased by 92.5, 58.8, and 49.1%, respectively. Moreover, the soil addition of T3 amendment minimized the Pb distribution in wheat roots, shoots, and grains by 33.8, 26.8, and 16.2%, respectively. The outcomes of this experiment showed that in comparison to control treatment plants, soil amendment with n-ZVI-BC (T3) increased the catalase (CAT), superoxide dismutase (SOD) activity by 49.8 and 31.1%, respectively, ultimately declining electrolyte leakage (EL), malondialdehyde (MDA) and hydrogen peroxide (H2O2) content in wheat by 38.7, 33.3, and 38%respectively. In addition, applied amendments declined the Pb mobility in the soil by increasing the residual Pb fractions. Soil amendment with n-ZVI-BC also increased the soil catalase (CAT), urease (UR), and acid phosphatase (ACP) activities by 68, 59, and 74%, respectively. Our research results provided valuable insight for the remediation of Pb toxicity in wheat. Hence, we can infer from our findings that n-ZVI-BC can be considered a propitious, environment friendly and affordable technique for mitigating Pb toxicity in wheat crop and reclamation of Pb polluted soils.

Kinetic and isotherms modeling of methyl orange and chromium (VI) onto hexagonal ZnO microstructures as a membrane for environmental remediation of wastewater.

Globally, contamination of water by dyes and heavy metals (HMs) is a serious environmental and public health problem due to their carcinogenic and mutagenic nature. It is incumbent to treat innocuously before discharge. It is the first time, hexagonal zinc oxide (ZnO) microstructure are being employeed as a membrane in the simultaneous removal of methyl orange (MO) and chromium (Cr (VI)) from the aqueous solution. The surface chemistry of hexagonal ZnO was characterized for morphology, surface functional groups, crystalline nature, and elemental composition by scanning electron microscope (SEM), Fourier transmission infrared spectroscopy (FTIR), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). Adsorption capacity and removal efficiency was determined by the laboratory batch adsorption experiments, while nonlinear, linear kinetics and isotherm models were fitted to experimental data to investigate the adsorption process. The results exhibited that the maximum adsorption capacity (qmax) of hexagonal ZnO from the Langmuir isotherm model was 80.39 mg g-1 and 84.10 mg g-1 for MO and Cr (VI) respectively. According to the modeling findings, linear langmuir fitted to the experimental data with R2 0.967 and 0.971 for both MO and Cr (VI) which indicates monolayer physical adsorption of both pollutants has taken place. Whereas, kinetic study showed nonlinear pseudo-second order with R2 0.989 and 0.986 for MO and Cr (VI) model best fitted with the experimental data. The values of thermodynamics parameters Gibbs free energy change ΔG°, heat of enthalpy ΔH° and, heat of entropy ΔS° indicate that spontaneous, endothermic, and irreversible adsorption reactions occurred. Overall, it is concluded from our observations that hexagonal ZnO has the potential to be used as an eco-friendly, cost-effective adsorbent for simultaneous remaoval of both MO and Cr (VI) from water. Findings of the current investigation provide valuable insights for the development of an inexpensive, effective and sustainable filtration method for the treatment of MO and Cr (VI) synergistically.

Mitigation of lead toxicity in Vigna radiata genotypes by silver nanoparticles.

Heavy metal (HM) contamination of the soil through anthropogenic activities influences the living systems and drastically impacts food chain. This study examined the application of silver nanoparticles (AgNPs) in two genotypes (G1 and G2) of Mung bean (Vigna radiata) for ameliorating the Pb toxicity. Different doses of Pb (0, 25, 50 µM) were differentially tackled by AgNPs with the aim of ameliorating the plant attributes. Both genotypes displayed statistically significant quantitative and qualitative modulations for Pb tolerance. In G2, the most prominent increase in plant height (43.79%), fresh biomass (49.56%) and total chlorophyll (20%) was observed at L2 (AgNPs 10 mg/L) in comparison with the control. Overall, photosynthetic rate was increased by 26% in G2 at L6 (AgNPs 25 mg/L + Pb 25 µM). In addition, the results presented 78.5% increase in water use efficiency of G2 while G1 experienced a maximum internal CO2 concentration (209.8%) at L8 (Pb 50 µM). AgNPs triggered balanced uptake of minerals and improved growth of Vigna genotypes. 50 µM Pb was most hazardous and caused maximum reduction in growth of Vigna plants along with a significant suppression in photosynthetic activity, increase in MDA (199.7%) in G1 and H2O2 (292.8%) in G2. In comparison to control, maximum superoxide dismutase (376%), peroxidase (659.8%) and catalase (9.3%) activity was observed in G2 at L11. The application of AgNPs substantially enhanced plant growth and helped them in surviving well in absence as well as presence of Pb. G2 genotype exhibited substantial tolerance capability and revealed less impairment in the studied attributes than G1 and treatment of AgNPs i.e. 25 mg/L was the best level that yielded best results in both genotypes. The results demonstrate that AgNPs mediate response(s) of plants under Pb stress and particularly contributed to HM tolerance of plants and thus showing great promise for use in phytoremediation.

Goethite modified biochar simultaneously mitigates the arsenic and cadmium accumulation in paddy rice (Oryza sativa) L.

Cadmium (Cd) and arsenic (As) contamination of paddy soils is a serious global issue because of the opposite geochemical behavior of Cd and As in paddy soils. Rice plant (Oryza sativa L.) cultivation in Cd- and As- contaminated paddy soil is regarded as one of the main dietary cause of Cd and As entry in human beings. This study aimed to determine the impact of goethite-modified biochar (GB) on bioavailability of both Cd and As in Cd- and As- polluted paddy soil. Contrary to control and biochar (BC) amendments, the application of GB amendments significantly impeded the accumulation of both Cd and As in rice plants. The results confirmed an obvious reduction in Cd and As content of rice grains by 85% and 77%, respectively after soil supplementation with GB 2% amendment. BC 3% application minimized the Cd uptake by 59% in the rice grains as compared to the control but exhibited a little impact on As accumulation in rice grains. Sequential extraction results displayed an increase in immobile Cd and As fractions of the soil by decreasing the bioavailable fractions of both elements after GB treatments. Fe-plaque formation on the root surfaces was significantly variable (P Ë‚ 0.05) among all the amendments. GB 2% treatment significantly increased the Fe content (10 g kg-1) of root Fe-plaque by 48%, which ultimately enhanced the sequestration of Cd and As by Fe-plaque and minimized the transport of Cd and As in rice plants. Moreover, GB treatments significantly changed the relative abundance of the microbial community in the rice rhizosphere and minimized the metal(loid)s mobility in the soil. The relative abundance of Acidobacteria, Firmicutes and Verrucomicrobia increased with GB 2% treatment while those of Bacteroidetes and Choloroflexi decreased. Our findings confirmed improvement in the rice grains quality regarding enhanced amino acid contents with GB application. Overall, the results of this study demonstrated that GB amendment simultaneously alleviated the Cd and As concentrations in edible parts of rice plant and provided a new valuable method to protect the public health by effectively remediating the co-occurrence of Cd and As in paddy soils.

Elucidating the distinct interactive impact of cadmium and nickel on growth, photosynthesis, metal-homeostasis, and yield responses of mung bean (Vigna radiata L.) varieties.

Contamination of soils with heavy metals (HMs) caused serious problems because plants tend to absorb HMs from the soil. In view of HM hazards to plants as well as agro-ecosystems, we executed this study to assess metal toxicity to mung bean (Vigna radiata) plants cultivated in soil with six treatment levels of cadmium (Cd) and nickel (Ni) and to find metal tolerant variety, i.e., M-93 (V1) and M-1(V2) with multifarious plant biochemical and physiological attributes. Increasing doses of Cd and Ni inhibited plant growth and photosynthesis and both varieties showed highly significant differences in the morpho-physiological attributes. V2 showed sensitivity to Cd and Ni treatments alone or in combination. Tolerance indices for attributes presented a declined growth of Vigna plants under HM stress accompanied by highly significant suppression in gas exchange characteristics. Of single element applications, the adverse effects on mung bean were more pronounced in Cd treatments. V1 showed much reduction in photosynthesis attributes except sub-stomatal CO2 concentration in all treatments compared to V2. The yield attributes, i.e., seed yield/plant and 100-seed weight, were progressively reduced in T5 for both varieties. In combination, we have observed increased mobility of Cd and Ni in both varieties. The results showed that water use efficiency (WUE) generally increased in all the treatments for both varieties compared to control. V2 exhibited less soluble sugars and free amino acids compared to V1 in all the treatments. Similarly, we recorded an enhanced total free amino acid contents in both varieties among all the metal treatments against control plants. We conclude that combinatorial treatment proved much lethal for Vigna plants, but V1 performed better than V2 in counteracting the adverse effects of Cd and Ni.

Spike glycoproteins: Their significance for corona viruses and receptor binding activities for pathogenesis and viral survival.

The recent outbreak of Covid-19 is posing a severe threat to public health globally. Coronaviruses (CoVs) are the largest known group of positive-sense RNA viruses surviving on an extensive number of natural hosts. CoVs are enveloped and non-segmented viruses with a size between 80 and 120 nm. CoV attachment to the surface receptor and its subsequent entrance into cells is mediated by Spike glycoprotein (S). For enhanced CoV entry and successful pathogenesis of CoV, proteolytic processing and receptor-binding act synergistically for induction of large-scale S conformational changes. The shape, size and orientation of receptor-binding domains in viral attachment proteins are well conserved among viruses of different classes that utilize the same receptor. Therefore, investigations unraveling the distribution of cellular receptors with respect to CoV entry, structural aspects of glycoproteins and related conformational changes are highly significant for understanding virus invasion and infection spread. We present the characteristic features of CoV S-Proteins, their significance for CoVs and related receptor binding activities for pathogenesis and viral survival. We are analyzing the novel role of S-protein of CoVs along with their interactive receptors for improving host immunity and decreasing infection spread. This is hoped that presented information will open new ways in tackling coronavirus, especially for the ongoing epidemic.

Physiological and biochemical response of wheat (Triticum aestivum) to TiO2 nanoparticles in phosphorous amended soil: A full life cycle study.

Nanoparticles (NPs) application in soil as nano-fertilizers to increase crop yield is getting attention due to their higher efficiency and less environmental risks. This study investigated the interactive effects of variable titanium dioxide nanoparticles (TiO2-NPs) levels (0, 30, 50 and 100 mg kg-1) superimposed to phosphorus (P) fertilizer application in soil at the rates of 0, 25 and 50 mg kg-1 on wheat crop. Physiological parameters of plants, their antioxidant enzymes activities (SOD, POD), and contents of crude protein, H2O2, MDA and metals/nutrients (Al, Ca, Mg, Fe, Zn and Cu) were measured. Data on physiological traits revealed that application of 50 mg kg-1 of TiO2-NPs without P fertilizer significantly enhanced the root and shoot length by 63 and 26%, respectively. Increased contents of nutrients in the shoots, viz., Ca (316%), Cu (296%), Al (171%) and Mg (187%) with 50 mg kg-1 TiO2-NPs treatment reflected improvement in crop growth and grain quality. Furthermore, P contents in plant tissues were raised up to 56% with 50 mg kg-1 of TiO2-NPs even in the absence of P fertilizer. In the soil, concentration of phytoavailable P was significantly increased up to 63.3% in the presence of 50 mg kg-1 TiO2-NPs as compared to control. Contents of crude protein in grain were also enhanced by 22.8% (at P50) and 17.4% (at P25) with 50 mg kg-1 TiO2-NPs application. Along with P application, TiO2-NPs triggered the activities of SOD (2.06-33.97%) and POD (up to 13.19%), and H2O2 production (50.6-138.8%). However, MDA contents were not elevated significantly at any level of TiO2-NPs, and remained at par with control. It was noteworthy that highest level of TiO2-NPs, viz., 100 mg kg-1 exhibited plant and nutrients response lower than that with 50 mg kg-1. Further, TiO2-NPs triggered the bioavailability of micronutrient heavy metals (Zn, Cu and Fe) and Al, which could have toxicity at higher concentrations. These results suggested that TiO2-NPs might have some affinities with phosphate compounds and metal ions in the soil to bring them in soluble form, which enhanced their bioavailability. Although it improved the crop yield and quality, but toxic or negative impact of TiO2-NPs was also apparent at higher dose. Therefore, investigations on the potential interactions of NPs with other nutrients and toxic metals are needed to enhance our understanding for the safer application of nano-fertilizer.

Elicitins as molecular weapons against pathogens: consolidated biotechnological strategy for enhancing plant growth.

To fight against pathogens, defense systems in plants mainly depend upon preformed as well as induced responses. Pathogen detection activates induced responses and signals are transmitted for coordinated cellular events in order to restrict infection and spread. In spite of significant developments in manipulating genes, transcription factors and proteins for their involvement in immunity, absolute tolerance/resistance to pathogens has not been seen in plants/crops. Defense responses, among diverse plant types, to different pathogens involve modifications at the physio-biochemical and molecular levels. Secreted by oomycetes, elicitins are small, highly conserved and sterol-binding extracellular proteins with PAMP (pathogen associated molecular patterns) functions and are capable of eliciting plant defense reactions. Belonging to multigene families in oomycetes, elicitins are different from other plant proteins and show a different affinity for binding sterols and other lipids. These function for sterols binding to catalyze their inter-membrane and intra- as well as inter-micelle transport. Importantly, elicitins protect plants by inducing HR (hypersensitive response) and systemic acquired resistance. Despite immense metabolic significance and the involvement in defense activities, elicitins have not yet been fully studied and many questions regarding their functional activities remain to be explained. In order to address multiple questions associated with the role of elicitins, we have reviewed the understanding and topical advancements in plant defense mechanisms with a particular interest in elicitin-based defense actions and metabolic activities. This article offers potential attributes of elicitins as the biological control of plant diseases and can be considered as a baseline toward a more profound understanding of elicitins.

Bioaccumulation of ytterbium oxide nanoparticles insinuate oxidative stress, inflammatory, and pathological lesions in ICR mice.

With the rapid development in nanoscience and nanotechnology, rare earth oxide nanomaterials (REO-NMs) have been increasingly used due to their unique physical and chemical characteristics. Despite the increasing applications of REO NPs, scarce information is available on their detrimental effects. In the current study, we investigate the toxic effect of ytterbium oxide nanoparticles (Yb2O3 NPs) in mouse model by using various techniques including inductively coupled plasma mass spectrometry (ICP-MS) analysis over 30 days of exposure. Furthermore, we elucidated lung lavage fluid of mice for biochemical and cytological analysis, and lung tissues for histopathology to interpret the NP side effects. We observed a significant concentration of Yb2O3 NPs accumulated in the lung, liver, kidney, and heart tissues. Similarly, increased bioaccumulation of Yb content was found in the olfactory bulb compared to other reigns of brain. The cytological analysis of bronchoalveolar lavage fluid (BALF) revealed a significant elevation in the percentage of neutrophils and lymphocytes. Biochemical analysis showed an instilled Yb2O3 NPs, showing signs of oxidative damage through up-regulation of 60-87% of MDA while down-regulation of 20-40% of GSH-PX and GSH content. The toxicity pattern was more evident from histopathological observations. These interpretations provide enough evidence of bioaccumulation of Yb2O3 NPs in mice tissues. Overall, our findings reveal that acute exposure of Yb2O3 NPs through intranasal inhalation may cause toxicity via oxidative stress, which leads to a chronic inflammatory response. Graphical abstract Graphical illustrations of experimental findings.

Goethite-modified biochar ameliorates the growth of rice (Oryza sativa L.) plants by suppressing Cd and As-induced oxidative stress in Cd and As co-contaminated paddy soil.

Co-contamination of soils with cadmium (Cd) and arsenic (As) in rice growing areas is a serious threat to environment and human health. Increase in soil Cd and As levels curtail the growth and development of rice plants by causing oxidative stress and reduction in photosynthetic activity. Therefore, it is necessary to formulate and evaluate different strategies for minimizing the Cd and As uptake in rice plant. We modified biochar (BC) with goethite and assessed the effects of goethite-modified biochar (GB) application on mitigating Cd and As stress in rice plant. Although BC supply to rice plants enhanced their performance in contaminated soil but application of different GB levels i.e.1.5% GB to the soil resulted in prominent improvements in physiological and biochemical attributes of rice plants grown in Cd and As co-contaminated paddy soil. It was observed that soil amendment with GB increased the plant growth, biomass, photosynthetic pigments, gas exchange attribute of rice plant and suppressed the oxidative stress in rice leaves and roots by increased antioxidant enzymes activities. Supplementing the soil with 1.5% GB incremented the iron plaque (Fe-plaque) formation and enhanced the Cd and As sequestration by Fe-plaque. Application of GB (1.5%) significantly improved the Fe content of Fe-plaque by 68.7%. Maximum Cd (1.57 mg kg-1) and As (0.85 mg kg-1) sequestration by Fe-plaque was observed with 1.5% GB treatment. Compared to the control, 1.5% GB treatment application prominently reduced the Cd content in the rice roots and shoots by 42.9%, and 56.7%, respectively and As content in the rice roots and shoots declined by 32.2%, 46.6%, respectively, compared to the control. These findings demonstrate that amending the soil with 1.5% GB can be a potential remediation strategy for checking Cd and As accumulation, reducing oxidative stress and increasing the growth of rice plant.