Assessment of textile effluent treatment by immobilized Trametes pubescens MB 89 for plant growth promotion.

Industrialization and the ever-increasing world population have diminished high-quality water resources for sustainable agriculture. It is imperative to effectively treat industrial effluent to render the treated water available for crop cultivation. This study aimed to assess the effectiveness of textile effluent treated with Trametes pubescens MB 89 in supporting maize cultivation. The fungal treatment reduced the amounts of Co, Pb and As in the textile effluent. The biological oxygen demand, total dissolved solids and total suspended solids were within the permissible limits in the treated effluent. The data indicated that the irrigation of maize with fungal-treated textile effluent improved the growth parameters of the plant including root, shoot length, leaf area and chlorophyll content. Moreover, better antioxidant activity, total phenol content and protein content in roots, stems and leaves of maize plants were obtained. Photosynthetic parameters (potential quantum yield, electron transport rate and fluorescence yield of non-photochemical losses other than heat) were also improved in the plants irrigated with treated effluent as compared to the control groups. In conclusion, the treatment of textile effluent with the immobilized T. pubescens presents a sustainable solution to minimize chemical pollution and effectively utilize water resources.

Physiological and photochemical profiling of soybean plant using biological and chemical methods of treatment against biotic stress management.

Phyto-pathogenic fungal species is a leading biotic stress factor to agri-food production and ecosystem of globe. Chemical (Systemic fungicides) and biological treatment (micro-organism) are globally accepted methods that are being used against biotic stress (disease) management. Plant Growth-Promoting Microbes are being used as an alternative to ease chemical dependency as their overdoses have generated injurious effects on plants and environment. Therefore, present study performs to evaluate the photochemical and physiological profiling of plants exposed to chemical and biological treatment in biotic stress (disease) environment. Two concentrations of each chemical treatment i.e. Topsin-M 70 (Dimethyl 4,4'-o-phenylene bis 3-thioallaphanate, MF1 = 3 g kg-1 and MF2 = 6 g kg-1 seeds) and biological treatment i.e. Trichoderma harzianum strain Th-6 (MT1 = 106 spores mL-1and MT2 = 107 spores mL-1) were used in this experiment. Macrophomina phaseolina (MP) were used as biotic stress factor causing root rot disease in soybean plants. Morpho-physiological assessments and light harvesting efficiency of photosystem II were conducted after 52 days of treatment. Maximum quantum yield (Fv/Fm), number and size of active reaction center (Fv/Fo), photochemical quenching (qP), efficiency of photosystem II (ΦPSII), electron transport rate (ETR), chlorophyll content index (CCI), relative water content (RWC) and stomatal conductance (SC) were increased in MT2 and MF1 treatments as compared to stress plants (MP). Biological (MT2) and chemical (MF1) treatment lessen the production of stress markers showing -48.0 to -54.3% decline in malondialdehyde (MDA) and -42.0 to -53.7% in hydrogen peroxide (H2O2) as compared to stress plant (MP). Biological treatment in both concentration (MF1 & MF2) while chemical treatment at low dose effectively mitigates biotic stress and eases the magnitude of disease. Increasing doses of chemical treatment persuaded deleterious effects on the physiology and light harvesting efficiency of stressed plant suggesting the role of biological treatment (T. harzianum) against biotic stress management in future of crop protection.

Algal macromolecular mediated synthesis of nanoparticles for their application against citrus canker for food security.

Citrus canker is a disease of economic importance and there are limited biocontrol agents available to mitigate it in an integrated manner. This study was conducted to combat citrus canker disease using biologically active nanoparticles (Ag, Cu and ZnO and 300, 900, 1200, and 1500 ppm) synthesized from macromolecules extracted from alga, Oedogonium sp. The synthesis of the nanoparticles was confirmed by UV-Vis Spectroscopy, FTIR, SEM, XRD, and DLS Zeta sizer while their efficacy was tested against Xanthomonas citri by measuring zone of inhibition. Results indicated that Ag and Cu nanoparticles at 1200 ppm exhibit the highest activity against Xanthomonas citri, followed by ZnO at 1500 ppm. The minimum inhibitory concentrations (MIC) of Ag, Cu and ZnO NPs were 1, 2 and 10 mg mL-1, respectively while minimum bactericidal concentrations (MBC) were for Ag and Cu 2, 4 mg mL-1 and for ZnO NPs more then 10 mg mL-1, were required to kill the X. citri. Bacterial growth respectively. Macromolecules extracted from algal sources can produce nanoparticles with bactericidal potential, in the order of Ag > Cu > ZnO to mitigate citrus canker disease and ensuring sustainable food production amid the growing human population.

The potential of zeolite nanocomposites in removing microplastics, ammonia, and trace metals from wastewater and their role in phytoremediation.

Nanocomposites are emerging as a new generation of materials that can be used to combat water pollution. Zeolite-based nanocomposites consisting of combinations of metals, metal oxides, carbon materials, and polymers are particularly effective for separating and adsorbing multiple contaminants from water. This review presents the potential of zeolite-based nanocomposites for eliminating a range of toxic organic and inorganic substances, dyes, heavy metals, microplastics, and ammonia from water. The review emphasizes that nanocomposites offer enhanced mechanical, catalytic, adsorptive, and porosity properties necessary for sustainable water purification techniques compared to individual composite materials. The adsorption potential of several zeolite-metal/metal oxide/polymer-based composites for heavy metals, anionic/cationic dyes, microplastics, ammonia, and other organic contaminants ranges between approximately 81 and over 99%. However, zeolite substrates or zeolite-amended soil have limited benefits for hyperaccumulators, which have been utilized for phytoremediation. Further research is needed to evaluate the potential of zeolite-based composites for phytoremediation. Additionally, the development of nanocomposites with enhanced adsorption capacity would be necessary for more effective removal of pollutants.

Enhancing tomato plant growth in a saline environment through the eco-friendly synthesis and optimization of nanoparticles derived from halophytic sources.

Using green synthesis methods to produce halophytic nanoparticles presents a promising and cost-effective approach for enhancing plant growth in saline environments, offering agricultural resilience as an alternative to traditional chemical methods. This study focuses on synthesizing zinc oxide (ZnO) nanoparticles derived from the halophyte Withania somnifera, showcasing their potential in ameliorating tomato growth under salinity stress. The biosynthesis of ZnO nanoparticles was initially optimized (i.e., salt concentration, the amount of plant extract, pH, and temperature) using a central composite design (CCD) of response surface methodology (RSM) together with UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and dynamic light scattering (DLS) to comprehensively characterize the biosynthesized ZnO NPs. The central composite design (CCD) based response surface methodology (RSM) was used to optimize the biosynthesis of ZnO nanoparticles (NPs) by adjusting salt concentration, plant extract, pH, and temperature. The ZnO NPs were characterized using UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and dynamic light scattering (DLS). FT-IR showed an absorption peak of ZnO between 400 and 600 cm-1, while SEM showed irregular shapes ranging between 1.3 and 6 nm. The data of EDX showed the presence of Zn (77.52%) and O (22.48%) levels, which exhibited the high purity synthesized ZnO under saline conditions. Introducing ZnO nanoparticles to tomato plants resulted in a remarkable 2.3-fold increase in shoot length in T23 (100 mg/L ZnO nanoparticles + 50 mM NaCl). There was an observable increase in foliage at T2 (20 mg L-1 ZnO) and T23 (100 mg L-1 ZnO-NPs + 50 mM NaCl). Tomato plants treated with T2 (20 mg L-1 ZnO) and T23 (100 mg L-1 ZnO-NPs + 50 mM NaCl) improved root elongation compared to the control plant group. Both fresh and dry leaf masses were significantly improved in T1 (10 mg L-1 ZnO) by 7.1-fold and T12 (10 mg L-1 ZnO-NPs + 100 mM NaCl) by 0.8-fold. The concentration of Zn was higher in T12 (10 mg L-1 ZnO NPs + 100 mM NaCl) among all treatments. Our findings prove that utilizing ZnO nanoparticles under saline conditions effectively promotes tomato plants' growth, thereby mitigating the negative impacts of salt stress.

Utilization of microalgal-bacterial energy nexus improves CO2 sequestration and remediation of wastewater pollutants for beneficial environmental services.

Carbon dioxide (CO2) emissions from the combustion of fossil fuels and coal are primary contributors of greenhouse gases leading to global climate change and warming. The toxicity of heavy metals and metalloids in the environment threatens ecological functionality, diversity and global human life. The ability of microalgae to thrive in harsh environments such as industrial wastewater, polluted lakes, and contaminated seawaters presents new, environmentally friendly, and less expensive CO2 remediation solutions. Numerous microalgal species grown in wastewater for industrial purposes may absorb and convert nitrogen, phosphorus, and organic matter into proteins, oil, and carbohydrates. In any multi-faceted micro-ecological system, the role of bacteria and their interactions with microalgae can be harnessed appropriately to enhance microalgae performance in either wastewater treatment or algal production systems. This algal-bacterial energy nexus review focuses on examining the processes used in the capture, storage, and biological fixation of CO2 by various microalgal species, as well as the optimized production of microalgae in open and closed cultivation systems. Microalgal production depends on different biotic and abiotic variables to ultimately deliver a high yield of microalgal biomass.

Exploring the bioremediation capability of petroleum-contaminated soils for enhanced environmental sustainability and minimization of ecotoxicological concerns.

The bioremediation of soils contaminated with petroleum hydrocarbons (PHCs) has emerged as a promising approach, with its effectiveness contingent upon various types of PHCs, i.e., crude oil, diesel, gasoline, and other petroleum products. Strategies like genetically modified microorganisms, nanotechnology, and bioaugmentation hold potential for enhancing remediation of polycyclic aromatic hydrocarbon (PAH) contamination. The effectiveness of bioremediation relies on factors such as metabolite toxicity, microbial competition, and environmental conditions. Aerobic degradation involves enzymatic oxidative reactions, while bacterial anaerobic degradation employs reductive reactions with alternative electron acceptors. Algae employ monooxygenase and dioxygenase enzymes, breaking down PAHs through biodegradation and bioaccumulation, yielding hydroxylated and dihydroxylated intermediates. Fungi contribute via mycoremediation, using co-metabolism and monooxygenase enzymes to produce CO2 and oxidized products. Ligninolytic fungi transform PAHs into water-soluble compounds, while non-ligninolytic fungi oxidize PAHs into arene oxides and phenols. Certain fungi produce biosurfactants enhancing degradation of less soluble, high molecular-weight PAHs. Successful bioremediation offers sustainable solutions to mitigate petroleum spills and environmental impacts. Monitoring and assessing strategy effectiveness are vital for optimizing biodegradation in petroleum-contaminated soils. This review presents insights and challenges in bioremediation, focusing on arable land safety and ecotoxicological concerns.

Seed enhancement technologies for sustainable dryland restoration: Coating and scarification.

High temperatures, soil salinity, a lack of available water, loose soils with reduced water holding, and low soil fertility are obstacles to restoration efforts in degraded drylands and desert ecosystems. Improved soil physical and chemical properties, seed germination and seedling recruitment, and plant growth are all proposed as outcomes of seed enhancement technologies (SETs). Seed priming, seed coating, and seed scarification are three SETs' methods for promoting seed germination and subsequent plant development under unfavorable environmental conditions. Various subtypes can be further classified within these three broad groups. The goals of this review are to (1) develop a general classification of coating and scarification SETs, (2) facilitate the decision-making process to adopt suitable SETs for arid lands environments, and (3) highlight the benefits of coating and scarification SETs in overcoming biotic and abiotic challenges in ecological restoring degraded dryland. For rehabilitating degraded lands and restoring drylands, it is recommended to 1) optimize SETs that have been used effectively for a long time, particularly those associated with seed physiological enhancement and seed microenvironment, 2) integrate coating and scarification to overcome different biotic and abiotic constraints, and 3) apply SET(s) to a mixture of seeds from various species and sizes. However, more research should be conducted on developing SETs for large-scale use to provide the required seed tonnages for dryland restoration.

Salt-Induced Modulation of Ion Transport and PSII Photoprotection Determine the Salinity Tolerance of Amphidiploid Brassicas.

Brassica species show varying levels of resistance to salt stress. To understand the genetics underlying these differential stress tolerance patterns in Brassicas, we exposed two widely cultivated amphidiploid Brassica species having different genomes, Brassica juncea (AABB, n = 18) and Brassica napus (AACC, n = 19), to elevated levels of NaCl concentration (300 mM, half the salinity of seawater). B. juncea produced more biomass, an increased chlorophyll content, and fewer accumulated sodium (Na+) and chloride (Cl-) ions in its photosynthesizing tissues. Chlorophyll fluorescence assays revealed that the reaction centers of PSII of B. juncea were more photoprotected and hence more active than those of B. napus under NaCl stress, which, in turn, resulted in a better PSII quantum efficiency, better utilization of photochemical energy with significantly reduced energy loss, and higher electron transport rates, even under stressful conditions. The expression of key genes responsible for salt tolerance (NHX1 and AVP1, which are nuclear-encoded) and photosynthesis (psbA, psaA, petB, and rbcL, which are chloroplast-encoded) were monitored for their genetic differences underlying stress tolerance. Under NaCl stress, the expression of NHX1, D1, and Rubisco increased several folds in B. juncea plants compared to B. napus, highlighting differences in genetics between these two Brassicas. The higher photosynthetic potential under stress suggests that B. juncea is a promising candidate for genetic modifications and its cultivation on marginal lands.

Potential of Halophytes as Sustainable Fodder Production by Using Saline Resources: A Review of Current Knowledge and Future Directions.

Good quality water and arable land are required for both domestic and agricultural uses. Increasing population leads to urbanization and industrialization increasing the need to share these resources and creating threats to the food supply. Higher meat consumption requires mitigation strategies to protect food and mitigate economic crises, especially in developing nations. The production of food crops for energy purposes and lower yield due to climate change increase food prices as well as have a negative impact on the economy. Thus, an alternative food source is required featuring high forage components to reduce grazing periods and to prevent rangeland degradation. Halophytes can tolerate high salinity and can be easily grown for fodder in coastal areas where fodder is a problem. Varied climate conditions offer opportunities to grow suitable halophytes for specific purposes. One important feature is their use as fodder. To reduce food shortages, saline areas could be used to grow nutritive and productive halophytic forage. Wild plants have undesirable metabolites produced in harsh conditions which may be harmful for ruminant health. Halophytes have moderate amounts of these metabolites which are nontoxic. Halophytes can be grown without intruding on agricultural lands and freshwater resources and could promote livestock production which may improve the socio-economic conditions of poor farmers in a sustainable and ecofriendly manner.

Potential use of saline resources for biofuel production using halophytes and marine algae: prospects and pitfalls.

There exists a global challenge of feeding the growing human population of the world and supplying its energy needs without exhausting global resources. This challenge includes the competition for biomass between food and fuel production. The aim of this paper is to review to what extent the biomass of plants growing under hostile conditions and on marginal lands could ease that competition. Biomass from salt-tolerant algae and halophytes has shown potential for bioenergy production on salt-affected soils. Halophytes and algae could provide a bio-based source for lignoceelusic biomass and fatty acids or an alternative for edible biomass currently produced using fresh water and agricultural lands. The present paper provides an overview of the opportunities and challenges in the development of alternative fuels from halophytes and algae. Halophytes grown on marginal and degraded lands using saline water offer an additional material for commercial-scale biofuel production, especially bioethanol. At the same time, suitable strains of microalgae cultured under saline conditions can be a particularly good source of biodiesel, although the efficiency of their mass-scale biomass production is still a concern in relation to environmental protection. This review summaries the pitfalls and precautions for producing biomass in a way that limits environmental hazards and harms for coastal ecosystems. Some new algal and halophytic species with great potential as sources of bioenergy are highlighted.

Exploring Views and Expectations of Clinicians, Nurses, and Kidney Transplant Recipients Regarding Protocol Development of a Study to Investigate Feasibility of the Implantable Doppler Probe in Kidney Transplantation: Patient-Public Involvement Consultations.

OBJECTIVES: The shortage of donor organs is the most limiting factor in kidney transplant practice today. New monitoring technologies are being investigated to reduce graft loss due to vascular complications. We assessed the feasibility of a novel blood flow monitoring device, the implantable Doppler probe, in kidney transplant surgery. This patient-public involvement consultation explored the views and expectations of the stakeholders (kidney transplant recipients, surgeons, clinicians, and nurses with direct experience of the implantable Doppler probe) on the protocol development of our feasibility study. Our objective was to improve the protocol, understand stakeholder perceptions regarding research in postoperative graft surveillance, and identify potential confounding factors to the research and challenges to implementation of implantable Doppler probe in clinical practice. MATERIALS AND METHODS: We conducted semi-structured interviews containing open-ended questions with 12 stakeholders. We performed thematic analysis of the data at the latent level by an inductive approach according to a 6-phase guide by Braun and Clarke using NVivo 12 software. RESULTS: Three key themes emerged. (1) Experiences with the implantable Doppler probe as a monitoring device showed that it was well received by the patients; however, there was a clinical equipoise among the health care professionals. (2) Recognition of the need for research in the early postoperative graft monitoring displayed stakeholder understanding regarding the role of a blood flow monitoring device to improve surgical outcomes. (3) Recommendations for smooth conduct of the proposed study include suggestions for improvement of the study protocol, informative sessions for the patients and nurses, and innovative ideas to improve the monitoring device. CONCLUSIONS: Patient-public involvement consultation was crucial for the research design of our proposed feasibility study. Useful strategies and a patient- centered approach were incorporated to mitigate the potential challenges to the conduct of the research.

Efficient detoxification of textile wastewater by applying Chenopodium album nanoparticles and its application in simulated metal-bearing effluents removal.

Large-scale pollution of water and soils bodies is associated with the discharge of the untreated textile industry effluents. Halophytes grows on saline lands and accumulate secondary metabolites and other stress protective compounds. Utilization of Chenopodium album (halophytes) to synthesize zinc oxide (ZnO) and their efficiency to treat different concentrations of textile industry waste water is proposed in this study. Potential of nanoparticles textile industry waste water effluents was also analyzed by exposing different concentrations of nanoparticles (0 (control), 0.2, 0.5, 1 mg) and time intervals of 5, 10, and 15 days. The absorption peaks by UV region, FTIR and SEM analysis were used characterized on ZnO NPs for the first time. FTIR analysis showed the preens of various functional groups and vital phytochemicals that can play its role in the formation of nanoparticles that can be used for trace elements removal and bioremediation. SEM analysis indicated that the pure ZnO NPs synthesis ranged from 30 to 57 nm. Results shows that the green synthesis of halophytic nanoparticles presents maximum removal capacity after 15 days exposure to 1 mg of ZnO NPs. Hence, the prepared ZnO Nps from halophytes can be a viable solution for treating the textile industry effluents before they are discharged into water bodies for sustainable environmental growth and environmental safety.

Phytoremediation of Potentially Toxic Elements from Contaminated Saline Soils Using Salvadora persica L.: Seasonal Evaluation.

Plants in coastal ecosystems are primarily known as natural sinks of trace metals and their importance for phytoremediation is well established. Salvadora persica L., a medicinally important woody crop of marginal coasts, was evaluated for the accumulation of metal pollutants (viz. Fe, Mn, Cu, Pb, Zn, and Cr) from three coastal areas of Karachi on a seasonal basis. Korangi creek, being the most polluted site, had higher heavy metals (HM's) in soil (Fe up to 17,389, Mn: 268, Zn: 105, Cu: 23, Pb: 64.7 and Cr up to 35.9 mg kg-1) and S. persica accumulated most of the metals with >1 TF (translocation factor), yet none of them exceeded standard permissible ranges except for Pb (up to 3.1 in roots and 3.37 mg kg-1 in leaves with TF = 11.7). Seasonal data suggested that higher salinity in Clifton and Korangi creeks during pre- and post-monsoon summers resulted in lower leaf water (ΨWo) and osmotic potential at full turgor (ΨSo) and bulk elasticity (ε), higher leaf Na+ and Pb but lower extractable concentrations of other toxic metals (Cr, Cu, and Zn) in S. persica. Variation in metal accumulation may be linked to metal speciation via specific transporters and leaf water relation dynamics. Our results suggested that S. persica could be grown on Zn, Cr and Cu polluted soils but not on Pb affected soils as its leaves accumulated higher concentrations than the proposed limits.

Biochar-plant interaction and detoxification strategies under abiotic stresses for achieving agricultural resilience: A critical review.

The unpredictable climatic perturbations, the expanding industrial and mining sectors, excessive agrochemicals, greater reliance on wastewater usage in cultivation, and landfill leachates, are collectively causing land degradation and affecting cultivation, thereby reducing food production globally. Biochar can generally mitigate the unfavourable effects brought about by climatic perturbations (drought, waterlogging) and degraded soils to sustain crop production. It can also reduce the bioavailability and phytotoxicity of pollutants in contaminated soils via the immobilization of inorganic and/or organic contaminants, commonly through surface complexation, electrostatic attraction, ion exchange, adsorption, and co-precipitation. When biochar is applied to soil, it typically neutralizes soil acidity, enhances cation exchange capacity, water holding capacity, soil aeration, and microbial activity. Thus, biochar has been was widely used as an amendment to ameliorate crop abiotic/biotic stress. This review discusses the effects of biochar addition under certain unfavourable conditions (salinity, drought, flooding and heavy metal stress) to improve plant resilience undergoing these perturbations. Biochar applied with other stimulants like compost, humic acid, phytohormones, microbes and nanoparticles could be synergistic in some situation to enhance plant resilience and survivorship in especially saline, waterlogged and arid conditions. Overall, biochar can provide an effective and low-cost solution, especially in nutrient-poor and highly degraded soils to sustain plant cultivation.

Recent progress in bio-mediated synthesis and applications of engineered nanomaterials for sustainable agriculture.

The ever-increasing demand for agricultural food products, medicine, and other commercial sectors requires new technologies for agricultural practices and promoting the optimum utilization of natural resources. The application of engineered nanomaterials (ENMs) enhance the biomass production and yield of food crop while resisting harmful environmental stresses. Bio-mediated synthesis of ENMs are time-efficient, low-cost, environmentally friendly, green technology. The precedence of using a bio-mediated route over conventional precursors for ENM synthesis is non-toxic and readily available. It possesses many active agents that can facilitate the reduction and stabilization processes during nanoparticle formation. This review presents recent developments in bio-mediated ENMs and green synthesis techniques using plants, algae, fungi, and bacteria, including significant contributions to identifying major ENM applications in agriculture with potential impacts on sustainability, such as the role of different ENMs in agriculture and their impact on different plant species. The review also covers the advantages and disadvantages of different ENMs and potential future research in this field.

Seed Endophyte bacteria enhance drought stress tolerance in Hordeum vulgare by regulating, physiological characteristics, antioxidants and minerals uptake.

Growth stimulating bacteria help remediate dry arid soil and plant stress. Here, Pseudomonas sp. and Pantoea sp. we used to study the stress ecology of Hordeum vulgare and the environmental impact of water deficit on soil characteristics, growth, photosynthesis apparatus, mineral acquisition and antioxidiant defense. Plants inoculated with Pseudomonas or Pantoea had significantly higher (about 2 folds) soil carbon flux (soil respiration), chlorophyll levels (18%), net photosynthetic rate (33% in Pantoea and 54% in Pseudomonas), (44%) stomatal conductance than uninoculated plants in stressed conditions. Both bacterial strains improved leaf growth (23-29%) and root development under well-watered conditions but reduced around (25%) root biomass under drought. Plants inoculated with Pseudomonas or Pantoea under drought also increased of about 27% leaf respiration and transpiration (48%) but decreased water use efficiency, photoinhibition (91%), and the risk of oxidative stress (ETR/A) (49%). Drought stress increased most of the studied antioxidant enzymatic activities in the plants inoculated with Pseudomonas or Pantoea, which reduce the membrane damage and protect plants form oxidative defenses. Drought stress increased K+ acquisition around 50% in both shoots inoculated with Pseudomonas or Pantoea relative to non-stressed plants. Plants inoculated with Pseudomonas or Pantoea increased shoot Na+ while root Na+ only increased in plants inoculated with Pseudomonas in stressed conditions. Drought stress increased shoot Mg2+ in plants inoculated with Pseudomonas or Pantoea but did not affect Ca2+ relative to non-stressed plants. Drought stress increased about 70% K+/Na+ ratio only in plants inoculated with Pseudomonas relative to non-stressed plants. Our results indicate that inoculating barley with the studied bacterial strains increases plant biomass and can therefore play a role in the environmental remediation of drylands for food production.

Biomass Production and Predicted Ethanol Yield Are Linked with Optimum Photosynthesis in Phragmites karka under Salinity and Drought Conditions.

Plant photosynthesis and biomass production are closely associated traits but critical to unfavorable environmental constraints such as salinity and drought. The relationships among stress tolerance, photosynthetic mechanisms, biomass and ethanol yield were assessed in Phragmites karka. The growth parameters, leaf gas exchange and chlorophyll fluorescence of P. karka were studied when irrigated with the control and 100 and 300 mM NaCl in a nutrient solution and water deficit conditions (drought, at 50% water holding capacity). The plant shoot fresh biomass was increased in the low NaCl concentration; however, it significantly declined in high salinity and drought. Interestingly the addition of low salinity increased the shoot biomass and ethanol yield. The number of tillers was increased at 100 mM NaCl in comparison to the control treatment. High salinity increased the photosynthetic performance, but there were no significant changes in drought-treated plants. The saturated irradiance (Is) for photosynthesis increased significantly in low salinity, but it declined (about 50%) in high salt-stressed and (about 20%) in drought-treated plants compared to the control. The rates of dark respiration (Rd) and compensation irradiance (Ic) were decreased significantly under all treatments of salinity and drought, with the exception of unchanged Rd values in the control and drought treatments. A-Ci curve analyses revealed a significant improvement in the Jmax, Vc, max, and triose-phosphate utilization (TPU) at lower salinity levels but decreased at 300 mM NaCl and drought treatments compared to the control. In the chlorophyll fluorescence parameters (Fv/Fm, maximum photochemical quantum yield of PSII, and Y(NO)), the non-photochemical yields were not affected under the salt and drought treatments, although an effective photochemical quantum yield (YII) and electron transport rate (ETR) were significantly enhanced in water deficit compared to control plants. P. karka regulates an efficient photosynthesis mechanism to grow in saline and arid areas and can therefore be used as a sustainable biofuel crop.

Nano-fertilizers: A sustainable technology for improving crop nutrition and food security.

Excessive use of synthetic fertilizers cause economic burdens, increasing soil, water and atmospheric pollution. Nano-fertilizers have shown great potential for their sustainable uses in soil fertility, crop production and with minimum or no environmental tradeoffs. Nano-fertilizers are of submicroscopic sizes, have a large surface area to volume ratio, can have nutrient encapsulation, and greater mobility hence they may increase plant nutrient access and crop yield. Due to these properties, nano-fertilizers are regarded as deliverable 'smart system of nutrients'. However, the problems in the agroecosystem are broader than existing developments. For example, nutrient delivery in different physicochemical properties of soils, moisture, and other agro-ecological conditions is still a challenge. In this context, the present review provides an overview of various uses of nanotechnology in agriculture, preference of nano-fertilizers over the conventional fertilizers, nano particles formation, mobility, and role in heterogeneous soils, with special emphasis on the development and use of chitosan-based nano-fertilizers.

Assessment of Heavy Metal Accumulation in Soil and Garlic Influenced by Waste-Derived Organic Amendments.

In South Asia, the high costs of synthetic fertilizers have imposed research on alternative nutrient inputs. We aimed to identify potential trace elements (PTE) present in some organic manure that might be a source of environmental pollutions and risk to public health following consumption. The study aims to evaluate how different organic waste (poultry waste, PW; press mud, PM; and farmyard manure, FYM) influences the heavy metal migration in soil, the accumulation in garlic, and their potential health risks. Organic waste caused a higher accumulation of certain metals (Zn, Cu, Fe, and Co), whereas Mn, Cd, Cr, and Pb were in lower concentrations in soil. Amendments of soil with PM revealed a higher accumulation of Cd, Cr, Fe, and Pb, whereas PW resulted in Cu and Zn accumulation in garlic. Treatment of soil with FYM exhibited higher metal concentration of Co and Mn. An environmental hazard indices study revealed that pollution load index (PLI) was highest for Cu following treatment with PM. The health risk index (HRI) was greater for Cd following amendment with PM. Maximum daily intake of metals (DIM) was observed for Zn after treatment with PW. The Pb exhibited maximum bioconcentration factor (BCF) in PM-amended plants. Based on these findings, we concluded that garlic grown on contaminated soil with organic waste may pose serious health hazards following consumption.