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We investigated the role of ascorbic acid (AsA) to alleviate nickel (Ni) induced adverse effects on growth and concentration of Ni, copper (Cu), and manganese (Mn) in hydroponically grown wheat varieties viz. Galaxy, Punjab-2011, and FSD-08. Plants were exposed to five levels of Ni viz. 0, 5, 10, 15, and 20Exploiting plant internal mechanisms with foliar application of different organic substances have widely been investigated to decrease metal accumulation and their adverse effects on plants. However, the differential response of different varieties to metal accumulation in response to foliar application of ascorbic acid is not well documented. This study was conducted to investigate the effect of exogenous application of ascorbic acid on growth response, the concentration of Ni, Cu, and Mn in three wheat varieties.

Cholera is deadly watery diarrhea caused by Vibro cholerae. Approximately 550,000 Pakistani children die each year due to waterborne illnesses including diarrhea. Vibro cholera bacterium strain O1eLtOR is a major cause of diarrhea in Pakistan. Since it is a waterborne bacteria, people relying on tap water (not filtered) are the most vulnerable to this disease. In current study, tap water was disinfected by using different concentrations of sodium dichloroisocyanurate (NADDC) to devise an effective and inexpensive method to make water safe for drinking. Different concentrations of NADDC were utilized to disinfect water and 1.2 mg of NADDC in 40 ml water was effective to disinfect water from bacterial colonies The experimental data is represented through the proposed mathematical model i.e. exponential decay model and statistical analysis of the generated data is also done. The graphical representation is also done to show the exponential decay of bacterial growth. The results of our study reveal that NADCC is an effective chemical agent to purify drinking water from Vibrio cholerae.

The effect of organic amendments on phytoavailability of nickel (Ni) and other metals in soil may change with time due to transformation of organic matter. We investigated the residual effect of or...

Background Photosynthesis is a key process in plants that is compromised by the oxygenase activity of Rubisco, which leads to the production of toxic compound phosphoglycolate that is catabolized by photorespiratory pathway. Transformation of plants with photorespiratory bypasses have been shown to reduce photorespiration and enhance plant biomass. Interestingly, engineering of a single gene from such photorespiratory bypasses has also improved photosynthesis and plant productivity. Although single gene transformations may not completely reduce photorespiration, increases in plant biomass accumulation have still been observed indicating an alternative role in regulating different metabolic processes. Therefore, the current study was aimed at evaluating the underlying mechanism (s) associated with the effects of introducing a single cyanobacterial glycolate decarboxylation pathway gene on photosynthesis and plant performance. Methods Transgenic Arabidopsis thaliana plants (GD, HD, OX) expressing independently cyanobacterial decarboxylation pathway genes i.e., glycolate dehydrogenase, hydroxyacid dehydrogenase, and oxalate decarboxylase, respectively, were utilized. Photosynthetic, fluorescence related, and growth parameters were analyzed. Additionally, transcriptomic analysis of GD transgenic plants was also performed. Results The GD plants exhibited a significant increase (16%) in net photosynthesis rate while both HD and OX plants showed a non-significant (11%) increase as compared to wild type plants (WT). The stomatal conductance was significantly higher (24%) in GD and HD plants than the WT plants. The quantum efficiencies of photosystem II, carbon dioxide assimilation and the chlorophyll fluorescence-based photosynthetic electron transport rate were also higher than WT plants. The OX plants displayed significant reductions in the rate of photorespiration relative to gross photosynthesis and increase in the ratio of the photosynthetic electron flow attributable to carboxylation reactions over that attributable to oxygenation reactions. GD, HD and OX plants accumulated significantly higher biomass and seed weight. Soluble sugars were significantly increased in GD and HD plants, while the starch levels were higher in all transgenic plants. The transcriptomic analysis of GD plants revealed 650 up-regulated genes mainly related to photosynthesis, photorespiratory pathway, sucrose metabolism, chlorophyll biosynthesis and glutathione metabolism. Conclusion This study revealed the potential of introduced cyanobacterial pathway genes to enhance photosynthetic and growth-related parameters. The upregulation of genes related to different pathways provided evidence of the underlying mechanisms involved particularly in GD plants. However, transcriptomic profiling of HD and OX plants can further help to identify other potential mechanisms involved in improved plant productivity.

Chromium (Cr) is an ecological poison and its concentration is reaching to lethal intensities in soil and plants by irrigating the soil with raw industrial effluents, particularly in developing nations like Pakistan. Poultry manure and gypsum are recognized for their capability to immobilize heavy metals in soils for plant uptake and filtering to ground water. The current trial was conducted under controlled conditions to evaluate the viability of poultry manure (PM) and gypsum applications to mitigate Cr toxicity in spinach grown-up in soil watered with textile effluent. The trial was designed in a completely randomized design (CRD) with three repetitions. The treatments were: T1 (Control), T2 (Poultry Manure @ 0.5%), T3 (Poultry Manure @ 1%), T4 (Gypsum @ 0.3%) and T5 (Gypsum @ 0.6%). Chromium uptake by shoots and roots of spinach were enhanced in control plants where only textile effluent was applied. Chromium uptake in roots was higher than shoots. Application of poultry manure and gypsum reduced the Cr toxicity. The shoot length and dry weight of spinach was higher where PM was incorporated @ 1% as compared to gypsum and control. The extent of Cr toxicity mitigation by PM application @ 1% was higher when compared with control. The outcomes of this investigation demonstrated that application of PM @ 1% to the soil could be utilized as a viable approach for diminishing Cr concentration in spinach plants in Crcontaminated soils irrigated with untreated textile effluents

Plants employ photosynthesis to produce sugars for supporting their growth. During photosynthesis, an enzyme Ribulose 1,5 bisphosphate carboxylase/oxygenase (Rubisco) combines its substrate Ribulose 1,5 bisphosphate (RuBP) with CO2 to produce phosphoglycerate (PGA). Alongside, Rubisco also takes up O2 and produce 2-phosphoglycolate (2-PG), a toxic compound broken down into PGA through photorespiration. Photorespiration is not only a resource-demanding process but also results in CO2 loss which affects photosynthetic efficiency in C3 plants. Here, we propose to circumvent photorespiration by adopting the cyanobacterial glycolate decarboxylation pathway into C3 plants. For that, we have integrated the cyanobacterial glycolate decarboxylation pathway into a kinetic model of C3 photosynthetic pathway to evaluate its impact on photosynthesis and photorespiration. Our results show that the cyanobacterial glycolate decarboxylation bypass model exhibits a 10% increase in net photosynthetic rate (A) in comparison with C3 model. Moreover, an increased supply of intercellular CO2 (Ci) from the bypass resulted in a 54.8% increase in PGA while reducing photorespiratory intermediates including glycolate (− 49%) and serine (− 32%). The bypass model, at default conditions, also elucidated a decline in phosphate-based metabolites including RuBP (− 61.3%). The C3 model at elevated level of inorganic phosphate (Pi), exhibited a significant change in RuBP (+ 355%) and PGA (− 98%) which is attributable to the low availability of Ci. Whereas, at elevated Pi, the bypass model exhibited an increase of 73.1% and 33.9% in PGA and RuBP, respectively. Therefore, we deduce a synergistic effect of elevation in CO2 and Pi pool on photosynthesis. We also evaluated the integrative action of CO2, Pi, and Rubisco carboxylation activity (Vcmax) on A and observed that their simultaneous increase raised A by 26%, in the bypass model. Taken together, the study potentiates engineering of cyanobacterial decarboxylation pathway in C3 plants to bypass photorespiration thereby increasing the overall efficiency of photosynthesis.

Nitrogen (N) and phosphorus (P) are two significant macronutrients for the growth and development of the plant. These two nutrients represent the highest percentage of fertilizer manufacturing and consumption in the agriculture sector. Though applied in versatility, N and P are subjected to huge losses in terms of fixation, leaching and volatilization. Nitrogen and P fertilizers have a net efficiency of 30–35%, and 18–20%, respectively. To cope with this issue, many advances have been made in terms of N sources and application methods. From split application to coating, and using nitrification inhibitors to minimize its losses, a wide range of techniques are reported. Application of organic amendments also contributes to net stabilization of N in the soil for a longer period. For coping with P losses, phosphatic fertilizers having an acidic residual effect is preferred in alkaline soil, along with indigenous P solubilization, slow-release P fertilizer modulation and use of coated fertilizers are some prominent options. Use of plant growth-promoting rhizobacteria (PGPR) to ensure sustainable N and P availability, uptake and utilization in crop plants are being advocated in this context. This chapter is an effort to comprehensively explain sources and fates of N and P in soil with special emphasis on modern ways and techniques for better management of these resources in agriculture.

Endosulfan an organochlorinated pesticide was used extensively throughout the world. Its enormous and inadequate use creates environmental as well as health problems. A bacterial strain capable to utilize endosulfan as a sole source of sulfur was isolated from pesticide contaminated soil and identified as Pseudomonas sp. on the basis of 16S rRNA. Batch experiments were conducted at various initial concentrations of endosulfan, i.e. 5, 25, 50, 75 and 100 mg/l to study its rate of degradation. After three days of incubation, 70–80% of each initial concentration was degraded by the isolated strain as compared to the control. Degradation of endosulfan increased with the time of incubation and maximum degradation was observed after 5 days of incubation. GC–MS revealed that the major metabolite was endosulfan lactone, which accumulated after 5 days of incubation. Kinetic studies at various initial concentrations also revealed that the bacterium has very promising attitude to utilize endosulfan as sole source of sulfur. It was observed that the addition of auxiliary sulfur Fe(SO4)3 in any concentration (0.05, 0.01 and 0.1%) decreased the rate of degradation of endosulfan. The ratio of μmax/ Ks was high (0.03 mg/l) when endosulfan was single sulfur source as compared to the value recorded when Fe(SO4)3 was added alongwith the endosulfan. This indicates that the newly isolated bacterium attacks sulfur moiety for its degradation.

Zinc oxide (ZnO) nanoparticles have been synthesized by co-precipitation method. The structural properties like average crystallite size, lattice parameters, volume of unit cell, and X-ray density were studied by XRD. The crystallite size was measured by using Scherrer formula. It was observed that the average crystallite size increased with the increase of annealing temperature. Morphology of the synthesized oxides was investigated by SEM. The harmful constituents like organic compounds have been removed from waste water that is toxicant. Metal oxide semiconductors had shown good photocatalytic activity to degrade harmful organics into less harmful molecules under light-illumination. In this regard the dye (Rhodamine B) was degraded with increasing exposure time of UV radiations. Almost 60% dye degradation was observed in 150 min. The ZnO was also employed as an active anti-microbial nanomaterial on the growth of C. coli. A 15 μg of ZnO nanoparticles liquefied in 1 mL of dimethyl sulfoxide revealed outstanding 95.04 ± 1.37 % inhibition activities against growth of C. coli.

Cobalt-based nanoparticles are promising candidates towards countless biomedical applications due to their unique characteristics. Co3O4 nanoparticles were synthesized by applying the sol-gel technique and finally sintered at various temperatures (700, 800, 900 °C). The crystal size, morphology, purity, and optical properties were determined using a variety of advanced characterization techniques. To investigate photodynamic therapy feasibility by using Co3O4 nanoparticles in the liver cells, in-vitro cancerous liver cells (HepG2 cells) were exposed to light of wavelength 655 nm (red light) for 30 min at 50 mW cm−2 and in dark as well. After assessment of cell viability analysis, it is concluded that light-induced photodynamic therapy shows significant phototoxic effects based on temperature dependency.

In many industries especially in automobile and aerospace, developments in near future are mainly concerned with the weight reduction to meet the global challenges of fuel economy and reduction of toxic emissions. Magnesium alloys being the lightest of all metals offer great potential to achieve that weight reduction by replacing the most commonly used materials, i.e. steel, aluminium and plastics. Magnesium alloy are being used in variety of non-structural and to some extent in semi-structural applications. However, their use in structural applications such as auto-body structure is very limited. Limited data available for high strain rate deformation of magnesium alloys combined with an insufficient understanding of the underlying deformation mechanisms adds to the reservations for their use as structural materials. For widespread usage of magnesium alloys, their dynamic behaviour must be determined to assess their performance during a crash event. In the present work, an experimental and constitutive study followed by the microstructural analysis has been carried out to investigate the dynamic behaviour of as-cast AZ91D and wrought AZ31B magnesium alloys. These alloys have been tested at strain rates in the range between 10-4s-1 and 4x103s-1 and at temperatures between -30oC and 200oC under compression and under tension between 10-4s-1 and 1500s-1 strain rates and at 25oC and at 250oC temperatures. Quasi-static tests were performed using universal testing machine and high strain tests were carried out with Hopkinson Bar apparatus. Dry ice was used to achieve below zero temperature while the elevated temperatures were obtained by using coil heater. Increasing stresses, larger strains and higher energy absorption are observed with increasing strain rate in both alloys under compression as well as in tension. On the other hand, lower stresses and relatively larger strains are observed at elevated temperatures. However, temperature has little effect on the mechanical behaviour of these alloys at dynamic strain rates. The alloys deform by dislocation glide and twining at room temperature. Number of twins decreases as the strain rate increases. Twins, voids, shear bands, grains refinement and elongation have a key role in alloys response such as strength, ductility, hardenability and energy absorption. AZ31B alloy is strongly anisotropic and shows a considerable tensile-compressive yield asymmetry. The experimental data was fit to the Johnson-Cook model and the results are in reasonable agreement except in the beginning portion of the flow curves, where the fitted curves deviate from the experimental data. DOCTOR OF PHILOSOPHY (MAE)

Aphids are agricultural pest insects that transmit viruses and cause feeding damage on a global scale. Current pest control practices involving the excessive use of synthetic insecticides over many years have resulted in aphid resistance to a number of pesticides. In nature, plants produce secondary metabolites during their interaction with insects and these metabolites can act as toxicants, antifeedants, anti-oviposition agents and deterrents towards the insects. In a previous study, we demonstrated that the butanol fraction from a crude methanolic extract of an important plant species, Isodon rugosus showed strong insecticidal activity against the pea aphid, Acyrthosiphon pisum. To further explore this finding, the current study aimed to exploit a bioactivity-guided strategy to isolate and identify the active compound in the butanol fraction of I. rugosus. As such, reversed-phase flash chromatography, acidic extraction and different spectroscopic techniques were used to isolate and identify the new compound, rosmarinic acid, as the bioactive compound in I. rugosus. Insecticidal potential of rosmarinic acid against A. pisum was evaluated using standard protocols and the data obtained was analyzed using qualitative and quantitative statistical approaches. Considering that a very low concentration of this compound (LC90 = 5.4 ppm) causes significant mortality in A. pisum within 24 h, rosmarinic acid could be exploited as a potent insecticide against this important pest insect. Furthermore, I. rugosus is already used for medicinal purposes and rosmarinic acid is known to reduce genotoxic effects induced by chemicals, hence it is expected to be safer compared to the current conventional pesticides. While this study highlights the potential of I. rugosus as a possible biopesticide source against A. pisum, it also provides the basis for further exploration and development of formulations for effective field application.

Aphids are agricultural pest insects that transmit viruses and cause feeding damage on a global scale. Current pest control involving the excessive use of synthetic insecticides over decades has led to multiple forms of aphid resistance to most classes of insecticides. In nature, plants produce secondary metabolites during their interaction with insects and these metabolites can act as toxicants, antifeedants, anti-oviposition agents and deterrents towards the insects. In a previous study, we demonstrated that the butanol fraction from a crude methanolic extract of an important plant species, Isodon rugosus showed strong insecticidal activity against the pea aphid, Acyrthosiphon pisum. It was however not known as which compound was responsible for such activity. To further explore this finding, current study aimed to exploit a bioactivity-guided strategy to isolate and identify the active compound in the butanol fraction of I. rugosus. As such, reversed-phase flash chromatography, acidic extraction and different spectroscopic techniques were used to isolate and identify the new compound, rosmarinic acid as the bioactive compound in I. rugosus. Insecticidal activity of rosmarinic acid was carried out using standard protocols on A. pisum. The data was analyzed using qualitative and quantitative statistical approaches. Considering that a very low concentration of this compound (LC90 = 5.4 ppm) causes significant mortality in A. pisum within 24 h, rosmarinic acid could be exploited as a potent insecticide against this important pest insect. Furthermore, I. rugosus is already used for medicinal purposes and rosmarinic acid is known to reduce genotoxic effects induced by chemicals, hence it is expected to be safer compared to the current conventional pesticides. While this study highlights the potential of I. rugosus as a possible biopesticide source against A. pisum, it also provides the basis for further exploration and development of formulations for effective field application.

Current work for animal manure processing is not up to the required standards and hence are not supposed to reflect the actual performance in antibiotic resistance control. As a result, this study carried out temperature-controlled aerobic composting, with sulfamethoxazole (SMX) as a typical antibiotic. The results of four different treatments demonstrated that temperature, water content, C/N ratio, EC, and pH showed no significant (p > 0.05) difference. Antibiotic resistance genes (ARGs) significantly decreased in the initial 10 days of the thermophilic phase, but the abundance of sul1 and sul2 increased greatly after 30 days. Moreover, ARGs were closely related with each other during the late stages of composting. A noteworthy effect of composting properties, especially temperature on bacterial community, which then had a positive effect on ARGs abundances. These findings provided evidence that the standard composting was still insufficient to control antibiotic resistance.

Nickel (Ni) toxicity in agricultural crops is a widespread problem while little is known about the role of biochar (BC) and other organic amendments like farm manure (FM) from cattle farm and compost (Cmp) on its alleviation. A greenhouse experiment was conducted to evaluate the effects of BC, Cmp and FM on physiological and biochemical characteristics of maize (Zea mays L.) under Ni stress. Maize was grown in Ni spiked soil without and with two rates of the amendments (equivalent to 1% and 2% organic carbon, OC) applied separately to the soil. After harvest, plant height, root length, dry weight, chlorophyll contents, gas exchange characteristics and trace elements in plants were determined. In addition, post-harvest soil characteristics like pHs, ECe and bioavailable Ni were also determined. Compared to the control, all of the amendments increased plant height, root length, shoot and root dry weight with the maximum increase in all parameters by FM (2% OC) treatment. Similarly, total chlorophyll contents and gas exchange characteristics significantly increased with the application of amendments being maximum with FM (2% OC) application. Amendments significantly increased copper, zinc, manganese and iron concentrations and decreased Ni concentrations in the plants. The highest reduction in shoot Ni concentration was recorded with FM (2% OC) followed by BC (2% OC) being 73.2% and 61.1% lower compared to the control, respectively. The maximum increase in soil pH and decrease in AB-DTPA extractable Ni was recorded with BC (2% OC) followed by FM (2% OC). It is concluded that FM (2% OC) was the most effective in reducing Ni toxicity to plants by reducing Ni uptake while BC (2% OC) was the most effective in decreasing bioavailable Ni in the soil through increasing soil pH. However, long-term field studies are needed to evaluate the effects of these amendments in reducing Ni toxicity in plants.

Transgenic potato (Solanum tuberosum L. cv. Desiree) plants expressing components of a novel cyanobacterial photorespiratory glycolate catabolism pathway were developed. Transgenic plant expressing glcD1 (glycolate dehydrogenase I) gene was referred to as synGDH and transgenic plants expressing gcl (glyoxylate carboligase) and tsr (tartronic semialdehyde reductase) genes simultaneously were designated as synGT. Both synGDH and synGT plants showed stable gene transformation, integration and expression. Enhanced glyoxylate contents in synGDH plants were detected as compared to synGT and non-transgenic (NT) plants. Phenotypic evaluation revealed that synGDH plants accumulated 11 % higher dry weight, while, tuber weight was 38 and 16 % higher than NT and synGT, respectively. Upon challenging the plants in high temperature and high light conditions synGDH plants maintained higher Fv/Fm and showed less bleaching of chlorophyll as compared to synGT and NT plants. These results indicate that genetic transformation of complete pathway in one plant holds promising outcomes in terms of biomass accumulation to meet future needs for food and energy.

Malathion, a well-known organophosphate pesticide, has been used in agriculture over the last two decades for controlling pests of economically important crops. In the present study, a single bacterium, ML-1, was isolated by soil-enrichment technique and identified as Bacillus licheniformis on the basis of the 16S rRNA technique. The bacterium was grown in carbon-free minimal salt medium (MSM) and was found to be very efficient in utilizing malathion as the sole source of carbon. Biodegradation experiments were performed in MSM without carbon source to determine the malathion degradation by the selected strain, and the residues of malathion were determined quantitatively using HPLC techniques. Bacillus licheniformis showed very promising results and efficiently consumed malathion as the sole carbon source via malathion carboxylesterase (MCE), and about 78% malathion was degraded within 5 days. The carboxylesterase activity was determined by using crude extract while using malathion as substrate, and the residues were determined by HPLC. It has been found that the MCE hydrolyzed 87% malathion within 96 h of incubation. Characterization of crude MCE revealed that the enzyme is robust in nature in terms of organic solvents, as it was found to be stable in various concentrations of ethanol and acetonitrile. Similarly, and it can work in a wide pH and temperature range. The results of this study highlighted the potential of Bacillus licheniformis strain ML-1 as a biodegrader that can be used for the bioremediation of malathion-contaminated soil.

Drought stress causes lower crop production globally. Plants have acquired many adaptations to overcome drought stress. Mungbean (Vigna radiata (L.) R.Wilczek) is a legume crop widely cultivated in South, East and Southeast Asia. It is grown in high-temperature areas where drought is the main cause of reduced plant growth and productivity. Plants cope with drought stress by activating different signalling mechanisms. The sucrose non-fermenting-1-related protein kinase 2 family (SnRK2s) is known to play vital roles in osmotic stress and in abscisic acid (ABA) signalling pathways by phosphorylating downstream targets. The genes encoding SnRK2s in mungbean and their detailed characterisation remain unexplored. We have conducted extensive genome-wide analysis for gene prediction, in silico gene analysis, evolutionary analysis and gene-expression profiling under drought-stress conditions by quantitative real-time PCR. Through genome-wide analysis, eight SnRK2 genes were predicted in the mungbean genome and were assigned the names VrSnRK2.1–VrSnRK2.8, according to their order on the chromosomes. The VrSnRK2 genes identified were classified into three clusters based on their phylogenetic relationship with those of Arabidopsis thaliana. Drought stress was imposed on 11-day-old mungbean plants by completely withholding water for 3 days. According to real-time qPCR data, the expression of most of the VrSnRK2 genes was induced by drought stress, indicating their role in the drought-stress response. One of the genes, namely SnRK2.6c, showed highest expression level (12-fold) under drought stress, possibly indicating a critical role under water-deficit conditions. These data provide important information about the VrSnRK2 gene family in mungbean. The results will help in future functional characterisation of VrSnRK2 genes.

Rare earth oxide nanoparticles (REONPs) have a high privilege in agriculture due to their unique properties as compared to their bulk counterparts. The most important REONPs include scandium, cerium, and other lanthanides, which are frequently used as fertilizer additives in many countries. Several approaches are being adopted for the commercial synthesis of REONPs. The available literature presents contradictory reviews about their beneficial effects on living organisms. Beneficial or harmful effects on plant growth are mainly dependent on the concentration of REONPs and species of plant. Bioavailability and mobility of REONPs in soil is a pH-dependent process and is also affected by their interaction with anionic ligands because of the higher oxidation state of REONPs. Plants can uptake REONPs from the soil and distribute them to aerial parts including edible organs. Accumulation of REONPs within various plant parts exhibits the potential to initiate seed emergence, escalate root and shoot growth, enhance plant growth by increasing the availability of mineral nutrients, stimulate photosynthetic processes, support plants to cope with environmental stresses by acting as a scavenger of free radicles including oxygen species, start oxidase activity, initiate antioxidant systems, and modify the enzyme activation process. Along with all these blessings there are still controversies regarding their effects on plants. This chapter is helpful for answering all ambiguous questions related to the unique characteristics of REONPs, their uptake mechanism, their interaction with soil organic and inorganic components, and their impacts on plant growth. This discussion also elucidates the phytotoxicity of REONPs in plants and their potential to accumulate in plants. This discussion helps to explore new horizons for the beneficial use of REONPs to maximize plant growth and yield on a sustainable basis along with the quality of the produce.

In this study, impact of silicon (Si) application on wheat performance under drought stress is studied. Experimental soil was sandy clay loam with an average pH of 8.01, electrical conductivity (EC) of 2.36 dSm−1, and calcium carbonate (CaCO3) content of 2.16%. Soil was severely deficient in organic matter (

Urbanization and industrialization have resulted in contamination of soils with heavy metals and other pollutants. Nickel (Ni) is one of the toxic metals, which adversely affect plant growth by altering different physiological and metabolic processes. Mineral nutrients can reduce toxic effects of Ni on physiological and metabolic functions of plants, thus improving plant growth. The role of calcium (Ca) to alleviate Ni toxicity in rice was investigated. Rice plants were grown with Ni (20 and 40 mg kg−1) and Ca (80 and 160 mg kg−1) in different combinations and without Ni and Ca as a control. Nickel (40 mg kg−1) significantly decreased shoot (54%) and root dry weights (54%), chlorophyll content (57%), the photosynthetic rate (two-fold), transpiration rate (34%) and stomatal conductance (39%) compared to control. Application of Ni (40 mg kg−1) increased the Ni concentration in shoots 22-fold and in roots 11-fold compared to control. Application of Ca (160 mg kg−1) reduced the adverse effects of Ni and the studied parameters improved to the maximum values compared to control. Calcium decreased the translocation of Ni towards the shoots that was evident from a lower translocation factor (42%) for the plants supplied with Ca compared to those grown without Ca (62%). The phytotoxicity induced by Ni on different growth and physiological parameters was alleviated by Ca as indicated by the minimum values of the phytotoxicity index for Ca fed plants (0) compared to those without Ca (2.6).

WOS: 000411432200007, Continuous irrigation of soils with untreated effluents can result in the accumulation and translocation of some metals in the soils and plants. Application of farmyard manure (FYM) to such soils may increase or decrease their availability and retention time. Calcareous soils contaminated with 100, 200, and 400mg kg(-1) Ni, Zn, and Pb as chloride salts were used, and farmyard manure added (40g kg(-1) for 90 days) with moisture contents at field capacity. Soil samples were drawn at 30 day intervals, and metals extracted with (AB-DTPA) C14H23NO3O10. With FYM application of 400 mg kg(-1), Ni availability increased from 179 (day 30) to 240 mg kg(-1) (day 90); Zn from 163 (day 30) to 230 mg kg(-1) (day 90), but, Pb decreased from 214 to 161 mg kg(-1). FYM forms multi-dentate complex which greatly enhances the Ni and Zn solubility, and organic matter immobilizes Pb in the soil.

The current study investigated the bioaccumulation potential of Petroselinum crispum (Parsley) for lead (Pb) contaminated soils. Different concentrations of lead nitrate (0, 200, 600, 1,000 and 1,200 mg kg−1 soil) were applied to the soil, and Parsley plants were grown in contaminated soil for a period of 3 months. One set of treatments was supplemented with EDTA as chelating agent to enhance the Pb uptake. The growth parameters, phytotoxic effects and Pb accumulation in different parts of experimental plants were recorded. Increasing Pb concentrations in soil caused delay in germination rate, decrease in plant height, root length and fresh and dry weight. The Pb accumulation in roots, shoots and seeds of treated plants linearly increased with Pb concentration in soil. For the highest treatment, Pb accumulation in roots and leaves was recorded to be 641 and 439.5 mg kg−1 dry weight (DW) over 20.5 and 17.25 mg kg−1 DW of control plants, respectively. At higher Pb treatment, the addition of 10 mmol EDTA had a significant effect on Pb accumulation in plants. Although Parsley seems to be a promising candidate to reclaim Pb-contaminated sites, being edible plant dietary toxicity of the plant needs to be seriously considered.

We compared acetic, ascorbic, and oxalic acids with ethylenediaminetetraacetic acid (EDTA) to enhance phytoextraction of nickel (Ni), manganese (Mn), zinc (Zn), copper (Cu), cadmium (Cd), and lead (Pb) by maize. Except ascorbic acid, acids significantly (P < 0.05) decreased shoot dry weight with maximum (5.60 g pot−1) recorded with ascorbic acid and minimum with oxalic acid (4.06 g pot−1). Maximum ammonium bicarbonate–diethylenetriaminepenta acetic acid (AB-DTPA)–extractable nickel (19.94 mg kg−1) was recorded with EDTA and it was minimum (10.57 mg kg−1) with oxalic acid. The EDTA significantly (P < 0.05) increased AB-DTPA-extractable lead while other acids decreased it. Except acetic acid, other acids significantly (P < 0.05) increased Ni and Zn concentration in shoots with maximum Ni (9.22 mg kg−1) and Zn (37.40 mg kg−1) with EDTA.

Magnesium alloys have been in use for a variety of applications in automotive and aerospace industries. However, their structural use is quite limited. In the current study, AZ31B alloy was tested and analysed at several strain rates between 10−4 s−1 and 3500 s−1. The alloy exhibited 30% (transverse direction) and 55% (rolling direction) increase in the failure strain at 3500 s−1 as compared to 10−4 s−1. Energy absorption is 2–3 times (varies in different loading directions) higher at 3500 s−1 than what is observed at 10 s. Microscopic analysis revealed that the alloy deforms by slip and twining. Twining seems to be an influential participant in the deformation in rolling direction. In 45° and normal loadings, slip is the main deformation mechanism. The Johnson–Cook model was fit to the experimental data and the results are in reasonable agreement with the experimental data except in the beginning portion of the flow curves.

Aphids are agricultural pest insects that transmit viruses and cause feeding damage on a global scale. Current pest control practices involving the excessive use of synthetic insecticides over many years have resulted in aphid resistance to a number of pesticides. In nature, plants produce secondary metabolites during their interaction with insects and these metabolites can act as toxicants, antifeedants, anti-oviposition agents and deterrents towards the insects. In a previous study, we demonstrated that the butanol fraction from a crude methanolic extract of an important plant species, Isodon rugosus showed strong insecticidal activity against the pea aphid, Acyrthosiphon pisum. To further explore this finding, the current study aimed to exploit a bioactivity-guided strategy to isolate and identify the active compound in the butanol fraction of I. rugosus. As such, reversed-phase flash chromatography, acidic extraction and different spectroscopic techniques were used to isolate and identify the new compound, rosmarinic acid, as the bioactive compound in I. rugosus. Insecticidal potential of rosmarinic acid against A. pisum was evaluated using standard protocols and the data obtained was analyzed using qualitative and quantitative statistical approaches. Considering that a very low concentration of this compound (LC90 = 5.4 ppm) causes significant mortality in A. pisum within 24 h, rosmarinic acid could be exploited as a potent insecticide against this important pest insect. Furthermore, I. rugosus is already used for medicinal purposes and rosmarinic acid is known to reduce genotoxic effects induced by chemicals, hence it is expected to be safer compared to the current conventional pesticides. While this study highlights the potential of I. rugosus as a possible biopesticide source against A. pisum, it also provides the basis for further exploration and development of formulations for effective field application.

Lightweight materials are getting more and more attraction towards their use in automobiles, planes, protective structures, electronics and supports for numerous benefits ranging from reduction in fuel consumption in vehicles to lighter and stronger in protective structures. For efficient use of materials in applications where they are subjected to unusual higher sudden loads and varying temperatures, it is necessary to know their accurate response under such conditions. Magnesium alloys due to low density, high specific strength, high specific stiffness and damping capacity have been in use for variety of structural and non-structural applications mainly in automotive and aerospace industries along with many other applications in defense, supports and electronics. In present study, the effect of temperature variation has been investigated for magnesium alloy AZ91D at high strain rates. The temperature is varied in the range between -30oC to 200oC at a strain rate of 103 s-1. Lower stresses and larger strains to peak compressive stresses are observed with increasing temperature. At higher strain rate, the effect of temperature on the alloy’s hardening behaviour is less significant

The simple sequence repeats (SSRs) are short tandem arrayed sequence motifs consisting of 2–6 bp, which are not only involved in causing human fatal diseases but also have various applications in plant genetic studies. Thanks to the advancements made in sequencing technology, now we can easily generate genomic/transcriptomic sequences in a shorter period of time. Therefore, trend to identify SSR markers needs up gradation to handle these high-throughput data. Unfortunately, existing web programs for identifying SSR markers are useful but they are unable to process high-throughput data. To overcome this disadvantage, we have constructed a web-based tool, RISA (http://sol.kribb.re.kr/RISA/), with a goal of one-click service to identify SSR markers from high-throughput data (up to 200 Mbp). RISA controls automatic input and output pipeline by demon which combines the SSR classification and investigation by Robert Kofler (SciRoKo) to search SSRs and Primer3 to identify primers specific to SSRs simultaneously. In our test, 45,495 qualified primer sets specific to 47,070 SSRs were identified by RISA from whole Arabidopsis lyrata genome (about 207 Mbp) in 15 minutes. In results, it includes SSR statistics generated from user’s queries and SSR markers information along with primers suitable for their amplification. To support handling of large amount of results, RISA provides various filtering options such as motif length, repeat units, total length and PCR product size. Therefore, we propose that RISA minimizes labour-intensive works or any other considerations which can be required during the development of SSR markers without having deep understanding of computer system and/or algorithms.

Industrialization has caused huge changes in the global budget of critical chemicals at the earth’s surface. Waste water is being added to the soil with or without treatment, causing accumulation of metals, salts, pathogens, toxins etc. in the soil. Accumulation of these substances in soil ultimately affects crop growth and human health. Metals, salts, pathogens are added into soils through various means like pesticides, fertilizer, waste water and municipal waste either remain in the soil by forming insoluble complexes with soil constituents or taken up by plants and/or may pass into drainage water. The waste water contains toxic material likely to affect plants and human health. For Agricultural irrigation may result sail salinity, sodicity and heavy metal accumulation. The untreated waste water coming from various sources contains nutrients and excess of these nutrients resulting eutrophication. However, the waste water might also bring benefits for agricultural crops as it contains organic matter and essential nutrients. The common processes which have been used to remove non-biodegradable pollutants from waste water are sedimentation, flocculation, membrane filtration, photo catalysis and use of different sorbent materials. The present chapter will provide general understanding about the different sources of waste water, its composition and impacts on soil and plant health.

Plants are frequently exposed to a plethora of environmental stresses. Being sessile creatures, they have to tolerate any stresses by altering their metabolism. To achieve tolerance, plants synthesize compatible compounds such as glycine betaine (GB). Continuous research over the years has increased our understanding about the mechanisms of stress protection by GB, which range from an osmolyte to a chaperone and from maintenance of reactive oxygen species to gene expression inducer. Various crop plants have also been transformed to synthesize GB along with model plants by introducing bacterial or plant genes. The GB-synthesizing crop plants exhibit enhanced tolerance to various abiotic stresses and out-yield wild-type plants in stressful conditions. GB has also been utilized to improve enhanced stress tolerance by utilizing it in gene stacking experiments due to its synergistic and stabilizing effects. It is reviewed here (along with comparative analysis of GB synthesis pathways and its mechanism to improve tolerance) showing that gene stacking by using GB as one component provides substantial protection. This synergistic role of GB leads us to hypothesize that it can be utilized in virtually any kind of gene stacking experiments to develop crop plants to be grown in arable and marginal lands for better tolerance to ever-changing environmental conditions and to ensure food security in underdeveloped regions of the world.

Laser ablation propulsion is a form of beam-powered propulsion in which a pulsed laser ablates a target material thus producing thrust. We report in this work the measurements of various parameters related to laser-induced micropropulsion in toluene diisocyanate-based polyurethane polymer, aluminum and Co–Ni ferrite. The targets were irradiated by a Q-switched pulsed Nd–YAG laser at 1064 nm (pulse duration 5 ns) under atmospheric conditions. A contact-free optical triangulation method was used to measure the laser ablation induced thrust in the samples. The measurements and calculations depict that Co–Ni ferrite is better in terms of critical propulsion parameters C m and I sp. It has been observed that the propulsion parameters depend on the energy per pulse of the incident laser beam.

Irrigation with untreated effluent in periurban agriculture could result in accumulation and bioconcentrations of cadmium (Cd) and lead (Pb). Different amendments were used to investigate their effect on availability, concentration, and uptake of metals by wheat in texturally different soils. Crop was irrigated with water containing Cd and Pb at 20 mg L−1, thereby adding 260 mg pot−1 of each metal. Amendments included calcium carbonate at 6 or 12%, gypsum at 50 or 100% of the soil gypsum requirement, farm manure at 7.50 or 15.00 g kg−1 soil, and a control. Amendments decreased ammonium bicarbonate diethylenetriaminepentaacetic acid (AB-DTPA)–extractable Cd and Pb concentrations and uptake by wheat. Dry matter, concentration, uptake, and extractability of Cd and Pb were greater in sandy loam soil compared with those in sandy clay loam soil irrespective of amendments. Sequential extraction showed that more metals were extracted from the control in all fractions and that predominantly metals were found in th...

There is a fast moving trend towards using lightweight materials in automotive, aerospace, building and construction, body armour and protection, sports and leisure goods. The dynamic industrial development puts higher demands for lighter and yet stronger materials. Magnesium alloys potentially met the present demands for lighter and reliable construction. With comparable specific stiffness, higher specific strength and energy absorption magnesium alloys have the potential to replace steel and aluminum alloys. Magnesium alloys are very useful for applications where materials are subjected to variable or dynamic loads such as crash events in vehicles and planes, buildings and structures against projectiles penetration etc. To know the materials’ response to impacts and their resistance to blast and shock, it is necessary to understand their behaviour under static as well as dynamic conditions. In current study, magnesium alloys AZ91D and AM50 have been studied at dynamic loading conditions and compared with aluminum alloy AA6061-T6. With significant mass saving, higher specific properties and higher energy absorption under dynamic loadings, magnesium alloys are promising candidates to replace conventional materials not only aluminum but steel as well in structural applications.

The present study reports the potential of Arundo donax for phytoextraction of arsenic from synthetic wastewater. A. donax plants were grown under greenhouse conditions in pots containing a nutrient solution amended with increasing doses of As (0, 50, 100, 300, 600 and 1000 microg L(-1)) for 21 days in a completely randomized design. Shoot and roots dry matter production, growth parameters, arsenic and nutrient tissue concentrations were measured at the end of the experiment. Increasing As concentration in nutrient solution caused an increase in shoot and root biomass without toxicity symptoms in A. donax growing under a range of As concentration from 50 to 600 microg L(-1). Elevated oxidative stress was observed at As supplied level of 1000 microg L(-1). The As doses up to 600 microg L(-1) did not affect the growth of A. donax. It is suggested that A. donax plants may be employed to treat contaminated waters containing arsenic concentrations up to 600 microg L(-1).

Automotive and aerospace manufacturers are looking for ways to reduce the gross weight of vehicles to economize on fuel consumption as well as improve performance. Magnesium alloys, being the lightest among the metals, are highly attractive as potential structural materials. However, their use is quite limited, especially in structural applications. As of this writing, knowledge of the dynamic behavior of magnesium alloys is not sufficient to depict their true response under dynamic loadings, and has been a hindrance to their widespread use. In this research, an experimental study, followed by constitutive and microstructural analyses, was carried out to investigate the behavior of AZ31B magnesium alloy. The alloy has been tested at strain rates in the range between 10−4 s−1 and 1.5×103 s−1 under tension.

Although industrialization and high input agriculture has led to improvements in standards of human life on earth, it has resulted in multifarious problems for all inhabitants of this blue planet. Among many others, enrichment of water–soil–plant ecosystem with potentially toxic elements is considered to be one of the most serious threats due to ill effects over all living organisms including humans. As compared to other toxic elements, soil contamination due to Pb warrants special attention because of its long retention in soil and lethal effects on crop growth and human health. A number of techniques have been developed and devised to lower the total and / or available Pb concentration in soils and in turn their accumulation the food chain. However, phytoextraction has attracted tremendous attention from the scientific community due to its lower cost, less disruptive effects on soil and the surrounding environment, and wider acceptance in society. The total concentration of Pb in contaminated soils may not be truly representative of its bioavailability because the major portions of Pb in soil occur in the unavailable forms. Therefore, certain types of chemicals are applied to soil to increase the mobility and phytoavailabilty of Pb to help improve phytoremediative ability of plants to clean up soil within a reasonable time frame. Synthetic and natural organic ligands, such as EDTA, ethylene diamine disuccinate (EDDS), low-molecular-weight organic acids (LMWOA), nitrilotriacetic acid (NTA) and humic substances (HSs) have been used extensively in Pb remediation techniques. With increasing use of synthetic chelants for remediation techniques, detailed understanding of key factors and mechanisms behind this technology is needed before its application on a commercial basis. The present manuscript, therefore, highlights the role of synthetic chelators in the remediation of Pb contaminated soils and also critically assesses the risks and limitations associated with this technology.

Lighter yet stronger magnesium alloys have become very attractive for applications where materials undergo larger strains such as crash events in vehicles and planes, penetration of projectiles in personal body armour and vehicle armours. Excellent combination of light weight and good mechanical properties put magnesium alloys ahead of other structural materials in applications where high specific properties are required. It is well anticipated that magnesium alloys have enormous potential as a whole or a part of protective structures.

Phosphorus (P) deficiency is a common nutritional factor limiting agricultural production around the globe. Application of phosphatic fertilizers is generally recommended to cope with P deficiency; however, low use efficiency of available P fertilizers both in calcareous and acid soils limits its viability and also had serious environmental concerns. Higher plants have adapted a number of mechanism to live with low available P in soil such as changes in root morphology and architecture, decreased growth rate, improved P uptake and utilization efficiency, and exudation of organic acids and enzymes to solubilize external inorganic and organic P compounds in the rhizosphere. Plant species and even cultivars widely differ in P efficiency because of differences in one or more of these mechanisms. Exploitation of these genetic variations among crop plants can sustain agricultural production. Understanding the mechanism involved in sensing P deficiency could facilitate selection, breeding, and genetic engineering approaches to improve crop production in P-stressed environments and could reduce dependence on nonrenewable inorganic P resources. In this chapter, we briefly reviewed the responses of P deficiency in higher plants, their adaptive mechanisms, and signaling pathways.

Reactive oxygen species (ROS) are produced naturally in plants during normal growth conditions. However, their production is accelerated manifold during various abiotic and biotic stresses. Rapid and efficient detoxification of ROS is vital to avoid any damage at cellular level. This is done by a well defined antioxidative system which comprises of various enzymes (superoxide dismutase, catalases and peroxidases) and low molecular weight compounds such as; praline, betaine, ascorbate and glutathione. Among these, ascorbate and glutathione are directly involved in scavenging of ROS. The present article will emphasize on the biosynthesis and role of ascorbate and glutathione during oxidative stress.

The dynamic stress–strain characteristics of magnesium alloys have not been sufficiently studied experimentally. Thus, the present work investigated compressive dynamic stress–strain characteristics of two representative magnesium alloys: AZ91D and AZ31B at high strain rates and elevated temperatures. In order to use the stress–strain characteristics in numerical simulations to predict the impact response of components, the stress–strain characteristics must be modeled. The most common approach is to use accepted constitutive laws. The results from the experimental study of the response of magnesium alloys AZ91D and AZ31B under dynamic compressive loading, at different strain rates and elevated temperatures are presented here. Johnson–Cook model was used to best fit the experimental data. The material parameters required by the model were obtained and the resultant stress–strain curves of the two alloys for each testing condition were plotted. It is found that the dynamic stress–strain relationship of both magnesium alloys are strain rate and temperature dependent and can be described reasonably well at high strain rates and room temperature by Johnson–Cook model except at very low strains. This might be due to the fact that the strain rate is not strictly constant in the early stage of deformation.