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Lanthanum (La), the second most abundant rare earth element (REE) is emerging as an environmental issue, with the potential to impact ecosystems and human health. Major sources of soil contamination by La include agricultural, and industrial activities. Lanthanum is non-essential for plant growth but accumulates in various plant parts. The uptake of La by plants is intricately influenced by various factors such as soil pH, redox potential, cation exchange capacity, presence of organic acids and rhizosphere composition. These factors significantly impact the availability and absorption of La ions. Lanthanum impact on plants depends on soil characteristics, cultivated species, developmental stage, La concentration, treatment period, and growth conditions. Excessive La concentrations affect cell division, DNA structure, nutrient uptake, and photosynthesis and induce toxicity symptoms. Plants employ detoxification mechanisms like vacuolar sequestration, osmolyte synthesis, and antioxidant defense system. However, higher concentrations of La can overwhelm these defense mechanisms, leading to adverse effects on plant growth and development. Further, accumulation of La in plants increases the risk for human exposure. Strategies to mitigate La toxicity are, therefore, vital for ecosystem protection. The application of phytoremediation, supplementation, chelation, amendments, and biosorption techniques contributes to the mitigation of La toxicity. This review provides insights into La sources, uptake, toxicity, and alleviation strategies in plants. Identifying research gaps and discussing advancements aims to foster a holistic understanding and develop effective strategies for protecting plant health and ecosystem resilience against La contamination., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In the fast-evolving realm of communication technology, microstrip patch antennas (MPAs) are in high demand owing to their compact size, lightweight, inexpensive, ease of integration, and compatibility with modern electronic devices. This research focuses on the synthesis of ZnAl 2 O 4 Ca (ZAC) ceramic nanoparticles using an economical sol-gel method suitable for microstrip patch antenna applications. The structural analysis study of ZAC nanoparticles confirmed the polycrystalline nature with 8.1 nm of crystallite size whereas an investigation of functional groups showed the corresponding vibration modes. Morphological investigation revealed the spherical grains having their mean diameter of 12.32 nm. The dielectric property's examination, revealed the dielectric permittivity of 13, loss tangent of 0.02, and conductivity of 67 μΩ -1  cm -1 . Furthermore, a prototype patch antenna fabricated using ZAC ceramics demonstrated a dual-band performance at frequencies 2.8 GHz and 4.8 GHz, with return losses of - 25.78 dB and - 28.5 dB, respectively. This work suggests the suitability of ZAC ceramic nanoparticles for use in WLAN applications., (© 2024. The Author(s).)

Soil salinization significantly affects crop production by reducing crop quality and decreasing yields. Climate change can intensify salinity-related challenges, making the task of achieving global food security more complex. To address the problem of elevated salinity stress in crops, nanoparticles (NPs) have emerged as a promising solution. NPs, characterized by their small size and extensive surface area, exhibit remarkable functionality and reactivity. Various types of NPs, including metal and metal oxide NPs, carbon-based NPs, polymer-based NPs, and modified NPs, have displayed potential for mitigating salinity stress in plants. However, the effectiveness of NPs application in alleviating plant stress is dependent upon multiple factors, such as NPs size, exposure duration, plant species, particle composition, and prevailing environmental conditions. Moreover, alterations to NPs surfaces through functionalization and coating also play a role in influencing plant tolerance to salinity stress. NPs can influence cellular processes by impacting signal transduction and gene expression. They counteract reactive oxygen species (ROS), regulate the water balance, enhance photosynthesis and nutrient uptake and promote plant growth and yield. The objective of this review is to discuss the positive impacts of diverse NPs on alleviating salinity stress within plants. The intricate mechanisms through which NPs accomplish this mitigation are also discussed. Furthermore, this review addresses existing research gaps, recent breakthroughs, and prospective avenues for utilizing NPs to combat salinity stress., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Mine tailings are the discarded materials resulting from mining processes after minerals have been extracted. They consist of leftover mineral fragments, excavated land masses, and disrupted ecosystems. The uncontrolled handling or discharge of tailings from abandoned mine lands (AMLs) poses a threat to the surrounding environment. Numerous untreated mine tailings have been abandoned globally, necessitating immediate reclamation and restoration efforts. The limited feasibility of conventional reclamation methods, such as cost and acceptability, presents challenges in reclaiming tailings around AMLs. This study focuses on phytorestoration as a sustainable method for treating mine tailings. Phytorestoration utilizes existing native plants on the mine sites while applying advanced principles of environmental biotechnology. These approaches can remediate toxic elements and simultaneously improve soil quality. The current study provides a global overview of phytorestoration methods, emphasizing the specifics of mine tailings and the research on native plant species to enhance restoration ecosystem services., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Cadmium (Cd) is a highly toxic heavy metal that adversely affects humans, animals, and plants, even at low concentrations. It is widely distributed and has both natural and anthropogenic sources. Plants readily absorb and distribute Cd in different parts. It may subsequently enter the food chain posing a risk to human health as it is known to be carcinogenic. Cd has a long half-life, resulting in its persistence in plants and animals. Cd toxicity disrupts crucial physiological and biochemical processes in plants, including reactive oxygen species (ROS) homeostasis, enzyme activities, photosynthesis, and nutrient uptake, leading to stunted growth and reduced biomass. Although plants have developed defense mechanisms to mitigate these damages, they are often inadequate to combat high Cd concentrations, resulting in yield losses. Nanoparticles (NPs), typically smaller than 100 nm, possess unique properties such as a large surface area and small size, making them highly reactive compared to their larger counterparts. NPs from diverse sources have shown potential for various agricultural applications, including their use as fertilizers, pesticides, and stress alleviators. Recently, NPs have emerged as a promising strategy to mitigate heavy metal stress, including Cd toxicity. They offer advantages, such as efficient absorption by crop plants, the reduction of Cd uptake, and the enhancement of mineral nutrition, antioxidant defenses, photosynthetic parameters, anatomical structure, and agronomic traits in Cd-stressed plants. The complex interaction of NPs with calcium ions (Ca 2+ ), intracellular ROS, nitric oxide (NO), and phytohormones likely plays a significant role in alleviating Cd stress. This review aims to explore the positive impacts of diverse NPs in reducing Cd accumulation and toxicity while investigating their underlying mechanisms of action. Additionally, it discusses research gaps, recent advancements, and future prospects of utilizing NPs to alleviate Cd-induced stress, ultimately promoting improved plant growth and yield., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Miniaturization of microstrip patch antennas (MPAs) is vital in applications such as wireless networks, mobile devices, global positioning satellites, and upcoming wireless terminals. This miniaturization has led to a demand for new materials with higher permittivity compared to the existing ones. Zinc aluminate (ZnAl 2 O 4 ) ceramic is an exceptional and versatile material in this context, thanks to its high dielectric permittivity and low tangent loss, making it suitable for microwave applications. This article explores the feasibility of sol-gel-prepared Ca-doped ZnAl 2 O 4 ceramic nanoparticles to be useful in fabricating a MPA. These nanoparticles were examined using X-ray diffraction, which confirmed their polycrystalline structure, and the morphological investigation evidenced the spherical grains having a mean diameter of 16 nm. The dielectric permittivity of the ZnAl 2 O 4 Ca nanoparticles is 21.11, with a tangential loss of 0.0247. A prototype MPA made by using Ca-doped ZnAl 2 O 4 nanoparticles showed a return loss of -20.92 dB at a resonance frequency of 6.8 GHz with a bandwidth of 600 MHz. These results indicate that Ca-doped ZnAl 2 O 4 ceramic nanoparticles possess exceptional dielectric characteristics, which make them a promising candidate for MPA applications., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Methanol is noxious to insect pests, but most plants do not make enough of it to shield themselves from encroaching insects. Methanol emission is known to increase in the instance of herbivory. In the current study, we showed that Aspergillus niger pectin methylesterase over-expression increases methanol emission and confers resistance to polyphagous insect pests on transgenic cotton plants by impeding the possible methanol detoxification pathways. Transgenic plants emitted ∼11 fold higher methanol displaying insect mortality of 96% and 93% in Helicoverpa armigera and Spodoptera litura, respectively. The larvae were unable to survive and finish their life cycle and the surviving larvae exhibited severe growth retardation. Insects try to detoxify methanol via catalase, carboxylesterase and cytochrome P450 monooxygenase enzymes, amongst which cytochrome P450 plays a major role in oxidizing methanol to formaldehyde and formaldehyde to formic acid, which is broken down into carbon dioxide and water. In our study, catalase and esterase enzymes were found to be upregulated, but cytochrome P450 monooxygenase levels were not much affected. Leaf disc assays and In-planta bioassays also showed 50-60% population reduction in the sap sucking pests, such as Bemisia tabaci and Phenacoccus solenopsis. These findings imply that elevated methanol emissions confer resistance in plants against chewing and sap-sucking pests by tampering the methanol detoxification pathways. Such mechanism will be useful in imparting expansive resistance against pests in plants., Competing Interests: Declaration of Competing Interest Authors declare no conflict of interest with anyone., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Chromium (Cr), one of the hazardous pollutants, exists predominantly as Cr(VI) and Cr(III) in the environment. Cr(VI) is more toxic than Cr(III) due to its high mobility and solubility. Elevated levels of Cr in agricultural soil due to various anthropogenic activities cause Cr accumulation in plants, resulting in a significant reduction in plant yield and quality due to Cr-induced physiological, biochemical and molecular alterations. It can infiltrate the food chain through crop plants and cause harmful effects in humans via biomagnification. Cr(VI) is linked to cancer in humans. Therefore, mitigation strategies are required to remediate Cr-polluted soils and limit its accumulation in plants for safe food production. Recent research on metal and metal oxide nanoparticles (NPs) has shown that they can effectively reduce Cr accumulation and phytotoxicity. The effects of these NPs are influenced by their type and dose, exposure method, plant species and experimental settings. In this review, we present an up-to-date compilation and comprehensive analysis of the existing literature regarding the process of uptake and distribution of Cr and impact and potential mechanisms of metal and metal oxide nanoparticles led mitigation of Cr-induced stress in plants. We have also discussed recent developments, existing research gaps and future research directions in the field of Cr stress mitigation by NPs in plants. Overall, this review can provide valuable insights in reducing Cr accumulation and toxicity using metal and metal oxide nanoparticles, thereby promoting safe and sustainable cultivation of food and phytostabilization of Cr-polluted soil., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Cotton is a significant industrial crop, playing an essential role in the global economy that suffers several setbacks due to biotic and abiotic adversities. Despite such problems, biotechnological advances in cotton are limited because of genetic transformation and regeneration limitations. Here, we present a detailed protocol optimized based on previously published papers, along with our modifications. These involve changes in Agrobacterium concentration, co-cultivation time and temperature, hormones used for regeneration, media manipulation for embryogenic callus production, and efficient rescue of deformed embryos. Further, this protocol has been used in genetic studies on biotic and abiotic stress in cotton. This protocol assures a reproducible stable transgenic cotton development procedure via somatic embryogenesis that can be used by researchers worldwide. This protocol was validated in: Nat Biotechnol (2016), DOI: 10.1038/nbt.3665., Competing Interests: Competing interestsThe authors declare that there are no existing conflicts of interest as to their knowledge., (Copyright © 2023 The Authors; exclusive licensee Bio-protocol LLC.)

This paper reports the sol-gel preparation of ZnAl 2 O 4 (ZA) and ZnAl 2 O 4 -TiO 2 (ZAT) dielectric ceramic nanoparticles for fabricating prototype microstrip patch antennas. The prepared nanoparticles were polycrystalline in nature with their crystallite sizes of 9.4 and 11 nm, along with average grain diameters of 16 and 12 nm corresponding to samples ZA and ZAT. Dielectric properties were investigated using an LCR meter, which endorsed enhanced dielectric permittivity and decreased dielectric loss. Finally, prototype microstrip patch antennas named AZA and AZAT were fabricated using the prepared nanoparticles, and their performances were evaluated. Both antennas exhibited resonant peaks in the frequency range from 6.4 to 6.5 GHz. The antenna AZAT showed a return loss of -37.07 dB with a voltage standing wave ratio (VSWR) of 1.02 compared to the return loss of -19.42 dB, and a VSWR of 1.24 corresponds to AZA. The AZAT antenna's improved return loss can be regarded as the increased dielectric permittivity and reduced tangent loss of the ZAT sample. Furthermore, the ZAT antenna evidenced increased/decreased forwarded/reflected power decreased reflection coefficient and an optimal VSWR value compared to that of the AZA antenna., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Zinc aluminate (ZnAl 2 O 4 ) is a well-recognized ceramic demanded in several microwave applications. Further, the addition of dielectric materials in ZnAl 2 O 4 improved its dielectric properties, which is promising for the realization of a microstrip patch antenna. This article reports the investigation of ZnAl 2 O 4 TiO 2 (ZAT) dielectric ceramic nanoparticles synthesized by the sol-gel process. The X-ray diffraction analysis revealed the crystalline nature of the prepared nanoparticles, with a tetragonal structure of anatase-, and rutile-TiO 2 phases coexisting with the cubic phase of ZnAl 2 O 4 . The estimated crystallite size of the dielectric ceramic is 13.3 nm. Transmission electron microscopy (TEM) micrographs demonstrated the spherical grains with their mean diameter of 14.75 nm, whereas the selected-area electron diffraction (SAED) pattern endorsed the crystallinity of the sample. Raman measurement revealed the vibrational modes in accordance with the TiO 2 and ZnAl 2 O 4 compounds. The dielectric properties of the ZAT sample showed the dielectric permittivity in the range of 22.12-21.63, with its minimum loss from 0.056 to 0.041. Finally, a prototype microstrip antenna was fabricated using the prepared nanoparticles, which demonstrated a return loss of - 30.72 dB at the resonant frequency of 4.85 GHz with its bandwidth of 830 MHz., (© 2022. The Author(s).)

Manganese (Mn) is an essential element for plant growth but it becomes phytotoxic at higher concentrations. The effect of Mn-excess in hydroponics medium was examined on growth, oxidative stress, and ultrastructural changes in chloroplasts and mitochondria as well proteomic alterations in rice (Oryza sativa L.) seedlings. Seedlings grown with 1 mM and 2 mM Mn in nutrient medium for 8 days showed decline in length and fresh biomass, and decline in net photosynthetic rate, transpiration rate, and stomatal conductance. Shoots of the seedlings had higher Mn content than roots. Mn-treated seedlings showed increased production of O 2 ·- , H 2 O 2 , and . OH, increased lipid peroxidation, increased carbonylation of proteins, and increased proteolytic activity compared to untreated seedlings. Mn-treated seedlings showed disorganization and swelling of chloroplasts with appearance of plastoglobuli in TEM images and deformity in shape of mitochondria. Using confocal microscopy depolarization of mitochondrial membrane was observed marked by green fluorescence of JC-1 dye monomers in Mn-treated roots. Proteomics studies from leaves of Mn-treated seedlings involving 2DE and PDQuest analysis showed differential expression of 23 proteins, among which MALDI-TOF/TOF mass spectrometry analysis revealed Mn-led downregulation of photosynthesis-related proteins, namely oxygen-evolving complex protein associated with PSII, PAP-3, enzyme involved in protein folding peptidyl-prolyl cis-trans isomerase (PPIase) and carbohydrate metabolizing enzymes hydrolase, fructose-bisphosphate aldolase, transketolase, and isocitrate dehydrogenase, whereas ATP-dependent Clp protease, peroxidase, and nucleic acid-binding proteins were downregulated due to Mn treatment. Results indicate that Mn-excess inhibits growth of rice plants with induction of oxidative stress, causing structural alterations in chloroplasts, mitochondria, inhibiting photosynthesis, and downregulating many photosynthesis and carbohydrate metabolism-related proteins.

Few works are reported on solvothermal preparation of nanoparticles by utilizing acetone alone without a surfactant. This synthesis approach is found to be prominent for producing the mesoporous structure, which is crucial in improving the dye loading of the photoanode. In addition, doping of metal ions is advantageous in order to bring down the excitation energy, which is promising for boosting the performance of the doped oxides. This research aims to synthesize various kinds of doped-TiO 2 nanocrystals to serve as photoanode materials in dye-sensitized solar cells (DSSCs). An X-ray diffraction study evidenced the existence of the crystalline phase in pure and doped-TiO 2 nanocrystals. Rietveld refinement study showed the mixed phases of crystalline TiO 2 in the CrT, CuNT, and ST as compared to a single anatase phase in the samples PT, AgT, BT, CoT, FeT, SnT, ZT, VT, and ZMT. The absorption spectroscopy analysis demonstrated the reduced optical band gap from 3.10 to 2.79 eV. Scanning electron microscopy investigation endorsed the formation of TiO 2 mesoporous microspheres with a mean diameter ranging from 200 to 331 nm along with a nanocrystal diameter ranging from 10 to 20 nm. Doping with the different dopants enhanced the conversion efficiency of DSSCs from 1.31 to ∼6%. Furthermore, we have performed the electrochemical impedance spectroscopy of DSSCs, and the findings are presented., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Dielectric reflectors are the passive components that have their potential demands for various purposes, such as back-end reflector in solar cells, the band pass filters in optical instruments, thermal reflector and so on. Though well-established techniques for manufacturing such reflectors are available, the demand for their low-cost production with a minimum number of coatings has attracted the attention of the scientific community. In this framework, this paper addresses the process optimization for the low-cost and rapid fabrication of dielectric TiO 2 /SiO 2 reflectors with 100% reflectance. Numerous studies are carried out to explore the structural, morphological, and optical characteristics of reflectors. We summarize that the desired reflection band of a selective-wavelength range can be realized by varying the precursor and catalyst concentrations, annealing cycle, and the spin rate. With this, we noticed the shifting of reflection window from the visible (Vis) to near-infrared (NIR) wavelength region using reflectors of merely 2.5 stacks of TiO 2 /SiO 2 films. We also performed the thermal response of the reflector by radiating an infrared light source and observed an exceptional performance indicating its thermal shielding application.

Identifying the maximum level of inherent defense against harmful insects in natural variation among wild lineages of crop plants may result in high yield tolerant varieties and reducing use of chemical insecticides. However, knowledge of natural cotton genotypes with high insect-resistance is still indistinguishable at the biochemical or molecular level. In the present study, different cultivated Gossypium hirsutum varieties were evaluated for their inherent insect-tolerance against two major cottons chewing pests. The insect bio-assay identified two tolerant and one susceptible cotton varieties. The study demonstrates difference in phenolic acids, proanthocyanidin and tannin accumulation in tolerant and susceptible varieties. The post-infestation of chewing pests increases transcript level of the phenylpropanoid pathway genes were detected in tolerant varieties as compared to the susceptible varieties. Altogether, chewing pest-tolerance level in cotton varieties is the cumulative effect of enhanced phenylpropanoid pathway genes expression and secondary metabolite leading to defense responses to conventional host plant.

In the present study the potentials of aqueous extracts of the two plants, neem ( Azadirachta indica ) and Tulsi ( Ocimum sanctum ) were examined in alleviating arsenic toxicity in rice ( Oryza sativa L.) plants grown in hydroponics. Seedlings of rice grown for 8 days in nutrient solution containing 50 μM sodium arsenite showed decline in growth, reduced biomass, altered membrane permeability and increased production of superoxide anion ( O 2 ·- ), H 2 O 2 and hydroxyl radicals ( · OH). Increased lipid peroxidation marked by elevated TBARS (thiobarbituric acid reactive substances) level, increased protein carbonylation, alterated levels of ascorbate, glutathione and increased activities of enzymes SOD (superoxide dismutase), CAT (catalase), APX (ascorbate peroxidase) and GPX (glutathione peroxidase) were noted in the seedlings on As treatment. Exogenously added leaf aqueous extracts of Azadirachta indica (0.75 mg mL -1 , w/v) and Ocimum sanctum (0.87 mg mL -1 , w/v) in the growth medium considerably alleviated As toxicity effects in the seedlings, marked by reduced As uptake, restoration of membrane integrity, reduced production of ROS, lowering oxidative damage and restoring the levels of ascorbate, glutathione and activity levels of antioxidative enzymes. Arsenic uptake in the seedlings declined by 72.5% in roots and 72.8% in shoots, when A. indica extract was present in the As treatment medium whereas with O. sanctum extract, the uptake declined by 67.2% in roots and 70.01% in shoots. Results suggest that both A. indica and O. sanctum aqueous extracts have potentials to alleviate arsenic toxicity in rice plants and that A. indica can serve as better As toxicity alleviator compared to O. sanctum ., Competing Interests: Conflict of interestAuthors declare that there is no conflict of interest., (© Prof. H.S. Srivastava Foundation for Science and Society 2019.)

During travel, passengers are exposed to high concentrations of PM which constitute a significant fraction of daily personal exposures. We carried out comprehensive mobile monitoring for a distance of 400km on an Indian National Highway during the winter season to evaluate the PM 2.5 Personal Concentrations (PC) and mass exposure in three traffic microenvironments (public bus, car with AC (Car CW) and car without AC (Car OW)) and to quantify the key factors that influence it. The mean concentrations were highest inside Car OW (175.3±142.7μgm -3 ) followed by bus (134.0±113.9μgm -3 ) and lowest in Car CW (78.8±37.1μgm -3 ). PC during in-city highway sections were greater than out-city highway sections during Bus and Car OW journeys. PC were higher during morning than evening journeys in Bus and Car OW. Mean PC in different seating positions in Bus followed the trend: middle>rear>front. Results of the Linear Mixed-Effects Models (LMM) indicated that journey timings were the significant predictors of PC for Bus and Car OW. The exposures per unit time followed trend: Car OW>Bus>Car CW. Total mass of inhaled exposures however followed a different trend: Bus>Car OW>Car CW, because Bus needed longer duration to cover the entire distance. Car CW users experienced both the least PC and mass exposures. We estimated that the road repairing works contributed ~22% in Bus and Car OW, and ~12% in Car CW increment in mass exposures. These findings indicate that management of exposures needs to consider mass exposures in addition to PC, for curtailing the adverse health effects relating to long distance journeys. Highway authorities should focus on early completion of construction and repairing activities to reduce exposures to passengers., (Copyright © 2019. Published by Elsevier B.V.)

Terminalia arjuna (Ta) bark contains various natural antioxidants and has been used to protect animal cells against oxidative stress. In the present study, we have examined alleviating effects of Ta bark aqueous extract against Ni toxicity in rice (Oryza sativa L.). When rice seedlings were raised for 8 days in hydroponics in Yoshida nutrient medium containing 200 μM NiSO 4 , a decline in height, reduced biomass, increased Ni uptake, loss of root plasma membrane integrity, increase in the level of O 2 ˙ - , H 2 O 2 and ˙OH, increased lipid peroxidation, decline in photosynthetic pigments, increase in the level of antioxidative enzymes superoxide dismutase, catalase and glutathione peroxidase and alterations in their isoenzyme profile patterns were observed. Transmission electron microscopy (TEM) showed damage to chloroplasts marked by disorganised enlarged starch granules and disrupted thylakoids under Ni toxicity. Exogenously adding Ta bark extract (3.2 mg ml -1 ) to the growth medium considerably alleviated Ni toxicity in the seedlings by reducing Ni uptake, suppressing generation of reactive oxygen species, reducing lipid peroxidation, restoring level of photosynthesis pigments and ultrastructure of chloroplasts, and restoring levels of antioxidative enzymes. Results suggest that Ta bark extract considerably alleviates Ni toxicity in rice seedlings by preventing Ni uptake and reducing oxidative stress in the seedlings.

The most important objectives that are frequently found in bio-analytical chemistry involve applying tools to relevant medical/biological problems and refining these applications. Developing a reliable sample preparation step, for the medical and biological fields is another primary objective in analytical chemistry, in order to extract and isolate the analytes of interest from complex biological matrices. Since, main inborn errors of metabolism (IEM) diagnosable through uracil analysis and the therapeutic monitoring of toxic 5-fluoruracil (an important anti-cancerous drug) in dihydropyrimidine dehydrogenase deficient patients, require an ultra-sensitive, reproducible, selective, and accurate analytical techniques for their measurements. Therefore, keeping in view, the diagnostic value of uracil and 5-fluoruracil measurements, this article refines several analytical techniques involved in selective recognition and quantification of uracil and 5-fluoruracil from biological and pharmaceutical samples. The prospective study revealed that implementation of molecularly imprinted polymer as a solid-phase material for sample preparation and preconcentration of uracil and 5-fluoruracil had proven to be effective as it could obviates problems related to tedious separation techniques, owing to protein binding and drastic interferences, from the complex matrices in real samples such as blood plasma, serum samples.

Aluminum (Al) is a major constraint to crop productivity in acid soils, whereas water deficit severely limits crop production in arid and semi-arid regions of the world. The objective of the present study was to examine the effects of both stresses, Al excess and water deficit, individually and in combination on the production of the reactive oxygen species (ROS) superoxide anion (O2˙(-)), hydrogen peroxide (H2O2), hydroxyl radical, and lipid peroxidation and the activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and guaiacol peroxidase (GPX) in the seedlings of two rice (Oryza sativa L.) cvs. Malviya-36 (sensitive to water deficit and Al) and Vandana (tolerant to water deficit and Al). When 15-day grown seedlings were exposed to water deficit (created with 15% polyethylene glycol, PEG-6000) or Al (1 mM AlCl3) treatment or both treatments together for 24-72 h, the lengths and fresh weights of root/shoot declined in the seedlings of the sensitive cultivar, whereas in the tolerant seedlings, either little or insignificant decline in these parameters was observed due to the treatments. Biochemical determinations and histochemical studies revealed that under a similar level of water deficit, Al, or combined treatment, seedlings of sensitive cultivar showed a higher level of production of O2˙(-), H2O2, hydroxyl radical, and lipid peroxides compared to the tolerant seedlings. Seedlings of tolerant cultivars, both in roots and shoots, had constitutively higher activity levels of antioxidative enzymes SOD, CAT, and GPX and showed a greater increase in activity under water deficit or Al treatment alone or in combination compared to the similarly treated seedlings of sensitive cultivar. Our results suggest that a lower constitutive level of ROS and a high antioxidative enzyme capacity are associated with tolerance to both water deficit and Al excess in rice seedlings.

The present study was undertaken to examine the possible roles of calcium (Ca(2+)) and silica (Si) in protection against oxidative damage due to Cd(2+) toxicity in rice (Oryza sativa L.) seedlings grown in hydroponics. Rice seedlings raised for 12 days in hydroponics containing Cd(NO3)2 (75 μM) showed reduced growth; increase in the level of reactive oxygen species (ROS) (O2 (·-) and H2O2), thiobarbituric acid reactive substances (TBARSs) and protein carbonylation; and increase in the activity of antioxidant enzymes-superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (GPX) compared to untreated controls. Exogenously added Ca(2+) (2 mM) and Si (200 μM) significantly alleviated negative effect of Cd(2+) by restoration of growth of the seedlings, suppression of Cd(2+) uptake and restoration of root plasma membrane integrity. The levels of O2 (·-), H2O2, lipid peroxidation and protein carbonyls were much lower when Ca(2+) and Si were added in the growth medium along with Cd(2+) as compared to Cd-alone-treated seedlings. Ca(2+) and Si lowered Cd-induced increase in SOD, GPX and APX activities while they elevated Cd-induced decline in CAT activity. Using histochemical staining of O2 (·-) and H2O2 in leaf tissues, it was further confirmed that added Ca(2+) and Si suppressed Cd-induced accumulation of O2 (·-) and H2O2 in the leaves. The results suggest that exogenous application of Ca(2+) and Si appears to be advantageous for rice plants in alleviating Cd(2+) toxicity effects by reducing Cd(2+) uptake, decreasing ROS production and suppressing oxidative damage. The observations indicate that Ca(2+) and Si treatments can help in reducing Cd(2+) toxicity in rice plants.

Bipolaris sorokiniana synthesizes the 1,8-dihydroxynaphthalene (DHN) melanin via pentaketide pathway and promotes the development of aerial mycelia and conidia. A melanin biosynthesis inhibitor Tricyclazole (TCZ), brought changes when applied at 5-100 μg ml(-1) concentration in the colony morphology, radial growth, mycelia weight, melanin content, antioxidant enzymes (SOD and CAT) and extracellular hydrolytic enzymes (cellulase, pectinase, amylase and protease) in black, mixed and white isolates of B. sorokiniana. A significant alteration was recorded in antioxidant enzymes in black and mixed isolates; however, non-significant alteration was recorded in white isolate. Isolates of B. sorokiniana exposed to 100 µg ml(-1) TCZ showed significantly increased formation of superoxide radical (O 2 (·-) ) and hydrogen peroxide (H2O2)·H2O2 was detected significantly high in hyphae and conidia while, O 2 (·-) was found primarily in the conidia. Microscopic results suggest that TCZ damages not only the cell wall but also the cell membrane. The foliar application of TCZ (25, 50 and 100 µg ml(-1)) decreases the area under disease progress curve, lesion development and spore formation on barley leaves thereby reducing potential for the disease development. In conclusion TCZ influences the pathogenic ability by damaging the cell structure of hyphae and conidia and also alters the antioxidant enzyme levels in B. sorokiniana. TCZ may therefore, works against to pathogen for better management of spot blotch disease in barley infected with B. sorokiniana.

Adverse environmental conditions including heavy metal stress impose severe effects on the plant growth and development limiting productivity and yield. Studies demonstrated that changes in genome-wide expression modulate various biochemical processes and molecular components in response to heavy metal stress in plants. Some of the key components involved in such a regulation are the transcription initiation machinery, nucleotide sequence of promoters and presence of cis-acting elements. Therefore, identification of the putative cis-acting DNA sequences involved in gene regulation and functional characterization of promoters are important steps in understanding response of plants to heavy metal stress. In this study, comprehensive analysis of the proximal promoters of members of rice sulfate transporter gene family which is an essential component of stress response has been carried out. Analysis suggests presence of various common stress related cis-acting elements in the promoters of members of this gene family. In addition, transcriptional regulation of the arsenic-responsive high affinity sulfate transporter, OsSul1;1, has been studied through development of Arabidopsis transgenic lines expressing reporter gene encoding β-glucuronidase under the control of OsSul1;1 promoter. Analysis of the transgenic lines suggests differential response of the OsSul1;1 promoter to various heavy metals as well as other abiotic stresses.

Arsenic (As), a naturally occurring metallic element, is a dreadful health hazard to millions of people across the globe. Arsenic is present in low amount in the environment and originates from anthropogenic impact and geogenic sources. The presence of As in groundwater used for irrigation is a worldwide problem as it affects crop productivity, accumulates to different tissues and contaminates food chain. The consumption of As contaminated water or food products leads to several diseases and even death. Recently, studies have been carried out to explore the biochemical and molecular mechanisms which contribute to As toxicity, accumulation, detoxification and tolerance acquisition in plants. This information has led to the development of the biotechnological tools for developing plants with modulated As tolerance and detoxification to safeguard cellular and genetic integrity as well as to minimize food chain contamination. This review aims to provide current updates about the biochemical and molecular networks involved in As uptake by plants and the recent developments in the area of functional genomics in terms of developing As tolerant and low As accumulating plants., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Light-trapping structures are more demanding for optimal light absorption in thin film silicon solar cells. Accordingly, new design engineering of solar cells has been emphasized and found to be effective to achieve improved performance. This paper deals with a design of thin film silicon solar cells and explores the influence of bottom grating and combination of top and bottom (dual) grating as a part of back reflector with a distributed Bragg reflector (DBR). Use of metal layer as a part of back reflector has found to be promising for minimum requirement of DBR pairs. The effect of grating and anti-reflection coating thicknesses are also investigated for absorption enhancement. With optimization, high performance has been achieved from dual grating-based solar cell with a relative enhancement in short-circuit current approximately 68% while it was approximately 55% in case of bottom grating-based solar cell. Our designing efforts show enhanced absorption of light in UV and infrared part of solar spectrum.

Interactive effects of two heavy metal pollutants Cd and Pb in the growth medium were examined on their uptake, production of reactive oxygen species (ROS), induction of oxidative stress and antioxidative defence responses in Indica rice (Oryza sativa L.) seedlings. When rice seedlings in sand culture were exposed to 150 μM Cd (NO3)2 or 600 μM Pb (CH3COO)2 individually or in combination for 8-16 days, a significant reduction in root/shoot length, fresh weight, relative water content, photosynthetic pigments and increased production of ROS (O2˙- and H2O2) was observed. Both Cd and Pb were readily taken up by rice roots and localisation of absorbed metals was greater in roots than in shoots. When present together in the growth medium, uptake of both the metals Cd and Pb declined by 25-40%. Scanning electron microscope (SEM) imaging of leaf stomata revealed that Pb caused more distortion in the shape of guard cells than Cd. Dithizone staining of roots showed localisation of absorbed Cd on root hairs and epidermal cells. Both Cd and Pb caused increased lipid peroxidation, protein carbonylation, decline in protein thiol and increase in non-protein thiol. The level of reduced forms of non-enzymic antioxidants glutathione (GSH) and ascorbate (AsA) and their redox ratios (GSH/AsA) declined, whereas the activities of antioxidative enzymes superoxide dismutase (SOD) and guaiacol peroxidase (GPX) increased in metal treated seedlings compared to controls. In-gel activity staining also revealed increased intensities of SOD and GPX isoforms with metal treatments. Catalase (CAT) activity increased during early days (8 days) of metal exposure and declined by 16 days. Results suggest that oxidative stress is an important component in expression of Cd and Pb toxicities in rice, though uptake of both metals gets reduced considerably when present together in the medium.

The effect of toxic concentrations of aluminum (Al) was investigated on contents of protein-thiols, non-protein and total thiols, protein carbonylation and protease activity in the seedlings of Al-sensitive (Al-S) Indica rice cv. HUR-105 and Al-tolerant (Al-T) cv. Vandana grown in sand cultures. Al treatment of 178 μM and 421 μM for 3-12 days caused a significant decline in the level of protein thiols, rise in non-protein thiols (NPTs) as well as protein carbonyl content and an insignificant alteration in the level of total thiols in cv. HUR-105 seedlings. However, in the seedlings of Al-T cv. Vandana, no significant alteration could be observed on any of these parameters with Al treatment. Al treatment inhibited protease activity in roots, whereas the opposite trend was seen in shoots. New isozymes of protease appeared in shoots of cv. Vandana with increased level of Al treatment. Our results show a link between protein thiols and NPTs and suggest the role of NPTs in the repair and protection of protein thiols. Inhibitory effect of Al on protease activity in roots could be a major reason for Al rhizotoxic effects. Al tolerance in rice appears to be associated with lesser content of protein thiols in roots, smaller amount of carbonylated proteins in roots as well as shoots and higher protease activity in shoots., (Copyright © 2013 Elsevier GmbH. All rights reserved.)

Plant growth and productivity are greatly affected due to changes in the environmental conditions. In the present investigation, the interactive effects of two important abiotic stresses, i.e., water deficit and Al toxicity, were examined in the seedlings of two rice (Oryza sativa L.) cvs. Malviya-36 (water deficit/Al sensitive) and Vandana (water deficit/Al tolerant). When 15 days grown seedlings were exposed to water deficit (created with 15 % polyethylene glycol 6000) or Al (1 mM AlCl3) treatment or both the treatments together for 48 h, the lengths of root/shoot, relative water content, and chlorophyll greatly declined in the seedlings of the sensitive cultivar, whereas in the tolerant seedlings, either little or insignificant decline in these parameters was observed due to the treatments. Seedlings subjected to water deficit or Al treatment alone or in combination showed increased intensity of the isoenzyme activity bands of superoxide dismutase (SOD), guaiacol peroxidase (GPX), and ascorbate peroxidase (APX) in in-gel activity staining studies. Water deficit caused decrease in intensity of catalase (CAT) activity bands; however, when seedlings were exposed to AlCl3 alone or in combination with water deficit, the intensity of the CAT isoforms increased in both the rice cultivars. The level of expression of the activity bands of SOD, CAT, GPX, and APX was always higher in the seedlings of tolerant cv. Vandana compared to the sensitive cv. Malviya-36 under both controls as well as stress treatments. Higher intensity of isozymes representing higher activity levels of antioxidative enzymes in the rice seedlings and their further increase under water deficit, Al exposure, or in combination of both the stresses appears to serve as useful marker for specifying a combination of water deficit and Al tolerance in rice.

Pumpkin (Cucurbita moschata) samples showing yellow vein mosaic disease in Varanasi region were identified with begomovirus infection using PCR amplification. A sequencing analysis of the full genome revealed that it is a strain of Tomato leaf curl Palampur virus (GenBank ID. FJ931537). Phytochemical composition and antioxidative enzyme levels were compared in infected and healthy plants. The study revealed that the amount of total protein declined in the infected leaves but elevated up to 135 % in the fruits of infected plants, whereas vitamin C and antioxidants declined in infected leaves as well as fruits. There was substantial increase in total phenol content in leaves (72 %) and fruits (300 %) of infected plants. In infected samples, substantial increase in activities of superoxide dismutases (SOD), ascorbate peroxidase (APX), guaiacol peroxidase (GPX) and catalase (CAT) was observed as compared to the uninfected control plants. The native PAGE showed alterations in the intensities of isozyme bands in the infected plants. The APX, GPX, CAT, SOD and glutamate dehydrogenase (GDH) bands were intense in the infected plants, whereas the GR isozyme showed reduced intensity in diseased plants.

Aluminum toxicity is a major constraint to crop production in acid soils. The present study was undertaken to examine the comparative ameliorating effects of salicylic acid, Ca and Mg on Al toxicity in rice (Oryza sativa L.) seedlings grown in hydroponics. Al treatment (0.5 mM AlCl3) caused decrease in plant vigour, loss of root plasma membrane integrity, increased contents of O 2 (∙-) , H2O2, lipid peroxidation, protein carbonyls and decline in the level of protein thiol. Al treatment caused significant changes in activity of antioxidative enzymes in rice seedlings. Exogenously added salicylic acid (60 μM), Ca (1 mM) and Mg (0.25 mM) significantly alleviated Al toxicity effects in the seedlings marked by restoration of growth, suppression of Al uptake, restoration of root plasma membrane integrity and decline in O 2 (∙-) , H2O2, lipid peroxidation and protein carbonyl contents. Salicylic acid, Ca and Mg suppressed Al-induced increase in SOD, GPX and APX activities while it elevated Al-induced decline in CAT activity. By histochemical staining of O 2 (∙-) using NBT and H2O2 using DAB, it was further confirmed that added salicylic acid, Ca or Mg decreased Al-induced accumulation of O 2 (∙-) and H2O2 in the leaf tissues. Results indicate that exogenously added salicylic acid, Ca or Mg alleviates Al toxicity in rice seedlings by suppressing Al uptake, restoring root membrane integrity, reducing ROS level and ROS induced oxidative damage and regulating the level of antioxidative enzyme activities. Further salicylic appears to be superior to Mg and Ca in alleviating Al toxicity effects in rice plants.

Water deficit for rice is a worldwide concern, and to produce drought-tolerant varieties, it is essential to elucidate molecular mechanisms associated with water deficit tolerance. In the present study, we investigated the differential responses of nonenzymatic antioxidants ascorbate (AsA), glutathione (GSH), and their redox pool as well as activity levels of enzymes of ascorbate-glutathione cycle in seedlings of drought-sensitive rice (Oryza sativa L.) cv. Malviya-36 and drought-tolerant cv. Brown Gora subjected to water deficit treatment of -1.0 and -2.1 MPa for 24-72 h using PEG-6000 in sand cultures. Water deficit caused increased production of reactive oxygen species such as O2[Symbol: see text](-), H2O2, and HO[Symbol: see text] in the tissues, and the level of production was higher in the sensitive than the tolerant cultivar. Water deficit caused reduction in AsA and GSH and decline in their redox ratios (AsA/DHA and GSH/GSSG) with lesser decline in tolerant than the sensitive seedlings. With progressive level of water deficit, the activities of monodehydroascorbate reductase, dehydroascorbate reductase, ascorbate peroxidase (APX), and glutathione transferase increased in the seedlings of both rice cultivars, but the increased activity levels were higher in the seedlings of drought-tolerant cv. Brown Gora compared to the sensitive cv. Malviya-36. Greater accumulation of proline was observed in stressed seedlings of tolerant than the sensitive cultivar. In-gel activity staining of APX revealed varying numbers of their isoforms and their differential expression in sensitive and tolerant seedlings under water deficit. Results suggest that an enhanced oxidative stress tolerance by a well-coordinated cellular redox state of ascorbate and glutathione in reduced forms and induction of antioxidant defense system by elevated activity levels of enzymes of ascorbate-glutathione cycle is associated with water deficit tolerance in rice.

Global industrial growth has contaminated the soil and water with many hazardous compounds, including heavy metals. These heavy metals are not only toxic to plants but also cause severe human health hazards when leach out into food chain. One of the approaches employed for the decontamination of environment includes identification and overexpression of genes involved in the detoxification mechanism of plants. Glutathione S-transferases (GSTs) are a superfamily of enzymes, principally known for their role in detoxification reactions. Different classes of GSTs have been used to develop plants with improved detoxification mechanism, but not much information is available for Lambda class of GSTs. Here, we studied expression of OsGSTLs in different rice genotypes under arsenic stress. The study suggests differential expression of these genes in arsenic sensitive and tolerant genotypes. Further, the role of one member of Lambda class OsGSTL2 was studied by expressing in heterologous system, Arabidopsis. Transgenic lines developed were analysed for their response to different abiotic stresses including heavy metals. Analysis suggests that OsGSTL2 provides tolerance for heavy metals and other abiotic stresses like cold, osmotic stress and salt. We conclude that OsGSTLs can be utilized for developing plant varieties tolerant to different abiotic stresses including heavy metals., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The effects of increasing concentrations of nickel sulfate, NiSO(4) (200 and 400 μM) in the growth medium on the content of starch and sugars and activity levels of enzymes involved in starch and sugar metabolism were examined in seedlings of the two Indica rice cvs. Malviya-36 and Pant-12. During a 5-20 day growth period of seedlings in sand cultures, with Ni treatment, no definite pattern of alteration in starch level could be observed in the seedlings. In both roots and shoots of the seedlings Ni treatment led to a significant decrease in activities of starch degrading enzymes α-amylase, β-amylase, whereas starch phosphorylase activity increased. The contents of reducing, non-reducing, and total sugars increased in Ni-treated rice seedlings with a concomitant increase in the activities of sucrose degrading enzymes acid invertase and sucrose synthase. However, the activity of sucrose synthesizing enzyme sucrose phosphate synthase declined. These results suggest that Ni toxicity in rice seedlings causes marked perturbation in metabolism of carbohydrates leading to increased accumulation of soluble sugars. Such perturbation could serve as a limiting factor for growth of rice seedlings in Ni polluted environments and accumulating soluble sugars could serve as compatible solutes in the cells under Ni toxicity conditions.

The present investigation evaluated the ability of an antioxidative defense system in terms of the tolerance against salinity-induced oxidative stress and also explored a possible relationship between the status of the components of an antioxidative defense system and the salt tolerance in Indica rice (Oryza sativa L.) genotypes. When the seedlings of a salt-sensitive cultivar was grown in sand cultures containing different NaCl concentrations (7 and 14 dS m(-1)) for 5-20 days, a substantial increase was observed in the rate of superoxide anion (O (2) (·-) ) production, elevated levels of H(2)O(2) and thiobarbituric acid reactive substances (TBARS) which indicated an enhancement in lipid peroxidation. A declination in the level of thiol clearly indicated an increase in the protein oxidation as well as a decline in the reduced forms of ascorbate (AsA) and glutathione (GSH) and the ratios of their reduced to oxidized forms occurred in the salt-sensitive seedlings. Similar treatment caused a very little alteration or no change in the levels of these components in the seedlings of salt-tolerant cultivar. The activity of antioxidative enzymes superoxide dismutase (SOD), its isoform Cu/Zn-SOD and ascorbate peroxidase (APX) increased in both the cultivars against salinity. In salt-sensitive seedlings, the activity of the various enzymes, guaiacol peroxidase (GPX), catalase (CAT), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and glutathione reductase (GR) increased at moderate salinity treatment of 7 dS m(-1) NaCl while the activities of these enzymes declined with higher salinity level of 14 dS m(-1) NaCl. However, a consistent increase was observed in the activities of these enzymes of salt-tolerant seedlings with an increase in the duration and the level of the salinity treatment. The results suggest that a higher status of antioxidants (AsA and GSH) and a coordinated higher activity of the enzymes (SOD, CAT, GPX, APX, and GR) can serve as the major determinants in the model for depicting salt tolerance in Indica rice seedlings.

Sugarcane is a leading energy crop of the world due to its ability to capitulate high sucrose. To understand the mechanism associated with shoot establishment from the lateral bud of sugarcane setts, at the time of germination, we established shoots and these shoots were incubated in total darkness and dark/light regime. The concentration of sugars (sucrose and hexoses) and activities of sugar metabolizing enzymes were measured from 0 to 21 days with 7 days intervals during shoot establishment using sugarcane cultivar CoS 97264. A decrease in sucrose concentration and increase in hexoses level was observed in intermodal tissues whereas in the shoots, the level of both sucrose and hexoses increased continuously during shoot establishment. During 0-21 days shooting period, the dry mass of internodes declined by 20 and 25% in plants incubated in dark/light and darkness respectively. All invertases, soluble acid invertase, neutral invertase and cell wall bound invertase were expressed with almost similar pattern in both the intermodal tissues and the shoots. The activity of enzyme sucrose synthase, measured within first 10 days of shooting in both types of tissues, appeared to be higher particularly in sugar breakdown direction. In the shoots, slight increase in sucrose synthase activity in sucrose synthesis direction was observed throughout shooting period in the shoots. The results suggest that sucrose is the main substrate used during shoot establishment and that shoot establishment period is characterized by increased activities of invertases and sucrose synthase and increased level of hexoses in the shoots., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)

Context: Teeth and restorations are subjected continuously to degradation in hostile physical and chemical environments, resulting in corrosion. Component of liquid or solid is an important factor influencing the corrosion of metallic appliances placed in the oral cavity., Aims: To study in vitro corrosion of titanium wires immersed in solutions of toothpaste and chocolate in artificial saliva., Materials and Methods: Immersion test and electrochemical studies using different parameters, including corrosion potential (E corr ), cathodic Tafel constant (βc), anodic Tafel constant (βa), corrosion current (I corr ), polarization resistance (R p ), and corrosion rate of titanium wires, were done in solutions of artificial saliva containing Colgate™ toothpaste and Amul™ chocolate. Photomicrographs were also taken., Results: The results showed degradation of titanium wires by electrochemical attack when they were placed in the hostile electrolytic environments provided in the experiments. Surface analysis of titanium wires showed pitting and localized attacks on the surface. Pitting corrosion was found in the titanium wires.

The effects of arsenite treatment on generation of reactive oxygen species, induction of oxidative stress, response of antioxidative system, and synthesis of phytochelatins were investigated in two indica rice (Oryza sativa L.) cvs. Malviya-36 and Pant-12 grown in sand cultures for a period of 5-20 days. Arsenite (As(2)O(3); 25 and 50 μM) treatment resulted in increased formation of superoxide anion (O (2) (.-) ), elevated levels of H(2)O(2) and thiobarbituric acid reactive substances, showing enhanced lipid peroxidation. An enhanced level of ascorbate (AA) and glutathione (GSH) was observed irrespective of the variation in the level of dehydroascorbate (DHA) and oxidized glutathione (GSSG) which in turn influenced redox ratios AA/DHA and GSH/GSSG. With progressive arsenite treatment, synthesis of total acid soluble thiols and phytochelatins (PC) increased in the seedlings. Among antioxidative enzymes, the activities of superoxide dismutase (EC 1.15.1.1), catalase (EC 1.11.1.6), total ascorbate peroxidase (APX, EC 1.11.1.11), chloroplastic ascorbate peroxidase, guaiacol peroxidase (EC 1.11.1.7), monodehydroascorbate reductase (EC 1.6.5.4), and glutathione reductase (EC 1.6.4.2) increased in arsenite treated seedlings, while dehyroascorbate reductase (EC 1.8.5.1) activity declined initially during 5-10 days and increased thereafter. Results suggest that arsenite treatment causes oxidative stress in rice seedlings, increases the levels of many enzymatic and non-enzymatic antioxidants, and induces synthesis of thiols and PCs, which may serve as important components in mitigating arsenite-induced oxidative damage.

Pumpkin cultivation in India is affected by severe incidence of a yellow vein mosaic disease. Tomato leaf curl New Delhi virus and Squash leaf curl China virus are known to be associated with this disease in India. We were able to identify a third begomovirus-Tomato leaf curl Palampur virus (ToLCPMV), from pumpkin showing typical symptoms of the disease at Varanasi based on the sequence of complete DNA-A genome of the virus. The complete DNA-A sequence of the virus shared more than 99% sequence identity with other ToLCPMV isolates available in the GenBank and clustered with them in the phylogenetic analysis. This betasatellite amplified from the same infected sample has been identified as Pepper leaf curl betasatellite (PepLCB) which also infects chilli in India. There was 92% sequence identity between the two isolates. This is the first report of natural infection of ToLCPMV on pumpkin and association of PepLCB with yellow vein mosaic disease of pumpkin in India.

When seedlings of rice (Oryza sativa L.) cultivar Pant-12 were raised in sand cultures containing 80 and 160 muM Al(3+) in the medium for 5-20 days, a regular increase in Al(3+) uptake with a concomitant decrease in the length of roots as well as shoots was observed. Al(3+) treatment of 160 muM resulted in increased generation of superoxide anion (O(2) (-)) and hydrogen peroxide (H(2)O(2)), elevated amount of malondialdehyde, soluble protein and oxidized glutathione and decline in the concentrations of thiols (-SH) and ascorbic acid. Among antioxidative enzymes, activities of superoxide dismutase (SOD EC 1.15.1.1), guaiacol peroxidase (Guaiacol POX EC 1.11.1.7), ascorbate peroxidase (APX EC 1.11.1.11), monodehydroascorbate reductase (MDHAR EC 1.6.5.4), dehydroascorbate reductase (EC 1.8.5.1) and glutathione reductase (EC 1.6.4.2) increased significantly, whereas the activities of catalase (EC EC 1.11.1.6) and chloroplastic APX declined in 160 muM Al(3+ )stressed seedlings as compared to control seedlings. The results suggest that Al(3+) toxicity is associated with induction of oxidative stress in rice plants and among antioxidative enzymes SOD, Guaiacol POX and cytosolic APX appear to serve as important components of an antioxidative defense mechanism under Al(3+) toxicity. PAGE analysis confirmed the increased activity as well as appearance of new isoenzymes of APX in Al(3+) stressed seedlings. Immunoblot analysis revealed that changes in the activities of APX are due to changes in the amounts of enzyme protein. Similar findings were obtained when the experiments were repeated using another popular rice cv. Malviya-36.

Removal behaviour of rice hulls was assessed for the removal of Cs-134 from aqueous solutions. Results obtained from batch-type experiments revealed that relatively low uptake of Cs(I) was favoured with increasing the sorptive concentration (from 1 x 10(-8) to 1 x 10(-2) molL(-1)), temperature (298-328), and pH (2.40-10.20). The concentration dependence data fitted well for Freundlich adsorption isotherm. Thermodynamic parameters revealed that the uptake process was endothermic and proceeded via 'ion exchange' along with 'surface complexation'. Moreover, the adsorbed species were not to be desorbed into the bulk concentration even at elevated temperatures, i.e., up to 328 K hence forming a stable adsorption phase. Further, the radiation stability of the rice hulls samples was also assessed by exposing it towards 300 mCi neutron source having the neutron flux of ca. 3.85 x 10(6) ncm(-2)s(-1) associated with nominal gamma-dose of ca. 1.72 Gyh(-1) and indeed it was observed that the rice hulls samples were found to be stable at least for the removal of Cs-134.

When seedlings of two rice (Oryza sativa L.) cvs. Malviya-36 and Pant-12 were raised under 25 and 50 microM As2O3 in the medium an increase in the level of RNA, proteins and proline accompanied with a decline in the level of free amino acid pool was observed under arsenic supplementation compared to controls. In situ As3+ treatment caused a marked inhibition in activities of ribonuclease (RNase, EC 3.1.27.1), protease and leucine aminopeptidase (LAP, EC 3.4.11.1) whereas the activity level of carboxypeptidase (EC 3.4.16.5) was enhanced. In vitro supply of As2O3 in the enzyme assay medium beyond 400 microM resulted in gradual inhibition of RNase and beyond 5 microM inhibition of LAP activities. Addition of 1M proline in the assay medium significantly restored the loss in RNase activity due to in vitro arsenic treatment or due to osmotic stress created by incorporation of polyethylene glycol (PEG). Isoform pattern of RNase extracted from As3+ -exposed seedlings showed a significant alteration compared to its pattern in unexposed seedlings. Results suggest that arsenic exposure impairs hydrolysis of RNA and proteins in rice seedlings due to inhibition of RNase and proteases activities and that proline accumulating under As3+ toxicity appears to serve as enzyme protectant.

Nitrate reductase (NR) activity in the presence of Mg2+ (NR act) representing the non-phosphorylated NR state and the activity in the presence of EDTA (NR max) representing maximum NR activity was measured in roots and shoots of 15 d grown aluminium and water stressed rice seedlings to examine changes in NR activation state due to these stresses. Seedlings subjected to a moderate water stress level of -0.5 MPa for 24 h or grown in presence of 80 microM Al3+showed decreased level of NR max but resulted in higher NR act and NR activation state. However, seedlings grown in presence of a higher level of 160 microM Al3+ showed a decline in NR act as well as NR max. With a higher water stress Level of -2.0MPa a marked decline in the levels of both NR act and NR max was observed, whereas NR activation state remained almost unaltered with severe water stress. NR activity appeared to be sensitive to H2O2, PEG-6000, NaCl and various metal salts. Incorporation of these components in the enzyme assay medium led to decreased affinity of enzyme towards its substrate with increase in Km and decrease in Vmax values. Addition of each of the osmolytes i.e. 1 mol/L proline, 1 mol/L glycine betaine or 1 mol/L sucrose in the enzyme assay medium caused a considerable protection to the enzyme against the damaging effects of stressful components. An enhanced level of proline and glycine betaine was observed in Al-stressed seedlings and sucrose in Al as well as water stressed seedlings. Results suggest that Al toxicity and water stress decrease total amount of functional NR in rice seedlings and the osmolytes proline, glycine betaine and sucrose appear to have a direct protective action on enzyme NR under stressful conditions

We studied in the seedlings of two rice cultivars (Malviya-36 and Pant-12) the effect of increasing levels of arsenic in situ on the content of sugars and the activity of several enzymes of starch and sucrose metabolism: alpha-amylase (EC 3.2.1.1), beta-amylase (EC 3.2.1.2), starch phosphorylase (EC 2.4.1.1), acid invertase (EC 3.2.1.26), sucrose synthase (EC 2.4.1.13) and sucrose phosphate synthase (EC 2.4.1.14). During a growth period of 10-20 d As2O3 at 25 and 50 microM in the growth medium caused an increase in reducing, non-reducing and total soluble sugars. An increased conversion of non-reducing to reducing sugars was observed concomitant with As toxicity. The activities of alpha-amylase, beta-amylase and sucrose phosphate synthase declined, whereas starch phosphorylase, acid invertase and sucrose synthase were found to be elevated. Results indicate that in rice seedlings arsenic toxicity causes perturbations in carbohydrate metabolism leading to the accumulation of soluble sugars by altering enzyme activity. Sucrose synthase possibly plays a positive role in synthesis of sucrose under As-toxicity.

Spices are an important group of agricultural commodities being used by many civilizations all over the world to aid flavor, taste and nutritional values in the food. In traditional medical systems, their ability to heal various physical, mental and emotional problems has widely been reported. With this view, HPLC analysis was performed to estimate phenolic acids in 21 spices (asafetida, Bishop's weed, black mustard, coriander, cinnamon, clove, curry leaf, cumin black, cumin, fennel, fenugreek, garlic, ginger, Indian cassia, Indian dill or dill large cardamom, onion, saffron, tamarind, true cardamom, yellow mustard) commonly used in India in different forms. In all, 7 phenolic acids; viz., tannic, gallic, caffeic, cinnamic, chlorogenic, ferulic and vanillic acids could be identified on the basis of their retention time with standard compounds and co-chromatography. Several parts of the spices, for instance, seeds, leaves, barks, rhizomes, latex, stigmas, floral buds and modified stems were used in the study. Maximum amount of tannic and gallic acids was observed in black mustard and clove. Caffeic, chlorogenic and ferulic acids were found maximum in cumin while vanillic and cinnamic acids in onion seeds. The spices are known to significantly contribute to the flavor, taste, and medicinal properties of food because of phenolics.