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We report the synthesis of two pyridinium‐based room temperature protic ionic liquids (PILs), pyridinium bisulfate, [HPyr][HSO4] and pyridinium sulphate, [HPyr]2[SO4] and investigation of the kinetics of their water sorption behaviour and its influence on their density, ionic conductivity, and potential windows. The PILs were synthesized by the reaction of pyridine base with an acid, H2SO4, under solventless conditions, and confirmed by FTIR spectroscopy and 1H NMR spectra. The appearance vibration bands in the 3095–3252 cm−1 range for −NH+ stretching in the FTIR spectra and a peak at a chemical shift of 8.439 ppm in the 1H‐NMR of the liquids confirm their synthesis as no such bands/peaks can be seen in that of the pure pyridine spectra. The PILs’ hygroscopic nature was examined by exposing them (5 mL each sample with exposed surface area 3.143 cm2) to air for varied time intervals at a relative humidity, RH=58±5 % and T=20±5 °C. Coulometric Karl‐Fischer (KF) titration was used to determine how much moisture each PIL sample absorbed at each time interval. The findings reveal that when the PIL was exposed to air for longer periods of time, more moisture was absorbed, and the results correspond well with the pseudo first‐order kinetic model. The densities and conductivities of several samples of the two PILs were examined, and it was discovered that as the percentage water content of the PILs grew, density decreased but conductivities increased. Furthermore, it was discovered that when temperature rose, the conductivity of each of the PILs increased, and the results fit well to the Arrhenius linear equation since the regression coefficient, R2, for each of the samples approached the perfect fit value of one. The electrochemical window (EW) data, the mechanism of moisture oxidation within the EWs of each PIL at Pt and Au electrodes, and the electrocatalytic role played by the Pt and Au surface oxides during ethanol oxidation are evaluated and discussed in light of their future sustainable energy applications. [ABSTRACT FROM AUTHOR]

Selenium is an essential trace element required for seleno-protein synthesis in many eukaryotic cells excluding higher plants. However, a substantial fraction of organically bound selenide in human nutrition is directly or indirectly derived from plants, which assimilate inorganic selenium into organic seleno-compounds. In humans, selenium deficiency is associated with several health disorders Despite its importance for human health, selenium assimilation and metabolism is barely understood in plants. Here, we analyzed the impact of the two dominant forms of soil-available selenium, selenite and selenate, on plant development and selenium partitioning in plants. We found that the reference plant Arabidopsis thaliana discriminated between selenate and selenite application. In contrast to selenite, selenate was predominantly deposited in leaves. This explicit deposition of selenate caused chlorosis and impaired plant morphology, which was not observed upon selenite application. However, only selenate triggered the accumulation of the macronutrient sulfur, the sister element of selenium in the oxygen group. To understand the oxidation state-specific toxicity mechanisms for selenium in plants, we quantified the impact of selenate and selenite on the redox environment in the plastids and the cytosol in a time-resolved manner. Surprisingly, we found that selenite first caused the oxidation of the plastid-localized glutathione pool and had a marginal impact on the redox state of the cytosolic glutathione pool, specifically in roots. In contrast, selenate application caused more vigorous oxidation of the cytosolic glutathione pool but also impaired the plastidic redox environment. In agreement with the predominant deposition in leaves, the selenate-induced oxidation of both glutathione pools was more pronounced in leaves than in roots. Our results demonstrate that Se-species dependent differences in Se partitioning substantially contribute to whole plant Se toxicity and that these Se species have subcellular compartment-specific impacts on the glutathione redox buffer that correlate with toxicity symptoms.

The widespread deficiency of iron (Fe) and sulfur (S) is becoming a global concern. The underlying mechanisms regulating Fe and S sensing and signaling have not been well understood. We investigated the crosstalk between Fe and S using mutants impaired in Fe homeostasis, sulfate assimilation, and glutathione (GSH) biosynthesis. We showed that chlorosis symptoms induced by Fe deficiency were not directly related to the endogenous GSH levels. We found dynamic crosstalk between Fe and S networks and more interestingly observed that the upregulated expression of IRT1 and FRO2 under S deficiency in Col-0 was missing in the cad2-1 mutant background, which suggests that under S deficiency, the expression of IRT1 and FRO2 was directly or indirectly dependent on GSH. Interestingly, the bottleneck in sulfite reduction led to a constitutively higher IRT1 expression in the sir1-1 mutant. While the high-affinity sulfate transporter (Sultr1;2) was upregulated under Fe deficiency in the roots, the low-affinity sulfate transporters (Sultr2;1, and Sultr2;2) were down-regulated in the shoots of Col-0 seedlings. Moreover, the expression analysis of some of the key players in the Fe–S cluster assembly revealed that the expression of the so-called Fe donor in mitochondria (AtFH) and S mobilizer of group II cysteine desulfurase in plastids (AtNFS2) were upregulated under Fe deficiency in Col-0. Our qPCR data and ChIP-qPCR experiments suggested that the expression of AtFH is likely under the transcriptional regulation of the central transcription factor FIT.

Organic dyes used to shade numerous materials on an industrial level causes water pollution. To meet the need for the removal of the dye-laden water the mechanistic methodology is developed in which catalyst (ZnO), oxidizer (H2O2), and irradiation of low dose (4 KGy) are involved. Oxidizers and catalysts are characterized for surface morphology by SEM, functional groups by FTIR, crystallinity by XRD, particle size by PSA, and for elemental ratio by EDX. A solution ranging from 2 ppm to 8 ppm of Congo red (CR) dye, ZnO (100 μg) as a catalyst, H2O2 (100 μL), as an oxidizer, and 4 KGy energy radiations were used during the degradation analysis for 30, 60, 90, and 120 min. The enhanced effect is shown by using the oxidizer, catalyst, and irradiation at a time. Moreover, it shows a degradation of 99 % for 2 ppm and 4 ppm within 60 min while 6 ppm almost 99 % within 90 min, and 8 ppm almost 96.76 % within 120 min. The established mechanistic methodology can also be applied to actual aqueous industrial samples. [ABSTRACT FROM AUTHOR]

Phytohormone abscisic acid (ABA) is the canonical trigger for stomatal closure upon abiotic stresses like drought. Soil-drying is known to facilitate root-to-shoot transport of sulfate. Remarkably, sulfate and sulfide—a downstream product of sulfate assimilation—have been independently shown to promote stomatal closure. For induction of stomatal closure, sulfate must be incorporated into cysteine, which triggers ABA biosynthesis by transcriptional activation of NCED3. Here, we apply reverse genetics to unravel if the canonical ABA signal transduction machinery is required for sulfate-induced stomata closure, and if cysteine biosynthesis is also mandatory for the induction of stomatal closure by the gasotransmitter sulfide. We provide genetic evidence for the importance of reactive oxygen species (ROS) production by the plasma membrane-localized NADPH oxidases, RBOHD, and RBOHF, during the sulfate-induced stomatal closure. In agreement with the established role of ROS as the second messenger of ABA-signaling, the SnRK2-type kinase OST1 and the protein phosphatase ABI1 are essential for sulfate-induced stomata closure. Finally, we show that sulfide fails to close stomata in a cysteine-biosynthesis depleted mutant. Our data support the hypothesis that the two mobile signals, sulfate and sulfide, induce stomatal closure by stimulating cysteine synthesis to trigger ABA production.

Cadmium (Cd) is toxic to the ecosystem even at low concentrations. To mitigate Cd toxicity as well as to enhance plant growth, endophytes extracted from different sources have been effectively used. In the current study, the role of an endophytic bacterial strain Serratia sp. IU01, in alleviating Cd toxicity and promoting growth was evaluated in Brassica juncea in the hydroponic system. Cd stress significantly reduced the growth attributes (root/shoot length and biomass) of the host plant in comparison to control plants. A significant increase was observed in the shoot, root length and biomass of B. juncea plants inoculated with Serratia sp. IU01 (9.8 ± 0.28 cm, 12.16 ± 1.44 cm, 299.5 ± 39.5 mg, respectively) compared to control (8.6 ± 0.28 cm, 7.16 ± 0.76 cm, 125.27 ± 5.40 mg, respectively), sole Cd-treated (5.5± 0.5 cm, 4.33± 1.15 cm, 103.73 ± 7.18 mg, respectively), and inoculated Cd-treated plants (5.67± 0.58 cm, 6± 1.53 cm, 137.33 ± 6.66 mg, respectively). Growth parameters were retrieved in inoculated plants under Cd stress but the differences were non-significant in comparison to the un-inoculated Cd-treated plants. High-performance liquid chromatography (HPLC) analysis revealed significantly elevated steady-state levels of one of the most abundant versatile antioxidant molecules in the cell i.e., glutathione (GSH) in response to Cd stress. However, under Cd stress, inoculation of the plants with Serratia sp. IU01 led to a significant decrease in roots' GSH contents (75 ± 15.56 pmol mg-1 FW) compared with the un-inoculated Cd-treated (141 ± 7.2 pmol mg-1 FW) and control set of plants (123.6 ± 1.2 pmol mg-1 FW) presumably via the release of antioxidants by the endophytes in the roots of internal tissues of the host plant. These results demonstrated the potential of Serratia sp. IU01 in mitigating Cd-induced toxicity and promoting plant growth in Cdpolluted environments. [ABSTRACT FROM AUTHOR]

This research was conducted to determine inbreeding depression in S1 maize lines for reproductive and yield related traits, at NWFP Agricultural University, Peshawar, Pakistan, in two successive seasons during 2002. Maize variety"Pahari" was selfed for one generation and 63 S1 lines were evaluated using "lattice square design" with two replications along with the parental population. Days to mid silking and mid pollen shed (anthesis), plant height and ear height (cm), and 200 grain weight (g) showed inbreeding depression with varying degrees. Severe inbreeding depression was observed for yield with the average of 709 kg ha-1. Inbreeding depression for 200 grains weight averaged 19 g, while for plant height and ear height it was calculated as 33 and 16 cm. Inbreeding depression for days to mid silking and pollen shed was lower as compared to morphological and yield components. Silking and pollen shed were delayed by 1.8 and 1.5 days on the average, respectively, as compared to the parental variety. Yield was significantly correlated with all maturity and morphological characters. Maturity characters were positively and significantly correlated with each other, showing good synchronization in maturity characters, while they were negatively and significantly correlated with yield components.

The experiment was conducted at NWFP Agricultural University, Peshawar to study heterosis and inbreeding depression in 7×7 half diallel crosses of sunflower. The planted materials consisted of parental inbred lines, their F1 hybrids and F2 populations using randomized complete block design with three replications. Data were recorded on yield and other important agronomic characters. Significant genetic differences were observed among the parents, their F1 hybrids and F2 populations for all the characters under study. Yield and leaf area showed highly significant heterosis in F1 hybrids ranging from 102 to 309% and46.3 to 163.9%, respectively, while inbreeding depression in the F2 population ranged from 17-71% and -9.7-43%, respectively. Leaves per plant showed low level of heterosis in F1 hybrids (-0.9 to 39.7%), whereas the effect of inbreeding depression in F2 population was comparatively high (1.1 to 22.2%) for this character. The parent RHA-822 proved itself to be a good general combiner by making higher contribution towards heterosis both in F1 hybrids and in F2 populations.

Among the toxic heavy metal(loid)s, cadmium (Cd) and arsenic (As) have devastating effects on crop productivity and human health. In plants, mechanisms of detoxification of Cd and As proceed via a glutathione (GSH) dependent common pathway, despite their different modes of toxicity. In this context, the present study aimed to investigate how the common detoxification mechanisms for Cd and As influence the physiological and biochemical responses of seedlings of an important plant used for phytoremediation purposes, Brassica juncea, under Cd and As stress.We demonstrated that Cd and As trigger mostly distinct, but partly overlapping, responses in B. juncea. Exposure of B. juncea seedlings to 100 µM Cd stress for 12 days in a hydroponic system led to a significant reduction in the growth of roots and shoots, and in total chlorophyll content. However, As stress caused a decline in root length only. High-performance liquid chromatography analyses revealed a significant increase in cysteine levels in roots and shoots in response to As stress compared with control and Cd-treated plants. Concomitant elevated sulfur content in response to As stress was observed in roots and shoots. In terms of GSH content, Cd and As triggered similar responses, with a significant decrease in GSH in roots, and non-significant changes in shoots, compared with untreated plants. Inductively coupled plasma-atomic emission spectroscopy revealed that under Cd stress, plants preferentially accumulated zinc (Zn) in the roots compared with iron (Fe) and manganese (Mn). Responses in roots under As and Cd stress were similar with respect to Fe accumulation but opposite in terms of Zn and Mn accumulation. Our data provide valuable insights for design of future strategies for sustainable plant growth on As and Cd polluted soils. [ABSTRACT FROM AUTHOR]

Protic ionic liquids (PILs) being intrinsic proton conducting ionic species are considered as potential green electrolytes for study of electrocatalytic reactions and for fabrication of IL-based fuel cells (FCs) and batteries. We have prepared a sulfate anion based protic ionic liquid (PIL), triethylammonium sulfate (TEAS) through a reaction involving transfer of proton from H2SO4 to triethylamine (TEA). 1H NMR and FT-IR spectroscopic techniques were employed for confirmation of the synthesis of TEAS and water content of the PIL was quantified using coulometric Karl–Fischer (KF) titration. 1H NMR and FT-IR analysis confirm the synthesis of the PILs and KF-titration analysis shows that TEAS contains 1.43 w/w % water. Electrical conductivity of TEAS was determined at different temperatures showing that the PIL has excellent ionic conductivity that enhances with rise in temperature of the medium. The temperature dependence of the conductivity of the PIL follows the Arrhenius equation as the logσ versus 1/T plot is linear. The electrochemical windows (EWs) of the electrolyte were found using cyclic voltammetry at Pt and Au working electrodes and found to decrease with increase in temperature of the medium. The data revealed that the surfaces of the electrodes are covered with oxide layers due to oxidation of trace water (1.43 w/w %) present in the PIL. The oxide layers growth increase and their onset potential moves to less positive values as the temperature of the PILs is increased. The data was compared with the literature and would be helpful in understanding of the surface electrochemistry in this neoteric medium for being used as potential electrolyte in industry for various electrochemical applications. [ABSTRACT FROM AUTHOR]

The in-situ stabilization of Ag nanoparticles is carried out by the use of reducing agent and synthesized three different types of hydrogen (anionic, cationic, and neutral) template. The morphology, constitution and thermal stability of the synthesized pure and Ag-entrapped hybrid hydrogels were efficiently confirmed using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and thermo gravimetric analysis (TGA). The prepared hybrid hydrogels were used in the decolorization of methylene blue (MB) and azo dyes congo red (CR), methyl Orange (MO), and reduction of 4-nitrophenol (4-NP) and nitrobenzene (NB) by an electron donor NaBH4. The kinetics of the reduction reaction was also assessed to determine the activation parameters. The hybrid hydrogen catalysts were recovered by filtration and used continuously up to six times with 98% conversion of pollutants without substantial loss in catalytic activity. It was observed that these types of hydrogel systems can be used for the conversion of pollutants from waste water into useful products. [ABSTRACT FROM AUTHOR]