Applications of the SR4G Transgenic Zebrafish Line for Biomonitoring of Stress-Disrupting Compounds: A Proof-of-Concept Study

Transgenic zebrafish models have been successfully used in biomonitoring and risk assessment studies of environmental pollutants, including xenoestrogens, pesticides, and heavy metals. We employed zebrafish larva (transgenic SR4G line) with a cortisol-inducible green fluorescence protein reporter (eGFP) as a model to detect stress responses upon exposure to compounds with environmental impact, including bisphenol A (BPA), vinclozolin (VIN), and fluoxetine (FLX). Cortisol, fluorescence signal, and mRNA levels of eGFP and 11 targeted genes were measured in a homogenized pool of zebrafish larvae, with six experimental replicates for each endpoint. Eleven targeted genes were selected according to their association with stress-axis and immediate early response class of genes. Hydrocortisone (CORT)and dexamethasone (DEX) were used as positive and negative controls, respectively. All measurements were done in two unstressed and stressed condition using standardized net handling as the stressor. A significant positive linear correlation between cortisol levels and eGFP mRNA levels was observed (r> 0.9). Based on eGFP mRNA levels in unstressed and stressed larvae two predictive models were trained (Random Forest and Logistic Regression). Both these models could correctly predict the blunted stress response upon exposure to BPA, VIN, FLX and the negative control, DEX. The negative predictive value (NPV) of these models were 100%. Similar NPV was observed when the predictive models trained based on the mRNA levels of the eleven assessed genes. Measurement of whole-body fluorescence intensity signal was not significant to detect blunted stress response. Our findings support the use of SR4G transgenic larvae as an in vivo biomonitoring model to screen chemicals for their stress-disrupting potentials. This is important because there is increasing evidence that brief exposures to environmental pollutants modify the stress response and critical coping behaviors for several generations.

Genetic Variability Screening of the Leptolyngbya Boryana with Expressed ChrR Gene for the Biotransformation of Cr (VI) to Cr (III) Reduction

Chromium is well known pollutant for its mutagenicity, and carcinogenicity in humans. Excessive uses of chromium in leather tanning industries, stainless-steel production, and wood preservatives have resulted as chromium contamination in soil and water. This investigation indicates the effective use of Leptolyngbya boryana as an eco-friendly option to overcome Chromium (VI) toxicity in tannery effluents. The main objective of this research was to find out ChrR gene and its variability in the context of Cr (VI) stress. This is a novel study in the relation of Leptolyngbya boryana. Industrial polluted soil samples were collected and processed according to the standard protocols for ChrR variation and 16S rRNA gene. DNA was isolated and amplified through PCR. Amplified DNA was sequenced and aligned with the known sequences. In this study a strong co-relation was established in the nucleotide sequences of ChrR and 16S rRNA genes. MIC was determined for Cr (VI) and pure strains of Leptolyngbya boryana were identified and isolated from soil. In the present study presence of ChrR gene variability was recorded in Leptolyngbya boryana which is a cyanobacterium in the soil of tannery effluent under Cr (VI) stressed condition and its gene variability was confirmed by sequencing. We can conclude that Leptolyngbya boryana strain could be eco-friendly option to overcome Chromium (VI) toxicity in tannery effluents.

Neither glutamate nor alanine but arginine sensitizes BY-2 cells to arsenate

Arsenic is toxic for plants. Our previous results showed that the application of proline enhanced the sensitivity of tobacco BY-2 cells to arsenate. In order to clarify the enhancement mechanism, we investigated the effects of other amino acids on the arsenate-stressed BY-2 cells. Glutamate at up to 10 mM did not affect the cell growth in the absence or presence of arsenate. Arginine at up to 10 mM did not affect the growth in the absence of arsenate but arginine at 10 mM enhanced the inhibition of the cell growth by arsenate. Alanine at up to 10 mM did not affect the cell growth under non-stressed condition but alanine at 10 mM significantly improved the cell growth under arsenate stress. These results suggest that alanine mitigates arsenate stress in BY-2 cells and that arginine like proline enhances the sensitivity of BY-2 cells to arsenate.

Performance and yield stability of doubled haploid population of wheat (Triticum aestivum L.) under high temperature regime.

India, the second most populated country and the largest wheat producer worldwide, is vulnerable to global warming especially heat stress. In the present investigation, the doubled haploid population derived from PBW343/IC252478 cross was characterized for various phenotypic and morpho-physiological traits and subjected to stability analysis under heat stress conditions. These lines were planted on a single location i.e., Agricultural farm of Rajendra Prasad Central Agricultural University, India for two successive seasons 2017/2018 and, 2018/2019 under three different sowing dates (Controlled or timely, late and, very late sown conditions). Here, the location preferred for this study was because it represents a hotspot for wheat production and the major constraint for the wheat grower is inclining heat stress. The alpha lattice design was used for the current investigation with three replicates. The overall objective of this study was to identify the ideal double haploid lines for heat-stressed conditions. The results revealed that heat stress had a significant adverse impact on all considered traits contributed to overall yield losses of about 50%. Stability measurements, and genotype × environment interaction (GGE), were useful tools to determine the ideal lines for late sowing (heat stressed condition) and very late sowing condition (terminal heat stress). Therefore, in the ranking of genotypes for both mean yield and stability performance across the six environments, DH 71, DH 150, DH 64, DH 138, DH 98, DH 84, DH 62, DH 104, DH 74, DH 3, DH 104, DH 107 & DH 156 were ranked closest to ideal genotype, these were highly adapted, most stable, heat tolerant and high yielding lines indicating them as the most desirable genotypes out of 167 lines studied. Hence, the physiological traits SPAD index (Soil plant analysis development) and Canopy temperature (CT) can be used effectively to screen out the line for heat tolerance. In addition, the stable wheat genotypes identified could be used in the future wheat breeding programs.

ALLEVIATION OF CHANGES IN GROWTH AND PHYSIOCHEMICAL PARAMETERS IN SALT (NACL) STRESSED OF TWO SESAME (SESAMUM INDICUM L) VARIETIES

Present research was carried out with the aim of identifying effect of salt stress (NaCl 0(Control), 40, 80, and 120 mM) on growth and physiochemical parameters of sesame (Sesamum indicum L.) variety CO-1 and KRR-2. Various parameters such as height of the plant, leaf area, fresh weight of the whole plant and dry weight of whole plant and decreased the content of physiochemical parameters were analyzed. All the parameters were recorded at 30th Days after Treatment (DAT). Analysis revealed a significant reduction in all parameters with increased salt concentration. This experiment carried out fully pot culture methods. Severity of salinity stressed condition were also observed with increased salinity concentration level at the same time decrease in all growth parameter were non-significant in stressed plant as compared two sesame varieties CO-1 and KRR-2. CO-1 in the sesame varieties at 120mM high salt concentration increased with lower decreased was observed in height of the plant, Leaf area, fresh weight of the whole plant and dry weight of whole plant and decreased the content of physiochemical parameters compared to other sesame varieties KRR-2 under salt stress condition. The results indicated that plants of sesame variety CO-1 exhibited higher adaptive potential under salinity stress as judged by higher growth and higher content of physiochemical parameters when compared to variety KRR-2.

Trimetazidine Topical Delivery Prevents Carrageenan Induced Retinal Damage and Glucose Induced Lens Opacification by Decreasing Drop of Protein Level

Carrageenan induced oxidative stress develops retinal damage and increases lipid peroxidation. Glycation of the lens proteins increases modified proteins and may affect the lens structural integrity and opacification, after increasing glucose concentration in the lens. Trimetazidine (TZ) has been reported to have cytoprotective anti-ischaemic activity after systemic administration in an animal model. Trimetazidine ophthalmic film formulation has been prepared using HPMC as the hydrogel-forming polymer. The cytoprotective role of trimetazidine has been studied on carrageenan-induced retinal damage of rat eye by histologicaland Malondialdehyde (MDA) assay applying sterilized film formulation. Trimetazidine solution was used in combination with a high concentration of glucose solution (55 mM) for examining the protective effect from cataract formation. Formulation showed controlled and extended ophthalmic permeation of the drug for about 5 h. Damage of retinal cells in the ganglionic layer has been decreased significantly in the trimetazidinetreated group. Drug treated control group also showed significant disappearance of pyknotic cells. The addition of trimetazidine to the glucose medium practically retarded the lens opacification by reducing the over-production of reactive oxygen species (ROS) in increased sugar concentration. Presence of trimetazidine probably decreased the drop of protein level in lens under stressed condition and greater preventive effect has been noticed with TZ concentration of 240 µg/ml rather than 120 µg/ml. Trimetazidine ophthalmic film formulation could prevent retinal damage and cataract formation.

Assessing the Maize (Zea mays L.) Crop Performance Using Spectral Indices under Different Sowing Dates and Irrigations Schedules

Field experiment was conducted at ARI, PJTSAU, Hyderabad with four dates of sowing (18th June, 04th July, 19th July and 03rd August in Kharif, 2016 and 01st November, 18th November, 01st December and 17th December in rabi, 2016–17) as main plots and four irrigations regimes (Control, 0.4 IW/CPE, 0.6 IW/CPE and 0.8 IW/CPE in kharif and 0.4 IW/CPE, 0.6 IW/CPE, 0.8 IW/CPE and 1.0 IW/CPE in rabi) as sub-plots in split plot design replicated thrice. Scheduling irrigation at unstressed conditions, 0.8 IW/CPE (I3) and 1.0 IW/CPE (I4) of maize resulted in low reflectance in visible region (400 to 700 nm) and mid infrared (MIR) region (1350–2500 nm) and high in near infrared (NIR) region (700 to 1350 nm) during kharif and rabi respectively. While, under stressed condition, the reflectance was high in visible and MIR region and low in NIR region in rainfed and 0.4 IW/CPE (I0) respectively in kharif and rabi. Significantly higher drymatter, LAI and grain yield was observed in 04th July (D2) and 01st November (D1) sown crop in kharif and rabi respectively. However, spectral indices (SR, PRI, NDWI at 1240, 1640 and 2130 nm, NDII, NMDI, WBI and SWRI) was attained by 18th June (D1) and 01st November (D1) during kharif and rabi respectively. Higher drymatter, LAI, grain yield and spectral indices was recorded with I3 (0.8 IW/CPE) and I4 (1.0 IW/CPE) in kharif and rabi respectively. All the spectral vegetation indices correlated positively with LAI, drymatter and grain yield.

Silicon Mediated Changes in Growth and Photosynthetic Pigment of Wheat Plant Under Salt Stress

Purpose Salinity is a most important environmental stress which adversely affects the crop production and yield. In recent years, Silicon (Si) is gaining an increased attention in the field of stress management. Wheat (Triticum aestivum L.) is one of the moderately prone crops to different abiotic stresses which instantly damage the crop yield under stress condition. This work demonstrates the positive impact of Si on growth and photosynthetic pigments in wheat under saline conditions.Methods In this research work, two genotypes of wheat i.e. KRL 210 and WH 1105, were grown-up in soil under different salt stress concentration. There were different treatments under which they grown included T0= Control without salt stress (0 dS m-1) , T1= Sodium silicate without salt stress (2 mM) , T2= Control with salt stress (4 dS m-1) T3= Control with salt stress (8 dS m-1) T4= Control with salt stress (12 dS m-1) T5= Sodium silicate with salt stress (4dS m -1 + 2mM Si) T6= Sodium silicate with salt stress (8dS m-1 +2 mM Si) T7= Sodium silicate with salt stress (12dS m-1 +2mM Si). At vegetative stage, both the wheat genotypes were compared with their growth parameters and photosynthetic pigments.Results Plant biomass, shoot-root length and photosynthetic pigments (chlorophyll- a, b, carotenoid & total chlorophyll) of wheat decreased under salt stress when increased up to 12 dS m-1 NaCl concentration. However, in salt stressed wheat plants, plant biomass increased by the Si application. Supplementation of Si improved the plant length as well as chlorophyll pigments which were decreased by the high salt concentration in plants. Silicon was found more effective in salt stressed condition than in alone with control.Conclusion So, it was determined that the Si application aided the wheat genotypes in alleviating salinity and enhancing their biomass and photosynthetic pigments which were declined in salt stress condition.

Evaluation of Traits’ Performance Contributing to Drought Tolerance in Sorghum

Sorghum (Sorghum bicolor [L.] Moench) is an important food crop for people in semi-arid Africa. The crop is affected by post-flowering drought; therefore, the study was conducted to screen traits contributing to drought tolerance using BC2F4 sorghum genotypes in stressed and unstressed water conditions in a split-plot design. Water stress (0 mm/day) was applied at post-flowering to plant maturity in water-stressed treatment. The genotype SE438 produced the highest grain yield (2.65 ton ha−1) in water-stressed environment and NA316C yielded highest (3.42 ton ha−1) under well-watered (7 mm/day) environment. There were significant differences of most traits evaluated at p < 0.01 across environments. The mean squares of traits for genotypes by environments revealed interactions at p < 0.05 and p < 0.01. The indices geometric mean productivity (GMP) and mean productivity (MP) were highly correlated with yield under well-watered (YP) and water-stressed condition (YS) and each other. The first principal axis (PC1) explained 59.1% of the total variation. It is the best indicator of yield potential and drought tolerance of sorghum genotypes in this study. Therefore, further improvement is needed to strengthen drought tolerance and yield in sorghum.

Nonlinear oscillations of particle-reinforced electro-magneto-viscoelastomer actuators

This work presents the dynamic modeling and analysis of a particle-reinforced and pre-stressed electro-magneto-viscoelastic plate actuator. The actuator belongs to a smart actuator category and is made of an electro-magneto-active polymer filled with a particular volume fraction of suitable fillers. An energy-based electro-magneto-viscoelastic model is developed to predict the actuator response and interrogate the impact of particle reinforcement on the dynamic oscillations of a pre-stressed condition of the actuator. An Euler–Lagrange equation of motion is implemented to deduce the governing dynamic equation of the actuator. The findings of the model solutions provide preliminary insights on the alteration of the nonlinear behavior of the actuator excited by DC and AC dynamic modes of actuation. It is observed that the enrichment in the particle reinforcement characterized by the amount of fillers strengthens the polymer and depleted the associated level of deformation. Also, the depletion in the intensity of oscillation and enhancement in the frequency of excitation is perceived with an increase in the particle reinforcement. In addition, the time-history response, Poincare plots and phase diagrams are also plotted to assess the stability, periodicity, beating phenomenon, and resonant behavior of the actuator. In general, the current study provides initial steps toward the modern actuator designs for various futuristic applications in the engineering and medical field.