Physiological responses of sub1A QTL under induced dehydration stress for varying days in rice

This study analysed the rice genotype with sub1A quantitative trait loci that may interact with ongoing exposure of dehydration. cv. Swarna Sub1 had more nutrients efficiency with increased membrane permeability than cv. Swarna. sub1A QTL with its expression to water / osmotic deficit, however, indirectly to impede the oxidative stress under dehydration might help cv. Swarna Sub1. At maximum dehydration cv. Swarna Sub1 had 1.12 fold excess electrolyte leakages than cv. Swarna under dehydration. cv. Swarna Sub1 had better Nicotinamide adenine dinucleotide phosphate-malic enzyme activity to secure carbon dioxide exchange. A proportional increase in enzyme activity all through dehydration stress maximize under light in cv. Swarna Sub1. At maximum dehydration cv. Swarna Sub1 at saturating substrate concentration was increased by 1.12 fold than other cultivar. The ratio of glutathione (GSH:GSSG) more depleted in cv. Swarna Sub1 through the dehydration period. cv. Swarna could be more promising to retrieve the activity by 1.80 fold than cv. Swarna Sub1 under maximum dehydration. Dehydroascorbate reductase activity was also maintained in cv. Swarna with 1.20 fold ahead than cv. Swarna Sub1 under same condition. As a biomarker of oxidative stress cv. Swarna Sub1 appeared to be less sensitive with the loss of protein oxidation, however, recorded with 25% less carbonyl content than cv. Swarna. Both the genotypes had scored a significant sensitivity with tissue specific distribution for reactive oxygen species as detected by histochemical assay

Modalities of NADP-malic enzyme activities under light and darkness indicate its regulation with reference to C4 weed

NADP –ME is the key enzyme for decarboxylation reactions in C4 CO2 concentration pathways. So, Amaranthus viridis has been evaluated with regards to photosynthetic NADP-malic enzyme for its response under light and darkness. Illumination (1000–1200 µEm-2s-1) for 40 minutes under 2 mM bicarbonate (HCO3-) sensitivity increased activity by 1.97 & 3.77-fold over darkness under 4.0 mM and 0.01 mM malate respectively. Limiting (0.01 mM) and saturated (4.0 mM) malate concentration had significant changes in enzyme activities. The different kinetic parameters indicated had the feedback inhibition under illumination. The activity with the inducer (citrate and succinate) and inhibitor (pyruvate and oxalate) was significant with substrate concentrations. Dithiol had reduced the activity by inhibition of the diminishing effect of light activation treatment. Therefore, NADP-ME is stringently regulated by redox changes with illumination as a key factor. Moreover, the pattern of polymorphic gene expression may be supportive in molecular modulation under light/darkness. This study may support the role of NADP-ME as a biomarker for C4 weed species under oxidative stress through light/darkness

Cellular response of oxidative stress when sub1A QTL of rice receives water deficit stress

In this experiment, sub1A quantitative trait loci (sub1A QTL) of rice were evaluated for dehydration responses through different aspects of cellular responses. Through variations of dehydration exposure, rice seedlings recorded a significant increase in superoxide (O2.-) and hydrogen peroxide (H2O2), the former by 1.80 fold and the latter by 2.10 fold. Nicotinamide adenine dinucleotide phosphate oxidase activity fairly correlated with lipid peroxidation (r = 1.96). Both 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) had similar IC50 values over the control at p ? 0.05. Reducing power of the extract had 1.31 fold increase. The antioxidant moieties like total phenolics and flavonoids were 1.04 and 1.23 fold upregulated under stress. On the other hand anthocyanin and glutathione (GSH) did not vary much under stress except at maximum duration of stress. Superoxide dismutase (SOD) was initially stable but maximized at 8 days by 1.30 fold increase. On the contrary, guaiacol peroxidase (GPX) was seen to be downregulated by 40.94% all through the days of stress. Catalase (CAT) activity followed a similar trend, but was not significant as compared to control

The direct and indirect impact of SARS-CoV-2 infections on neonates: a series of 26 cases in Bangladesh

Background: The impact of SARS-CoV-2 on neonates remains largely unknown in low- and middle-income countries (LMICs). We provide an epidemiologic and clinical report of SARS-CoV-2 infections in neonates hospitalized in Bangladesh. Methods: Outborn neonates admitted to Dhaka Shishu Hospital, a tertiary-care referral hospital, between 29 March and 1 July were screened for SARS-CoV-2. We reviewed clinical data, including chest radiograph and laboratory reports, and conducted SARS-CoV-2 genome sequencing. Patients were followed-up for 27–75 days. A subset of caregivers was also tested. Results: Of 83 neonates tested, 26 were positive (median age 8 days). Most neonates were admitted with diagnosis unrelated to SARS-CoV-2: 11 presented with serious non-communicable diseases, 7 with early-onset sepsis, 5 with late-onset sepsis and 2 with pneumonia. In 3 of 5 chest radiograph, infiltrates and ground-glass or patchy opacities were noted. Two neonates developed metabolic acidosis, one developed disseminated intravascular coagulation. Most SARS-CoV-2 positive neonates were referred to government-designated COVID-19 hospitals, leading to gaps in treatment. Twenty-three neonates could be followed-up: 12 were healthy, 8 died and 3 were still seeking medical care. Of 9 caregivers tested, 8 were positive. Conclusions: SARS-CoV-2 may have serious adverse effects on children born in LMICs. The virus likely contributed directly to two deaths, but the remaining 6 neonates who died had serious comorbidities. Positive SARS-CoV-2 test results led to gaps in immediate clinical care for other morbidities, which likely contributed to adverse outcomes. This case series emphasizes the need to understand COVID-19 in neonates in LMICs and its indirect impacts

Original scientific paper Study of solute–solvent interactions of nicotinic acid and benzoic acid in methanol and its binary solvent systems

Abstract: The apparent molar volumes, φV, and viscosity B-coefficients, B, fo

Conductance studies on some alkali metal acetates in aqueous glycerol solutions

63-68Molar conductance of lithium acetate, sodium acetate, potassium acetate, sodium bromide, sodium tetraphenylborate and tetrabutylammonium bromide in a series of glycerol + water mixtures at temperatures from 298.15 K to 318.15 K has been reported. The limiting polar conductances, association constants and cosphere diameter have been derived from the Lee-Wheaton conductivity equation. The limiting ionic conductivities have been calculated by reference electrolyte method. Ionic conductivities of cations and anions are discussed in terms of solvent viscosity, the Stokes radii and ion-ion and ion-solvent interactions. The small values of association constants for all the electrolytes studied indicate their weak association in aqueous glycerol mixtures, which is in line with the high dielectric constants of the solvent media

Physiological characterization of SUB1 trait in rice under subsequent submergence and re-aeration with interaction of chemical elicitors

In the present study, the sensitivity of two chemical elicitors: polyamine (PA) and salicylic (SA) acid were exercised for submergence sensitivity in Swarna Sub1A rice variety. Under 5 days of submergence, the antioxidation responses were more distinguished in plants against control. Along with the anti-oxidation modules, significant changes in biomolecule loss were registered through lipid and protein oxidation by 1.91 and 1.46 -fold respectively. PA and SA treated plants were the reliever to recover the membrane potential. Total carbohydrate and reducing sugars were varied under submergence by down regulation of 36.66 and 44.44% as compared to control. This was also supported by regulation of ?-amylase activity under submergence that also recovered significantly with PA and SA treatments against submergence. In association with carbohydrate metabolism, Under submergence Swarna Sub1A recorded to be prone with oxidative stress through O2.- (1.55 fold) and peroxide (1.70-fold) over-accumulation but recovered as PA and SA applied. In both cases, sustenance of non-enzymatic anti-oxidant like total carotenoid and lycopene content were also contributory through down-regulation. The enzymatic anti-oxidation paths like SOD, GPX, CAT and GR were regulated by 11.11, 19.54, 13.65, 10.03% declined respectively and thoroughly discussed with reference to PA and SA interactions

Insights into the mechanism of abscisic acid-induced 2, 4-D tolerance in maize (Zea mays L.) seedlings: Study on the regulation of osmolytes, fluorescence, photosynthetic carbon reactions, and antioxidant metabolism

In this experiment, maize plants were subjected to different concentrations (0, 50, 100, and 250 µM) of the herbicide 2, 4-dichlorophenoxyacetic acid (2, 4-D), with some groups primed with abscisic acid (ABA) and others not. Initial observations showed that after five days of incubation, seedlings exposed to the highest concentration of 2, 4-D exhibited stunted growth and a reduction in chlorophyll accumulation. Key parameters such as relative water content, relative growth rate, and net assimilation rate decreased (by 25%, 39%, and 35% respectively) under this condition. However, these parameters partially recovered with ABA priming, showing average improvements (8%, 14%, and 16%). Recovery in tissue hydration was also noted, coinciding with increased concentrations of proline (Pro) and glycine betaine (GB), and a decrease in the Na+/K+ ratio. When exposed to the highest concentration of the herbicide, fluorescence activity was reduced, but this too was reversed with ABA treatment. A notable inhibition of photosynthesis occurred, particularly at the decarboxylation reactions involving NADP-malic enzyme and phosphoenolpyruvate carboxylase, affecting total sugar concentrations. Under the influence of 2, 4-D, there was a significant increase in reactive oxygen species, such as superoxide (35%) and hydrogen peroxide (78%), but these levels significantly diminished with ABA priming. Abscisic acid priming also mitigated oxidative stress, evidenced by a reduction in malondialdehyde (by 10%) and carbonyl content (by 11%), along with lower electrolyte leakage. The regulation of oxidative pathways through ABA priming was apparent as the plants showed increased activity of enzymes such as peroxidases, catalases, and those involved in glutathione metabolism, including glutathione reductase and glutathione S-transferase. The study also discussed how ABA metabolism regulates sensitivity to 2, 4-D and highlighted certain parameters for selecting redox homeostasis against herbicidal toxicity

Regulation of NADP-Malic Enzyme Activity in Maize (<i>Zea mays</i> L.) under Salinity with Reference to Light and Darkness

We revealed the functional characterization of C4-NADP-malic enzyme (NADP-ME), extracted and partially purified from maize (Zea mays L. cv. Kaveri 50). The leaf discs were previously activated under 1000–1200 µE m−2 s−1, incubated in bicarbonate (2.0 mM) solution, and subjected to salt stress (100 mM NaCl). Initially, salt stress was evident from the accumulations of proline, chlorophyll content, carbohydrate profile, and Hill activity influencing the C4 enzyme. Primarily, in illuminated tissues, the activity of the enzyme recorded a reduced trend through salinity irrespective of light and darkness compared to the control. On illumination, the kinetic parameters such as Vmax of the enzyme increased by 1.36-fold compared to in the dark under salinity whereas Km was decreased by 20% under the same condition. The extent of light induction was proportionate to limiting (0.01 mM) and saturated (4.0 mM) malate concentrations for enzyme activity. Moreover, the catalytic properties of the enzyme were also tested on concomitant responses to activator (citrate and succinate) and inhibitor (oxalate and pyruvate) residues. The sensitivity to light and dark effects was also tested for reducing agents such as dithiothreitol, suggesting the effect of the changes in redox on the regulatory properties of the enzyme. The ratio of enzyme activity under light and darkness in the presence or absence of a reducing agent was concomitantly increased with varying malate concentrations. At the molecular level, protein polymorphism of the enzyme represented minor variations in band intensities, however, not in numbers through salinity subjected to light and darkness. Therefore, salinity-induced changes in the decarboxylation reaction, evident by NADP-ME activity, may be based on the redox property of regulatory sites and sensitivity to light and darkness