Mitochondria play a key role in cellular signalling, metabolism and energetics. Proper architecture and remodelling of the inner mitochondrial membrane are essential for efficient respiration, ...apoptosis and quality control in the cell. Several protein complexes including mitochondrial contact site and cristae organizing system (MICOS), F1FO‐ATP synthase, and Optic Atrophy 1 (OPA1), facilitate formation, maintenance and stability of cristae membranes. MICOS, the F1FO‐ATP synthase, OPA1 and inner membrane phospholipids such as cardiolipin and phosphatidylethanolamine interact with each other to organize the inner membrane ultra‐structure and remodel cristae in response to the cell's demands. Functional alterations in these proteins or in the biosynthesis pathway of cardiolipin and phosphatidylethanolamine result in an aberrant inner membrane architecture and impair mitochondrial function. Mitochondrial dysfunction and abnormalities hallmark several human conditions and diseases including neurodegeneration, cardiomyopathies and diabetes mellitus. Yet, they have long been regarded as secondary pathological effects. This review discusses emerging evidence of a direct relationship between protein‐ and lipid‐dependent regulation of the inner mitochondrial membrane morphology and diseases such as fatal encephalopathy, Leigh syndrome, Parkinson's disease, and cancer.
It is widely known that cobalt (Co) stress adversely affects plant growth and biomass accumulation, posing serious threats to crop production and food security. Nanotechnology is an emerging field in ...crop sciences for its potential in improving crop production and mitigating various stresses. Although there have been several studies reporting the toxic effects of zinc oxide nanoparticles (ZnO NPs) on different crops, their role in ameliorating heavy metal toxicity are still poorly understood. This study aimed to investigate the beneficial effects of seed priming with ZnO NPs in mitigating the phytotoxicity induced by Co stress. Our results demonstrated that ZnO NPs significantly improved the plant growth, biomass, and photosynthetic machinery in maize under Co stress. The NPs priming reduced ROS and MDA accumulations in maize shoots. More importantly, ZnO NPs alleviated the toxic effects of Co by decreasing its uptake and conferred stability to plant ultra-cellular structures and photosynthetic apparatus. Furthermore, a higher accumulation of nutrient content and antioxidant enzymes were found in NPs-primed seedlings. Collectively, we provide first evidence to demonstrate the alleviation of Co toxicity via ZnO NPs seed priming in maize, thus, illustrating the potential role of ZnO NPs to be applied as a stress mitigation agent for the crops grown in Co contaminated areas to enhance crop growth and yield.
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•ZnO NPs localized in seed labeled with Zinpyr-1 under confocal microscopy.•ZnO NPs increased seed zinc contents and enhanced nutrient uptake under Co stress.•ZnO NPs reduced oxidative damage and improved plant antioxidant defense system.•ZnO NPs improved plant photosynthetic efficiency and biomass accumulation.•ZnO NPs protected stomatal and ultra-cellular structure of plant under Co stress.
Precise identification of exotic whiteflies is a prerequisite to curb the invasive potential on to a new geographical location and to evolve effective management strategies. Conventionally, whitefly ...taxonomy is based on the description of the fourth‐instar nymph or puparium, however, in the current investigation egg to adult morphology along with morphometrics of rugose spiraling whitefly (RSW), Aleurodicus rugioperculatus Martin was critically analyzed and various morphological characteristics were illustrated. The morphometric analysis revealed that in the immature life stages of the pest, the length: width ratio decreased with each successive life stage, such as the egg, first, second, third, and fourth instar (2.472 ± 0.071, 1.913 ± 0.020, 1.550 ± 0.045, 1.297 ± 0.034, and 1.174 ± 0.058 mm), respectively. Across different nymphal instars, the shape of lingula was greatly modified from tongue‐like to triangle‐shaped. The number and distribution of compound pores also vary among the different nymphal stages. The ultra‐structures of the antenna through electron‐microscopy depicted finer details of sensory cones. The modulation in the shape and the structural arrangement of microtrichia on the plate was illustrated. The study indicated accurate diagnosis of various stages of RSW for effective interception of goods at quarantine stations and thus preventing the entry of exotic pests into the country.
Research Highlights
Microscopy‐based (light and scanning electron microscopy) morphological characterization of rugose spiraling whitefly, (Aleurodicus rugioperculatus Martin).
Arsenic (As) assessment in agricultural soils and corresponding crops is necessary from the global health safety perspective. To the best of our knowledge, we are reporting for the first time, As ...flux determining parametric equations for paddy field with seasonal rice cultivation under conventional flooding and dry-wet irrigation approaches. Rigorous field experiments and measuring quantitative parameters, flushed out or percolated into the deeper soil As flux was assessed. A wintery (boro)-monsoonal (aman) study from 2016 to 2019 has been conducted showing the efficiency of dry-wet irrigation on reduction of soil As bioavailability. The reduction in boro was 52.4% in 2016 to 64.8% in 2019 while in aman, it was 61% in 2016 to 74.9% in 2019. Low bioavailability was correlated to plant’s internal vascular structure that was found more rigid and firm in dry-wet field grown plants. Observed soil physico-chemical parameters clearly influenced As bioavailability as well as soil microbial community. Assessment of microbial diversity using metagenomics under altered water regime was done by population analysis, relative abundance, species richness, Krona chart comparison. Dry-wet field was found to be more diverse and enriched in microbial community than that of the flooded soil indicating an affective reduction of As bioavailability under biotic-abiotic factors.
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•Dry-wet irrigation in rice cultivation reduces arsenic bioavailability efficiently.•Novel parametric equations measured higher soil arsenic flux content in monsoon.•Arsenic bioavailability to rice plants is justified by plant accumulation index.•Dry-wet irrigation enhances plant’s internal ultra-structure than flooded plants.•Soil microbial diversity are influenced and thrived under dry-wet field conditions.
•Fruit cracking is a major physiological disorder of lemon and lime.•Light microscopy and scanning electron microscopy of healthy and cracked peel and pedicel was performed.•The cracked fruit peels ...were coarser and thinner with empty oil glands as compared to healthy cracked fruit peel.•The xylem of cracked fruit pedicel was disorganized resulting in disruption of water and mineral flow to the fruit causing cracking.
Fruit cracking is a major physiological disorder of lemon and limits the productivity of this fruit. The present study was conducted to compare the structural variation in peel and pedicel of healthy and cracked fruits of lemon. Sections of healthy and cracked fruit peel, stem end and pedicel were analyzed by light microscope and scanning electron microscopy (SEM). The ultra-structure of peel of healthy and cracked lemons showed significant difference in peel thickness, epidermal thickness, arrangement of oil glands and vascular tissues. The pedicel of cracked fruit exhibited collapsed and deformed xylem tissues. Ruptured oil gland pits, rough surface and reduced peel thickness was observed through SEM in cracked fruits as compared to healthy fruits. The coarse thinner peels with smaller epidermal thickness and larger empty oil glands are prone to fruit cracking as compared to smooth peels of healthy fruits. The xylem tissue in cracked fruit pedicel was disorganized that disrupts the water and mineral flow to the growing fruit. The disorganization of xylem tissue may be due to irregularity in water transport followed by pulp expanding resulting in thinner peels leading to fruit cracking.
New It is a new finding that fruit cracking in lemon is possibly due to irregularity in influx of water that creates tension in xylem vessels. This results in disorganization of vascular tissues of pedicel, which disrupts the regular transport of water and nutrient to developing albedo and flavedo and cause fruit cracking.
The microsporidium Nosema neumanni n. sp., a new parasite of the honeybee Apis mellifera is described based on its ultra-structural and molecular characteristics. Structures resembling microsporidian ...spores were found by microscopic examination of honeybees from Uganda. Molecular confirmation failed when PCR primers specific for Nosema apis and Nosema ceranae were used, but was successful with primers covering the whole family of Nosematidae. We performed transmission electron microscopy and found typical microsporidian spores which were smaller (length: 2.36±0.14μm and width: 1.78±0.06μm; n=6) and had fewer polar filament coils (10–12) when compared to those of known species infecting honeybees. The entire 16S SSU rRNA region was amplified, cloned and sequenced and was found to be unique with the highest resemblance (97% identity) to N. apis. The incidence of N. neumanni n. sp. in Ugandan honeybees was found to be much higher than of the two other Nosema species.
Cultured cells are dramatically affected by the micro‐environment in which they are grown. In this study, we have investigated whether HepG2 liver cells grown in three dimensional (3‐D) cultures cope ...more effectively with the known cytotoxic agent, methotrexate, than their counterparts grown on traditional two dimensional (2‐D) flat plastic surfaces. To enable 3‐D growth of HepG2 cells in vitro, we cultured cells on 3‐D porous polystyrene scaffolds previously developed in our laboratories. HepG2 cells grown in 3‐D displayed excellent morphological characteristics and formed numerous bile canaliculi that were seldom seen in cultures grown on 2‐D surfaces. The function of liver cells grown on 3‐D supports was significantly enhanced compared to activity of cells grown on 2‐D standard plasticware. Unlike their 2‐D counterparts, 3‐D cultures were less susceptible to lower concentrations of methotrexate. Cells grown in 3‐D maintained their structural integrity, possessed greater viability, were less susceptible to cell death at higher levels of the cytotoxin compared to 2‐D cultures, and appeared to respond to the drug in a manner more comparable to its known activity in vivo. Our results suggest that hepatotoxicity testing using 3‐D cultures might be more likely to reflect true physiological responses to cytotoxic compounds than existing models that rely on 2‐D culture systems. This technology has potential applications for toxicity testing and drug screening.
Corneal collagen cross-linking (CXL) is a treatment that is widely applied to halt the progression of ectatic diseases such as keratoconus by creating biomechanical strength in the cornea. Most of ...the studies assessed the effect of the CXL on the cornea without any differentiation of its effect between periphery and the center of the untreated control cornea especially after the 7 days of CXL application. We investigate the ultrastructural changes in the architecture of the center and periphery of rat corneas, 7 days after standard CXL application. Five Wistar rats (10 corneas) were used in the present study. The left eye corneas (5 mm area) were de-epithelialized and irradiated with standard CXL application using riboflavin and Ultraviolet-A (UVA) (3 mW/cm2 for 30 min). The right eye corneas were used as a control. The sclera-cornea button was removed and processed for electron microscopy. Digital images were captured with a bottom mounted Quemesa camera and analyzed using the iTEM software. The ultrastructure of epithelium, hemi-desmosomes, Bowman's layer and stroma were organized in both untreated control and CXL rat cornea in both untreated control and CXL rat cornea. Within the same CXL cornea, both the collagen fibril (CF) diameter and interfibrillar spacing at the center were significantly smaller compared to the peripheral diameter and spacing of the cornea. When comparing the untreated control and CXL cornea, the central interfibrillar spacing of the CXL cornea was significantly smaller than the central spacing the untreated control cornea. In the CXL cornea the peripheral spacing was significantly higher compared to the peripheral interfibrillar spacing of the untreated control cornea. Within the CXL cornea, the proteoglycans (PGs) area and density of the periphery was significantly higher compared to the area and density of the center of the cornea. It suggests that CXL was more effective at the periphery of the cornea. This could be due to the higher amount of leucine rich PG lumican and higher diffusion of oxygen and riboflavin at the periphery cornea.
•Collagen fibril diameter was smaller at center than periphery within the same CXL cornea.•Interfibrillar spacing was smaller at center than periphery within the same cornea.•CF diameter of the CXL cornea was smaller than that of the normal cornea.•Interfibrillar spacing of the CXL cornea was smaller than that of the normal cornea.•PGs density was higher in the CXL cornea than that in the normal cornea.
This study investigated the effect of different acute heat stress (HS) levels on chicken meat quality and ultra-structure.
Chickens were randomly divided into 7 groups to receive different HS ...treatments: i) 36°C for 1 h, ii) 36°C for 2 h, iii) 38°C for 1 h, iv) 38°C for 2 h, v) 40°C for 1 h, vi) 40°C for 2 h, and vii) un-stressed control group (25°C). Blood cortisol level, breasts initial temperature, color, pH, water holding capacity (WHC), protein solubility and ultra-structure were analyzed.
HS temperatures had significant effects on breast meat temperature, lightness (L*), redness (a*), cooking loss and protein solubility (p<0.05). The HS at 36°C increased L*24 h value (p<0.01) and increased the cooking loss (p<0.05), but decreased a*24 h value (p<0.05). However, as the temperature increased to 38°C and 40°C, all the values of L*24 h, cooking loss and protein denaturation level decreased, and the differences disappeared compared to control group (p> 0.05). Only the ultimate pH24 h at 40°C decreased compared to the control group (p<0.01). The pH in 36°C group declined greater than other heat-stressed group in the first hour postmortem, which contributed breast muscle protein degeneration combining with high body temperature, and these variations reflected on poor meat quality parameters. The muscle fiber integrity level in group 40°C was much better than those in 36°C with the denatured position mainly focused on the interval of muscle fibers which probably contributes WHC and light reflection.
HS at higher temperature (above 38°C) before slaughter did not always lead to more pale and lower WHC breast meat. Breast meat quality parameters had a regression trend as HS temperature raised from 36°C. The interval of muscle fibers at 24 h postmortem and greater pH decline rate with high body temperature in early postmortem period could be a reasonable explanation for the variation of meat quality parameters.
Myxosporeans are a diverse group of microscopic cnidarians of wide distribution that evolved into a parasitic lifestyle. A new myxosporean species, Myxobolus sp., is herein described infecting the ...mandible of wild specimens of Synbranchus marmoratus, caught in the world's largest tropical wetland area, Pantanal, Brazil. Light, scanning, transmission electron microscopy and histological observations unveiled detailed taxonomic information of the new myxosporean cnidarian. Ultrastructural analysis revealed a detailed description of plasmodia structures which can be used for comparison with plasmodia from other species of myxobolids. Both histological and ultrastructural observations evidenced a connective tissue capsule surrounding the plasmodia of Myxobolus sp. as a histopathological host reaction to the infection of this parasitic cnidarian. Histology showed that tissue tropism of the new myxosporean occurs in a well-defined part of the mandible, with development of plasmodia occurring in the epidermis layer. Mature myxospores from the valvular view featured an ovoid shape and had a short prolongation of the spore valves in the posterior end. Myxospores measured 22.7 ± 1.2 µm (21.5–23.9 µm) in length, 12.5 ± 0.4 µm (12.1–12.9 µm) in width and 11.3 ± 0.5 (10.8–11.8 µm) in thickness. Polar capsules were pyriform equally-sized and measuring 4.6 ± 0.3 µm (3.9–4.3 µm) in length and 2.9 ± 0.1 µm in width (2.8–3.0 µm). Finally, this study substantiates the still hidden myxosporean diversity from South America.
•First report describing infection of Symbranchus marmoratus with myxosporean cnidarian from South America.•A new myxosporean cnidarian is described using detailed features obtained from light, scanning and transmission electron micrcoscopy.•This study provides detailed descriptive ultrastructural features which could suit as a basis for accurate taxonomic identification of this new myxoxporean cnidarian.•Ultrastructural features have been described in detail for plasmodia of the new myxosporean species.
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