Physiological Potential Research Articles

An extracellular scaffolding complex confers unusual rectification upon an ionotropic acetylcholine receptor in C. elegans

Biophysical properties of ligand-gated receptors can be profoundly modified by auxiliary subunits or by the lipid microenvironment of the membrane. Hence, it is sometimes challenging to relate the properties of receptors reconstituted in heterologous expression systems to those of their native counterparts. Here we show that the properties of Caenorhabditis elegans levamisole-sensitive acetylcholine receptors (L-AChRs), the ionotropic acetylcholine receptors targeted by the cholinergic anthelmintic levamisole at neuromuscular junctions, can be profoundly modified by their clustering machinery. We uncovered that L-AChRs exhibit a strong outward rectification invivo, which was not previously described in heterologous systems. This unusual feature for an ionotropic AChR is abolished by disrupting the interaction of the receptors with the extracellular complex required for their synaptic clustering. When recorded at -60 mV, levamisole-induced currents are similar in the wild type and in L-AChR-clustering-defective mutants, while they are halved in these mutants at more depolarized physiological membrane potentials. Consequently, levamisole causes a strong muscle depolarization in the wild type, which leads to complete inactivation of the voltage-gated calcium channels and to an irreversible flaccid paralysis. In mutants defective for L-AChR clustering, the levamisole-induced depolarization is weaker, allowing voltage-gated calcium channels to remain partially active, which eventually leads to adaptation and survival of the worms. This explains why historical screens for C. elegans mutants resistant to levamisole identified the components of the L-AChR clustering machinery, in addition to proteins required for receptor biosynthesis or efficacy. This work further emphasizes the importance of pursuing ligand-gated channel characterization in their native environment.

Validating the physiological potential of zero monopodial compact cotton TCH 1819 culture by chemical manipulation

Cotton is the most important global cash crop which controls economy of many nations. Global sustainability of cotton yield is one of the major challenges for meeting impending threats under climate change. Though India is one among the leading countries in cotton production, the supply is not enough considering the increasing demand. Scientists across the Globe are indulged in developing new lines and cultures with capacity to produce more yields. In this context, here, we have made an attempt to study the growth, physiology, and yield traits of cotton culture - TCH 1819 before its release (now released in the name of CO 17) by different chemical treatments. Observation on the leaf gas exchange traits, leaf parenchymal cells distinguished the source sink relationship of the culture. Chemical manipulation by growth retardants reduced the gibberellins content and modified the foliage structure. By characterizing the physiological potential through manipulation by growth retardant (Mepiquat chloride (0.015 %)) increased the yield by 30%. The traits identified in this study are potential indicators in breeding programme before releasing the variety.

How do Cr and Zn modify cucumber plant re-establishment after grafting?

Plant grafting is a propagation technique that uses two plant individuals to optimize crop production. Although physiological traits defining the growth of grafted plants have been investigated, physiological changes caused by excessive metal nutrients or non-essential metals during the early stages of grafting have been poorly characterized. Understanding such changes would contribute to the selection of rootstocks and scions more tolerant to environmental contamination with heavy metals. Our study evaluated the responses of cucumber plants (Cucumis sativus L.) grafted onto pumpkin rootstocks (Duchesne x Cucurbita moschata Duch.); and exposed to root applications of fertigation solutions with varying concentrations of zinc (10 µM [low] or 2.44 mM [excessive]), chromium (30 µM Cr [low] or 100 µM Cr [excessive]) or both metals (30 µM Cr and 10 µM Zn). Grafted plants exposed to Cr and excess Zn increased enzyme ascorbate peroxidase activity. Plants exposed to Cr exhibited lower magnesium and manganese concentrations in leaves than both the control and Zn treatments, which were associated to low carbon assimilation. On the other hand, low Zn availability improved plant growth after grafting and superoxide dismutase in stems. We verified that the heavy metals Cr and Zn did not impair cucumber plant re-establishment immediately after grafting onto pumpkin rootstock. Our study demonstrated that grafted cucumber plants can grow in environments contaminated with Cr, but will not express their complete physiological potential.

Correction: Ejaz et al. The Use of Soil Conditioners to Ensure a Sustainable Wheat Yield under Water Deficit Conditions by Enhancing the Physiological and Antioxidant Potentials. Land 2022, 11, 368

In the published publication [...]

The ongoing need for rates: can physiology and omics come together to co-design the measurements needed to understand complex ocean biogeochemistry?

The necessity to understand the influence of global ocean change on biota has exposed wide-ranging gaps in our knowledge of the fundamental principles that underpin marine life. Concurrently, physiological research has stagnated, in part driven by the advent and rapid evolution of molecular biological techniques, such that they now influence all lines of enquiry in biological oceanography. This dominance has led to an implicit assumption that physiology is outmoded, and advocacy that ecological and biogeochemical models can be directly informed by omics. However, the main modeling currencies are biological rates and biogeochemical fluxes. Here, we ask: how do we translate the wealth of information on physiological potential from omics-based studies to quantifiable physiological rates and, ultimately, to biogeochemical fluxes? Based on the trajectory of the state-of-the-art in biomedical sciences, along with case-studies from ocean sciences, we conclude that it is unlikely that omics can provide such rates in the coming decade. Thus, while physiological rates will continue to be central to providing projections of global change biology, we must revisit the metrics we rely upon. We advocate for the co-design of a new generation of rate measurements that better link the benefits of omics and physiology.

Effect of Pre-sowing Seed Treatments on Physiological Potential of Seed Germination in Okra

Aims: The present investigation was carried out at SKUAST-Kashmir during the year 2020 to improve the seed vigour and germination potential of okra through pre-sowing seed treatments.
 Study Design: The experiment was laid in completely randomized design (CRD) with three replications
 Place and Duration of Study: The present investigation was carried out at the division of Basic Sciences and Humanities, SKUAST-Kashmir during the year 2020
 Methodology: There were nine pre-sowing seed treatments comprised of simple seed soaking and seed priming with water (T1 and T5), -1.0MPa solution of PEG (T2 and T6), 100ppm solution of GA3 (T3 and T7) and 1.5% solution of KH2PO4 (T4 and T8), respectively along with untreated control (T0). Fifty seeds of each treatment were cultured in 14.0cm Petri dishes lined with 10 layers of moist filter paper. Observations on various germination parameters were recorded at (25±2°C).
 Results: Findings of the study revealed that seed soaking in water (T1) resulted in maximum FGP (93.3%) and GI (16.29) compared to other treatments. Discrete middling of different soaking (AvS) and priming (AvP) treatments indicated the novelty of seed priming over simple soaking. However, unlike FGP and GI, all other parameters viz., CVG, MGT, MGR, T50 and Z-index were found superior when seeds were primed in water (T5) with their recorded values of 87.34%day-1, 1.15day-1, 0.614 day-1, 1.18 day, 0.790, respectively. Values of CVG, MGR and Z index with respect to separate means of simple seed soaking, AvS (69.5%day-1, 0. 0.566day-1 and 0.53) and priming, AvP (75.6%day-1, 0.573day-1 and 0.63) further confirmed the dominancy of seed priming technique over simple seed soaking. Pearson correlation coefficient analysis revealed strong relationship between different quantities of seed germination attributes.
 Conclusion: Seed priming resulted in better germination attributes in okra compared to tradirional seed soaking and as such priming treatments should be practiced instead of traditional seed soaking in okra.

BIOMETRIA DE SEMENTES DE MULUNGU DE DIFERENTES PLANTAS MATRIZES DO SEMIÁRIDO PARAIBANO

ABSTRACT Erythrina velutina Willd. (Fabaceae) is drought tolerant and has the potential for reforestation in the semi-arid region. The response of its seeds to the environmental conditions of each production area influences their size, weight, physiological potential, and health. Thus, this study aimed to assess how the environmental conditions of the different regions of Paraíba influence the biometric characteristics of E. velutina seeds. Seeds from 19 mother plants collected in Juru, Sumé, Araçagi, Guarabira, São João do Cariri, Esperança, Queimadas, Cuité, Boa Vista, and Areia, in the state of Paraíba, Brazil, were used in this study. Water content, thousand-seed weight, and biometric characteristics (length, width, and thickness) were determined in the seeds from each location. The water content ranged from 3.11 to 6.84%, while the thousand-seed weight was higher in mother plants grown in Sumé and Cuité. Seed length ranged from 9.00 to 16.84 mm, being higher in mother plants grown in Juru. Seed thickness and width ranged from 5 to 12.99 mm and were larger in mother plants from Cuité. Temperature, humidity, solar radiation, wind, and precipitation caused variations in the length, width, and thickness of E. velutina seeds, with higher means observed in mother plants grown in Cuité.

Relationship of Fitness Combine Results and National Hockey League Performance: A 25-Year Analysis.

Along with past performance, professional teams consider physical fitness and physiological potential in determining the value of prospective draft picks. The National Hockey League (NHL) Combine fitness results have been examined for their ability to predict draft order, but not bona fide hockey performance. Therefore, we sought to identify the relationships of combine fitness test results to short- and long-term NHL performance. During NHL Combine fitness testing (1994-2007), a standardized battery of tests was conducted. Player performance (1995-2020) was quantified using career cumulative points, time on ice, transitional period to playing in the NHL, and NHL career length. Forward and defensive positions were considered separately. Goalies were not considered. Stepwise linear regression analysis was used to identify fitness variables that predict NHL success. Overall models ranged in their predictive ability from 2% to 16%. The transitional period was predicted by peak leg power and aerobic capacity (V˙O2max; forwards, R2 = .03, and defense, R2 = .06, both P < .01). Points and time on ice within seasons 1 to 3 were predicted by peak leg power and V˙O2max for forwards and defense (R2 = .02-.09, P < .01). Among players accumulating 10 NHL seasons, cumulative points were inversely related to upper-body push-strength-related variables in forwards (R2 = .11) and defense (R2 = .16; both P < .01). The NHL Combine fitness testing offers meaningful data that can inform the likelihood of future success. Peak leg power and V˙O2max predict league entry and early career success. Counterintuitively, upper-body strength is inversely related to long-term performance, which may offer insight into recruitment strategies, player development, or differential team roles.

Viability and vigor of Moringa oleifera Lam. seeds using the tetrazolium test

To evaluate the physiological potential of the seeds, the tetrazolium test would be an interesting alternative, as it is a quick test that provides a detailed analysis of viability and vigor. Therefore, it is necessary to define pre-conditioning conditions, such as temperature and duration of soaking, concentration of the tetrazolium solution, and method of exposing the seeds to staining. Moringa oleifera Lam., belonging to the family Moringaceae, is widely distributed in tropical countries and easily adapted to semi-arid conditions, possessing medicinal value, as forage, condiment, in the cosmetics industry, melliferous, fuel, and in water purification treatment through the coagulant solution made from seeds. Based on the above, the objectives of the present work were to establish the most appropriate procedure for conducting the tetrazolium test to evaluate the viability and vigor of M. oleifera seeds. Only the cotyledons containing the embryo were placed in 50 mL plastic cups and immersed in a solution of 2,3,5-triphenyl chloride tetrazolium salt at concentrations of 0.05; 0.075 and 0.1% for staining periods of 1, 2, and 3 hours in a Biochemical Oxygen Demand chamber at 30 ºC in the dark. The seeds were evaluated one by one for tissue condition (firm or flaccid) and seed color, and by the location and size of the lesions on the cotyledon and embryonic axis. For the standardization of the tetrazolium test, the Completely Randomized Design was used in a 3x3+1 factorial scheme (three concentrations of tetrazolium solution x three staining periods + control = germination test) with four repetitions of 25 seeds. M. oleifera seeds were found to have a high germination rate (100%), there was no significant difference between the control and the percentage of viable seeds (TZ) for the 2 and 3 hours staining periods, immersed in tetrazolium solution at concentrations of 0.075 (96%) and 0.05% (99%), respectively. The most appropriate procedure for conducting the tetrazolium test to assess the viability and vigor of M. oleifera seeds is to use a concentration of 0.05% for 3 hours of salt immersion

Assessing the pathogenicity of gut bacteria associated with tobacco caterpillar Spodoptera litura (Fab.)

The symbiotic relationship between insects and gut microbes contributes to their fitness by serving immense range of functions viz. nutrition and digestion, detoxification, communication and reproduction etc. However, this relationship between insect and gut microbes varies from mutualistic to pathogenic. Gut microbes become pathogenic when the healthy normal microbial composition is perturbed leading to the death of insect host. Spodoptera litura (Fab.) is a polyphagous pest that causes significant damage to many agricultural crops. The management of this pest primarily depends upon chemical insecticides which have resulted in development of resistance. Thus in search for alternative strategies, culturable gut bacteria isolated from S. litura were screened for insecticidal potential. Among these Serratia marcescens and Enterococcus mundtii induced higher larval mortality in S. litura. The mortality rate increased from 32 to 58% due to S. marcescens at concentrations ranging from 2.6 × 108 to 5.2 × 109 cfu/ml and 26 to 52% in case of E. mundtii due to increase in concentration from 4.6 × 108 to 6.1 × 109 cfu/ml. Both the bacteria negatively affected the development, nutritional physiology and reproductive potential of insect. The results indicated a change in gut microbial composition as well as damage to the gut epithelial membrane. Invasion of gut bacteria into the haemocoel led to septicaemia and ultimately death of host insect. In conclusion both these gut bacteria may serve as potential biocontrol agents against S. litura.

Handling the heat: Changes in the heart rate of two congeneric blue mussel species and their hybrids in response to water temperature

In this study we compared some aspects of the physiology of the invasive blue mussel species Mytilus trossulus and the native Mytilus edulis in the White Sea. We registered the heart activity of M. edulis, M. trossulus and the hybrids in situ for two years and tested their thermal tolerance in a laboratory experiment. In situ monitoring showed that the heart rate, as well as its variability, was greater in the invasive species and the hybrids than in the native mussel species. At the same time, the native species showed a higher thermal tolerance in the laboratory experiment. Our results suggest that, when it comes to adaptation to increased temperature, M. edulis has a greater physiological potential than M. trossulus. In a warming climate, the invasive species may lose in competition with the native one due to a higher level of metabolism.

Image analysis for the evaluation of soybean seeds vigor

The search for time and human subjectivity reduction in the analysis of the physiologic potential of seeds has brought forward the use of computerized systems as an alternative. The goal of this research was to assess the effectiveness of the GroundEye equipment in the characterization of soybean seeds vigor by using the image analysis technique in comparison to the information provided by vigor tests recommended to soybean seeds. Sixteen lots of two soybean varieties were used — variety 98Y12 and P98Y70, characterized by the following tests: germination test, accelerated ageing test, cold test, tetrazolium test, and seedling emergence in the field. The image analysis was performed using the GroundEye software to obtain the vigor index and the average length of seedlings and roots for a later comparison with the results of the accelerated ageing test and the manual measurement of the average length of seedlings and roots. GroundEye has demonstrated efficiency in the determination of vigor of soybean seeds and has reduced the time needed to obtain the results in six days, being indicated in the quality control programs established by soybean seeds production companies.

ATP synthesis in an ancient ATP synthase at low driving forces

Hyperthermophilic archaea are close to the origin of life. Some hyperthermophilic anaerobic archaea live under strong energy limitation and have to make a living near thermodynamic equilibrium. Obviously, this requires adaptations of the energy-conserving machinery to harness small energy increments. Their ATP synthases often have an unusual motor subunit c that is predicted to prevent ATP synthesis. We have purified and reconstituted into liposomes such an archaeal ATP synthase found in a mesophilic bacterium. The enzyme indeed synthesized ATP at physiological membrane potentials, despite its unusual c subunit, but the minimal driving force for ATP synthesis was found to be even lower than in ATP synthases with usual c subunits. These data not only reveal an intermediate in the transition from ATP hydrolases to ATP synthases but also give a rationale for a bioenergetic adaptation of microbial growth near the thermodynamic equilibrium.

Preself-Feeding Medaka Fry Provides a Suitable Screening System for in Vivo Assessment of Thyroid Hormone-Disrupting Potential.

Endocrine-disrupting chemicals are assessed based on their physiological potential and their potential associated adverse effects. However, suitable end points for detection of chemicals that interfere with the thyroid hormone (TH) system have not been established in nonmammals, with the exception of amphibian metamorphosis. The aims of the current study were to develop an in vivo screening system using preself-feeding medaka fry (Oryzias latipes) for the detection of TH-disrupting chemicals and elucidate the underlying molecular mechanism. 17α-Ethinylestradiol (EE2: <100 ng/L) did not induce mRNA expression of estrogen-responsive genes, vitellogenins (vtgs) mRNA. Meanwhile, coexposure with thyroxin (T4) induced an increase of vtg expression. TH-disrupting chemicals (thiourea (TU), perfluorooctanoic acid (PFOA), and tetrabromobisphenol A (TBBPA)) significantly suppressed EE2 (1,000 ng/L)-induced vtg1 expression, while T4 rescued their expression as well as that of thyroid hormone receptor α (tRα) and estrogen receptors (esrs). These results were supported by in silico analysis of the 5'-transcriptional regulatory region of these genes. Furthermore, the esr1 null mutant revealed that EE2-induced vtg1 expression requires mainly esr2a and esr2b in a TH-dependent manner in preself-feeding fry. Application of preself-feeding medaka fry as a screening system might help decipher the in vivo mechanisms of action of TH-disrupting molecules, while providing an alternative to the traditional animal model.

Inhibition of human recombinant T-type calcium channels by phytocannabinoids in vitro.

T-type Ca channels (ICa ) regulate neuronal excitability and contribute to neurotransmitter release. The phytocannabinoids Δ9 -tetrahydrocannabinol and cannabidiol effectively modulate T-type ICa , but effects of other biologically active phytocannabinoids on these channels are unknown. We thus investigated the modulation of T-type ICa by low abundance phytocannabinoids. A fluorometric (fluorescence imaging plate reader [FLIPR]) assay was used to investigate modulation of human T-type ICa (CaV 3.1, 3.2 and 3.3) stably expressed in FlpIn-TREx HEK293 cells. The biophysical effects of some compounds were examined using whole-cell patch clamp recordings. In the FLIPR assay, all 11 phytocannabinoids tested modulated T-type ICa , with most inhibiting CaV 3.1 and CaV 3.2 more effectively than CaV 3.3. Cannabigerolic acid was the most potent inhibitor of CaV 3.1 (pIC50 6.1±0.6) and CaV 3.2 (pIC50 6.4±0.4); in all cases, phytocannabinoid acids were more potent than their corresponding neutral forms. In patch clamp recordings, cannabigerolic acid inhibited CaV 3.1 and 3.2 with similar potency to the FLIPR assay; the inhibition was associated with significant hyperpolarizing shift in activation and steady-state inactivation of these channels. In contrast, cannabidiol, cannabidivarin, and cannabigerol only affected channel inactivation. Modulation of T-type calcium channels is a common property of phytocannabinoids, which all increase steady-state inactivation at physiological membrane potentials, with some also affecting channel activation. Thus, T-type ICa may be a common site of action for phytocannabinoids, and the diverse actions of phytocannabinoids on channel gating may provide insight into structural requirement for selective T-type ICa modulators.

Microcurrent Frequencies’ Effect on the Cell Membrane Potential

Research shows that cellular and mitochondrial (ΔΨm) membrane potentials are strong indicators of cellular physiology. In this paper we review further research suggesting that microcurrent frequencies can positively influence both these membrane potentials. The goal of this research is to show how microcurrent might stimulate physiological potentials in order to support a healthy function of bioelectric fields of cells and organs. In the second part of the article, a study to examine the effects of microcurrent application on the body's response to electric measurements is presented, in particular to a change in voltage-current lag known as a phase angle. The test involved measuring bioimpedance of a person before and after a 30-minute application with microcurrent stimulation. Fifteen healthy subjects were examined through impedance measurements taken on one arm. The results showed a consistent increase in phase angle directly after the stimulation, confirming a widely accepted indication of health improvement on a cellular level. These results are encouraging and justify further investigations on the effect of microcurrent stimulation on the human body in relation to general cellular health and regenerative functions.

Initial development and physiological potential of soybean and maize as a function of vigor level and seed size

This work aimed to evaluate the initial development of soybean and maize plants due to the vigor level and the seed size used. Soybean seeds of cultivar 5855 RSF IPRO (BMX ELITE) and hybrid maize Fórmula Viptera were classified in two sizes of sieve (6.00 and 6.50 mm - soybean; 7.50 and 7.00 mm - maize) and two levels of vigor for soybean and three levels of vigor for maize. The experimental design was completely randomized in a 2 x 2 bifactorial scheme (sieve size x vigor levels) for soybean and 2 x 3 (sieve size x vigor levels) for maize, with four replications. The variables evaluated were germination, first germination count and emergence in bed. In the evaluation of seedling initial performance, shoot, root and total length, volume and dry mass were evaluated at 7, 11 and 14 days after sowing for soybean and at 7, 14 and 21 days for maize seeds. High vigor soybean and maize seeds presented high physiological quality, as well as in the development of plants, where larger and of high vigor soybean seeds showed higher plant length and dry mass. The classification of seeds through the level of vigor influences the physiological quality of soybean and maize seeds. Larger seeds with higher vigor showed greater length and initial development of seedlings, being indicated the use of seeds of something vigor

Industrial treatment of soybean seeds subjected to high volumes of fungicides, insecticides, biostimulants and micronutrients during storage

The objective of this study was to examine the performance of soybean seeds at different storage periods as well as their physiological quality after the application of spray mixtures of insecticides, fungicides, polymers, micronutrients and biostimulants. The experiment was laid out in a completely randomized design with four replicates. Treatments were as follows: T1 - untreated seeds (control); T2 - insecticide and fungicide + polymer + drying powder; T3 - insecticide and fungicide + polymer + drying powder + micronutrient; and T4 - insecticide and fungicide + polymer + drying powder + micronutrient + biostimulant. For each industrial seed treatment (IST), the specific spray volumes tested were 0, 400, 600 or 1100 mL 100 kg seeds-1. Soybean seeds were stored for 0, 15, 30, 45, 60 and 90 days and subsequently evaluated for physiological potential. At each storage period, the following tests were conducted: germination, first count, accelerated aging, emergence speed index, final emergence in sand substrate, whole-seedling length, shoot length and root length. Industrial seed treatment reduces seed physiological quality. The seed treatment corresponding to the highest spray volume provided the lowest means in all tested treatments. For all analyzed variables, the ST4 treatment, to which biostimulant was added, presented the lowest averages, indicating that the greater the volume of spray, the greater the damage caused to the physiological quality of the seeds, both before and after storage

Evaluation of the physiological potential of Panicum maximum seeds by multivariate analysis

The aim of this work was to identify efficient vigor tests for differentiating the seed lots, forecasting seedling emergence in the field and assessing the physiological quality of Panicum maximum seeds. 12 seed lots from the cultivar Tanzania and 11 seed lots from the cultivar Massai were evaluated for water content, germination, first count and germination speed index, emergence and first emergence count of seedlings in sand, root length and shoot length, analysis of SVIS® images (seedling length, vigor and uniformity index) and seedling emergence in the field. The work was conducted in a completely randomized design for tests performed in the laboratory and in randomized blocks for tests in the field. The data were subjected to analysis of variance and the means compared by Scott Knott's test at 5% probability and statistical multivariate clustering analysis and principal components analysis. The shoot and root length tests are efficient for the evaluation of the physiological potential of P. maximum cv. Massai, while the seedling length, vigor index and growth uniformity index tests using image analysis, seedling emergence in sand and first seedling emergence count in sand are efficient in assessing the physiological potential of seeds of P. maximum cv. Tanzania, and providing information similar to that of seedling emergence in the field.

Spectral characterisation of ventricular intracardiac potentials in human post-ischaemic bipolar electrograms

Abnormal ventricular potentials (AVPs) are frequently referred to as high-frequency deflections in intracardiac electrograms (EGMs). However, no scientific study performed a deep spectral characterisation of AVPs and physiological potentials in real bipolar intracardiac recordings across the entire frequency range imposed by their sampling frequency. In this work, the power contributions of post-ischaemic physiological potentials and AVPs, along with some spectral features, were evaluated in the frequency domain and then statistically compared to highlight specific spectral signatures for these signals. To this end, 450 bipolar EGMs from seven patients affected by post-ischaemic ventricular tachycardia were retrospectively annotated by an experienced cardiologist. Given the high variability of the morphologies observed, three different sub-classes of AVPs and two sub-categories of post-ischaemic physiological potentials were considered. All signals were acquired by the CARTO® 3 system during substrate-guided catheter ablation procedures. Our findings indicated that the main frequency contributions of physiological and pathological post-ischaemic EGMs are found below 320 Hz. Statistical analyses showed that, when biases due to the signal amplitude influence are eliminated, not only physiological potentials show greater contributions below 20 Hz whereas AVPs demonstrate higher spectral contributions above ~ 40 Hz, but several finer differences may be observed between the different AVP types.