Morphology of Four Strains of Phellinoid Agaricomycetes and Microstructural and Physiological Properties of Their Exudates.

To study and compare the morphology of the phellinoid Agaricomycetes strains and find other strategies to improve Phellinus spp. growth and metabolism. In this study, the morphological characteristics of four Phellinus igniarius strains (phellinoid Agaricomycetes) were observed under a light microscope. The exudates from these fungi were observed using light microscopy, scanning electron microscopy (SEM), and energy-dispersive spectrometry (EDS). The exudates were initially transparent with a water-like appearance, and became darker with time at neutral pH. Microscopy of air-dried exudates revealed regular shapes and crystals. Cl- (chloride) and K+ were the two key elements analyzed using EDS. Polyphenol oxidase (POD), catalase (CAT), and laccase activities were detected in mycelia from each of the four Phellinus strains. The K+ content of the three strains was higher than that of the wild strain. Cl- content correlated negatively with that of K+. Laccase activities associated with each mycelia and its corresponding media differed under cold and contaminated conditions.

Canola (Brassica napus) enhances sodium chloride and sodium ion tolerance by maintaining ion homeostasis, higher antioxidant enzyme activity and photosynthetic capacity fluorescence parameters.

Under salt stress, plants are forced to take up and accumulate large amounts of sodium (Na+ ) and chloride (Cl- ). Although most studies have focused on the toxic effects of Na+ on plants, Cl- stress is also very important. This study aimed to clarify physiological mechanisms underpinning growth contrasts in canola varieties with different salt tolerance. In hydroponic experiments, 150mM Na+ , Cl- and NaCl were applied to salt-tolerant and sensitive canola varieties. Both NaCl and Na+ treatments inhibited seedling growth. NaCl caused the strongest damage to both canola varieties, and stress damage was more severe at high concentrations of Na+ than Cl- . High Cl- promoted the uptake of ions (potassium K+ , calcium Ca2+ ) and induced antioxidant defence. Salt-tolerant varieties were able to mitigate ion toxicity by maintaining lower Na+ content in the root system for a short period of time, and elevating magnesium Mg2+ content, Mg2+ /Na+ ratio, and antioxidant enzyme activity to improve photosynthetic capacity. They subsequently re-established new K+ /Na+ and Ca2+ /Na+ balances to improve their salt tolerance. High concentrations of Cl salts caused less damage to seedlings than NaCl and Na salts, and Cl- also had a positive role in inducing oxidative stress and responsive antioxidant defence in the short term.

Differential response of proline metabolism defense, Na+ absorption and deposition to salt stress in salt-tolerant and salt-sensitive rapeseed (Brassica napus L.) genotypes.

Soil salinization is a major abiotic factor threatening rapeseed yields and quality worldwide, yet the adaptive mechanisms underlying salt resistance in rapeseed are not clear. Therefore, this study aimed to explore the differences in growth potential, sodium (Na+) retention in different plant tissues, and transport patterns between salt-tolerant (HY9) and salt-sensitive (XY15) rapeseed genotypes, which cultivated in Hoagland's nutrient solution in either the with or without of 150 mM NaCl stress. The results showed that the inhibition of growth-related parameters of the XY15 genotype was higher than those of the HY9 in response to salt stress. The XY15 had lower photosynthesis, chloroplast disintegration, and pigment content but higher oxidative damage than the HY9. Under NaCl treatment, the proline content in the root of HY9 variety increased by 8.47-fold, surpassing XY15 (5.41-fold). Under salt stress, the HY9 maintained lower Na+ content, while higher K+ content and exhibited a relatively abundant K+/Na+ ratio in root and leaf. HY9 also had lower Na+ absorption, Na+ concentration in xylem sap, and Na+ transfer factor than XY15. Moreover, more Na+ contents were accumulated in the root cell wall of HY9 with higher pectin content and pectin methylesterase (PME) activity than XY15. Collectively, our results showed that salt-tolerant varieties absorbed lower Na+ and retained more Na+ in the root cell wall (carboxyl group in pectin) to avoid leaf salt toxicity and induced higher proline accumulation as a defense and antioxidant system, resulting in higher resistance to salt stress, which provides the theoretical basis for screening salt resistant cultivars.

Bionic Potassium Ion Channel in Live Cells Repairs Cardiomyocyte Function.

The disturbance of potassium current in cardiac myocytes caused by potassium channel dysfunction can lead to cardiac electrophysiological disorders, resulting in associated cardiovascular diseases. The emergence of artificial potassium ion channels opens up a way to replace dysfunctional natural ion channels and cure related diseases. However, bionic potassium ion channels have not been introduced into living cells to regulate cell function. One of the biggest challenges is that when the bionic channel fuses with the cell, it is difficult to control the inserting angle of the bionic potassium channel to ensure its penetration of the entire cell membrane. In nature, the extracellular vesicles can fuse with living cells with a completely preserved structure of vesicle protein. Inspired by this, we developed a vesicle fusion-based bionic porin (VFBP), which integrates bionic potassium ion channels into cardiomyocytes to replace damaged potassium ion channels. Theoretical and experimental results show that the inserted bionic ion channels have a potassium ion transport rate comparable to that of natural ion channels, which can restore the potassium ion outflow in cardiomyocytes and repair the abnormal action potential and excitation-contraction coupling of cardiomyocytes. Therefore, the bionic potassium ion channel system based on membrane fusion is expected to become the research object in many fields such as ultrafast ion transport, transmembrane delivery, and channelopathies treatment.

The Antimicrobial Activity of Human Defensins at Physiological Non-Permeabilizing Concentrations Is Caused by the Inhibition of the Plasma Membrane H+-ATPases.

Human defensins are cysteine-rich peptides (Cys-rich peptides) of the innate immune system. Defensins contain an ancestral structural motif (i.e., γ-core motif) associated with the antimicrobial activity of natural Cys-rich peptides. In this study, low concentrations of human α- and ß-defensins showed microbicidal activity that was not associated with cell membrane permeabilization. The cell death pathway was similar to that previously described for human lactoferrin, also an immunoprotein containing a γ-core motif. The common features were (1) cell death not related to plasma membrane (PM) disruption, (2) the inhibition of microbicidal activity via extracellular potassium, (3) the influence of cellular respiration on microbicidal activity, and (4) the influence of intracellular pH on bactericidal activity. In addition, in yeast, we also observed (1) partial K+-efflux mediated via Tok1p K+-channels, (2) the essential role of mitochondrial ATP synthase in cell death, (3) the increment of intracellular ATP, (4) plasma membrane depolarization, and (5) the inhibition of external acidification mediated via PM Pma1p H+-ATPase. Similar features were also observed with BM2, an antifungal peptide that inhibits Pma1p H+-ATPase, showing that the above coincident characteristics were a consequence of PM H+-ATPase inhibition. These findings suggest, for the first time, that human defensins inhibit PM H+-ATPases at physiological concentrations, and that the subsequent cytosolic acidification is responsible for the in vitro microbicidal activity. This mechanism of action is shared with human lactoferrin and probably other antimicrobial peptides containing γ-core motifs.

Endurance Training Improves Leg Proton Release and Decreases Potassium Release During High-Intensity Exercise in Normoxia and Hypobaric Hypoxia.

AIM: To assess the impact of endurance training on skeletal muscle release of H+ and K+. METHODS: Nine participants performed one-legged knee extension endurance training at moderate and high intensities (70%-85% of Wpeak), three to four sessions·week-1 for 6 weeks. Post-training, the trained and untrained (control) leg performed two-legged knee extension at low, moderate, and high intensities (40%, 62%, and 83% of Wpeak) in normoxia and hypoxia (~4000 m). The legs were exercised simultaneously to ensure identical arterial inflow concentrations of ions and metabolites, and identical power output was controlled by visual feedback. Leg blood flow was measured (ultrasound Doppler), and acid-base variables, lactate- and K+ concentrations were assessed in arterial and femoral venous blood to study K+ and H+ release. Ion transporter abundances were assessed in muscle biopsies. RESULTS: Lactate-dependent H+ release was similar in hypoxia to normoxia (p = 0.168) and was lower in the trained than the control leg at low-moderate intensities (p = 0.060-0.006) but similar during high-intensity exercise. Lactate-independent and total H+ releases were higher in hypoxia (p < 0.05) and increased more with power output in the trained leg (leg-by-power output interactions: p = 0.02). K+ release was similar at low intensity but lower in the trained leg during high-intensity exercise in normoxia (p = 0.024) and hypoxia (p = 0.007). The trained leg had higher abundances of Na+/H+ exchanger 1 (p = 0.047) and Na+/K+ pump subunit α (p = 0.036). CONCLUSION: Moderate- to high-intensity endurance training increases lactate-independent H+ release and reduces K+ release during high-intensity exercise, coinciding with increased Na+/H+ exchanger 1 and Na+/K+ pump subunit α muscle abundances.

Spatiotemporal patterns of leaf nutrients of wild apples in a wild fruit forest plot in the Ili Valley, China.

Malus sieversii, commonly known as wild apples, represents a Tertiary relict plant species and serves as the progenitor of globally cultivated apple varieties. Unfortunately, wild apple populations are facing significant degradation in localized areas due to a myriad of factors. To gain a comprehensive understanding of the nutrient status and spatiotemporal variations of M. sieversii, green leaves were collected in May and July, and the fallen leaves were collected in October. The concentrations of leaf nitrogen (N), phosphorus (P), and potassium (K) were measured, and the stoichiometric ratios as well as nutrient resorption efficiencies were calculated. The study also explored the relative contributions of soil, topographic, and biotic factors to the variation in nutrient traits. The results indicate that as the growing period progressed, the concentrations of N and P in the leaves significantly decreased (P < 0.05), and the concentration of K in October was significantly lower than in May and July. Throughout plant growth, leaf N-P and N-K exhibited hyperallometric relationships, while P-K showed an isometric relationship. Resorption efficiency followed the order of N < P < K (P < 0.05), with all three ratios being less than 1; this indicates that the order of nutrient limitation is K > P > N. The resorption efficiencies were mainly regulated by nutrient concentrations in fallen leaves. A robust spatial dependence was observed in leaf nutrient concentrations during all periods (70.1-97.9% for structural variation), highlighting that structural variation, rather than random factors, dominated the spatial variation. Nutrient resorption efficiencies (NRE, PRE, and KRE) displayed moderate structural variation (30.2-66.8%). The spatial patterns of nutrient traits varied across growth periods, indicating they are influenced by multifactorial elements (in which, soil property showed the highest influence). In conclusion, wild apples manifested differentiated spatiotemporal variability and influencing factors across various leaf nutrient traits. These results provide crucial insights into the spatiotemporal patterns and influencing factors of leaf nutrient traits of M. sieversii at the permanent plot scale for the first time. This work is of great significance for the ecosystem restoration and sustainable management of degrading wild fruit forests.

Control of cyanobacterial growth with potassium; implications for bloom control in nuclear storage ponds.

Microbial blooms have been reported in the First Generation Magnox Storage Pond at the Sellafield Nuclear Facility. The pond is kept alkaline with NaOH to minimise fuel rod corrosion, however alkali-tolerant microbial blooms dominated by the cyanobacterium Pseudanabaena catenata are able to thrive in this hostile environment. This study assessed the impact of alternative alkali-dosing regimens (KOH versus NaOH treatment) on biomass accumulation, using a P. catenata dominated mixed culture, which is representative of the pond environment. Optical density was reduced by 40-67 % with KOH treatment over the 3-month chemostat experiment. Microbial community analysis and proteomics demonstrated that the KOH-dependent inhibition of cell growth was mostly specific to P. catenata. The addition of KOH to nuclear storage ponds may therefore help control growth of this pioneer photosynthetic organism due to its sensitivity to potassium, while maintaining the high pH needed to inhibit the corrosion of stored nuclear fuel.

Nano-silicon and sodium mitigate damage by potassium deficiency in chicory.

Chicory is a food with high nutritional. The use of beneficial elements in plants, such as sodium (Na) and silicon (Si), may be important to mitigate nutritional disorders, such as potassium (K) deficiency, but research is lacking on this topic. The objective was to evaluate the effects of sodium and nano-silicon on the nutritional, physiological, growth, and quality parameters of chicory under K deficiency and sufficiency. We used a concentration for sufficient K (3.0 mmol L-1), K-deficiency (1.5 mmol L-1), combined with the lack or presence of Na (2.0 mmol L-1) and Si (2.0 mmol L-1). The experiment was carried out in a greenhouse with six treatments corresponding to K sufficiency, K-sufficiency with Na, K-sufficiency with Si, K deficiency, K-deficiency with Na, and K-deficiency with Si, with six replications. The following growth variables were evaluated: (i) plant height, (ii) stem diameter, (iii) number of leaves, (iv) leaf area, and (v) plant biomass. Potassium and Si contents in the above ground part and K utilization efficiency were assessed, and the accumulation of K, Na, and Si was calculated. The efficiency of the quantum yield of photosystem II (Fv/Fm) and the photosynthetic pigments was determined. Electrolyte leakage index and relative water content, as well as phenolic compounds, ascorbic acid, and leaf firmness index were also determined. We found that supplying nano-Si and Na to a K-deficient nutrient solution increased K accumulation by 60% and 50% and K use efficiency by 79% and 62% compared to plants without supply of those elements. Nano-Si reduced electrolyte leakage, being 41% less than Na in K-deficient chicory. However, when Na was added to a nutrient solution with sufficient potassium, the K use efficiency decreased by 48% compared to sufficient potassium without Na. Under the same condition of sufficient supply of potassium and Na, K accumulation decreased by 20% in chicory compared to sufficient potassium without Na, and the photosynthetic pigments-total chlorophyll and carotenoids-were reduced by 5% and 10%, respectively. Our findings contribute to improve cultivation systems with low supply of K as the supply of Na and nano-Si mitigates the damage caused to the metabolism of chicory under K deficiency.

Activity-dependent extracellular potassium changes in unmyelinated versus myelinated areas in olfactory regions of the isolated female guinea-pig brain.

The potassium released in the extracellular space during neuronal activity is rapidly removed by glia and neurons to maintain tissue homeostasis. Oligodendrocyte-derived myelin axonal coating contributes to potassium buffering and is therefore crucial to control brain excitability. We studied activity-dependent extracellular potassium ([K+]o) changes in the piriform cortex (PC), a region that features highly segregated bundles of myelinated and unmyelinated fibers. Four-aminopyridine (4AP; 50 µM) treatment or patterned high-frequency stimulations (hfST) were utilized to generate [K+]o changes measured with potassium-sensitive electrodes in the myelinated lateral olfactory tract (LOT), in the unmyelinated PC layer I and in the myelinated deep PC layers in the ex vivo isolated guinea-pig brain. Seizure-like events induced by 4AP are initiated by the abrupt [K+]o rise in the layer I formed by unmyelinated fibers (Uva et al., 2017). Larger [K+]o shifts occurred in unmyelinated layers compared to the myelinated LOT. LOT hfST that mimicks pre-seizure discharges also generated higher [K+]o changes in unmyelinated PC layer I than in LOT and deep PC layers. The treatment with the Kir4.1 potassium channel blocker BaCl2 (100 µM) enhanced the [K+]o changes generated by hfST in myelinated structures. Our data show that activity-dependent [K+]o changes are intrinsically different in myelinated vs unmyelinated cortical regions. The larger [K+]o shifts generated in unmyelinated structures may represent a vehicle for seizure generation.

ER-to-lysosome Ca2+ refilling followed by K+ efflux-coupled store-operated Ca2+ entry in inflammasome activation and metabolic inflammation.

We studied lysosomal Ca2+ in inflammasome. Lipopolysaccharide (LPS) + palmitic acid (PA) decreased lysosomal Ca2+ ([Ca2+]Lys) and increased [Ca2+]i through mitochondrial ROS, which was suppressed in Trpm2-KO macrophages. Inflammasome activation and metabolic inflammation in adipose tissue of high-fat diet (HFD)-fed mice were ameliorated by Trpm2 KO. ER→lysosome Ca2+ refilling occurred after lysosomal Ca2+ release whose blockade attenuated LPS + PA-induced inflammasome. Subsequently, store-operated Ca2+entry (SOCE) was activated whose inhibition suppressed inflammasome. SOCE was coupled with K+ efflux whose inhibition reduced ER Ca2+ content ([Ca2+]ER) and impaired [Ca2+]Lys recovery. LPS + PA activated KCa3.1 channel, a Ca2+-activated K+ channel. Inhibitors of KCa3.1 channel or Kcnn4 KO reduced [Ca2+]ER, attenuated increase of [Ca2+]i or inflammasome activation by LPS + PA, and ameliorated HFD-induced inflammasome or metabolic inflammation. Lysosomal Ca2+ release induced delayed JNK and ASC phosphorylation through CAMKII-ASK1. These results suggest a novel role of lysosomal Ca2+ release sustained by ER→lysosome Ca2+ refilling and K+ efflux through KCa3.1 channel in inflammasome activation and metabolic inflammation.

Outward potassium current in neurons of aestivated land snail Achatina fulica.

Aestivation and hibernation represent distinct forms of animal quiescence, characterized by physiological changes, including ion composition. Intracellular ion flows play a pivotal role in eliciting alterations in membrane potential and facilitating cellular communication, while outward K+ currents aid in the restitution and upkeep of the resting membrane potential. This study explores the relationship between inward and outward currents during aestivation in Achatina fulica snails. Specimens were collected near MSUBIT University in Shenzhen and divided into two groups. The first group was kept on a lattice diet, while the second one consisted of aestivating individuals, that were deprived of food and water until a cork-like structure sealed their shells. Recording of current from isolated neurons were conducted using the single-electrode voltage clamp mode with an AxoPatch 200B amplifier. Electrophysiological recordings on pedal ganglia neurons revealed significant differences in the inactivation processes of the Ia and Ikdr components. Alterations in the Ikdr component may inhibit pacemaker activity in pedal ganglion neurons, potentially contributing to locomotion cessation in aestivated animals. The KS current remains unaffected during aestivation. Changes in slow K+ current components could disrupt the resting membrane potential, possibly leading to cell depolarization and influx of Ca2+ and Na+ ions, impacting cell homeostasis. Thus, maintaining the constancy of outward K+ current is essential for cell stability.

Characterization of hyperactive mutations in the renal potassium channel ROMK uncovers unique effects on channel biogenesis and ion conductance.

Hypertension affects one billion people worldwide and is the most common risk factor for cardiovascular disease, yet a comprehensive picture of its underlying genetic factors is incomplete. Amongst regulators of blood pressure is the renal outer medullary potassium (ROMK) channel. While select ROMK mutants are prone to premature degradation and lead to disease, heterozygous carriers of some of these same alleles are protected from hypertension. Therefore, we hypothesized that gain-of-function (GoF) ROMK variants which increase potassium flux may predispose people to hypertension. To begin to test this hypothesis, we employed genetic screens and a candidate-based approach to identify six GoF variants in yeast. Subsequent functional assays in higher cells revealed two variant classes. The first group exhibited greater stability in the endoplasmic reticulum, enhanced channel assembly, and/or increased protein at the cell surface. The second group of variants resided in the PIP2-binding pocket, and computational modeling coupled with patch-clamp studies demonstrated lower free energy for channel opening and slowed current rundown, consistent with an acquired PIP2-activated state. Together, these findings advance our understanding of ROMK structure-function, suggest the existence of hyperactive ROMK alleles in humans, and establish a system to facilitate the development of ROMK-targeted antihypertensives.

Salinity-induced variations in wheat biomass are regulated by the Na+:K+ ratio, root exudates, and keystone species.

Salt stress can limit crop productivity, and there are differences in salt tolerance among plant varieties; however, we lack a comprehensive understanding of how keystone species obtained from different plant varieties under salt stress change plant biomass by driving root exudate secretion and regulating the Na+:K+ ratio. We conducted a pot experiment for three wheat varieties (JiMai32 (JM32), XiaoYan60 (XY60), and ShanRong3 (SR3)) under saline/nonsaline soil conditions. Salt stress tended to significantly reduce wheat biomass, and the biomass reduction rates of the different varieties decreased in the order JM32 < XY60 < SR3. The compositions of the bacterial and fungal communities in the root endosphere, rhizosphere and bulk soil were measured, and salt-induced microbial taxa were isolated to identify keystone species from the co-occurrence networks and to study their effects on physiological responses to salinity in wheat varieties. We observed that root exudates participated in the regulation of the Na+:K+ ratio, thereby affecting wheat biomass, and this process was regulated by keystone species. JM32 was enriched in microorganisms that promote plant growth and resistance to salt stress, such as Burkholderiales, Sordariomycetes, Alteromonadaceae, Acremonium, and Dokdonella, and inhibited microorganisms that are sensitive to the environment (salt, nutrients) and plant pathogens, such as Nocardioidaceae, Nitrospira, Cytophagaceae, Syntrophobacteriaceae, and Striaticonidium. XY60 inhibited microorganisms with biological control and disease inhibition potential, such as Agromyces and Kaistobacter. SR3-enriched pathogens, such as Aurantimonadaceae and Pseudogymnoascus, as well as microorganisms with antagonistic pathogen potential and the ability to treat bacterial infections, such as RB41 and Saccharothrix, were inhibited. Our results confirmed the crucial function of salt-induced keystone species in enhancing plant adaptation to salt stress by driving root exudate secretion and regulating the Na+:K+ ratio, with implications for exploring reasonable measures to improve plant salt tolerance.

Soil nutrients and enzyme activities based on millet continuous cropping obstacles.

In order to evaluate the effects of continuous cropping of millet on soil nutrients and soil enzyme activities, the present study was based on four treatments of 2 years of continuous cropping (T1), 3 years of continuous cropping (T2), 4 years of continuous cropping (T3) and rotational cropping (CK), based on 4 years of no fertilizer positioning experiments, and the soil nutrients, soil enzyme activities and millets yields were determined, respectively. The results showed that with the increase of continuous cropping years, the millet yield decreased and was significantly lower than that of rotating with legume crops, and compared with CK, the yields of T1, T2 and T3 treatments were reduced by 8.92%, 13.73% and 37.60%, respectively; the soil nitrogen and phosphorus contents were reduced, the quick-acting potassium content did not change obviously, and the soil pH was increased; Soil urease, alkaline phosphatase, sucrase and catalase activities generally showed a decreasing trend and the decrease was more significant with the increase in the number of years of continuous cropping. Therefore, in order to maintain the soil fertility and increase the millet yield, it is necessary to practice crop rotation and stubble reversal between millets and leguminous crops such as kidney beans, and to apply certain fertilizers.

Effects of extra potassium supply and rootstocks indicate links between water, solutes and energy in Shiraz grapevines (Vitis vinifera) pericarps.

Potassium (K) is essential for the development of grapevines (Vitis vinifera ), accumulating into berries during maturation. Elevated K has been associated with high sugar and low acidity in juice. Characterising the accumulation patterns of K and other components in pericarps treated with various experimental factors may indicate potential regulators of berry K levels. A soil fertiliser trial using nutrient solutions with two K supply rates was conducted on potted Shiraz vines during berry ripening. Doubled-K supply increased L-malic acid content in the early-ripening phase, and increased K and magnesium concentrations in the late-ripening phase. Doubled-K supply reduced the ratio of K to sodium in later ripening phases, suggesting that the accumulation of K relative to sodium was limited in more mature berries supplied with extra K. Pericarp water percentage, sugar, K and ATP were correlated in both treatments, indicating links between hydration, solute transport and energy in maturing berries. In a separate rootstock trial over the two growing seasons, Shiraz scions grafted onto 420-A rootstock produced berries with lower K concentration and content than those grafted onto Ramsey or Ruggeri-140 rootstocks and own-rooted vines. This study demonstrated that the K supply and berry ripening phase impacted the berry K level.

Mitigating NaCl stress in Vigna radiata L. cultivars using Bacillus pseudomycoides.

Salt stress is one of the significant abiotic stress factors that exert harmful effects on plant growth and yield. In this study, five cultivars of mung bean (Vigna radiata L.) were treated with different concentrations of NaCl and also inoculated with a salt-tolerant bacterial strain to assess their growth and yield. The bacterial strain was isolated from the saline soil of Sahiwal District, Punjab, Pakistan and identified as Bacillus pseudomycoides. Plant growth was monitored at 15-days interval and finally harvested after 120 days at seed set. Both sodium and potassium uptake in above and below-ground parts were assessed using a flame photometer. Fresh and dry mass, number of pods, seeds per plant, weight of seeds per plant and weight of 100 seeds reduced significantly as the concentration of NaCl increased from 3 to 15 dSm-1. There was a significant reduction in the growth and yield of plants exposed to NaCl stress without bacterial inoculum compared to the plants with bacterial inoculum. The latter plants showed a significant increase in the studied parameters. It was found that the cultivar Inqelab mung showed the least reduction in growth and yield traits among the studied cultivars, while Ramzan mung showed the maximum reduction. Among all the cultivars, maximum Na+ uptake occurred in roots, while the least uptake was observed in seeds. The study concludes that NaCl stress significantly reduces the growth and yield of mung bean cultivars, but Bacillus pseudomycoides inoculum alleviates salt stress. These findings will be helpful to cultivate the selected cultivars in soils with varying concentrations of NaCl.

Combined activation of artificial and natural ion channels for disrupting mitochondrial ion homeostasis towards effective postoperative tumor recurrence and metastasis suppression.

Rationale: Pharmacological targeting of mitochondrial ion channels is developing as a new direction in cancer therapy. The opening or closing of these channels can impact mitochondrial function and structure by interfering with intracellular ion homeostasis, thereby regulating cell fate. Nevertheless, their abnormal expression or regulation poses challenges in eliminating cancer cells, and further contributes to metastasis, recurrence, and drug resistance. Methods: We developed an engineered mitochondrial targeted delivery system with self-reinforcing potassium ion (K+) influx via amphiphilic mitochondrial targeting polymer (TMP) as carriers to co-deliver natural K+ channel agonists (Dinitrogen oxide, DZX) and artificial K+ channel molecules (5F8). Results: Using this method, DZX specifically activated natural K+ channels, whereas 5F8 assembled artificial K+ channels on the mitochondrial membrane, leading to mitochondrial K+ influx, as well as oxidative stress and activation of the mitochondrial apoptotic pathway. Conclusion: The synergistic effect of 5F8 and DZX presents greater effectiveness in killing cancer cells than DZX alone, and effectively inhibited tumor recurrence and lung metastasis following surgical resection of breast cancer tumors in animal models. This strategy innovatively integrates antihypertensive drugs with artificial ion channel molecules for the first time to effectively inhibit tumor recurrence and metastasis by disrupting intracellular ion homeostasis, which will provide a novel perspective for postoperative tumor therapy.

The Dynamic Clamp Technique: A Robust Toolkit for Investigating Potassium Channel Function.

The dynamic clamp technique has emerged as a powerful tool in the field of cardiac electrophysiology, enabling researchers to investigate the intricate dynamics of ion currents in cardiac cells. Potassium channels play a critical role in the functioning of cardiac cells and the overall electrical stability of the heart. This chapter provides a comprehensive overview of the methods and applications of dynamic clamp in the study of key potassium currents in cardiac cells. A step-by-step guide is presented, detailing the experimental setup and protocols required for implementing the dynamic clamp technique in cardiac cell studies. Special attention is given to the design and construction of a dynamic clamp setup with Real Time eXperimental Interface, configurations, and the incorporation of mathematical models to mimic ion channel behavior. The chapter's core focuses on applying dynamic clamp to elucidate the properties of various potassium channels in cardiac cells. It discusses how dynamic clamp can be used to investigate channel kinetics, voltage-dependent properties, and the impact of different potassium channel subtypes on cardiac electrophysiology. The chapter will also include examples of specific dynamic clamp experiments that studied potassium currents or their applications in cardiac cells.

Effects of biochar types on seed germination, growth, chlorophyll contents, grain yield, sodium, and potassium uptake by wheat (Triticum aestivum L.) under salt stress.

Soil salinity is a significant challenge in agriculture, particularly in arid and semi-arid regions such as Pakistan, leading to soil degradation and reduced crop yields. The present study assessed the impact of different salinity levels (0, 25, and 50 mmol NaCl) and biochar treatments (control, wheat-straw biochar, rice-husk biochar, and sawdust biochar applied @ 1% w/w) on the germination and growth performance of wheat. Two experiments: a germination study and a pot experiment (grown up to maturity), were performed. The results showed that NaCl-stress negatively impacted the germination parameters, grain, and straw yield, and agronomic and soil parameters. Biochar treatments restored these parameters compared to control (no biochar), but the effects were inconsistent across NaCl levels. Among the different biochars, wheat-straw biochar performed better than rice-husk and sawdust-derived biochar regarding germination and agronomic parameters. Biochar application notably increased soil pHs and electrical conductivity (ECe). Imposing NaCl stress reduced K concentrations in the wheat shoot and grains with concomitant higher Na concentrations in both parts. Parameters like foliar chlorophyll content (a, b, and total), stomatal and sub-stomatal conductance, and transpiration rate were also positively influenced by biochar addition. The study confirmed that biochar, particularly wheat-straw biochar, effectively mitigated the adverse effects of soil salinity, enhancing both soil quality and wheat growth. The study highlighted that biochar application can minimize the negative effects of salinity stress on wheat. Specifically, the types and dosages of biochar have to be optimized for different salinity levels under field conditions.