Search Results (142)

Fresh fruit are highly perishable commodities, facing significant postharvest losses primarily due to physiological deterioration and microbial spoilage. Conventional preservation methods often face limitations regarding safety, residue, and environmental impact. Because of its rapid decomposition and low-residue-impact characteristics, ozone has proven superior as an efficient and eco-friendly solution for preserving fruit quality after harvest. The maturation and aging processes of kiwifruit are closely linked to the involvement of reactive oxygen species (ROS) metabolism. This study aimed to investigate the effects of intermittent ozone treatment (21.4 mg/m³, applied for 0, 1, 3, or 5 h weekly) on ROS metabolism, the antioxidant defense system, and storage quality of kiwifruit during cold storage (0.0 ± 0.5 °C). The results showed ozone treatment slowed the decline in titratable acid (TA) content and fruit firmness, inhibited increases in total soluble solids (TSSs) and weight loss, and maintained the storage quality. Additionally, ozone treatment enhanced the activities of antioxidant-related enzymes. This includes superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX). Furthermore, it delayed the reduction in ascorbate (ASA), glutathione (GSH), total phenolic compounds, and flavonoid content, while also preventing the accumulation of ROS and the rise in malondialdehyde (MDA) levels. In summary, the results indicate that ozone treatment enhances the antioxidant capacity of kiwifruit by increasing the structural integrity of cell membranes, preserving the structural integrity of cell membranes, and effectively maintaining the storage quality of the fruit. Full article

Banana fruits are harvested and then undergo rapid ripening and senescence, sharply limiting their shelf-life and marketability. Myo-inositol (MI) is an important regulator in ethylene production and reactive oxygen species (ROS) accumulation; however, its involvement in the postharvest ripening process of banana remains to be determined. This study found that postharvest application of MI could efficiently delay the fruit ripening and extend the time in which the luster, color, and hardness were maintained in two cultivars with contrasting storage characteristics, storable ‘Brazil’ and unstorable ‘Fenza No. 1’, when stored at room temperature (23 °C ± 2 °C). Moreover, physiological, metabolic, and gene expression analyses indicated that MI application improved MI metabolism and postponed ethylene biosynthesis and cell wall loosening. The decrease in ethylene production was associated with a reduction in the expression of ACS1 and ACO1 genes. MI treatment decreased the expressions of PL1/2, PG, and EXP1/7/8, which may account for the delay in softening. In addition, the application of MI could alleviate ROS-mediated senescence and cell membrane damage by promoting the activities of SOD, POD, and anti-O₂⁻ and decreasing PPO activity. This study shed light on the function of MI in regulating the postharvest ripening and senescence of bananas and provided an efficient strategy for extending shelf-life and reduce losses. Full article

The fungal kingdom, with an estimated five million species, has undergone extensive diversification over the past billion years and now occupies a wide array of ecological niches from terrestrial to aquatic ecosystems. To thrive in such diverse environments, fungi must exhibit finely tuned physiological and morphological responses orchestrated by conserved molecular pathways. Increasing evidence suggests that aquaporins (AQPs) play a key role in mediating these adaptive responses, particularly under varying abiotic and biotic stress conditions. However, despite notable advances in recent decades, the precise functional roles of AQPs within the fungal kingdom remains largely unresolved in the field of cell biology. AQPs are transmembrane proteins belonging to the major intrinsic proteins (MIPs) superfamily, which is characterized by remarkable sequence and structural diversity. Beyond their established function in facilitating water transport, MIPs mediated the bidirectional diffusion of a range of small inorganic and organic solutes, ions, and gases across cellular membranes. In fungi, MIPs are classified into three main subfamilies: orthodox (i.e., classical) AQPs, aquaglyceroporins (AQGP), and X-intrinsic proteins (XIPs). This review provides a concise summary of the fundamental structural and functional characteristics of fungal aquaporins, including their structure, classification, and known physiological roles. While the majority of the current literature has focused on the aquaporin and aquaglyceroporin subfamilies, this review also aims to offer a comprehensive and original overview of the relatively understudied X-intrinsic protein subfamily, highlighting its potential implication in fungal biology. Full article

Cardiomyocytes, similarly to cells in various tissues, are responsive to mechanical stress of all types, which is reflected in the significant alterations to their electrophysiological characteristics. This phenomenon, known as mechanoelectric feedback, is based on the work of mechanically gated channels (MGCs) and mechano-sensitive channels (MSCs). Since microgravity (MG) in space, as well as simulated microgravity (SMG), changes the morphological and physiological properties of the heart, it was assumed that this result would be associated with a change in the expression of genes encoding MGCs and MSCs, leading to a change in the synthesis of channel proteins and, ultimately, a change in channel currents during cell stretching. In isolated ventricular cardiomyocytes of rats exposed to SMG for 14 days, the amount of MGCs and MSCs gene transcripts was studied using the RNA sequencing method by normalizing the amount of “raw” reads using the Transcripts Per Kilobase Million (TPM) method. Changes in the level of channel protein, using the example of the MGCs TRPM7, were assessed by the Western blot method, and changes in membrane ion currents in the control and during cardiomyocyte stretching were assessed by the patch-clamp method in the whole-cell configuration. The data obtained demonstrate that SMG results in a multidirectional change in the expression of genes encoding various MGCs and MSCs. At the same time, a decrease in the TPM of the MGCs TRPM7 gene leads to a decrease in the amount of TRPM7 protein. The resulting redistribution in the synthesis of most channel proteins leads to a marked decrease in the sensitivity of the current through MGCs to cell stretching and, ultimately, to a change in the functioning of the heart. Full article

Particulate matter affects both the light environment and air quality in greenhouses, obstructing normal gas exchange and hindering efficient physiological activities such as photosynthesis. This study focused on young Chinese cabbage (Brassica rapa L. Chinensis Group) in a greenhouse at harvest time, monitoring and comparing hyperspectral information, net photosynthetic rate, and microscopic leaf structure under two conditions: a quantitative artificial particulate matter environment and a healthy environment. Based on microscopic results combined with spectral responses and changes in photosynthetic physiological information, it is believed that particulate matter enters plant cells through stomata. Through retention and transport pathways, it disrupts the membrane structure, organelles, and other components of plant cells, resulting in adverse effects on the plant’s physiological functions. The study analyzed the mechanisms by which particulate matter influences the photosynthesis, spectral characteristics, and physiological responses of young Chinese cabbage. Physiological Reflectance Index (PRI), Modified Chlorophyll Absorption Ratio Index (MCARI), spectral red-edge position (λr), and spectral sensitive bands were used as spectral feature variables. Through cubic polynomial and 24 combinations of spectral preprocessing and modeling methods, an inversion model of spectral features and net photosynthetic rate was established. The optimal combination of spectral preprocessing and modeling methods was finally selected as SG + SD + PLS + MSC, which consists of Savitzky-Golay smooth (SG), second derivative (SD), partial least squares (PLS), and multiplicative scatter correction (MSC). The coefficient of determination (R²) of the model is 0.9513. The results indicate that particulate matter affects plant photosynthesis. The SG + SD + PLS + MSC combination method is relatively advantageous for processing the photosynthetic spectral physiological information of plants under the influence of particulate matter. The results of this study will deepen the understanding of the mechanisms by which particulate matter affects plants and provide a reference for the physiological information inversion of greenhouse vegetables under particulate matter pollution. Full article

This study aims to evaluate the tolerance of an endophytic fungus isolated from the fibrous roots of Gentiana yunnanensis Franch. to arsenic (As) and elucidate the underlying physiological and molecular mechanisms. The filamentous fungus is identified as Cladosporium cladosporioides based on morphological characteristics and phylogenetic tree analysis, belonging to the family Moniliaceae and Phyla Hyphomycetes. The tolerance of C. cladosporioides to As(V) was assessed by measuring its biomass under varying concentrations of As(V). The fungus exhibited remarkable As(V) tolerance, with an EC₅₀ value of 2051.94 mg/L, and accumulated high concentrations of As in its mycelium. Subcellular distribution analysis revealed that As was predominantly localized in the cell wall fraction, with levels 4.06 times higher than those in the non-cell wall fraction. Notably, the concentrations of total organic As and As(III) in the mycelium were 852.75 μg/g and 24.94 μg/g, respectively, with conversion ratios of 76.64% and 2.24%. The organic As levels significantly surpassed both As(V) and As(III) concentrations in all cellular fractions (cell wall and non-cell wall components), demonstrating particularly efficient As transformation in C. cladosporioides. Under As(V) stress, the membrane antioxidant system, including superoxide dismutase (SOD), metallothionein (MT), glutathione (GSH), and melanin, was activated and significantly enhanced to mitigate oxidative damage. Transcriptomic analysis identified 4771 differentially expressed genes (DEGs; 2527 upregulated), including highly expressed As-responsive genes (CcArsH_1, CcARR_1, CcARR_3, CcGST_1, and CcGST_3). Strong correlations emerged between As speciation (total/organic/As(V)/As(III)), antioxidant levels, and DEG expression patterns. Taken together, these findings demonstrate that C. cladosporioides employs a multi-faceted As detoxification strategy involving subcellular distribution and reductive transformation (As(V) to As(III)/organic As), antioxidant system enhancement, transcriptomic adaptations, and integrated defense strategy. This work highlights C. cladosporioides potential for As bioremediation and elucidates As accumulation mechanisms in G. yunnanensis. Full article

Although lactic acid bacteria (LABs) possess unique metabolic and physiological characteristics that have crucial effects on the transport of substances both into and out of the cell, there is still a lack of systematic research on membrane transporters in LABs and their roles in material transport. In this study, genomic data for the species Lactobacillus delbrueckii, Streptococcus thermophilus, Leuconostoc lactis, Pediococcus lactis, Lactococcus garvieae, and Bifidobacterium lactis were analyzed to identify the associated transport systems, including what kind of substances are transported. As part of a comparative genomics approach, we used the G-BLAST and AveHAS programs in the TCDB database to screen for transport proteins and clarify the distribution of these proteins in different Lactobacillus strains, allowing for further prediction of their transport substrates. Studies have shown that the distributions of these transporters differ among the selected LAB strains. Through screening and tabulation, we found that the content of transporters in the six LAB proteomes was greater than 20%, with the dominance of the large transporter group indicating complex metabolic and probiotic effects. Furthermore, it was found that the LAB strains contain a variety of homologs of drug-efflux proteins, which may make them resistant to antibiotics, as well as a large number of toxin-related transporters. This study allowed for reasonable predictions of the roles of toxin-related proteins in LABs, and further research on these proteins may be valuable for understanding the probiotic effects of LABs that arise through competition. The study of LAB transporters and the prediction of their functions might support a better understanding of the metabolic and physiological activities of these bacteria. In the future, we aim to extract DNA from laboratory strains and perform PCR amplification using suitable primers designed by us. Through comparison of the obtained gene sequences with those reported in this study, we can explore the differences among them. Full article

Calcium movement and concentration in the cell plays significant roles in normal physiology and in diseases such as cancer. The significance of this ion in oncogenesis suggests that membrane-relevant proteins are involved in its regulation and are deregulated in various cancers. These channels and transporters could be targets for therapeutic interventions. An evaluation of the expression of transient receptor potential (TRP) channels in prostate cancer was performed using publicly available genomic and proteome data. Two TRP family members with high expression in prostate cancers, TRPML2 and TRPM4, were chosen for further analysis the uncover the associations of their level of expression with clinical and pathologic prostate cancer characteristics. Several TRP channels were expressed in prostate cancers at the protein level including TRPM4, TRPML1, TRPML2, TRPC1 and TRPP3. At the mRNA level, MCOLN2 and TRPM4 were strongly expressed in a sub-set of prostate cancers. Cases with high MCOLN2 mRNA expression were associated with frequent ERG fusions and a trend for better survival outcomes. In contrast, prostate cancer cases with high TRPM4 mRNA expression were associated with lower ERG fusion frequency than cases with low TRPM4 mRNA expression. The prognosis of prostate cancers with high TRPM4 expression was not different from the prognosis with counterparts having low TRPM4 mRNA expression. TRP channels were expressed in sub-sets of prostate cancers. The two well-expressed channels of the super family, TRPML2 and TRPM4, have divergent associations with the most prevalent prostate cancer molecular aberrations, ERG fusions. These results imply diverse regulations of the TRP channels that would have to be taken into consideration when devising therapeutic interventions targeting individual channels. Full article

Guizhou Province is one of the regions in China where macadamia is cultivated. The area is characterized by prominent karst landforms, with uneven distribution of precipitation and utilizable water resources, which poses significant challenges to macadamia production. To explore the effects of different drought levels on the anatomical structure and physiological characteristics of macadamia seedlings, and to reveal their adaptation mechanisms and regulatory responses to drought stress, this study established a drought stress experiment on O.C (Own Choice) macadamia seedlings. The seedlings were subjected to stress in a 25% PEG-6000 solution for 0 h (CK), 24 h, 36 h, 48 h, and 72 h, and cellular structural features of stems and leaves were measured, as well as physiological and biochemical indices. The results indicated that macadamia seedlings gradually exhibited dehydration and chlorosis with prolonged drought stress. At 72 h of drought stress, root water potential, leaf water potential, chlorophyll content, relative water content, and root activity decreased by 353%, 98%, 44%, 72%, and 79%, respectively. Leaf thickness, palisade tissue thickness, and spongy tissue thickness were reduced by 19%, 33%, and 29%, respectively. Stomatal density increased by 50%, while stomatal aperture, vessel diameter, and cell wall thickness significantly decreased. Photosynthesis was markedly impaired: Pn, Tr, Gs, WUE, Fv/Fm, qP, and ΦPSII declined by 73%, 25%, 67%, 64%, 0.23, 60%, and 84%, respectively, whereas Ci and qN increased by 107% and 11%, respectively. Cell membranes began to sustain damage after 24 h of drought stress, with electrolyte leakage and MDA content rising by 266% and 672%, respectively, at 72 h. Prolonged drought stress reduced IAA, CTK, and GA levels by 37%, 33%, and 16%, respectively, while ABA content increased by 48%. To counteract drought stress, seedlings activated osmotic adjustment and reactive oxygen species (ROS) scavenging mechanisms. Osmolyte content significantly increased with stress duration, reaching 61%, 73%, 697%, and 107% increments in SS, SP, Pro, and betaine at 72 h. Antioxidant enzyme activities initially rose, peaking at 24 h (SOD, POD, CAT, and APX increased by 132%, 288%, 110%, and 46%, respectively), then gradually declined. By 72 h, SOD and APX activities fell below control levels, while POD and CAT remained elevated. These findings demonstrate that under PEG-6000-simulated drought stress, macadamia seedlings alleviate damage by modifying leaf and stem cellular structures and activating antioxidant and osmotic adjustment mechanisms. This study provides a theoretical basis for understanding the physiological mechanisms of macadamia drought stress response. Full article

The regulation of intracellular NADPH levels is currently a hotspot for research into bacterial modification and fermentation process optimization, and Corynebacterium glutamicum, an important industrial microorganism, achieves enhanced L-lysine production by regulating intracellular NADPH levels. In previous studies, transcriptome analysis was performed on C. glutamicum with different intracellular NADPH levels. The results showed that the expression level of transcription factor AtrN changed significantly. Moreover, experiments showed that transcription factor AtrN can sense high intracellular levels of NADPH and negatively regulate its synthesis. In this study, we integrated the pntAB gene of Escherichia coli into the genome of C. glutamicum XQ-5, successfully constructing a chassis cell with a high intracellular NADPH level. It was named TQ-1. On this basis, we knocked out and complemented the AtrN in strain TQ-1, resulting in strains TQ-2 and TQ-3, respectively. Then, the changes in cell growth, intracellular redox substances and cell membrane among these three strains were investigated. We found that the growth of TQ-2 was inhibited in the early growth stage and the cell survival rate was decreased because of the high increase in the intracellular NADPH level. In addition, the deletion of the AtrN gene also led to a decrease in the fluidity and an increase in the permeability of the cell membrane. Compared with TQ-1, TQ-3 showed slow growth only in the late growth stage, and the fluidity of its cell membrane was also enhanced. This indicates that AtrN guides the cells to make some adaptive changes to maintain cell growth when facing excessive intracellular reductive stress. This will facilitate future research on how potential upstream regulatory genes regulate AtrN and how AtrN regulates downstream genes to cope with cellular reductive stress. It also provides theoretical guidance for the specific modification of high-yield lysine-producing strains. Full article

Cadmium is considered a highly toxic metallic element that does not have any beneficial biological functions for humans or plants. It has been reported that the antagonism of selenium to heavy metal stress has been observed in a variety of plants, and appropriate selenium could alleviate heavy-metal-induced oxidative damage and reduce the accumulation of heavy metals in plants. Changes in physiological characteristics, root tip cells, cadmium concentration, and accumulation of rape under cadmium stress were investigated in this study through pot experiment. Results showed that selenium could alleviate the inhibitory effect of cadmium on the growth of rape seedlings. The concentration and accumulation of cadmium were decreased after the selenium application in rape seeds, ranging from 19.93 to 22.97% and 27.96 to 43.88%, respectively, and the decrease in photosynthetic pigment content induced by cadmium was significantly improved. The results of transmission electron microscopy showed that exogenous selenium and cadmium had metal complexation reaction and formed black precipitation, which may be related to the detoxification effect of selenium on cadmium. More critically, with the addition of selenium, the plasma membrane damage and free radical accumulation in root tips induced by cadmium stress were gradually alleviated in the histochemical staining experiment of rape root tips. These results may provide evidence for exploring effective measures to reduce cadmium accumulation in rape under cadmium-contaminated areas. Full article

Optical spectroscopic methods such as Raman spectroscopy offer several advantages for the analysis of water-soluble polymers (WSPs). There is often no need for complex sample preparation, and measurements are usually rapid, mostly non-destructive and no harmful chemicals are required. In this work, we investigated WSPs and their interaction with bacteria using Raman spectroscopic methods. We analyzed four different WSPs, each with three different molar masses, in solid form using Raman microscopy, and in aqueous solutions using another Raman system designed for measurements in cuvettes, to train predictive models for concentration determination. Thus, we were able to show both the high potential of these approaches, especially for fast and easy investigations both qualitatively and quantitatively, as well as their limitations. Furthermore, we chose one of the molar masses of each tested polymer to carry out extensive Raman spectroscopic investigations with Escherichia coli and Enterococcus faecium, and revealed that bacterial cells exposed to polymers exhibited distinguishable spectral characteristics compared to those not in contact with polymers. Using Raman microscopy combined with partial least squares discriminant analysis (PLS-DA), we effectively distinguished between these groups. Further chemometric analysis indicated potential polymer-induced modifications to the bacterial cell membranes. While this differentiation may partly reflect polymer interactions at the membrane level, it could also correspond to shifts in bacterial growth phases. Together, these findings suggest a complex interplay between polymer exposure and bacterial physiological states. Full article

Understanding the genetic, physiological, and nutritional characteristics of native chickens in South Africa has been significantly hindered by studies over the last ten years. These chickens hold significant economic, social, and cultural importance for South African communities, particularly those marginalized. Despite their reputation for lower egg productivity, they are highly valued for their flavorful meat by consumers. Many local chicken ecotypes and breeds remain undocumented and in danger of going extinct, even though some have been classified. To tackle this issue, the Food and Agriculture Organization has launched an indigenous poultry conservation program. One crucial method employed is assisted reproductive biotechnologies such as cryopreservation, which serves as an ex situ conservation strategy for preserving the germplasm of endangered animals. In avian species, cryopreservation is particularly beneficial for the long-term storage of sperm cells, although it necessitates the use of cryoprotectants to shield sperm cells from cold shock during freezing. However, the use of cryoprotectants can lead to thermal shocks that may damage the sperm cell plasma membrane, potentially reducing viability and fertility. Furthermore, the membranes of avian sperm cells are highly polyunsaturated fatty acids, which can undergo lipid peroxidation (LPO) when reactive oxygen species (ROS) are present. This review focuses on current knowledge and the latest effective strategies for utilizing cryopreservation to conserve semen from indigenous poultry breeds. Full article

Transfusion guidelines worldwide include recommendations regarding the storage length, irradiation, or even donor cytomegalovirus serostatus of red blood cell (RBC) units for anemic neonates. Nevertheless, it is totally overlooked that RBCs of these patients fundamentally differ from those of older children and adults. These differences vary from size, shape, hemoglobin composition, and oxygen transport to membrane characteristics, cellular metabolism, and lifespan. Due to these profound dissimilarities, repeated transfusions of adult RBCs in neonates deeply modify the physiology of circulating RBC populations. Unsurprisingly, the number of RBC transfusions in preterm neonates, particularly if born before 28 weeks of gestation, predicts morbidity and mortality. This review provides a comprehensive description of the biological properties of fetal, cord blood, and neonatal RBCs, including the implications that neonatal RBCs, and their replacement by adult RBCs, may have for perinatal disease pathophysiology. Full article

Ion channels are integral membrane proteins embedded in biological membranes, and they comprise specific proteins that control the flow of ion transporters in and out of cells, playing crucial roles in the biological functions of different cells. They maintain the homeostasis of water and ion metabolism by facilitating ion transport and participate in the physiological processes of neurons and glial cells by regulating signaling pathways. Neurodegenerative diseases are a group of disorders characterized by the progressive loss of neurons in the central nervous system (CNS) or peripheral nervous system (PNS). Despite significant progress in understanding the pathophysiological processes of various neurological diseases in recent years, effective treatments for mitigating the damage caused by these diseases remain inadequate. Increasing evidence suggests that ion channels are closely associated with neuroinflammation; oxidative stress; and the characteristic proteins in neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS). Therefore, studying the pathogenic mechanisms closely related to ion channels in neurodegenerative diseases can help identify more effective therapeutic targets for treating neurodegenerative diseases. Here, we discuss the progress of research on ion channels in different neurodegenerative diseases and emphasize the feasibility and potential of treating such diseases from the perspective of ion channels. Full article