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Scientific Reports Jun 2024Salinity has become a major environmental concern for agricultural lands, leading to decreased crop yields. Hence, plant biology experts aim to genetically improve...
Salinity has become a major environmental concern for agricultural lands, leading to decreased crop yields. Hence, plant biology experts aim to genetically improve barley's adaptation to salinity stress by deeply studying the effects of salt stress and the responses of barley to this stress. In this context, our study aims to explore the variation in physiological and biochemical responses of five Tunisian spring barley genotypes to salt stress during the heading phase. Two salinity treatments were induced by using 100 mM NaCl (T1) and 250 mM NaCl (T2) in the irrigation water. Significant phenotypic variations were detected among the genotypes in response to salt stress. Plants exposed to 250 mM of NaCl showed an important decline in all studied physiological parameters namely, gas exchange, ions concentration and relative water content RWC. The observed decreases in concentrations ranged from, approximately, 6.64% to 40.76% for K, 5.91% to 43.67% for Na, 14.12% to 52.38% for Ca, and 15.22% to 38.48% for Mg across the different genotypes and salt stress levels. However, under salinity conditions, proline and soluble sugars increased for all genotypes with an average increase of 1.6 times in proline concentrations and 1.4 times in soluble sugars concentration. Furthermore, MDA levels rose also for all genotypes, with the biggest rise in Lemsi genotype (114.27% of increase compared to control). Ardhaoui and Rihane showed higher photosynthetic activity compared to the other genotypes across all treatments. The stepwise regression approach identified potassium content, K/Na ratio, relative water content, stomatal conductance and SPAD measurement as predominant traits for thousand kernel weight (R2 = 84.06), suggesting their significant role in alleviating salt stress in barley. Overall, at heading stage, salt accumulation in irrigated soils with saline water significantly influences the growth of barley by influencing gas exchange parameters, mineral composition and water content, in a genotype-dependent manner. These results will serve on elucidating the genetic mechanisms underlying these variations to facilitate targeted improvements in barley's tolerance to salt stress.
Topics: Hordeum; Salt Stress; Water; Minerals; Genotype; Salinity; Sodium Chloride
PubMed: 38942909
DOI: 10.1038/s41598-024-65967-5 -
Journal of Insect Physiology Jun 2024Water regulation is an important physiological challenge for insects due to their small body sizes and large surface area to volume ratios. Adaptations for decreasing...
Water regulation is an important physiological challenge for insects due to their small body sizes and large surface area to volume ratios. Adaptations for decreasing cuticular water loss, the largest avenue of loss, are especially important. The melanin desiccation hypothesis states that melanin molecules in the cuticle may help prevent water loss, thus offering protection from desiccation. This hypothesis has much empirical support in Drosophila species, but remains mostly untested in other taxa, including Lepidoptera. Because melanin has many other important functions in insects, its potential role in desiccation prevention is not always clear. In this study we investigated the role of melanin in desiccation prevention in the white-lined Sphinx moth, Hyles lineata (Lepidoptera, Sphingidae), which shows high plasticity in the degree of melanin pigmentation during the late larval instars. We took advantage of this plasticity and used density treatments to induce a wide range of cuticular melanization; solitary conditions induced low melanin pigmentation while crowded conditions induced high melanin pigmentation. We tested whether more melanic larvae from the crowded treatment were better protected from desiccation in three relevant responses: i) total water loss over a desiccation period, ii) change in hemolymph osmolality over a desiccation period, and iii) evaporation rate of water through the cuticle. We did not find support for the melanin desiccation hypothesis in this species. Although treatment influenced total water loss, this effect did not occur via degree of melanization. Interestingly, this implies that crowding, which was used to induce high melanin phenotypes, may have other physiological effects that influence water regulation. There were no differences between treatments in cuticular evaporative water loss or change in hemolymph osmolality. However, we conclude that osmolality may not sufficiently reflect water loss in this case. This study emphasizes the context dependency of melanin's role in desiccation prevention and the importance of considering how it may vary across taxa. In lepidopteran larvae that are constantly feeding phytophagous insects with soft cuticles, melanin may not be necessary for preventing cuticular water loss.
PubMed: 38936542
DOI: 10.1016/j.jinsphys.2024.104669 -
Journal of Experimental Zoology. Part... Jun 2024Since 2000, a well-established population of the invasive oriental shrimp Palaemon macrodactylus has been present in fully marine conditions in the southwestern Atlantic...
Since 2000, a well-established population of the invasive oriental shrimp Palaemon macrodactylus has been present in fully marine conditions in the southwestern Atlantic Ocean (~38° S). To assess the physiological performance of this atypical population restricted to fully marine conditions, we conducted a laboratory experiment in which individuals were transferred from 35 ‰S (local seawater) to 2 ‰S; 5 ‰S; 10 ‰S; 20 ‰S; 50 ‰S and 60‰ for short (6 h), medium (48 h), and long (>504 h) acclimation periods. We measured the time course response of relevant parameters in the shrimp's hemolymph; activity of Na, K-ATPase (NKA), and V-H-ATPase (VHA); and muscle water content. Shrimp showed great osmoregulatory plasticity, being able to survive for long periods between 5 ‰S and 50 ‰S, whereas no individual survived after transfer to either 2 ‰S or 60 ‰S. Shrimp hyper-regulated hemolymph osmolality at 5 ‰S and 10 ‰S, hypo-regulated at 35 ‰S and 50 ‰S, and isosmoticity was close to 20 ‰S. Compared to 35 ‰S, prolonged acclimation to 5 ‰S caused a decrease in hemolymph osmolality (~34%) along with sodium and chloride concentrations (~24%); the NKA and VHA activities decreased by ~52% and ~88%, respectively, while muscle water content was tightly regulated. Our results showed that the atypical population of P. macrodactylus studied here lives in a chronic hypo-osmo-ion regulatory state and suggest that fully marine conditions contribute to its poor performance at the lower limit of salinity tolerance (<5 ‰S).
PubMed: 38934391
DOI: 10.1002/jez.2843 -
Ecology and Evolution Jun 2024Habitat fragmentation may cut off anadromous salmonids from parts of their potential native habitat and separate previously connected populations. Understanding the...
Habitat fragmentation may cut off anadromous salmonids from parts of their potential native habitat and separate previously connected populations. Understanding the consequences of this is vital for fish management and prioritization of restoration activities. Here, we show that there is a significant difference in the body morphology, physiological stress response, and aspects contributing to aerobic capacity between juvenile anadromous brown trout, , collected at a downstream site and an upstream site, separated by 2 km and several challenging stream sections, in a small unfragmented stream system in western Sweden. Following a standardized stress test, there were significant differences between fish from the upstream and downstream sites (plasma cortisol concentration, plasma osmolality, hematocrit, hemoglobin concentration, and mean corpuscular hemoglobin concentration). Plasma glucose concentration did not significantly differ between fish from the two sites. Fish from the upstream site had larger spleen mass, although there was no evidence of differences in ventricle mass or proportion of compact ventricular myocardium. These physiological differences indicate local variation in stress response and highlight the importance of considering local trait variation in river management. If a section of the river becomes fragmented or degraded, and there are differences in the juveniles in different parts of the river, the consequence for the population might be larger than the proportional loss of habitat.
PubMed: 38932968
DOI: 10.1002/ece3.11526 -
The Journal of the Association of... Jun 2024Acute nondiarrheal illnesses (NDIs) involve overt or subclinical dehydration, requiring rehydration and electrolyte repletion. Dehydration is frequently under-recognized...
Association of Physicians of India Expert Recommendations on Oral Fluid, Electrolytes, and Energy Management during Transition Care and Discharge for Hospitalized Patients with Nondiarrheal Illnesses.
Acute nondiarrheal illnesses (NDIs) involve overt or subclinical dehydration, requiring rehydration and electrolyte repletion. Dehydration is frequently under-recognized and under-managed, both in outpatient departments (OPDs) and inpatient departments (IPDs). Postadmission dehydration is associated with longer hospital stays and higher inhospital mortality rates. Recognizing and understanding dehydration in hospitalized patients is necessary due to the adverse outcomes associated with this condition. In this article, we aimed to develop practical consensus recommendations on the role of oral fluid, electrolyte, and energy (FEE) management in hospitalized patients with FEE deficits in NDI. The modified Delphi consensus methodology was utilized to reach a consensus. A scientific committee comprising eight experts from India formed the panel. Relevant clinical questions within three major domains were formulated for presentation and discussion: (1) burden and factors contributing to dehydration in hospitalized patients; (2) assessment of fluid and electrolyte losses and increased energy requirements in hospitalized patients; and (3) management of FEE deficits in hospitalized patients [at admission, during intravenous (IV) therapy, IV to oral de-escalation, and discharge]. The consensus level was classified into agreement (mean score ≥4), no consensus (mean score <4), and exclusion (mean score <4 after the third round of discussion). The questions that lacked agreement were discussed during the virtual meeting. The experts agreed that the most common factors contributing to dehydration in patients with NDI hospitalized in IPDs include decreased oral fluid intake, increased fluid loss due to the illness, insensible fluid loss, and a lack of awareness among doctors about dehydration, which can result in poor fluid intake. Time constraints, discontinuity of care, lack of awareness of the principles of fluid balance, lack of formal procedures for enforcing hydration schemes, and lack of adequate training are most often barriers to the assessment of hydration status in hospital settings. Experts used hydration biomarkers, such as changes in body weight, serum, or plasma osmolality; fluid intake; and fluid balance charts; along with urine output, frequency, quantity, and color, to determine hydration status in hospital settings. Experts agreed that appropriate FEE supplementation in the form of ready-to-drink (RTD) fluids can restore FEE deficits and shorten the length of hospital stays in hospitalized patients at admission, during de-escalation from IV to oral therapy, and at discharge. RTD electrolyte solutions with known concentrations of electrolytes and energy are good choices to avoid taste fatigue and replenish FEE in hospitalized patients during transition care and at discharge.
Topics: Humans; Fluid Therapy; India; Dehydration; Hospitalization; Patient Discharge; Electrolytes; Consensus; Delphi Technique
PubMed: 38932735
DOI: 10.59556/japi.72.0571 -
The Journal of the Association of... Jun 2024Dehydration is a well-known problem worldwide, and its assessment can be challenging due to confusing physical signs. The most effective way to assess hydration status... (Review)
Review
Dehydration is a well-known problem worldwide, and its assessment can be challenging due to confusing physical signs. The most effective way to assess hydration status is through the costly stable isotope methodology, but this approach has practical limitations. More commonly accepted and utilized indicators of hydration status are hematological and urinary parameters. However, hematological markers require invasive methods, and urinary markers have varying degrees of success in tracking hydration changes. While alterations in body weight can serve as a means of promptly evaluating hydration status, various factors such as food consumption, fluid intake, fecal losses, and urine production can impact these changes. Researchers have turned their attention to saliva as a potential marker and point-of-care (POC) testing to address the limitations of existing biomarkers. Saliva is appealing due to its easy collection process and similarities to extracellular fluid in terms of water and ion concentrations. Recent studies have shown that saliva flow rate, osmolarity/osmolality, and total protein concentration can effectively monitor changes in body mass during acute dehydration. Misdiagnosing dehydration can have severe clinical consequences, leading to morbidity and even mortality. This narrative review focuses on recognizing the significance of hydration assessment, monitoring, and the potential of salivary osmolarity (SOSM) as an assessment tool. Healthcare professionals can improve their practices and interventions to optimize hydration and promote overall wellness using such tools.
Topics: Humans; Saliva; Osmolar Concentration; Dehydration; Biomarkers; Point-of-Care Systems; Organism Hydration Status; Point-of-Care Testing
PubMed: 38932733
DOI: 10.59556/japi.72.0545 -
International Journal of Molecular... Jun 2024is an essential species for freshwater economic aquaculture in China, but in the larval process, their salinity requirement is high, which leads to salinity stress in...
is an essential species for freshwater economic aquaculture in China, but in the larval process, their salinity requirement is high, which leads to salinity stress in the water. In order to elucidate the mechanisms regulating the response of to acute low-salinity exposure, we conducted a comprehensive study of the response of exposed to different salinities' (0‱, 6‱, and 12‱) data for 120 h. The activities of catalase, superoxide dismutase, and glutathione peroxidase were found to be significantly inhibited in the hepatopancreas and muscle following low-salinity exposure, resulting in oxidative damage and immune deficits in . Differential gene enrichment in transcriptomics indicated that low-salinity stress induced metabolic differences and immune and inflammatory dysfunction in . The differential expressions of , , and genes indicated the inhibition of growth, development, and molting ability of . At the proteomic level, low salinity induced metabolic differences and affected biological and cellular regulation, as well as the immune response. Tyramine, trans-1,2-Cyclohexanediol, sorbitol, acetylcholine chloride, and chloroquine were screened by metabolomics as differential metabolic markers. In addition, combined multi-omics analysis revealed that metabolite chloroquine was highly correlated with low-salt stress.
Topics: Animals; Palaemonidae; Larva; Salt Stress; Transcriptome; Proteomics; Salinity; Gene Expression Profiling; Metabolomics; Oxidative Stress; Multiomics
PubMed: 38928514
DOI: 10.3390/ijms25126809 -
Genes Jun 2024We conducted transcriptome sequencing on salt-tolerant mutants X5 and X3, and a control (Ctr) strain of after treatment with artificial seawater at varying salinities...
We conducted transcriptome sequencing on salt-tolerant mutants X5 and X3, and a control (Ctr) strain of after treatment with artificial seawater at varying salinities (30‱, 45‱, and 60‱) for 3 weeks. Differentially expressed genes were identified and a weighted co-expression network analysis was conducted. The blue, red, and tan modules were most closely associated with salinity, while the black, cyan, light cyan, and yellow modules showed a close correlation with strain attributes. KEGG enrichment of genes from the aforementioned modules revealed that the key enrichment pathways for salinity attributes included the proteasome and carbon fixation in photosynthesis, whereas the key pathways for strain attributes consisted of lipid metabolism, oxidative phosphorylation, soluble N-ethylmaleimide-sensitive factor-activating protein receptor (SNARE) interactions in vesicular transport, and porphyrin and chlorophyll metabolism. Gene expression for the proteasome and carbon fixation in photosynthesis was higher in all strains at 60‱. In addition, gene expression in the proteasome pathway was higher in the X5-60 than Ctr-60 and X3-60. Based on the above data and relevant literature, we speculated that mutant X5 likely copes with high salt stress by upregulating genes related to lysosome and carbon fixation in photosynthesis. The proteasome may be reset to adjust the organism's proteome composition to adapt to high-salt environments, while carbon fixation may aid in maintaining material and energy metabolism for normal life activities by enhancing carbon dioxide uptake via photosynthesis. The differences between the X5-30 and Ctr-30 expression of genes involved in the synthesis of secondary metabolites, oxidative phosphorylation, and SNARE interactions in vesicular transport suggested that the X5-30 may differ from Ctr-30 in lipid metabolism, energy metabolism, and vesicular transport. Finally, among the key pathways with good correlation with salinity and strain traits, the key genes with significant correlation with salinity and strain traits were identified by correlation analysis.
Topics: Salt Tolerance; Transcriptome; Gene Regulatory Networks; Salinity; Photosynthesis; Osmotic Pressure; Proteasome Endopeptidase Complex; Gene Expression Profiling; Lipid Metabolism
PubMed: 38927717
DOI: 10.3390/genes15060781 -
BMC Plant Biology Jun 2024Seed heteromorphism is a plant strategy that an individual plant produces two or more distinct types of diaspores, which have diverse morphology, dispersal ability,...
BACKGROUND AND AIMS
Seed heteromorphism is a plant strategy that an individual plant produces two or more distinct types of diaspores, which have diverse morphology, dispersal ability, ecological functions and different effects on plant life history traits. The aim of this study was to test the effects of seasonal soil salinity and burial depth on the dynamics of dormancy/germination and persistence/depletion of buried trimorphic diaspores of a desert annual halophyte Atriplex centralasiatica.
METHODS
We investigated the effects of salinity and seasonal fluctuations of temperature on germination, recovery of germination and mortality of types A, B, C diaspores of A. centralasiatica in the laboratory and buried diaspores in situ at four soil salinities and three depths. Diaspores were collected monthly from the seedbank from December 2016 to November 2018, and the number of viable diaspores remaining (not depleted) and their germinability were determined.
RESULTS
Non-dormant type A diaspores were depleted in the low salinity "window" in the first year. Dormant diaspore types B and C germinated to high percentages at 0.3 and 0.1 mol L soil salinity, respectively. High salinity and shallow burial delayed depletion of diaspore types B and C. High salinity delayed depletion time of the three diaspore types and delayed dormancy release of types B and C diaspores from autumn to spring. Soil salinity modified the response of diaspores in the seedbank by delaying seed dormancy release in autum and winter and by providing a low-salt concentration window for germination of non-dormant diaspores in spring and early summer.
CONCLUSIONS
Buried trimorphic diaspores of annual desert halophyte A. centralasiatica exhibited diverse dormancy/germination behavior in respond to seasonal soil salinity fluctuation. Prolonging persistence of the seedbank and delaying depletion of diaspores under salt stress in situ primarily is due to inhibition of dormancy-break. The differences in dormancy/germination and seed persistence in the soil seedbank may be a bet-hadging strategy adapted to stressful temporal and spatial heterogeneity, and allows A. centralasiatica to persist in the unpredictable cold desert enevironment.
Topics: Germination; Salinity; Salt-Tolerant Plants; China; Soil; Seeds; Atriplex; Seasons; Seed Bank; Plant Dormancy; Temperature
PubMed: 38926703
DOI: 10.1186/s12870-024-05307-x -
Scientific Reports Jun 2024Japanese medaka (Oryzias latipes) has been used as a model organism in different research fields, including reproductive physiology. Sperm motility is the most important...
Japanese medaka (Oryzias latipes) has been used as a model organism in different research fields, including reproductive physiology. Sperm motility is the most important marker for male fertility in fish and, thus, reproduction success. However, because of small volume of ejaculate and short motility duration, it is still challenging to manage the sperm collection and analysis in small model fish. In the present study, we aimed to investigate sperm motility and to optimize sperm collection, short-term sperm storage, and cryopreservation in Japanese medaka (Oryzias latipes). Using two different approaches for sperm collection: testes dissection and abdominal massage, different housing conditions and activating the sperm with different activation solutions, we investigated immediate sperm motility. In the second part of this study, we used different osmolalities of immobilization solution, Hank's Balanced Salt Solution (HBSS) for sperm storage at 0, 2 and 3 h after sperm collection. Finally, the sperm were cryopreserved using methanol as cryoprotectant and HBSS as extender at two different osmolalities, and post-thaw sperm motility was investigated. The highest post-activating sperm motility was achieved in the groups activated by the extender at 300 mOsm/kg. The quality of sperm remained unaffected by co-housing with females or with males only. Furthermore, Hanks' Balanced Salt Solution (HBSS) with an osmolality of 600 mOsm/kg demonstrated its efficacy as a suitable extender for sperm storage, preserving motility and progressivity for 3 h. The highest post-thaw motility was around 35%. There were no significant differences between post-thaw motility in different groups. We also found that post-thaw incubation on ice can maintain the motility of the sperm for up to one hour after thawing.
Topics: Animals; Oryzias; Male; Sperm Motility; Cryopreservation; Spermatozoa; Semen Preservation; Female; Cryoprotective Agents
PubMed: 38926593
DOI: 10.1038/s41598-024-65376-8