-
Frontiers in Plant Science 2024The utilization of plant material for synthesizing nanoparticles effectively triggers physiological and biochemical responses in plants to combat abiotic stresses. Salt...
INTRODUCTION
The utilization of plant material for synthesizing nanoparticles effectively triggers physiological and biochemical responses in plants to combat abiotic stresses. Salt stress, particularly caused by NaCl, significantly affects plant morphology and physiology, leading to reduced crop yields. Understanding the mechanisms of salt tolerance is crucial for maintaining crop productivity.
METHODS
In this study, we examined the effects of 150 μM spinach-assisted gold nanoparticles (S-AuNPs) on various parameters related to seed germination, growth attributes, photosynthetic pigments, stomatal traits, ion concentrations, stress markers, antioxidants, metabolites, and nutritional contents of spinach plants irrigated with 50 mM NaCl.
RESULTS
Results showed that S-AuNPs enhanced chlorophyll levels, leading to improved light absorption, increased photosynthates production, higher sugar content, and stimulated plant growth under NaCl stress. Stomatal traits were improved, and partially closed stomata were reopened with S-AuNPs treatment, possibly due to K/Na modulation, resulting in enhanced relative water content and stomatal conductance. ABA content decreased under S-AuNPs application, possibly due to K ion accumulation. S-AuNPs supplementation increased proline and flavonoid contents while reducing ROS accumulation and lipid peroxidation via activation of both non-enzymatic and enzymatic antioxidants. S-AuNPs also regulated the ionic ratio of K/Na, leading to decreased Na accumulation and increased levels of essential ions in spinach plants under NaCl irrigation.
DISCUSSION
Overall, these findings suggest that S-AuNPs significantly contribute to salt stress endurance in spinach plants by modulating various physiological attributes.
PubMed: 38957605
DOI: 10.3389/fpls.2024.1408642 -
Frontiers in Plant Science 2024The genetic basis of plant response to light and heat stresses had been unveiled, and different molecular mechanisms of leaf cell homeostasis to keep high physiological...
The genetic basis of plant response to light and heat stresses had been unveiled, and different molecular mechanisms of leaf cell homeostasis to keep high physiological performances were recognized in grapevine varieties. However, the ability to develop heat stress tolerance strategies must be further elucidated since the morpho-anatomical and physiological traits involved may vary with genotype × environment combination, stress intensity, and duration. A 3-year experiment was conducted on potted plants of Sardinian red grapevine cultivars Cannonau (syn. Grenache) and Carignano (syn. Carignan), exposed to prolonged heat stress inside a UV-blocking greenhouse, either submitted to low daily UV-B doses of 4.63 kJ m d (+UV) or to 0 kJ m d (-UV), and compared to a control (C) exposed to solar radiation (4.05 kJ m d average UV-B dose). Irrigation was supplied to avoid water stress, and canopy light and thermal microclimate were monitored continuously. Heat stress exceeded one-third of the duration inside the greenhouse and 6% in C. spectroscopy, including leaf reflectance and fluorescence, allowed for characterizing different patterns of leaf traits and metabolites involved in oxidative stress protection. Cannonau showed lower stomatal conductance under C (200 mmol m s) but more than twice the values inside the greenhouse (400 to 900 mmol m s), where water use efficiency was reduced similarly in both varieties. Under severe heat stress and -UV, Cannonau showed a sharper decrease in primary photochemical activity and higher leaf pigment reflectance indexes and leaf mass area. UV-B increased the leaf pigments, especially in Carignano, and different leaf cell regulatory traits to prevent oxidative damage were observed in leaf cross-sections. Heat stress induced chloroplast swelling, plastoglobule diffusion, and the accumulation of secretion deposits in both varieties, aggravated in Cannonau -UV by cell vacuolation, membrane dilation, and diffused leaf blade spot swelling. Conversely, in Carignano UV-B, cell wall barriers and calcium oxalate crystals proliferated in mesophyll cells. These responses suggest an adaptive divergence among cultivars to prolonged heat stress and UV-B light. Further research on grapevine biodiversity, heat, and UV-B light interactions may give new insights on the extent of stress tolerance to improve viticulture adaptive strategies in climate change hotspots.
PubMed: 38957604
DOI: 10.3389/fpls.2024.1399840 -
Frontiers in Plant Science 2024is the queen of the vines, being an ornamental plant with high economic value. Waterlogging stress reduces the ornamental value of the plant and limits its application....
is the queen of the vines, being an ornamental plant with high economic value. Waterlogging stress reduces the ornamental value of the plant and limits its application. Melatonin plays an important role in plant resistance to abiotic stresses. In this study, the physiological responses and gene expression levels of two wild species, namely, and , and two horticultural varieties, namely, 'Sen-No-Kaze' and 'Viva Polonia,' under waterlogging stress were analyzed to determine the effect of melatonin on waterlogging tolerance. The results showed that the waterlogging tolerances of and 'Sen-No-Kaze' were relatively poor, but were significantly improved by concentrations of 100 μmol·L and 50 μmol·L melatonin. and 'Viva Polonia' had relatively strong tolerance to waterlogging, and this was significantly improved by 200 μmol·L melatonin. Under waterlogging stress, the relative conductivity and HO content of increased significantly; the photosynthetic parameters and chlorophyll contents were significantly decreased; photosynthesis was inhibited; the contents of soluble protein and soluble sugars were decreased. Effective improvement of waterlogging tolerance after exogenous melatonin spraying, the relative conductivity was decreased by 4.05%-27.44%; the HO content was decreased by 3.84%-23.28%; the chlorophyll content was increased by 35.59%-103.36%; the photosynthetic efficiency was increased by 25.42%-45.86%; the antioxidant enzyme activities of APX, POD, SOD, and CAT were increased by 28.03%-158.61%; the contents of proline, soluble protein, and soluble sugars were enhanced, and cell homeostasis was improved. Transcription sequencing was performed on wild with differences in waterlogging tolerance, and nine transcription factors were selected that were highly correlated with melatonin and that had the potential to improve waterlogging tolerance, among which , and were significantly positively correlated with the antioxidant enzyme system, and , , and were significantly negatively correlated. Photosynthetic capacity was positively correlated with and while being significantly negatively correlated with , , , and . Melatonin could enhance the flooding tolerance of by improving photosynthetic efficiency and antioxidant enzyme activity. This study provides an important basis and reference for the application of melatonin in waterlogging-resistant breeding of .
PubMed: 38957603
DOI: 10.3389/fpls.2024.1385165 -
Frontiers in Plant Science 2024Water deficit stress triggers various physiological and biochemical changes in plants, substantially affecting both overall plant defense response and thus nutritional...
Water deficit stress triggers various physiological and biochemical changes in plants, substantially affecting both overall plant defense response and thus nutritional quality of tomatoes. The aim of this study was to assess the antioxidant defense response and nutritional quality of different tomato genotypes under water deficit stress. In this study, six tomato genotypes were used and subjected to water deficit stress by withholding water for eight days under glass house conditions. Various physiological parameters from leaves and biochemical parameters from tomato fruits were measured to check the effect of antioxidant defense response and nutritional value. Multi-trait genotype-ideotype distance index (MGIDI) was used for the selection of genotypes with improved defense response and nutritional value under water deficit stress condition. Results indicated that all physiological parameters declined under stress conditions compared to the control. Notably, NBH-362 demonstrated resilience to water deficit stress, improving both defense response and nutritional quality which is evident by an increase in proline (16.91%), reducing sugars (20.15%), total flavonoids (10.43%), superoxide dismutase (24.65%), peroxidase (14.7%), and total antioxidant capacity (29.9%), along with a decrease in total oxidant status (4.38%) under stress condition. Overall, the findings suggest that exposure to water deficit stress has the potential to enhance the nutritional quality of tomatoes. However, the degree of this enhancement is contingent upon the distinct genetic characteristics of various tomato genotypes. Furthermore, the promising genotype (NBH-362) identified in this study holds potential for future utilization in breeding programs.
PubMed: 38957600
DOI: 10.3389/fpls.2024.1403895 -
RSC Advances Jun 2024Hydrogen sulfide (HS) gas plays a significant role in biological regulation. With advancements in technology, HS has been discovered across diverse fields, necessitating...
Hydrogen sulfide (HS) gas plays a significant role in biological regulation. With advancements in technology, HS has been discovered across diverse fields, necessitating a comprehensive understanding of its physiological functions through monitoring changes in HS within complex environments and physiological processes. In this study, we designed a phosphofluorene-based conjugate probe PPF-CDNB with an asymmetric π-conjugated phosphine structure and utilized dinitrophenyl ether as the recognition site for HS. PPF-CDNB exhibited exceptional resistance to interference and demonstrated stability over a broad pH range (3.0-10.0), making it suitable for various environmental conditions. Intracellular experiments revealed that PPF-CDNB effectively monitored both endogenous and exogenous levels of HS.
PubMed: 38957581
DOI: 10.1039/d4ra02979h -
Frontiers in Cellular Neuroscience 2024Microglia are the resident macrophages of the central nervous system (CNS) that control brain development, maintain neural environments, respond to injuries, and... (Review)
Review
Microglia are the resident macrophages of the central nervous system (CNS) that control brain development, maintain neural environments, respond to injuries, and regulate neuroinflammation. Despite their significant impact on various physiological and pathological processes across mammalian biology, there remains a notable gap in our understanding of how microglia perceive and transmit mechanical signals in both normal and diseased states. Recent studies have revealed that microglia possess the ability to detect changes in the mechanical properties of their environment, such as alterations in stiffness or pressure. These changes may occur during development, aging, or in pathological conditions such as trauma or neurodegenerative diseases. This review will discuss microglial Piezo1 mechanosensitive channels as potential therapeutic targets for Alzheimer's disease (AD). The structure, function, and modulation of Piezo1 will be discussed, as well as its role in facilitating microglial clearance of misfolded amyloid-β (Aβ) proteins implicated in the pathology of AD.
PubMed: 38957539
DOI: 10.3389/fncel.2024.1423410 -
Frontiers in Immunology 2024Endocytosis represents a category of regulated active transport mechanisms. These encompass clathrin-dependent and -independent mechanisms, as well as fluid phase... (Review)
Review
Endocytosis represents a category of regulated active transport mechanisms. These encompass clathrin-dependent and -independent mechanisms, as well as fluid phase micropinocytosis and macropinocytosis, each demonstrating varying degrees of specificity and capacity. Collectively, these mechanisms facilitate the internalization of cargo into cellular vesicles. Pregnancy is one such physiological state during which endocytosis may play critical roles. A successful pregnancy necessitates ongoing communication between maternal and fetal cells at the maternal-fetal interface to ensure immunologic tolerance for the semi-allogenic fetus whilst providing adequate protection against infection from pathogens, such as viruses and bacteria. It also requires transport of nutrients across the maternal-fetal interface, but restriction of potentially harmful chemicals and drugs to allow fetal development. In this context, trogocytosis, a specific form of endocytosis, plays a crucial role in immunological tolerance and infection prevention. Endocytosis is also thought to play a significant role in nutrient and toxin handling at the maternal-fetal interface, though its mechanisms remain less understood. A comprehensive understanding of endocytosis and its mechanisms not only enhances our knowledge of maternal-fetal interactions but is also essential for identifying the pathogenesis of pregnancy pathologies and providing new avenues for therapeutic intervention.
Topics: Humans; Pregnancy; Endocytosis; Female; Maternal-Fetal Exchange; Animals; Biological Transport; Nutrients; Immune Tolerance; Placenta
PubMed: 38957469
DOI: 10.3389/fimmu.2024.1415794 -
Frontiers in Chemistry 2024[This corrects the article DOI: 10.3389/fchem.2022.1112362.].
Corrigendum: An in-cluster Sfp-type phosphopantetheinyl transferase instead of the -ACP synthase activates the granaticin biosynthesis under natural physiological conditions.
[This corrects the article DOI: 10.3389/fchem.2022.1112362.].
PubMed: 38957408
DOI: 10.3389/fchem.2024.1443723 -
JBMR Plus Aug 2024Iron is a vital trace element and exerts opposing effects on bone in both iron overload and iron deficiency situations. Remarkably, iron supplementation through... (Review)
Review
Iron is a vital trace element and exerts opposing effects on bone in both iron overload and iron deficiency situations. Remarkably, iron supplementation through intravenous infusion in patients with iron deficiency can also have detrimental effects on bone in special cases. The diverse mechanisms underlying these effects and their manifestations contribute to the complexity of this relationship. Iron overload impacts both bone resorption and formation, accelerating bone resorption while reducing bone formation. These effects primarily result from the direct action of reactive oxygen species (ROS), which influence the proliferation, differentiation, and activity of both osteoclasts and osteoblasts differently. This imbalance favors osteoclasts and inhibits the osteoblasts. Simultaneously, multiple pathways, including bone morphogenic proteins, RANK ligand, and others, contribute to these actions, leading to a reduction in bone mass and an increased susceptibility to fractures. In contrast, iron deficiency induces low bone turnover due to energy and co-factor deficiency, both of which require iron. Anemia increases the risk of fractures in both men and women. This effect occurs at various levels, reducing muscular performance and, on the bone-specific level, decreasing bone mineral density. Crucially, anemia increases the synthesis of the phosphaturic hormone iFGF23, which is subsequently inactivated by cleavage under physiological conditions. Thus, iFGF23 levels and phosphate excretion are not increased. However, in specific cases where anemia has to be managed with intravenous iron treatment, constituents-particularly maltoses-of the iron infusion suppress the cleavage of iFGF23. As a result, patients can experience severe phosphate wasting and, consequently, hypophosphatemic osteomalacia. This condition is often overlooked in clinical practice and is often caused by ferric carboxymaltose. Ending iron infusions or changing the agent, along with phosphate and vitamin D supplementation, can be effective in addressing this issue.
PubMed: 38957399
DOI: 10.1093/jbmrpl/ziae064 -
Frontiers in Neurology 2024Neurogenic hypertension (HTN) is a type of HTN characterized by increased activity of the sympathetic nervous system. Vascular compression is one of the pathogenic...
The effect of microvascular decompression of the CN IX-X root entry/exit zone and the ventrolateral medulla in neurogenic hypertension involving the vertebral/basilar artery.
INTRODUCTION
Neurogenic hypertension (HTN) is a type of HTN characterized by increased activity of the sympathetic nervous system. Vascular compression is one of the pathogenic mechanisms of neurogenic HTN. Despite Jannetta's solid anatomical and physiological arguments in favor of neurogenic HTN in the 1970's, the treatment for essential HTN by microvascular decompression (MVD) still lacks established selection criteria. Therefore, the subjects selected for our center were limited to patients with primary trigeminal neuralgia (TN) and primary hemifacial spasm (HFS) of the vertebral/basilar artery (VA/BA) responsible vessel type coexisting with neurogenic HTN who underwent MVD of the brainstem to further explore possible indications for MVD in the treatment of neurogenic HTN.
METHODS
A retrospective analysis of 63 patients who were diagnosed with neurogenic HTN had symptoms of HFS and TN cranial nerve disease. Patients were treated at our neurosurgery department from January 2018 to January 2023. A preoperative magnetic resonance examination of the patients revealed the presence of abnormally located vascular compression in the rostral ventrolateral medulla (RVLM) and the root entry zone (REZ) of the IX and X cranial nerves (CN IX- X).
RESULTS
There was no significant difference between the two groups in terms of gender, age, course of HFS, course of TN, course of HTN, degree of HTN, or preoperative blood pressure. Based on the postoperative blood pressure levels, nine out of 63 patients were cured (14.28%), eight cases (12.70%) showed a marked effect, 16 cases (25.40%) were effective, and 30 cases were invalid (47.62%). The overall efficacy was 52.38%. However, 39 cases of combined cranial nerve disease were on the left side of the efficacy rate (66.67%) and 24 cases of combined cranial nerve disease were on the right side of the efficacy rate (29.16%).
DISCUSSION
Over the last few decades, many scholars have made pioneering progress in the clinical retrospective study of MVD for neurogenic hypertension, and our study confirms the efficacy of MVD in treating vertebral/basilar artery-type neurogenic hypertension by relieving the vascular pressure of RVLM. In the future, with the development and deepening of pathological mechanisms and clinical observational studies, MVD may become an important treatment for neurogenic hypertension by strictly grasping the surgical indications.
CONCLUSION
MVD is an effective treatment for neurogenic HTN. Indications may include the following: left-sided TN or HFS combined with neurogenic HTN; VA/BA compression in the left RVLM and REZ areas on MRI; and blood pressure in these patients cannot be effectively controlled by drugs.
PubMed: 38957353
DOI: 10.3389/fneur.2024.1376019