Search Results (278)

Macrobrachium nipponense represents a commercial decapod species that predominantly inhabits freshwater ecosystems or environments with low salinity. However, the species exhibits normal survival and reproductive capacity in natural aquatic habitats with salinity levels up to 10 parts per thousand (ppt). The present study aimed to elucidate the molecular mechanisms underlying salinity acclimation in M. nipponense by investigating alterations in oxidative stress, morphological adaptations, and hepatopancreatic gene expression profiles following exposure to a salinity level of 10 ppt. The present study demonstrates that glutathione peroxidase and Na⁺/K⁺-ATPase play critical roles in mitigating oxidative stress induced by elevated salinity in M. nipponense. Furthermore, histological analysis revealed distinct pathological alterations in the hepatopancreas of M. nipponense following 7-day salinity exposure, including basement-membrane disruption, luminal expansion, vacuolization, and a marked reduction in storage cells. Transcriptomic profiling of M. nipponense hepatopancreas suggested coordinated activation of both immune (lysosome and protein processing in endoplasmic reticulum pathways) and energy (pyruvate metabolism, glycolysis/gluconeogenesis, and citrate cycle) metabolic processes during salinity acclimation in M. nipponense. Quantitative real-time PCR validation confirmed the reliability of RNA-seq data. This study provides molecular insights into the salinity adaptation mechanisms in M. nipponense, offering potential applications for improving cultivation practices in brackish water environments. Full article

Global climate change is causing increasing fluctuations in winter temperatures, including episodes of warm conditions above 9 °C. Such events disrupt cold acclimation in plants and can induce deacclimation, reducing frost tolerance and altering, among other things, hormonal regulation. This study investigated hormonal and molecular changes associated with cold acclimation and deacclimation in oilseed rape (Brassica napus L.) cultivars Kuga and Thure. Plants were grown under different conditions: non-acclimated (17 °C for three weeks), cold-acclimated (4 °C for three weeks), and deacclimated (16/9 °C day/night for one week). Detailed hormone analysis included auxins, gibberellins, cytokinins, stress-related hormones, and the expression of hormone-related genes (BnABF2, BnAOS, BnARF1, BnARR6, BnICS1, BnRGA, and BnWRKY57). Hormone concentrations in leaves changed dynamically in response to deacclimation with increased amounts of growth-promoting hormones and decreased amounts of stress hormones. Additionally, alterations in gene expression during deacclimation, such as in BnABF2 and BnICS1, may function as protective mechanisms to help maintain or regain frost tolerance during reacclimation when temperatures decline again after the warm period. These findings improve the understanding of hormonal and molecular responses involved in the deacclimation of oilseed rape. Full article

The response of plants to elevated atmospheric [CO₂] is highly dynamic and influenced by developmental stage, yet its role in photosynthetic acclimation remains underexplored. This study examines the physiological and molecular responses of wheat (Triticum durum, var. Amilcar) to elevated [CO₂] (700 ppm vs. 400 ppm) at two distinct developmental stages: the vegetative stage at the end of the elongation stage and the reproductive stage at the beginning of ear emergence (Z39 and Z51, respectively). Wheat plants at the developmental stage Z39, cultivated under elevated [CO₂], maintained photosynthetic rates despite a carbohydrate build-up. However, at Z51, photosynthetic acclimation became more evident as the decline in Rubisco carboxylation capacity (Vc_max) persisted, but also stomatal conductance and diffusion were decreased. This was accompanied by the up-regulation of the CA1 and CA2 genes, likely as a compensatory mechanism to maintain CO₂ supply. Additionally, hormonal adjustments under elevated [CO₂], including increased auxin and bioactive cytokinins (zeatin and isopentenyl adenine), may have contributed to delayed senescence and nitrogen remobilization, sustaining carbon assimilation despite biochemical constraints. These findings highlight the developmental regulation of photosynthetic acclimation, emphasizing the need for the stage-specific assessments of crop responses to future atmospheric conditions. Full article

Plants are continuously exposed to multiple environmental stressors throughout their lifecycle. Understanding their integrated physiological, biochemical, and anatomical responses under combined stress conditions is crucial for developing effective approaches to improve stress tolerance and maintain crop productivity. This study aimed to investigate the physiological, biochemical, and anatomical changes in photomorphogenic Micro-Tom plants exposed to high irradiance and water deficit—an abiotic stress combination that commonly co-occurs in natural environments but remains poorly understood in light-sensitive genotypes. We hypothesized that the high pigment 1 (hp1) mutant, due to its enhanced light responsiveness, would display improved stress acclimation compared to the wild-type when exposed to combined stress factors. This study was conducted in a controlled plant growth chamber, using a randomized block design with five replicates. Two Micro-Tom genotypes (wt and hp1) were exposed to control (soil at field capacity (FC) + 450 μmol m⁻² s⁻¹ PPFD) and combined stress (40% FC + 1800 μmol m⁻² s⁻¹ PPFD) conditions. Despite the higher concentration of chloroplast pigments in hp1, its photosynthetic performance under combined stress was not significantly improved, and its defense mechanisms did not effectively mitigate the stress impacts. Anatomically, wt exhibited greater structural adjustment, observed by adaptations in the spongy parenchyma and mesophyll. Overall, the wt genotype showed stronger defense mechanisms, while hp1 was more susceptible to combined abiotic stress. Full article

Heat stress (HS) in dairy cattle triggers systemic physiological disruptions, including milk yield decline, immune suppression, and reproductive dysfunction, jeopardizing sustainable livestock production. While conventional single-omics or phenotypic studies have provided fragmented insights, they fail to decipher the multi-layered regulatory networks and gene–environment interactions underlying HS. This review integrates current knowledge on HS-induced physiological responses and molecular adaptations in dairy cattle from a multi-omics perspective, highlighting integrative approaches that combine IoT-enabled monitoring and AI-driven genetic improvement strategies. However, key challenges persist, such as complexities in bioinformatic data integration, CRISPR off-target effects, and ethical controversies. Future directions will emphasize the development and application of AI-aided predictive models to enable precision breeding, thereby advancing climate-resilient genetic improvement in dairy cattle. Full article

Global climate change has intensified the heterogeneity of precipitation regimes in subtropical regions, and the increasing frequency of extreme drought events poses a significant threat to biogeochemical cycling in forest ecosystems. Yet, the pathways by which reduced precipitation regulates deadwood decomposition and thereby influences soil nutrient pools remain poorly resolved. Here, we investigated a Cunninghamia lanceolata (Lamb.) Hook. plantation in subtropical China under ambient precipitation (CK) and precipitation reduction treatments of 30%, 50%, and 80%, systematically examining how reduced precipitation alters the chemical properties of deadwood substrates and, in turn, soil nutrient status. Our findings reveal that (1) as precipitation declined, soil water content decreased significantly (p < 0.01), while deadwood pH declined and total organic carbon (TOC), nonstructural carbohydrates (NSCs), and lignin content markedly accumulated (p < 0.01); (2) these shifts in deadwood chemistry affected feedback mechanisms, leading to the suppression of soil nutrient pools: extreme drought (80% reduction) significantly reduced soil TOC, dissolved organic carbon (DOC), total nitrogen (TN), and total phosphorus (TP) (p < 0.01) and inhibited N and P mineralization, whereas the 30% reduction treatment elicited a transient increase in soil microbial biomass carbon (MBC), indicative of microbial acclimation to mild water stress; and (3) principal component analysis (PCA) showed that the 80% reduction treatment drove lignin accumulation in deadwood, while the 30% reduction treatment exerted the greatest influence on soil DOC, TOC, and MBC; partial least squares path modeling (PLS-PM) further demonstrated that soil water content and deadwood substrate properties (pH, lignin, soluble sugars, TOC, C/N, and lignin/N) were strongly negatively correlated (r = −0.9051, p < 0.01), and that deadwood chemistry was, in turn, negatively correlated with soil nutrient variables (pH, TOC, DOC, MBC, TP, TN, and dissolved organic nitrogen [DON]; r = −0.8056, p < 0.01). Together, these results indicate that precipitation reduction—by drying soils—profoundly modifies deadwood chemical composition (lignin accumulation and NSC retention) and thereby, via slowed organic-matter mineralization, constrains soil nutrient release and accumulation. This work provides a mechanistic framework for understanding forest carbon–nitrogen cycling under climate change. Full article

Declining freshwater resources have spurred interest in saline–alkali (SA) water aquaculture, with species like tilapia and rainbow trout demonstrating ecological plasticity in such environments. However, the molecular mechanisms underlying fish adaptation and quality impacts remain unclear. This study investigated the hybrid fish “Xianfeng No. 1” (Erythroculter ilishaeformis × Ancherythroculter nigrocauda), a key aquaculture species in China, under 60-day SA exposure. The results showed increased levels of oxidative stress markers (MDA) and antioxidant enzymes (SOD, CAT, GSH-Px), alongside improved quality traits. Transcriptomics revealed differentially expressed genes (DEGs) in muscle tissue associated with oxidative stress (UQCRFS1, UQCR10, CYC1), ion transport (COX5A, COX7C, COX7B), and the immune response (ATG9A, ATG2B, ATG2A, ULK1, ULK2, CFI, CFH). Metabolomics identified increased non-volatile flavors (e.g., glycine, proline) and collagen-related compounds. Integrated analysis highlighted the upregulation of GSR and GGT, and the downregulation of CHDH and GBSA, potentially driving glycine accumulation. These findings suggest that SA stress enhances antioxidant capacity, activates immune pathways, and modulates ion transport, enabling adaptation while improving meat quality. This study elucidates molecular mechanisms of fish acclimation to SA environments, providing insights for sustainable aquaculture development and breeding of stress-tolerant species in SA regions. Full article

The present study investigated the influence of a 30 day exposure of rainbow trout (Oncorhynchus mykiss) to a suboptimal low temperature of 1.8 ± 1.0 °C on their different gill characteristics (morphometry, enzyme activities, and expression of genes) in comparison to fish acclimated to 9.4 ± 0.1 °C. Morphometric analysis revealed a significant decrease in the distance between the secondary lamellae at the low temperature, which can be interpreted as a decrease in the effective gill surface. The epithelial thickness increased at the lower temperatures, which is considered a mechanism to reduce ion fluxes and save the energy costs for osmoregulation. The length of the primary lamellae, distance between the primary lamellae, length of the secondary lamellae, as well as the number of mucus cells, chloride cells, and capillaries per mm of the secondary lamella were similar between the temperature regimes. The enzymatic activities of pyruvate kinase and malate dehydrogenase were significantly increased in cold-exposed fish, whereas lactate dehydrogenase activity was higher in controls, indicating increased energy expenditure and adjustments in energy metabolism. The activities of carbonic anhydrase, caspase, Na⁺/K⁺ ATPase, and H⁺ ATPase, and the gene expressions of hif1a, ca2, rhCG, slc26a6, and slc9a1 showed no statistically significant differences between the two temperature regimes. Therefore, it can be concluded that ammonia transport, acid–base regulation, and osmoregulation were not affected by the tested low temperature regime. These findings highlight that exposure to suboptimal temperatures induces structural and metabolic modifications in rainbow trout gills, potentially as an adaptive response to thermal stress. This study contributes to the understanding of fish acclimation to cold environments, with implications for aquaculture and ecological resilience in changing climates. Full article

Light variability is a key environmental stressor influencing the physiology and productivity of marine macroalgae. This study examined the ecophysiological and biochemical responses of Lessonia spicata (Ochrophyta) during a natural light deprivation event caused by a solar eclipse. We measured the in vivo chlorophyll a (Chla) fluorescence, photoinhibition, and photosynthetic capacity, along with the pigment content, phenolic compound accumulation, and antioxidant capacity, to evaluate short-term photosynthetic adjustments. Dark-adapted conditions during the eclipse peak led to reduced photosynthetic and biochemical activity, while post-eclipse recovery involved the increased accumulation of photosynthetic pigments and photoprotective compounds. Carotenoids showed high antioxidant potential under eclipse exposure, contrasting with declines in chlorophyll content and productivity under pre-eclipse high irradiance. This study provides valuable insights into the rapid acclimation mechanisms of Lessonia spicata to transient light stress, highlighting its sensitivity and resilience to sudden shifts in solar irradiance. These findings contribute to the broader field of marine macroalgal photobiology and stress physiology, enhancing our understanding of how intertidal brown algae adapt to dynamic environmental conditions. Full article

While a rapid activation of antioxidant defense mechanisms following the exposure to salt stress has been widely reported in plants, less is known about their role under prolonged ionic stress conditions. This study aimed at investigating whether increased levels of enzymatic antioxidants are required in salt-acclimated plants. Rice, a staple crop for more than half of the world’s population, is very sensitive to excess salt, mainly at the seedling stage. The levels of selected antioxidant enzymes and the non-enzymatic antioxidant glutathione were measured in seedlings of a group of five Italian rice cultivars showing a natural variability in the susceptibility to a moderate saline environment. Up to 15.62 dS/m, the presence of salts caused a progressive growth inhibition, yet thiobarbituric acid reactive substance levels did not significantly increase. Accordingly, chlorophyll content appeared unaffected, suggesting successful acclimation. Immunological analysis showed increases of catalase protein levels in shoots, and of Cu/Zn- and Mn-dependent superoxide dismutases in both roots and shoots, whereas no variations were found for other enzymes. Only slight differences in glutathione content were evident between salt-grown seedlings and untreated controls. The data suggest that an enhancement of antioxidant defenses in different tissues takes place in rice plants to cope with sublethal salt stress conditions. Full article

Macrobrachium nipponense is an important economic freshwater species in China. Previous research has found that M. nipponense can reproduce under salinity conditions of 10 parts per thousand (ppt) and exhibits a strong ability to adapt to salinity changes in the aquatic environment. The aim of the present study was to identify the molecular mechanism of M. nipponense in terms of saline acclimation by identifying changes in immune response, morphology, and gene expression in the gills under a salinity of 10 ppt. The findings revealed that salinity exposure dramatically stimulated the activities of MDA, Ca²⁺Mg²⁺-ATPase, and CAT, reaching a peak on Day 7 (p < 0.05), indicating that these antioxidant enzymes play essential roles in protecting the body from the damage caused by saline treatment. In addition, we found no obvious morphological changes in the gills, indicating that M. nipponense can adapt well to water environments with such salinity. Transcriptome profiling analysis identified 168, 434, and 944 differentially expressed genes (DEGs) when comparing S0 vs. S1, S1 vs. S4, and S4 vs. S7, respectively. Furthermore, lysosome, apoptosis, amino sugar, and nucleotide sugar metabolism; the cGMP-PKG signaling pathway; pancreatic secretion; and the calcium signaling pathway represented the main enriched metabolic pathways of DEGs in the present study. Lysosome, apoptosis, amino sugar, and nucleotide sugar metabolism and the cGMP-PKG signaling pathway are immune-related metabolic pathways, while pancreatic secretion is an energy-metabolism-related metabolic pathway, suggesting that the immune response and energy metabolism play essential roles in the regulation of saline acclimation in this species. The results from the quantitative real-time PCR analyses of the DEGs were consistent with those from RNA-Seq, indicating the accuracy of the present study. This study provides valuable evidence for the acclimation of M. nipponense to high-salinity aquatic environments, thus indicating the potential for this species to be used in aquaculture programs in saline and alkaline water regions. Full article

Drought stress is a devastating natural stress that threatens crop productivity and quality. Mitigating the adverse effects of drought stress on wheat is a key object in agriculture. C-repeat binding transcription factor/DROUGHT RESPONSE ELEMENT BINDING FACTOR 1 (CBF/DREB1) transcription factors are well known for their role in cold acclimation. However, the involvement of CBF genes in drought stress and the mechanisms underlying their function remain poorly understood. In this study, 81 CBFs were identified in wheat, which were further clustered into four distinct lineages based on phylogenetic analysis. Chromosomal localization indicated that most CBF genes were dispersed across chromosome 5. We identified three homoeologous genes (TaCBF14A, TaCBF14B, and TaCBF14D) that were simultaneously upregulated under drought stress based on RNA-seq analysis. According to the high expression after drought stress, TaCBF14B was selected for further functional analysis. Subcellular localization and transcriptional activation activity analysis indicated that TaCBF14B likely functions as a transcription factor involved in drought stress tolerance. Overexpression of TaCBF14B in Arabidopsis enhanced the primary root growth by 13.49% (OE1), 12.56% (OE2), and 19.53% (OE3) under 200 mM mannitol treatment, and 21.65% (OE1), 16.63% (OE2), and 28.13% (OE3) under 250 mM mannitol treatment compared to WT. Meanwhile, the water loss rate of transgenic lines was 56% in WT leaves, but only 44%, 50%, and 40% in OE1, OE2, and OE3 lines, respectively. Compared to the wild type, POD activities of OE1, OE2, and OE3 were significantly increased by 42.94%, 29.41%, and 62.52%, respectively. And the Pro activities in OE1, OE2, and OE3 were significantly increased by 16.33%, 5.18%, and 29.09%, respectively, compared to the wild type. Additionally, the MDA content in OE1, OE2, and OE3 was significantly reduced by 40.53%, 15.81%, and 54.36%, respectively. Further analysis showed that the transgenic lines were hypersensitive to abscisic acid (ABA), and exhibited increased expression of AtABI3. We speculate that TaCBF14B plays an important role in enhancing drought tolerance. In summary, our findings provide new insights into the functional roles of CBF genes in drought stress tolerance. Full article

As arsenopyrite is a typical arsenic-bearing sulfide ore, the biooxidation process of arsenopyrite is of great significance for the extraction of gold from arsenic-bearing gold ores and the generation of arsenic-bearing acid mine drainage. During the biooxidation of arsenopyrite, a large amount of arsenic is produced, which inhibits the growth and metabolism of microorganisms and thus affects the extraction of gold from arsenic-bearing gold ores. Therefore, the screening and enrichment of microorganisms with high arsenic resistance have become important aspects in the study of arsenopyrite biooxidation. As described in this paper, through arsenic acclimation, the maximum arsenic tolerance concentration of Acidithiobacillus ferriphilus QBS 3 isolated from arsenic-containing acid mine drainage was increased to 80 mM As(Ⅲ) and 100 mM As(V). Microorganisms with high arsenic resistance showed better bioleaching performance for arsenopyrite. After 18 days of bioleaching, the leaching rate of arsenopyrite reached 100% at a pulp concentration of 0.5%, and after 30 days of bioleaching, the leaching rate of arsenopyrite was 79.96% at a pulp concentration of 1%. Currently, research on arsenopyrite mainly focuses on the control and optimization of environmental conditions, but there have been few studies on the biooxidation process of arsenopyrite at the protein and gene levels. Therefore, combining the results of a one-month bioleaching experiment on arsenopyrite by A. ferriphilus QBS 3 and the analysis of arsenic resistance genes, a bioleaching model of arsenopyrite was constructed, which laid an experimental basis and theoretical foundation for improving the gold recovery rate from refractory arsenic-bearing ores and exploring the arsenic resistance mechanism of microorganisms during the arsenopyrite leaching process. Full article

Plants continuously adapt to their environments by responding to various intrinsic and extrinsic signals. They face numerous biotic and abiotic stresses such as extreme temperatures, drought, or pathogens, requiring complex regulatory mechanisms to control gene activity and adapt their proteome for survival. Epigenetic regulation plays a crucial role in these adaptations, potentially leading to both heritable and non-heritable changes across generations. This process enables plants to adjust their gene expression profiles and acclimate effectively. It is also vital for plant development and productivity, affecting growth, yield, and seed quality, and enabling plants to “remember” environmental stimuli and adapt accordingly. Key epigenetic mechanisms that play significant roles include DNA methylation, histone modification, and ubiquitin ligase complex activity. These processes, which have been extensively studied in the last two decades, have led to a better understanding of the underlying mechanisms and expanded the potential for improving agriculturally and economically important plant traits. DNA methylation is a fundamental process that regulates gene expression by altering chromatin structure. The addition of methyl groups to cytosines by DNA methylases leads to gene suppression, whereas DNA demethylases reverse this effect. Histone modifications, on the other hand, collectively referred to as the “histone code”, influence chromatin structure and gene activity by promoting either gene transcription or gene silencing. These modifications are either recognized, added, or removed by a variety of enzymes that act practically as an environmental memory, having a significant impact on plant development and the responses of plants to environmental stimuli. Finally, ubiquitin ligase complexes, which tag specific histones or regulatory proteins with ubiquitin, are also crucial in plant epigenetic regulation. These complexes are involved in protein degradation and play important roles in regulating various cellular activities. The intricate interplay between DNA methylation, histone modifications, and ubiquitin ligases adds complexity to our understanding of epigenetic regulation. These mechanisms collectively control gene expression, generating a complex and branching network of interdependent regulatory pathways. A deeper understanding of this complex network that helps plants adapt to environmental changes and stressful conditions will provide valuable insights into the regulatory mechanisms involved. This knowledge could pave the way for new biotechnological approaches and plant breeding strategies aimed at enhancing crop resilience, productivity, and sustainable agriculture. Full article

The median lethal concentration value of alkalinity tolerance for Macrobrachium nipponense over 96 h is only 14.42 mmol/L with a safety value of 4.71 mmol/L, which is insufficient to perform the aquaculture program in a water environment with high alkalinity. Thus, the present study aims to explore the effects of alkalinity exposure on the gills of M. nipponense through identifying the changes in antioxidant enzymes, morphology, and gene expressions after 1 day, 4 days, and 7 days of exposure under an alkalinity of 10 mmol/L. The activities of MDA, GSH-PX, CAT, T-AOC, and Ca²⁺Mg²⁺-ATPase are significantly stimulated by 62.6%, 6.57%, 32.1%, 33.3%, and 14.9%, compared to those from Day 0 (control group), indicating that these antioxidant enzymes play essential roles in the protection of prawns from the damage of reactive oxygen species caused by alkalinity exposure. In addition, alkalinity exposure results in an increase in the hemolymph vessels, affecting the normal respiratory function of the gills. Transcriptome profiling analysis reveals that short-term alkali exposure (4 days) does not result in significant changes in gene expression in the present study. Furthermore, metabolic pathways, biosynthesis of amino acids, amino sugar and nucleotide sugar metabolism, lysosomes, glycolysis/gluconeogenesis, and phagosomes represent the main enriched metabolic pathways of differentially expressed genes (DEGs) between Day 4 and Day 7. Biosynthesis of amino acids, lysosomes, and phagosomes are immune-related metabolic pathways, while amino sugar and nucleotide sugar metabolism and glycolysis/gluconeogenesis are energy metabolism-related metabolic pathways, indicating that the processes of immune response and energy metabolism play essential roles in the response to alkalinity exposure in M. nipponense. Thus, the DEGs from these metabolic pathways are considered as candidate genes involved in the regulation of alkaline acclimation in M. nipponense. The present study provides valuable evidence for analysis of the adaptive mechanism when exposed to alkalinity, contributing to the survival rate and aquaculture of this species under water environments with high alkalinity. Full article