Search Results (1,576)

Freshwater salinization, an escalating global environmental stressor, poses a significant threat to freshwater biodiversity, including fish communities. This study investigates the grass carp (Ctenopharyngodon idellus), a species with the highest aquaculture output in China, to elucidate the molecular underpinnings of its physiological adaptations to fluctuating salinity gradients. We used high-throughput mRNA sequencing and differential gene expression profiling to analyze transcriptional dynamics in intestinal and kidney tissues of grass carp exposed to heterogeneous salinity stressors. Concurrent serum biochemical analyses showed salinity stress significantly increased Na⁺, Cl⁻, and osmolarity, while decreasing lactate and glucose. Salinity stress exerted a profound impact on the global transcriptomic landscape of grass carp. A substantial number of co-regulated differentially expressed genes (DEGs) in kidney and intestinal tissues were enriched in immune and metabolic pathways. Specifically, genes associated with antigen processing and presentation (e.g., cd4-1, calr3b) and apoptosis (e.g., caspase17, pik3ca) exhibited upregulated expression, whereas genes involved in gluconeogenesis/glycolysis (e.g., hk2, pck2) were downregulated. KEGG pathway enrichment analyses revealed that metabolic and cellular structural pathways were predominantly enriched in intestinal tissues, while kidney tissues showed preferential enrichment of immune and apoptotic pathways. Rigorous validation of RNA-seq data via qPCR confirmed the robustness and cross-platform consistency of the findings. This study investigated the core transcriptional and physiological mechanisms regulating grass carp’s response to salinity stress, providing a theoretical foundation for research into grass carp’s resistance to salinity stress and the development of salt-tolerant varieties. Full article

Since the onset of industrialization, the safety of arable land has become a pressing global concern, with soil salinization emerging as a critical threat to agricultural productivity and food security. To address this challenge, the cultivation of economically valuable salt-tolerant plants has been proposed as a viable strategy. In the study, we investigated the physiological and molecular responses of Lycium ruthenicum Murr. to varying NaCl concentrations. Results revealed a concentration-dependent dual effect: low NaCl levels significantly promoted seed germination, while high concentrations exerted strong inhibitory effects. To elucidate the mechanisms underlying these divergent responses, a combined analysis of metabolomics and transcriptomics was applied to identify key metabolic pathways and genes. Notably, salt stress enhanced photosynthetic efficiency through coordinated modulation of ribulose 5-phosphate and erythrose-4-phosphate levels, coupled with the upregulation of critical genes encoding RPIA (Ribose 5-phosphate isomerase A) and RuBisCO (Ribulose-1,5-bisphosphate carboxylase/oxygenase). Under low salt stress, L. ruthenicum maintained intact cellular membrane structures and minimized oxidative damage, thereby supporting germination and early growth. In contrast, high salinity severely disrupted PS I (Photosynthesis system I) functionality, blocking energy flow into this pathway while simultaneously inducing membrane lipid peroxidation and triggering pronounced cellular degradation. This ultimately suppressed seed germination rates and impaired root elongation. These findings suggested a mechanistic framework for understanding L. ruthenicum adaptation under salt stress and pointed out a new way for breeding salt-tolerant crops and understanding the mechanism. Full article

Soil salinization is a major constraint to global crop productivity, highlighting the need to identify salt tolerance genes and their molecular mechanisms. Here, we integrated mRNA and miRNA profile analyses to investigate the molecular basis of salt tolerance of an elite Brassica napus cultivar S268. Time-course RNA-seq analysis revealed dynamic transcriptional reprogramming under 215 mM NaCl stress, with 212 core genes significantly enriched in organic acid degradation and glyoxylate/dicarboxylate metabolism pathways. Combined with weighted gene co-expression network analysis (WGCNA) and RT-qPCR validation, five candidate genes (WRKY6, WRKY70, NHX1, AVP1, and NAC072) were identified as the regulators of salt tolerance in rapeseed. Haplotype analysis based on association mapping showed that NAC072, ABI5, and NHX1 exhibited two major haplotypes that were significantly associated with salt tolerance variation under salt stress in rapeseed. Integrated miRNA-mRNA analysis and RT-qPCR identified three regulatory miRNA-mRNA pairs (bna-miR160a/BnaA03.BAG1, novel-miR-126/BnaA08.TPS9, and novel-miR-70/BnaA07.AHA1) that might be involved in S268 salt tolerance. These results provide novel insights into the post-transcriptional regulation of salt tolerance in B. napus, offering potential targets for genetic improvement. Full article

Sunflower (Helianthus annuus L.) is an important oilseed crop in Northwest China, exhibiting resistance to salt and drought. Mining its excellent tolerance genes can be used for breeding. However, the current platforms for identifying gene function in sunflower is inadequate. The transient transformation system, which can rapidly validate gene function, shows promising prospects in research. In this study, we established an efficient transient expression transformation system for sunflower using three methods: Agrobacterium-mediated infiltration, injection, and ultrasonic-vacuum. The detailed procedures were as follows: Agrobacterium GV3101 carrying a GUS reporter gene on the pBI121 vector with an OD₆₀₀ of 0.8 as the bacterial suspension and 0.02% Silwet L-77 as the surfactant were utilized in all three approaches. For the infiltration method, seedlings grown hydroponically for 3 days were immersed in a bacterial suspension containing 0.02% Silwet L-77 for 2 h; for the injection method, the same solution was injected into the cotyledons of seedlings grown in soil for 4 to 6 days. Subsequently, the seedlings were cultured in the dark at room temperature for three days; for the ultrasonic-vacuum method, seedlings cultured in Petri dishes for 3 days were first subjected to ultrasonication at 40 kHz for 1 min, followed by vacuum infiltration at 0.05 kPa for 5–10 min. Agrobacterium-mediated transient transformation efficiency achieved by the three methods exceeded 90%, with gene expression being sustained for at least 6 days. Next, we employed the infiltration-based sunflower transient transformation technology with the Arabidopsis stable transformation platform to confirm salt and drought stress tolerance of candidate gene HaNAC76 from sunflower responding to various abiotic stresses. Altogether, this study successfully established an Agrobacterium-mediated transient transformation system for sunflower using these three methods, which can rapidly identify gene function and explore the molecular mechanisms underlying sunflower’s resistance traits. Full article

Soil salinization constitutes a major constraint on global agricultural production, with marked divergence in salt adaptation strategies between salt-tolerant barley (Hordeum vulgare) and salt-sensitive rice (Oryza sativa). This study systematically investigated the evolution and functional specialization of the C3HC4-type RING zinc finger gene family, known to mediate abiotic stress responses through E3 ubiquitin ligase activity, in these contrasting cereal species. Through comparative genomics, we identified 123 HvC3HC4 genes and 90 OsC3HC4 genes, phylogenetically classified into four conserved subgroups. Differences in C3HC4 genes in phylogenetic relationships, chromosomal distribution, gene structure, motif composition, gene duplication events, and cis-elements in the promoter region were observed between barley and rice. Moreover, HvC3HC4s in barley tissues preferentially adopted an energy-conserving strategy, which may be a key mechanism for barley’s higher salt tolerance. Additionally, we found that C3HC4 genes were evolutionarily conserved in salt-tolerant species. The current results reveal striking differences in salt tolerance between barley and rice mediated by the C3HC4 gene family and offer valuable insight for potential genetic engineering applications in improving crop resilience to salinity stress. Full article

In this study, 62 lactic acid bacteria (LAB) strains were isolated from raw camel milk and evaluated for their probiotic potential. The strains exhibited significant variability in their ability to withstand simulated gastrointestinal conditions. Of the isolates, only 26 survived exposure to pH 2, and just 10 were tolerant to 0.3% bile salts. Partial sequencing of the 16S rRNA gene identified all the strains as belonging to the species Enterococcus faecium. Several probiotic traits were assessed, including adhesion to gastric mucin and STC-1 intestinal epithelial cells, as well as auto-aggregation and co-aggregation capacities. Although adhesion to hydrophobic solvents such as chloroform and ethyl acetate was generally low to moderate, all the strains demonstrated strong adhesion to gastric mucin, exceeding 60% at all the growth stages. Notably, two strains—SCC1-33 and SLch6—showed particularly high adhesion to STC-1 cells, with values of 7.8 × 10³ and 4.2 × 10³ CFU/mL, respectively. The strains also exhibited promising aggregation properties, with auto-aggregation and co-aggregation ranging between 33.10% and 63.10%. Furthermore, all the isolates displayed antagonistic activity against Listeria innocua, Micrococcus luteus, and Escherichia coli. Cytotoxicity assays confirmed that none of the tested strains had harmful effects on STC-1 cells, indicating their safety and supporting their potential application as probiotics. Full article

Soil salinity adversely affects crop growth and development, leading to reduced soil fertility and agricultural productivity. The indigenous salt-tolerant plant growth-promoting rhizobacteria (PGPR), as a sustainable microbial resource, do not only promote growth and alleviate salt stress, but also improve the soil microecology of crops. The strain H5 isolated from saline-alkali soil in Bachu of Xinjiang was studied through whole-genome analysis, functional annotation, and plant growth-promoting, salt-tolerant trait gene analysis. Phylogenetic tree analysis and 16S rDNA sequencing confirmed its classification within the genus Halomonas. Functional annotation revealed that the H5 genome harbored multiple functional gene clusters associated with plant growth promotion and salt tolerance, which were critically involved in key biological processes such as bacterial survival, nutrient acquisition, environmental adaptation, and plant growth promotion. The pot experiment under moderate salt stress demonstrated that seed inoculation with Halomonas sp. H5 not only significantly improved the agronomic traits of tomato seedlings, but also increased plant antioxidant enzyme activities under salt stress. Additionally, soil analysis revealed H5 treatment significantly decreased the total salt (9.33%) and electrical conductivity (8.09%), while significantly improving organic matter content (11.19%) and total nitrogen content (10.81%), respectively (p < 0.05). Inoculation of strain H5 induced taxonomic and functional shifts in the rhizosphere microbial community, increasing the relative abundance of microorganisms associated with plant growth-promoting and carbon and nitrogen cycles, and reduced the relative abundance of the genera Alternaria (15.14%) and Fusarium (9.76%), which are closely related to tomato diseases (p < 0.05). Overall, this strain exhibits significant potential in alleviating abiotic stress, enhancing growth, improving disease resistance, and optimizing soil microecological conditions in tomato plants. These results provide a valuable microbial resource for saline soil remediation and utilization. Full article

Background: Anoectochilus roxburghii (Wall.) Lindl. (A. roxburghii) was widely used in traditional Chinese medicine and also as a health food in China. Gibberellins (GAs) are plant hormones that regulate various aspects of growth and development in A. roxburghii. Ent-kaurene synthase (KS) plays a crucial role in the biosynthesis of GAs in plants. However, there is limited functional analysis of KS in GA biosynthesis and its effect on salt tolerance, especially in A. roxburghii. Methods: The ArKS genes were cloned from A. roxburghii, and its salt tolerance characteristics were verified by prokaryotic expression. Under salt stress, analyze the regulation of KS gene on GA and active ingredient content by qRT-PCR and HPLC-MS/MS, and explore the mechanism of exogenous GAs promoting active ingredient enrichment by regulating the expression level of the KS under salt stress. Results: The ArKS protein was highly homologous to KSs with other plant species; subcellular localization of KS protein was lacking kytic vacuole. The transformants displayed a significant increase in salt tolerance under the stress conditions of 300 mM NaCl. And the expression of ArKS genes and the GAs accumulation was downregulated under the salt stress; among them, the contents of GA3, GA7, GA8, GA24, and GA34 showed a significant decrease. It was further found that there was an increase (1.36 times) in MDA content and a decrease (0.84 times) in relative chlorophyll content under the salt conditions from A. roxburghii. However, the content of active constituents was elevated from A. roxburghii under the NaCl stress, including polysaccharides, total flavonoids, and free amino acids, which increased by 1.14, 1.23, and 1.44 times, respectively. Interestingly, the ArKS gene expression and the chlorophyll content was increased, MDA content showed a decrease from 2.02 μmoL·g⁻¹ to 1.74 μmoL·g⁻¹ after exogenous addition of GAs, and the elevation of active constituents of polysaccharides, total flavonoids, and free amino acids were increased by 1.02, 1.09, and 1.05 times, implying that GAs depletion mitigated the damage caused by adversity to A. roxburghii. Conclusions: The ArKS gene cloned from A. roxburghii improved the salt tolerance of plants under salt stress by regulating GA content. Also, GAs not only alleviate salt tolerance but also play a key role in the synthesis of active components in A. roxburghii. The functions of KS genes and GAs were identified to provide ideas for improving the salt tolerance and quality of ingredients in artificial cultivation from A. roxburghii. Full article

Fructose-1,6-bisphosphate aldolase (FBA; EC 4.1.2.13) is a key enzyme in glycolysis and the Calvin cycle, which plays crucial roles in carbon allocation and plant growth. The FBA family genes (FBA s) have been identified in several plants. However, their presence and roles in sweet potato remain unexplored. In this study, a total of 20 FBAs were identified in sweet potato and its wild wild diploidrelatives, including seven in sweet potato (Ipomoea batatas, 2n = 6x = 90), seven in I. trifida (2n = 2x = 30), and six in I. triloba (2n = 2x = 30). Their protein physicochemical properties, chromosomal localization, phylogenetic relationship, gene structure, promoter cis-elements, and expression patterns were systematically analyzed. The conserved genes and protein structures suggest a high degree of functional conservation among FBA genes. IbFBAs may participate in storage root development and starch biosynthesis, especially IbFBA1 and IbFBA6, which warrant further investigation as candidate genes. Additionally, the FBAs could respond to drought and salt stress. They are also implicated in hormone crosstalk, particularly with ABA and GA. This work provides valuable insights into the structure and function of FBAs and identifies candidate genes for improving yield, starch content, and abiotic stress tolerance in sweet potatoes. Full article

Stipagrostis pennata is an important plant in desert ecosystems. Its seed-endophytic bacteria may play a critical role in plant growth and environmental adaptation processes. This study systematically analyzed the community composition and potential plant growth-promoting (PGP) functions of seed-endophytic bacteria associated with S. pennata. The results showed that while the overall diversity of bacterial communities from different sampling sites was similar, significant differences were observed in specific functional genes and species abundances. Nine endophytic bacterial strains were isolated from the seeds, among which Bacillus altitudinis strain L7 exhibited phosphorus solubilizing capabilities, nitrogen fixing, IAA production, siderophore generation, and multi-hydrolytic enzyme activities. Additionally, the genomic sequencing of L7 revealed the key genes involved in plant growth promotion and environmental adaptation, including Na⁺ efflux systems, K⁺ transport systems, compatible solute synthesis genes, and the gene clusters associated with nitrogen metabolism, IAA synthesis, phosphate solubilization, and siderophore synthesis. Strain L7 exhibits salt and osmotic stress tolerance while promoting plant growth, providing a promising candidate for desert microbial resource utilization and plant biostimulant development. Full article

GOLDEN2-LIKEs (GLKs) are important transcription factors for the chloroplast development influencing photosynthesis, nutrition, senescence, and stress response in plants. Sunflower (Helianthus annuus) is a highly photosynthetic plant; here, a GLK-homologues gene HaGLK was identified from the sunflower genome by bioinformatics. To analyze the bio-function of HaGLK, transgenic rice plants overexpressing HaGLK (HaGLK-OE) were constructed and characterized via phenotype. Compared to the wild-type control rice variety Zhonghua 11 (ZH11), the HaGLK-OE lines exhibited increased photosynthetic pigment contents, higher net photosynthetic rates, and enlarged chloroplast area; meanwhile, genes involved in both photosynthesis and chlorophyll biosynthesis were also significantly up-regulated. Significantly, the HaGLK-OE plants showed a 12–13% increase in yield per plant. Additionally, the HaGLK-OE plants were demonstrated to have improved salt and drought tolerance compared to the control ZH11. Our results indicated that the HaGLK gene could play multiple roles in photosynthesis and stress response in rice, underscoring its potential value for improving crop productivity and environmental adaptability in breeding. Full article

The worldwide agriculture industry is facing increasing problems due to rapid population increase and increasingly unfavorable weather patterns. In order to reach the projected food production targets, which are essential for guaranteeing global food security, innovative and sustainable agricultural methods must be adopted. Conventional approaches, including traditional breeding procedures, often cannot handle the complex and simultaneous effects of biotic pressures such as pest infestations, disease attacks, and nutritional imbalances, as well as abiotic stresses including heat, salt, drought, and heavy metal toxicity. Applying phytohormonal approaches, particularly those involving hormonal crosstalk, presents a viable way to increase crop resilience in this context. Abscisic acid (ABA), gibberellins (GAs), auxin, cytokinins, salicylic acid (SA), jasmonic acid (JA), ethylene, and GA are among the plant hormones that control plant stress responses. In order to precisely respond to a range of environmental stimuli, these hormones allow plants to control gene expression, signal transduction, and physiological adaptation through intricate networks of antagonistic and constructive interactions. This review focuses on how the principal hormonal signaling pathways (in particular, ABA-ET, ABA-JA, JA-SA, and ABA-auxin) intricately interact and how they affect the plant stress response. For example, ABA-driven drought tolerance controls immunological responses and stomatal behavior through antagonistic interactions with ET and SA, while using SnRK2 kinases to activate genes that react to stress. Similarly, the transcription factor MYC2 is an essential node in ABA–JA crosstalk and mediates the integration of defense and drought signals. Plants’ complex hormonal crosstalk networks are an example of a precisely calibrated regulatory system that strikes a balance between growth and abiotic stress adaptation. ABA, JA, SA, ethylene, auxin, cytokinin, GA, and BR are examples of central nodes that interact dynamically and context-specifically to modify signal transduction, rewire gene expression, and change physiological outcomes. To engineer stress-resilient crops in the face of shifting environmental challenges, a systems-level view of these pathways is provided by a combination of enrichment analyses and STRING-based interaction mapping. These hormonal interactions are directly related to the United Nations Sustainable Development Goals (SDGs), particularly SDGs 2 (Zero Hunger), 12 (Responsible Consumption and Production), and 13 (Climate Action). This review emphasizes the potential of biotechnologies to use hormone signaling to improve agricultural performance and sustainability by uncovering the molecular foundations of hormonal crosstalk. Increasing our understanding of these pathways presents a strategic opportunity to increase crop resilience, reduce environmental degradation, and secure food systems in the face of increasing climate unpredictability. Full article

Excavating new salt tolerance genes and utilizing them to improve salt-tolerant wheat varieties is an effective way to utilize salinized soil. The NAC gene family plays an important role in plant response to salt stress. In this study, 446 NAC sequences were isolated from the whole genome of common wheat and classified into 118 members based on subgenome homology, named TaNAC1 to TaNAC118. Transcriptome analysis of salt-tolerant wheat breeding line CH7034 roots revealed that 144 of the 446 TaNAC genes showed significant changes in expression levels at least two time points after NaCl treatment. These differentially expressed TaNACs were divided into four groups, and Group 4, containing the largest number of 78 genes, exhibited a successive upregulation trend after salt treatment. Single nucleotide polymorphisms (SNPs) of the TaNAC gene family in 114 wheat germplasms were retrieved from the public database and were subjected to further association analysis with the relative salt-injury rates (RSIRs) of six root phenotypes, and then 20 SNPs distributed on chromosomes 1B, 2B, 2D, 3B, 3D, 5B, 5D, and 7A were correlated with phenotypes involving salt tolerance (p < 0.0001). Combining the results of RT-qPCR and association analysis, we further selected three NAC genes from Group 4 as candidate genes that related to salt tolerance, including TaNAC26-D3.2, TaNAC33-B, and TaNAC40-B. Compared with the wild type, the roots of the tanac26-d3.2 mutant showed shorter length, less volume, and reduced biomass after being subjected to salt stress. Four SNPs of TaNAC26-D3.2 formed two haplotypes, Hap1 and Hap2, and germplasms with Hap2 exhibited better salt tolerance. Snp3, in exon 3 of TaNAC26-D3.2, causing a synonymous mutation, was developed into a Kompetitive Allele-Specific PCR marker, K3, to distinguish the two haplotypes, which can be further used for wheat germplasm screening or marker-assisted breeding. This study provides new genes and molecular markers for improvement of salt tolerance in wheat. Full article

Asia minor bluegrass (Polypogon fugax), a widespread Poaceae weed, exhibits broad tolerance to abiotic stresses. Validated reference genes (RGs) for reliable RT-qPCR normalization in this ecologically and agriculturally significant species remain unidentified. This study identified eight candidate RGs using transcriptome data from seedling tissues. We assessed the expression stability of these eight RGs across various abiotic stresses and developmental stages using Delta Ct, BestKeeper, geNorm, and NormFinder algorithms. A comprehensive stability ranking was generated using RefFinder, with validation performed using the target genes COR413 and P5CS. Results identified EIF4A and TUB as the optimal RG combination for normalizing gene expression during heat stress, cold stress, and growth stages. EIF4A and ACT were most stable under drought stress, EIF4A and 28S under salt stress, and EIF4A and EF-1 under cadmium (Cd) stress. Furthermore, EIF4A and UBQ demonstrated optimal stability under herbicide stress. Additionally, application of validated RGs revealed higher acetyl-CoA carboxylase gene (ACCase) expression in one herbicide-resistant population, suggesting target-site gene overexpression contributes to resistance. This work presents the first systematic evaluation of RGs in P. fugax. The identified stable RGs provide essential tools for future gene expression studies on growth and abiotic stress responses in this species, facilitating deeper insights into the molecular basis of its weediness and adaptability. Full article

Combined abiotic stresses often impose greater challenges to plant survival than individual stresses. In this study, we focused on elucidating the physiological and molecular mechanisms underlying the response of Dendrobium huoshanense to combined salt and heat stress by integrating physiological, transcriptomic, and metabolomic analyses. Our results demonstrated that high temperature plays a dominant role in the combined stress response. Physiological assays showed increased oxidative damage under combined stress, accompanied by significant activation of antioxidant enzyme systems (SOD, POD, CAT). Metabolomic analysis revealed significant enrichment of glutathione metabolism and flavonoid biosynthesis pathways, with key antioxidants such as glutathione and naringenin chalcone accumulating under combined stress. Transcriptomic data supported these findings, showing differential regulation of stress-related genes, including those involved in reactive oxygen species scavenging and secondary metabolism. These results highlight a coordinated defense strategy in D. huoshanense, involving both enzymatic and non-enzymatic antioxidant systems to maintain redox homeostasis under combined stress. This study provides novel insights into the molecular mechanisms underlying combined stress tolerance and lays the foundation for improving stress resilience in medicinal orchids. Full article