Search Results (857)

Soil salinization has seriously restricted the growth of crops and the sustainable use of land resources. The exploitation and utilization of saline land has become an urgent problem of agricultural development and environmental management. Medicinal plants have “stress effect”, and some adversity stresses often become positive regulators of their quality, which provides new ideas for the development and utilization of saline land. Based on it, this review summarizes the adaptive mechanism of plants under saline stress, including the construction of plant phenotypic characteristics, osmotic regulation, ion homeostasis, and hormone regulation. We also outline management strategies for saline land, primarily encompassing physical, chemical, biological, and comprehensive improvements. We further discuss the prospects for the development and utilization of Chinese herbal medicines in saline land based on the resources of salt-tolerant medicinal plants and the effects of saline stress on the quality of Chinese herbal medicines, with a view to providing references for the improvement and utilization of saline land, as well as the solution of the dilemma of medicinal plants competing for land with grains. Full article

Cold stress significantly impairs plant growth and development, making the study of cold resistance mechanisms a critical research focus. Oreorchis patens (Lindl.) exhibits strong cold hardiness, yet its molecular and physiological adaptations to cold stress remain unclear. This study utilized microscopy, physiological assays, and RNA sequencing to comprehensively investigate O. patens’s responses to cold stress. The results reveal that cold stress altered leaf anatomy, leading to irregular mesophyll cells, deformed chloroplasts, and variable epidermal thickness. Physiologically, SOD and POD activities peaked at 5 °C/−10 °C, while CAT activity declined; osmotic regulators (soluble sugars, proline) increased with decreasing temperatures. Compared to the reference plants (e.g., Erigeron canadensis, Allium fistulosum), O. patens exhibited lower SOD and POD but markedly higher CAT activities, alongside reduced MDA, soluble sugars, proline, and proteins, underscoring its distinctive tolerance strategy. Low temperature stress (≤10 °C/5 °C) significantly decreased the SPAD index; the net photosynthetic rate (Pn) initially increased and then approached zero within the temperature range from 30 °C/25 °C to 25 °C/20 °C; transpiration rate (Tr) and stomatal conductance (Gs) changed synchronously, accompanied by an increase in intercellular CO₂ concentration (Ci). RNA sequencing identified 1139 cold-responsive differentially expressed genes, which were primarily enriched in flavonoid/lignin biosynthesis, jasmonic acid synthesis, and ROS scavenging pathways. qRT-PCR analysis revealed the role of secondary metabolites in O. patens response to cold stress. This study was the first to discuss the physiological, biochemical, and molecular regulatory mechanisms of O. patens resistance to cold stress, which provides foundational insights into its overwintering mechanisms and informs breeding strategies for cold-hardy horticultural crops in northern China. Full article

Porcine blood polypeptide (PBP) has been reported to play roles in plant growth. However, its functions in alleviating salt stress in wheat remain unclear. The present study was conducted to investigate the physiological and biochemical mechanisms underlying the effects of PBP on wheat salt tolerance. Morphological analysis showed that PBP-primed seedlings exhibited improved growth performance, significantly greater biomass accumulation, and enhanced root system development. Physiological assessments showed that primed seedlings displayed higher values of Pn, Gs, Tr, Fv/Fm, Fv′/Fm′, Φ_PSII, and NPQ, along with increased contents of total chlorophyll, Pro, TSS, and RWC. In addition, the activities of antioxidant enzymes, including SOD, CAT, POD, and APX, were significantly elevated, whereas the levels of H₂O₂, O₂⁻, MDA, and REC were significantly reduced. PCA indicated that antioxidant enzyme activity, osmotic regulation, and ROS accumulation were the major factors associated with the PBP-mediated salt stress response. Furthermore, qRT-PCR analysis suggested that exogenous PBP might enhance wheat salt tolerance by coordinately modulating multiple molecular mechanisms. Taken together, this study broadens the potential applications of PBP by demonstrating its capacity to improve wheat salt tolerance. Full article

Drought stress is a major constraint to cassava productivity, especially in drought-prone regions. Although cassava is considered drought-tolerant, prolonged or severe water scarcity significantly reduces tuber yield, carbon assimilation capacity and overall plant growth. The development, selection and deployment of cassava genotypes with enhanced drought tolerance and water use efficiency (WUE) will help to achieve food security. The ability of cassava genotypes to maintain productivity under drought stress is enhanced by drought-responsive genes that regulate stress-related proteins and metabolites, contributing to stomatal closure, osmotic adjustment, antioxidant defense, and efficient carbon assimilation. Therefore, this comprehensive review aimed to document: (i) the effects of drought stress on cassava’s physiological, biochemical and agronomic traits, and (ii) the mitigation strategies and breeding technologies that can improve cassava yield production, drought tolerance and WUE. The key traits discussed include stomatal regulation, chlorophyll degradation, source–sink imbalance, root system architecture and carbon allocation dynamics. In addition, the review presents advances in genomic, proteomic and metabolomic tools, and emphasizes the role of early bulking genotypes, drought tolerance indices, and multi-trait selection in developing cassava cultivars with enhanced drought tolerance, drought escape and drought avoidance mechanism. Therefore, the integration of these strategies will accelerate the development, selection and deployment of improved cassava varieties, which contribute to sustainable productivity and global food security under climate change. Full article

Maize is a globally vital crop for both grain and forage production. Its cultivation and growth are significantly restricted by salt stress. Expansins are non-enzymatic plant cell wall proteins that play pivotal roles in growth, development, and stress responses by mediating cell wall loosening. We identified ZmEXPA6, an α-expansin gene, as exhibiting high expression levels in maize roots under salt stress. In this study, the ZmEXPA6 gene was cloned and functionally characterized. Heterologous overexpression of ZmEXPA6 promoted root elongation and enhanced salt tolerance of Arabidopsis thaliana. Under salt stress, the ZmEXPA6 overexpression lines exhibited elevated levels of anthocyanin (61.70%, 59.70%), proline (16.39%, 15.11%), soluble sugars (11.97%, 8.68%), and soluble proteins (14.83%, 13.74%) compared to the WT. Concurrently, the expression of genes associated with anthocyanin and proline biosynthesis was markedly up-regulated in these overexpression lines. The ZmEXPA6 overexpression lines exhibited elevated activities of SOD (23.81%, 23.51%), CAT (13.86%, 10.93%), and POD (4.27%, 1.39%) compared to the WT, along with significantly reduced accumulation of MDA (23.47%, 24.48%), O₂⁻ (21.9%, 19.8%), and H₂O₂ (27.61%, 18.07%). These results indicate that ZmEXPA6 is involved in the growth and development of Arabidopsis thaliana and improves its salt tolerance through enhanced osmotic adjustment and elevated antioxidant capacity. Full article

This study aimed to elucidate the physiological, biochemical, and transcriptional regulatory responses of potato plants to iron deficiency stress. Two potato varieties were selected for analysis: 05P (high tuber iron content) and CI5 (low tuber iron content). Tissue culture seedlings of both varieties were subjected to iron deficiency, and the effects on stem length, root length, fresh weight, soluble sugar and protein contents, as well as the activities of superoxide dismutase (SOD), peroxidase (POD), malondialdehyde (MDA), and leaf chlorophyll content (SPAD) values were evaluated. Additionally, the impact of iron deficiency on zinc (Zn), magnesium (Mg), calcium (Ca), manganese (Mn), and copper (Cu) concentrations in different tissues were analyzed. Transcriptomic sequencing and quantitative real-time PCR (qRT-PCR) were performed on various seedling tissues. The results showed that iron deficiency significantly inhibited seedling growth and development, resulting in reduced plant height and fresh weight, increased root length, decreased leaf SPAD content, and elevated soluble sugar and protein concentration. SOD, POD, and MDA activities were also significantly increased. Elemental analysis revealed that iron deficiency enhanced the uptake and accumulation of Zn, Mg, Ca, Mn, and Cu across different tissues. Transcriptomic analysis identified differentially expressed genes (DEGs) significantly enriched in pathways related to photosynthesis, carbon metabolism, and ribosome function in roots, stems, and leaves. Iron deficiency induced the upregulation of H⁺-ATPase genes in roots (PGSC0003DMG400004101, PGSC0003DMG400033034), acidifying the rhizosphere to increase active iron availability. Subsequently, this was followed by the upregulation of FRO genes (PGSC0003DMG400000184, PGSC0003DMG400010125, PGSC0003DMG401009494, PGSC0003DMG401018223), which reduce Fe³⁺ to Fe²⁺, and activation of IRT genes, facilitating Fe²⁺ transport to various tissues. Iron deficiency also reduced SPAD content in leaves, negatively impacting photosynthesis and overall plant growth. In response, the osmotic regulation and antioxidant defense systems were activated, enabling the plant to mitigate iron deficiency stress. Additionally, the absorption and accumulation of other metal ions were enhanced, likely as a compensatory mechanism for iron scarcity. At the transcriptional level, iron deficiency induced the expression of genes involved in metal absorption and transport, as well as those related to photosynthesis, carbon metabolism, and ribosomal function, thereby supporting iron homeostasis and maintaining metabolic balance under stress conditions. Full article

Coffee Coffea arabica L. depends on abundantly distributed rainfall, and drought negatively impacts plant development, fruit production, bean quality, and, ultimately, beverage quality. Plant biotechnology by means of genetic manipulation and plant regeneration by the somatic embryogenic process is an alternative technology to overcome these problems. In the present work, we used the molecular approach of the Trehalase gene silencing to allow trehalose accumulation favoring plants surviving in extreme drought/salt environments. We used a cassette containing the antisense C. arabica L. Trehalase gene under the RD29 promoter from A. thaliana and the NOS terminator to genetically modify an embryogenic coffee C. arabica L. cv Typica line under osmotic stress supplemented with mannitol (0.3 M) and sorbitol (0.3 M). Osmotic stress-tolerant somatic embryos lines were recovered and regenerated into plants. Tolerant somatic embryo lines showed a higher rate of competence to induce secondary SE capacity and plants robustness. These lines showed a down-regulation of the Trehalase; accumulation of trehalose, sucrose, starch, and proline; higher photosynthetic rate; improved water-use efficiency; and appropriated vapor deficit pressure under soil conditions. A transcriptome analysis was performed from highly competent somatic embryogenic lines to understand the molecular mechanisms underlying osmotic-stress tolerance. From the up-regulated genes, a PPI network made by STRING v12.0 with high confidence (0.700) revealed the presence of the 10 modules: the cell cycle, chromatin remodeling, somatic embryogenesis, oxidative stress, generic transcription pathway, carbon metabolism, phenylpropanoid biosynthesis, trehalose biosynthesis, proline biosynthesis, and glycerolipid metabolism. Full article

The document is an updated review, starting from the Special Issue “Molecular Breeding for Abiotic Stress Tolerance in Crops” published in the Int. J. Mol. Sci. It reviews molecular breeding strategies to enhance abiotic stress tolerance in crops, addressing challenges like drought, salinity, temperature extremes, and waterlogging, which threaten global food security. Climate change intensifies these stresses, making it critical to develop resilient crop varieties. Plants adapt to stress through mechanisms such as hormonal regulation (e.g., ABA, ethylene), antioxidant defense (e.g., SOD, CAT), osmotic adjustment (e.g., proline accumulation), and gene expression regulation via transcription factors like MYB and WRKY. Advanced tools, such as CRISPR/Cas9 genome editing, enable precise modifications of stress-related genes, improving tolerance without compromising yield. Examples include rice (OsRR22, OsDST) and wheat (TaERF3, TaHKT1;5). Epigenetic regulation, including DNA methylation and histone modifications, also plays a role in stress adaptation. Specific studies focused on polyamine seed priming for improved germination and stress resistance, cadmium detoxification mechanisms, and genome-wide association studies (GWAS) to identify genetic markers for salt tolerance and yield. Research on salinity tolerance in wheat emphasizes sodium exclusion and tissue tolerance mechanisms. Future perspectives focus on genetic engineering, molecular markers, epigenetic studies, and functional validation to address environmental stress challenges, including the use of AI and machine learning to manage the large amount of data. The review underscores the importance of translating molecular findings into practical applications to ensure sustainable crop production under changing climates. Full article

Pseudomonas aeruginosa is an opportunistic pathogen capable of forming antibiotic-resistant biofilms, contributing to persistent infections and treatment failure. Environmental factors such as osmolarity and nutrient availability are known to influence biofilm formation and virulence. In this study, we investigated the effects of NaCl depletion and glutamine supplementation on biofilm production in three P. aeruginosa strains: the laboratory strain ATCC 27853 and two clinical isolates with distinct antibiotic resistance profiles and phenazine production patterns (P. aeruginosa Pr, pyorubrin-producing, and P. aeruginosa Pc, pyocyanin-producing). Bacteria were cultured in standard Luria–Bertani (LB) medium, LB without NaCl, and LB in which yeast extract was replaced by glutamine. For each strain and condition, we assessed growth kinetics, phenazine production, and biofilm formation. Biofilm development was quantified via XTT assays and compared to secondary metabolite profiles. NaCl removal did not substantially affect growth, whereas glutamine supplementation reduced growth, especially in the laboratory strain. Both conditions modulated secondary metabolite production and biofilm formation in a strain-specific manner. In P. aeruginosa ATCC 27853, NaCl depletion significantly increased pyoverdine, pyocyanin, and QS gene expression, while biofilm formation showed significant differences only at 72 h; in contrast, glutamine supplementation affected only pyoverdine. A similar trend was observed in the clinical strain P. aeruginosa Pc, although NaCl depletion did not significantly impact pyoverdine production but already enhanced biofilm formation at 48 h. In P. aeruginosa Pr, only glutamine appeared to alter the considered parameters, increasing pyoverdine production while reducing pyocyanin and biofilm levels, although the absence of NaCl also negatively impacted biofilm formation. These findings highlight the impact of osmotic and nutritional signals on P. aeruginosa virulence traits. Full article

Microbial inoculants, as a new type of product that combines economic efficiency with ecological sustainability, play an important role in promoting plant growth and development, increasing crop yields, and enhancing plant resistance to abiotic stress. This study used the wine grape cultivar (Vitis vinifera ‘Pinot Noir’) as experimental material to systematically investigate the effects of microbial inoculants on the soil–leaf–fruit system during the late growth stage of grapes under salt stress conditions (200 mM NaCl). This study analyzed the regulatory effects of microbial inoculants on soil physicochemical properties, leaf physiological and biochemical characteristics, as well as fruit yield and quality. The results showed that salt stress significantly inhibited the growth of Pinot Noir grapes. However, the application of microbial inoculants effectively alleviated the negative effects of salt stress. By enhancing the plant’s antioxidant defense capacity and regulating physiological metabolic pathways such as osmotic balance, the inoculants significantly mitigated the inhibitory effect of salt stress on fruit development. Notably, the S+JH treatment group demonstrated particularly outstanding results, with hundred-berry weight, single-bunch weight, and yield per plant increasing significantly by 15.96%, 12.47%, and 28.93%, respectively, compared to the salt stress group (S). Additionally, this treatment also stabilized free amino acid content and suppressed excessive organic acid synthesis. This study provides new technical insights into the application of microbial inoculants for saline-alkali land improvement and stress-resistant cultivation of horticultural crops such as grapes, holding significant practical value for promoting the sustainable development of the grape industry in saline-alkali regions. Full article

As the ancestor and close relative of soybeans, wild soybeans exhibit strong salt tolerance and are ideal materials for discovering salt-tolerant genes. Expansins are a type of cell wall-loosening protein that plays an active role in regulating plant salt tolerance. We previously obtained the wild soybean expansin gene GsEXPB1, which is specifically transcribed in roots and actively responds to salt stress. Overexpression of this gene significantly promotes the growth of soybean hairy roots under salt stress. To further elucidate the function of the gene in regulating plant tolerance to salt stress, this study obtained soybean hairy roots that overexpress the GsEXPB1 gene and silence its homologous gene GmEXPB4 through RNAi. Under salt stress, the overexpression of the GsEXPB1 gene significantly promoted the growth of soybean hairy roots, while the hairy roots that were silenced for the GmEXPB4 gene exhibited an opposite phenotype. Physiological assay results indicate that GsEXPB1 enhances the tolerance of soybean hairy roots to salt stress by regulating the antioxidant system and Na⁺/K⁺ content. In soybean lines overexpressing GsEXPB1, the germination rate of seeds and root growth indicators under salt stress were significantly improved compared to those of wild-type plants. Meanwhile, GsEXPB1 enhances the tolerance of transgenic lines to salt stress by actively regulating the antioxidant system, osmotic adjustment system, chlorophyll content, cell wall components, and Na⁺/K⁺ levels, significantly promoting growth and increasing the number of flowers and grain weight. This study reveals the physiological mechanism by which GsEXPB1 enhances soybean salt tolerance, providing a theoretical basis and relevant references for the application of this gene in the breeding of new soybean salt-tolerant varieties. Full article

Drought stress is a major environmental factor that adversely affects plant growth and development. Spermidine (SPD), a polyamine, plays a critical role in plant defense mechanisms against drought stress. PEG was used to simulate osmotic stress, which mimics drought conditions under controlled environments. This study investigated the effects of exogenous spermidine (SPD) on the physiological and biochemical responses of mango plants under drought stress and explored its potential mitigation mechanisms. Two-year-old ‘Renong 1’ mango seedlings were subjected to drought stress induced by polyethylene glycol (PEG 6000) at concentrations of 5%, 15%, and 25%, simulating mild, moderate, and severe drought conditions, respectively. Plants were subsequently treated with 1 mmol/L spermidine. After PEG 6000 treatment and spermidine application for 3 days, the leaf morphology, relative chlorophyll content, malondialdehyde (MDA) levels, antioxidant enzyme activities (superoxide dismutase [SOD], peroxidase [POD], catalase [CAT]), and osmotic regulators (proline, soluble sugars, and soluble proteins) were analyzed. The results demonstrated that drought stress caused leaf chlorosis, desiccation, reduced relative chlorophyll content, elevated MDA levels (indicating lipid peroxidation), enhanced antioxidant enzyme activities, increased proline and soluble sugar accumulation for osmotic regulation, and decreased soluble protein content. Exogenous spermidine treatment significantly alleviated drought-induced damage by reducing leaf chlorosis, delaying relative chlorophyll degradation (by 20.0–25.7% under moderate drought and 14.1–19.1% under severe drought), and decreasing MDA levels (by 4.8–9.5% under moderate drought and 0.8–23.7% under severe drought). Furthermore, spermidine enhanced antioxidant enzyme activities (e.g., SOD activity increased by 24.9–37.4% and POD by 74.0–104.0% under moderate drought), regulated osmotic substance accumulation (e.g., proline decreased by 21%, 26%, and 24% under mild, moderate, and severe drought, respectively), and mitigated the reduction in soluble protein content (by 6.6% under moderate drought and 10.3% under severe drought). In conclusion, exogenous spermidine mitigates drought-induced damage in mango by preserving photosynthetic capacity, enhancing the antioxidant defense system, and modulating osmotic balance. These results showed that SPD could significantly improve plant vigor or survival rate under stress. It provides a theoretical basis for water-saving cultivation of mango, improving the stress resistance of mango varieties and the application of spermidine in tropical fruit production. Full article

Background: Liver function is a critical factor, both in the selection of treatment and in the prediction of prognosis in patients with hepatocellular carcinoma (HCC). The ALBI grade, introduced as a more objective method of assessing liver function, utilizes serum albumin (Alb) and total bilirubin (Bil) levels. Although albumin is widely recognized for its role in maintaining colloid osmotic pressure and regulating plasma volume, recent studies have implicated it in tumor progression, invasion, and metastasis. The purpose of this study is to determine the impact of serum albumin levels on overall survival (OS) and tumor invasion/metastasis in HCC patients with the same liver function (ALBI grade) at the time of diagnosis. Methods: In this study, 285 patients diagnosed with primary HCC at our institution from 2015 to 2019 were classified by ALBI grade and analyzed. Among them, 78 patients with ALBI grade 2 status were selected to evaluate the impact of albumin level. To further isolate the effect of albumin rather than bilirubin, patients in the ALBI grade 2 cohort were divided into two groups based on mean values of Alb (3.5 g/dL) and Bil (1.0 mg/dL). Alb normal group (Group A): Alb ≥ 3.5 g/dL, Bil ≥ 1.0 mg/dL (n = 42). Bil normal group (Group T): Alb < 3.5 g/dL, Bil < 1.0 mg/dL (n = 36). Liver function was almost the same in these two groups based on the ALBI grade. OS, progression-free survival (PFS), types of recurrence, and pathological findings were compared between the two groups. OS was analyzed by the log-rank test, and comparisons between the two groups were performed by the t-test and chi-square test, with p < 0.05 indicating statistical significance. Results: OS was significantly worse in Group T than in Group A before and after propensity score matching based on age, performance status, and HCC stage (p < 0.001 and p = 0.011). Among the 44 patients who received curative treatment (surgery or radiofrequency ablation), OS was also significantly worse in Group T (p < 0.001). An analysis of the recurrence patterns of 44 curatively treated patients revealed that Group T had significantly shorter PFS (p < 0.001), and all recurrence patterns were multiple (p = 0.002). Pathological analysis in 28 surgical patients showed that serosal invasion was present in significantly more patients in Group T (p = 0.003). Conclusions: Low serum albumin levels in patients with HCC indicate both liver dysfunction and increased tumor invasion and metastasis. Nutritional support and albumin supplementation may help reduce intrahepatic metastases and improve prognosis. Further studies are needed to explore the underlying mechanisms and therapeutic potential. Full article

Lacticaseibacillus rhamnosus (Lbs. rhamnosus) is renowned for its tolerance to gastric acid and adaptability to bile and alkaline conditions, and is crucial for intestinal health and immune regulation. In this study, integrated transcriptomic and proteomic analyses were employed to elucidate the response mechanisms of Lbs. rhamnosus under osmotic stress, induced by exposure to 0.6 M sodium lactate, which elevates environmental osmotic pressure. It was shown that 792 differentially expressed genes and 138 differentially expressed proteins were detected in Lbs. rhamnosus ATCC 53103 treated with osmotic stress. The differential regulation of these genes/proteins mainly includes the inhibition of fatty acid metabolism with membrane structural remodeling (downregulation of the acetyl coenzyme A carboxylase family and fatty acid binding protein family expression), dynamic homeostasis of amino acid metabolism (restriction of the synthesis of histidine, cysteine, leucine, etc., and enhancement of the catabolism of lysine, tryptophan, etc.), and survival-oriented reconfiguration of carbohydrate metabolism (gene expression related to the glycolytic pathway increases, while gene expression related to the pentose phosphate pathway decreases). These synergistic alterations in metabolic regulation may facilitate the adaptive response of Lbs. rhamnosus ATCC 53103 to osmotic stress. Overall, our findings deepen the current understanding of the stress response mechanisms in lactic acid bacteria and offer novel insights into the survival strategies employed by Lbs. rhamnosus ATCC 53103 under hyperosmotic conditions. Full article

Background: The escalating global salinization poses a significant threat to agricultural productivity, necessitating a thorough understanding of plant responses to high salinity. Pea sprouts (Pisum sativum), a nutrient-rich crop increasingly cultivated in salinized regions, serve as an ideal model for such investigations due to their rapid growth cycle and documented sensitivity to ionic stress. Methods: In order to understand the response of pea sprouts in physiological regulation, redox-metabolic adjustments, and transcriptome reprogramming under salt stress, we investigated the effects of high salt concentrations on the ascorbic acid–glutathione cycle, endogenous hormone levels, metabolite profiles, and gene expression patterns in it. Results: Our findings reveal early-phase antioxidant/hormonal adjustments, mid-phase metabolic shifts, and late-phase transcriptomic reprogramming of pea sprouts under salt conditions. In addition, a biphasic response in the ascorbic acid cycle was found, with initial increases in enzyme activities followed by a decline, suggesting a temporary enhancement of antioxidant defenses. Hormonal profiling indicated a significant increase in abscisic acid (ABA) and jasmonic acid (JA), paralleled by a decrease in indole acetic acid (IAA) and dihydrozeatin (DZ), underscoring the role of hormonal regulation in stress adaptation. Metabolomic analysis uncovered salt-induced perturbations in sugars, amino acids, and organic acids, reflecting the metabolic reconfiguration necessary for osmotic adjustment and energy reallocation. Transcriptomic analysis identified 6219 differentially expressed genes (DEGs), with a focus on photosynthesis, hormone signaling, and stress-responsive pathways, providing insights into the molecular underpinnings of salt tolerance. Conclusions: This comprehensive study offers novel insights into the complex mechanisms employed by pea sprouts to combat salinity stress, contributing to the understanding of plant salt tolerance and potentially guiding the development of salt-resistant crop varieties. Full article