Search Results (3,873)

This study evaluated the antibacterial efficacy of 700 feline-derived lactic acid bacteria (LAB) strains against enteropathogenic Escherichia coli (EPEC), a common cause of diarrhea in cats. Following comprehensive screening, strains ZY25 and ZY35 were identified as the most effective, with inhibition zones of ≥22 mm. These strains demonstrated strong tolerance against stress conditions, such as low pH, bile salts, and gastrointestinal fluids, alongside high hydrophobicity and auto-aggregation abilities. Safety evaluations confirmed the absence of hemolytic activity, virulence factors, and antibiotic resistance genes. The antibacterial activity of these strains is attributed to the production of organic acids, particularly lactic acid and acetic acid. These findings suggest that strains ZY25 and ZY35 have potential as natural and effective probiotic treatments for managing EPEC-induced diarrhea in cats, thus offering an alternative to conventional antibiotics. Full article

Soil salinization is currently one of the main abiotic stresses that restrict plant growth. Plant endophytic bacteria can alleviate abiotic stress. The aim of the current study was to isolate, characterize, and assess the plant growth-promoting and saline and alkaline stress-alleviating traits of Peribacillus simplex M1 (P. simplex M1) isolates from maize. One endophytic bacterial isolate, named P. simplex M1, was selected from the roots of maize grown in saline–alkali soil. The P. simplex M1 genome sequence analysis of the bacteria with a length of 5.8 Mbp includes about 700 genes that promote growth and 16 antioxidant activity genes that alleviate saline and alkaline stress. P. simplex M1 can grow below 400 mM NaHCO₃ on the LB culture medium; The isolate displayed multiple plant growth-stimulating features, such as nitrogen fixation, produced indole-3-acetic acid (IAA), and siderophore production. This isolate had a positive effect on the resistance to salt of maize in addition to the growth. P. simplex M1 significantly promoted seed germination by enhancing seed vigor in maize whether under normal growth or NaHCO₃ stress conditions. The seeds with NaHCO₃ treatment exhibited higher reactive oxygen species (ROS) levels than the maize in P. simplex M1 inoculant on maize. P. simplex M1 can colonize the roots of maize. The P. simplex M1 inoculant plant increased chlorophyll in leaves, stimulated root and leaf growth, increased the number of lateral roots and root dry weight, increased the length and width of the blades, and dry weight of the blades. The application of inoculants can significantly reduce the content of malondialdehyde (MDA) and increase the activity of plant antioxidant enzymes (Catalase (CAT), Superoxide Dismutase (SOD), and Peroxidase (POD)), which may thereby improve maize resistance to saline and alkaline stress. Conclusion: P. simplex M1 isolate belongs to plant growth-promoting bacteria by having high nitrogen concentration, indoleacetic acid (IAA), and siderophore, and reducing the content of ROS through the antioxidant system to alleviate salt alkali stress. This study presents the potential application of P. simplex M1 as a biological inoculant to promote plant growth and mitigate the saline and alkaline effects of maize and other crops. Full article

The flavonoids play important roles in plant salt tolerance. Blueberries (Vaccinium spp.) are extremely sensitive to soil salt increases. Therefore, improving the salt resistance of blueberries by increasing the flavonoid content is crucial for the development of the blueberry industry. To explore the underlying molecular mechanism, we performed an integrated analysis of the metabolome and transcriptome of blueberry leaves under salt stress. We identified 525 differentially accumulated metabolites (DAMs) under salt stress vs. control treatment, primarily including members of the flavonoid class. We also identified 20,920 differentially expressed genes (DEGs) based on transcriptome data; of these, 568 differentially expressed transcription factors (TFs) were annotated, and bHLH123, OsHSP20, and HSP20 TFs might be responsible for blueberry leaf salt tolerance. DEGs involved in the flavonoid biosynthesis pathway were significantly enriched at almost all stages of salt stress. Salt treatment upregulated the expression of most flavonoid biosynthetic pathway genes and promoted the accumulation of flavonols, flavonol glycosides, flavans, proanthocyanidins, and anthocyanins. Correlation analysis suggested that 4-coumarate CoA ligases (4CL5 and 4CL1) play important roles in the accumulation of flavonols (quercetin and pinoquercetin) and flavan-3-ol (epicatechin and prodelphinidin C2) under salt stress, respectively. The flavonoid 3′5′-hydroxylases (F3′5′H) regulate anthocyanin (cyanidin 3-O-beta-D-sambubioside and delphinidin-3-O-glucoside chloride) biosynthesis, and leucoanthocyanidin reductases (LAR) are crucial for the biosynthesis of epicatechin and prodelphinidin C2 during salt stress. Taken together, it is one of the future breeding goals to cultivate salt-resistant blueberry varieties by increasing the expression of flavonoid biosynthetic genes, especially 4CL, F3′5′H, and LAR genes, to promote flavonoid content in blueberry leaves. Full article

The extreme weather and the deteriorating water environment have exacerbated the crisis of freshwater resource insufficiency. Many studies have shown that salty water could replace freshwater to partly meet the water demand of plants. To study the effects of early-stage drought hardening and late-stage salt stress on tomatoes (Solanum lycopersicum L.), we conducted a 2-year pot experiment. Based on the multi-objective demands of high yield, high quality, and water saving, yield indicators, quality indicators, and a water-saving indicator were selected as evaluation indicators. Three irrigation levels (W1: 85% field capacity (FC), W2: 70% FC, W3: 55% FC) and three salinity levels (S2: 2 g/L, S4: 4 g/L, S6: 6 g/L) were set as nine treatments. In addition, a control treatment (CK: W1, 0 g/L) was added. Each treatment was evaluated and scored by principal component analysis. The results for 2022 and 2023 found the highest scores for CK, W2S2, W3S2 and CK, W2S4, W2S2, respectively. Based on response surface methodology, we constructed composite models of multi-objective demands, whose results indicated that 66–72% FC and 2 g/L salinity were considered the appropriate water–salt combinations for practical production. This paper will be beneficial for maintaining high yield and high quality in tomato production using salty water irrigation. Full article

Soil salinization, especially in arid and semi-arid regions, is one of the major abiotic stresses that affect plant growth. To mediate and boost plant tolerance against this abiotic stress, arbuscular mycorrhizal fungi (AMF) symbiosis is commonly thought to be an effective tool. So, the main purpose of this study was to estimate the role of AMF (applied as a consortium of Claroideoglomus etunicatum, Funneliformis mosseae, Rhizophagus fasciculatum, and R. intraradices species) symbiosis in mitigating deleterious salt stress effects on the growth parameters (shoot length (SL), root length (RL), shoot dry weight (SDW), root dry weight (RDW), root surface area (RSA), total root length (TRL), root volume (RV), root diameter (RD), number of nodes and leaves) of Cenchrus ciliaris L. plants through improved accumulations of photosynthetic pigments (chlorophyll _a, chlorophyll _b, total chlorophyll), proline and phenolic compounds. The results of this experiment revealed that the roots of C. ciliaris plants were colonized by AMF under all the applied salinity levels (0, 75, 150, 225, and 300 mM NaCl). However, the rate of colonization was negatively affected by increasing salinity as depicted by the varied colonization structures (mycelium, vesicles, arbuscules and spores) which were highest under non-saline conditions. This association of AMF induced an increase in the growth parameters of the plant which were reduced by salinity stress. The improved shoot/root indices are likely due to enhanced photosynthetic activities as the AMF-treated plants showed increased accumulation of pigments (chlorophyll _a, chlorophyll _b and total chlorophyll), under saline as well as non-saline conditions, compared to non-AMF (N-AMF) plants. Furthermore, the AMF-treated plants also exhibited enhanced accumulation of proline and phenolic compounds. These accumulated metabolites act as protective measures under salinity stress, hence explaining the improved photosynthetic and growth parameters of the plants. These results suggest that AMF could be a good tool for the restoration of salt-affected habitats. However, more research is needed to check the true efficacy of different AMF inoculants under field conditions. Full article

Salt stress can adversely affect global agricultural productivity, necessitating innovative strategies to mitigate its adverse effects on plant growth and yield. This study investigated the effects of exogenous salicylic acid (SA), grafting (G), and their combined application (GSA) on various parameters in tomato plants subjected to salt stress. The analysis focused on growth characteristics, photosynthesis, osmotic stress substances, antioxidant enzyme activity, plant hormones, ion content, and transcriptome profiles. Salt stress severely inhibits the growth of tomato seedlings. However, SA, G, and GSA improved the plant height by 22.5%, 26.5%, and 40.2%; the stem diameter by 11.0%, 26.0%, and 23.7%; the shoot fresh weight by 76.3%, 113.2%, and 247.4%; the root fresh weight by 150.9%, 238.6%, and 286.0%; the shoot dry weight by 53.5%, 65.1%, and 162.8%; the root dry weight by 150.0%, 150.0%, and 166.7%, and photosynthesis by 4.0%, 16.3%, and 32.7%, with GSA presenting the most pronounced positive effect. Regarding the osmotic stress substances, the proline content increased significantly by more than 259.2% in all treatments, with the highest levels in GSA. Under salt stress, the tomato seedlings accumulated high Na⁺ levels; the SA, G, and GSA treatments enhanced the K⁺ and Ca²⁺ absorption while reducing the Na⁺ and Al³⁺ levels, thereby alleviating the ion toxicity. The transcriptome analysis indicated that SA, G, and GSA influenced tomato growth under salt stress by regulating specific signaling pathways, including the phytohormone and MAPK pathways, which were characterized by increased endogenous SA and decreased ABA content. The combined application of grafting and exogenous SA could be a promising strategy for enhancing plant tolerance to salt stress, offering potential solutions for sustainable agriculture in saline environments. Full article

Increasing soil and water salinity threatens global agriculture, particularly affecting rice. This study investigated the residual effects of microbial biochar and nitrogen fertilizer in mitigating salt stress in paddy soil and regulating the biochemical characteristics of rice plants. Two rice varieties, Shuang Liang You 138 (SLY138), a salt-tolerant, and Jing Liang You 534 (JLY534), a salt-sensitive, were grown under 0.4 ds/m EC (S0) and 6.84 ds/m EC (S1) in a glass house under controlled conditions. Three types of biochar—rice straw biochar (BC), fungal biochar (BF), and bacterial biochar (BB)—were applied alongside two nitrogen (N) fertilizer rates (60 kg ha⁻¹ and 120 kg ha⁻¹) in a previous study. The required salinity levels were maintained in respective pots through the application of saline irrigation water. Results showed that residual effects of microbial biochars (BF and BB) had higher salt mitigation efficiency than sole BC. The combination of BB and N fertilizer (BB + N120) significantly decreased soil pH by 23.45% and Na⁺ levels by 46.85%, creating a more conducive environment for rice growth by enhancing beneficial microbial abundance and decreasing pathogenic fungi in saline soil. Microbial biochars (BF and BB) positively improved soil properties (physicochemical) and biochemical and physiological properties of plants, ultimately rice growth. SLY138 significantly had a less severe response to salt stress compared to JLY534. The mitigation effects of BB + N120 kg ha⁻¹ were particularly favorable for SLY138. In summary, the combined residual effect of BF and BB with N120 kg ha⁻¹, especially bacterial biochar (BB), played a positive role in alleviating salt stress on rice growth, suggesting its potential utility for enhancing rice yield in paddy fields. Full article

In saline conditions, establishing healthy seedlings is crucial for the productivity of sunflowers (Helianthus annuus L.). Excessive potassium (K⁺) from irrigation water or overfertilization, similar to sodium (Na⁺), could adversely affect sunflower growth. However, the effects of salt stress caused by varying K/Na ratios on the establishment of sunflower seedlings have not been widely studied. We conducted a pot experiment in a greenhouse, altering the K/Na ratio of a soil solution to grow sunflower seedlings. We tested three saline solutions with K/Na ratios of 0:1 (P0S1), 1:1 (P1S1), and 1:0 (P1S0) at a constant concentration of 4 dS m⁻¹, along with a control (CK, no salt added), with five replicates. The solutions were applied to the pots via capillary rise through small holes at the bottom. The results indicate that different K/Na ratios significantly influenced ion-selective uptake and transport in crop organs. With an increasing K/Na ratio, the K⁺ concentration in the roots, stems, and leaves increased, while the Na⁺ concentration decreased in the roots and stems, with no significant differences in the leaves. Furthermore, an excessive K/Na ratio (P1S0) suppressed the absorption and transportation of Mg²⁺, significantly reducing the Mg²⁺ concentration in the stems and leaves. A lower leaf Mg²⁺ concentration reduced chlorophyll concentration, impairing photosynthetic performance. The lowest plant height, leaf area, dry matter, and shoot/root ratio were observed in P1S0, with reductions of 27%, 48%, 48%, and 13% compared to CK, respectively. Compared with CK, light use efficiency and CO₂ use efficiency in P1S0 were significantly reduced by 13% and 10%, respectively, while water use efficiency was significantly increased by 9%. Additionally, improved crop morphological and photosynthetic performance was observed in P1S1 and P0S1 compared with P1S0. These findings underscore the critical role of optimizing ion composition in soil solutions, especially during the sensitive seedling stage, to enhance photosynthesis and ultimately to improve the plant’s establishment. We recommend that agricultural practices in saline regions incorporate tailored irrigation and fertilization strategies that prioritize optimal K/Na ratios to maximize crop performance and sustainability. Full article

The increase in the frequency and magnitude of environmental stresses poses a significant risk to the stability of food supplies. In coastal areas of the Mediterranean, brackish water has long been considered a limitation on horticultural production. In this scenario, the use of biochar in agriculture could be considered a valuable tool to cope with the deleterious effects of salt stress. This work aimed to investigate, in a protected environment, the effects of different concentrations of biochar (0, 1, and 2% v/v) obtained from poplar (Populus L.) biomass on the yield and quality of dwarf San Marzano ecotype tomatoes irrigated with saline water at different concentrations of NaCl (0, 40 and 80 mM). The increase in salt concentration from 0 to 80 mM NaCl reduced the total yield (−63%) and the number of fruits (−25%), but improved the main quality parameters such as dry matter (+75%), total soluble solids (+56%), and polyphenol content (+43%). Compared to control conditions, biochar supplementation improved the total yield (+23%) and number of fruits (+26%) without altering the functional and organoleptic characteristics of the fruits. The promising results underscore the potential of biochar as a sustainable solution to amend soils in order to improve tomato production under unfavorable conditions such as high salinity. However, there is a need to clarify which adaptation mechanisms triggered by biochar amending improve production responses even and especially under suboptimal growing conditions. Full article

The ATP-binding cassette (ABC) proteins are a diverse family of transmembrane transporter proteins widely identified in various organisms. The ABCG transporters belong to the G subfamily of the ABC transporter family. Rarely research on ABCG transporters involved in salt tolerance of rice was found. In this study, the evolutionary relationships, conserved motifs, intra- and inter-species homologous genes, and cis-acting elements of ABCG subfamily members were analyzed, and the expression changes of these genes under salt stress at 0 h, 3 h, and 24 h were detected. Based on these results, the candidate gene OsABCG7, which is induced by salt stress, was selected for further studies. Yeast experiments confirmed that the OsABCG7 gene might be involved in the regulation of salt tolerance. The abcg7 mutant showed a higher degree of leaf wilting and a lower survival rate, exhibiting a salt-sensitive phenotype. Systematic analysis of this family in rice helps design effective functional analysis strategies and provides data support for understanding the role of ABCG transporters under salt stress. Full article

Brassinosteroid (BR) signaling is regulated by BRI1-EMS SUPPRESSOR 1 (BES1) transcription factors, which are crucial for plant growth, development, and stress responses. Despite their importance, BES1 gene studies in Medicago sativa L. are limited, hindering our understanding of the BR signaling in this species. This study identified four BES1 genes in M. sativa; characterized their properties, conserved motifs, cis-regulatory elements, and chromosomal location; and explored their functions in development and stress responses. A phylogenetic analysis grouped these genes into two subfamilies. Transcript profiling showed widespread and tissue-specific expression patterns. A qRT-PCR analysis unveiled that most MsBESI genes were upregulated under salt and drought treatments, except MsG0280009980, which was suppressed. This research lays the groundwork for enhancing M. sativa stress resistance and understanding the BES1 gene family’s function. Full article

Salt stress could be a significant factor limiting the growth and development of vegetables. In this study, Fulvic Acid (FA) (0.05%, 0.1%, 0.15%, 0.2%, and 0.25%) was applied under nitrate stress (150 mM), with normal Hoagland nutrient solution as a control to investigate the influence of foliar spray FA on spinach growth, photosynthesis, and oxidative stress under nitrate stress. The results showed that nitrate stress significantly inhibited spinach growth, while ROS (reactive oxygen species) accumulation caused photosystem damage, which reduced photosynthetic capacity. Different concentrations of FA alleviated the damage caused by nitrate stress in spinach to varying degrees in a concentration-dependent manner. The F3 treatment (0.15% FA + 150 mM NO₃⁻) exhibited the most significant mitigating effect. FA application promoted the accumulation of biomass in spinach under nitrate stress and increased chlorophyll content, the net photosynthetic rate, the maximum photochemical quantum yield of PSII (Photosystem II) (Fv/Fm), the quantum efficiency of PSII photochemistry [Y(II)], the electron transport rate, and the overall functional activity index of the electron transport chain between the PSII and PSI systems (PItotal); moreover, FA decreased PSII excitation pressure (1 − qP), quantum yields of regulated energy dissipation of PSII [Y(NPQ)], and the relative variable initial slope of fluorescence. FA application increased superoxide dismutase, peroxidase, and catalase activities and decreased malondialdehyde, H₂O₂, and O₂⁻ levels in spinach under nitrate stress. FA can enhance plant resistance to nitrate by accelerating the utilization of light energy in spinach to mitigate excess light energy and ROS-induced photosystem damage and increase photosynthetic efficiency. Full article

Soybean is an important grain, oil and feed crop, which plays an important role in ensuring national food security. However, soil salinization hinders and destroys the normal physiological metabolism of soybean, resulting in the abnormal growth or death of soybean. The XTH gene can modify the plant cell wall and participate in the response and adaptation of plants to negative stress. To elucidate the role of the overexpressed GmXTH1 gene under NaCl-induced stress in soybean, we determined the germination rate, the germination potential, the germination index, seedling SOD activity, POD activity, the MDA content and the MDA content during the germination stage of the overexpressed lines of the GmXTH1 gene, the OEAs (OEA1, OEA2 and OEA3), the interference expression line IEA2, the control mutant M18, the CAT content and the chlorophyll content. The relative expression of the GmXTH1 gene in the material OEA1 and the contents of Na⁺ and K⁺ in the roots after stress were also determined. The results showed that OEAs exhibited enhanced germination indices, including the germination rate and germination potential, and were less sensitive to stress compared with the mutant M18. In contrast, the inhibitory effect of NaCl was more pronounced in the line with a disturbed expression of GmXTH1 (IEA2). The OEAs exhibited more enzyme activities and a lower MDA content, indicating reduced oxidative stress, and maintained higher chlorophyll levels, suggesting improved photosynthetic capacity. Relative expression analysis showed that the GmXTH1 gene was rapidly up-regulated in response to NaCl, peaking at 4 h after treatment, and subsequently declining. This temporal expression pattern correlated with the enhanced salt tolerance observed in OEA1. Notably, OEA1 accumulated more Na⁺ and maintained higher K⁺ levels, indicating effective ionic homeostasis under stress. Collectively, these results suggest that the overexpression of the GmXTH1 gene may positively regulate plant responses to salt stress by modulating the antioxidant defense and ion transport mechanisms. Full article

The unscientific application of nitrogen (N) fertilizer not only increases the economic input of pear growers but also leads to environmental pollution. Improving plant N use efficiency (NUE) is the most effective economical method to solve the above problems. The absorption and utilization of N by plants is a complicated process. Glutamine synthetase (GS) and glutamate synthase (GOGAT) are crucial for synthesizing glutamate from ammonium in plants. However, their gene family in pears has not been documented. This study identified 29 genes belonging to the GS and GOGAT family in the genomes of Pyrus betulaefolia (P.be, 10 genes), Pyrus pyrifolia (P.py, 9 genes), and Pyrus bretschneideri (P.br, 10 genes). These genes were classified into two GS subgroups (GS1 and GS2) and two GOGAT subgroups (Fd–GOGAT and NADH–GOGAT). The similar exon–intron structures and conserved motifs within each cluster suggest the evolutionary conservation of these genes. Meanwhile, segmental duplication has driven the expansion and evolution of the GS and GOGAT gene families in pear. The tissue–specific expression dynamics of PbeGS and PbeGOGAT genes suggest significant roles in pear growth and development. Cis–acting elements of the GS and GOGAT gene promoters are crucial for plant development, hormonal responses, and stress reactions. Furthermore, qRT–PCR analysis indicated that PbeGSs and PbeGOGATs showed differential expression under exogenous hormones (GA₃, IAA, SA, ABA) and abiotic stress (NO₃⁻ and salt stress). In which, the expression of PbeGS2.2 was up–regulated under hormone treatment and down–regulated under salt stress. Furthermore, physiological experiments demonstrated that GA₃ and IAA promoted GS, Fd–GOGAT, and NADH–GOGAT enzyme activities, as well as the N content. Correlation analysis revealed a significant positive relationship between PbeGS1.1, PbeGS2.2, PbeNADH–GOGATs, and the N content. Therefore, PbeGS1.1, PbeGS2.2, and PbeNADH–GOGATs could be key candidate genes for improving NUE under plant hormone and abiotic stress response. To the best of our knowledge, our study provides valuable biological information about the GS and GOGAT family in the pear for the first time and establishes a foundation for molecular breeding aimed at developing high NUE pear rootstocks. Full article

JASMONATE ZIM domain (JAZ) proteins, inhibitors of the jasmonic acid (JA) signaling pathway, are identified in different plants, such as rice and Arabidopsis. These proteins are crucial for growth, development, and abiotic stress responses. However, limited information is available regarding the JAZ family in alfalfa. This study identified 11 JAZ genes (MsJAZs) in the “Zhongmu No.1” reference genome of alfalfa. The physical and chemical properties, chromosome localization, phylogenetic relationships, gene structure, cis-acting elements, and collinearity of the 11 MsJAZ genes were subsequently analyzed. Tissue-specific analysis revealed distinct functions of different MsJAZ genes in growth and development. The expression patterns of MsJAZ genes under salt stress conditions were validated using qRT-PCR. All MsJAZ genes responded to salt stress, with varying levels of upregulation over time, highlighting their role in stress responses. Furthermore, heterogeneous expression of MsJAZ1 in Arabidopsis resulted in significantly lower seed germination and survival rates in OE-2 and OE-4 compared to the WT under 150 mM NaCl treatment. This study establishes a foundation for further exploration of the function of the JAZ family and provides significant insights into the genetic improvement of alfalfa. Full article