Search Results (141)

Soil salinization limits the growth of agricultural crops in the world, requiring the use of methods to increase the tolerance of agricultural crops to salinity–alkali stress. Arbuscular mycorrhizal fungi (AMF) enhance plant stress adaptation through symbiosis and offer a promising strategy for remediation. However, in non-model crops such as oat (Avena sativa L.), research has mainly focused on physiological assessments, while the key genes and metabolic pathways involved in AMF-mediated growth and saline–alkali tolerance remain unclear. In this study, we employed integrated multi-omics and physiological analyses to explore the regulatory mechanisms of AMF in oats under normal and saline–alkali stress. The results indicated that AMF symbiosis significantly promoted oat growth and physiological performance under both normal and saline–alkali stress conditions. Compared to the non-inoculated group under normal conditions, AMF increased plant height and biomass by 8.5% and 15.3%, respectively. Under saline–alkali stress, AMF enhanced SPAD value and relative water content by 16.7% and 7.3%, reduced MDA content by 35.8%, increased soluble protein by 21.8%, and decreased proline by 13.3%. In addition, antioxidant enzyme activities (SOD, POD, and CAT) were elevated by 18.4%, 18.2%, and 14.8%, respectively. Transcriptomic analysis revealed that AMF colonization under saline–alkali stress induced about twice as many differentially expressed genes (DEGs) as under non-saline–alkali stressed conditions. These DEGs were primarily associated with Environmental Information Processing, Genetic Information Processing, and Metabolic Processes. According to metabolomic analysis, a total of 573 metabolites were identified across treatments, mainly comprising lipids (29.3%), organic compounds (36.8%), and secondary metabolites (21.5%). Integrated multi-omics analysis indicated that AMF optimized energy utilization and antioxidant defense by enhancing phenylpropanoid biosynthesis and amino acid metabolism pathways. This study provides new insights into how AMF may enhance oat growth and tolerance to saline–alkali stress. 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

Soil salinization, affecting approximately 954 million hectares globally, severely impairs plant growth and agricultural productivity. Apocynum venetum L., a perennial herbaceous plant with ecological and economic value, demonstrates remarkable tolerance to saline and alkali soils. This study investigated the effects of saline (NaCl) and alkali (Na₂CO₃ and NaHCO₃) stress on the growth, anatomical adaptations, and metabolite accumulation of A. venetum (Apocynum venetum L.). Results showed that alkali stress (100 mM Na₂CO₃ and 50 mM NaHCO₃) inhibited growth more than saline stress (NaCl 240 mM), reducing plant height by 29.36%. Anatomical adaptations included a 40.32% increase in the root cortex-to-diameter ratio (100 mM Na₂CO₃ and 50 mM NaHCO₃), a 101.52% enlargement of xylem vessel diameter (NaCl 240 mM), and a 68.69% thickening of phloem fiber walls in the stem (NaCl 240 mM), enhancing water absorption, salt exclusion, and structural support. Additionally, leaf palisade tissue densification (44.68% increase at NaCl 160 mM), along with epidermal and wax layer adjustments, balanced photosynthesis and water efficiency. Metabolic responses varied with stress conditions. Root soluble sugar content increased 49.28% at NaCl 160 mM. Flavonoid accumulation in roots increased 53.58% at Na₂CO₃ 100 mM and NaHCO₃ 50 mM, enhancing antioxidant defense. However, chlorophyll content and photosynthetic efficiency declined with increasing stress intensity. This study emphasizes the coordinated adaptations of A. venetum, providing valuable insights for the development of salt-tolerant crops. Full article

In order to mitigate the reduction in soybean yield caused by soil salinization, a soybean gene, GmSNF4, which promotes plant tolerance to salt–alkali stress, was identified in this study. The STRING database was used to predict the interaction between GmSNF4 and GmPKS4. The GmPKS4 gene was experimentally shown to be involved in salt–alkali stress tolerance. Firstly, the yeast two-hybrid technique and bimolecular fluorescence complementation (BiFC) technique were used to confirm the interaction between GmSNF4 and GmPKS4: the AMPK-CBM-CBS1 conserved domain was thereby determined to be the region of the GmSNF4 protein involved in the interaction. Secondly, the GmSNF4 gene was induced by salt–alkali stress according to qRT-PCR analysis, and the GmSNF4 protein was localized in the nucleus and cytoplasm. Finally, analysis of GmSNF4’s role in resistance to salt–alkali stress in transgenic soybean plants showed that transgenic lines had better phenotypic, physiological, and stress-related gene expression than non-transgenic soybeans. Thus, GmSNF4 may play a significant role in plant salt–alkali stress tolerance. Full article

Gamma-aminobutyric acid (GABA), a ubiquitous non-protein amino acid, plays a vital role in the response of plants to biotic and abiotic stresses. This review summarizes the underlying mechanisms through which GABA contributes to plant stress resistance, including its biosynthetic and metabolic pathways, as well as its regulatory roles in enhancing stress tolerance and improving fruit quality. In plants, GABA is primarily synthesized from glutamate by the enzyme glutamate decarboxylase (GAD) and further metabolized by GABA transaminase (GABA-T) and succinic semialdehyde dehydrogenase (SSADH). The accumulation of GABA regulates various physiological and biochemical processes, including the control of stomatal closure, enhancement of antioxidant capacity, maintenance of ionic homeostasis, and stabilization of cellular pH. Moreover, GABA interacts with phytohormones to regulate plant growth, development, and stress tolerance. Notably, increasing GAD expression through genetic engineering has been shown to enhance tolerance to stresses, such as drought, saline-alkali, cold, and heat, in various plants, including tomato, rice, and creeping bentgrass. Additionally, GABA has effectively improved the storage quality of various fruits, including citrus fruits, apples, and strawberries. In conclusion, GABA holds significant research potential and promising applications in agricultural production and plant science. Full article

Soil salinization has become a major obstacle to global agricultural sustainability. While microbial inoculants show promise for remediation, the functional coordination between Trichoderma and PGPR in saline alkali rhizospheres requires systematic investigation. Pot studies demonstrated that while individual inoculations of Trichoderma longibrachiatum (M) or Bacillus aryabhattai (A2) moderately improved rice growth and soil properties, their co-inoculation (A2 + M) synergistically enhanced stress tolerance and nutrient availability—increasing available nitrogen (AN +28.02%), phosphorus (AP +11.55%), and potassium (AK +8.26%) more than either strain alone, while more effectively mitigating salinity (EC −5.54%) and alkalinity (pH −0.13 units). High-throughput sequencing further revealed that the A2 + M treatment reshaped the rhizosphere microbiome, uniquely enriching beneficial taxa (e.g., Actinomycetota [+9.68%], Ascomycota [+50.58%], Chytridiomycota [+152.43%]), and plant-growth-promoting genera (e.g., Sphingomonas, Trichoderma), while drastically reducing saline-alkali-adapted Basidiomycota (−87.96%). Further analysis identified soil organic matter (SOM), AN, and AP as key drivers for the enrichment of Chytridiomycota and Actinomycetota, whereas pH and EC showed positive correlations with Mortierellomycota, Aphelidiomycota, unclassified_k__Fungi, and Basidiomycota. Collectively, the co-inoculation of Trichoderma and PGPR strains enhanced soil microbiome structure and mitigated saline alkali stress in rice seedlings. These findings demonstrate the potential of microbial consortia as an effective bio-strategy for saline alkali soil amelioration. Full article

Due to prolonged irrigation from the Yellow River, a large area of farmland in the Hetao Oasis has undergone different degrees of salinization and alkalization, leading to reduced crop yields and incapable soil for plant growth. To enhance the productivity of the farmland with saline-alkali soils, it is important to select salt-tolerant economic plant species that are capable of growing under the local climate and soil conditions in the Hetao Oasis. We conducted the experiment by planting Ziziphus jujuba var. spinose, Elaeagnus angustifolia, Hippophae rhamnoides and Lycium chinense in the Bayan Taohai Farm of the Hetao Oasis. Changes of plant growth (the survival rate, plant height, canopy, basal diameter and new branch length) and soil physicochemical properties (soil organic carbon, total carbon, total nitrogen, pH, electrical conductivity and particle size distribution) were continuously monitored during two growing seasons. Results indicated that, by the end of the first growing season, the survival rate of the Z. jujuba was less than 10%, making it unsuitable for plantation in the saline-alkali soils of the Hetao Oasis. In terms of plant growth, the E. angustifolia exhibited the highest survival rate (94.71%) and the fastest growth rate, indicating that E. angustifolia is adapted in the saline-alkali soils of the Hetao Oasis. The survival rates for L. chinense and H. rhamnoides were 86.46% and 65.64%, respectively, indicating that these species could grow in the saline-alkali soils, but at a slower rate. From the perspective of soil improvement, E. angustifolia, H. rhamnoides and L. chinense could reduce the soil pH, and E. angustifolia could significantly increase soil nutrients. In conclusion, it is not recommended to plant Z. jujuba, while the E. angustifolia is recommended as a proper economic species to be widely planted in the saline-alkali soils of the Hetao Oasis. H. rhamnoides could be selectively planted in areas with better soil conditions, and the L. chinense could be planted following soil improvement measurements. The research enhanced the effective utilization of the saline-alkali farmland and provided proper economic plant species for sustainable agriculture management in the Hetao Oasis of Inner Mongolia. Full article

Saline–alkali land is a critical factor limiting agricultural production and ecological restoration. Utilizing salt-tolerant plants for bioremediation represents an environmentally friendly and sustainable approach to soil management. This study employed the highly salt-tolerant crop Portulaca oleracea L. cv. “Su Ma Chi Xian 3” as the test material. A plot experiment was established in coastal saline soils with planting P. a- oleracea (P) and no planting (CK) under three blocks with the different salt levels (S1: 2.16 g/kg; S2: 4.08 g/kg; S3: 5.43 g/kg) to systematically evaluate its salt accumulation capacity and effects on soil physicochemical properties. The results demonstrated that P. oleracea exhibited adaptability across all three salinity levels, with aboveground biomass following the trend PS2 > PS3 > PS1. The ash salt contents removed through harvesting were 1.29, 2.03, and 1.74 t/ha, respectively, in PS1, PS2, and PS3. Compared to no planting, a significant reduction in bulk density was observed in the 0–10 and 10–20 cm soil layers (p < 0.05). A significant increase in porosity by 9.72%, 16.29%, and 12.61% was found under PS1, PS2, and PS3, respectively, in the 0–10 cm soil layer. Soil salinity decreased by 34.20%, 50.23%, and 48.26%, in the 0–10 cm soil layer and by 14.43%, 32.30%, and 26.42% in the 10–20 cm soil layer under PS1, PS2, and PS3, respectively. The pH exhibited a significant reduction under the planting treatment in the 0–10 cm layer. A significant increase in organic matter content by 13.70%, 12.44%, and 13.55%, under PS1, PS2, and PS3, respectively, was observed in the 0–10 cm soil layer. The activities of invertase and urease were significantly enhanced in the 0–10 and 10–20 cm soil layers, and the activity of alkaline phosphatase also exhibited a significant increase in the 0–10 cm layer under the planting treatment. This study indicated that cultivating P. oleracea could effectively facilitate the improvement of coastal saline soils by optimizing soil structure, reducing salinity, increasing organic matter, and activating the soil enzyme system, thereby providing theoretical and technical foundations for ecological restoration and sustainable agricultural utilization of saline–alkali lands. Full article

Oats (Avena sativa L.) are forage grasses moderately tolerant to saline-alkali soil and are widely used for the improvement and utilization of saline-alkali land. Using the oat varieties collected from the Qaidam Basin as experimental materials, based on the analysis data of the main agronomic traits, quality, and soil physical and chemical properties of different oat varieties at the harvest stage. The hay yield of Molasses (17,933.33 kg·hm⁻²) was the highest (p < 0.05), the plant height (113.59 cm) and crude fat (3.02%) of Qinghai 444 were the highest (p < 0.05), the fresh-dry ratio (2.62), crude protein (7.43%), and total salt content in plants (68.33 g·kg⁻¹) of Qingtian No. 1 were the highest (p < 0.05), and the Relative forage value (RFV) of Baler (122.96) was the highest (p < 0.05). In the 0–15 cm and 15–30 cm soil layers of different oat varieties, the contents of pH, EC, total salt, Ca²⁺, Mg²⁺, and HCO₃⁻ showed a decreasing trend at the harvest stage compared to the seedling stage, while the contents of organic matter, total nitrogen, Cl⁻, and SO4²⁻ showed an increasing trend. The contents of K⁺ and Na⁺ maintained a relatively balanced relationship between the seedling stage and the harvest stage in the two soil layers. Qingtian No. 1, Qingyin No. 1, and Molasses all rank among the top three in terms of production performance and soil physical and chemical properties, and they are the oat varieties suitable for cultivation in the research area. Full article

Plants dynamically regulate ions in the tree to defend against abiotic stresses such as drought and saline-alkali, However, it is not clear how ‘Junzao’ jujube regulates ions to maintain a normal life cycle under saline-alkali stress. Therefore, in this study, the roots of 10-year old steer jujube trees were watered using a saline and alkaline gradient solution simulating the main salt (NaCl) and alkali (NaHCO₃) of Aral with NaCl:NaHCO₃ = 3:1 gradient of 0, 60, 180, and 300 mM, and three jujube trees with uniform growth were taken as samples in each treatment plot, and the ion contents of potassium (K), sodium (Na), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn) and carbon (C) in each organ of the fruit at the dot red period (S1) and full-red period (S2) were determined, in order to elucidate the relationship between physiological adaptation mechanisms of saline-alkali tolerance and the characteristics of mineral nutrient uptake and utilisation in jujube fruit. The results showed that under saline-alkali stress, Na was stored in large quantities in the roots, Ca and Mg in the perennial branches at S1, Na and Fe in the leaves at S2, and K, Mg and Mn in the perennial branches. There was no significant difference in the distribution of C content in various organs of ‘Junzao’. Compared with CK (0 mM), under salinity stress, the K content in the leaves was significantly reduced at S1 and S2, and the K/Na ratios remained > 1.0. At S2, under medium and high concentrations of saline-alkali stress (180–300 mM), the K/Na is less than 1, and the ionic homeostasis was disrupted, and the leaves die and fall off, and the Na is excreted from the body. The selective transport coefficients SK/Na, SCa/Na and SMg/Na from root to leaf showed a downward trend at S1, but still maintained positive transport capacity. At S2, this stage is close to leaf fall, the nutrient transport coefficient is less than 1, and a large amount of nutrients are returned to the perennial branches and roots occurred. These results indicated that the mechanism of nutrient regulation and salt tolerance in jujube trees was different at different growth stages. Full article

BEL1-like homeodomain protein 3 (BLH3) plays a crucial role in plant development. However, its involvement in the salt stress response has not been studied. In this study, we investigated the molecular mechanism underlying the response of LpBLH3 to salt stress in Lilium pumilum (L. pumilum) using various techniques, including quantitative PCR (RT-qPCR), determination of physiological indices of plant after Saline-Alkali stress, yeast two-hybrid screening, luciferase complementation imaging (LCI), and chromosome walking to obtain the promoter sequence, analyzed by PlantCARE, electrophoretic mobility shift assay (EMSA), and then dual-luciferase reporter assay(LUC). RT-qPCR analysis revealed that LpBLH3 is most highly expressed in the leaves of L. pumilum. The expression of LpBLH3 peaks at 24 or 36 h in the leaves under different saline stress. Under various treatments, compared to the wild type (WT), the LpBLH3 overexpression lines exhibited less chlorosis and leaf curling and stronger photosynthesis. The overexpression of LpBLH3 can enhance lignin accumulation in root and stem by positively modulating the expression of crucial genes within the lignin biosynthesis pathway. Y2H and LCI analyses demonstrated that LpBLH3 interacts with LpKNAT3. Additionally, EMSA and LUC analyses confirmed that LpBLH3 can bind to the promoter of LpABI5 and upregulate the expression of ABI5 downstream genes (LpCAT1/LpATEM/LpRD29B). In summary, LpBLH3 enhances the plant’s salt tolerance through the ABA pathway and lignin synthesis. This study can enrich the functional network of the BLH transcription factor family, obtain Lilium pumilum lines with good saline-alkali resistance, expand the planting area of Lilium pumilum, and improve its medicinal and ornamental values. Additionally, the functional analysis of the BLH transcription factor family provides new insights into how crops adapt to the extreme growth environment of saline-alkali soils. Full article

Soil salinization hinders plant growth and agricultural production, so breeding salt-tolerant crops is an economical way to exploit saline–alkali soils. However, the specific metabolites and associated pathways involved in salt tolerance of the dandelion have not been clearly elucidated so far. Here, we compared the transcriptome and metabolome responses of 0.7% NaCl-stressed dandelion ‘BINPU2’ (variety A) and ‘TANGHAI’ (variety B). Our results showed that 222 significantly altered metabolites mainly enriched in arginine biosynthesis and pyruvate metabolism according to a KEGG database analysis in variety A, while 147 differential metabolites were predominantly enriched in galactose metabolism and the pentose phosphate pathway in variety B. The transcriptome data indicated that the differentially expressed genes (DEGs) in variety A were linked to secondary metabolite biosynthesis, phenylpropanoid biosynthesis, and photosynthesis–antenna proteins. Additionally, KEGG annotations revealed the DEGs had functions assigned to general function prediction only, post-translation modification, protein turnover, chaperones, and signal transduction mechanisms in variety A. By contrast, the DEGs had functions assigned to variety B as plant–pathogen interactions, phenylpropanoid biosynthesis, and photosynthesis–antenna proteins, including general function prediction, signal transduction mechanisms, and secondary metabolite biosynthesis from the KOG database functional annotation. Furthermore, 181 and 162 transcription factors (TFs) expressed under saline stress conditions specifically were detected between varieties A and B, respectively, representing 36 and 37 TF families. Metabolomics combined with transcriptomics revealed that salt stress induced substantial changes in terpenoid metabolites, ubiquinone biosynthesis metabolites, and pyruvate metabolites, mediated by key enzymes from the glycoside hydrolase family, adenylate esterases family, and P450 cytochrome family at the mRNA and/or metabolite levels. These results may uncover the potential salt-response mechanisms in different dandelion varieties, providing insights for breeding salt-tolerant crop plants suitable for saline–alkali land cultivation. Full article

The management and use of saline–alkaline land is a global concern and research focus. Although there is extensive long-term global research on soil salinization and improvement, systematic summaries of research progress in this field are insufficient. This study, based on the Web of Science (WOS) and incoPat database, analyzes the literature and patents on saline–alkaline land over the past 30 years, sums up research progress and current status, and proposes future directions to lay a foundation for further study. Research hotspots are mainly salt-tolerant plant growth mechanisms and gene expression under salt stress, interactions between salt-tolerant plants and microbes, soil conditioner use, remote sensing monitoring of saline–alkaline land changes, irrigation and drainage techniques, and soil nutrient status and improvement. Saline–alkaline land management research is moving toward integrated application of multiple improvement measures. Priority should be given to developing land remediation technologies and salt-tolerant plant varieties suited to different regions; studying the compatibility among technologies, plant varieties, and cultivation techniques; establishing region- and type-specific integrated management and ecological use methods; and creating comprehensive development plans to boost soil productivity and protect the ecology. Full article

Lonicera caerulea is a wild fruit species with high edible and medicinal value. However, the molecular regulation and metabolic mechanisms of L. caerulea under salt stress are still unclear. Salt stress causes damage to the cell membrane of L. caerulea and induces changes in malondialdehyde content, relative electrolyte leakage, leaves’ stomatal opening, and the water loss rate. It also increases the activity of antioxidant enzymes and the content of soluble sugars. A comprehensive transcriptomic and metabolomic analysis of L. caerulea exposed to salt stress at four different (treatment) time intervals yielded a total of 99,574 unigenes and 1375 metabolites. Among these, 4081, 4042, and 4403 differentially expressed genes (DEGs) were identified in 12 transcriptomes, while 776, 832, and 793 differentially accumulated metabolites (DAMs) were detected in 12 metabolomes. The DEGs play important roles in several signaling pathways, including MAPK signaling, fatty acid metabolism, starch and sucrose metabolism, phenylpropanoid biosynthesis, and plant hormone signal transduction. KEGG pathway enrichment analysis revealed that these DEGs and DAMs are associated with flavonoid and lipid biosynthesis pathways. The combined transcriptomic and metabolomic analyses suggest that flavonoid and fatty acid compounds may be involved in regulating plant responses to salt stress. These findings will lay the foundation for the selection of L. caerulea germplasm resources and the expansion of its cultivation area. These research findings will lay the foundation for the cultivation of salt-tolerant new varieties of L. caerulea and their planting in saline–alkali soils. Full article

Soil salinization severely impacts plant cultivation. Lilium pumilum (L. pumilum) exhibits tolerance to saline–alkali stresses. One Bacillus cereus strain, LpBc-47, possesses the ability of growth promotion and saline–alkali tolerance. The microbial diversity of L. pumilum was assessed through metagenomic sequencing. LpBC-47 obtained from L. pumilum was subjected to physiological and biochemical analyses and whole-genome sequencing. The effects of endophytic bacteria on plants were evaluated by measuring growth parameters, physiological indices, antioxidant enzyme activities, and ROS content. Microbial diversity analysis revealed that the abundance of endophytic bacteria in L. pumilum decreased under saline–alkali conditions, whereas the abundance of Bacillus cereus increased. Physiological and biochemical analysis showed that LpBC-47 has the characteristics of promoting growth and reducing plant damage caused by salt–alkali stress, such as phosphorus solubilization, nitrogen fixation, siderophore production, IAA, and ACC deaminase synthesis. Genomic analysis revealed that LpBC-47 contains growth-associated and stress-alleviation genes. GFP indicated the colonization of LpBc-47 in the roots and bulbs of L. pumilum. The LpBc-47 inoculant plant increased leaf length and dry weight, elevated proline and chlorophyll levels, enhanced antioxidant enzyme activity, and reduced oxidative damage. This study highlights the potential of LpBc-47 for improving plant growth under saline–alkali conditions. Full article