Search Results (431)

Soil salinization poses a major environmental threat to global agriculture, affecting approximately 20% of cultivated land and 50% of irrigated land worldwide. Developing salt–alkali tolerant plant varieties represents a sustainable strategy for utilizing these marginal lands. Phosphatidylinositol-specific phospholipase C (PI-PLC) is a key enzyme in the phosphoinositide signaling system and has been implicated in plant stress responses; however, its function under salt–alkali stress remains poorly understood. In this study, the function of AtPLC1 in salt–alkali tolerance was investigated, and only the atplc1 mutant exhibited a pronounced stress-sensitive phenotype, with AtPLC1 being predominantly expressed in roots and leaves, with peak expression at 6 h of treatment. Compared with wild-type, atplc1 mutants displayed significantly reduced seedling survival, retarded root growth, decreased biomass, water content, chlorophyll, and soluble sugar contents, yet accumulated higher levels of Na⁺, malondialdehyde, H₂O₂, and superoxide anions under salt–alkali stress. Notably, atplc1 mutants showed increased stomatal conductance and decreased leaf surface temperature, as detected by thermal imaging, indicating impaired water regulation. Collectively, our findings demonstrate that AtPLC1 positively regulates salt–alkali tolerance and provides a candidate gene for molecular breeding of stress-resistant crops. Full article

To alleviate the constraints of coastal saline-alkali soil on crop production and explore efficient and low-carbon planting patterns for vulnerable saline land ecosystems, a three-year continuous field experiment was carried out in the coastal saline-alkali farmland of the Yellow River Delta, Dongying City, Shandong Province, China. Using sole maize cropping (CM) as the control, this study systematically compared productivity, energy budget, economic benefit, carbon footprint (CF), and the carbon sustainability index (CSI) of maize–soybean intercropping (M/S) and maize–peanut intercropping (M/P), and further evaluated their comprehensive benefits based on the net ecosystem economic benefit (NEEB). The results showed that compared with CM, the three-year average economic yield of M/S and M/P decreased by 14.6% and 14.0%, with corresponding energy yield reductions of 12.0% and 9.1%. Notably, M/S and M/P significantly increased the maize equivalent yield by 9.4%. Relative to CM, the three-year average net income of M/S and M/P increased by 18.3% and 29.9%, respectively. For carbon-related environmental benefits, M/S and M/P reduced CF per unit maize equivalent yield by 14.0% and 18.1% and CF per unit economic benefit by 13.9% and 18.0%, while increasing the CSI by 6.0% and 8.4%, respectively. Comprehensive evaluation using the Z-score method demonstrated that M/P improved the NEEB by 9.4% and obtained a higher comprehensive score than CM, while M/S produced a marginally lower Z-score than CM. Overall, M/P exhibited the optimal multi-dimensional performance and represents a promising eco-friendly planting pattern for coastal saline-alkali regions. Full article

Severe soil salinization and low fertility significantly constrain sustainable agricultural development in the Yellow River Delta, one of the three major estuarine deltas in China. Despite their ecological importance, the regional-scale spatial interactions between soil salinity and nutrients, particularly regarding their vertical variability, remain poorly understood. This study analyzed 228 soil samples from 76 sites distributed across a distinct salinity gradient, which was determined by constructing a spatial salinity distribution map after sampling. Samples were collected at three depths (0–15, 15–30, and 30–45 cm) to investigate the spatial distribution of soil organic carbon (SOC), total nitrogen (TN), and the C/N ratio, along with their underlying driving factors. SOC and TN exhibited similar spatial patterns, with higher values distributed along both banks of the Yellow River. Horizontally, SOC and TN in the 0–15 cm layer decreased gradually from west to east, whereas the 15–30 cm and 30–45 cm layers showed an opposite trend, increasing eastward. Vertically, SOC and TN contents declined significantly with soil depth (p < 0.05), although the magnitude of this decline varied regionally: the 0–15 cm layer in the western area contained markedly higher nutrient levels than deeper layers, while vertical variation was less pronounced in the eastern and estuarine regions. Both variables were positively associated with total phosphorus (TP), available potassium (AK), soil moisture content (MC), clay content, and pH, but negatively correlated with electrical conductivity (EC), particularly in the 0–15 cm layer. Our results highlight that soil texture, moisture, and salinity affect the spatial heterogeneity and vertical decline of SOC and TN in the Yellow River Delta. Future research should focus on the long-term temporal distribution of the coupling of multiple elements under changing hydrological and salinity regimes. Full article

Soil salinization affects more than 954 Mha of arable land globally, with approximately 10–20 Mha abandoned annually. Conventional engineering and chemical remediation suffer from high water demand, salt re-accumulation, and secondary pollution risks. While this review draws primarily on the extensive body of research from China—where saline–alkali land covers approximately 99.13 Mha—it also incorporates key international case studies for comparative analysis. The review synthesizes biological and physical technologies for saline–alkali land reclamation, identifies critical challenges, and proposes an integrated remediation framework. A systematic search of Web of Science, Scopus, and CNKI databases (2000–2026) yielded 2847 records, of which 41 studies formed the systematic evidence base for the five technology clusters and 41 were retained as background references following the PRISMA framework. Because the search included the Chinese CNKI database and China contains one of the world’s largest saline–alkali land areas, particular emphasis is placed on Chinese case studies, complemented by representative international examples. Data were extracted on technology type, salt removal efficiency, crop yield, and application stage, and synthesized through quantitative cross-technology comparison. Five dominant technical clusters were summarized: (i) gene-based breeding (CRISPR/Cas, MAS) achieving 20–28% yield gains on sodic soils; (ii) halophyte phytoremediation removing 83–91% of soil salts over three growing seasons; (iii) microbial inoculants improving crop salt tolerance by 15–35% under controlled experimental conditions; (iv) agronomic rotations and straw amendment reducing topsoil salinity by 30–50%; and (v) solar-driven interfacial evaporation achieving 91.4% salt removal in a single proof-of-concept field trial at a material cost of approximately USD 0.004 per straw unit. Integrated bio-physical deployment, however, remains at the experimental scale. Combining rapid physical desalination with long-term biological remediation represents a promising research direction that requires systematic field validation before practical deployment. Key knowledge gaps include the long-term edaphic consequences of solar desalination, field-scale reliability of microbial consortia, and absence of regionally validated integrated protocols. We propose a structured roadmap with explicit timelines and policy recommendations to accelerate translation from research to practice. Full article

The selection and breeding of salt-tolerant rice and the use of saline–alkali land for rice cultivation are crucial for food security. However, most studies have focused only on the seedling salt tolerance stage, with little research on the salt tolerance mechanisms during the reproductive growth period. This study selected the salt-tolerant rice line SR17, the salt-tolerant variety SR86, and the salt-sensitive variety IR29 as research subjects. Two salt stress gradients of 0% and 0.5% (7.8 dS m⁻¹) were established. Salt stress was applied continuously from rice transplanting to the maturity stage, and the differences in response mechanisms during the young panicle stage under long-term salt stress were analyzed. The results showed that, under salt stress, SR17 exhibited the least lipid peroxidation and membrane damage, followed by SR86, while IR29 suffered the most severe damage. SR17 and SR86 could reduce oxidative damage and maintain membrane system integrity by activating the antioxidant enzyme system and accumulating soluble proteins. In contrast, the antioxidant system in IR29 was insufficiently activated; this indicates that the adaptability of this variety to salt-induced oxidative stress is relatively poor. The chlorophyll content and most photosynthetic parameters in SR17 showed no significant changes, and leaf gas exchange performance and chlorophyll status were the least affected, whereas IR29 suffered severe damage. Agronomic trait investigation revealed that, compared with the control, SR17 exhibited the smallest reductions in plant height, spikelets per panicle, 1000-grain weight, grain yield per plant, and main spikelet number under salt stress, and the decreases in key yield-related indicators—effective panicle number, grain yield per plant, and seed setting rate—were not significant. This study confirms that SR17 possesses superior salt tolerance and holds potential for further breeding and multi-environment trials, while also providing an important basis for elucidating the physiological mechanisms of salt tolerance during the reproductive stage of rice. Full article

Brackish water irrigation induces secondary soil salinization and severe nitrogen (N) leaching, restricting crop N uptake and grain yield. To address these constraints in coastal saline farmlands, a 140-day field soil column experiment was conducted using coastal saline soil with a salinity of 2.60 g kg⁻¹. We evaluated the individual and interactive effects of three straw return methods (straw removal (S1), straw incorporation (S2), and straw burial (S3)) and three N fertilizer managements (sole conventional urea (N1), 1:1 mixture of polyurethane-coated urea (PCU) and urea (N2), and sole PCU (N3)) on salt dynamics, rice agronomic traits, root morphological characteristics, N use efficiency (NUE), and yield components. The results indicated no significant interactive effects between straw return methods and N fertilizer managements on the measured variables (p > 0.05). S2 significantly decreased soil salinity and exerted the highest efficiency with regard to salt leaching, thereby promoting rice growth (p < 0.05). PCU markedly optimized root development, as evidenced by increased root tip number, branch number, and root crossing density (p < 0.05), which strengthened water and nutrient uptake, ultimately mitigating detrimental impacts of brackish water irrigation on grain yield and NUE. Notably, PCU application ratios showed no significant differences in crop yield (p > 0.05). Overall, straw incorporation combined with a 1:1 ratio of PCU and urea is verified as the optimal strategy for rice cultivation in brackish water-irrigated coastal saline regions. This practice effectively alleviates brackish water-induced salt stress and elevates crop yield and NUE. The outcomes provide solid scientific references and practical guidance for coordinated water–salt–nutrient management and sustainable utilization of fragile coastal saline soils. Full article

Botanical gardens are highly heterogeneous plant systems characterized by high taxonomic diversity, with numerous plant taxa represented within confined areas, and complex ecological interactions that create unique challenges for pest management. Conventional IPM strategies, designed for simplified agroecosystems, often fail to address complex pest pressures in curated environments. Microbial biostimulants have emerged as promising components of sustainable IPM strategies by enhancing plant defense responses, improving stress resilience, and reducing reliance on chemical inputs. This review synthesizes current knowledge on microbial biostimulants, including plant growth-promoting rhizobacteria, arbuscular mycorrhizal fungi and endophytic microorganisms, in modulating plant defense against insect herbivores. These beneficial microbes enhance plant resistance through multiple mechanisms. They activate induced systemic resistance and modulate key phytohormones, including jasmonic acid, salicylic acid, and ethylene. Additionally, they regulate calcium-dependent and reactive oxygen species-mediated defenses. Microbially induced changes in plant secondary metabolites and volatile organic compounds further influence herbivore behavior and trophic interactions. Emphasis is placed on integrating microbial biostimulants into IPM frameworks tailored to botanical gardens. This highlights compatibility with biological control agents and reduced reliance on synthetic pesticides. Despite promising advances, challenges remain, including context-dependent efficacy, host specificity and limited long-term validation. Overall, microbial biostimulants offer a promising tool for enhancing IPM in biodiversity-rich botanical gardens, although further long-term validation is needed to fully assess their sustainability and effectiveness. Full article

Reclaiming coastal saline–alkali land is important for food security, yet little is known about how irrigation and biochar jointly affect the fate of fertilizer nitrogen in these soils. Using ¹⁵N isotope tracing, this field experiment tracked the distribution and recovery of labeled fertilizer in a soil–sunflower system under three irrigation quotas (8, 16, and 24 mm per event, applied every 10 days) and four biochar rates (0, 3, 5, and 7 t·ha⁻¹). After harvest, approximately 73% of residual ¹⁵N remained in the 0–40 cm topsoil, with organic-bound N as the dominant fraction (72–74%). Mineral ¹⁵N increased with soil depth, indicating downward movement with water flow. Within sunflower plants, labeled N accumulation followed the order flower head > stem > leaf > root, with heads containing 11–12 times more ¹⁵N than roots, confirming active transport to reproductive organs. Overall ¹⁵N use efficiency ranged from 18.8% to 24.9% across treatments. Increasing biochar rate enhanced ¹⁵NUE by up to 28.2% under the same irrigation regime, whereas raising irrigation from 16 mm to 24 mm reduced ¹⁵NUE by 3.2–3.8%. Mass balance analysis showed that moderate irrigation (16 mm) combined with high biochar (7 t·ha⁻¹) achieved the highest plant ¹⁵N recovery (24.9%), maintained 70.0% of labeled N in soil, and limited unaccounted ¹⁵N to only 5.1%. These findings demonstrate that integrated water–biochar management can optimize fertilizer N retention and crop uptake in coastal saline–alkali soils, providing a scientific basis for precision fertilization in these degraded lands. Full article

In this study, we synthesized a lignin-based superabsorbent hydrogel (LWR) to relieve severe evaporation and structural degradation in inland saline–alkali soils. The LWR was prepared via free-radical graft copolymerization of calcium lignosulfonate (CL) and acrylic acid (AA), with its swelling performance optimized systematically. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to characterize its chemical and microscopic structure, and the soil column was exposed to three drying–wetting cycles to explore the effects of hydrogel dosage on soil evaporation and crack evolution. CL may graft into polyacrylic acid under optimal conditions (60% AA neutralization, 4% CL, 1% initiator, and 0.03% crosslinker) to form a porous hydrophilic 3D network. Consequently, the optimized LWR achieved swelling capacities of 1480 g/g and 122 g/g in deionized water and a 0.9% NaCl solution, respectively, showing high water absorbency and salt resistance. During cyclic drying and wetting, soil evaporation was first dominated by the hydrogel’s water retention capabilities; then, it was controlled physically by soil surface cracks. A moderate LWR dosage of 0.3% was used to maintain stable water retention in soil and the intact soil structure, which likely occurred due to its strong water absorption and hypothesized calcium ion bridging anti-cracking interactions. This work overturns the traditional view that a higher hydrogel dosage yields better water retention. Instead, it highlights the importance of conducting a long-term joint evaluation of the hydrogel’s water retention capacity and its resistance to soil dry–wet deformation stress, thereby offering theoretical support for eco-friendly water retention agent design and saline–alkali land remediation. Full article

A systematic evaluation of salt tolerance at the seedling stage was conducted using 143 maize inbred lines under a 150 mM mixed-salt solution (NaCl:Na₂SO₄ = 9:1, EC = 16.78 dS/m) that mirrors the ionic composition of saline groundwater in the Yellow River Delta. The comprehensive salt tolerance index (D value) ranged from 0.15 to 0.85 across the population, with the elite line B114 exhibiting the highest D value (0.835) and the sensitive line PHT55 ranking near the bottom. Under salt stress, B114 displayed remarkable growth stability, with plant height decreasing by only 25.9%, fresh weight by 13.3%, and dry weight remaining unchanged, whereas PHT55 suffered severe growth inhibition (plant height: 61.5% decrease; fresh weight: 63.2% decrease; dry weight: 33.3% decrease). Time-series RNA-seq of root tissues across four time points (5, 8, 11, and 14 days) revealed markedly distinct transcriptional dynamics: B114 exhibited relatively stable temporal regulation (2261–9124 DEGs), whereas PHT55 showed a pronounced early transcriptional burst that progressively intensified (3728–10,108 DEGs). Using random forest-based machine learning, 50 core salt tolerance-related genes were unbiasedly identified from 16,194 significantly differentially expressed genes. Functional enrichment analysis revealed that these genes were primarily involved in redox regulation, ion homeostasis maintenance, and stress signal transduction pathways. qRT-PCR validation confirmed biphasic expression patterns, with Zm00001d024160 showing the strongest early induction (48-fold at 5 h). This study established a maize salt tolerance evaluation system closely aligned with field conditions and demonstrated that coordinated temporal transcriptional regulation represents a core molecular mechanism underlying high salt tolerance in maize. The elite salt-tolerant germplasm and key candidate genes identified here provide valuable genetic resources and a theoretical foundation for molecular breeding of salt-tolerant maize adapted to saline-alkaline soils. Full article

Puccinellia tenuiflora is a perennial halophytic grass commonly regarded as a pioneer species for the ecological restoration of saline–alkali land. Its adaptive capacity and subsequent utilization value are shaped by interacting structural, physiological, molecular, ecological, and management-related factors. This review summarizes recent studies on saline–alkali tolerance in P. tenuiflora, with emphasis on root structural barriers, Na⁺/K⁺ homeostasis, osmotic adjustment, organic-acid metabolism, antioxidant defense, ion transport, and multi-omics regulation. To better understand the integrated stress response, we propose a functional framework that distinguishes first-line defenses from downstream cellular repair mechanisms. First-line defenses include root apoplastic barriers (Casparian strips and suberization) that restrict Na⁺ entry, plasma-membrane Na⁺/H⁺ antiporters (e.g., SOS1) that mediate active Na⁺ exclusion, and K⁺-retention mechanisms (e.g., AKT1, HKT2;1) that preserve cytosolic K⁺/Na⁺ homeostasis—these operate rapidly to prevent ion imbalance at the onset of stress. Downstream repair and acclimation mechanisms include osmotic adjustment via compatible solutes (e.g., proline, glycine betaine), organic-acid accumulation (especially citric acid) for pH regulation and chelation, ROS scavenging systems, and proteomic/phosphoproteomic reprogramming that repair stress-induced damage and restore metabolic balance. Furthermore, saline–alkali stress involves both short-term osmotic shock and long-term ionic toxicity, and available evidence suggests a temporal shift in the relative importance of these mechanisms: osmotic adjustment and rapid ion exclusion dominate during the initial hours to days of stress, whereas organic-acid metabolism, ROS buffering, and molecular reprogramming become increasingly important during prolonged exposure, sustaining tissue integrity and enabling long-term persistence. Current evidence indicates that saline–alkali tolerance in P. tenuiflora results from the combined action of several processes, including restricted Na⁺ entry, K⁺ retention, organic-acid accumulation, reactive oxygen species homeostasis, and organ-specific molecular responses. This review also discusses the significance of P. tenuiflora in community establishment, saline–alkali land restoration, and post-restoration forage utilization. Field studies and limited feeding trials suggest that P. tenuiflora can provide biomass and utilization potential after community stabilization. However, based on current evidence, it is more appropriate to define its forage value as a post-restoration utilization extension rather than as that of a fully developed specialized forage crop. Further studies are required on nutritional quality, mineral-element safety, long-term field management, and animal feeding validation. Full article

Saline–alkali stress is a widespread abiotic stress that severely impairs crop growth and yield formation. Iron Chlorin e6 (ICe6), a novel plant growth regulator, is essentially a chlorophyll derivative, and possesses potential application value in regulating plant chlorophyll metabolism and improving plant stress resistance. In this study, the saline–alkali-sensitive soybean cultivar Henong 95 and saline–alkali-tolerant soybean cultivar Hefeng 50 were used as experimental materials, and foliar spraying with 120 nmol/L ICe6 was conducted at the R1 stage. The results indicated that relative to CK, SA treatment markedly inhibited soybean growth, accompanied by reduced antioxidant capacity, excessive reactive oxygen species (ROS) accumulation and significantly lowered photosynthetic pigment content. Carbohydrate accumulation was substantially suppressed, which ultimately resulted in yield reduction (HN95: −12.31%; HF50: −11.08%). ICe6 treatment mitigated saline–alkali-induced growth inhibition in soybean plants, as reflected by markedly restored antioxidant indices, sharply decreased malondialdehyde (MDA), H₂O₂, and O₂⁻ levels, and notably increased leaf area (HN95: +49.72%; HF50: +19.82%) and chlorophyll content (HN95: +36.06%; HF50: +90.75%). Combined transcriptomic and metabolomic profiling showed that, relative to the SA control, ICe6 treatment led to the identification of 2896 DEGs in HN95 and 3530 DEGs in HF50, with significant enrichment in photosynthesis- and chlorophyll metabolism-related pathways, e.g., GO:0009765 (photosynthesis, light harvesting). Differential metabolites were chiefly enriched in isoflavonoid biosynthesis—a source of antioxidants—and amino acid biosynthesis, which governs chlorophyll precursor synthesis. These findings suggest that ICe6 may enhance chlorophyll content by modulating the expression of genes involved in chlorophyll metabolism, contributing to light capture and chlorophyll biosynthesis, facilitating carbohydrate accumulation and ultimately contributing to increased yield under saline–alkali stress (HN95: +5.74%; HF50: +5.83%). Full article

Paramarasmius mesosporus is a wild edible mushroom with a strong aroma and high culinary value, capable of growing at temperatures up to 36 °C. However, its domestication system and the genetic basis of its sexual reproduction remain largely unexplored. In this study, fresh fruiting bodies of P. mesosporus were collected from the rhizosphere of Imperata spp. in saline–alkali land in Hebei Province, China. The species was successfully domesticated for the first time, and fruiting bodies were harvested 7–10 days after spawning. A chromosome-level genome of the monokaryotic strain ‘Q2’ was assembled using whole-genome sequencing, transcriptome analysis, and Hi-C technology, with a total size of 46.57 Mb that was anchored onto 11 pseudochromosomes at a mounting rate of 95.18%. The mating-type system was identified as a typical tetrapolar heterothallic type, with the MAT A and MAT B loci located on chromosomes 2 and 10, respectively. The MAT A locus encodes HD1, HD2, MIP, and β-fg, among which tr-HD1 was found to be pseudogenized due to domain truncation. The MAT B locus comprises seven pheromone receptor genes and seven pheromone precursor genes arranged in an interspersed pattern. Based on these genomic features, a preliminary MAPK signaling pathway model was proposed to elucidate the molecular regulation of sexual reproduction. This study achieved the first artificial domestication and cultivation of P. mesosporus. systematically elucidated genomic characteristics and mating-type molecular mechanisms of this species were systematically elucidated, providing a theoretical foundation for hybrid breeding, molecular marker-assisted selection, and genetic improvement. These findings hold significant scientific and applied value for germplasm innovation and industrial development of this rare edible mushroom. Full article

Soil salinization and alkalization severely limit agricultural sustainability in alpine regions. The integrated responses of oats to complex saline–alkali stress, covering phenotypic, physiological, and metabolomic alterations, remain poorly elucidated. This study aimed to clarify the synergistic adaptive mechanisms of oats with differential saline–alkali tolerance. Three oat varieties with distinct tolerance levels, including the tolerant cultivar Meida, the moderately tolerant cultivar Qingtian No. 2, and the sensitive cultivar Qinghai Sweet Oat, were treated with a 150 mmol·L⁻¹ mixed saline–alkali solution (Na₂SO₄:NaCl:NaHCO₃ = 2:1:1, pH 8.65) to simulate the natural alpine soil environment of Qinghai Province. Compound saline–alkali stress markedly inhibited oat growth and aggravated cellular oxidative damage. The tolerant cultivar effectively alleviated stress injury by improving antioxidant enzyme activities and accumulating osmoprotectants. A total of 396 core differential metabolites were screened in this study, and flavonoid biosynthesis was identified as a conserved core pathway for oat stress resistance. Tolerant oat varieties simultaneously activated defense responses and energy metabolism to adapt to stress conditions. In contrast, sensitive varieties only depended on basal metabolic adjustments to cope with stress. These findings clarify the differential adaptive strategies of oats under saline–alkali stress. They provide key metabolic marker resources and a solid theoretical basis for the breeding and cultivation of salt–alkali-tolerant oats in alpine saline–alkali land. Full article

Sexual reproduction of the ascomycetous fungus Magnaporthe oryzae is reported to be regulated by illuminance and temperature, but their temporal interaction during perithecial production remains unclear. Here, we performed full-factorial condition transfer assays (illuminance: low/0 lx, medium/1000 lx, or high/5000 lx; temperature: low/19 °C or high/25 °C) using a pair of high-fertility M. oryzae isolates collected from green bristlegrass to characterize sequential and combinatorial effects of illuminance and temperature on perithecial production. We found that perithecial production showed a strong positive correlation with illuminance at 19 °C, and continuous darkness completely abolished their fertility. Early illuminance priming promotes perithecial production in a dose-dependent manner, whereas prolonged initial darkness for over four days results in remarkable reductions in perithecial production. Moreover, pre-transfer at 25 °C promoted perithecial production under 1000 lx or darkness, and post-transfer at 19 °C sustained or enhanced perithecial production. We also found that plates initially cultured at 5000 lx maintain high capacity for perithecial production across most post-transfer environments, especially under the post-transfer condition at 19 °C with over 2000 perithecia per plate. Taken together, our study demonstrates that combinations of high illuminance and low temperature promote perithecial production of the green bristlegrass blast fungus M. oryzae under laboratory conditions, providing alternative insights into the roles of environmental factors in fungal sexual reproduction. Full article