Search Results (287)

The utilization of saline–alkali land for rice cultivation is critical for global food security. However, most existing studies on rice salt tolerance focus on the seedling stage, with limited insights into tolerance mechanisms during reproductive growth, particularly at the panicle initiation stage (PI). Leveraging precision salinity-control facilities, this study imposed four salt stress gradients (0, 3, 5, and 7‰) to dissect the differential response mechanisms of six rice varieties (YXYZ: Yuxiangyouzhan, JLY3261: Jingliangyou3261, SLY91: Shuangliangyou91, SLY138: Shuangliangyou138, HLYYHSM: Hualiangyouyuehesimiao, and SLY11:Shuangliangyou111) during PI. The results revealed that increasing salinity significantly reduced tiller number (13.14–68.04%), leaf area index (18.58–57.99%), canopy light interception rate (11.91–44.08%), and net photosynthetic rate (2.63–52.42%) (p < 0.001), accompanied by reactive oxygen species (ROS)-induced membrane lipid peroxidation. Integrative analysis of field phenotypic and physiological indices revealed distinct adaptation strategies: JLY3261 rapidly activated antioxidant enzymes under 3‰ salinity, alleviating lipid peroxidation (no significant difference in H₂O₂ or malondialdehyde content compared to 0‰ salinity) and maintaining tillering and aboveground biomass. SLY91 tolerated 7‰ salinity via CAT/POD-mediated lipid peroxide degradation, with H₂O₂ and malondialdehyde contents increasing initially but decreasing with escalating stress. These findings highlight genotype-specific antioxidant strategies underlying salt-tolerance mechanisms and the critical need for integrating phenomics–physiological assessments at reproductive stages into salt-tolerance breeding pipelines. Full article

Maize is an essential staple food, and its genetic diversity plays a central role in breeding programs aimed at developing climate-adapted cultivars. Constructing a representative core germplasm set is necessary for the efficient conservation and utilization of maize genetic resources. In this study, we analyzed 588 cultivated maize accessions using agronomic traits such as plant morphology and yield traits such as ear characteristics and single-nucleotide polymorphisms (SNPs) to assess molecular diversity and population structure and to construct a core collection. Nineteen phenotypic traits were evaluated, revealing high genetic diversity and significant correlations among most quantitative traits. The optimal sampling strategy was identified as “Mahalanobis distance + 20% + deviation sampling + flexible method.” Whole-genome genotyping was conducted using the Maize6H-60K liquid phase chip. Population structure analysis, principal component analysis, and cluster analysis divided the 588 accessions into six subgroups. A core collection of 172 accessions was selected based on both phenotypic and genotypic data. These were further evaluated for salt–alkali tolerance during germination, and cluster analysis classified them into five groups. Sixty-five accessions demonstrated salt–alkali tolerance, including 18 with high resistance. This core collection serves as a valuable foundation for germplasm conservation and utilization strategies. Full article

Salt stress is a major constraint to seed germination and early seedling growth in rice, affecting crop establishment and productivity. To understand the mechanisms underlying salt tolerance, we investigated two rice varieties with contrasting responses as follows: salt-tolerant sea rice 86 (SR86) and salt-sensitive P559. Germination assays under increasing NaCl concentrations (50–300 mM) revealed that 100 mM NaCl induced clear phenotypic divergence. SR86 maintained bud growth and showed enhanced root elongation under moderate salinity, while P559 exhibited significant growth inhibition. Transcriptomic profiling of buds and roots under 100 mM NaCl identified over 3724 differentially expressed genes (DEGs), with SR86 showing greater transcriptional plasticity, particularly in roots. Gene ontology enrichment revealed tissue- and genotype-specific responses. Buds showed enrichment in photosynthesis-related and redox-regulating pathways, while roots emphasized ion transport, hormonal signaling, and oxidative stress regulation. SR86 specifically activated genes related to photosystem function, DNA repair, and transmembrane ion transport, while P559 showed activation of oxidative stress-related and abscisic acid (ABA)-regulated pathways. Hormonal profiling supported transcriptomic findings as follows: both varieties showed increased gibberellin 3 (GA3) and gibberellin 4 (GA4) levels under salt stress. SR86 showed elevated auxin (IAA) and reduced jasmonic acid (JA), whereas P559 maintained stable IAA and JA levels. Ethylene precursor and salicylic acid levels declined in both varieties. ABA levels rose slightly but not significantly. These findings suggest that SR86’s superior salt tolerance results from rapid growth, robust transcriptional reprogramming, and coordinated hormonal responses. This study offers key insights into early-stage salt stress adaptation and identifies molecular targets for improving stress resilience in rice. Full article

Concerning rising salinity and declining freshwater supply in the U.S. Southern Great Plains, alternative crop production choices using marginal saline irrigation water are irresistible. The study investigated plant traits related to salt tolerance in greenhouse canola (Brassica napus L.) in 2022 and 2023. Spring and winter canola, including ten genotypes each, were evaluated at six salinity levels (0; control, 2, 4, 6, 8, and 8 dS m⁻¹ EC). Plant height, stem mass, leaf area, and specific leaf area (SLA) showed a negative linear response, while quadratic relationships were observed in biomass and leaf mass with increased salinity levels. Substantial negative salinity impacts on plant traits occurred at ≥6 dS m⁻¹ EC (p ≤ 0.01) except for SLA. Overall, winter canola genotypes: Athena, Ericka, CP320WRR, CP115W, and CP225WRR, and spring genotypes: Empire, Monarch, Profit, and Westar, were relatively more salt-tolerant than others. Spring canola showed greater salinity tolerance than winter canola. Salinity stress resulted in differential responses of greater leaf mass in winter canola but more efficient leaf area production in spring canola. SLA and stem mass were highly correlated with most parameters. Findings indicate SLA and stem mass are potential salt tolerance traits in canola and warrant further investigations and validation. Full article

Growth traits are the most important economic traits in red tilapia (Oreochromis spp.) production, and are the main targets for its genetic improvement. Increasing salinity levels in the environment are affecting the growth, development, and molecular processes of aquatic animals. Red tilapia tolerates saline water to some degree. However, few credible genetic markers or potential genes are available for choosing fast-growth traits in salt-tolerant red tilapia. This work used genome-wide association study (GWAS) and RNA-sequencing (RNA-seq) to discover genes related to four growth traits in red tilapia cultured in saline water. Through genotyping, it was determined that 22 chromosomes have 12,776,921 high-quality single-nucleotide polymorphisms (SNPs). One significant SNP and eight suggestive SNPs were obtained, explaining 0.0019% to 0.3873% of phenotypic variance. A significant SNP peak associated with red tilapia growth traits was located on chr7 (chr7-47464467), and plxnb2 was identified as the candidate gene in this region. A total of 501 differentially expressed genes (DEGs) were found in the muscle of fast-growing individuals compared to those of slow-growing ones, according to a transcriptome analysis. Combining the findings of the GWAS and RNA-seq analysis, 11 candidate genes were identified, namely galnt9, esrrg, map7, mtfr2, kcnj8, fhit, dnm1, cald1, plxnb2, nuak1, and bpgm. These genes were involved in ‘other types of O-glycan biosynthesis’, ‘glycine, serine and threonine metabolism’, ‘glycolysis/gluconeogenesis’, ‘mucin-type O-glycan biosynthesis’ and ‘purine metabolism signaling’ pathways. We have developed molecular markers to genetically breed red tilapia that grow quickly in salty water. Our study lays the foundation for the future marker-assisted selection of growth traits in salt-tolerant red tilapia. Full article

Rice (Oryza sativa L.), a staple food for over half of the global population, plays a pivotal role in food security. Among its two primary groups, japonica and indica, temperate japonica varieties are particularly valued for their high-quality grain and culinary uses. Although some of these varieties are adapted to cooler climates, they often suffer from reduced productivity or increased disease susceptibility when cultivated in warmer productive environments. These limitations underscore the need for breeding programs to incorporate biotechnological tools that can enhance the adaptability and resilience of the plants. However, New Genomic Techniques (NGTs), including CRISPR-Cas9, require robust in vitro systems, which are still underdeveloped for temperate japonica genotypes. In this study, we developed a reproducible and adaptable protocol for protoplast isolation and regeneration from the temperate japonica cultivars ‘Ónix’ and ‘Platino’ using somatic embryos as the starting tissue. Protoplasts were isolated via enzymatic digestion (1.5% Cellulase Onozuka R-10 and 0.75% Macerozyme R-10) in 0.6 M AA medium over 18–20 h at 28 °C. Regeneration was achieved through encapsulation in alginate beads and coculture with feeder extracts in 2N6 medium, leading to embryogenic callus formation within 35 days. Seedlings were regenerated in N6R and N6F media and acclimatized under greenhouse conditions within three months. The isolated protoplast quality displayed viability rates of 70–99% within 48 h and supported transient PEG-mediated transfection with GFP. Additionally, the transient expression of a gene editing CRISPR-Cas9 construct targeting the DROUGHT AND SALT TOLERANCE (OsDST) gene confirmed genome editing capability. This protocol offers a scalable and genotype-adaptable system for protoplast-based regeneration and gene editing in temperate japonica rice, supporting the application of NGTs in the breeding of cold-adapted cultivars. Full article

Against the background of increasing global soil salinity, exogenous salicylic acid (SA) and melatonin (MT) have attracted much attention for their potential in regulating plant stress tolerance and have become an important research direction for the development of green and sustainable agriculture. In this study, the alleviating effects of different concentrations of SA (100–900 μM) and MT (100–900 μM) on salt stress (50 mM NaCl) and their physiological mechanisms were systematically investigated using the Tianjin specialty rice, Xiaozhan rice, as the research object. The results showed that salt stress significantly inhibited the germination and seedling growth of the two varieties, in which the salt-sensitive variety Jinchuan No. 1 showed significantly higher decreases in root length, plant height, and biomass (54.7–69.1%) than the salt-tolerant variety Jindao 919 (4.0–28.9%). Exogenous SA and MT were effective in mitigating salt stress injury, but there were genotypic differences in their pathways of action. For the first time in japonica rice, the genotype specificity of the SA/MT response was clearly revealed: SA dominated the response of salt-tolerant varieties by enhancing antioxidant defences, whereas MT optimized the overall performance of the salt-sensitive varieties through scavenging of reactive oxygen species, and in addition, it was further determined that SA and MT exhibited optimal mitigating effects on both varieties in the 300–700 μM concentration range, showing the best mitigation effect for both varieties. This finding provides an important theoretical basis and technological paradigm for precision stress tolerance cultivation of saline rice, and the application of appropriate concentrations of SA/MT according to genotype specificity to reduce the dependence on agrochemicals is of practical value in promoting green and sustainable production in saline agriculture. Full article

Salt stress severely constrains global crop productivity. However, most sweet corn cultivars exhibit weak tolerance to salt stress. In this study, two sweet corn CSSLs, salt-tolerant line D55 and salt-sensitive line D96, were selected as materials. We conducted comparative phenotyping and physiological profiling of seedlings under salinity treatment, and transcriptome analysis was carried out by sampling root tissues at 0 h, 4 h, 12 h, and 72 h post-treatment. The results indicated that D55 exhibited enhanced seedling height, root length, fresh weight, relative chlorophyll content, and antioxidant enzyme activities, while showing reduced malondialdehyde accumulation in comparison to D96. Pairwise comparisons across time points (0 h, 4 h, 12 h, 72 h) identified 6317 and 6828 differentially expressed genes (DEGs) in D55 and D96. A total of 49 shared DEGs across four time points were identified in D55 and D96, which were enriched in 12 significant Gene Ontology (GO) terms. Only eight DEGs were shared between genotypes across all comparisons. Transcriptomic analysis revealed 1281, 1946, and 1717 DEGs in genotypes D55 and D96 at 4 h, 12 h, and 72 h post-salt treatment, respectively. Genes associated with reactive oxygen species (ROS) homeostasis, phenylpropanoid metabolism, cutin, suberin and wax biosynthesis, and benzoxazinoid synthesis exhibit enhanced sensitivity in the salt-tolerant genotype D55. This leads to an enhanced ROS scavenging capacity and the establishment of a multi-layered defense mechanism. Additionally, brassinosteroid (BR), gibberellin (GA), and abscisic acid (ABA) and auxin-related genes exhibited different responses to salt stress in sweet corn. A hypothetical model, which established a multi-layered salt adaptation strategy, by integrating ROS detoxification, osmotic balance, and phytohormone signaling, was put forward. By integrating transcriptome and differential chromosomal fragment data, our findings identify 14 candidate genes for salt tolerance, providing potential ideal target genes in breeding to improve salt tolerance in sweet corn. Full article

Background/Objective: Salinity is a growing problem affecting a large portion of global agricultural land, particularly in areas where water resources are scarce. The objective of this study was to provide physiological and molecular information on salt-tolerant citrus rootstocks to mitigate the detrimental effects of salinity on citriculture. Methods: Ten accessions belonging to eight Citrus species and four to Poncirus trifoliata Raf. were tested for salinity tolerance (0 and 15 mM NaCl for 1 year) in terms of vegetative and Cl⁻ tissue distribution traits. In addition, most accessions were evaluated for leaf Na⁺ and other cations. Results: All salt tolerant accessions tended to restrict the leaf Cl⁻ content, although in a lower degree than the Cleopatra mandarin. However, differences in their ability to restrict leaf [Na⁺] were evident, contributing to a classification of trifoliate and sour orange accessions that matched their genotypic grouping based on allele sharing at a marker targeting candidate gene coding for the NPF5.9 transporter within LCL-6 quantitative trait locus. Conclusions: Our markers targeting LCl-6 candidate genes coding for NPF5.9, PIP2.1, and CHX20 (citrus GmSALT3 ortholog) could be efficient tools for managing the detected salt tolerance diversity in terms of both Cl⁻ and Na⁺ homeostasis in rootstock breeding programs derived from these species, in addition to Citrus reshni. Full article

Salinity is a critical abiotic stress influencing plant growth. However, its effect on grasspea (Lathyrus sativus L.) remains insufficiently explored. The present study screened 24 germplasm accessions representing 11 Lathyrus species at the seedling stage at 0, 100, and 150 mM NaCl concentrations using a hydroponic system. Our findings indicated that salt stress had a significant effect on all assessed traits, including a reduction in relative leaf water content and SPAD index, a decline in the length and biomass of shoots and roots, and an elevation in their corresponding dry contents. The grasspea accessions displayed a wide range of responses to salt stress. This variation allowed the identification of nine tolerant accessions at both stress levels, belonging to cultivated and wild relative species, specifically LAT 495, IG 65117, L.OCH, IG 65273, IG 64931, IG 114526, IG 64892, IG 66065, and IG 65018. Four accessions, namely IG 110632, IG 114531, IG 65133, and IG 66026, demonstrated tolerance only at 100 mM NaCl concentration. Through identifying these promising accessions, our research offers crucial insights for the initial screening of tolerant genotypes in grasspea, setting the stage for further studies to decipher the intricate mechanisms of salinity tolerance in these accessions. Full article

Wheat, a cold-tolerant crop, suffers substantial yield and quality losses under heat stress, yet the genetic mechanisms underlying thermotolerance remain understudied. We characterized TaCOBL6A2, a novel COBRA-like gene on wheat chromosome 6A encoding a glycosylphosphatidylinositol (GPI)-anchored protein with a conserved COBRA domain, and performed subcellular localization, tissue-specific expression, and stress response analyses to investigate its function. Functional validation was conducted based on TaCOBL6A2 overexpression in Arabidopsis and transcriptomic profiling. Additionally, a haplotype analysis of wheat varieties was performed to associate genotypes with heat stress phenotypes. The results show that TaCOBL6A2 is localized to the plasma membrane, the cell wall, and the nucleus, with the highest expression in early-stage grains. Its transcription was strongly induced by heat stress, exceeding that in response to cold, salt, or drought. Its overexpression in Arabidopsis enhanced thermotolerance and activated heat shock proteins (HSPs) and oxygen homeostasis pathways. The elite haplotype, Hap1, was associated with improved seedling growth and elevated antioxidant enzyme activity under heat stress. Our findings reveal that TaCOBL6A2 is a key regulator of wheat heat tolerance and could be used as a molecular target for breeding climate-resilient cultivars. Full article

Developing crop varieties with combined salinity and waterlogging tolerance is essential for sustainable agriculture and food security in regions affected by these stresses. This process requires an efficient method to rapidly and accurately assess the tolerance of multiple genotypes to these stresses. Our study examined the use of a pot trial in combination with the assessment of multiple traits to assess the tolerance of 100 wheat (Triticum aestivum L.) genotypes sourced from around the world to these combined stresses. The stresses were imposed on the plants using 100 mM NaCl and by submerging the root systems of the plants in their bathing solutions. The data gathered were subjected to principal component analysis (PCA), and an integrated score (IS) for each genotype was calculated based on multiple morpho-physiological traits; the score was used to rank the genotypes with respect to tolerance or susceptibility. There were significant differences among the 100 wheat genotypes in terms of the relative reductions in their growth parameters and chlorophyll contents, suggesting a rich, genetic diversity. To assess the accuracy of this methodology and to gain insight into the causes of tolerance or susceptibility, the five most tolerant (Misr4 (W85), Corack (W41), Kzyl-Sark (W94), Hofed (W57), BAW-1157 (W14)), and two least tolerant (Livingstong (W60) and Sunvale (W73)) genotypes were selected based on their IS and PCA analysis. These genotypes were then grown hydroponically with and without salinity stress. The data from this second trial were again subjected to PCA, and their IS were calculated; there was reasonable agreement in the ranking of the genotypes between the two trials. The most tolerant genotype (W85; Misr4 from Egypt) and most susceptible genotype (W73; Sunvale from Australia) were then examined in further detail in a third trial. Plants of Misr4 (W85) had lower Na⁺/K⁺ ratios, higher superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase activities, and higher glutathione concentrations. As a result, plants of Misr4 (W85) had lower concentrations of reactive oxygen species (H₂O₂ and O₂^•−) and malondialdehyde than those of Sunvale (W73). This study offers an efficient methodology for the assessment of multiple sources of germplasm for stress tolerance. It has also identified germplasm that can be used for future breeding work and for further research on the mechanisms of tolerance and susceptibility to combined salinity and waterlogging stresses. Full article

Irrigation water salinity poses escalating threats to agricultural sustainability in degraded agroecosystems. This study has investigated the effects of magnetized versus non-magnetized saline water on the soil physicochemical properties and forage productivity of three Lotus corniculatus L. genotypes (salt-sensitive ecotype 232098, moderately salt-tolerant San Gabriel, and salt-tolerant Estanzuela Ganador) in arid northern Mexico. A split-plot randomized block design with three replicates assigned saline water treatments (magnetized [MWT] vs. non-magnetized [NMWT]) to main plots and genotypes to subplots. After one year of irrigation, MWT significantly attenuated soil salinization, evidenced by 23% lower electrical conductivity (5.8 vs. 7.2 dS·m⁻¹), a 26% reduced sodium adsorption ratio (6.2 vs. 8.4), and a 41% decreased sodium concentration (20.7 vs. 35.4 meq·L⁻¹) compared to NMWT (p < 0.05). Although agronomic traits (stem dimensions, leaf area index, and rhizome proliferation) exhibited salt sensitivity from the third season onward, fresh biomass yield remained unaffected by water treatment. Genotypic differences dominated productivity. Estanzuela Ganador achieved superior biomass in both seasons (288.9 g/rhizome in fall; 184.2 g in winter), outperforming San Gabriel by 15.8% and ecotype 232098 by 56.8% (p < 0.05). These findings demonstrate that magnetized saline water irrigation effectively mitigates soil salinity progression, while genotype selection critically determines forage productivity under arid conditions. Estanzuela Ganador emerges as the optimal cultivar for saline irrigation systems in water-scarce regions. Full article

Abiotic stresses like heat and salinity challenge crop production, but cultivar-specific adaptability and tolerance inducers can mitigate their impact. This study examined the growth and biochemical responses of five tomato varieties (Adeleza F1, Saint Anna F1, Goudski F1, Bronski F1, and Dunk F1) to thermopriming followed by salinity stresses. Thermopriming initially promoted growth but had variable effects on plant performance under combined stresses. Adeleza F1 and Bronski F1 were less affected, while Goudski F1 and Dunk F1 exhibited delayed development and reduced biomass under salinity stress. Thermopriming enhanced leaf chlorophyll content and antioxidant capacity in some varieties but inconsistently influenced leaf phenolics and flavonoids. Notably, increased flavonoid and anthocyanin accumulation in certain varieties suggests improved stress tolerance, albeit at the cost of growth. However, a consistent priming effect was not observed across all varieties, as combined heat and salt stress had a more severe impact than individual stresses. These findings highlight genotype-specific responses, underscoring the need for optimized (thermo-)priming protocols that balance growth and defense. This study provides valuable insights into the complex interplay of heat and salinity stress in tomatoes, emphasizing targeted strategies for enhancing crop resilience and informing future breeding programs. Full article

Salinity is one of the most important abiotic stress factors affecting wheat production. Salt in the soil is a major environmental stressor that can affect the bacterial community in the rhizosphere of wheat. The bacteria in the plant’s rhizosphere promote growth and stress tolerance, which vary by variety and location. Nevertheless, the soil harbors some of the most diverse microbial communities, while the rhizosphere selectively recruits according to the needs of plants in a complex harmonic regulation. The microbial composition and diversity under normal and saline conditions were assessed by comparing the rhizosphere of wheat with soil using 16S rRNA gene amplicon sequencing, highlighting the number of operational taxonomic units (OTUs). Taxonomic analyzes showed that the bacterial community was predominantly and characteristically composed of the phyla Proteobacteria, Actinobacteria, Bacteroidetes, Firmicutes, Verrucomicrobia, and Fibrobacteres, representing the usual microbial profile for the rhizosphere of wheat. Idiomarinaceae, Rheinheimera, Halomonas, and Pseudomonas (a strain of Proteobacteria), together with Gracilibacillus (a strain of Firmicutes Bacilli), were recognized as microbial signatures for the rhizosphere microbiome under saline conditions. This was observed even with unchanged soil type and genotype. These patterns occurred despite the same soil type and genotype, with salinity being the only variable. The collective action of these bacterial phyla in the rhizosphere not only improves nutrient availability but also induces systemic resistance in the plants. This synergistic effect improves plant resistance to salt stress and supports the development of salt-tolerant wheat varieties. These microbial signatures could improve our understanding of plant–microbe interactions and support the development of microbiome-based solutions for salt stress. Full article