Alfalfa (Medicago sativa) is a perennial forage crop with significant economic and ecological significance. If alfalfa can be planted in saline-alkali land, it will not only improve the utilization rate of marginal land and alleviate the competition between forage and cereal crops for arable land but will also increase the yield of high-quality domestic forage. In this study, we conducted transcriptomic analysis on the saline-alkali-tolerant alfalfa cultivar NQ-1 and compared its metabolite accumulation levels with saline-alkali-sensitive cultivars. The results showed that under saline-alkali stress, the photosynthesis and some secondary metabolic pathways in NQ-1 were activated, such as α-Linolenic acid metabolism, Phenylpropanoid and Flavonoid biosynthesis, and Photosynthesis-related pathways, providing substances and energy for enhancing NQ-1 stress tolerance. Furthermore, some specific flavonoids were detected that may contribute to the saline-alkali tolerance of NQ-1. In addition, transcription factors that may regulate flavonoid biosynthesis in NQ-1 under saline-alkali stress were also identified. This study deepens the understanding of the resistance mechanism of saline-alkali-tolerant cultivars of alfalfa and provides valuable information for molecular design breeding strategies for stress-resistant alfalfa.

Soil salinization–alkalization is a critical abiotic constraint on global agriculture, threatening agroecosystem sustainability. Leymus chinensis, a high–quality perennial forage with strong stress resilience, is an ideal model for studying saline–alkali tolerance in graminaceous crops. We integrated physiological, transcriptomic, and metabolomic profiling to dissect its responses under moderate vs. severe carbonate stress, mimicking natural saline–alkali soils rather than single salt stress treatments. Multi–omics analysis revealed drastic reprogramming of energy metabolism, carbohydrate homeostasis, water transport, and secondary metabolism. Our novel finding reveals that L. chinensis uses stress–severity–dependent mechanisms, with flavonoid biosynthesis as a central “regulatory hub”: moderate saline–alkali stress acts as a stimulus for “Adaptive Activation” (energy + antioxidants), promoting growth, while severe stress exceeds tolerance thresholds, causing “systemic imbalance” (oxidative damage + metabolic disruption) and growth retardation. Via WGCNA and metabolome–transcriptome modeling, 22 transcription factors linked to key flavonoid metabolites were identified, functioning as molecular switches for stress tolerance. Our integrated approach provides novel insights into L. chinensis’ tolerance networks, and the flavonoid biosynthesis pathways and regulatory genes offer targets for precision molecular breeding to enhance forage stress resistance and mitigate yield losses from salinization–alkalization.

Aluminum toxicity severely inhibits root elongation and nutrient uptake, causing global agricultural yield losses. Dissolved Al³⁺ are accumulating in plants and subsequently entering food chains via crops and forage plants. Chronic dietary exposure to Al³⁺ poses a risk to human health. In this study, Pseudomonas sp. strain ADAl3–4, isolated from plant rhizosphere soil, significantly enhanced plant development and biomass. Phenotypic validation using Arabidopsis mutants showed that strain ADAl3–4 regulates plant growth and development under aluminum stress by reprogramming the cell cycle, regulating auxin and ion homeostasis, and enhancing the root absorption of Al³⁺ from the soil. Transcriptomic and biochemical analyses showed that strain ADAl3–4 promotes plant growth via regulating signal transduction, phytohormone biosynthesis, flavonoid biosynthesis, and antioxidant capacity, etc., under aluminum stress. Our findings indicate that Pseudomonas sp. strain ADAl3–4 enhances plant development and stress resilience under Al³⁺ toxicity through a coordinated multi-dimensional regulatory network. Furthermore, strain ADAl3–4 promoted the root absorption of aluminum rather than the transportation of Al to the aerial part, endowing it with application prospects.

Alpine dwarf pine populations are dwelling in a climate-sensitive habitat, where detection of the carbon (C) cycle is still valued for sustainability. Foliar and soil parameters are key factors that combine to jointly affect aboveground C storage in alpine ecosystems, but how they generate combined contributions to aboveground C in alp dwellers still needs more research. In this study, Pinus pumila, a typical alp dwarf pine species in a canyon of the Great Khingan Mountain, was focused on. Their natural populations were investigated for individual growth and needle and soil parameters in plots across six categorized elevations from 800 m to 1200 m. Aboveground C storage was estimated by three allometric models which were all found to increase against increases in elevation. Along the increasing elevational gradient, needle concentrations of nitrogen (N) and phosphorus (P) both showed decreasing trends, but activities of N and P assimilation enzymes and chlorophyl contents, as well as the soil contents of ammonium N and organic matter, all showed increasing trends. Multiple linear regression models indicated that elevation (parameter estimate, PE: +0.01), needle P (PE: +0.66) and chlorophyl contents (PE: +0.60) made jointly positive contributions to estimated C storage while soil pH had a negative contribution (PE: −1.80). For the purpose of sustainable C fixation by alp P. pumila populations, strategies should be considered to increase P availability and control high soil pH. Our results fill the gap about C storage and driving forces in alpine ecosystems, and their applications are not limited to being referenced by other alpine plants.

Jasmonic acid (JA) signaling plays a pivotal role in plant stress response, with Jasmonate ZIM-domain (JAZ) proteins acting as key transcriptional repressors. Quinoa (Chenopodium quinoa Willd.) is highly stress-tolerant, but its JAZ gene family remains poorly characterized. In this study, we identified 11 CqJAZ genes in the quinoa genome and systematically analyzed their phylogenetic relationships, gene structures, conserved motifs, and cis-acting elements in their promoters. Expression profiling revealed distinct response patterns of CqJAZ genes to salt, drought, and saline-alkali stresses, among which CqJAZ1 was significantly down-regulated under all three conditions. Subcellular localization analysis indicated that CqJAZ1 is localized to the nucleus. Ectopic overexpression of CqJAZ1 in Arabidopsis thaliana inhibited root growth and reduced survival rates under salt, saline-alkali, and osmotic stresses. Physiologically, CqJAZ1-overexpressing lines had elevated malondialdehyde (MDA), decreased superoxide dismutase (SOD) and peroxidase (POD) activities, and reduced endogenous JA accumulation under stress conditions. Furthermore, they showed reduced methyl jasmonate (MeJA) sensitivity. Collectively, CqJAZ1 negatively regulates quinoa stress tolerance by modulating JA homeostasis and compromising antioxidant defense capacity, shedding light on quinoa’s JA signaling and stress-resistance mechanisms.

Plant SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) constitute a large superfamily and play pivotal roles in diverse biological processes and responses to various abiotic stresses. Quinoa (Chenopodium quinoa wild.) is a nutritionally superior crop endowed with robust tolerance to environmental stresses. In this study, we identified 88 CqSNARE genes in quinoa, which are unevenly distributed across 18 chromosomes and classified into 23 subfamilies. We systematically analyzed their physicochemical properties, phylogenetic relationships, gene and protein structures, and cis-acting elements. Furthermore, transcriptome analysis of quinoa leaves under saline–alkaline stress revealed that CqSNAP30a was the most significantly upregulated. This gene is predominantly expressed in leaves and localized on the plasma membrane. Constitutive expression of CqSNAP30a enhanced plant stress resistance by regulating ion homeostasis and antioxidant capacity. Our findings provide valuable insights into the SNARE genes of stress-tolerant crops and lays a theoretical foundation for the genetic improvement of stress resilience.