Ultraviolet-B radiation (UV-B) has a dual effect on plants, enhancing growth under low doses but causing oxidative damage, irregular photosynthesis, and abnormal growth at high doses, negatively impacting lignin biosynthesis, stem strength, and yield. Abscisic acid (ABA) mitigates these effects by promoting photosynthesis, regulating growth, and maintaining hormonal flux. Limited attention has been given to the role of ABA in stress mitigation and yield improvement for high-altitude crops like qingke (highland barley; Hordeum vulgare L. var. nudum). This study investigates the effects of UV-B radiation and ABA on the physiological, biochemical, transcriptomic, metabolomic, and hormonal responses of qingke. Low-dose UV-B (LUVB; 5-6 kJ m-2 d-1) increased plant height by 51.3% but reduced stem diameter by 31.6%. ABA supplementation (70 μM) under UV-B (ABA-UVB) moderated height (20.7% increase) and improved stem diameter by 8.1%. The ABA under UV-B increased tillers (57.1%), spikes (66.5%), and yield (26.2%). At the molecular level, this treatment upregulated lignin biosynthesis genes transcripts (PAL, 4CL, CAD, POD) and enhanced enzymatic activities by 69.0% to 150.1%. Metabolomic analysis revealed elevated lignin precursors, including p-coumaryl alcohol and sinapyl alcohol. Hormonal profiling showed ABA restored Indole-3-acetic acid (IAA) and gibberellic acid (GA) levels, elevated trans-zeatin (tZ), and maintained hormonal balance. Nutrient analysis revealed higher leaf magnesium (Mg) by 28% and calcium (Ca) by 40%, along with increased root manganese (Mn) and copper (Cu) levels under UVB-ABA, which enhanced stress adaptation. These physiological, transcriptomic, and metabolomic changes collectively strengthened stems, improved lodging resistance, and enhanced yield suggesting the potential of ABA for mitigating UV-B stress in high-altitude crops.

Low temperature is a major abiotic stress that affects maize across its entire growth cycle, with the germination stage being particularly sensitive. To investigate the genetic basis of early-stage cold tolerance, we used quantitative trait locus mapping and identified ZmbHLH30 as a candidate gene regulating maize responses to low temperature. The ZmbHLH30 protein is localized in the cytoplasm of maize protoplasts, and ZmbHLH30 promoter drives β-glucuronidase (GUS) expression in Arabidopsis thaliana leaves. The promoter region of ZmbHLH30 contains multiple environmental stress-responsive elements, including motifs associated with cold and auxin responses. Overexpression of ZmbHLH30 significantly enhanced cold tolerance at the germination, bud, and seedling stages, with the strongest effect observed during germination, where the cold-tolerance D-value increased by 0.366 relative to the control. In contrast, CRISPR/Cas9 knockout lines showed a 0.399 decrease in D-value. Under cold stress, ZmbHLH30 expression was markedly induced in overexpression lines but suppressed in knockout lines. Integrated transcriptomic and metabolomic analyses further identified ZmbHLH30 as a key regulator of cold tolerance in maize.

The Qinghai-Xizang Plateau has abundant sunlight resources. Making rational use of this advantage can effectively increase the forage yield and nutrient accumulation of mixed grassland sown with gramineous and leguminous plants. External fertilization is a key measure to further enhance the productivity and quality of the mixed grassland. This study focused on the Avena sativa+Pisum sativum mixed sowing system and set up four treatment groups: single application of nitrogen fertilizer (A1), single application of phosphorus fertilizer (A2), nitrogen and phosphorus combined application (A3), and no fertilization control (CK). The study evaluated the effects of different fertilization treatments on the spectral indices and leaf morphology of the oat-pea mixed sowing leaves and their impact on forage quality. The results showed that under the nitrogen and phosphorus combined application treatment, the total chlorophyll content of oat plants was 15.14% higher than that of the CK; the soil-plant analysis development value was 26.44% higher than that of the CK, 17.05% higher than A1, and 26.85% higher than A2. In terms of leaf morphology, the nitrogen and phosphorus combined application significantly increased leaf area, while single application of nitrogen fertilizer made leaf length, leaf width, and perimeter higher than that of the CK. In terms of nutritional quality, the nitrogen and phosphorus combined application significantly increased total phosphorus, total nitrogen, crude protein, soluble sugar, and total carbon content, and simultaneously reduced neutral detergent fiber and acid detergent fiber by 7.78% and 25.25%, respectively, compared to the CK. In summary, the combined application of nitrogen and phosphorus significantly affected the spectral indices, morphology, and plant nutrient indicators of the leaves. This fertilization strategy and mixed sowing combination can be applied in the experimental area to further enhance the yield and quality of artificial grassland.

The alpine grassline represents the uppermost elevation of alpine grasslands, where low temperature is generally considered to be the primary constraint. However, the key drivers shaping alpine grassline formation remain poorly understood, limiting our ability to predict their response to climate warming. Here, we conducted a 4-year transplant experiment across four elevations spaced at 50-m intervals above the worldwide highest alpine grassline (5200 m a.s.l.) on the central Tibetan Plateau. At each transplant elevation, both open-top chamber (OTC) warming and control plots were set. Cover, height, aboveground biomass (AGB) of the grassline dominant species, Kobresia pygmaea, and community diversity indices were recorded for each elevation and treatment. Our data showed that K. pygmaea cover, height, and AGB declined in the control plots transplanted upward beyond the grassline. However, K. pygmaea showed short-term persistence at the highest transplanted elevation (5350 m) and maintained a cover greater than 50%, suggesting that soil conditions, rather than climate alone, are a key factor limiting its distribution above the alpine grassline. OTC warming reduced K. pygmaea cover while increasing plant height across all transplanted elevations, and these contrasting responses were associated with no significant increase in AGB relative to the control plots. At the community scale, upward transplantation led to a general decline in plant community diversity, and warming treatments further reduced plant diversity. These findings reveal that both higher-elevation climatic stress and limited soil development are likely to constrain plant growth and diversity beyond the grassline under warming, advancing our understanding of the mechanisms underlying alpine grassline distribution and its response to climate warming.

Pseudomonas sihuiensis F3 was isolated from a lignin-degrading bacterial consortium. It also exhibits excellent lignin-degradation capability. However, the mechanism underlying its high efficiency in lignin degradation remains unclear. This study investigated the functional genes associated with lignin degradation in Pseudomonas sihuiensis F3. Based on whole-genome analysis, the F3 genome exhibits a total size of 5.16 Mb, comprising 4,764 genes with an average GC content of 62.75%. Transcriptomic analysis identified key lignin degradation-related genes. Based on these results, the lignin metabolic pathways of strain F3 were predicted to include the biphenyl, ferulic acid, methyl gallate, protocatechuic acid, and vanillic acid pathways. The results of this experiment provide a theoretical basis for further research into the lignin-degrading properties of strain F3.

Abstract Background Heavy metal pollution, a pervasive and persistent environmental stressor often linked to industrial and agricultural activities, interacts with intra- and interspecific competition as key factors influencing the invasion of exotic plants. Alternanthera philoxeroides and Trifolium repens exhibit distinct allocation strategies to mitigate resource competition under cadmium (Cd) pollution, yet their differential resistance to Cd remains underexplored. Results In this study, a greenhouse experiment was conducted to investigate the effects of Cd contamination and competitive interactions on the stress resistance index (SRI) and adaptive strategies of both species. The results indicated that T. repens exhibited higher SRI under stronger interspecific competition, demonstrating clear density dependence. T. repens primarily enhanced its competitiveness by increasing photosynthesis capacity, though its root system structure contributed more substantially to SRI. In contrast, A. philoxeroides increased SRI by forming shorter and thicker root system. Conclusion Overall, the root utilization strategy of A. philoxeroides showed greater advantages than that of T. repens. Under intraspecific competition, A. philoxeroides improved competitiveness mainly through increased root complexity and optimized photosynthetic efficiency via non-stomatal regulation in light competition. The invasiveness of A. philoxeroides can be attributed to the ability to synergistically combine root development and photosynthesis to enhance its stress resistance. This study provides a broader perspective on invasion mechanisms in natural ecosystems and offers a solid theoretical basis for understanding stress tolerance and environmental management of A. philoxeroides.

Abstract The Tibetan Plateau is the highest and largest plateau in the world, which is also the most important ecological security barrier in China, with its vegetation serving as a critical foundation for this ecological function. The vegetation on the Tibetan Plateau has undergone drastic changes duo to climate change, human disturbances, and natural succession. A large-scale vegetation map is urgently needed for elucidating the distribution patterns of vegetation types. Based on 211 538 vegetation samples and 322 vertical vegetation zonation spectra, hierarchical and regional mapping strategies were employed to produce the vegetation map of the Tibetan Plateau (1:500 000) at the alliance level. This vegetation map accurately depicts the distribution patterns of 561 vegetation types (including 523 alliances, 32 alliance groups, 2 vegetation subformations, and 4 vegetation formations) and 12 non-vegetated types, and 61 alliances are recorded for the first time on the Tibetan Plateau. The overall accuracy and kappa coefficient are 66.76% and 0.66 at the alliance level. Compared with the vegetation of China (1:1000 000), the number of mapping units of the current vegetation map has increased from 327 to 573. The number of mapping patches has grown from 15 082 to 117 325, with the average area of patches decreasing from 171.13 to 22.00 km2. Compared with the vegetation map of China, the current map shows that forests, shrublands, grasslands, deserts, alpine sparse vegetation and agricultural vegetation have changed by 23.87%, 66.40%, 21.36%, 48.05%, 41.48%, 64.87%, respectively. This vegetation map can reflect the current vegetation distribution patterns on the Tibetan Plateau more precisely, which could provide stronger foundational supports for ecosystem management, biodiversity conservation, and national strategic decisions.

The global nitrogen (N) and phosphorus (P) content of the soil exhibits distinct latitudinal variations, yet their variation along elevational gradients in alpine forest ecosystems remains poorly understood. Based on 28 sampling sites spanning an elevational range of 769-3,767 m in alpine forests on the southeastern Tibetan Plateau, we analyzed variations in soil N and P contents and their stoichiometric ratios, and explored the key driving factors. The results showed that soil N and P exhibited asynchronous nonlinear changes along the elevational gradient. Soil N increases with increasing altitude, reaching a peak at approximately 2,800 m above sea level, and then decreases as altitude continues to rise. In contrast, soil TP and AP exhibited an opposite nonlinear pattern. This N-P decoupling was reflected in the unimodal pattern of the soil N: P ratio, which reached a maximum value of 11.8 ± 1.86 at approximately 2,800 m. Elevated soil temperature resulted in a non-linear decrease in the N: P ratio. The collection of literature on a global scale also indicates that the N: P ratio of temperate evergreen coniferous forests is significantly higher than that of functional types of tropical and alpine plants. The asynchronous elevational patterns of soil N and P observed in this study provide empirical references for understanding nutrient cycling in montane ecosystems and for assessing potential soil nutrient dynamics under future climate change.

The 26 kDa α-globulin, a minor component of rice seed storage proteins (SSPs), is encoded by the single-copy gene α-globulin 1 (Glb1), which is specifically expressed in the endosperm. However, the specific effects of altered α-globulin content on SSP composition and grain quality remains poorly understood. In this study, we demonstrated that modulation of α-globulin levels significantly enhances both total protein content and accumulation of the essential amino acid lysine in Glb1 knockout mutants and overexpression lines. Notably, specific alterations in SSP composition were observed exclusively in Glb1 mutants, with no such changes detected in overexpression lines. Glb1 knockout mutants produced abnormal protein bodies, including small-sized protein body I and center-cracked protein body II. Furthermore, increased proglutelin accumulation in Glb1 mutants triggered endoplasmic reticulum stress, resulting in a higher chalky grain rate. However, the altered α-globulin content had minimal effects on grain weight and starch properties compared with the wild type. This study elucidates the role of α-globulin accumulation in SSP reprogramming and provides a potential strategy for enhancing rice endosperm lysine content through the regulation of Glb1 biosynthesis.

Earlymaturity and lowear position traits are important selective traits in maize breeding procedures, especially in northern China. To construct a genomic prediction model for selecting early-maturity and low-ear-position hybrids adapted to different environments, 34elite inbred lines were selected to produce 285 single-cross hybrids using a partial diallel cross design. These inbred lines constituted a mini-core collection of Chinese maize germplasm, comprising 18 inbred lines from the Stiff Stalk heterotic group and 16 inbred lines from the Non-Stiff Stalk heterotic group. The parental inbred lines were genotyped by sequencing, and the 285 hybrids were phenotyped for early-maturity and low-ear-position-related traits at seven locations in China. The results revealed significant variations in early maturity and low ear position traits among seven locations. These traits were highly correlated across locations, with high heritability ranging from 0.89 to 0.94, indicating that genetic factors primarily govern early maturity and ear position. The population structure showed that the hybrids were mainly composed of four subgroups. Among them, the Reid × Iodent subgroup exhibited the shortest growth period and the lowest ear position across the seven locations and showed relatively high genetic diversity. Correspondingly, the low general combining abilities of the inbred lines in both subgroups across the locations were also identified. The genomic prediction accuracy of these agronomic traits ranged from 0.26 to 0.89. Accuracy across seven locations ranged from 0.37 to 0.89. We also found that effective genomic prediction models can be set and developed using a training set comprising less than 16

Global food production depends largely on cereal crops such as rice (Oryza sativa L.), maize (Zea mays L.), wheat (Triticum spp.), and sorghum (Sorghum bicolor). Plant pathogens, including fungi, bacteria, and viruses—exacerbate global food insecurity by lowering yields and posing risks to both human and animal health. To defend against these threats, plants have developed complex immune systems capable of recognizing and responding to invading organisms. Pathogens, however, have evolved diverse strategies to bypass or suppress host defenses. In this review, we outline the major fungal, bacterial, and viral diseases of cereal crops, describe their distribution and co-evolutionary patterns, and highlight recent advances in understanding jasmonic acid (JA)–mediated defense mechanisms.

Rhinopithecus bieti is a rare and endangered species unique to China, and habitat ecological environment quality would affect its population persistence. Taking the Markam Yunnan Snub-nosed Monkey National Nature Reserve in Tibet as the study area, we calculated a remote sensing ecological index (RSEI) based on Landsat imagery from 2000 to 2024. We further analyzed the spatiotemporal variations and driving factors of ecological environmental quality using trend analysis methods, including the Theil-Sen median estimator, in combination with XGBoost and SHAP models. From 2000 to 2024, the RSEI of the study area exhibited an overall fluctuating upward trend and peaked in 2024. Spatially, it showed a distribution pattern characterized by stable core areas and degraded marginal areas. Areas with significant RSEI improvement were mainly distributed in the central-eastern part of the reserve and some high-altitude regions in the west area, while markedly degraded areas were concentrated along the western marginal zone. About 42% of the reserve area was predicted to face potential ecological degradation risks in the future. Land use was the dominant factor influencing RSEI variation, and its interaction effects with elevation, mean annual temperature, and snow cover ratio on RSEI were significant. The impacts of all driving factors on RSEI exhibited pronounced nonlinear characteristics. This study would provide a scientific basis for assessing the ecological environmental quality of habitats of rare and endangered species and offer important references for ecological monitoring and sustainable development of protected areas located in high-altitude regions.

Understanding adaptive evolution has long fascinated evolutionary biologists. Adaptive phenotypic divergence is often driven by modifications to protein-coding sequences. The Rhinolophus macrotis group exhibits relatively lower echolocation frequencies relative to body size compared with other rhinolophids, implying distinct evolutionary trajectories. Transcriptomes bridge genotypes and phenotypes. Here, we sequenced brain, liver and cochlea transcriptomes from one individual per species representing five taxa of the macrotis group. We performed comparative transcriptomic analyses and detected signals of positive selection. Seven hearing-related genes (CRYM, FOXM1, MAP6, PYCARD, SLC35A2, WRB and SPRY2) were under positive selection. Unexpectedly, we also identified five vision-associated positively selected genes (ARRDC3, LZTFL1, RAB8A, IGFBPL1 and TRNT1) in taxa with relatively lower echolocation frequencies within the macrotis group, indicating selection on sensory genes. Furthermore, candidate positively selected genes were significantly enriched in metabolism-related GO terms such as catalytic and oxidoreductase activity. Our study offers valuable transcriptomic resources for unraveling adaptive genetic mechanisms in horseshoe bats.

Current cereals face unassailable yield trade-offs under combined water deficit (D) and ultraviolet-B (UV-B) stress. Using integrated omics in qingke barley subjected to D, UV-B (low: LUVB; high: HUVB), and abscisic acid (ABA), we show that ternary DUVB-ABA cotreatment elevates ABA and GA, enabling concurrent stress resilience and growth recovery. This treatment activated NCED3 genes for ABA biosynthesis and KAO for GA biosynthesis. ABA with UV-B preserved membrane fluidity by upregulating fatty acid desaturases (FADs) and suppressing lipoxygenases (LOX); LUVB-ABA reduced oxidative damage by 81.8%. Crucially, conventional trade-offs were eliminated: D-LUVB-ABA improved 1000-seed weight by 10.3% above controls, while D-HUVB-ABA elevated grain sugar and protein content significantly. Potassium accumulation in the stem (>51%) and spectral priming (LUVB for stress memory; HUVB for growth reactivation) supported these effects. Findings show ABA-UVB interaction reprograms stress cues into productivity triggers, identifying spectral hormone discrimination and stem nutrient buffering as key adaptations for climate-resilient cereals.

Alpine grasslands are highly sensitive to environmental changes, with leaf longevity crucially modulating carbon cycling. Addressing uncertainties in long-term leaf longevity dynamics, driving mechanisms and its interplay with net primary productivity (NPP), we analyzed the spatiotemporal changes in leaf longevity and NPP of the Three-Rivers-Source Region (TRSR) from 2003 to 2022 using multi-source remote sensing data. Key drivers of leaf longevity were identified using XGBoost-SHAP algorithm and lasso regression, while a causality-based model projected future trajectories. Results showed that over 81 % of the study area exhibited a significant leaf longevity extension (9.32 days decade-1 ), mainly due to delayed leaf senescence date. Concurrently, regional NPP increases were dominated by summer gains. There was a non-linear positive correlation between leaf longevity and NPP, confirming that longer leaf longevity enhanced carbon uptake by prolonging photosynthesis. However, this marginal gain declined once leaf longevity surpassed the ecological threshold (about 150 days), indicating that after summer vegetation activity peaks, relying solely on extending the growing season does not lead to substantial net carbon gains, and the carbon sink becomes saturated. Temperature consistently drove leaf longevity variation, while enhanced solar radiation exerted increasing influence, highlighting the greater importance of photothermal resources for foliar phenology. Projections suggested continued leaf longevity extension under SSP245 and SSP585 climate scenarios, with short-term NPP increasing but long-term stagnating or declining. These findings emphasize that alpine grassland management should prioritize ecosystem sustainability and adaptive resilience over maximizing leaf longevity, especially under extreme climate stresses, offering key insights for carbon sequestration optimization and restoration strategies in global alpine ecosystems.

Highland barley often encounters simultaneous drought conditions and ultraviolet-B (UV-B) radiation exposure. Although antioxidant responses are well studied, the interaction between nutrient absorption and hormonal regulation under these combined stresses is less understood. This research explores the physiological and molecular processes underlying these cross-stress interactions. This study examined the effects of various conditions on qingke, including MD (moderate drought; 50

ABSTRACT Question Facilitation and competition often co‐occur in plant communities, jointly shaping species composition and mediating ecosystem responses to environmental changes. However, whether they vary in different directions with increasing environmental stress remains unclear, because most studies quantify only net effects. Location A semiarid system in southeast Spain dominated by the leguminous shrub Retama sphaerocarpa , where environmental stress increases from the canopy center to the canopy edge and is highest in open gaps between shrubs. Methods At the beginning of the growing season (December 2021), we applied a chess‐like design template with 2 × 2 cm cells to 50 × 50 cm plots and removed all visible understory herbaceous plants from alternate cells, achieving approximately 50% removal of understory plants. Plots were located at the Retama canopy center, at the canopy edge, and in open gaps between shrubs. Plant biomass was harvested at the end of the growing season (June 2022) on both removal and control plots. Facilitation of Retama on understory species was quantified by comparing plant biomass in canopy control and gap control plots, and competition among beneficiary species was quantified from the plant biomass response to neighbor removal within each canopy position, using the relative interaction index (RII). Soil temperature and moisture were recorded in both control and removal plots during the experiment period. Results Neighbor removal increased soil temperature variability and slightly reduced soil moisture relative to control plots. Biomass of understory species was highest at the canopy center and decreased toward the canopy edge and in gaps in both control and removal plots. However, biomass in removal plots was greater than half that in control plots, reflecting competition effects. Facilitation by shrubs was slightly stronger at the canopy center than at the edge. In contrast, competition among understory species increased from the canopy center to the canopy edge and was strongest in gaps. Conclusions Co‐occurring facilitation and competition responded independently and in opposite directions along the environmental gradient in a nurse shrub system, with facilitation decreasing and competition increasing from canopy center to gaps.

Precipitation patterns in the Himalayas vary in complex ways with elevation but remain poorly understood due to limited in situ data. In this study, we present observations from two rain-gauge networks spanning different elevations established in the Yarlung Tsangpo Grand Canyon and the Khumbu Valley. Using these ground-based data, we provide the first comparative investigation of summer precipitation variation along elevation gradients in the Central and Eastern Himalayas. In both regions, precipitation increases with elevation up to a peak and then decreases between 1,500 and 4,300 m above sea level. A marked precipitation maximum occurs near 2,500 m above sea level, largely induced by frequent heavy precipitation events (>= 1 mm hr-1). The diurnal cycle of mean precipitation generally displays a consistent unimodal pattern, with a daytime minimum and a nighttime maximum. However, the diurnal variation exhibits distinct afternoon differences with elevation in the Central and Eastern Himalayas: an afternoon secondary peak in precipitation is discernible at low- and mid-elevation sites in the Central Himalaya, which is absent in the Eastern Himalaya. The former is primarily associated with ridge convection triggered by afternoon upslope flow, whereas the latter is suppressed by the descending branch of local mountain circulation driven by convection at high elevations.

Pre-harvest sprouting (PHS), caused by weak seed dormancy and environmental stimuli, leads to significant losses in both crop yield and grain quality. Breeding crop cultivars with enhanced PHS resistance represents a promising strategy to address this challenge. However, limited useful genetic resources has hindered the progress in rice molecular breeding. Through screening of a rice mutant library, we identify the ethylene response factor115 (erf115) mutant, which exhibits enhanced PHS resistance. Genetic analysis reveals that ERF115 functions as a negative regulator of seed dormancy. Mechanistic assays show that the E3 ubiquitin-protein ligase Grain Width 2 (GW2) interacts with and ubiquitinates ERF115, thereby promoting its proteasomal degradation. Accordingly, gw2 mutants display increased PHS susceptibility. ERF115 also interacts with the transcription factor SLR1-like 2 (SLRL2) and represses its transcriptional activation activity, consequently reducing the expression of the dormancy gene Mother of FT and TFL1 like 2 (MFT2). Haplotype analysis identifies three major ERF115 haplotypes (HapI-HapIII), among which ERF115Hapl represents an elite allele associated with reduced PHS. Collectively, our findings reveal a GW2-ERF115-SLRL2 regulatory module that integrates ubiquitin-mediated regulation and hormone signaling to fine-tune rice seed dormancy, providing valuable genetic resources for breeding PHS-resistant rice varieties.