Search Results (554)

Fibrillins (FBNs) are conserved plastid-associated proteins implicated in plant development and abiotic stress responses; however, their roles in maize remain unclear. In this study, through a genome-wide bioinformatic analysis, we identified 14 ZmFBN genes in the maize genome and characterized their phylogeny, chromosomal distribution, gene structure, conserved motifs, and promoter cis-elements. ZmFBN members were grouped into several subfamilies that all retain a conserved PAP_fibrillin domain, whereas the variation in exon–intron organization, motif composition, and regulatory elements suggests functional diversification. Expression profiling revealed pronounced tissue-preferential patterns, with many genes highly expressed in leaves and reproductive tissues, and distinct responses to drought, salt, heat, and cold stresses. qRT-PCR assays showed that ZmFBN8 and ZmFBN9 are strongly induced by both salt and PEG-simulated drought, ZmFBN2 and ZmFBN5 are predominantly drought-responsive, and ZmFBN11 is mainly activated by salt. Genome-wide association analysis further detected significant loci near ZmFBN1 and ZmFBN4, whose allelic variants are associated with the survival rate under drought and with key agronomic traits, including the tassel branch number, flowering time, ear diameter, and kernel length. These results demonstrate that ZmFBN genes make diversified contributions to maize growth, development, and stress adaptation and highlight several members as promising targets for functional studies and the molecular breeding of stress-tolerant maize. Moreover, selection pressure analysis indicated ZmFBN7 experienced relaxed purifying selection, and ZmFBN12 underwent positive selection, which drives the functional diversification of the ZmFBN family during maize evolution. Full article

Background/Objectives: This study aims to reveal the physiological and molecular regulatory mechanisms of the genuine medicinal herb I. suzhouensis K. F. Zhai, Z. B. Han & S. B. Zhou (Wangzaozi) of Anhui province in response to drought stress, and clarify the regulatory patterns of drought adversity on the accumulation of its medicinal active ingredients. Methods: Mild natural drought treatment was applied to I. suzhouensis. Combined with Illumina high-throughput transcriptome sequencing and HPLC-MS/MS targeted metabolomics detection, this study jointly deciphered the dynamic changes in gene expression and metabolite accumulation of I. suzhouensis under drought. Key drought-responsive metabolic pathways, core regulatory genes and marker metabolites were screened. Results: A total of 56,823 high-quality unigenes were obtained via transcriptome sequencing, among which 23,580 differentially expressed genes (DEGs) were identified. Functional enrichment analysis revealed that DEGs were predominantly enriched in pathways, including plant hormone signal transduction, phenylpropanoid biosynthesis, flavonoid biosynthesis and photosynthesis. A total of 4171 metabolites were qualitatively and quantitatively characterized via metabolomics, and 1632 differentially expressed metabolites (DEMs) were screened, mainly enriched in phenylpropanoid biosynthesis, tyrosine metabolism, flavone and flavonol biosynthesis pathways. Physiological measurements of antioxidant indices demonstrated that the activities of SOD and POD increased by approximately 2-fold, while PAL activity rose by 1.55-fold, and chlorophyll content decreased significantly. Multi-omics joint analysis indicated that mild drought stress modulates the expression of genes involved in phenylpropanoid, flavonoid and diterpenoid biosynthetic pathways, alters antioxidant enzyme activities, and coordinately regulates the formation of drought tolerance and the accumulation of bioactive compounds in I. suzhouensis. Conclusions: This study systematically elucidates the drought response mechanism of I. suzhouensis cultivated in northern Anhui province. It provides theoretical evidence and candidate core responsive gene resources for standardized cultivation of I. suzhouensis and precise regulation of medicinal quality in drought-prone production areas. Full article

Hydroclimatic evidence is often carried too directly from global-scale attribution studies into local water-resources decisions, despite important differences among variables, methods, and spatial scales. This critical narrative review examines how climate variability, statistical trends, detection, attribution, non-stationarity, and risk should be distinguished when interpreting changes in precipitation, drought, streamflow, floods, groundwater, and water availability. The review compares global assessments, Mediterranean studies, and selected local examples to clarify what each line of evidence can—and cannot—support in adaptation planning. Human influence on global warming is unequivocal, and increases in atmospheric evaporative demand are well supported across many regions; anthropogenic influence has also been detected in several large-scale water-cycle responses. Historical changes in precipitation, river flooding, groundwater, and local drought remain spatially heterogeneous because internal variability interacts with circulation, storage, landscape properties, abstraction, infrastructure, and demand. Statistically significant trends do not by themselves establish hydrological importance or causation, while non-significant local trends do not imply an absence of operational risk. On this basis, the review proposes a scale-aware way of matching hydroclimatic evidence with system vulnerability and the degree of commitment involved in adaptation. Low-regret and adjustable measures can address current vulnerabilities under uncertainty, whereas costly, long-lived, or difficult-to-reverse interventions require stronger local evidence and stress testing across plausible futures. Full article

Urban green spaces (UGSs) are vital for enhancing a city’s resilience and livability; however, their functionality is increasingly jeopardized by drought, particularly in water-scarce regions. This study evaluates drought impact on UGSs in Metropolitan Adelaide, Australia, a representative semi-arid urban system, using satellite-derived Normalized Difference Vegetation Index (NDVI) time-series data spanning 2000–2020. Vegetation dynamics were analyzed through Seasonal-Trend decomposition using Loess (STL), standardized anomaly assessment, lagged Pearson correlation, Ordinary Least Squares (OLS) regression, and Mann–Kendall trend analysis. To isolate climatically sensitive signals, 29 urban lawn patches were examined separately from mixed urban canopy, given their shallow root systems and direct dependence on surface moisture. NDVI declined by approximately 0.09 units during the Millennium Drought (2001–2009), with summer greenness deficits reaching 24% below the 20-year benchmark. Temperature was the dominant driver of lawn NDVI variability (r = −0.863, R² = 74.5%), substantially exceeding the effect of rainfall (r = 0.156, R² = 2.4%). El Niño–Southern Oscillation (ENSO) cycles modulated vegetation responses, with La Niña years supporting recovery and El Niño years amplifying decline. Post-drought recovery remained incomplete, with NDVI deficits of 8–20% persisting through 2020; full recovery was observed only in 2017, coinciding with the highest recorded summer rainfall. No significant directional trend was detected over the full study period (Mann–Kendall τ = 0.005, p = 0.908). These findings demonstrate that heat, rather than water limitation alone, is the primary driver of vegetation stress in urban systems, highlighting the benefits of integrated management strategies that address both warming and moisture deficits to sustain urban green infrastructure under future climate conditions. We introduce the concept of “urban greenery drought,” referring to a form of vegetation stress in managed urban landscapes where greenness is reduced primarily by elevated temperature and atmospheric demand despite water availability. Full article

Climate change has increased the frequency of hotter droughts and forest decline processes, highlighting the need for monitoring methodologies capable of detecting loss of vigor on the individual-tree scale. Pinus pseudostrobus is an economically important species in the temperate forests of the indigenous community of Nuevo San Juan Parangaricutiro, Michoacán. The aim of this study was to evaluate the elevational and thermal factors associated with the spatial and temporal variability of P. pseudostrobus vigor by integrating multispectral, LiDAR, and land surface temperature (LST) data. Five multispectral flights were conducted using unmanned aerial vehicles (UAVs) between June 2023 and June 2024, along with one LiDAR flight in April 2024, across an elevational gradient ranging from 2150 to 2920 m. High-resolution orthomosaics, NDVI and LCI indices, a canopy height model, and an object-based classification using Random Forest were generated. LST was obtained from Landsat 8–9 imagery in Google Earth Engine using the Statistical Mono-Window algorithm. Spectral, thermal, and elevation values were extracted at the individual-tree level. The classification achieved an overall accuracy of 69.6% and enabled the identification of 28,585 P. pseudostrobus individuals. NDVI and LCI varied significantly among periods, elevations, and their interaction. The lowest values of vigor were recorded in lower elevation areas, particularly in June 2023, April 2024, and June 2024. In addition, both indices decreased as LST increased, showing strong negative relationships for NDVI (R² = 0.96) and LCI (R² = 0.86). Individuals located at the lower elevational limit showed greater vulnerability to thermal stress. Full article

The frequency and magnitude of droughts are increasing concurrently with atmospheric CO₂ concentration, with profound consequences for plant carbon assimilation. However, the interactions and the underlying physiological mechanism are still not fully understood. To fill the knowledge gap, we exposed Chinese fir (Cunninghamia lanceolata) saplings to two CO₂ concentrations (400 and 800 ppm, representing ambient and elevated CO₂) and two soil water regimes (70% and 40% field capacity; well-watered and drought-stressed conditions) in a factorial design. Net photosynthetic rate (A_n), chlorophyll fluorescence, photosynthetic pigments, oxidative stress indicators, and antioxidant enzyme activities were measured four times over a 45-day treatment period. Under well-watered conditions, elevated CO₂ significantly increased A_n by 61.5%. However, drought stress substantially reduced A_n by 75.0% under ambient CO₂ and by 75.6% under elevated CO₂, whereas no statistically significant CO₂-induced increase was detected under drought conditions. Furthermore, drought stress caused marked reductions in stomatal conductance, transpiration, chlorophyll content, and photosystem II (PSII)-related parameters, together with increased malondialdehyde, proline, and antioxidant enzyme activities. Variance partitioning analysis suggested that stomatal regulation (SR), photosynthetic capacity (PC), and stress response (STR) jointly explained 71% of the variation in A_n. Structural equation modeling further suggested that drought stress restricted the photosynthetic benefits of elevated CO₂ primarily through stomatal closure, concurrently associated with stress-related declines in pigment stability and photochemical performance. These findings suggest that the carbon sink potential of Chinese fir plantations under future CO₂-enriched climates may be strongly constrained by water deficits. Full article

Background: Rice breeding requires faster development of high-yielding, climate-resilient, resource-efficient, and high-quality cultivars for production systems exposed to environmental variability and increasing input constraints. Genomic selection offers an opportunity to predict breeding value before extensive field evaluation, although its effectiveness depends on the integration of genomic, phenotypic, and environmental information. Methods: This narrative review critically examines recent advances in genomic selection for rice and its integration with high-throughput genotyping, high-throughput phenotyping, machine learning, multi-environment prediction, and speed breeding. Results: Genome-wide marker data can support early ranking of breeding materials for grain yield, grain quality, disease resistance, drought tolerance, salinity tolerance, and nutrient-use efficiency. Prediction performance is influenced by trait architecture, marker density, training-population size, genetic relatedness between training and candidate populations, phenotypic data quality, and genotype-by-environment interaction. Red-green-blue, multispectral, hyperspectral, thermal, and light detection and ranging platforms can generate temporal traits associated with plant architecture, biomass, water status, nutrient status, and stress responses, which may improve prediction under suitable population and validation designs. Speed-breeding systems shorten generation intervals and facilitate rapid advancement, recurrent selection, and recycling of superior parental lines. Conclusions: Integrated breeding pipelines that combine genomic prediction, high-throughput phenotyping, environmental data, and speed breeding can improve selection efficiency and shorten rice improvement cycles. Wider adoption will require affordable technology platforms, standardized data systems, multi-environment validation, breeder capacity development, and collaborative data-sharing frameworks for smart and greener agriculture. Full article

Cotton (Gossypium spp.) is the world’s most important fiber crop for the textile industry. Drought stress can adversely affect cotton production and quality, particularly in arid and semi-arid regions. Biochar, produced from biomass through pyrolysis, has the potential to alleviate drought stress in cotton production through improving soil properties and enhancing plant nutrition. The objectives of this study were to evaluate the effects of biochar produced from southern yellow pine (Pinus spp.) on cotton seedling emergence and growth, yield and its component traits, and fiber quality traits under field drought-stressed, arid conditions in the U.S. over two years. Six genotypes were evaluated in 2024, and three of these genotypes were evaluated following a single application of biochar at four rates (0, 6.25, 12.5, and 25.0 t ha⁻¹) applied at the beginning of the study. Significant genotypic differences were observed in both years, as expected. No genotype × biochar interaction was detected, indicating that different cotton genotypes responded similarly to biochar application. Groundcherry (Physalis acutifolia) infestation was unexpectedly higher, and cotton seedling growth was reduced in the biochar-amended plots compared with the non-biochar control in 2024, but these effects were not observed in 2025. Plots amended with 12.5 and 25.0 t ha⁻¹ biochar had significantly higher soil moisture than those receiving 0 or 6.25 t ha⁻¹ biochar. Estimated seedcotton yield was the highest in plots receiving 12.5 t ha⁻¹ biochar in both years and was significantly greater than that of the non-biochar control, with 18.3 and 8.4% increases in 2024 and 2025, respectively. Biochar had no significant effects on fiber length, uniformity, strength, elongation, and micronaire in either year, except that 6.25 and 12.5 t ha⁻¹ biochar rates increased elongation and 25.0 t ha⁻¹ biochar rate decreased micronaire. These results indicate a single biochar application had a positive, although diminishing, effect of biochar on cotton productivity during the first two years under drought stress, while having little to no effects on fiber quality. Full article

Abies koreana Wilson (Korean fir) and Abies nephrolepis (Trautv. Ex Maxim.) Maxim. (Khingan fir) are ecologically and economically significant coniferous species in East Asia. However, morphological similarities and hybridization complicate species identification, affecting conservation, forestry management, and commercial activities. Here, we developed a species-specific DNA marker using single nucleotide polymorphisms (SNPs) within the mitochondrial nad5 intron 1 region to discriminate between A. koreana and A. nephrolepis. In particular, PCR amplification and sequencing analyses of candidate drought and heat stress-responsive genes as well as mitochondrial nad5 intron 1 and nad5 intron 4 revealed a species-specific T-to-G substitution in nad5 intron 1. Allele-specific primers were designed, and competitive allele-specific labeled light emission technology was employed for SNP detection. The primers were validated using real-time PCR, achieving high specificity and reliability. Overall, the molecular diagnostic tool offers a practical solution for accurate species identification, aiding conservation efforts and sustainable resource management. Full article

Climate variability represents a major threat to agricultural systems, particularly in arid and semi-arid regions such as the Beni-Amir irrigated perimeter, located in the Tadla plain in central Morocco. In this perimeter, olive trees are exposed to multiple environmental and management-related factors that are associated with variations in phenology and vegetation vigor, such as successive drought episodes. This study represents a spatio-temporal assessment of drought impact on olive using satellite- derived vegetation indices from Sentinel-2 imagery and precipitation satellite data from CHIRPS over the period 2015–2024. The Standardized Precipitation Index (SPI-12) was used to identify wet and dry phases over this period. The results indicate an alternation of dry and wet periods between 2015 and 2021, followed by a predominance of dry conditions from September 2021. Over the same period, the time series of the Normalized Difference Vegetation Index (NDVI) and the other vegetation indices reveals marked interannual variability and a progressive degradation of olive tree phenological cycles. A land cover map derived from a supervised support vector machine (SVM) under three classification scenarios achieved high overall accuracies exceeding 94%. Post-classification change detection highlights a substantial reduction in mapped olive-growing areas between 2016 and 2024, with an estimated 72% loss of the initial area. The findings reported in this study indicate that the succession of drought episodes may have contributed to olive grove degradation, including disruptions in phenological cycles and a decline in maximum NDVI values. Even the most resilient olive groves appeared affected following the severe drought period after 2021. The study underscores the usefulness of satellite-derived vegetation indices and drought indicators for the effective monitoring of drought-related stress and supporting improved management practices under climate change. Full article

Early detection of contrasting water-stress types is important for understanding plant stress responses and improving water-stress management in forest seedlings. In this study, three-year-old Pinus tabuliformis seedlings were exposed to control (CK, 75–85% of field capacity), drought (D, 25–35% of field capacity), waterlogging (WL, water level flush with the soil surface), and water flooding (WF, water level 2 cm above the soil surface) treatments. Each treatment included 15 independent seedlings at each sampling date, resulting in 420 seedlings across four treatments and seven sampling dates. Needle water potential (Ψw), total chlorophyll content (Chl), maximum photochemical efficiency (Fv/Fm), indole-3-acetic acid (IAA), abscisic acid (ABA), and electrical impedance spectroscopy (EIS) parameters were measured to compare the temporal responses of physiological and electrical traits under different water conditions. EIS showed clear treatment-dependent changes under all stress treatments, with larger changes observed under WF and WL than under D at the treatment levels and durations evaluated in this study. Based on the present discrete sampling schedule, the real (Re) and imaginary (Im) components showed statistical separation among the four treatments in all six pairwise comparisons of the four treatments on Day 7, whereas ABA and Ψw showed separation on Day 11, Fv/Fm on Day 18, and IAA and Chl on Day 25. These results indicate that Re and Im showed treatment-dependent divergence at earlier evaluated sampling dates than the selected physiological variables. Exploratory CLAFIC analysis further indicated group-level spectral separation between CK and WL/WF on Day 3 and between CK and D on Day 7. Overall, EIS-derived features may provide useful information on early electrical responses of P. tabuliformis seedlings to contrasting water conditions. However, further validation using independent datasets, standardized measurement procedures, and field or nursery conditions is required before EIS can be applied as a practical tool for water-stress assessment. Full article

The DUF538 gene family, harboring unknown functional proteins, has been reported to take active roles in plant development and response to adversities, while few studies of genome-wide identification and functional verification have been performed in cotton. Hence, two ancestral diploid species, G. arboretum and G. raimondii, and two cultivated tetraploid ones, G. hirsutum and G. barbadense, were chosen in this study to investigate the cotton DUF538 gene family, resulting in 37, 37, 70, and 70 members identified, respectively. A phylogenetic tree was constructed on these cotton DUF538 genes, together with 22 A. thaliana ones, which were divided into seven groups unevenly distributed across nearly all chromosomes. High-degree conservatism, while rich in diversity, was separately observed in gene structure and conserved motif analyses between the same groups and different groups, and a great number of gene-replication events were detected from intraspecific and interspecific collinearity analyses, implying this was the driving force for DUF538 family expansion. Multiple cis-acting elements relevant to adversity-stress responses were found in the promoter region, which were consistent with the transcriptome expression analyses in response to low-temperature and drought stress and Verticillium wilt infection. Coincidentally, GhDUF538-7 showed the core position in the protein–protein interaction network and was identified in the overlapping region of the interval of four reported VW resistance-related QTLs. The gene function of GhDUF538-7 was verified via gene cloning, relative expression-pattern detection, and virus-induced gene silencing (VIGS) experiment. The TRV:DUF538-7 plants showed more serious VW symptoms, significantly severe disease indices, relatively higher fungal biomass, and increased brown vascular bundles compared with TRV:00 plants. Significantly lower expression levels of marker genes PR4 and MYC2 in jasmonate signaling pathways indicated GhDUF538-7 as a potentially positive regulatory factor in plant defense via hormone signal transduction. This study not only broadened the research perspective of evolution and functional differentiation of the cotton DUF538 gene family, but it also revealed the cooperative relationship between DUF538-7 and the JA pathway for further molecular mechanisms of cotton resistance to VW infection. Full article

UK forestry faces increasing drought risk under climate change, raising concerns about the resilience of Sitka spruce, the UK’s dominant commercial conifer. This study assessed whether hyperspectral vegetation indices can detect intraspecific drought responses to support resilience screening. An eight-week controlled drought experiment was conducted on 60 grafted Sitka spruce trees representing six clonal groups from the UK breeding population. Needle-level hyperspectral reflectance was used to derive vegetation indices associated with chlorophyll status, photoprotective pigments, and water content, alongside chlorophyll fluorescence (Fv/Fm). Pigment-based and red-edge indices showed the strongest sensitivity to drought, with ARI1 increasing by up to 1.2 under drought relative to controls, while water-related indices captured later-stage hydraulic decline. Clonal variation was detected in the timing and magnitude of pigment regulation, water loss, and photosynthetic impairment, indicating contrasting drought-response trajectories among clones. These results demonstrate that hyperspectral approaches enable rapid, non-destructive detection of physiologically meaningful drought responses and can support the identification of drought-resilient genotypes for climate-adaptive forest management. Full article

WPR (WEB1/PMI2-related) genes play a crucial role in regulating chloroplast movement and leaf coloration in plants. Previous studies have shown that these genes are implicated in leaf yellowing, both in Arabidopsis thaliana and in Paulownia fortunei following infection with Paulownia witches’ broom. To investigate the functions of the ZjWPR genes in jujube, bioinformatics methods were employed to identify the ZjWPR gene family in jujube, analyze their protein physicochemical properties, gene structure, evolutionary relationships, and cis-acting elements in this study. The results revealed that the ZjWPR gene family in jujube comprised 10 members. Phylogenetic analysis showed that WPR genes were divided into two classes, with ZjWPR genes distributed across three subgroups within Class II. Conserved motif analysis indicated that motif 2, motif 3, motif 7, and motif 8 were the most highly conserved and most genes exhibited similar structures. Cis-element analysis in their promoter suggested that ZjWPR genes were regulated by multiple hormones and were associated with stress responses such as low temperature and drought. Moreover, all ZjWPR genes contained light-responsive elements. Expression analysis of the ZjWPR gene family under Jujube Witches’ Broom (JWB) stress showed that ZjWPR4 and ZjWPR5 were significantly up-regulated in JWB-susceptible jujube cultivars following phytoplasma infection, whereas no significant changes were detected in JWB-resistant cultivars. Additionally, the expression levels of ZjWPR2, ZjWPR3, and ZjWPR6 were also altered in response to infection, suggesting their potential involvement in the response to JWB stress and the associated leaf chlorosis process. Moreover, transient overexpression of ZjWPR4 and ZjWPR5 in sour jujube leaves led to significant reductions, in critical photosynthetic parameters, including Fv/Fm, Fq′/Fm′, and ETR compared with WT, thereby reinforcing their functional contribution to JWB-associated leaf yellowing. This study provides valuable insights for further functional characterization of the ZjWPR gene family in mediating JWB-induced leaf yellowing and related metabolic pathways. Full article

Compound flash drought–heatwave extremes (FDHW) expose vegetation to rapid water and heat stress, but regional assessments often conflate event detection with vegetation response and rarely resolve delayed canopy trajectories. We quantified FDHW across China’s Northeast Black Soil Region during the 1995–2024 growing seasons using ERA5-Land soil-moisture and temperature thresholds, applied a spatiotemporal graph neural network to regularize threshold-derived event masks, and reserved AVHRR NDVI for independent post-event impact assessment. Flash drought and FDHW frequencies exhibited strong interannual variability rather than a significant monotonic trend. FDHW occurrence increased from 3.8 to 4.8 d per growing season between 1995–2005 and 2016–2024, but the Theil–Sen trend was near zero (0.05 d per decade). Land–atmosphere composites indicate progressive soil-moisture depletion before FDHW occurrence and a transition from latent to sensible heat release roughly three days before maximum temperature anomalies. NDVI composites revealed a delayed greenness response: anomalies were negative through the first two post-event weeks, reached their minimum approximately one week after the reference FDHW grid-day, and then partially recovered during days 16–30. Mean NDVI suppression was modest (short-term −0.009; long-term −0.006), but persistent negative anomalies remained in 12.1% of southern cropland-dominant trajectories and 10.7% of northern forest–crop ecotone trajectories. These results show that FDHW impacts in the NBSR are expressed less as a steady rise in event frequency than as delayed and spatially heterogeneous vegetation stress, highlighting the need for post-event monitoring windows and cross-sensor validation to support agricultural risk assessment and adaptation planning. Full article