Search Results (3,253)

Dry direct seeding (DDS) is a water-saving and high-efficiency rice cultivation system. However, drought stress during DDS severely constrains seedling establishment. This study used the conventional rice variety Zhonghua 11 (ZH11) and the drought-tolerant hybrid Hanyou 73 to investigate the effects of exogenous silicon (Si) on seed germination and seedling growth under drought stress, and to explore the underlying mechanisms of Si-enhanced drought tolerance. Drought stress was imposed using PEG-6000 simulation and pot experiments with different soil relative water contents (60%, 45%, 25%, and 10%). Si treatment significantly alleviated simulated drought inhibition of seed germination, increasing germination percentage and index, improving seedling growth in both varieties. Under simulated DDS conditions, Si significantly improved plant height, biomass, and root development, while maintaining higher net photosynthetic rate, stomatal conductance, intercellular CO₂ concentration, transpiration rate, and chlorophyll content. Meanwhile, Si reduced oxidative damage by promoting proline accumulation, enhancing peroxidase (POD) and catalase (CAT) activities in both leaves and roots, reducing malondialdehyde (MDA) accumulation, and upregulating the expression of key drought-responsive genes (SNAC1, DREB1A, SKIPa, P5CS2). Furthermore, Si upregulated the expression of genes involved in abscisic acid (ABA) (ABA1, ABA2, MHZ5, ABI3) and jasmonic acid (JA) (AOS2, AOS3, JAR1, JAR2, MYC2, COI1a) biosynthesis and signaling. Compared with the wild-type, the ABA signaling mutant abi3 and the JA signaling mutant myc2 exhibited significantly attenuated improvement of plant growth by Si treatment. Collectively, Si enhances antioxidant capacity and osmotic adjustment, maintains photosynthetic function, and is associated with the activation of ABA and JA signaling pathways, which together alleviate the inhibition of rice seedling establishment under DDS-associated drought stress. Our findings provide a theoretical basis for the application of Si fertilizer in DDS rice production. Full article

The dormancy of lilies is an important physiological process involving vernalisation and the differentiation and maturation of flower buds. We have cloned an aquaporin, SbP1P1;2, from the Lilium ‘Siberia’. Subcellular localisation analysis indicates that it is a protein that is localised to the plasma membrane in Nicotiana benthamiana. VIGS-mediated transient silencing revealed that silencing the SbPIP1;2 gene inhibited the development of lily flower buds, while those in the control group differentiated earlier to the anther primordia stage. Notably, the ABA levels in the control group had dropped significantly by day 63, suggesting that dormancy ended earlier than in the treatment group. The test plants’ phenotype is characterised primarily by the fact that silencing the SbPIP1;2 gene inhibits both flower bud development and root growth. The dormancy-to-sleep transition phase (PS vs. TS) was also the period during which the largest number of differentially expressed genes was observed. KEGG enrichment analysis indicates that starch and sucrose metabolic pathways are most active from the onset to the completion of dormancy release and that significant differences occur in several key genes within these pathways. These include alpha-trehalose-phosphate synthase (TPS), sucrose phosphate synthase (SPS), trehalase (TREH), fructokinase-1 (E2.7.1.1), beta-glucosidase (bglB), glycogen synthase (glgA), glucose-6-phosphate isomerase (GPI), and ectonucleotide pyrophosphatase/phosphodiesterase family members 1 and 3 (ENPP1/3). The discovery that aquaporins promote dormancy breaking in lilies is a highly successful case study for aquaporin research in flowers. Full article

Phenylalanine ammonia-lyase (PAL) is the rate-limiting enzyme in the phenylpropane metabolic pathway, which is crucial for plant disease resistance. However, the functional roles of specific PAL members in lily defense against gray mold (Botrytis elliptica) remain unclear. Using the resistant lily cultivar ‘Sorbonne’, metabolomics analysis revealed that phenylpropane metabolites were significantly induced upon pathogen infection. Combined second- and third-generation transcriptome sequencing identified eight PAL family members. Among them, LhSorPAL1 and LhSorPAL2 were strongly induced by B. elliptica and were selected for further analysis. Both recombinant proteins exhibited PAL enzymatic activity catalyzing cinnamic acid production from L-phenylalanine. Overexpression of LhSorPAL1 or LhSorPAL2 in lily via Agrobacterium-mediated transformation had no obvious effect on plant growth but significantly increased the accumulation of lignin, flavonoids, and total phenols upon pathogen challenge, leading to enhanced resistance to gray mold. Conversely, antisense expression of LhSorPAL1 or LhSorPAL2 reduced the accumulation of these metabolites. Promoter analysis revealed that both LhSorPAL1pro and LhSorPAL2pro contain methyl jasmonate (MeJA)-, abscisic acid (ABA)-, and transcription factor-binding cis-elements. Collectively, these results demonstrate that LhSorPAL1 and LhSorPAL2 positively regulate lily resistance to B. elliptica by promoting phenylpropane metabolism, providing candidate genes for molecular breeding. Full article

Rapeseed (Brassica napus L.) growth and productivity are severely constrained by drought stress worldwide. Stomata are central regulators of plant transpiration and gas exchange, and therefore, represent key targets for enhancing water-use efficiency and drought tolerance. The transcription factor ABSCISIC ACID INSENSITIVE 4 (ABI4), a key regulator of the abscisic acid (ABA) signaling pathway, plays crucial roles in plant abiotic stress responses and stomatal regulation. Nevertheless, the biological functions of BnaABI4 in B. napus remain largely unclear. In this study, four BnaABI4 paralogs were identified in the elite rapeseed cultivar ZS11 through genome-wide identification and comprehensive bioinformatic analyses. Each BnaABI4 protein harbors only one conserved AP2 domain, and their promoters contain multiple stress/hormone-responsive cis-regulatory elements (CREs). We subsequently generated BnaABI4-4 overexpression (OE) lines as well as BnaABI4 CRISPR/Cas9-mediated knockout (KO) transgenic lines. Phenotypic assays demonstrated that OE line had reduced transpiration rate (Tr), stomatal conductance (Gs) and stomatal density, along with enhanced drought tolerance, whereas KO lines showed the opposite phenotype. Transcriptome profiling identified numerous differentially expressed genes (DEGs) enriched in biological pathways associated with stomatal regulation, ABA signal transduction, and drought acclimation. Further Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses confirmed significant enrichment of DEGs in processes including stomatal development, stomatal movement, reactive oxygen species (ROS) homeostasis, and drought tolerance. Collectively, our findings demonstrate that BnaABI4 negatively regulates stomatal density while positively contributing to drought tolerance in B. napus. This study lays a mechanistic foundation for genetic improvement and molecular breeding of drought-tolerant rapeseed cultivars. Full article

Tobacco is a plant with a wet stigma, which produces reactive oxygen species (ROS) and abscisic acid (ABA) which is important for in vivo pollen germination. Furthermore, ROS can be linked to growth processes, stimulating or inhibiting them. However, to what extent do differences in the redox environment and ABA level on the stigma and in pistil tissues correlate with flower growth, pollination success and resulting fruit parameters? We investigated redox homeostasis and ABA concentrations in stigma exudates of two tobacco lines (“Samsun” and “Fortune”) with different floral organ size and seed production. Fortune has longer flowers, larger fruits, and more seeds than Samsun. We report here that Samsun has a higher total oxidative capacity in stigma exudate, and possibly also higher NO level, than Fortune, as estimated by electron paramagnetic resonance spectroscopy. Fortune has a higher ascorbate peroxidase (APX) content in stigma tissues, as determined by Western blot analysis, and a higher ABA concentration in stigma exudate. Analyzing ROS levels and enzyme activity during the elongation stage in buds, we found that shorter Samsun styles had higher ROS levels, but they also had higher superoxide dismutase (SOD) and APX activity. The results of this study may help in developing approaches to a targeted increase in flower size and seed productivity. Full article

High temperature during flowering and grain filling severely reduces rice yield and grain quality. Split potassium (K) fertilization can mitigate such heat-induced damage, yet its mechanisms linking grain filling, endogenous hormones and grain performance remain unclear. Here, a two-year pot experiment was conducted to explore the effects of split K application on rice yield, quality and hormonal metabolism under high temperature. Four treatments included ambient temperature with full basal K (AT-K₁₀₀), high temperature with full basal K (HT-K₁₀₀), and two split K regimes under high temperature (HT-K₇₀₊₃₀, HT-K₃₀₊₇₀). Split K application decreased abscisic acid (ABA) levels at 5 days after anthesis (DAA), increased indole-3-acetic acid (IAA), zeatin riboside (ZR) and gibberellin A3 (GA₃) at 5 DAA, and maintained higher IAA and GA₃ levels until 20 DAA. The ratios of ABA/IAA and ABA/GA₃ were also reduced at both 5 and 20 DAA. These hormonal alterations optimized grain-filling dynamics, prolonged active filling duration and improved middle- and late-stage filling rates, thereby promoting grain weight accumulation and suppressing chalkiness formation. Compared with HT-K₁₀₀, HT-K₇₀₊₃₀ increased yield by 8.75%, which was attributed to improved seed-setting rate and 1000-grain weight. HT-K₃₀₊₇₀ enhanced spikelet number per panicle, seed-setting rate and 1000-grain weight, but significantly decreased effective panicles, resulting in no obvious yield advantage. Furthermore, split K application effectively reduced grain chalkiness, with a more pronounced effect at a higher panicle-stage K proportion. Under ongoing global warming, K management can be tailored to production goals: higher basal K is preferable for yield pursuit, while increasing panicle K topdressing effectively improves grain quality. Full article

This study investigates the “competence–performance gap” between cognitive ability (measured by the WISC-IV) and actual adaptive performance (measured by the ABAS-II) in children with autism spectrum disorder (ASD), and examines the moderating role of family environment, specifically parental education levels. We applied Latent Profile Analysis (LPA) to cross-sectional data from 3246 children with ASD (aged 6–16 years). The analysis identified three distinct cognitive–adaptive subgroups: the Balanced High-Functioning group (33%), the Classic Mismatch group (44%), and the Cognitively Vulnerable group (23%). Notably, the Classic Mismatch group was characterized by adaptive performance that significantly trailed cognitive potential. Multinomial logistic regression revealed that maternal education—but not paternal education—significantly predicted a child’s likelihood of being in the “Balanced High-Functioning” group. This moderating effect was especially pronounced during the school-age years. These findings highlight the critical role of environmental factors in the translation of intellectual potential into practical social adaptive functioning, providing theoretical support for targeted family-based interventions. Full article

Plants are constantly exposed to diverse abiotic stresses, including drought, salinity, and extreme temperatures, which severely limit growth, development, and crop productivity. These stresses disrupt physiological, biochemical, and molecular processes, leading to reduced photosynthesis, altered water and ion homeostasis, and accumulation of reactive oxygen species (ROS). Plants have evolved sophisticated sensing and signaling mechanisms to perceive these stresses, with phytohormones playing central roles in mediating adaptive responses. Key hormones, including abscisic acid (ABA), salicylic acid (SA), jasmonates (JAs), gibberellins (GAs), auxin (IAA), ethylene (ET), melatonin, and strigolactones (SLs), regulate stress tolerance by controlling stomatal behavior, root architecture, antioxidant systems, osmolyte accumulation, and stress-responsive gene expression. Importantly, these hormones operate within an intricate network of crosstalk, integrating multiple signaling pathways to balance growth and stress adaptation. Interactions among ABA, GA, JA, SA, auxin, ET, SLs, and melatonin enable plants to coordinate transcriptional regulation, protein phosphorylation, and ROS signaling, optimizing survival under fluctuating environmental conditions. Understanding the molecular mechanisms underlying hormonal crosstalk and their roles in abiotic stress tolerance provides valuable insights for developing resilient crops in the face of climate change. Full article

Plant U-box E3 ubiquitin ligases (PUBs) are involved in various biological processes in response to abiotic stress. Recent studies have shown that E3 ubiquitin ligases can regulate the production of important compounds in medicinal plants by targeted degradation of transcription factors. Abscisic acid (ABA), a plant stress response hormone, can cause changes in the content of the medically important monoterpene indole alkaloids (MIAs) in U. rhynchophylla. In this study, we explored the relationship between UrPUB gene expression and MIA content. ABA was applied to tissue-cultured seedlings of U. rhynchophylla, resulting in consistent changes in the content of four MIAs. Seventy-three UrPUB genes were identified and bioinformatically characterized from the genome sequence of U. rhynchophylla. The expression levels of transcription factors involved in regulating the biosynthesis pathway of MIAs and UrPUB genes with higher RNA transcript levels in the roots were determined. Co-expression association analysis revealed that UrPUB17, UrPUB40, UrPUB41, UrPUB44 and UrPUB55 negatively correlate with UrGATA8 and UrWRKY37 under ABA stimulation. Based solely on these correlation data, we hypothesize that these UrPUBs might regulate MIA biosynthesis via ubiquitination of UrGATA8 and UrWRKY37, but direct evidence (protein interaction, ubiquitination, degradation, or genetic manipulation) is lacking. This study identified the UrPUB gene family in the U. rhynchophylla genome and proposes this ubiquitination model as a testable hypothesis, not a demonstrated mechanism. These findings provide new insights into the biological function of the PUB family in response to ABA. Full article

m⁶A is an important RNA modification involved in post-transcriptional regulation in plants. However, putative m⁶A writers and erasers in G. biloba remain poorly characterized. In this study, a total of 17 candidate m⁶A regulatory genes, including 8 writers and 9 erasers, were identified through genome-wide analysis. Phylogenetic and structural analyses indicated that these proteins are generally conserved, with some members showing potential functional divergence. Promoter analysis revealed abundant hormone- and stress-responsive cis-elements, and expression profiling showed tissue-specific patterns and dynamic responses to ABA, MeJA, and NaCl treatments, with erasers exhibiting greater transcriptional responsiveness than writers. In addition, protein interaction network and phase separation predictions suggested potential roles in RNA methylation-related processes. These results provide a foundation for further functional studies of m⁶A regulation in G. biloba. Full article

Lithocarpus litseifolius is a medicinal tea plant recognized for its sweet flavor and anti-diabetic properties, but its limited leaf yield under cultivation restricts its economic sustainability. Melatonin (MLT) is a multifunctional plant growth regulator, but its roles in leaf growth under normal conditions remain not fully understood. Herein, we investigated the effects and mechanisms of foliar-applied MLT on L. litseifolius seedlings, including growth indices, phytohormone profiles, photosynthetic characteristics, and transcriptome alterations. The 100 μM MLT treatment significantly enhanced leaf dry weight by 33.8% and leaf dry matter content by 22.2% compared to the control group. MLT decreased both free and bound abscisic acid (ABA), while increasing gibberellins (GAs), 5-deoxystrigol, auxins (e.g., IAM), and cytokinins (e.g., cZ9G). Additionally, exogenous MLT improved photosynthetic rate, stomatal conductance, chlorophyll content, and soluble sugars in leaves. RNA-seq revealed that MLT up-regulated DEGs involved in hormone biosynthesis and signaling (CYP707A, BAK1, D14, CCD1, and IAA6), photosynthesis (PsbC/B, PetH, PsaB, and ATPase β), and sugar metabolism (WAXY, glgC, and otsB). Our results demonstrate that MLT promotes leaf dry matter accumulation through coordinated phytohormone homeostasis, photosynthetic enhancement, and transcriptional regulation, offering a cost-effective strategy to improve leaf yield in L. litseifolius. Full article

Plant aging and senescence are key determinants of lifespan, yet the coordinated changes in endogenous polyamines and hormones during long-lived tree aging remain largely unclear. Cinnamomum camphora exhibits sequential senescence from leaves to trunk, with leaf physiology shifting toward senescence around 450 years. This study aimed to clarify the patterns of polyamines and hormones across a wide age gradient (10–810 years) and their associations with aging in ancient C. camphora. Newly expanded leaves were analyzed using curve fitting, correlation, regression, and path analysis. Tree age significantly influenced most polyamine and hormone indices, except for indole-3-acetic acid (IAA), abscisic acid (ABA), and salicylate glucoside (SAG). Spermidine (Spd) and gibberellic acid (GA) were negatively correlated with aging, and cytokinin (CK) and cadaverine (Cad) were positively correlated with aging. Free salicylic acid (SAF) was closely related to the senescence transition point. Polyamines and hormones interacted strongly. Cad was positively correlated with CK, and Spd was positively correlated with GA. A model combining Spd, GA/ABA, and CK/GA reliably predicted ancient tree age. Overall, Spd and CK exhibited the strongest negative and positive correlations with aging, respectively, providing insights into the physiological regulation of longevity in ancient trees. Full article

Background: This study examined peer interactions among late-diagnosed autistic adolescents, focusing on biological sex differences. Methods: Participants included 61 adolescents aged 12–18 years (31 boys, 30 girls) with an Intelligence Quotient (IQ) > 75, all diagnosed within the past three years. Peer interactions were assessed using the APIOS-A, an adapted version of the preschool observational tool (APIOS). Parents reported on autistic traits via the Social Responsiveness Scale (SRS-2), which measures social communication difficulties; socialization skills through the Adaptive Behavior Assessment System (ABAS-II), which assesses adaptive functioning; and behavioral problems using the Child Behavior Checklist (CBCL), which identifies emotional and behavioral issues. These measures were utilized to compare social profiles across sexes. Results: The APIOS-A demonstrated good reliability for identifying socio-communicative difficulties in both boys and girls. Findings indicated that boys and girls showed similar peer interaction challenges, with subtle differences in conversational reciprocity, cognitive flexibility, and humor use. Associations between behavioral characteristics and peer patterns varied by sex, highlighting the importance of tailored approaches. Conclusions: These results underscore the need for sex-sensitive assessment tools and tailored interventions for late-diagnosed autistic adolescents. Integrating observational and parental measures may enhance understanding and support their social development. Full article

Alternative splicing (AS) coupled with nonsense-mediated decay (NMD) is an important post-transcriptional mechanism that regulates the expression of many genes, including serine/arginine-rich (SR) proteins across eukaryotes. In plants, SR proteins participate in diverse developmental processes and stress responses, particularly in abscisic acid (ABA) signaling. However, the functional differences among individual splice isoforms of SR proteins remain poorly understood. Here, we investigated SCL30a, a plant-specific SR protein in Arabidopsis thaliana. By integrating third-generation long-read transcriptome sequencing, NMD stability assays, and subcellular localization analyses, we identified five alternatively spliced SCL30a transcripts. Among them, SCL30a.2 and SCL30a.3 contain premature termination codons (PTCs), display nucleocytoplasmic localization, and are rapidly degraded through the NMD pathway. In contrast, the other three isoforms, SCL30a.1, SCL30a.4, and SCL30a.5, retain an intact RS domain and localize exclusively to the nucleus. Functional analyses showed that SCL30a acts as a positive regulator of ABA signaling. Loss-of-function mutants of SCL30a displayed reduced ABA sensitivity in both root growth and seed germination assays, whereas complementation or overexpression of three stable isoforms of SCL30a (SCL30a.1, SCL30a.4, and SCL30a.5) enhanced ABA responsiveness. Transcriptome analysis further showed that the expression of a subset of ABA-related genes, particularly SnRK2.6, was significantly altered in ABA-treated scl30a mutants and SCL30a.1-OE lines compared with WT plants. In addition, genetic evidence showed that overexpression of SnRK2.6 rescued the ABA-insensitive phenotype of the scl30a mutant. Together, these findings suggest that SnRK2.6 may function as a candidate downstream component associated with SCL30a-mediated ABA responses. Full article

Systemic regulation of photosynthesis is crucial for plant survival in variable environments, yet the hormonal mechanisms coordinating photosynthetic responses to local stimuli are not fully elucidated. This study investigates the interplay between jasmonates (JAs) and abscisic acid (ABA) in systemic photosynthetic responses induced by local heat stress in Arabidopsis thaliana. Using phytohormone quantification, chlorophyll fluorescence and gas exchange measurements in wild-type and transgenic plants impaired in JA biosynthesis, this study showed that local heating-induced variation potential propagation triggers JA biosynthesis in systemic unstimulated leaves, followed by changes in ABA content, stomatal conductance and photosynthetic activity. Rapid systemic increases in jasmonoyl-L-isoleucine (JA-Ile) levels are essential for the systemic decreases in stomatal conductance and the consequent reduction in carbon assimilation. Systemic increases in JA-Ile levels also contribute to systemic accumulation of ABA, likely to maintain reduced stomatal conductance. Thus, the data support a model in which JA-Ile acts as a mediator of early stages of the systemic photosynthetic response, whereas ABA likely contributes to late stages of this response. These results highlight the complex integration of hormonal signals in the regulation of photosynthesis under stress conditions. Full article