Search Results (834)

Brassica rapa is widely cultivated in alpine and cold mountainous regions due to its strong cold tolerance. However, lodging severely limits its yield and quality. This study integrated agronomic traits, stem microstructure, and transcriptomic profiles to explore the mechanism of lodging resistance by comparing a resistant cultivar (Ganyou 3064, GY) and a susceptible cultivar (Tianyou 2022, TY) across four developmental stages (full flowering, final flowering, podding, and maturity). At the four growth stages, the stem breaking strength of GY was 1.71, 1.93, 1.88, and 1.88 times that of TY, respectively. Compared with TY, the gravity center height of GY was decreased by 25.04%, 16.6%, 11.18%, and 8.98% at these four stages, respectively. Similarly, the lodging index of GY was decreased by 65.94%, 55.08%, 56.06%, and 55.63% compared with TY, respectively. Biochemical and anatomical analyses revealed that compared with TY, the lignin content of GY increased by 1.93%, 2.7%, 3.05%, and 3.42% at the four stages, while the cellulose content increased by 92.75%, 45.32%, 44.4%, and 49.92%, respectively. Meanwhile, the epidermal thickness, cortical thickness, vascular bundle length, vascular bundle area, and vascular bundle density of GY were also significantly increased. Transcriptomic and KEGG pathway analyses revealed a predictive defense mechanism of GY. At the final flowering stage, GY showed pre-activation of hormone and MAPK signal transduction, as well as phenylpropanoid biosynthesis; it shifted to energy supply and sustained cell wall reinforcement at the podding stage. In addition, upregulated genes in phenylpropanoid biosynthesis (such as PAL3, CCoAOMT, and CAD9) indicated that enhanced stem lignification is a key molecular determinant of lodging resistance. In summary, GY enhances its lodging resistance through coordinated morphological and transcriptional regulation. This study is the first to integrate the lodging characteristics of Brassica rapa, offering valuable candidate genes and phenotypic markers for molecular breeding. Full article

Eucalyptus spp. are the most important timber and pulpwood species in southern China. This tree species is frequently and severely damaged by the leaf-eating pest Buzura suppressaria, which significantly impairs photosynthesis and hinders the healthy and sustainable development of the Eucalyptus industry. To investigate the defensive responses of Eucalyptus urophylla × Eucalyptus grandis to pest (B. suppressaria)-feeding and leaf-clipping stress, this study measured the temporal changes in defense enzyme activities and defense compounds in Eucalyptus under conditions of pest-feeding and leaf-clipping stresses, aiming to provide a theoretical basis for resistance breeding in Eucalyptus. The results show that pest-feeding and leaf-clipping stress groups significantly affected the peroxidase (POD), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) activities in Eucalyptus leaves. Within a short period after stress (3 h), POD activity was significantly reached 444.83 U by leaf-clipping stress, whereas it was significantly inhibited (34.83 U) by pest-feeding stress. PPO activity was significantly enhanced to 95.25 U under pest-feeding stress within 3 h, while leaf clipping induced a lower level of PPO activity (58.75 U). PAL activity was significantly induced to 474.38 U by leaf-clipping stress at 3 h, whereas pest-feeding stress resulted in a moderate increase to 238.00 U. Both pest-feeding and leaf-clipping stresses had significant effects on the contents of defense compounds in Eucalyptus leaves. Within a short period (3 h), both leaf-clipping and pest-feeding stresses significantly induced the accumulation of salicylic acid (0.226 μg/g and 0.326 μg/g, respectively), jasmonic acid (0.239 μg/g and 0.278 μg/g, respectively), and tannin (0.581 μg/g and 0.657 μg/g, respectively). The POD activity and salicylic acid content were identified as the primary factors in Eucalyptus responses to pest-feeding and leaf-clipping stresses. In conclusion, biotic (pest-feeding) and abiotic (leaf-clipping) stresses can induce higher activities of related defense enzymes while also promoting the synthesis of greater quantities of defensive chemical compounds, thereby enhancing the resilience to biotic and abiotic stresses in Eucalyptus. This study provides important practical guidance for insect-resistant Eucalyptus breeding and implementing integrated pest management strategies. Full article

Powdery mildew (PM) is a major fungal disease in cucumber (Cucumis sativus L.) cultivation. Grafting serves as an important agricultural practice for improving disease resistance and stress tolerance in scions. This study aimed to determine the effects of different pumpkin rootstocks on PM resistance in grafted cucumber plants. Susceptible ‘Xintai Mici’ cucumber scions were grafted onto 10 different pumpkin rootstock varieties, with self-grafted plants serving as the experimental control. Grafting significantly promoted plant biomass accumulation compared to the self-grafted control, and this enhancement was positively correlated with the rootstock’s root system size. However, grafted plant growth was still negatively affected by PM infection. Among the 10 rootstocks, seedlings grafted onto rootstock GP8 exhibited the lowest disease index, the slowest spore development, and the strongest PM resistance. While some resistant pumpkin rootstocks failed to confer significant PM resistance to their grafted cucumber scions, rootstock GP8 provided consistent PM resistance to its grafted plants. Furthermore, cucumber grafted onto rootstock GP8 showed a significantly enhanced net photosynthetic rate and increased antioxidant enzyme activities (superoxide dismutase, ascorbate peroxidase, and glutathione reductase). Concurrently, these plants accumulated lower levels of superoxide anions and exhibited the smallest increases in malondialdehyde content among all the grafted combinations. Additionally, during PM infection, the expression levels of salicylic acid biosynthesis-related genes (CsICS1 and CsPAL) and downstream disease resistance genes (CsPR1, CsPR5, and CsNPR1) were significantly higher in scions grafted onto rootstock GP8 compared to self-grafted cucumbers. These results suggest that the enhanced PM resistance in grafted cucumber is significantly influenced by the rootstock, potentially through the regulation of photosynthetic performance, reactive oxygen species metabolism, and the expression of genes associated with the salicylic acid signaling pathway in the scion. Full article

The storage quality of fresh-cut peach fruit is compromised by weight loss and chromatic aberration. In this experiment, taurine at 30 mg L⁻¹ was applied to fresh-cut peaches to evaluate its effect on storage quality. Changes in weight loss, chromatic aberration, antioxidant system, endogenous nitric oxide (NO) metabolism, endogenous hydrogen sulfide (H₂S) metabolism, and phenylpropanoid metabolism were studied. The results indicated that 30 mg L⁻¹ taurine effectively improved the ability to scavenge ROS, including •OH, O₂^•−, MDA, and H₂O₂, by inhibiting the decrease in the activities of SOD and CAT, enhancing POD activity, reducing PPO activity, and maintaining the AsA-GSH cycle. Moreover, taurine treatment increased the activities of 4CL and PAL and retarded the decrease in the activities of SKDH and C4H, thereby improving the accumulation of total phenols, flavonoids, and lignin. These findings showed that taurine mitigated oxidative damage in fresh-cut peaches by enhancing the antioxidant defense system. Exogenous taurine consistently enhanced NOS-like activity while decreasing NR activity in the early storage phase, and elevated the contents of L-Arginine, nitrite, and endogenous NO. Taurine treatment up-regulated the activities of SAT, L-CD, and OAS-TL, thus promoting endogenous H₂S content in fresh-cut peaches. Taurine alleviated weight loss and chromatic aberration in fresh-cut peaches during storage by enhancing the antioxidant system and modulating NO, H₂S and phenylpropanoid metabolism. Full article

Ceylon cinnamon (Cinnamomum verum J. Presl) bark essential oil (CBO) represents a promising source of natural bioactive compounds for biological plant protection. For the first time, the antibacterial and antifungal activity of CBO was systematically evaluated against a curated panel of phytopathogenic strains (IOR collection), revealing broad-spectrum efficacy across both bacteria and filamentous pathogens. This study evaluated its chemical composition, antimicrobial activity against phytopathogens, effects on bacterial metabolic activity, and its ability to induce plant defence responses. CBO was dominated by cinnamaldehyde, linalool, and eucalyptol. The oil exhibited strong antibacterial activity against Dickeya dadantii, Pectobacterium carotovorum, Pseudomonas syringae, and Xanthomonas hortorum as well as antifungal activity against Fusarium graminearum, F. culmorum, Rhizoctonia solani and Phytophthora cinnamomi. Metabolic assays revealed a marked reduction in bacterial metabolic activity, indicating that CBO disrupts physiological processes and inhibits growth. In planta experiments showed that foliar application of CBO stimulated PAL activity in wheat leaves without visible phytotoxic symptoms. These findings demonstrate a multifunctional mode of action of CBO, combining direct antimicrobial effects with the elicitation of plant defence responses, and support its potential application in sustainable crop protection. Full article

Physically Active Learning (PAL) integrates physical activity into classroom teaching and has been shown to benefit students’ cognitive, social, and academic outcomes. Despite these advantages, PAL is not yet sustainably implemented in everyday school practice, highlighting the need for effective professional development (PD) formats for teachers. This randomized controlled experimental study examined how different PD formats, varying in their mode of engagement with ready-to-use PAL materials, affect teachers’ motivation, professional competence, and implementation of PAL. A total of 153 in-service primary teachers participated in a 2.5 h PD training and were randomly assigned to one of three formats: example-based learning, experience-based learning, or problem-solving. Data were collected at pre-test, post-test, and a six-week follow-up using standardized questionnaires. Results showed that teachers in the experience-based format reported significantly higher motivation during the PD training than those in the other formats. Across all formats, attitude and self-efficacy regarding PAL increased over time, whereas no significant gains in knowledge were observed. No significant differences between PD formats regarding overall implementation of PAL were observed. Exploratory analyses indicated a potential advantage of the experience-based format. Overall, the findings suggest that immersive, experience-based PD formats may be particularly effective in fostering teachers’ motivation. Full article

Hydrogen peroxide (H₂O₂) regulates plant metabolism. This study examined its effect on the biosynthesis of specialized metabolites in Baccharis conferta, a medicinal plant rich in phenolics and terpenes. Plants were elicited with 25 µM and 250 µM H₂O₂. Phenolic changes were evaluated by total phenolic content (TPC), total flavonoid content (TFC), phenylalanine ammonia-lyase (PAL) activity, and LC-MS analysis of flavonoids and hydroxycinnamic acids. Meanwhile, terpene changes were evaluated by HPTLC, total terpene content (TTC), and expression of the 1-deoxy-D-xylulose-5-phosphate synthase (Bco-DXS1) gene. H₂O₂ markedly modulated both pathways. Phenolic metabolism was activated, particularly under 25 µM H₂O₂, with PAL activity increasing by 52%, TPC by 42%, and TFC by 50% relative to the control. Chemical analysis revealed that five compounds, including chlorogenic acid, differed significantly across treatments. Gene expression analysis showed that 25 µM H₂O₂ upregulated Bco-DXS1 and increased TTC, whereas 250 µM H₂O₂ repressed gene expression but still enhanced terpene accumulation. Overall, these results suggest that moderate H₂O₂ levels function as a signaling molecule in B. conferta, simultaneously boosting phenolic and terpene pathways. This highlights controlled H₂O₂ elicitation as an effective biotechnological approach to increase the production of valuable metabolites in medicinal plant cultures. Full article

Background: Standard accelerometer summaries obscure meaningful differences in how people move while upright. We introduce an operational two-class Ambulatory Behaviour Framework that separates Ambulatory Tasks—periods of standing and short continuous stepping bouts (<1 min) that are indicative of activity in a single locus—from Ambulatory Journeys—long continuous stepping bouts (≥1 min) that are indicative of movement between locations. Methods: We analysed thigh-worn activPAL3 data from 3545 participants in the age-46 sweep of the 1970 British Cohort Study (24,815 valid monitor-days). Event-based algorithms grouped upright events and classified them as an Ambulatory Task or Journey; linear models examined associations with sitting time and differences by sex and BMI. Results: Mean upright time averaged 6.50 h day⁻¹; Ambulatory Tasks dominated (5.91 h; 90.6% of upright exposure), whereas Ambulatory Journeys contributed 0.61 h (9.4%). Each additional hour of Ambulatory Tasks corresponded to 0.61 h less sitting (β = −0.61 h; 95% CI: −0.63 to −0.61), while an extra hour of Ambulatory Journeys displaced only 0.04 h of sitting (β = −0.04 h; 95% CI: −0.044 to −0.039). Women accumulated significantly more time in Ambulatory Tasks and less sitting time than men. Both upright behaviours declined with increasing BMI. Conclusions: Ambulatory Tasks substantially replace sitting time, whereas Ambulatory Journeys leave sitting essentially unchanged. Interventions to displace sitting should concentrate on fostering frequent, brief, context-embedded tasks throughout the day. This novel framework yields interpretable, sensor-agnostic metrics to target behaviour change and standardise reporting of free-living mobility. Full article

Armillaria solidipes, the causal agent of Armillaria root rot, poses a severe and persistent threat to poplar forest plantations. This study evaluated the biocontrol efficacy of the endophytic bacterium Bacillus velezensis BY6 against this pathogen and elucidated its multimodal mechanisms of action. BY6 application significantly reduced disease severity by 37.19% at 30 days post-treatment. 16S rRNA (V3–V4) microbiome analysis revealed that BY6 reshaped both the rhizosphere and phyllosphere bacterial communities, consistently enriching beneficial taxa, including Pantoea ananatis and members of Acidobacteria, while suppressing opportunistic groups. Concurrently, BY6 activated systemic defenses in poplar, evidenced by enhanced activities of key enzymes PAL and POD, and the upregulated expression of SA/JA pathway marker genes (PR1, JAZ, and COI1), coupled with the downregulation of the auxin transporter gene AUX1. These data indicate that the biocontrol efficacy of B. velezensis BY6 was mediated by a dual mechanism: the modulation of both rhizospheric and phyllospheric bacterial communities, direct elicitation of systemic defense pathways in poplar, which synergistically enhanced resistance against A. solidipes. Full article

Plants respond to ultraviolet B radiation (280–320 nm) with an integrated reaction that includes the reception of the acting stress factor, followed by the generation of reactive oxygen species and damage to macromolecules and membrane structures, as well as changes in cellular metabolism and the formation of protective systems. However, the involvement of key UV-B–related signalling components such as HY5, SPA1 and BIC1 or BIC2 proteins in physiological, biochemical and molecular responses remains insufficiently understood. The effects of 8, 16 and 24 h of UV-B exposure (within an 8 h photoperiod over three days) on the net photosynthetic rate (Pn), chlorophyll fluorescence parameters Y(II) and F_v/F_m, reflecting the functional state of PSII, nonphotochemical quenching (NPQ), pigment contents (Chl(a+b), carotenoids, anthocyanins and UV-absorbing pigments (UAPs) and the expression of key light-induced genes in wild-type Arabidopsis thaliana and spa1, bic1,2 and hy5 mutants were studied. UV-B irradiation resulted in a gradual reduction in the Pn, Y(II), F_v/F_m values and Chl(a+b) but caused a marked increase in the anthocyanin and UAP contents and only minor changes in the carotenoid content. The hy5 mutant presented the lowest net photosynthetic rate (Pn), chlorophyll fluorescence parameters, and chlorophyll and carotenoid contents under all the UV-B exposures. In addition, the accumulation of anthocyanins and UAPs during UV-B treatment was consistently the lowest in hy5. After any UV-B exposure, the highest accumulation of UAPs and anthocyanins was observed in the spa1 mutant, whereas the highest Pn values were detected after 24 h in bic1,2. One of the reasons for the reduced photosynthetic activity and antioxidant capacity in hy5 may be the lower expression levels of CHS and PAL in this variety than in the other genotypes. Our results indicate that HY5 is required to maintain antioxidant responses and photosynthetic performance under repeated daytime UV-B exposure (16.8 kJ m⁻² per day). In contrast, BIC1, BIC2, and SPA1 also contribute to UV-B tolerance, but through distinct regulatory mechanisms and to a lesser extent. Full article

Nitrogen (N) availability strongly regulates plant growth and metabolism, and its deficiency constrains plant development and yield. Silicon (Si) has been reported to enhance plant tolerance to multiple stresses; however, its influence on N metabolism in oats remains poorly understood. This study aimed to investigate the effects of Si on cell wall composition and antioxidant responses in oat genotypes grown under N limitation. Two oat genotypes with contrasting N tolerance were hydroponically cultivated under N-deficient (0.5 mM) or N-sufficient (5 mM) conditions in combination with 0 or 2 mM Si. Growth parameters, N and Si uptake, cell wall structural components, phenylalanine ammonia-lyase (PAL) and tyrosine ammonia-lyase (TAL) activities, antioxidant responses, and oxidative damage were evaluated. In both genotypes grown under N deficiency, Si supply reduced shoot N content while enhancing Si accumulation. Moreover, Si application decreased lipid peroxidation in both genotypes under N-deficient conditions. In the N-sensitive genotype, Si increased cellulose deposition and antioxidant activity, whereas in the N-tolerant genotype, Si reduced lignin content and TAL activity. We conclude that Si supplementation improves the metabolic performance of oat genotypes under N-deficient conditions by modulating nutrient uptake, antioxidant responses, and cell wall composition. Full article

Alfalfa mosaic virus (AMV) is a devastating plant pathogen with an extensive host range, yet effective control strategies remain limited. This study investigated the prophylactic efficacy and molecular mechanisms of two plant immune inducers, the Paecilomyces variotii extract DYDS and the antiviral agent Dufulin, against AMV infection in cowpea (Vigna unguiculata). Our results demonstrate that both agents possess potent antiviral activity, with inactivation, protective, and therapeutic efficacies all exceeding 21.00%. Notably, DYDS exhibited superior overall performance. RT-qPCR and immunofluorescence assays confirmed a significant downregulation of AMV coat protein (CP) expression in treated plants. Furthermore, exogenous application of these inducers mitigated chlorophyll loss and markedly augmented the activities of key defense enzymes’ activity, including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), polyphenol oxidase (PPO), and L-phenylalanine ammonia-lyase (PAL), peaking at 5 days post-inoculation. In silico molecular docking simulations further revealed that DYDS and Dufulin interact spontaneously with the AMV-CP, yielding binding free energies of −6.5 and −5.8 kcal/mol, respectively. Gene expression analysis indicated that these inducers trigger a robust immune response through the integrated activation of the salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) signaling pathways. Collectively, these findings suggest that DYDS and Dufulin provide a dual mode of action—direct viral inhibition and host immune priming—offering a promising and sustainable approach for the management of AMV in leguminous crops. Full article

Salinity is a major limiting factor for alfalfa production. This study analyzed the differential regulatory mechanisms of ZT1 and ZT2 under salt stress (100 and 200 mM) through physiological and biochemical responses, the photosynthetic system, and transcriptome and metabolome. The results show that ZT1 is more tolerant than ZT2. Under salt stress, root vitality (30.95–66.28%), shoot dry weight (13.23–53.01%), and chlorophyll a (20.00–50.00%) decreased significantly. However, Na⁺/K⁺ (0.93–3.62 times), MDA (0.19–2.52 times), and superoxide dismutase (28.94–79.56%) increased significantly. From a physiological perspective, ZT1 and ZT2 can endow plants with salt tolerance by regulating the Na⁺/K⁺ balance, inducing osmotic agents, enhancing antioxidant activity, and regulating the photosynthetic system. In omics analysis, there were significant differences in their regulation of the biosynthetic pathways of phenylpropanin and flavonoids. ZT1’s salt tolerance is strengthened by the positive regulation of transcription factors (GRAS) and genes (CHS, POD, CAD, F3H, and PAL), together with the accumulation of (-)-epicatechin, eriodictyol, and butein. In contrast, ZT2 responded positively to salt stress via the regulation of TFs (GRAS, TRAF, and bHLH) and genes (POD, C4H, CHS, and F3′5′H), as well as the accumulation of caffeic acid. The research results will provide new insights into alfalfa cultivation and new variety breeding in saline–alkali land. Full article

Background/Objectives: Salvia miltiorrhiza (Danshen) is a well-known medicinal herb in traditional Chinese medicine. It produces tanshinones and salvianolic acids as key bioactive constituents in its roots, yet the molecular basis for their tissue-specific accumulation is still poorly understood. This study aims to identify candidate functional genes involved in the biosynthesis of tanshinones and salvianolic acids, and to reveal the molecular basis underlying their tissue-specific accumulation in S. miltiorrhiza. Methods: For this purpose, we compared transcriptomic and metabolomic differences between the roots and leaves, and further measured a set of physiological parameters, including the POD, SOD, CAT and PAL activities, as well as the total phenols and flavones contents. Results: Metabolomic analysis identified 6805 metabolites, of which 241 were differentially accumulated between roots and leaves, with 172 upregulated in roots. The elevated metabolites included gibberellin, cryptotanshinone, decursinol angelate, chalcone, and psoralenol. Transcriptome analysis identified 32,700 annotated genes, with 9895 showing differential expression between roots and leaves, including 4199 upregulated in roots. Roots exhibited higher levels of phenols and flavones, as well as significantly greater POD, SOD, CAT, and PAL activities. Conclusions: Integrated omics analysis identified putative candidate genes including CPS, KS, and P450s as potential contributors for tanshinone and salvianolic acid biosynthesis. The identified genes provide valuable resources for molecular breeding, offering opportunities to improve the medicinal quality of S. miltiorrhiza. Full article

Background/Objectives: Older adults living in long-term care facilities (LTCFs) are at high risk of undernutrition. This study evaluated the adequacy of planned energy intake (PEI) by comparing prescribed diets with individual requirements measured using indirect calorimetry (IC) and by modelling how different levels of food consumption affect energy adequacy. Methods: In this cross-sectional study, 169 adults aged ≥ 65 years living in LTCFs underwent anthropometric assessment and IC-based measurement of resting energy expenditure. Total energy expenditure (TEE) was derived using activity-specific PAL factors. PEI was calculated from 7-day menu records (oral diets) or enteral feeding prescriptions. Scenario analyses assumed intake levels from 100% to 50% of PEI and applied BMI-specific adequacy thresholds. Results: Mean TEE was 1447 ± 359 kcal/day (25 ± 6 kcal/kg), whereas mean PEI was 1999 ± 400 kcal/day, yielding an average surplus of 552 ± 496 kcal/day and a TEE/PEI ratio of 0.76. PEI did not differ across sex, BMI, or activity groups despite significant differences in measured TEE. Individuals receiving enteral nutrition demonstrated close agreement between intake and expenditure. Fewer than half of residents consumed > 75% of their served portion, about one third consumed 51–75%, and approximately one fifth consumed ≤ 50%, based on caregiver reports. Scenario modelling showed that the proportion of adults meeting adequacy criteria remained relatively stable at intake levels of 100–70% of PEI but declined significantly below 70%. Conclusions: Planned dietary energy provision exceeded measured requirements, yet underweight remained frequent, indicating a gap between prescribed and consumed energy. Monitoring actual intake and adjusting provision to individual needs are essential in LTCFs. Full article