Search Results (169)

Fusarium wilt, caused by Fusarium oxysporum f. sp. phaseoli (Fop), is a major constraint to global common bean (Phaseolus vulgaris L.) production. Thiamine (vitamin B1), an essential coenzyme in plant metabolism, has recently emerged as a potential regulatory factor in plant defense. Here, we performed a comprehensive genome-wide analysis of thiamine biosynthesis-related genes in common bean and elucidated their roles in resistance to Fusarium wilt. Five key thiamine biosynthetic genes were identified and characterized, showing conserved functional domains and evolutionary conservation across species. Expression profiling revealed tissue-specific patterns, with PvTHI1-1 and PvTHIC being highly expressed in reproductive and photosynthetic organs, with their relative expression levels 0.28–0.57 higher than other members in the same tissue, while PvTPK maintained a basal expression level in the roots. Upon Fop infection, resistant genotypes exhibited significantly higher expression of thiamine biosynthetic genes and greater accumulation of endogenous thiamine and its derivatives than susceptible ones. Functional analysis using Agrobacterium rhizogenes-mediated transformation demonstrated that overexpression of PvTPK enhanced thiamine metabolism and conferred resistance in susceptible genotypes. Similarly, exogenous application of thiamine upregulated biosynthetic genes and improved disease resistance. Together, these results reveal that thiamine biosynthesis is intricately linked to Fusarium wilt resistance and that both genetic and biochemical manipulation of thiamine pathways can enhance disease tolerance. This study provides new insights into thiamine-mediated plant immunity and establishes a foundation for its application in the control of Fusarium wilt in common bean. Full article

Halophytes such as Salicornia europaea rely on biochemical and structural mechanisms to survive in saline environments. This study aimed to evaluate oxidative stress and structural defense responses in four inland populations—Poland (Inowrocław, Ciechocinek), Germany (Salzgraben-Salzdahlum, Salz), and Soltauquelle (Soltq)—subjected to 0, 200, 400, and 1000 mM NaCl, using non-destructive, image-based approaches. Lipid peroxidation was assessed via malondialdehyde (MDA) detected with Schiff’s reagent, and hydrogen peroxide (H₂O₂) accumulation was visualized with 3,3′-diaminobenzidine (DAB). Roots and shoots were analyzed through colour image analysis and quantified using a computer vision system (CVS). MDA accumulation revealed population-specific differences, with Salz tending to exhibit lower peroxidation, characterized by lower L* ≈ 42–43 and higher b* ≈ 37–18 in shoots at 200–400 mM, which may reflect a potentially more effective salt-management strategy. Although H₂O₂ responses deviated from a direct salinity-dependent trend, particularly in the tolerant Salz and Soltq populations, both approaches effectively tracked population-specific adaptation, with German populations displaying detectable basal H₂O₂ levels, consistent with its multifunctional signalling role in salt management and growth regulation. Structural defences were further explored through histochemical mapping and image analysis of pectin and lignin distribution, which revealed population-specific patterns consistent with cell wall remodelling under stress. Non-destructive, image-based methods proved effective for detecting oxidative and structural responses in halophytes. Such a non-destructive, cost-efficient, and reproducible approach can accelerate the identification of salt-tolerant ecotypes for saline agriculture and reinforce S. europaea as a model species for elucidating salt-tolerance mechanisms. Full article

The Northeast region in China is a major maize-producing area; however, low-temperature stress (TS) limits maize (Zea mays L.) seed germination, affecting population establishment and yield. In order to systematically explore the regulation mechanism of maize radicle which is highly sensitive to low-temperature environment response to TS, seeds of ZD958 and DMY1 were used to investigate germination responses under 15 °C (control) and 5 °C (TS) conditions. Phenotypic, physiological, transcriptomic, and metabolomic analyses were conducted on the radicles after 48 h of TS treatment. TS caused reactive oxygen species (ROS) imbalance and oxidative damage in radicle cells, inhibiting growth and triggering antioxidant defenses. Integrated transcriptomic and metabolomic analyses revealed that flavonoid metabolism may play a pivotal role in radicle responses to TS. Compared with the control treatment, ZD958 and DMY1 under TS treatment significantly increased (p < 0.01) the total flavonoid content, total antioxidant capacity, 4-coumarate-CoA ligase activity, and dihydroflavonol 4-reductase activity by 15.99% and 16.01%, 18.41% and 18.54%, 63.54% and 31.16%, and 5.09% and 7.68%, respectively. Despite genotypic differences, both followed a shared regulatory logic of “low-temperature signal-driven—antioxidant redirection—functional synergy.” This enabled ROS scavenging, redox balance, and antioxidant barrier formation, ensuring basal metabolism and radicle development. Full article

In the light reactions of photosynthesis, reactive oxygen species (ROS), such as superoxide anion radical (O₂^•−), hydrogen peroxide (H₂O₂), singlet oxygen (¹O₂*), and hydroxyl radical (OH^•), are continuously generated at basal levels and are kept in homeostasis by the antioxidative enzymatic and non-enzymatic systems. Nevertheless, under abiotic or biotic stress conditions, this balance between the creation and elimination of ROS is disrupted, and the increased ROS production leads to oxidative stress, which is involved in the growth retardation of plants. However, ROS are also beneficial, since they trigger the plant’s defense mechanisms for handling oxidative stress and are fundamental signaling molecules for the regulation of a range of physiological functions under optimum growth conditions or environmental stress circumstances, activating a plethora of acclimation responses. Gaining insight into the relationship between ROS generation, ROS scavenging, and the protective role of ROS will contribute to improving agricultural sustainability in the face of global climate change. Full article

This study evaluates the impact of biotic elicitors and hormone regimes on the in vitro establishment, shoot multiplication, and organogenesis of Solanum tuberosum L. cv. Fianna under controlled laboratory conditions. Explants derived from pre-treated tubers were cultured on Murashige and Skoog (MS) medium supplemented with vitamins and varying concentrations of growth regulators or elicitors. Aseptic establishment achieved a high success rate (~95%) using a 6% sodium hypochlorite disinfection protocol. Multiplication was significantly enhanced with a combination of 0.2 mg L⁻¹ naphthaleneacetic acid (NAA) and 0.5–1.0 mg L⁻¹ benzylaminopurine (BAP), producing the greatest number and length of shoots and roots. Direct organogenesis was stimulated by bio-elicitors Activane^®, Micobiol^®, and Stemicol^® in (MS) basal medium at mid-level concentrations (0.5 g or mL L⁻¹), improving shoot number, elongation, and root development. Activane^®, Micobiol^®, and Stemicol^® are commercial elicitors that stimulate plant defense pathways and morphogenesis through salicylic acid, microbial, and jasmonic acid signaling mechanisms, respectively. Indirect organogenesis showed significantly higher callus proliferation in Stemicol^® and Micobiol^® treatments compared to the control medium, resulting in the highest fresh weight, diameter, and friability of callus. The results demonstrate the potential of biotic elicitors as alternatives or enhancers to traditional plant growth regulators in potato tissue culture, supporting more efficient and cost-effective micropropagation strategies. Full article

Plant cell wall-derived oligosaccharides, such as xylo-oligosaccharides (XOS), serve as key signaling molecules regulating plant growth and immunity. The bioactivity of XOS is closely tied to their degree of polymerization (DP), yet the molecular mechanisms underlying DP-specific effects remain poorly understood. Here, we investigated the transcriptional and phenotypic responses of lettuce (Lactuca sativa) to foliar application of four high-purity XOS variants: xylobiose (XOSY, DP2), xylotriose (XOSB, DP3), xylotetraose (XOSD, DP4), and xylopentose (XOSW, DP5). Phenotypic analyses revealed that high-DP XOS (XOSD and XOSW) significantly enhanced aboveground biomass and root system development, with XOSD showing the most pronounced effects, including a 31.74% increase in leaf area and a 20.71% increase in aboveground biomass. Transcriptomic profiling identified extensive transcriptional reprogramming across treatments, with XOSD eliciting the highest number of differentially expressed genes (DEGs). Functional enrichment analyses indicated that XOSD and XOSW upregulated genes involved in plant hormone signaling, starch and sucrose metabolism, and cell wall biosynthesis, while downregulating photosynthesis-related genes. Notably, MapMan and KEGG pathway analyses revealed that XOSD significantly activated biotic stress-related pathways, including MAPK signaling, β-1,3-glucanase activity, and PR protein pathways. In contrast, XOSY treatment primarily upregulated genes linked to basal immunity, highlighting distinct mechanisms employed by low- and high-DP XOS. These findings demonstrate that XOS with varying DP differentially modulate growth- and immunity-related processes in lettuce. High-DP XOS, particularly XOSD, not only promote plant biomass accumulation but also enhance immune responses, highlighting their potential as biostimulants for sustainable agriculture. This study provides a molecular framework for understanding the DP-specific bioactivity of XOS and their dual role in optimizing plant growth and defense. Full article

Retinal Pigment Epithelium (RPE), a component of the blood–retinal barrier, plays a pivotal role in maintaining retinal homeostasis and visual function. Dysfunction of the RPE is an early event that triggers photoreceptor death, in Age-related Macular Degeneration (AMD), a multifactorial disorder primarily caused by an imbalance between endogenous antioxidant defenses and reactive oxygen species production. Our in vitro study investigated the hormetic effects of curcumin in human RPE cells (ARPE-19), focusing on its capability to modulate two enzymes related to the onset of AMD: Sirtuin 1 (SIRT1), a NAD+-dependent deacetylase enzyme involved in cellular metabolism, aging, and stress response, and caspase-3, a crucial enzyme in programmed cell death. Curcumin exhibited classic hormetic doseresponses, with low concentrations (5–10 μM) providing cytoprotection while at high doses (≥20 μM) inducing toxicity. Under moderate oxidative stress, acetylated p53 was significantly reduced, indicating SIRT1 activation; curcumin 10 μM restored basal SIRT1 activity, while 5 µM did not. Both concentrations significantly decreased cleaved caspase-3 levels, demonstrating the anti-apoptotic effects of curcumin. Our results reveal curcumin’s hormetic mechanisms of RPE protection and emphasize the critical importance of dose optimization within the hormetic window for AMD therapeutic development. Full article

L-carnitine supplementation enhances fatty acid oxidation and antioxidant defense mechanisms in livestock. Twenty-four wether lambs were randomly assigned to one of three dietary treatments: a control (basal diet), a low-L-carnitine diet (0.01%), or a high-L-carnitine diet (0.05%). After a 15-day adaptation period, all lambs underwent a 45-day experimental phase to assess the impact of L-carnitine supplementation on performance, carcass, muscle, and antioxidant capacity. Although growth performance did not show significant differences (p > 0.05), muscle pH increased in the L-carnitine group (p < 0.05), while drip loss decreased in both the low- and high-dose groups (p < 0.05). The a* value of the Longissimus dorsi muscle significantly increased (p < 0.01), enhancing meat color saturation (p < 0.05), with a reduction in the hue angle observed in the high-dose group (p < 0.01). L-carnitine supplementation led to an elevated myoglobin content and a higher proportion of oxymyoglobin, driven by a significant increase in MRA activity (p < 0.01). The concentration of L-carnitine was positively correlated with the a* value, which in turn was associated with higher total myoglobin content and a greater proportion of oxymyoglobin. In terms of antioxidant capacity, the L-carnitine group exhibited a significant increase in superoxide dismutase content. Moreover, there was upregulation of TFR1 and CAT expression at the mRNA level, while HEPH showed downregulation (p < 0.01). Significant increases were observed in both content and mRNA expression of LDHB and NADHBR5 (p < 0.01). The addition of 0.05% L-carnitine to the diet significantly enhanced muscle color stability in hybrid sheep. This improvement was primarily driven by a significant increase in MRA activity in the high-dose group, which facilitated the conversion of metmyoglobin to oxymyoglobin, thereby significantly boosting meat quality prospects for the sheep industry. Full article

The AP2/ERF transcription factor family plays pivotal roles in plant growth, stress responses, and defense mechanisms, yet its diversity in camphor trees remains underexplored. This study identified 154 AP2/ERF genes in the Camphora officinarum genome, with over 80% belonging to the ERF subfamily, a distribution consistent with other angiosperms. Synteny analysis revealed that tandem and segmental duplications were key drivers of family expansion, suggesting adaptive diversification under ecological pressures. Structural analysis showed that the majority of ERF/RAV subfamily genes possess a single-exon structure, whereas AP2 subfamily genes display muti-exon structures, indicating divergent evolutionary trajectories and potential functional versatility via alternative splicing. Promoter analyses detected numerous hormone- and stress-responsive elements, linking these genes to abscisic acid, auxin, gibberellin signaling, and pathogen defense. Further expression profiling during stem development showed that approximately 60% of CoAP2/ERF genes were constitutively expressed across 17 expression trends, suggesting roles in basal development and stage-specific processes (e.g., lignification). Under Epicoccum poaceicola infection, 23 CoAP2/ERF genes were differentially expressed. Among them, upregulated ERF homologs related to RAP2.2/2.3 suggested roles in hypoxia and antimicrobial responses, while downregulation of ERF5 homologs indicated a growth–defense trade-off, whereby developmental processes are suppressed to prioritize pathogen resistance. Overall, this study deciphers the genomic architecture and structural diversity of CoAP2/ERF genes, along with expression dynamics of these genes in development and biotic stress adaptation of camphor trees. These findings provide critical insights into transcriptional regulation of development and stress responses in camphor trees and establish a theoretical basis for molecular breeding and biotechnological strategies aimed at improving stress resilience in woody plants. Full article

Hemopexin (HPX) is a heme-binding glycoprotein involved in detoxification, oxidative stress regulation, and immune defense. In teleosts, gene duplication gave rise to Wap65-1 and Wap65-2, but the structure and function of ancestral HPX in basal actinopterygians remain poorly understood. Here, we characterized HPX from the Siberian sturgeon (Acipenser baerii), a slow-evolving chondrostean species that diverged prior to the teleost-specific duplication. Structural modeling and superimposed 3D alignment revealed high similarity between sturgeon HPX, human HPX, and Wap65-2, but not Wap65-1. Phylogenetic analysis placed sturgeon HPX in a distinct basal clade within the Actinopterygian lineage, positioned below the divergence of Wap65 paralogs. Tissue expression was liver-dominant but also evident in skin and kidney, and HPX transcripts increased during larval development. Under Aeromonas hydrophila challenge, HPX was strongly upregulated in immune-relevant tissues. Thermal challenge also induced modest, tissue-specific changes, particularly in peripheral tissues. These results indicate that ancestral HPX possessed multivalent stress responsiveness—primarily immune-related—with supplementary thermal sensitivity. The observed functional flexibility is consistent with the hypothesis that ancestral HPX functions were partitioned following Wap65 gene duplication in teleosts, with Wap65-1 evolving toward a specialized thermal response role. Full article

Fusarium head blight (FHB) is a major threat to wheat production that is caused by toxigenic species of the Fusarium graminearum complex. This study aimed to investigate the biochemical and molecular defense responses of Brazilian wheat genotypes (BRS 194, BRS Parrudo, and Frontana) with contrasting FHB susceptibilities following inoculation with F. graminearum (deoxynivalenol producer) and F. meridionale (nivalenol producer). Temporal patterns of antioxidant enzymes, defense-related enzymes, and gene expression (ABC-Transporter and Ca²⁺-ATPase) were analyzed from 12 to 96 h after inoculation. The ANOVA results revealed significant effects of genotypes, inoculation, and time after inoculation on most of the evaluated enzymatic activities. Frontana exhibited high basal activity for most enzymes, and after inoculation, the enzyme activity was higher than in other genotypes. BRS 194 presented delayed and fragmented activation patterns, particularly under DON-producing pathogen infection. According to the transcriptome results, inoculation with the NIV-producing pathogen upregulated both genes, reaching up to an 18-fold increase. BRS 194 showed an upregulated transcript pattern from the early hours after inoculation. Frontana showed increased transcript levels, reaching 12-fold, under DON-producing pathogen infection. These findings show that biochemical and molecular responses varied depending on genotype and the chemotype of the Fusarium isolate, highlighting the importance of early, coordinated defense activation in FHB resistance. Full article

Based on the limited hepatic hydroxylation efficiency of dietary VD3 in teleosts and the superior bioavailability of its metabolite, 25(OH)D3, this study investigated the regulatory mechanisms of dietary 25(OH)D3 supplementation in yellow catfish—an economically significant species lacking prior nutritional data on this metabolite. A total of 360 fish were divided into three groups—control (basal diet), VD3 (2500 IU/kg VD3), and 25(OH)D3 (2500 IU/kg 25(OH)D3)—and fed for 8 weeks. Compared to the control, both supplemented groups showed elevated superoxide dismutase (SOD), total antioxidant capacity (T-AOC), catalase (CAT), and transforming growth factor-β (TGF-β) activities, alongside reduced malondialdehyde (MDA), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) levels. The 25(OH)D3 group exhibited higher T-AOC and CAT activities and lower TNF-α than the VD3 group. Metabolomic and transcriptomic analyses identified 65 differentially expressed metabolites (DEMs) and 3515 differentially expressed genes (DEGs). Enrichment analysis indicated that the DEMs (e.g., indole compounds, organic acids, aldosterone, L-kynurenine) and DEGs (pgd, mthfr, nsdhl, nox5, prdx2, mpx, itih2, itih3, eprs1) that were highly and significantly expressed in the 25(OH)D3 group were primarily associated with antioxidant defense and inflammatory responses. Dietary 25(OH)D3 was more effective than VD3 in promoting antioxidant capacity and modulating inflammation in yellow catfish. Full article

Asian chestnut gall wasp (ACGW) (Dryocosmus kuriphilus Yasumatsu), native to China, is an invasive pest that causes significant economic losses in Castanea species. While some cultivars show full resistance by inhibiting insect development in buds, the underlying defense mechanisms remain unclear. In this study, the accumulation and distribution of hydrogen peroxide (H₂O₂) were investigated in dormant buds of chestnut cultivars that are resistant and susceptible to D. kuriphilus by using the 3,3′-diaminobenzidine (DAB) staining method. Buds were examined under a stereomicroscope during key stages of pest development, including oviposition, transition from egg to larva, gall induction, and gall development. Baseline levels of H₂O₂ were detected in all buds; however, these levels varied among cultivars, with resistant cultivars exhibiting lower basal levels. The degree of H₂O₂ accumulation was found to vary depending on plant–insect interaction, physiological processes, and cultivar-specific traits. Histochemical staining revealed that brown spots indicative of H₂O₂ accumulation were concentrated in the vascular bundles of leaf primordia and in the apical regions. In resistant hybrid cultivars, the defense response was activated at an earlier stage, while in resistant Castanea sativa Mill. cultivars, the response was delayed but more robust. Although consistently high levels of H₂O₂ were observed throughout the pest interaction in susceptible cultivars, gall development was not inhibited. During the onset of physiological bud break, increased H₂O₂ accumulation was observed across all cultivars. This increase was associated with endodormancy in susceptible cultivars and with both defense mechanisms and endodormancy processes in resistant cultivars. These findings highlight the significant role of H₂O₂ in plant defense responses, while also supporting its function as a multifunctional signaling molecule involved in gall development and the regulation of physiological processes. Full article

The crucial roles of the lipase-like protein enhanced disease susceptibility 1 (EDS1) and phytoalexin deficient 4 (PAD4) in disease resistance in Arabidopsis have been identified. However, their function in rice (Oryza sativa L.) resistance to brown planthopper (BPH, Nilaparvata lugens Stål), the most notorious pest of rice, remains unknown. In this study, the transcript levels of OsEDS1 and OsPAD4 were rapidly altered by BPH infestation. Mutation in either OsPAD4 or OsEDS1 resulted in increased rice susceptibility to BPH, which was associated with increased honeydew excretion and an increased host preference of BPH. Furthermore, mutation in either OsPAD4 or OsEDS1 led to decreased basal levels of salicylic acid (SA) and jasmonic acid (JA) in the absence of BPH, along with the depressed expression of the defense-responsive genes OsPAL, OsICS1, OsPR1a, OsLOX1, OsAOS1 and OsJAZ11 involved in SA and JA biosynthesis and signaling. The BPH infestation-mediated elevation of SA levels and the expression of SA biosynthesis and signaling genes was dampened in eds1 and pad4 plants, whereas BPH infestation-mediated depressions of JA levels and the expression of JA biosynthesis and signaling genes were reversed in eds1 and pad4 plants. Taken together, our findings indicated that both OsPAD4 and OsEDS1 positively regulate rice resistance to BPH. Full article

This study investigated the effects of fermented Chinese herb (FCH) on the growth indices, leukocyte activity, and biochemical indices of carp (Cyprinus carpio). Astragalus membranaceus (AM), Pericarpium Citri Reticulatae (PCR), and Glycyrrhizae Radix et Rhizoma (GRR) as feed additives enhance immune function, promote growth, and exert anti-inflammatory effects, respectively. Therefore, this study investigated the effects of co-fermented blends of these three herbs on growth performance and related parameters in common carp. By adding 2%, 5%, and 10% of the FCH to co-incubate with carp leukocytes, the results show that all three experimental treatments could enhance the respiratory burst activity and phagocytic activity of carp leukocytes. After 28 days of feeding with basal feed supplemented with 2%, 5%, and 10% (w/v) of the FCH, the weight gain rate and specific growth rate of carp were significantly higher than those of the control treatment without additives (ANOVA, p < 0.05), with the 5% treatment showing the highest. The activities of intestinal digestive enzymes were significantly increased (ANOVA, p < 0.05). On the 21st day, the activities of amylase (AMS), lipase (LPS), and chymotrypsin were increased compared to the control treatment. The 5% and 10% treatments showed significantly higher intestinal digestive enzyme activities compared to the 2% treatment. The serum superoxide dismutase (SOD) levels in both the control and experimental treatments initially increased and then decreased, with all three experimental treatments having higher levels than the control treatment. The activities of liver glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) in the experimental treatments showed no significant changes compared to the control treatment (ANOVA, p > 0.05). However, the serum GPT activity in the 5% treatment was significantly lower than that of the control treatment (ANOVA, p < 0.05), while no significant differences were observed in the other treatments. The results indicate that adding 2~10% of FCH to carp feed can improve intestinal digestion, enhance phagocytic activity and the body’s antioxidant defense capabilities, and effectively promote the growth of carp. It can significantly improve farming efficiency and economic benefits, reduce dependence on chemical drugs, and lower environmental pollution, showing good application prospects in production. Full article