Search Results (635)

Oxybenzone (OBZ), an organic ultraviolet filter, is an emerging contaminant posing severe threats to ecosystem health. Using tobacco (Nicotiana tabacum) as a model plant, this study investigated the alleviation mechanisms of exogenous silicon (Na₂SiO₃, Si) and bamboo-based biochar (Bc) under OBZ stress. We systematically analyzed physiological and biochemical responses, including phenotypic parameters, reactive oxygen species metabolism, photosynthetic function, chlorophyll synthesis, and endogenous hormone levels. Results reveal that OBZ significantly inhibited tobacco growth and triggered a reactive oxygen species (ROS) burst. Additionally, OBZ disrupted antioxidant enzyme activities and hormonal balance. Exogenous Bc mitigated OBZ toxicity by adsorbing OBZ, directly scavenging ROS, and restoring the ascorbate-glutathione (AsA-GSH) cycle, thereby enhancing photosynthetic efficiency, while Si alleviated stress via cell wall silicification, preferential regulation of root development and hormonal signaling, and repair of chlorophyll biosynthesis precursor metabolism and PSII function. The mechanisms of the two stress mitigators were complementary, Bc primarily relied on physical adsorption and ROS scavenging, whereas Si emphasized metabolic regulation and structural reinforcement. These findings provide practical strategies for simultaneously mitigating organic UV filter pollution and enhancing plant resilience in contaminated soils. Full article

Barley leaf stripe, caused by Pyrenophora graminea (Pg), significantly reduces yields across various regions globally. Understanding the resistance mechanisms of barley to Pg is crucial for advancing disease resistance breeding efforts. In this study, two barley genotypes—highly susceptible Alexis and immune Ganpi2—were inoculated with the highly pathogenic Pg isolate QWC for 7, 14, and 18 days. The number of differentially expressed genes (DEGs) in Alexis was 1350, 1898, and 2055 at 7, 14, and 18 days, respectively, while Ganpi2 exhibited 1195, 1682, and 2225 DEGs at the same time points. Gene expression pattern analysis revealed that Alexis responded more slowly to Pg infection compared to Ganpi2. A comparative analysis identified 457 DEGs associated with Ganpi2’s immunity to Pg. Functional enrichment of these DEGs highlighted the involvement of genes related to plant-pathogen interactions and kinase activity in Pg immunity. Additionally, 20 resistance genes and 24 transcription factor genes were predicted from the 457 DEGs. Twelve candidate genes were selected for qRT-PCR verification, and the results showed that the transcriptomic data was reliable. We conducted cloning of the candidate Pg resistance gene HvLRR_8-1 by the barley cultivar Ganpi2, and the sequence analysis confirmed that the HvLRR_8-1 gene contains seven leucine-rich repeat (LRR) domains and an S_TKc domain. Subcellular localization in tobacco indicates that the HvLRR_8-1 is localized on the cell membrane. Through the functional analysis using virus-induced gene silencing, it was demonstrated that HvLRR_8-1 plays a critical role in regulating barley resistance to Pg. This study represents the first comparative transcriptome analysis of barley varieties with differing responses to Pg infection, providing that HvLRR_8-1 represents a promising candidate gene for improving durable resistance against Pg in cultivated barley. Full article

Tobacco use disorder remains a leading cause of preventable mortality, with nicotine playing a central role in the development and maintenance of dependence, mainly through its action on α4β2 nicotinic acetylcholine receptors (nAChRs). Smoking cessation treatments must address both physiological withdrawal and the affective disturbances (such as anxiety, irritability, and mood lability) which often facilitate relapses. This review compares two pharmacotherapies used in smoking cessation, varenicline and cytisinicline (cytisine), with particular focus on their impact on emotional regulation, psychological symptoms, and neuropsychiatric safety. Varenicline, a high-affinity partial agonist at α4β2 nAChRs, has demonstrated superior efficacy in maintaining abstinence and is well-supported by robust clinical data, including in psychiatric populations. However, its use may be limited by adverse effects such as nausea and sleep disorders. Cytisinicline, a structurally similar but less potent partial agonist, has recently gained renewed interest due to its lower cost, favorable tolerability profile, and comparable effectiveness in the general population. Although less extensively studied in patients with serious mental illness, preliminary data suggest cytisinicline may offer a better side effect profile, particularly regarding sleep disturbances and emotional reactivity. Both agents appear to ameliorate withdrawal-related affective symptoms without significantly increasing psychiatric risk. Ultimately, pharmacotherapy choice should be guided by individual clinical features, mental health status, treatment tolerability, and resource availability. Further research is needed to establish cytisinicline’s efficacy and safety across diverse clinical contexts, particularly among individuals with severe psychiatric comorbidities. Full article

Fe deficiency in apple trees can lead to leaf chlorosis and impede root development, resulting in significant alterations in signaling, metabolism, and genetic functions, which severely restricts fruit yield and quality. It is well established that WRKY transcription factors (TFs) are of vital significance in mediating plant responses to abiotic stress. Real-time quantitative fluorescence (RT-qPCR) analysis displayed that Fe deficiency stress can significantly induce WRKY69 TF gene expression. However, the potential mechanisms by which the WRKY69 gene involved in Fe deficiency stress remains to be investigated. To address this limitations, the WRKY69 gene (MD09G1235100) was successfully isolated from apple rootstock Malus halliana and performed both homologous and heterologous expression analyses in apple calli and tobacco to elucidate its functional role in response to Fe deficiency stress. The findings indicated that transgenic tobacco plants exhibited enhanced growth vigor and reduced chlorosis when subjected to Fe deficiency stress compared to the wild type (WT). Additionally, the apple calli that were overexpressed WRKY69 also exhibited superior growth and quality. Furthermore, the overexpression of the WRKY69 gene enhanced the ability of tobacco to Fe deficiency stress tolerance by stimulating the synthesis of photosynthetic pigments, increasing antioxidant enzyme activity, and facilitating Fe reduction. Additionally, it increased the resistance of apple calli to Fe deficiency stress by enhancing Fe reduction and elevating the activity of antioxidant enzymes. For example, under Fe deficiency stress, the proline (Pro) contents of the overexpression lines (OE-2, OE-5, OE-6) were 26.18 mg·g⁻¹, 26.13 mg·g⁻¹, and 26.27 mg·g⁻¹, respectively, which were 16.98%, 16.76%, and 17.38% higher than the proline content of 22.38 mg·g⁻¹ in the wild-type lines, respectively. To summarize, a functional analysis of tobacco plants and apple calli displayed that WRKY69 TF serves as a positive regulator under Fe deficiency stress, which provides candidate genetic resources for cultivating apple rootstocks or varieties with strong stress (Fe deficiency) resistance. Full article

Once marketed as smoking cessation tools, e-cigarettes are used by adolescents mainly for entertainment, driven by aggressive marketing, appealing flavors, and safer alternatives to smoking. This study analyzes data from the National Youth Tobacco Survey (NYTS) to explore trends in adolescent perceptions and usage patterns of e-cigarettes from 2011 to 2023, focusing on their dual roles as cessation aids and recreational products. Cross-sectional data from the NYTS over four years (2011: N = 18,866; 2015: N = 17,711; 2019: N = 19,018; 2023: N = 22,069) formed the foundation of this study. This study investigated demographic trends, usage frequency, initial and future use patterns, and quitting behavior. Descriptive statistics and latent class analysis (LCA) were employed to examine adolescent e-cigarette use patterns, with statistical significance determined at p < 0.05. The reasons for using e-cigarettes have changed significantly over the years because of family or friends. In all years (2015–2023), use for smoking cessation dropped significantly (2.33% in 2023 vs. 6.95% in 2015). In 2023, 38% wanted to quit using e-cigarettes within 30 days, and 25% attempted to quit at least 10 times. Flavored e-cigarette users were more than twice as likely to consider quitting compared to those not interested in flavors (OR = 2.64). Our findings highlight a significant decrease in the use of e-cigarettes for cessation, with a corresponding increase in recreational use over time. These trends emphasize the urgency of implementing interventions to mitigate nicotine addiction and its associated health risks among adolescents. Adolescent e-cigarette use has transitioned from being primarily driven by cessation efforts to recreational purposes, largely influenced by appealing flavors and social factors such as peer influence, showing the need for stricter marketing regulations and targeted educational campaigns. Full article

Hemerocallis spp. exhibit distinct flower opening times, categorized into nocturnal and diurnal types. Previous studies have demonstrated that the circadian clock and CONSTANS (CO) genes play crucial roles in regulating flowering in Hemerocallis. However, the key genes that integrate flowering pathways remain largely unknown. To address this gap, we identified potential homologs of the FLOWERING LOCUS T (FT) gene in Hemerocallis. A yeast one-hybrid assay revealed that HfCOL2 and HfLHY directly bind to the HfFT1 and HfFT2 promoters, thereby activating FT transcription. The expression analysis reveals that HfCOL2 expression rhythms not only display opposing patterns between nocturnal and diurnal opening types of Hemerocallis but also between leaf and flower tissues. The peak expression of HfCOL2 in flowers aligns closely with the respective opening times of diurnally and nocturnally flowering Hemerocallis. The overexpression of HfCOL2 in tobacco plants led to early flowering and prolonged flower longevity. In Hemerocallis, the HfCOL2 gene plays a pivotal role not only in photoperiod-induced flowering but also in the circadian rhythm-mediated regulation of flower opening time. Due to the limited availability of plant materials exhibiting distinct flower opening rhythms, research in this area has been constrained. Identifying the key genes in the flowering pathway of Hemerocallis can facilitate a better understanding of the mechanisms by which plants respond to circadian rhythms. Full article

Soil salinization threatens agriculture by inducing osmotic stress, ion toxicity, and oxidative damage. SnRK2 genes are involved in plant stress responses, but their roles in salt stress response regulation of tobacco remain unclear. Through genome-wide analysis, we identified 54 SnRK2 genes across four Nicotiana species (N. tabacum, N. benthamiana, N. sylvestris, and N. tomentosiformis). Phylogenetic reconstruction clustered these genes into five divergent groups, revealing lineage-specific expansion in diploid progenitors (N. tomentosiformis) versus polyploidy-driven gene loss in N. tabacum. In silico promoter analysis uncovered regulatory networks involving light, hormones, stress, and developmental signals, with prevalent ABA-responsive elements (ABREs) supporting conserved stress-adaptive roles. Structural analysis highlighted functional diversification through variations in intron–exon architecture and conserved kinase motifs. This study provides a genomic atlas of SnRK2 evolution in Nicotiana, offering a foundation for engineering salt-tolerant crops. Full article

Phase-separated membraneless biomolecular condensates in the cytoplasm and nucleus are now recognized to play a major role in modulating diverse functions in mammalian cells, and contribute to cancer pathogenesis through dysregulated function of condensates of transcription factors such as STAT3 and fusion oncoproteins. Oral cancer, the sixth most prevalent malignancy worldwide, in the absence of overt causes such as tobacco or alcohol, most frequently occurs in a U-shaped zone (floor of mouth, side of tongue, anterior fauces and retromolar region) reflecting the path of liquid transit through the mouth. The cellular basis for this “high-risk” zone and the biochemical mechanisms used by oral cells to combat repetitive tonicity and temperature stresses are incompletely understood. We had previously observed that at 37 °C, in OECM1 oral carcinoma cells, cytoplasmic condensates of antiviral human GFP-MxA GTPase disassembled within 1–2 min of exposure of cells to saliva-like one-third hypotonicity, and underwent “spontaneous” reassembly in the next 5–7 min. Moreover, hypotonic beverages (water, tea, coffee), investigated at 37 °C, triggered this condensate cycling. In the present studies we investigated whether this process was temperature sensitive, representative of cold vs. warm drinks. We observed a slowing of this cycle at 5 °C, and speeding up at 50 °C. The involvement in this disassembly/reassembly process of WNK-SPAK/OSR1 serine-threonine kinase pathway, best studied for regulation of water and Na, K and Cl influx and efflux in kidney tubule cells, was evaluated by us in oral cells using pathway inhibitors WNK463, WNK-IN-11 and closantel. The pan-WNK inhibitor WNK463 inhibited hypotonicity-driven condensate disassembly, while the SPAK/OSR1 inhibitor closantel markedly slowed reassembly. Unexpectedly, the WNK1-selective inhibitor (WNK-IN-11), triggered a dramatic and rapid (within 1 h) spheroid to fibril transition of GFP-MxA condensates in live cells, but without affecting MxA antiviral function. The new data suggest a novel hypothesis for the anatomic localization of oral cancer in the U-shaped “high-risk” zone in the mouth: dysfunction of biomolecular condensates in oral cells along the beverage transit pathway through the mouth due to repetitive tonicity and temperature stresses that might underlie a prooncogenic progression. Full article

Phalaenopsis pulcherrima are known for their captivating floral morphology and diverse colors, demonstrate exceptional resilience to adverse environmental conditions, and exhibit significant potential for hybrid breeding. However, current research on flower coloration is still limited. The data from this study indicates that variations in anthocyanin levels are the primary determinants of the difference between white and purple colors. Through RNA-seq, we identified 469 genes that were differentially expressed. Furthermore, our bioinformatics exploration uncovered two potential transcription factors, PpMYB1 and PpbHLH1, which play regulatory roles in anthocyanin accumulation. Y2H assays demonstrated that these two TFs could form heterodimers and interact with each other. Afterwards, transient expression assays were conducted for the first time in P. pulcherrima flowers, revealing that overexpression of PpMYB1 alone or in combination with PpbHLH1 resulted in purple petal pigmentation. Overexpressing PpMYB1 in tobacco resulted in more purple-colored corollas, stamens, pistils, and pods compared to control plants. Y1H and dual-luciferase assays provided further evidence that PpMYB1 and PpbHLH1 interact with the promoters of the structural genes PpF3H, PpDFR, and PpANS in the anthocyanin biosynthesis pathway, thereby driving their robust expression. This study not only enhances our understanding of the molecular mechanisms underlying anthocyanin synthesis but also holds significant practical implications for advancing plant hybrid breeding and genetic engineering applications in flower color regulation. Full article

Sucrose phosphate synthase (SPS) is a rate-limiting enzyme in plant sucrose biosynthesis. However, the SPS gene family in luffa remains unidentified, and its functional involvement in sugar metabolism is unexplored. Here, we present the first genome-wide identification and functional analysis of the LaSPSs in luffa. We identified nine LaSPS genes, characterized their physicochemical and evolutionary properties, and analyzed their expression patterns in different tissues and response to ethylene and drought treatments. Nine tandem-duplicated LaSPS genes formed four clusters (T1(1/2), T2(3/4), T3(5/6), T4(7–9)) with conserved architectures. RNA-seq analysis indicated a ubiquitous downregulation of LaSPS genes in senescing luffa, wherein sucrose content correlated significantly with all LaSPS members except LaSPS1/2. Exogenous ethylene substantially repressed LaSPSs transcription, while 1-methylcyclopropene (1-MCP) treatment showed induction. Notably, LaSPS3/4 displayed high activation under drought stress. Functional validation via heterologous expression in tobacco confirmed that LaSPS3/4 positively regulates drought resistance. In summary, this study provides a novel perspective for the in-depth investigation of the molecular evolutionary mechanism of the LaSPS gene family and its biological functions in luffa. Full article

Luffa (Luffa acutangula) serves as an important edible, medicinal, and industrial crop. Sucrose synthase (SUS, EC 2.4.1.13) catalyzes sucrose metabolism and facilitates the entry of photosynthetically derived sucrose into metabolic pathways, playing crucial roles in plant growth, development, and stress responses. However, systematic investigations on the SUS gene family in luffa remain relatively scarce. In this study, we identified nine LaSUS family members distributed unevenly across six chromosomes. Their physicochemical properties and evolutionary relationships were systematically elucidated using bioinformatics tools. RNA-seq analysis revealed distinct expression patterns of LaSUS genes during luffa fruit aging, with most genes showing significant down-regulation during this process. Notably, several genes exhibited significant correlations with sucrose content during fruit aging. RT-qPCR analysis demonstrated the drought stress responsiveness of LaSUS genes, with LaSUS1 showing marked up-regulation under drought conditions. Furthermore, overexpression experiments in tobacco confirmed that LaSUS1 contributed to sugar accumulation, increased antioxidant enzyme activities, and positively regulated drought tolerance in luffa. This comprehensive study not only characterizes the LaSUS gene family and bridges the research gap of SUS genes in luffa but also provides theoretical support for investigating the roles of SUS genes in fruit ripening and abiotic stress responses in luffa. Full article

Apple (Malus domestica Borkh.) is an economically important fruit. The use of nitrate by plants plays a crucial role in their growth and development, and its absorption and dispersal are controlled by nitrate transport proteins (NRTs). In this study, we investigated the potential function of MdNRT2.4 under low-nitrogen (N) stress by overexpressing it in tobacco. Compared with plants treated with a normal nitrogen level (5 mM), the MdNRT2.4 overexpression lines under low-N stress (0.25 mM) exhibited significantly greater plant height and width, as well as larger leaves and a higher leaf density, than wild-type plants, suggesting that the overexpression of MdNRT2.4 enhances the low-N tolerance of tobacco. Enhanced antioxidant enzyme activities in the MdNRT2.4 overexpression plant lines promoted the scavenging of reactive oxygen species, which reduced damage to their cell membranes. GUS staining of pMdNRT2.4::GUS-transformed Arabidopsis thaliana lines showed that MdNRT2.4 was expressed in the roots, vascular bundles, seeds in fruit pods, and young anther sites, suggesting that MdNRT2.4 mediates the transport of nitrate to these tissues, indicating that MdNRT2.4 might promote nitrate utilization in apple and improve its tolerance to low-N stress. Experiments using yeast one-hybrid and dual-luciferase assays revealed that MdbHLH3 binds to the MdNRT2.4 promoter and activates its expression. MdbHLH3 belongs to the basic helix–loop–helix (bHLH) transcription factor (TF). It is speculated that MdbHLH3 may interact with the promoter of MdNRT2.4 to regulate N metabolism in plants and enhance their low-N tolerance. This study establishes a theoretical framework for investigating the regulatory mechanisms of low-N responsive molecules in apple, while simultaneously providing valuable genetic resources for molecular breeding programs targeting low-N tolerance. Full article

The CorA/MRS2-type transporters represent a crucial family of magnesium ion transporters widely distributed in plants. Through comprehensive screening and alignment using the Phytozome database, we identified seven magnesium-related MdMRS2 Confirm the deletion of the “Chinese Province” column in the address. genes in apple (MdMRS2-1 to MdMRS2-7), which were distributed across seven distinct chromosomes. Phylogenetic analysis classified these genes into five distinct clades. Tissue-specific expression profiles revealed the differential expression patterns of MdMRS2 members in different tissues such as the apple roots, stems, leaves, seedlings, seeds, flowers, and fruits. Among them, the expression level of MdMRS2-5 was the highest in fruits, while that of MdMRS2-6 was the lowest in seeds. Analysis of cis-regulatory elements in MdMRS2 promoter regions identified numerous light-responsive elements, MYB binding sites, and hormone-responsive elements, suggesting their transcriptional regulation may be influenced by related metabolic pathways or signaling molecules. qRT-PCR results showed that the relative expression levels of all genes were significantly upregulated compared with CK under M3 treatment, while there were no significant differences in other treatments. Among them, the upregulation of MdMRS2-7 was the most significant, increasing by 142% compared with CK. Notably, all MdMRS2 genes were significantly upregulated under 4 mmol·L⁻¹ MgSO₄ treatment. Subcellular localization experiments conducted in tobacco leaves confirmed the membrane and cytoplasmic distribution of these transporters, consistent with bioinformatic predictions. These genes may become candidate genes for subsequent functional studies. This work will provide a basis for future research on the response mechanism and function of the MRS2 gene family in response to magnesium stress. Full article

Yam (Dioscorea opposita) tuber development is a complex process regulated by various phytohormones, with gibberellin (GA) playing a crucial role. However, the underlying mechanisms and interaction of GA with other phytohormone pathways on yam tuber development remain incompletely understood. This study investigated the regulatory role of GA and its crosstalk with other phytohormones during yam tuber growth through phenotypic, cytological, physiological, and transcriptomic as well as targeted phytohormone metabolomics analyses. The results reveal that exogenous GA promoted tuber enlargement increases vascular bundle and the number and diameter of sieve tubes, and alters the expression of GA anabolism genes and GA signal transduction pathways. Integrated transcriptome and targeted metabolomics analyses revealed coordinated changes in GA and ethylene (ETH) biosynthesis and signaling pathways during tuber development, particularly DELLA-GAI2 acting as a negative regulator of GA signaling. Overexpression of DoDELLA-GAI2 in transgenic tobacco significantly reduced GA level, starch, cytokinin (CTK), and ETH content, as well as aerenchyma tissue growth and parenchyma cell size. Exogenous GA and ethephon treatments increased GA, starch, CTK, and ETH content, and downregulated DoDELLA-GAI2 gene expression. The yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays confirmed a direct interaction between DoDELLA-GAI2 and DoMTCPB, an upstream gene-encoding key enzyme in ETH biosynthesis. DoDELLA-GAI2 acts as a negative regulator of ETH synthesis by interacting with DoMTCPB. GA-induced degradation of DoDELLA-GAI2 relieves this inhibition, promoting ETH production and contributing to tuber growth. Taken together, our findings reveal a novel mechanism based on DoDELLA-GAI2 integrating the GA and ETH signaling processes to regulate tuber development in D. opposita, offering a potential target for improving yam crop productivity. Full article

Peripheral artery disease (PAD) is a chronic progressive accumulation of atherosclerotic lesions with varying degrees of arterial obstruction determining ischemic symptoms of the involved extremities. PAD is associated with decreased bioavailable nitric oxide due to endothelial cell dysfunction and the development and progression of vascular arterial stiffening (VAS). Atherosclerosis also plays an essential role in the development and progression of vascular arterial stiffening (VAS), which is associated with endothelial cell activation and dysfunction that results in a proinflammatory endothelium with a decreased ability to produce bioavailable nitric oxide (NO). NO is one of three gasotransmitters, along with carbon monoxide and hydrogen sulfide, that promotes vasodilation. NO plays a crucial role in the regulation of PAD, and a deficiency in its bioavailability is strongly linked to the development of atherosclerosis, VAS, and PAD. A decreased arterial patency may also occur due to a reduction in the elasticity or diameter of the vessel wall due to the progressive nature of VAS and atherosclerosis in PAD. Progressive atherosclerosis and VAS promote narrowing over time, which leads to impairment of vasorelaxation and extremity blood flow. This narrative review examines how atherosclerosis, aging and hypertension, metabolic syndrome and type 2 diabetes, tobacco smoking, and endothelial cell activation and dysfunction with decreased NO and VAS with its increased damaging pulsatile pulse pressure result in microvessel remodeling. Further, the role of ischemia and ischemia–reperfusion injury is discussed and how it contributes to ischemic skeletal muscle remodeling, ischemic neuropathy, and pain perception in PAD. Full article