Tobacco black shank (TBS) is a soil-borne disease caused by Phytophthora nicotianae (P. nicotianae), which poses a significant threat to both the yield and quality of tobacco crops. Biocontrol bacteria play a vital role in sustainable agriculture, including the management of TBS. Consequently, finding biocontrol bacteria that effectively inhibit P. nicotianae is important for tobacco production. In this study, a biocontrol bacterium with a promising control effect on TBS was isolated from the rhizosphere soil of tobacco plants, and named BY-S1. BY-S1, identified as Bacillus subtilis, exhibited an antagonistic effect of 70.60% against P. nicotianae, along with the capabilities for phosphate solubilization and siderophore production. Furthermore, an indoor potted plant experiment was conducted to explore the effect of BY-S1 on tobacco growth and resistance. The results showed that BY-S1 not only promoted tobacco growth, but also significantly reduced the TBS incidence, reaching a control efficacy of 53.45%. BY-S1 application enhanced photosynthesis, increased the activities of antioxidant enzymes (SOD, POD and CAT) and defense enzymes (PPO and PAL), and regulated the contents of plant hormones (IAA, ABA, JA and SA) to improve tobacco resistance against TBS. In addition, BY-S1 also protected tobacco from P. nicotianae infections by modulating metabolisms such as ascorbate and aldarate metabolism and tryptophan metabolism. These findings highlight the potential of BY-S1 in controlling P. nicotianae infection in tobacco.

Cadmium (Cd) is a toxic element that poses significant health risks to humans. Tobacco smoke is a primary source of human Cd exposure, aside from dietary intake. However, the mechanisms governing Cd accumulation and translocation among tobacco cultivars remain insufficiently understood. This study initially screened the Cd accumulation potential of 83 cultivars grown in China. The results revealed that KY14, K326, Yunyan99, G28, and Basma1 had higher Cd translocation ability, while 47 cultivars including Maxopka had lower Cd translocation ability. It then comparatively studied vacuolar compartmentalization, cell wall binding, glandular trichome secretion, and Cd in mainstream smoke between two contrasting cultivars under 20 μM Cd stress. K326 exhibited weaker root retention due to lower thiols contents, reduced expression of tonoplast transporter genes, and decreased uronic acid, lignin, and phenylalanine ammonia-lyase activity, facilitating Cd translocation to leaves. K326 leaves showed higher secretory detoxification ability due to the enhancement of long-stalked glandular trichome, and thus had the capacity to accommodate more Cd. Conversely, Maxopka roots immobilized Cd through enhanced vacuolar sequestration and cell wall binding, limiting its translocation. Structural equation modeling further identified CAX2, MTP1, and LTP1 to be key regulators modulating Cd accumulation in leaves. Ultimately, Cd concentrations in mainstream smoke were markedly higher in K326 than in Maxopka. These results elucidate the mechanisms underlying varietal differences in Cd translocation and offer strategies for reducing Cd accumulation in crops and its entry into the food chain.

Salinity stress severely inhibits crop growth and reduces yield. Exogenous selenium (Se) enhances plant abiotic stress tolerance, but how different selenium forms exert their impacts and pathways in mitigating salinity remains ambiguous. Under salt stress, this work compared two Se forms, selenate [Se(VI)] and selenite [Se(IV)], regarding their impacts on development, photosynthetic performance, antioxidative system, osmotic regulators, Se buildup, and stress-related gene expression in Nicotiana tabacum L. Both Se species significantly promoted tobacco growth. (1) Under 150 mmol/L NaCl stress, biomass, net photosynthetic rate and antioxidant enzyme activities decreased significantly, while soluble sugar, free proline, Na+/K+, Na+/Ca2+, H2O2, MDA contents and NtROS2a, NtLEA5 expression increased significantly. (2) Exogenous Se increased biomass, photosynthetic parameters; antioxidant enzyme activities and NtNAC2, NtCDPK12, NtROS2a expression; elevated Se deposition in roots and leaves; and reduced oxidative damage, ion imbalance and NtLEA5 expression in salt-stressed tobacco, suggesting that Se may improve salt tolerance by regulating these physiological processes and stress-related gene expression. (3) Compared with Se(IV), Se(VI) significantly increased root length, chlorophyll content, stomatal conductance, K+ content, SOD/CAT activities, leaf and root Se accumulation as well as and NtNAC2, NtCDPK12 expression, while Se(IV) resulted in higher root diameter, free proline content, Na+/K+ ratio and NtROS2a expression. In conclusion, both sodium selenate and sodium selenite effectively enhanced tobacco salt tolerance. The salt stress alleviation effect of Se(VI) may be associated with upregulating NtNAC2 and NtCDPK12 to improve antioxidant capacity and photosynthesis, thereby potentially maintaining cell membrane integrity and ion balance, while Se(IV) may exert its effect through upregulating NtROS2a to promote root thickening, reactive oxygen species scavenging and osmotic adjustment. At the tested concentrations, selenate was more effective.

Introduction:Tobacco black shank (TBS), caused by Phytophthora nicotianae, poses a serious threat to tobacco production, highlighting the urgent need for sustainable management strategies. Meanwhile, tobacco stalk, a byproduct of tobacco cultivation, required effective recycling and value-added utilization. Methods:In this study, four types of tobacco stalk derived biochar (unmodified biochar, H3PO4-modified biochar, ball-milled biochar, and ball-milled H3PO4-modified biochar) were prepared to evaluate their efficacy in controlling TBS. We evaluated physiological indices, including chlorophyll content, antioxidant enzyme activities, reactive oxygen species levels, and phytohormone profiles, along with changes in tobacco leaf metabolites, to explore the impact of modified biochar on diseased tobacco plants. Results:The ball milled-phosphorus modified biochar (BPT) exhibited a dense and uniform pore structure, markedly increased surface P content, and introduced abundant -OH and P-O functional groups, resulting in the most effective disease suppression. Soil application of BPT significantly reduced lesion length in infected plants, enhanced chlorophyll content, increased the activities of antioxidant enzymes [catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD)], decreased malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion (O2 -) levels. Moreover, BPT modulated phytohormone levels elevating indole-3-acetic acid (IAA), jasmonic acid (JA), abscisic acid (ABA), and salicylic acid (SA) and reshaped amino acid, lipid, and phenolic acid profiles. Metabolic pathway analysis indicated that BPT promoted phenylpropanoid as well as phenylalanine, tyrosine, and tryptophan biosynthesis, thereby strengthening tobacco resistance to P. nicotianae. Discussion:This study elucidate the mechanisms underlying biochar-induced disease resistance and provide a promising approach for sustainable management of tobacco black shank using modified biochar.

Chromium (Cr), a heavy metal, has significant toxic effects on plant growth and development. The exogenous application of selenium (Se) and molybdenum (Mo) has been widely demonstrated to alleviate its toxicity and enhance plant adaptability under heavy metal stress. However, the role of soil microbiota and related metabolism in the mitigation of Cr toxicity by Se and Mo is not well understood. Therefore, this study was conducted to explore the impact of combined Se and Mo application on the microecological properties of Cr-contaminated soils. The findings showed that co-application of Se and Mo enhanced tobacco plant dry weight by 85.9% and decreased Cr concentration in roots by 59.6%. The combined application of Se–Mo enhanced the expression levels of amino acids, organic acids, carbohydrates and fatty acid analogs (PUFAs). Moreover, the relative abundance of bacteria (Proteobacteria and Actinobacteriota) involved in C, N, and P cycling in Cr-contaminated soils increased. In addition, the upregulation of functional genes associated with the C cycle (mnp, abfA, sga, rbcL and pmoC), N fixation (nifH), nitrification (amoA), and P cycle (phoD), as well as the downregulation of denitrification (nirK1 and nirS2), promoted C, N, and P cycling in soil and ultimately mitigated Cr toxicity. The application of Se and Mo promoted the activation of carbon, nitrogen, and phosphorus nutrients by increasing soil pH, organic matter (SOM) content, and urease and sucrose activities, as well as a marked boost in alkaline phosphatase activity (SALP). Stimulating microbial activity and optimizing nutrient cycling, the combined application of Se and Mo alleviates Cr stress by modulating soil properties and directly regulating microbial functional genes. Our findings offer novel insights into the mechanisms through which Se and Mo alleviate Cr toxicity in contaminated soils.

WRKY, a plant-specific transcription factor protein family, participates in various stress responses. However, reports on the association of WRKY transcription factors with tobacco diseases are lacking. Therefore, we investigated whether the tobacco transcription factor NtWRKY70 confers disease resistance by using tobacco black stem disease, caused by Phytophthora nicotianae, to study the role of NtWRKY70 in disease resistance. The expression of NtWRKY70 in tobacco overexpression lines was significantly higher than that in wild-type (WT) plants during the infection process. The the area of infected NtWRKY70 overexpression lines stained with trypan blue was lower than that of the WT and knockout mutant lines, and the degree of damage was the lower. The net photosynthetic rate, stomatal conductance and transpiration rate of the overexpressing plants were significantly higher than those of WT and knockout mutant plants. NtWRKY70 overexpression lines showed higher superoxide dismutase, peroxidase and catalase and significantly higher phenylalanine ammonia-lyase and polyphenol oxidase activities related to disease resistance. Additionally, , H2O2 and malondialdehyde contents and relative conductivity decreased. Reverse transcription-quantitative PCR indicated significantly upregulated expression of NtSOD, NtPOD and NtCAT in NtWRKY70 overexpression lines, enhancing the antioxidant resistance of tobacco, as well as upregulated expression of NtPAL, NtPPO and NtPR1 defence genes, further improving the disease resistance of plants. Therefore, NtWRKY70 plays an active regulatory role in resistance to P. nicotianae infection. This study provides candidate genes for future tobacco disease-resistance breeding.

Cadmium (Cd) is a heavy metal pollutant that impedes plant growth. Sulfur (S), a nutrient, possesses the ability to detoxify Cd. Nevertheless, the dose effect of S on Cd detoxification and the mechanism by which S modulates Cd accumulation and detoxification, remain insufficiently understood. Here, two Nicotiana species with distinct Cd accumulation strategies were hydroponically cultivated under varying S:Cd molar ratios (250:1, 500:1, 750:1, 1000:1). This study aimed to assess the effects of different S doses on Cd accumulation and detoxification and to clarify the underlying mechanisms from multiple perspectives. Results identified 500:1 as the optimal S:Cd ratio, beyond which detoxification diminished, reflecting a hormetic response. Integrated physiological, biochemical, transcriptomic, and metabolomic analyses revealed species-specific pathways of S-mediated detoxification between two Nicotiana species. Specifically, the S-mediated Cd translocation factor from roots to leaves in N. tabacum increased from 1.22 to 2.70, whereas it decreased from 0.25 to 0.20 in N. rustica. N. tabacum prioritizes shoot-based Cd detoxification via glutathione mobilization (62.96 % increase), transporter activation (NRAMP/HMA/ZIP), and enhanced trichome secretion (1.12-fold glandular trichome density). Conversely, in N. rustica, S redirected metabolism towards phytochelatins-dominated thiols (1.22-fold), enhancing Cd chelation detoxification, along with lignin fortification (3 % increase in cell wall Cd) and vacuolar sequestration (ABC/CAX) in roots. These findings demonstrate that S mediates divergent detoxification strategies across species, offering potentially valuable information for developing targeted strategies to enhance crop Cd remediation, either via shoot-driven phytoextraction or root-based immobilization for food safety.

To provide a scientific foundation for the efficient use of biochar microbial fertilizer to improve both quality and production, this study will look at the impact of applying biochar microbial fertilizer at different fertility levels on the soil environment and flue-cured tobacco quality. We investigated the impact of biochar microbial fertilizer on tobacco agronomic indicators, flue-cured tobacco yield and quality, rhizosphere soil physical and chemical properties, and diversity of microbial communities. (1) Fertilization treatment significantly increased tobacco stem circumference, leaf number, and size during the tobacco maturation period, optimized economic traits, and improved the physical properties of tobacco leaves. In addition, fertilization can increase total alkaloid, potassium, and aromatic substance levels in flue-cured tobacco and improve its overall quality. (2) After applying biochar microbial fertilizer, the amount of readily available nutrients in the soil around tobacco roots went way up, and the soil structure got better. (3) Biochar microbial fertilizer changed the rhizosphere soil microbial composition and diversity. (4) Pearson's correlation analysis showed that there was a significant correlation between key rhizosphere soil microorganisms and the chemical constituents of flue-cured tobacco, which showed characteristic positive/negative correlations. Biochar microbial fertilizer improves tobacco agronomic indicators, cured tobacco leaf quality, and yield. Biochar microbial fertilizer changed the rhizosphere soil's microbial composition and diversity. The diversity and composition of rhizosphere soil microorganisms may also affect the soil's chemical composition.

Abstract Objective To investigate the clinical efficacy of cytoreductive surgery in oligometastatic hormone-sensitive prostate cancer (omHSPC). Methods The basic characteristics, treatment strategies and long-term follow-up of 181 patients with omHSPC were retrospectively analyzed. All patients were divided into cytoreductive surgery group and no local therapy group according to the administration of cytoreductive surgery before progression to metastatic castration-resistant prostate cancer (mCRPC). Subsequently, our study explored the effect of cytoreductive surgery on CRPC-free survival in omHSPC patients. Results A total of 181 patients were enrolled in the study, including 48 patients who received cytoreductive surgery and 133 patients who did not receive local therapy. No significant differences were detected between the two groups regarding prostate-specific antigen (PSA) at the initial diagnosis (P = 0.194), the International Society of Urological Pathology (ISUP) grade group (P = 0.158), the treatment options during omHSPC (P = 0.090), common comorbidities (P = 0.649) and the number of metastases (P = 0.291). The proportions of patients with Tx stage (P = 0.027) and Nx stage (P = 0.027) in the no local therapy group were significantly higher than that in the cytoreductive group. After propensity score matching (PSM), it was found that cytoreductive surgery could significantly improve the CRPC-free survival of omHSPC patients (hazard ratio (HR) = 0.537, 95% confidence interval (CI) = 0.317–0.909, P = 0.016). Conclusion Cytoreductive surgery can significantly improve the CRPC-free survival of omHSPC patients. Additionally, large sample-size, prospective and randomized controlled studies are needed to validate the results of our study in the future.

Copper (Cu) contamination impairs crop performance. Selenium (Se), a beneficial element for plants, has been implicated in mitigating heavy-metal stress. However, the role of Se against Cu toxicity in tobacco (Nicotiana tabacum L.) remains incompletely characterized. Using Cu-stressed tobacco seedlings with Se supplementation, we show that excess Cu disrupted chloroplast structure, perturbed photorespiration, and interfered with chlorophyll biosynthesis and disrupted the Calvin-Benson cycle (including Ribulose-1,5-bisphosphate (RuBP) regeneration), thereby reducing photosynthetic efficiency. Se preserved chloroplast integrity and enhanced pigment synthesis, improving leaf photosynthetic performance. Se application also significantly decreased soil available Cu, which lowered plant Cu uptake and translocation, while concurrently promoting mineral nutrient acquisition. Moreover, Se modulated antioxidant defenses to mitigate oxidative damage and maintain cellular structure and function. At the metabolic level, Se appeared to confer Cu tolerance through regulation of glutathione metabolism and amino-acid pathways (notably histidine, arginine, and proline), accompanied by changes in glutamate, glutathione, and phosphoserine. Collectively, this study suggested that Se might alleviate Cu phytotoxicity through multiple, concerted pathways -including lowering soil-available Cu, reducing plant Cu uptake, safeguarding chloroplast/photosynthetic processes, and modulating antioxidant and amino-acid metabolism.

Continuous tobacco cultivation over an extended period of time has decreased tobacco production quality, disturbed soil microbial populations and disrupted the soil structure. Therefore, measures to mitigate these ongoing cropping problems must be implemented. To improve the soil quality caused by continuous cultivation of tobacco, so as to promote the growth of tobacco and improve the yield and quality of tobacco, which is of great significance to promote the sustainable development of agriculture. We investigated the effects of green fertilizers and soil conditioners on the physicochemical characteristics, microbial diversity and chemical composition of flue-cured tobacco in continuous cropping soil. (1) When green fertilizers and soil amendments were applied, the bulk density of continuous cropping soil decreased, its porosity increased, and its fraction of macroaggregates in it increased. (2) The amount of available nitrogen (AN) and available phosphorus (AP) in the soil used for continuous cropping increased with the application of green fertilizers and soil additives. (3) The application of green fertilizers and soil additives altered the rhizosphere soil microbial composition and enhanced the diversity of the microbial community. (4) The alteration of rhizosphere soil physical and chemical properties indirectly affected the chemical composition and coordination of flue-cured tobacco. The chemical composition and coordination of flue-cured tobacco might be affected by the physicochemical characteristics of the soil used for continuous cropping tobacco and the composition and community diversity of rhizosphere soil microorganisms. Furthermore, the most notable improvement in the soil for continuous cropping was attained by applying a combination of soil conditioner and green fertilizer.

In this study, we treated tobacco seedlings with 0, 200, 400, and 800 mg/kg Pb2 +, and explored the response mechanism of tobacco under Pb stress through a combination of growth physiology and metabolomics analysis. The physiological results showed that compared with CK, with the increase of Pb concentration, Pb treatment inhibited tobacco growth, reduced the biomass and photosynthetic pigment content of tobacco seedlings, and severely damaged the chloroplast structure. In addition, compared with CK, the pore conductivity and pore density of Pb800 treatment decreased by 45.77 % and 93.55 %, respectively. Pb treatment disrupted the cell membrane system, and Pb800 treatment increased the content of malondialdehyde (MDA) in leaves and roots by 67.65 % and 31.90 %, respectively. Meanwhile, Pb treatment increased the activity of tobacco SOD and POD enzymes. Metabolomics results showed that Pb stress enhanced tryptophan metabolism, glutathione metabolism, alanine, aspartate, and glutamate metabolism, as well as cysteine and methionine metabolism pathways. These results indicate that increasing the content of photosynthetic pigments and hormones, clearing reactive oxygen species by enhancing antioxidant enzyme activity, and improving amino acid metabolism may play an important role in reducing the toxicity of Pb to tobacco.

Molybdenum (Mo) is widely used as a micronutrient fertilizer to improve plant growth and soil quality. However, the interactions between cell wall biosynthesis and molybdenum have not been explored sufficiently. This study thoroughly investigated the regulatory effects of different concentrations of Mo on tobacco cell wall biosynthesis from physiological and metabolomic aspects. The results indicate that Mo treatment increased the Mo content of tobacco variety K326. Moreover, it significantly up-regulated the gene expression levels of molybdases (NR, AO, SO, XDH) and molybdate transporters in tobacco, whereby the gene expression levels of NR were upregulated by 28.48%, 52.51%, 173.05%, and 246.21%, respectively; and MOT1 and MOT2 were upregulated by 21.49/8.67%, 66.05/30.44%, 93.05/93.26%, and 166.11/114.29%, respectively. Additionally, Mo treatment regulated the synthesis of related enzymes, effectively promoted plant growth, and significantly increased biomass and dry matter accumulation, with the biomass in the leaves increasing significantly by 30.73%, 40.72%, 46.34%, and 12.88%, respectively. The FT-NIR spectroscopy results indicate that after Mo was applied to the soil, the quantity of C-O-C, -COOH, C-H, and N-H functional groups increased. Concurrently, the contents of cellulose, hemicellulose, lignin, protopectin, and soluble pectin in the leaves significantly increased, wherein the content of soluble pectin and hemicellulose increased significantly by 31.01/288.82%, 40.69/343.43%, 69.93/241.73%, and 196.88/223.26%, respectively. Furthermore, the cell walls thickened, increasing the ability of the plant to withstand disturbances. The metabolic network diagrams indicate that Mo regulated galactose metabolism, and arginine and proline acid biosynthesis. The contents of carbohydrates, spermidine, proline, quinic acid, IAA, flavonoids, and other substances were increased, increasing the levels of polysaccharides and pectin within the cell wall, controlling lignin production, and successfully enhancing resistance to abiotic stress. These results offer important perspectives for further investigations into the role of trace elements.

Tobacco black shank (TBS) is a soil-borne fungal disease caused by Phytophthora nicotiana (P. nicotianae), significantly impeding the production of high-quality tobacco. Molybdenum (Mo), a crucial trace element for both plants and animals, plays a vital role in promoting plant growth, enhancing photosynthesis, bolstering antioxidant capacity, and maintaining ultrastructural integrity. However, the positive effect of Mo on plant biotic stress is little understood. This study delves into the inhibitory effects of Mo on P. nicotianae and seeks to unravel the underlying mechanisms. The results showed that 16.32 mg/L of Mo significantly inhibited mycelial growth, altered mycelial morphological structure, damaged mycelial cell membrane, and ultimately led to the leakage of cell inclusions. In addition, 0.6 mg/kg Mo applied in soil significantly reduced the severity of TBS. Mo increased photosynthetic parameters and photosynthetic pigment contents of tobacco leaves, upregulated expression of NtPAL and NtPPO resistance genes, as well as improved activities of SOD, POD, CAT, PPO, and PAL in tobacco plants. Furthermore, Mo could regulate nitrogen metabolism and amino acids metabolism to protect tobacco plants against P. nicotianae infection. These findings not only present an ecologically sound approach to control TBS but also contribute valuable insights to the broader exploration of the role of microelements in plant disease management.

Chromium (Cr) is a hazardous heavy metal that negatively affects animals and plants. The micronutrients selenium (Se) and molybdenum (Mo) have been widely shown to alleviate heavy metal toxicity in plants. However, the molecular mechanism of Cr chelation on the cell wall by combined treatment with Se and Mo has not been reported. Therefore, this study aimed to explore the effects of Se-Mo interactions on the subcellular distribution of Cr (50 µM) and on cell wall composition, structure, functional groups and Cr content, in addition to performing a comprehensive analysis of the transcriptome. Our results showed that the cell walls of shoots and roots accumulated 51.0% and 65.0% of the Cr, respectively. Furthermore, pectin in the cell wall bound 69.5%/90.2% of the Cr in the shoots/roots. Se-Mo interactions upregulated the expression levels of related genes encoding galacturonosyltransferase (GAUT), UTP-glucose-1-phosphate uridylyltransferase (UGP), and UDP-glucose-4-epimerase (GALE), involved in polysaccharide biosynthesis, thereby increasing pectin and cellulose levels. Moreover, combined treatment with Se and Mo increased the lignin content and cell wall thickness by upregulating the expression levels of genes encoding cinnamyl alcohol dehydrogenase (CAD), peroxidase (POX) and phenylalanine amino-lyase (PAL), involved in lignin biosynthesis. Fourier-transform infrared (FTIR) spectroscopy results showed that Se + Mo treatment (in combination) increased the number of carboxylic acid groups (-COOH) groups, thereby enhancing the Cr chelation ability. The results not only elucidate the molecular mechanism of action of Se-Mo interactions in mitigating Cr toxicity but also provide new insights for phytoremediation and food safety.

Tobacco black shank (TBS), caused by Phytophthora nicotianae, poses a significant threat to tobacco plants. Selenium (Se), recognized as a beneficial trace element for plant growth, exhibited inhibitory effects on P. nicotianae proliferation, disrupting the cell membrane integrity. This action reduced the energy supply and hindered hyphal transport through membrane proteins, ultimately inducing hyphal apoptosis. Application of 8 mg/L Se through leaf spraying resulted in a notable decrease in TBS incidence. Moreover, Se treatment preserved chloroplast structure, elevated chitinase activities, β-1,3-GA, polyphenol oxidase, phenylalanine ammonia-lyase, and increased hormonal content. Furthermore, Se enhanced flavonoid and sugar alcohol metabolite levels while diminishing amino acid and organic acid content. This shift promoted amino acid degradation and flavonoid synthesis. These findings underscore the potential efficacy of Se in safeguarding tobacco and potentially other plants against P. nicotianae.

This study isolated a myosmine-degrading bacterial strain J-6 from tobacco-growing soil. The identification of this strain revealed it to be a new species within the genus Sphingopyxis. Analysis of the myosmine degradation products by HPLC, preparative HPLC, and UHPLC-MS/MS identified 8 metabolites, among which 3-pyridylacetic acid (3-PAA), 5-(3-pyridyl)tetrahydrofuranone-2 (PTHF), and 4-hydroxy-4-(3-pyridyl)butanoic acid (HPBA) were three novel metabolites that were not previously found in microbial degradation of tobacco alkaloids. Interestingly, these metabolites have been observed in the nicotine metabolic pathways of humans and animals. In addition, 3-PAA, which is believed to be the major end product of nicotine metabolism in humans, is also found to be an end product of myosmine degradation in strain J-6. Based on the identified metabolites and genomic analysis, a previously unreported bacterial degradation pathway for tobacco alkaloids was proposed. The downstream part of this pathway for converting SP to 3-PAA resembles the pathway for mammalian metabolism of SP to 3-PAA. Overall, the findings in this study offer novel insights into the degradation pathways and mechanisms of myosmine, which will deepen our understanding on the fate of myosmine both in the environment and within the human body.

Hydrogen sulfide (H2S) has emerged as a potential regulator of plant responses to abiotic stress. In this study, we investigated the effects of exogenous sodium hydrosulfide (NaHS) on tobacco seedlings subjected to polyethylene glycol (PEG)-induced drought stress. Compared to control conditions, drought stress significantly reduced several parameters in tobacco seedlings, including shoot dry weight (22.83%), net photosynthesis (37.55%), stomatal conductance (33.56%), maximum quantum yield of PSII (Fv/Fm) (11.31%), photochemical quantum yield of PSII (ΦPSⅡ) (25.51%), and photochemical quenching (qP) (18.17%). However, applying NaHS, an H2S donor, mitigated these effects, ultimately enhancing photosynthetic performance in tobacco seedlings. Furthermore, optimal NaHS concentration (0.4 mmol/L) effectively increased leaf relative water content (RWC) and root activity while promoting the accumulation of soluble sugars and proline content to maintain osmotic pressure balance under drought stress. NaHS pretreatment also bolstered the antioxidant defense system in leaves, leading to a reduction in hydrogen peroxide (H2O2) and malondialdehyde (MDA) content and an increase in the activities of antioxidant enzymes such as ascorbate peroxidase (APX), superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). Consequently, NaHS protected chloroplast structure and attenuated chlorophyll degradation, thus mitigating severe oxidative damage. Overall, our findings provide valuable insights into exogenous NaHS's role in enhancing tobacco drought tolerance. These results lay the foundation for further research utilizing H2S-based treatments to improve crop resilience to water deficit conditions.

Cancer-associated fibroblasts (CAFs) play a pivotal role in the metabolic symbiosis that drives tumor proliferation and immune evasion. Paradoxically, eliminating CAFs can disrupt tissue homeostasis and potentially accelerate tumor spread. To address this challenge, this study proposes a novel strategy to reprogram CAFs, transforming them into "anchors" and "fuel stations" for anti-tumor immune cells, thereby enhancing the immune response against tumors. Utilizing a fibroblast-specific lipid nanoparticle (LNP) delivery system, key metabolic genes in CAFs are targeted and downregulated, specifically hexokinase 2 (HK2) and mitochondrial cytochrome c oxidase I (MTCO1). The dual inhibition of glycolysis and mitochondrial respiration in CAFs consequently results in glucose overload and mitochondrial dysfunction. As a result, these energy-deprived CAFs exhibit high expression of MHC II molecules and inflammatory cytokines, promoting immune cell infiltration and providing essential fuel for subsequent activation and proliferation. Furthermore, this metabolic reprogramming results in reduced angiogenesis and an immune microenvironment characterized by M1 macrophage polarization and enhanced lymphocyte infiltration. Consequently, this approach improves the efficacy of immune checkpoint inhibitors (ICIs) in castration-resistant prostate cancer (CRPC). Thus, the reprogramming of CAFs into immune cell allies offers a promising strategy to overcome the limitations of current ICIs therapies.