Purpose Gamma-ray mutagenesis is a widely used technique in plant breeding, but its efficiency depends on the developmental stage, genotype, and timing of irradiation after pretreatment. The aim of this study was to determine the radiosensitivity of two Korean tobacco cultivars, Hyangcho and KB113LC, across developmental stages and to explore whether methyl jasmonate (MeJA) treatment can modulate the expression of target gene sets to enhance mutation induction. Materials and methods Tobacco seeds (ranging from 0 to 1000 with 100 Gy steps) and plants at the vegetative and reproductive stages (ranging from 0 to 200 with 25 Gy steps) were irradiated with γ-rays, and growth parameter data were collected to determine 50% reduction dose (RD50) values. The non-irradiated control plants at vegetative and reproductive stages were treated with 500 µM MeJA by foliar spraying, and temporal expression of MeJA-responsive and nicotine biosynthesis-related genes was assessed using qRT-PCR over a 0–48 h period. Results The RD50 mean values of each parameter varied by cultivar and stage, with Hyangcho (mean 66 Gy) showing greater radiosensitivity than KB113LC (mean 79 Gy) at both the vegetative and reproductive stages but greater resistance at the seed stage (mean 405 vs. 312 Gy, Hyangcho vs. KB113LC). MeJA treatment induced no obvious physiological alterations; however, the expression of early-response genes (e.g., NtJAZ1, NtMYC2a) peaked at 0.5–1 h post-MeJA treatment, while late-response genes (e.g., NtERF189, NtQPT2) peaked at 16–32 h, with NtODC showing particularly strong activation in KB113LC. Conclusions The study findings support the introduction of a practical framework for stage- and genotype-specific γ-ray mutagenesis in tobacco, guided by the timing of MeJA-responsive gene activations. Based on the literature, MeJA pretreatment is assumed to potentially increase mutagenesis efficiency; our data define optimal conditions for testing this hypothesis, supporting the development of tobacco mutant populations, including low-nicotine tobacco lines aligned with evolving public health guidelines.

The nonoxidative deamination of β-branched aromatic compounds, such as phenylalanine, is a key step in the synthesis of natural products and pharmaceutically active ingredients. However, it remains challenging due to the complexity of the substrates. Phenylalanine ammonia-lyase (PAL) is a promising green catalyst, but its application is hindered by the limited availability of suitable types, low catalytic activity, and poorly understood mechanistic properties. Here, we report a novel PAL in Nicotiana tabacum (NtPAL). Through comprehensive computational analysis, we elucidated the mechanisms underlying the enhanced thermostability and dual-substrate affinity of NtPAL, which represents the first PAL with substrate promiscuity identified in dicotyledonous plants. By generating multisite substitution mutants, we identified two parallel mechanisms for thermostability, entropy-driven and enthalpy-driven, and clarified the roles of key amino acids and substrate trajectories in catalytic process. This study provides new insights into the functional mechanisms of NtPAL and presents an efficient biocatalyst for asymmetric synthesis.

First report of Fusarium falciforme causing wilt in tobacco (Nicotiana tabacum L.) in India

Integrating multi-omics reveals the mechanisms of elevated [CO2] enhances salt tolerance of tobacco plants with a photosynthetic regulatory network.

Chloroplast starch granules reflect solar radiation and protect plants from photo-oxidative stress under hypothermia.

Anther culture is an effective biotechnological approach to accelerate the production of homozygous lines in tobacco breeding. This study evaluated the interaction between culture media (Murashige and Skoog/MS and Chu’s N6) and silver nanoparticle (AgNP) concentrations on in vitro anther regeneration of tobacco (Nicotiana tabacum L.). The experiment was arranged in a completely randomized design with ten treatment combinations consisting of two basal media and five AgNP concentrations (0, 2.5, 5, 7.5, and 10 ppm), each replicated three times. Quantitative parameters included callus formation, shoot regeneration, rooting response, regeneration percentage, and contamination rate. MS medium supplemented with 2.5 ppm AgNPs (K2) produced the optimal response, showing 100% callus formation and the highest shoot regeneration percentage (89%). Root formation was observed only in treatments K2 and K4. In contrast, higher AgNP concentrations (≥7.5 ppm), particularly in Chu’s N6 medium, significantly reduced regeneration percentages (ANOVA, p<0.05). The promotive effect of low AgNP concentration is associated with suppression of ethylene activity, antimicrobial action, and regulation of reactive oxygen species (ROS), which collectively enhance cell division and organogenesis. These findings indicate that MS medium supplemented with 2.5 ppm AgNPs is optimal for tobacco anther regeneration and suitable for doubled-haploid production.

Tobacco (Nicotiana tabacum L.) is a globally important economic crop and a rich source of bioactive cembratriene-4,6-diol (CBT-diol). The unique macrocyclic scaffold of these compounds has prompted an extensive study of its bioactivity. Although CBT-diol has known antitumor activity, its specific molecular targets remain unclear, hindering the translational development of tobacco-based therapeutics. In this study, we identified ALDOA as the direct target of tobacco-derived α-CBT-diol against A549 lung cancer cells. Using activity-based proteomics and target validation methods, we show that α-CBT-diol binds to the ALDOA catalytic site with high affinity (Kd = 12.4 μM) and inhibits its activity. Definitively, studies in ALDOA-knockout cells confirmed that α-CBT-diol inhibits ALDOA activity, thereby suppressing tumor glycolysis and growth by reducing glucose uptake and lactate production. To the best of our knowledge, α-CBT-diol represents the first identified member of the tobacco cembranoid class that exerts antitumor effects by targeting ALDOA.

Characterization of the Nt4CL gene family in Tobacco (Nicotiana tabacum) and reveals Nt4CL9 response to cold stress

Whole-genome sequencing of 2032 diverse tobacco accessions reveals genetic variation and population differentiation.

Specific generation of reactive oxygen species (ROS) is important for signalling and defence in many organisms. In plants, different types of ROS serve useful biological functions in the extracellular space (apoplast), influencing polymer structures as well as signalling during immune responses. The current knowledge of apoplastic ROS dynamics is limited, as dynamic monitoring of extracellular redox processes in vivo remains difficult. We employed evolutionary distant land plant model species from bryophytes and flowering plants to test whether the genetically encoded redox biosensor roGFP2-Orp1 can be used to assess extracellular redox dynamics. Secreted roGFP2-Orp1 can provide information about local diffusion barriers and protein cysteinyl oxidation rate in the apoplast, after pre-reduction. Observed re-oxidation rates were slow - within the range of hours. Compared to Physcomitrium patens, re-oxidation in Arabidopsis thaliana was faster and increased after triggering an immune response. Comparing roGFP2-Orp1 signals in tip-growing P. patens protonema and Nicotiana tabacum pollen tubes, we consistently find no intracellular redox gradient, but a partially reduced extracellular sensor in pollen tubes. Our data indicate differences in extracellular oxidative processes between species and within a species, depending on cell type and immune signalling.

The movement, distribution, and interactions of organelles are cell-type specific, responding to fluctuating metabolic and environmental cues and governing the efficiency of plant physiology and stress response. The directional motility of various plant organelles is predominantly driven by the actomyosin system, yet the distinct functionality of these organelles across plant tissues presupposes organelle-specific regulation of motility, which requires the detection of subtle shifts in dynamics. Meanwhile, studies that comprehensively characterize and directly compare the simultaneous movement of multiple types of organelles within the same cell are limited. Here, we visualized peroxisomes, mitochondria, chloroplasts, Golgi bodies and actin filaments simultaneously in tobacco (Nicotiana tabacum) to evaluate organelle organization and motility within the context of one another. Quantitative analysis of multiple motility factors enabled us to identify peroxisome motility in tobacco mesophyll as distinct from other organelles. Further analysis in Arabidopsis (Arabidopsis thaliana) revealed that both mitochondria and peroxisomes are slower in mesophyll cells compared to epidermis in normal growth conditions, but their motility patterns are unique from one another across leaf tissue after plants experienced conditions that induce photorespiration, a metabolic pathway requiring the concerted action of chloroplasts, peroxisomes and mitochondria. Our quantitative analysis of thousands of organelles across species, cell type, and physiological conditions unveils distinct modulation of motility according to organelle identity and function. The extensive combinatorial characterizations of plant organelle movement provide a fundamental resource for the future discovery of molecular mechanisms driving the movement and distribution of diverse organelles.

Boosting lactoferrin yields in Nicotiana tabacum via HC-Pro co-agroinfiltration.

This study aims to determine the effect of various concentrations of dry tobacco stem bark extract (Nicotiana tabacum var. Virginia) on armyworm pests (Spodoptera litura F.) and the presence of predators on potato plants (Solanum tuberosum L.). The experiment was conducted in Sembalun Village, East Lombok Regency, from July to September 2024. The parameters observed were pest population, intensity of pest attacks, presence of pest enemies, number of tubers, and tuber weight. This study used a Randomised Block Design consisting of 6 treatments (T) with four replications, namely T0 (control), T1 (abamectin), T2 (tobacco extract 30 ml/1000 ml water), T3 (tobacco extract 40 ml/1000 ml water), T4 (tobacco extract 50 ml/1000 ml water) and T5 (tobacco extract 60 ml/1000 ml water). The results showed that the use of botanical pesticides from dry tobacco stem bark can reduce the population and intensity of armyworm attacks. Application with a concentration of 30 ml/L water (T2) had a different effect compared to the control treatment (T0). The higher the concentration used, the higher the ability to suppress pest populations and the intensity of pest attacks. The percentage of dry tobacco bark yield at a concentration of 60 ml/L water (T5) did not differ significantly from the chemical pesticide abamectin (T1) in suppressing the population and intensity of attacks by armyworms (Spodoptera litura F.).

Antarctic Mokoshia mucilaginosa and Mokoshia rubra are associated with improved salinity tolerance in Nicotiana tabacum through coordinated regulation of photosynthetic performance and antioxidant responses, highlighting the potential of polar bacteria as bioinoculants for sustainable agriculture in saline and cold-affected ecosystems. Soil salinity is an escalating global challenge that constrains crop productivity worldwide, with particularly severe impacts in marginal agroecosystems, including those in cold regions. Here, we provide evidence that two psychrotolerant Antarctic bacterial strains, Mokoshia mucilaginosa and Mokoshia rubra, function as plant growth-promoting bioinoculants that alleviate NaCl-induced stress in Nicotiana tabacum. Both strains exhibited key plant growth-promoting traits, including indole-3-acetic acid production, phosphate solubilization, siderophore production, and nitrogen fixation. Under salinity levels of 50-150mM NaCl, bacterial inoculation was associated with improved plant performance, including enhanced biomass accumulation, improved photosystem II efficiency (Fv/Fm, ΦPSII, PIABS), and increased pigment contents (chlorophylls and carotenoids), alongside modulation of antioxidant enzyme activities (SOD, POD, CAT, and APX). Fluorescence kinetics and spectral reflectance indices further revealed distinct multivariate patterns separating inoculated plants from uninoculated salt-stressed controls. Together, these results suggest that Antarctic Mokoshia spp. contribute to improved photosynthetic function and redox regulation under salinity stress. To our knowledge, this study provides the first report linking members of the genus Mokoshia with enhanced salt stress tolerance in plants, highlighting their potential as sustainable microbial tools for improving crop performance in saline agroecosystems.

The efficacy of cry genes in different plant species is critical for the design and implementation of stewardship plans targeting resistance to polyphagous insects in multiple crops. Transgenic plants of three solanaceous species: Nicotiana tabacum L. (tobacco), Solanum aethiopicum L. (scarlet eggplant), and Solanum tuberosum L. (potato) were therefore transformed using the same binary vector with a cry 1Ac9 gene and assessed in bioassays against the same population of potato tuber moth (PTM; Phthorimaea operculella ). The insect resistance conferred by the cry 1Ac9 gene differed markedly among the three plant species. The cry 1Ac9 gene was most effective in scarlet eggplant, with all four transgenic lines exhibiting high mortality of neonate PTM larvae (60%–100% mortality) and very low mean larval growth index. All 24 transgenic lines of tobacco produced significantly reduced mean larval growth indices, with 50% of the lines exhibiting 7%–33% mortality. Among the 119 transgenic potato lines from six cultivars the mean larval growth indices were substantially higher, with only 85% exhibiting significant growth inhibition. No larval mortality was observed on the transgenic potato lines. The findings have important implications for managing polyphagous insect pests when the same cry gene is deployed in multiple crops.

F-box-LRR (FBXL) proteins are crucial components of the SCF ubiquitin ligase complex, regulating diverse processes such as development and stress responses in plants. However, the FBXL family in tobacco (Nicotiana tabacum L.) remains poorly characterized. This study performed the first genome-wide analysis of the FBXL gene family in tobacco and identified 47 NtaFBXL genes. Phylogenetic analysis classified them into five clades, among which Clade III exhibited notable expansion. Promoter analysis revealed abundant stress- and hormone-related cis-elements. Expression profiling demonstrated tissue-specific patterns and strong responses to drought, ABA, IAA, and TMV infection. Importantly, six genes exhibited a significant negative correlation with TMV accumulation, suggesting their potential roles in antiviral defense. Moreover, both drought and TMV stress triggered a disturbance of redox homeostasis, a dynamic process that was closely associated with the expression of specific NtaFBXL genes, characterized by upregulated antioxidant enzymes (SOD, POD, CAT) and accumulated oxidative markers (H2O2, MDA). Collectively, this study provided a foundational resource for understanding the function of NtaFBXLs and identified key candidate genes for the genetic improvement of stress resistance in tobacco.

This study examines the utilization of Nicotiana tabacum and Capsicum annuum as bioresources for the development of sustainable, organic pesticides aimed at controlling maize caterpillars. Conducted across Gatsata, Nyamata, and Byimana, the research evaluates the efficacy of plant extracts in reducing fall armyworm populations. Nicotiana tabacum leaves and Capsicum annuum fruit extract were prepared, steeped in water, strained, and refrigerated. Extracts were diluted into low, medium, and high concentrations to test the pesticidal effects on maize caterpillars. These extracts were applied to maize caterpillars in controlled and uncontrolled environments to monitor mortality rates. Caterpillar abundance was recorded across three sites using 10m x 10m plots. The study found Nicotiana tabacum and Capsicum annuum extracts have significant pesticidal activity, and the mortality of maize caterpillars ranges from 81 to 84%. These findings highlight the potential of these botanical extracts as eco-friendly alternatives to synthetic pesticides, promoting sustainable agriculture by reducing environmental impact and preserving beneficial insects. The research recommends optimizing the application methods and dosage of these extracts for effective pest management and further exploring their long-term effects on biodiversity.

Curly top disease (CTD) affects sugar beet, tomato and other crops, resulting in stunted plants with severely curled leaves and reduced yields. The disease occurs worldwide and is caused by geographically associated monopartite geminiviruses transmitted mostly by leafhoppers. However, the aetiology of CTD in South America remains unknown because the disease disappeared in the 1950s. Here, we describe how the chance finding of tomato plants with CTD-like symptoms in Brazil in 2016 and high-throughput sequencing helped identify a novel ~2.6 kb geminivirus DNA associated with curly top disease in Mato Grosso (GV-CTD-MT) that induced CTD symptoms in agroinoculated tomato and Nicotiana benthamiana Domin. plants and produced geminivirus-like virions in infected plants. Evidence GV-CTD-MT may be the genomic DNA of the historic Brazilian curly top virus (BraCTV) includes (i) occurring in the same geographic location (Brazil); (ii) inducing nearly identical CTD symptoms in tobacco (Nicotiana tabacum L.) and tomato plants to those described in the 1940s for the BraCTV; (iii) inducing CTD in a similar broad host range of plant species as previously reported for BraCTV based on leafhopper transmission experiments; (iv) the co-phylogenetic analysis predicting the vector of GV-CTD-MT is Agallia sp. leafhoppers; and, importantly, (v) transmission experiments showing Agallia albidula, the known vector of BraCTV, is a competent vector of GV-CTD-MT. Sequence and phylogenetic analyses revealed that this novel CTD-inducing geminivirus has a chimeric genome, a long evolutionary history, and is closely related to monopartite geminiviruses recently identified in South America. These viruses were placed in the new genus Topilevirus, the fifth genus whose members induce CTD. Thus, our results suggest that BraCTD, which disappeared over 70 years ago, and possibly historic CTDs of sugar beet in South America were caused by topileviruses transmitted by indigenous leafhoppers, thereby solving the conundrum left by first-generation researchers.

In September 2022, a severe outbreak of stem rot disease occurred on Nicotiana tabacum cultivar Yunxue 1 in Lujiang Town, Baoshan City, Yunnan Province of China (98°45′-98°57′ E, 24°48′-25°17′ N). Symptoms included water-soaked lesions on stems and leaves that turned brown and rotted inward. Infected plants gradually wilted, defoliated, emitted a foul odor, and eventually died (Figure 1). Statistically, in a field of 0.8 ha,the disease incidence was 30% and the affected cultivar with Yunxue 1. Ten typical samples of cigar tobacco blackleg were collected from the Baoshan tobacco plantation, rinsed with sterile water, soaked in 75% ethanol for 30 seconds, and then rinsed with sterile water three times. The samples were then plated onto nutrient agar (NA) and incubated at 28°C. A total of 10 pathogenic strains were isolated. After 24 hours of incubation at 28°C ± 1°C in nutrient agar (NA) medium, the purification culture was carried out, and the most pathogenic strain, numbered BS113, was obtained.Pathogenicity tests were conducted using the capillary tube method. The purified bacterial strain was inoculated into NA liquid medium and cultured at 28°C for 18-24 h. The bacterial concenration was adjusted to 108 CFU/mL with sterile water, and 20 μL was injected into the stem base of 60-day-old tobacco plants (Yunxue 1), with sterile water as the control. The plants were grown under conditions of 28°C and 80% humidity, and disease symptoms were observed, with the color, size, location, and severity of lesions recorded at different stages of disease development. Symptoms appeared on the second day after inoculation, with initial lesions appearing brown. By the third day, the entire plant had rotted and withered, while the control group showed no symptoms (Figure 2). Pathogenic bacteria was reisolated from the infected plants, confirming Koch’s postulates and the pathogenicity on tobacco. The Biolog system was used to test carbon source utilization and chemical sensitivity (Bochner B R. 1989). The pathogenic bacterium Biolog GEN III identification result showed 52 positive reactions, 25 negative reactions, and 17 borderline reactions. Among these, 36 carbon sources were utilized, including D-mannitol. Chemical sensitivity testing yielded 16 positive reactions and 2 negative reactions. According to the symptoms and morphological characteristics (Figure 3), the pathogen was tentatively identifed as Pectobacterium brasiliense. The molecular identification was performed by 16S rRNA primers (27F,5'-AGAGTTTGATCCTGGCTCAG-3';1492R,5'-GGTTACCTTGTTACGACTT-3') and gapA primers (gapA-7-F and gapA-938-R) (Yang et al. 2008) region sequencing. Sequences of 1506 and 932bp, respectively, were deposited in GenBank (accession numbers 16S: OQ519692; gapA: PV820694 ),The results showed that the similarity between the pathogen and P.brasiliense (16S: KY021041; gapA: OP793232) was 99.73% and 99.57%, respectively. A multigene phylogenetic tree was constructed based on 16S rRNA, repoS and gapA gene fragments using MEGA 7.0 Neighbor-Joining (NJ) with the sequences of homologous genes as well as Dickeya solani as an outgroup (Fig. 4),Based on plant disease symptoms, biochemical tests, and molecular sequencing, we conclude that this bacterial strain is P. brasiliense. To our knowledge, this is the frst report of P. brasiliense infecting tobacco in China. Reports indicate that this pathogen can infect 19 different plant species from 10 different families (Oulghazi et al. 2021). Occurrence of P. brasiliense on tobacco poses a potential threat to the health and yield of tobacco and other plants.

Tobacco (Nicotiana tabacum L.) has a propensity to accumulate cadmium (Cd), especially in its leaves, which can have a detrimental impact on yield, quality, and product safety. The development of low-accumulation cultivars is a vital mitigation approach; however, the underlying mechanisms remain inadequately understood. In this study, through pot experiments, the physiological mechanisms responsible for the differential Cd accumulation between the low-accumulating tobacco line CF986 and the high-accumulating Yuyan5 were explored. A comprehensive analysis was conducted on the organ-specific Cd distribution, chemical speciation, subcellular compartmentalization, and photosynthetic responses across a gradient of Cd exposure. In comparison with Yuyan5, CF986 accumulated significantly higher amounts of Cd in the roots and stems, but substantially lower amounts in the leaves. Specifically, the Cd content in the leaves of CF986 was only 64.32–68.74% of that in Yuyan5 across different Cd exposure levels. The organ-specific Cd distribution pattern in CF986 followed the order: leaf > stem > root. Moreover, the proportion of Cd partitioned to the leaves was lower in CF986 compared to Yuyan5, while the roots and stems exhibited enhanced Cd retention, with Cd levels in stems reaching up to 2.04 times higher than those in Yuyan5. Analysis of the chemical forms and subcellular distribution of Cd indicated that the mobile Cd fractions in the stems of CF986 were significantly reduced compared to Yuyan5. A larger proportion of Cd was immobilized in the stem cell-wall fraction, which enhanced Cd retention and restricted xylem-mediated transport to the leaves. Cd exposure did not significantly affect the concentration of foliar photosynthetic pigments in CF986; however, it notably inhibited the activity of the photosystem II (PSII) reaction center. At higher Cd levels, the photoprotective thermal dissipation gradually failed, with a decrease of up to 41.36% in ΦNO for CF986 compared to CK under Cd4.0 treatment. This research unveiled a stem barrier mechanism, whereby Cd translocation to the leaves is restricted through chemical and subcellular sequestration in the stem. This mechanism provides a novel perspective on both plant heavy metal allocation and the assurance of crop safety.