Search Results (385)

High temperature stress severely compromises plant growth and productivity by triggering chlorophyll loss. Plant protochlorophyllide-dependent translocon component of 52 kDa (PTC52) has been proven to be involved in chlorophyll biosynthesis, yet its functional role in plant high-temperature stress response remains uncharacterized. In our study, PlPTC52 was isolated and characterized from herbaceous peony (Paeonia lactiflora Pall.), an economically important ornamental species susceptible to high temperature stress. The PlPTC52 gene comprised a 1647 bp coding sequence that translates into a 548-amino-acid protein. Subcellular localization confirmed its chloroplast localization, consistent with its putative role in chlorophyll biosynthesis. Functional analyses showed that silencing of PlPTC52 in P. lactiflora accelerated chlorophyll loss, increased reactive oxygen species accumulation, and impaired photosystem II efficiency and membrane integrity under high temperature stress. Conversely, overexpression of PlPTC52 in Nicotiana tabacum decelerated chlorophyll loss, decreased reactive oxygen species accumulation, and improved photosystem II efficiency and membrane integrity under high temperature stress. Collectively, this study provides the first functional evidence implicating PTC52 in plant responses to high temperature stress and identifies PlPTC52 as a potential genetic resource for enhancing thermotolerance in horticultural crops. Full article

Phospholipid:Diacylglycerol Acyltransferase (PDAT) catalyzes the final step of the acyl-CoA-independent triacylglycerol (TAG) biosynthesis pathway and plays an important role in lipid metabolism and abiotic stress responses in plants. Oat (Avena sativa L.) possesses the highest lipid content among cereal crops, yet the functions of PDAT genes in this species remain largely unexplored. In this study, we identified and characterized three AsPDAT genes in oat, which form a homeologous triplet evenly distributed across the three subgenomes and show high conservation in sequence and gene structure. Phylogenetic analysis indicated a clear divergence between monocot and dicot PDATs. Expression profiling revealed that the three AsPDAT genes share similar organ-specific and stress-responsive expression patterns, suggesting functional conservation following polyploidization, with AsPDAT-5C showing relatively higher transcript levels. The enzymatic activity of AsPDAT-5C was confirmed by complementation of the TAG-deficient yeast quadruple mutant H1246. Transient expression in Nicotiana benthamiana epidermal cells demonstrated that AsPDAT-5C localizes to the endoplasmic reticulum. Stable overexpression of AsPDAT-5C in Nicotiana tabacum significantly increased lipid content in both leaves and seeds without compromising plant growth and enhanced tolerance to cold and phosphorus-deficiency stresses. Our results provide new insights into the AsPDAT gene family and underscore the potential of AsPDAT-5C in engineering lipid biosynthesis and improving stress resilience in plants. Full article

The tea plant (Camellia sinensis) employs inducible chemical defenses against insect herbivores, yet the role of phenylalanine ammonia-lyase (PAL) in this process remains inadequately characterized. This study demonstrates that PAL is essential for tea plant’s direct resistance against the tea geometrid (Ectropis grisescens Warren). Inhibition of PAL activity using 2-Aminoindan-2-phosphonic acid significantly reduced catechins accumulation and promoted larval growth of E. grisescens. Compared to mechanical wounding alone, simulated herbivory feeding (mechanical wounding plus oral secretions) induced higher PAL activity and more pronounced upregulation of CsPAL genes. This response specifically highlighted CsPALb, CsPALd, and CsPALe as core, herbivore-responsive members. Transient silencing of CsPALb in tea leaves led to a significant reduction in the levels of catechin (-)-epigallocatechin and epigallocatechin gallate. Moreover, heterologous overexpression of CsPALb and CsPALd in tobacco (Nicotiana tabacum) enhances resistance to Spodoptera litura. Our results indicate that PAL-mediated phenylpropanoid metabolism is not only critical for herbivore resistance of tea plant, but can also provide valuable gene resources for improving herbivore resistance in other plants. Full article

Drought and salinity are critical abiotic stresses that constrain plant growth. Although MYB transcription factors mediate plant responses to abiotic stresses, their functions in the monocot I. laevigata remain unexplored. Here, we identified a nuclear-localized gene, IlMYB108, which was rapidly upregulated under NaCl and PEG-6000 treatments. Overexpression of IlMYB108 in tobacco enhanced root growth under salt and drought conditions. At the seedling stage, transgenic lines maintained higher leaf growth rates and plant height with reduced wilting during 14 days of continuous stress. Physiologically, transgenic plants exhibited a higher net photosynthetic rate (Pn), maximum photochemical efficiency of photosystem II (Fv/Fm), and chlorophyll content, alongside lower stomatal conductance (Gs), intercellular CO₂ concentration (Ci), and transpiration rate (Tr). They also accumulated less malondialdehyde (MDA), superoxide anion (O₂⁻), and hydrogen peroxide (H₂O₂), which was attributed to enhanced activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), as confirmed by p-Nitro-Blue tetrazolium chloride (NBT) and 3,3′-diaminobenzidine tetrahydrochloride (DAB) staining. Moreover, IlMYB108 up-regulated stress-responsive and antioxidant genes. Collectively, IlMYB108 functions as a key gene that enhances tobacco tolerance to salt and drought stress by coordinating root development, photosynthetic efficiency, water balance and antioxidant defense, thereby providing a valuable genetic resource for breeding stress-resilient plants. Full article

Pollen tube growth entails complex molecular interactions between the cytoskeletal apparatus and membrane trafficking. Tip growth involves polarized distribution of proteins and lipids along the plasma membrane, including liquid-ordered microdomains, rich in sterols and sphingolipids (lipid rafts), in the apical/subapical region of tobacco pollen tubes. Intriguingly, biochemical characterization of detergent-insoluble membranes purified from tobacco pollen tubes revealed the presence of both actin and tubulin. Here, we report that inhibition of sterol biosynthesis altered lipid rafts and lowered the association of tubulin with detergent-insoluble membranes. Our results showed that sterol depletion increased the number of microtubules in the subapical region, altered microtubule distribution and affected microtubule bundling activity. Oryzalin washout experiments also suggested that lipid-ordered domains could play a role in regulating microtubule nucleation/regrowth. Full article

Axillary buds are key organs that determine shoot branching and aerial architecture in plants and critically influence crop growth and productivity. Understanding the molecular mechanisms underlying the transition from dormancy to bud activation is a central question in plant developmental regulation. Although previous studies have revealed post-release developmental processes, the early regulatory network that triggers dormancy release remains unclear. In this study, we used tobacco (Nicotiana tabacum) as a model and focused on transcriptomic changes of regulatory factors in axillary buds within 36 h after decapitation. Then, we systematically analyzed key molecular events that induce dormancy release. The results revealed the involvement of diverse signals in decapitation-induced bud activation, including key plant hormones like auxin, cytokinin, and gibberellin; as well as external cues such as sugar, nitrogen, and light. Significant changes occurred as early as 0.5 to 1 h after decapitation. Among these, auxin and sugar signaling played central roles in initiating dormancy release. In addition, various signaling factors exhibited coordinated regulatory effects during the continued development of activated buds. Functional validation further demonstrated that EXB1 and STM, two key regulators of axillary bud initiation, participated in the subsequent stages of branch development. In conclusion, our study reveals that decapitation-induced dormancy release of axillary buds occurs at a very early stage (0.5–1 h). This rapid response is driven by a complex regulatory network involving multiple hormones and metabolic signals. These findings provide new molecular insights into the dynamic regulatory balance of axillary bud development. They also establish a theoretical basis and strategic reference for trait regulation and modular breeding design. Full article

The current investigation involved preliminary laboratory research regarding the accumulation capacity of three types of hyperaccumulator plants when specific soil factors are altered during their cultivation. Three different plants participated in this experiment, namely, milk thistle (Silybum marianum (L.) Gaerth), industrial hemp (Cannabis sativa L.), and tobacco (Nicotiana tabacum L.), which were cultivated in two soils with different pH values, yet containing similar levels of metal pollutants. ABC fire extinguisher powder (FP), which had been tested in the past and found to cause a significant change in nutrient availability, was added to the soils. The FP was added at 1% v/v and, in order to facilitate its fast incorporation into the soil, the soil moisture was maintained at 60–65%. The experiment was conducted in pots where the plants were grown in contaminated soils, with and without the FP addition. The pseudo-total (after extraction with Aqua Regia), available (after extraction with DTPA), and water-soluble concentrations (after extraction with CaCl₂ solution) of Cd, Cr, and Cu were determined in the soils. The plants completed their growth cycle (in 112, 128, and 139 days, respectively), were harvested, and the metal concentrations were assessed after extraction with Aqua Regia, both in the underground and above-ground parts. FP addition caused a significant decrease in the availability of each of the three metals, yet mainly Cr, as it caused a maximum reduction of 19.6% and 16.0% in the rate of water-soluble and available (after extraction with DTPA) Cr, respectively, in relation to the total Cr concentration in acidic soil, revealing the decisive role played by soil reaction in metal availability. FP addition caused a significant Cd reduction in accumulation in the above-ground parts of cultivated plants in the order of hemp > thistle > tobacco. FP use appears to significantly alter the plant-to-soil metal transfer, affecting the plants’ ability to accumulate Cd, Cr, and Cu. Apparently, this material, disposed of in the environment, could be a useful and low-cost soil conditioner, in line with the principles of the circular economy. Full article

Somatic embryogenesis (SE) is a morphogenetic pathway widely employed in the commercial micropropagation of plants. This route enables the generation of somatic embryos from somatic tissues, which give rise to complete (bipolar) plants that develop like zygotic embryos. SE can proceed via direct or indirect pathways, and both approaches have been adapted not only for large-scale clonal propagation but also for the regeneration of genetically modified plants. In this context, SE can be harnessed as a versatile platform for recombinant protein production, including vaccine antigens and therapeutic proteins, by combining plant tissue culture with genetic transformation strategies. Successful examples include non-model plants, as Daucus carota and Eleutherococcus senticosus expressing the cholera and heat-labile enterotoxin B subunits, respectively; Oryza sativa, Nicotiana tabacum, and Medicago sativa producing complex proteins such as human serum albumin (HSA), α₁-antitrypsin (AAT), and monoclonal antibodies. However, challenges remain in optimizing transformation efficiency, scaling up bioreactor-based suspension cultures, and ensuring proper post-translational modifications under Good Manufacturing Practice (GMP) standards. Recent advances in synthetic biology, modular vector design, and glycoengineering have begun to address these limitations, improving control over transcriptional regulation and protein quality. This review highlights the application of SE as a biotechnological route for recombinant protein production, discusses current challenges, and presents innovative strategies and perspectives for the development of sustainable plant-derived biopharmaceutical systems. Full article

Acyl-CoA-binding proteins (ACBPs) possess a conserved acyl-CoA-binding (ACB) domain that facilitates binding to acyl-CoA esters. In addition to their typical role in lipid metabolism, plant ACBPs have been shown to participate in various physiological processes, such as membrane biogenesis, stress response pathways and plant immunity mechanisms. Here, we identified five PutACBP members in alkaligrass (Puccinellia tenuiflora), which were divided into four distinct classes based on a phylogenetic tree constructed from 86 ACBP genes from 12 plant species. Promoter analysis identified numerous cis-acting elements linked to abiotic stresses (e.g., light, drought, heat, and cold) and hormone responses. Expression profile analyses revealed that PutACBPs exhibit broad expression patterns across many organs and respond to salinity-alkali, cold, H₂O₂, and CdCl₂ stresses. Transient expression of five PutACBP-GFPs in tobacco (Nicotiana tabacum) revealed PutACBP1 and PutACBP2 localized to the plasma membrane, cytoplasm, and cell nucleus, while PutACBP3, PutACBP4, and PutACBP5 localized around the plasma membrane and cytoplasm. Furthermore, heterologous constitutive expression of PutACBP3 in Arabidopsis (Arabidopsis thaliana) enhanced the resistance of transgenic plants to salinity stress, possibly through alterations in the levels of lipid metabolism-related and stress-responsive genes. The ACBP gene family is highly conserved across different plant species. This study provides the first comprehensive genomic and functional characterization of the PutACBP family in alkaligrass, elucidating its evolutionary conservation, phylogenetic classification, and stress-response roles. Notably, overexpression of PutACBP3 in Arabidopsis significantly enhanced salt tolerance, suggesting its critical function in salt-stress adaptation in alkaligrass. Full article

Background/Objectives: Nicotine is a naturally occurring alkaloid primarily found in Nicotiana tabacum. This phytochemical is well known for its addictive properties, and its consumption—particularly through tobacco smoking—is strongly associated with an increased risk of malignancies, metabolic dysfunctions, and cardiovascular as well as respiratory diseases. Despite these adverse effects, several studies have also reported beneficial actions of nicotine, including the enhancement of cognitive functions in several neurodegenerative diseases. Methods: To better elucidate the multiple effects of nicotine and clarify their underlying mechanisms, we performed an NMR-based metabolomic analysis of SH-SY5Y neuroblastoma cells exposed to nicotine action. Results: Our results indicate that nicotine modulates mitochondrial function and membrane turnover, thereby influencing mitochondrial bioenergetics, synaptic plasticity, and connectivity. Conclusions: Collectively, these findings may contribute, at least in part, to explaining the neuroprotective effects of nicotine described in preclinical models of neurodegenerative disease. Full article

The short peptide AlaGluAspLeu (AEDL) stimulates shoot and root development in Nicotiana tabacum. Growing tobacco in the presence of AEDL was found to induce autophagy and programmed cell death, as demonstrated using immunodetection of the autophagy marker ATG8 and cytochrome c in the cytoplasm, as well as the detection of DNA breaks using the TUNEL assay. A detailed study of the ultrastructure of Nicotiana tabacum root cells grown in the presence of AEDL using transmission electron microscopy revealed fundamental structural differences from control cells. Control cells contained only lytic vacuoles, while in the presence of AEDL, tobacco root meristem cells contained predominantly protein-storing vacuoles and amyloplasts with numerous starch granules in the stroma. Characteristic types of phagophores were identified, forming numerous small autophagosomes with cytoplasmic regions, multivesicular bodies, or concentric membranes, possibly with cytoskeletal elements. Expression of autophagy protein genes revealed a decrease in TOR expression, which promoted autophagy activation and prevented ATG13 phosphorylation. ATG8 gene expression significantly increased in the presence of the AEDL peptide. Schematic diagrams of autophagy processes in root cells of control plants and those grown in the presence of AEDL are presented. Based on these data, it was concluded that stimulation of tobacco plant development in the presence of the AEDL peptide at a concentration of 10⁻⁷ M occurs due to the activation of metabolic processes and autophagy. Moreover, the synthesis of metabolites exceeds the required amount of nutrients, which accumulate in vacuoles and leucoplasts. Full article

Drastic changes in temperature, salinity of soils and drought are some of the most studied abiotic stressors in important crops. Plants have developed various biochemical mechanisms to counteract these conditions. Transcription factors play a significant role in regulating stress responses. Previously, in our lab, it was identified that the CpRap2.4a protein, which belongs to the AP2/ERF superfamily, is related to the response to abiotic stress from extreme temperature, and confers thermal tolerance to Carica papaya CV. This study presents a randomized experimental strategy for the analysis of the physiological and biochemical responses of Nicotiana tabacum plants subjected to heat stress, and how the foliar application of the recombinantly expressed CpRap2.4a can modulate beneficial responses. Plants subjected to heat stress present a healthier physiology, as clearly shown by biochemical parameters. Moreover, physiological parameters also suggest an improvement of heat tolerance compared with the control group. Scanning electron microscopy suggests that stomatal aperture and conductance are the key mechanisms for how recombinantly expressed CpRap2.4a can act as a regulatory player to heat stress. Full article

Isoflavone synthase (IFS) is the key enzyme in isoflavonoid biosynthesis and has been functionally characterized in numerous plant species. Glycyrrhiza species, valued for their medicinal properties, accumulate flavonoids with significant physiological activities. Among these, isoflavones play crucial roles in plant growth, development and stress responses. However, the IFS gene family in Glycyrrhiza remains poorly understood. In this study, we identified 10, 9 and 9 IFS genes in G. uralensis, G. inflata and G. glabra, respectively. Phylogenetic analysis classified these genes into four distinct clades (Clade A–D). Further characterization included chromosomal localization, gene structure, conserved motifs, cis-acting elements and synteny analysis. Using yeast one-hybrid (Y1H) screening, dual-luciferase assays and an electrophoretic mobility shift assay (EMSA), these results revealed that auxin response factor 4 (GgARF4) directly binds to the isoflavone synthase 9 (GgIFS9) promoter and activates its expression. Following indole-3-acetic acid (IAA) treatment, RNA-seq revealed that in the differentially expressed genes (DEGs), the genes involved in isoflavonoid and flavonoid biosynthesis pathways were significantly enriched. The result of quantitative reverse transcription polymerase chain reaction (qRT-PCR) revealed that GgIFS9 was strongly induced by IAA. β-Glucuronidase (GUS) assays confirmed that IAA activates the expression of the GgIFS9 promoter in Nicotiana tabacum. Our findings reveal that, through GgARF4 and its downstream-activated gene GgIFS9, IAA may promote flavonoid synthesis in G. glabra. This study provides novel insights into the auxin-mediated regulation of secondary metabolism in Glycyrrhiza species. Full article

A sustainable economy and the drive to reduce agro-industrial waste worldwide motivate the increased interest in alternative uses of traditionally cultivated plants such as tobacco. Tobacco seeds are an underutilized resource with enormous potential for application in various areas of human life. The present study aims to characterize the phytochemical composition and nutritional potential of Oriental tobacco seeds grown in Bulgaria, in order to support their possible application in areas outside the tobacco industry. Two Oriental tobacco varieties (“Krumovgrad 90” and “Krumovgrad 58”) from three production regions were explored and comparatively evaluated in terms of their physical and chemical indicators, determined by standardized methods. The results showed high protein (22.57–23.84%) and energy content (482–531 kcal/100 g), combined with relatively low carbohydrate levels (3.79–4.03%) and the presence of bioactive compounds, such as polyphenols (288–357 mg GAE/100 g). The seeds contained significant amount of oil (36.31–39.24%), of which the fatty acid profile included 16 identified components, with linoleic (72.0–74.4%), oleic (11.2–13.5%), palmitic (9.6–10.2%), and stearic (1.8–2.5%) acids taking the greatest share. The sterol fraction was dominated by β-sitosterol (43.5–46.8%), followed by sitostanol, campesterol and stigmasterol, with a stable distribution between the samples. The main tocol was γ-tocotrienol (56.5–61.4%), with α-tocotrienol being detected only in one of the varieties (“Krumovgrad 58”, 13.3%). The phospholipid fraction showed variations between the samples, with a dominant presence of phosphatidylinositol (18.0–20.4%). The results from the study confirmed the tangible potential of tobacco seeds as a source of biologically active substances in the development of functional foods and dietary supplements. Full article

Drought stress is a major limiting factor during the process of plant growth and development, especially in arid and semi-arid regions. MYB transcription factors play vital roles in the regulation of many developmental processes under various stresses. The aim of this study was to determine whether PtrMYB119 enhanced dehydration tolerance in Nicotiana tabacum. PtrMYB119, with a weak transactivation activity, was distributed throughout the cell with no apparent specificity. The transgenic tobacco overexpressing PtrMYB119 might regulate dehydration tolerance through increased ABA content and antioxidant enzyme activities, decreased MDA levels, and up-regulation of antioxidant genes, polyamine biosynthesis genes, and drought-responsive genes. Overall, our results could contribute to the elucidation of drought tolerance underlying PtrMYB119 action in tobacco and indicated that PtrMYB119 could be exploited for engineering drought-enduring plants in the future. Full article