Flax (Linum usitatissimum L.) is a valuable crop that suffers significant losses due to Fusarium oxysporum f. sp. lini (Foln) infections. Apocarotenoids, especially volatiles have recently attracted attention as potential regulators of plant defence, but their functions remain poorly understood. Ionones exhibited concentration-dependent effects: low doses induced defence-related responses, including H₂O₂ accumulation and upregulation of defence-associated genes, whereas higher concentrations were phytotoxic. Foln infection was associated with increased ionone levels in planta, suggesting their involvement in plant responses to pathogen challenge. CCD inhibitor treatments altered H₂O₂ levels, ionone accumulation, and infection dynamics. Notably, similar patterns of H₂O₂ and ionone responses were observed in plants treated with selected inhibitors (B2 and D1) and during Foln infection. Overall, our findings indicate that ionones are unlikely to be effective fungicides, as their phytotoxic effects outweigh their limited impact on Foln infection. However, they appear to be associated with modulation of ROS levels and plant responses to pathogen challenge. Changes observed following CCD inhibition further point to coordinated redox-related processes, although their precise role in plant–pathogen interactions remains to be clarified.

Plants establish environmental connections through mycorrhizal symbiosis. These relationships enable them to obtain nutrients and cope with stress while simultaneously exchanging information through subterranean networks. A unified understanding of the molecular mechanisms underlying mycorrhizal interactions that drive adaptation and survival has not yet been achieved, in part because research on them stems from diverse fields of research, such as mycorrhizal ecology and plant epigenetics. This review presents recent studies demonstrating that epigenetic control serves as a central system enabling plants to adapt and maintain stable relationships with mycorrhizal fungi. We begin by describing different types of mycorrhizae. We then analyze mycorrhizal symbiosis by integrating plant and fungal genomic data with molecular evidence on DNA methylation, histone modification, chromatin remodeling, and small RNA pathways. We demonstrate that mycorrhizal symbiosis depends on changing chromatin states, which influence the regulation of the establishment, maintenance, and efficiency of symbiotic connections. They also regulate the balance between nutrient uptake and defense. They may underlie mycorrhizal stress and transgenerational “memory.” We review studies showing that RNA interference between different species enables reorganization of gene expression between plant and fungal cells. Finally, we identify key knowledge gaps and propose future research directions aimed at discovering reliable markers of mycorrhizal responses for epi-breeding and the development of climate-resilient agroecosystems.

The non-pathogenic strain of Fusarium oxysporum appears to be a very good priming agent, as by colonizing flax plants, it significantly limits the spread of the pathogenic strain of F. oxysporum (Foln), which is responsible for the most dangerous flax disease, Fusarium wilt. The priming mechanism involves local and systemic activation of pathogenesis-related genes and systemic activation of the antioxidant system, but whether this might be polyamine-dependent has not yet been determined. Therefore, our goal was to determine the role of polyamines in this mechanism. We demonstrated that treatment of flax plants with the endophytic F. oxysporum Fo47 strain resulted in a significant reduction in putrescine content. To confirm the importance of this polyamine in priming, we treated flax plants with putrescine and then infected them with Foln. We demonstrated that a constantly elevated putrescine content in the plants actually promoted infection. We then infected flax plants previously primed with Fo47 and those co-treated with Fo47 and Foln. We observed an increase in transcripts of the adc, odc, and dao genes in the initial days of infection, and a decrease in putrescine levels in the roots and shoots of plants primed with Fo47 compared to plants infected only with Foln and plants co-treated with Fo47 and Foln. In later days of infection, a significantly greater increase in transcripts of polyamine metabolism genes was observed in plants infected only with Foln, indicating significant progression of infection. In summary, the reduction in putrescine levels in plants is an important element of the priming process.

The Fusarium oxysporum species complex (FOSC) contains highly specific plant pathogens and some nonpathogenic strains, such as Fo47. Our work concentrated on F. oxysporum f.sp. lini (Foln), the specific flax pathogen and the endophytic strain F. oxysporum 47 (Fo47), which is suggested to have a protective effect on flax against pathogens. We investigated the effects of apocarotenoids, including ionones and abscisic acid (ABA), on the growth and development of these fungal strains, assessing the potential fungicidal properties of these compounds and comparing the responses of the fungi. The study demonstrated that ionones significantly inhibited mycelial growth in both Foln and Fo47 strains. Our results also showed the differences in apocarotenoid's effect on studied strains in regard of sporulation, FUB genes cluster activity and fusaric acid (FA) production.

IntroductionFlax (Linum usitatissimum) is an important industrial crop in temperate regions, but fungal diseases, especially those caused by Fusarium oxysporum sp. lini, pose a serious risk. These infections can lead to major crop losses, reducing interest in flax cultivation.MethodsThis study investigated the effects of exogenous spermidine (Spd) on the interactions between flax and Fusarium oxysporum sp. lini. Flax plants treated with either 10 mM or 100 mM Spd were monitored for changes in polyamine levels, gene expression, and hydrogen peroxide (H2O2) content following infection.Results and discussionNotably, plants treated with 10 mM Spd showed enhanced resistance, exhibiting better phenotypic health and lower fungal murein levels, especially in shoots. Chitinase expression in these plants remained similar to or lower than control levels, suggesting minimal additional defence activation was required. Additionally, a marked ROS burst occurred two days post-infection, followed by redox balance restoration, indicating a controlled defence response. These results suggest that moderate Spd treatment improves flax resilience against fusarium wilt while avoiding excessive defence activation, highlighting Spd’s potential for sustainable crop protection strategies.

Lignans are plant-derived biphenolic compounds with multiple hydroxyl groups, which, upon ingestion, are metabolized by gut microbiota into enterolignans—enterolactone and enterodiol. These mammalian metabolites exhibit structural similarity to estradiol, enabling lignans to modulate hormonal balance and exert estrogen-like effects. A growing body of evidence highlights their broad spectrum of health-promoting properties, including antioxidant, anti-inflammatory, and hormone-regulating effects. Lignans have shown potential in alleviating menopausal symptoms, preventing estrogen-dependent cancers, and mitigating conditions such as cardiovascular disease, diabetes, and metabolic syndrome. Additionally, their antimicrobial activity against bacteria, fungi, and viruses is being increasingly recognized. This review provides a comprehensive and up-to-date synthesis of current knowledge. It uniquely integrates the latest insights into lignan biosynthesis, gut microbiota-mediated metabolism, and clinically relevant outcomes. Importantly, this review incorporates recent findings from prospective cohort studies and meta-analyses and sheds light on emerging therapeutic applications, including antifungal activity—an area rarely covered in earlier literature. By presenting a holistic perspective, this review advances our understanding of lignans as multifaceted compounds with significant potential in preventive and therapeutic health strategies.

Research on Fusarium oxysporum f. sp. lini (Foln), a fungal pathogen of Linum usitatissimum L. (flax) responsible for significant crop losses, requires effective methods for visualizing fungus-plant interactions to improve understanding of this pathosystem. In this study, transgenic Foln strains expressing GFP or dsRed fluorescent markers were generated via Agrobacterium-mediated transformation. Several Agrobacterium tumefaciens strains were tested, and those with the highest transformation efficiency were selected. Transformants were screened based on phenotypic characteristics and further validated using molecular biology techniques. Since transgenesis can influence a fungus ' s ability to infect its host, the pathogenicity of the generated Foln lines was assessed by measuring the expression levels of pathogenesis-related genes and ROS metabolism-related genes, alongside quantifying O2- and H2O2 levels in the infected plant tissue. The presence of dsRed and GFP fluorescent markers was confirmed using fluorescence microscopy. Ultimately, two transformants exhibiting pathogenic characteristics similar to the wild-type Foln strain were selected. These transformants represent valuable tools for further studies of Foln pathogenesis in flax. Additionally, the workflow developed here can be adapted to generate fluorescent transformants of other F. oxysporum pathogenic strains.

Fungal infections of plants cause major losses in agriculture. Recent studies highlight the potential role of secondary metabolites including polyamines in improving plant defence against infections. This study examined the effect of exogenous cadaverine (Cad) on flax infections with Fusarium oxysporum f. sp. lini (Foln), using it as a priming factor to test whether increased Cad levels enhance resistance. It also explored how exogenous Cad and infection influence endogenous polyamines and their metabolism. The findings suggest that applying an appropriate amount of Cad to the medium reduces the development of flax fusariosis. According to phenotypic and molecular analyses, a concentration of 10 mM Cad was optimal. Excessive amounts of Cad (100 mM) in the substrate, and consequently in the plant, resulted in increased fungal content in plant shoots without changing phenotypic disease symptoms and significantly altered polyamine content, the expression of polyamine metabolism genes, and induced oxidative stress. Plants treated with 10 mM Cad followed by Foln during early colonisation stages had lower fungal presence in both roots and shoots. This reduction may be due to inhibited fungal growth in the substrate and restricted root penetration in plants with elevated Cad levels. Additionally, altered polyamine metabolism and levels of other polyamines could contribute to limiting disease progression. Therefore, Cad plays an important role in plant-fungus interactions and holds promise for enhancing flax resistance to fusariosis.

Despite its numerous applications, flax fiber utilization is limited by time-consuming extraction largely determined by pectin content. To address this, transgenic flax plants with reduced pectin levels were generated to facilitate fiber release. We evaluated how pectin reduction affects plant growth, fiber composition, and properties. Field cultivation showed that low-pectin lines exhibited a phenotype comparable to the control. Fibers from these plants contained significantly less pectin and hemicellulose and accumulated more cellulose. These changes were accompanied by conformational and spatial reorganization of the cell wall structure. As a result, fibers with reduced pectin demonstrated improved tensile strength (by 45,6% and by 61,5% for PGI11 and RHA7 fibers, respectively) and enhanced binding capacity for therapeutic substances. Our results support the hypothesis of a compensatory mechanism between pectin and cellulose, where a decrease in one component is offset by an increase in the other. Furthermore, we show that structural reorganization induced by pectin reduction improves the mechanical properties and functional potential of flax fibers. This study highlights that targeted modification of pectin content can enhance fiber quality and functionality without adverse effects on plant growth, offering a promising strategy for optimizing flax for industrial and biomedical applications.

Background: Flax (Linum usitatissimum L.) is an economically important crop that is highly susceptible to Fusarium oxysporum f. sp. lini (Foln). While phytohormones are key regulators of defence, their interaction with polyamines during infection remains poorly understood. This study aimed to characterise hormonal dynamics in flax under Foln infection and the modulatory role of spermidine (Spd). Methods: Targeted UPLC–MS/MS profiling quantified over 30 hormone-related compounds, including auxins, cytokinins, gibberellins, jasmonates, salicylic acid, and abscisic acid, in shoots and roots of healthy, infected, and Spd-treated plants. Two Spd concentrations (10 and 100 mM) were applied under controlled in vitro conditions. Results: Foln infection triggered tissue- and time-specific hormonal shifts, with early activation of jasmonate and auxin metabolism in shoots and later accumulation of salicylic acid and gibberellins in roots. Spd, particularly at 10 mM, reshaped these responses by reinforcing cytokinin and salicylic acid responses, stabilising auxin homeostasis, and enhancing jasmonate and abscisic acid responses. Conclusions: Spermidine coordinates hormone crosstalk, enabling balanced and efficient defence activation. The results highlight its potential as a priming agent enhancing flax resilience to F. oxysporum.

Flax (Linum usitatissimum) is a valuable industrial crop in temperate climate zones. However, the prevalence of fungal diseases, particularly those caused by Fusarium oxysporum sp. linii, poses a substantial threat, leading to significant crop losses and diminished interest in flax cultivation. In this study, flax plants were treated with spermidine and subsequently infected with Fusarium oxysporum to investigate multiple aspects: (1) the uptake of exogenous spermidine by the plants, (2) the impact of this uptake on the levels of other polyamines and the expression of polyamine biosynthesis genes, and (3) the effects of fungal infection on these parameters. The results demonstrated that flax plants effectively absorb spermidine, leading to substantial changes in the levels of polyamines and the expression of related genes in both roots and shoots. Notably, spermidine treatment resulted in significant alterations in the levels of putrescine and spermine, as well as in the transcript levels of key genes involved in polyamine biosynthesis. Moreover, Fusarium oxysporum infection itself induced changes in polyamine content and gene expression, which varied between root and shoot tissues. When spermidine-treated plants were infected with Fusarium oxysporum, a more complex response was observed, characterized by modifications in polyamine levels and gene expression that suggest an enhanced defense mechanism against the pathogen. These findings indicate that polyamine treatment not only affects the infection process but also modulates the plant's internal polyamine metabolism and gene expression, contributing to an improved resistance to fungal attack. This study highlights the potential of spermidine as a protective agent in flax and provides a foundation for further exploration of polyamine-related defense mechanisms.

IntroductionFlax (Linum usitatissimum) is a crop producing valuable products like seeds and fiber. However, its cultivation faces challenges from environmental stress factors and significant yield losses due to fungal infections. The major threat is Fusarium oxysporum f.sp lini, causing fusarium wilt of flax. Interestingly, within the Fusarium family, there are non-pathogenic strains known as biocontrols, which protect plants from infections caused by pathogenic strains. When exposed to a non-pathogenic strain, flax exhibits defense responses similar to those seen during pathogenic infections. This sensitization process activates immune reactions, preparing the plant to better combat potential pathogenic strains. The plant cell wall is crucial for defending against pathogens. It serves as the primary barrier, blocking pathogen entry into plant cellsMethodsThe aim of the study was to investigate the effects of treating flax with a non-pathogenic Fusarium oxysporum strain, focusing on cell wall remodeling. The infection’s progress was monitored by determining the fungal DNA content and microscopic observation. The plant defense response was confirmed by an increase in the level of Pathogenesis-Related (PR) genes transcripts. The reorganization of flax cell wall during non-pathogenic Fusarium oxysporum strain infection was examined using Infrared spectroscopy (IR), determination of cell wall polymer content, and analysis of mRNA level of genes involved in their metabolism.Results and discussionIR analysis revealed reduced cellulose content in flax seedlings after treatment with Fo47 and that the cellulose chains were shorter and more loosely bound. Hemicellulose content was also reduced but only after 12h and 36h. The total pectin content remained unchanged, while the relative share of simple sugars and uronic acids in the pectin fractions changed over time. In addition, a dynamic change in the level of methylesterification of carboxyl groups of pectin was observed in flax seedlings treated with Fo47 compared to untreated seedlings. The increase in lignin content was observed only 48 hours after the treatment with non-pathogenic Fusarium oxysporum. Analysis of mRNA levels of cell wall polymer metabolism genes showed significant changes over time in all analyzed genes. In conclusion, the research suggests that the rearrangement of the cell wall is likely one of the mechanisms behind flax sensitization by the non-pathogenic Fusarium oxysporum strain. Understanding these processes could help in developing strategies to enhance flax’s resistance to fusarium wilt and improve its overall yield and quality.

Polyamines are low molecular weight amines that serve numerous pivotal functions in eukaryotic cells, such as contributing to processes like embryogenesis, organogenesis in plants, and host interactions in fungi. Over the years, there has been significant interest in these compounds concerning the enhancement of plant resistance to pathogenic infections. As polyamines play indispensable roles in both plant and fungal functionalities, elucidating their precise significance in the interplay between these two organisms remains intricate. Furthermore, it is becoming evident that polyamines can yield disparate effects contingent upon factors such as prevailing conditions, concentrations, and the specific species of both plants and fungi. This paper provides an analysis of recent research conducted mostly within the last five years, concentrating on the multifaceted role of polyamines in the dynamic between plants and two types of fungi: phytopathogenic and mycorrhizal. The investigation places particular emphasis on two principal aspects. Firstly, it delves into the influence of polyamines on fungal pathogens, encompassing aspects such as mycotoxin production and the infection process. Secondly, it explores the intricate interplay of the plant's immune response to fungal pathogens.

Beta-ketothiolases are involved in the beta-oxidation of fatty acids and the metabolism of hormones, benzenoids, and hydroxybutyrate. The expression of bacterial beta-ketothiolase in flax (Linum usitatissimum L.) results in an increase in endogenous beta-ketothiolase mRNA levels and beta-hydroxybutyrate content. In the present work, the effect of overexpression of beta-ketothiolase on retting and stem and fibre composition of flax plants is presented. The content of the components was evaluated by high-performance liquid chromatography, gas chromatography–mass spectrometry, Fourier-transform infrared spectroscopy, and biochemical methods. Changes in the stem cell walls, especially in the lower lignin and pectin content, resulted in more efficient retting. The overexpression of beta-ketothiolase reduced the fatty acid and carotenoid contents in flax and affected the distribution of phenolic compounds between free and cell wall-bound components. The obtained fibres were characterized by a slightly lower content of phenolic compounds and changes in the composition of the cell wall. Based on the IR analysis, we concluded that the production of hydroxybutyrate reduced the cellulose crystallinity and led to the formation of shorter but more flexible cellulose chains, while not changing the content of the cell wall components. We speculate that the changes in chemical composition of the stems and fibres are the result of the regulatory properties of hydroxybutyrate. This provides us with a novel way to influence metabolic composition in agriculturally important crops.

Fusarium culmorum is a ubiquitous soil pathogen with a wide host range. In flax (Linum ussitatissimum), it causes foot and root rot and accumulation of mycotoxins in flax products. Fungal infections lead to huge losses in the flax industry. Moreover, due to mycotoxin accumulation, flax products constitute a potential threat to the consumers. We discovered that the defense against this pathogen in flax is based on early oxidative burst among others. In flax plants infected with F. culmorum, the most affected genes are connected with ROS production and processing, callose synthesis and ABA production. We hypothesize that ABA triggers defense mechanism in flax and is a significant player in a successful response to infection.

Metastatic colorectal cancer (CRC) remains a hard-to-cure neoplasm worldwide. Its curability declines with successive lines of treatment due to the development of various cancer resistance mechanisms and the presence of colorectal cancer stem cells (CSCs). Celastrol and resveratrol are very promising phytochemicals for colon cancer therapy, owing to their pleiotropic activity that enables them to interact with various biological targets. In the present study, the anticancer activities of both compounds were investigated in metastatic colon cancer cells (LoVo cells) and cancer stem-like cells (LoVo/DX). We showed that celastrol is a very potent anti-tumor compound against metastatic colon cancer, capable of attenuating CSC-like cells at the molecular and cellular levels. In contrast, resveratrol has a much greater effect on colon cancer cells that are expressing standard sensitivity to anticancer drugs, than on CSC-like cells. In addition, both polyphenols have different influences on the expression of SIRT genes, which seems to be at least partly related to their anti-tumor activity.

This review was designed to summarize the present state of research around the genetic and epigenetic modification of selected plant species and the potential for their application in industry. This review summarizes the activity of research groups from the University of Wrocław completed over the last 3 decades which tends to focus on potatoes and flax likely as a result of their centuries-old tradition of cultivation, processing, and use in Poland. The aims of these studies were various and included the creation of pathogen-resistant plants, increased antioxidant production, improved flax fiber quality, and improved oil properties. New plant breeds initially produced using genetic engineering technology provide an excellent basis for improving our understanding of the genes involved in potato and flax productivity and the quality of their products. These results have been published in many papers and have given rise to new methods for plant breeding and product prototypes which have been patented. However, none of the prototypes have been commercialized because of their GMO origins. In addition, later development of a novel, epigenetic method has led to the creation of more diverse products based on the newly obtained variety of flax called Silesia. These developments have facilitated the production of a range of new raw materials from these epigenetically modified plants. These include a modified oil for improved nutrition and regeneration of skin cells, seed- cake extracts that act as anti-infection agents, improved fiber production for use as bandages for chronic wounds, improved fibers for application as bio composite materials for the development of biodegradable packaging materials and scaffolds for tissue engineering, and micronized fiber for drug delivery. These modifications mean that flax has become a more useful and valuable source of a wide range of raw materials applicable in industry, allowing for the application of these materials in zero waste applications.

Diet bioactive components, in the concept of nutrigenetics and nutrigenomics, consist of food constituents, which can transfer information from the external environment and influence gene expression in the cell and thus the function of the whole organism. It is crucial to regard food not only as the source of energy and basic nutriments, crucial for living and organism development, but also as the factor influencing health/disease, biochemical mechanisms, and activation of biochemical pathways. Bioactive components of the diet regulate gene expression through changes in the chromatin structure (including DNA methylation and histone modification), non-coding RNA, activation of transcription factors by signalling cascades, or direct ligand binding to the nuclear receptors. Analysis of interactions between diet components and human genome structure and gene activity is a modern approach that will help to better understand these relations and will allow designing dietary guidances, which can help maintain good health.

In this study transcriptome was analyzed on two fibrous varieties of flax: the susceptible Regina and the resistant Nike. The experiment was carried out on 2-week-old seedlings, because in this phase of development flax is the most susceptible to infection. We analyzed the whole seedlings, which allowed us to recognize the systemic response of the plants to the infection. We decided to analyze two time points: 24h and 48h, because our goal was to learn the mechanisms activated in the initial stages of infection, these points were selected based on the previous analysis of chitinase gene expression, whose increase in time of Fusarium oxysporum lini infection has been repeatedly confirmed both in the case of flax and other plant species. The results show that although qualitatively the responses of the two varieties are similar, it is the degree of the response that plays the role in the differences of their resistance to F. oxysporum.