Search Results (19)

Plants are subjected to various stresses during the growth process, including biotic stresses, as well as abiotic stresses such as temperature, drought, salt, and heavy metals. To cope with these biotic and abiotic adversities, plants have evolved complex regulatory mechanisms during their long-term environmental adaptations. In a suddenly changing environment, protein modifiers target other proteins to induce post-translational modification (PTM) in order to maintain cell homeostasis and protein biological activity in plants. PTMs modulate the activity of enzymes and transcription factors in their respective metabolic pathways, enabling plants to produce essential compounds for their survival under stress conditions. Examples of post-translational mechanisms include phosphorylation, ubiquitination, glycosylation, acetylation, protein–protein interactions, and targeted protein degradation. Furthermore, the role of histone modifications in regulating secondary metabolism deserves attention due to its potential impact on heritability and its contribution to stress tolerance. Understanding the epigenetic aspect of these modifications can provide valuable insights into the mechanisms underlying stress response. In this context, also examining PTMs that impact the biosynthesis of secondary metabolites is meaningful. Secondary metabolites encompass a wide range of compounds such as flavonoids, alkaloids, and terpenoids. These secondary metabolites play a crucial role in plant defense against herbivores, pathogens, and oxidative stress. In this context, it is imperative to understand the contribution of secondary metabolism to plant tolerance to abiotic stresses and how this understanding can be leveraged to improve long-term survival. While many studies have focused on the transcriptional regulation of these metabolites, there is a growing interest in understanding various changes in PTMs, such as acetylation, glycosylation, and phosphorylation, that are able to modulate plants’ response to environmental conditions. In conclusion, a comprehensive exploration of post-translational mechanisms in secondary metabolism can enhance our understanding of plant responses to abiotic stress. This knowledge holds promise for future applications in genetic improvement and breeding strategies aimed at increasing plant resilience to environmental challenges. Full article

Alternaria panax, the primary pathogen that causes ginseng Alternaria leaf blight disease, can lead to a 20–30% reduction in ginseng yield. WD40 repeat-containing proteins are evolutionarily conserved proteins with diverse functions between different organisms. In this study, we characterized the roles of a WD40 repeat-containing protein in A. panax. The deletion of ApWD40a impaired the mycelial growth, reduced the sporulation, and significantly decreased the efficiency in utilizing various carbon sources. The ΔApwd40a mutant showed increased sensitivity to osmotic stress and metal ion stress induced by sorbitol, NaCl, and KCl, but decreased the sensitivity to a cell wall stress factor (SDS) and oxidative stress factors (paraquat and H₂O₂). Pathogenicity assays performed on detached ginseng leaves and roots revealed that the disruption of ApWD40a significantly decreased the fungal virulence through attenuating melanin and mycotoxin production by A. panax. A comparative transcriptome analysis revealed that ApWD40a was involved in many metabolic and biosynthetic processes, including amino acid metabolism, carbon metabolism, sulfate metabolic pathways, and secondary metabolite pathways. In particular, a significantly upregulated gene that encoded a sulfate permease 2 protein in ΔApwd40a, named ApSulP2, was deleted in the wild-type strain of A. panax. The deletion of ApSulP2 resulted in reduced biomass under sulfate-free conditions, demonstrating that the sulfate transport was impaired. Taken together, our findings highlight that ApWD40a played crucial roles in different biological processes and the pathogenicity of A. panax through modulating the expressions of genes involved in various primary and secondary metabolic processes. Full article

Background/Objectives: This study evaluates the effect of Mn(II) and Co(II) ions on the production of anti-Candida metabolites by the endophytic fungus Aspergillus sp., isolated from Dizygostemon riparius. The objective was to identify metal-induced secondary metabolites with antifungal potential against drug-resistant Candida species. Methods: Aspergillus sp. was cultivated in Czapek agar supplemented with MnCl₂ (400 µM) or CoCl₂ (200 µM). Metabolite profiles were analyzed using UHPLC-DAD and LC-ESI-HRMS, followed by structural elucidation via NMR. Antifungal and biofilm inhibition activities were tested against Candida albicans and Candida parapsilosis. Toxicity was assessed using Tenebrio molitor larvae. Results: Key metabolites, including pyrophen, penicillquei B, and fonsecinone B, demonstrated antifungal activity with MIC values of 4.37–280.61 µg/mL. Fonsecinone B exhibited superior biofilm inhibition, surpassing fluconazole in reducing biofilm biomass and viability. In vivo assays showed low toxicity, with survival rates above 80% at 2× MIC/kg. Conclusions: Mn(II) and Co(II) significantly modulated the production of antifungal metabolites in Aspergillus sp. Fonsecinone B emerged as a promising candidate for antifungal therapy due to its potent activity and low toxicity. These findings support further investigation into the therapeutic potential of metal-induced fungal metabolites for combating drug-resistant Candida infections. Full article

Plants are continuously exposed to environmental challenges, including pollutants, pesticides, and heavy metals, collectively termed xenobiotics. These substances induce oxidative stress by generating reactive oxygen species (ROS), which can damage cellular components such as lipids, proteins, and nucleic acids. To counteract this, plants have evolved complex metabolic pathways to detoxify and process these harmful compounds. Oxidative stress in plants primarily arises from the overproduction of hydrogen peroxide (H₂O₂), superoxide anions (O₂^•−), singlet oxygen (¹O₂), and hydroxyl radicals (^•OH), by-products of metabolic activities such as photosynthesis and respiration. The presence of xenobiotics leads to a notable increase in ROS, which can result in cellular damage and metabolic disruption. To combat this, plants have developed a strong antioxidant defense mechanism that includes enzymatic antioxidants that work together to eliminate ROS, thereby reducing their harmful effects. In addition to enzymatic defenses, plants also synthesize various non-enzymatic antioxidants, including flavonoids, phenolic acids, and vitamins. These compounds effectively neutralize ROS and help regenerate other antioxidants, offering extensive protection against oxidative stress. The metabolism of xenobiotic substances in plants occurs in three stages: the first involves modification, which refers to the chemical alteration of xenobiotics to make them less harmful. The second involves conjugation, where the modified xenobiotics are combined with other substances to increase their solubility, facilitating their elimination from the plant. The third stage involves compartmentalization, which is the storage or isolation of conjugated xenobiotics in specific parts of the plant, helping to prevent damage to vital cellular functions. Secondary metabolites found in plants, such as alkaloids, terpenoids, and flavonoids, play a vital role in detoxification and the defense against oxidative stress. Gaining a deeper understanding of the oxidative mechanisms and the pathways of xenobiotic metabolism in plants is essential, as this knowledge can lead to the formulation of plant-derived strategies aimed at alleviating the effects of environmental pollution and enhancing human health by improving detoxification and antioxidant capabilities, as discussed in this review. Full article

Panicum maximum is planted extensively in tropical and subtropical areas, due to its high-quality forage and high biomass yield. This study aims to assess the varied metabolic dynamics of P. maximum subject to different pollution-related wastewater levels, thus providing information for sustainable agriculture and soil restoration. We analyzed the primary and secondary metabolites in P. maximum subject to two different types of polluted wastewater (WW), compared to a control group. The alterations observed in the metabolite profiles were affected by several factors, including nutrient imbalances and oxidative stress induced by heavy metal accumulation. Initially, the increased nutrient availability stemming from wastewater treatment promoted plant growth; however, this positive effect was later diminished by the adverse impacts of heavy metals, which generated oxidative stress, resulting in metabolic disturbances and a decrease in the plant biomass. Importantly, the substantial increase in antioxidant enzymes, related to primary (e.g., sugars) and secondary metabolites (e.g., phenolics and flavonoids), underscores plants’ adaptive strategies to cope with stress. The increased biosynthesis of flavonoids and phenolic compounds is a protective mechanism against oxidative stress, which also improves the antimicrobial activity, following the activation of key biosynthetic pathways involved in their synthesis. These complex interactions among diverse metabolites suggest that plants exposed to polluted wastewater use various biochemical strategies to increase both their survival and defenses against pathogens. Collectively, these findings emphasize the significance of understanding how wastewater management practices can affect plant health, metabolic responses, and the broader implications for food safety and ecosystem stability. Full article

Oxidative stress, driven by reactive oxygen, nitrogen, and sulphur species (ROS, RNS, RSS), poses a significant threat to cellular integrity and human health. Generated during mitochondrial respiration, inflammation, UV exposure and pollution, these species damage cells and contribute to pathologies like cardiovascular issues, neurodegeneration, cancer, and metabolic syndromes. Lifestyle factors exert a substantial influence on oxidative stress levels, with mitochondria emerging as pivotal players in ROS generation and cellular equilibrium. Phytochemicals, abundant in plants, such as carotenoids, ascorbic acid, tocopherols and polyphenols, offer diverse antioxidant mechanisms. They scavenge free radicals, chelate metal ions, and modulate cellular signalling pathways to mitigate oxidative damage. Furthermore, plants thriving in high-altitude regions are adapted to extreme conditions, and synthesize secondary metabolites, like flavonoids and phenolic compounds in bulk quantities, which act to form a robust antioxidant defence against oxidative stress, including UV radiation and temperature fluctuations. These plants are promising sources for drug development, offering innovative strategies by which to manage oxidative stress-related ailments and enhance human health. Understanding and harnessing the antioxidant potential of phytochemicals from high-altitude plants represent crucial steps in combating oxidative stress-induced disorders and promoting overall wellbeing. This study offers a comprehensive summary of the production and physio-pathological aspects of lifestyle-induced oxidative stress disorders and explores the potential of phytochemicals as promising antioxidants. Additionally, it presents an appraisal of high-altitude medicinal plants as significant sources of antioxidants, highlighting their potential for drug development and the creation of innovative antioxidant therapeutic approaches. Full article

Essential transition metals have key roles in oxygen transport, neurotransmitter synthesis, nucleic acid repair, cellular structure maintenance and stability, oxidative phosphorylation, and metabolism. The balance between metal deficiency and excess is typically ensured by several extracellular and intracellular mechanisms involved in uptake, distribution, and excretion. However, provoked by either intrinsic or extrinsic factors, excess iron, zinc, copper, or manganese can lead to cellular damage upon chronic or acute exposure, frequently attributed to oxidative stress. Intracellularly, mitochondria are the organelles that require the tightest control concerning reactive oxygen species production, which inevitably leaves them to be one of the most vulnerable targets of metal toxicity. Current therapies to counteract metal overload are focused on chelators, which often cause secondary effects decreasing patients’ quality of life. New therapeutic options based on synthetic or natural antioxidants have proven positive effects against metal intoxication. In this review, we briefly address the cellular metabolism of transition metals, consequences of their overload, and current therapies, followed by their potential role in inducing oxidative stress and remedies thereof. Full article

Recently, pollution caused by the heavy metal Cd has seriously affected the environment and agricultural crops. While Sinapis alba is known for its edible and medicinal value, its tolerance to Cd and molecular response mechanism remain unknown. This study aimed to analyze the tolerance of S. alba to Cd and investigate its molecular response mechanism through transcriptomic and physiological indicators. To achieve this, S. alba seedlings were treated with different concentrations of CdCl₂ (0.25 mmol/L, 0.5 mmol/L, and 1.0 mmol/L) for three days. Based on seedling performance, S. alba exhibited some tolerance to a low concentration of Cd stress (0.25 mmol/L CdCl₂) and a strong Cd accumulation ability in its roots. The activities and contents of several antioxidant enzymes generally exhibited an increase under the treatment of 0.25 mmol/L CdCl₂ but decreased under the treatment of higher CdCl₂ concentrations. In particular, the proline (Pro) content was extremely elevated under the 0.25 and 0.5 mmol/L CdCl₂ treatments but sharply declined under the 1.0 mmol/L CdCl₂ treatment, suggesting that Pro is involved in the tolerance of S. alba to low concentration of Cd stress. In addition, RNA sequencing was utilized to analyze the gene expression profiles of S. alba exposed to Cd (under the treatment of 0.25 mmol/L CdCl₂). The results indicate that roots were more susceptible to disturbance from Cd stress, as evidenced by the detection of 542 differentially expressed genes (DEGs) in roots compared to only 37 DEGs in leaves. GO and KEGG analyses found that the DEGs induced by Cd stress were primarily enriched in metabolic pathways, plant hormone signal transduction, and the biosynthesis of secondary metabolites. The key pathway hub genes were mainly associated with intracellular ion transport and cell wall synthesis. These findings suggest that S. alba is tolerant to a degree of Cd stress, but is also susceptible to the toxic effects of Cd. Furthermore, these results provide a theoretical basis for understanding Cd tolerance in S. alba. Full article

Heavy metals (HMs) contamination is one of the main abiotic factors affecting crop productivity and also threatens human health via consuming metal-contaminated crops as a food source. Over the past few years, HMs have drawn a lot of attention due to their increased use for commercial purposes and their harmful effects on plants and other life forms, thus threatening human survival. However, several methods have been adopted in recent years to combat the harsh effects of HMs. After phytohormones, the use of mineral nutrients such as selenium (Se) in the prevention of HM stress has been explored by researchers more recently. Selenium is an important micronutrient widely known for its antioxidant properties in plants and animals. Exogenous Se inhibits metal uptake and translocation and improves the antioxidant system, thus imparting resistance to HM toxicity in plants. Moreover, Se also regulates the production of various osmolytes in cells, which helps develop cell osmolarity. Selenium also produces different secondary metabolites in plants’ defense mechanisms against different stresses. The uptake of mineral nutrients is a vital process for plant growth and development, which is also positively correlated with Se under metalloid toxicity. However, to understand the exact mechanism of Se in HM tolerance, different metabolic processes stimulated by Se and their pathways need to be explored. Hence, this review focuses on the role of Se on nutritional status, antioxidant metabolism, interaction with phytohormones and its role in the regulation of various genes involved in Se-induced HM tolerance. Thus, this study will help researchers in the future for the improvement of HM tolerance via Se application in plants. Full article

The current state of heavy metal (HM) environmental pollution problems was considered in the review: the effects of HMs on the vital activity of plants and the functioning of their antioxidant system, including phenolic antioxidants. The latter performs an important function in the distribution and binding of metals, as well as HM detoxification in the plant organism. Much attention was focused on cadmium (Cd) ions as one of the most toxic elements for plants. The data on the accumulation of HMs, including Cd in the soil, the entry into plants, and the effect on their various physiological and biochemical processes (photosynthesis, respiration, transpiration, and water regime) were analyzed. Some aspects of HMs, including Cd, inactivation in plant tissues, and cell compartments, are considered, as well as the functioning of various metabolic pathways at the stage of the stress reaction of plant cells under the action of pollutants. The data on the effect of HMs on the antioxidant system of plants, the accumulation of low molecular weight phenolic bioantioxidants, and their role as ligand inactivators were summarized. The issues of polyphenol biosynthesis regulation under cadmium stress were considered. Understanding the physiological and biochemical role of low molecular antioxidants of phenolic nature under metal-induced stress is important in assessing the effect/aftereffect of Cd on various plant objects—the producers of these secondary metabolites are widely used for the health saving of the world’s population. This review reflects the latest achievements in the field of studying the influence of HMs, including Cd, on various physiological and biochemical processes of the plant organism and enriches our knowledge about the multifunctional role of polyphenols, as one of the most common secondary metabolites, in the formation of plant resistance and adaptation. Full article

Microplastics and nanoplastics (MPs/NPs) are posing emerging potential threats to global ecosystems and human health. Recently, the individual effects of MPs/NPs and combined effects of MPs/NPs-coexisting pollutants on soil–terrestrial plant systems have attracted increasing attention. Based on the latest research progress, this review firstly summarized the sources of MPs/NPs and the interaction between MPs/NPs and coexisting pollutants in soil environment, and then systematically induced their multilevel impacts on soil properties and terrestrial plants. Soil and agroecosystem are major long-term sinks of primary and secondary MPs/NPs, with extensive sources. MPs/NPs exhibit universal adsorption capacities and can further serve as the vectors for varied heavy metal, organic and biological contaminants. Generally, MPs/NPs and the combination with coexisting contaminants may affect soil physical, chemical and microbiological properties, soil structure and functions, while the specific impacts and degree depend on MP/NP characteristics including polymer type, size, shape, concentration and degradability. Increasing evidence confirmed the uptake and translocation of MPs/NPs in terrestrial plants and proved their influence on growth performance, metabolism and physiological toxicity, as well as cytotoxicity and genotoxicity. The specific effects vary as a function of MP/NPs properties, plant species and environmental conditions. The joint effects of MPs/NPs and coexisting pollutants are complex, and synergistic, antagonism and neutralization effects have been reported at different circumstances. Further comprehensive and in-depth studies are urgently needed to fulfill the current knowledge gaps, especially the deficiency in the inherent mechanisms. Full article

Medicinal plants (MPs) are important resources widely used in the treatment and prevention of diseases and have attracted much attention owing to their significant antiviral, anti-inflammatory, antioxidant and other activities. However, soil degradation, caused by continuous cropping, excessive chemical fertilizers and pesticide residues and heavy metal contamination, seriously restricts the growth and quality formation of MPs. Microorganisms, as the major biota in soil, play a critical role in the restoration of the land ecosystem. Rhizosphere microecology directly or indirectly affects the growth and development, metabolic regulation and active ingredient accumulation of MPs. Microbial resources, with the advantages of economic efficiency, harmless to environment and non-toxic to organisms, have been recommended as a promising alternative to conventional fertilizers and pesticides. The introduction of beneficial microbes promotes the adaptability of MPs to adversity stress by enhancing soil fertility, inhibiting pathogens and inducing systemic resistance. On the other hand, it can improve the medicinal quality by removing soil pollutants, reducing the absorption and accumulation of harmful substances and regulating the synthesis of secondary metabolites. The ecological and economic benefits of the soil microbiome in agricultural practices are increasingly recognized, but the current understanding of the interaction between soil conditions, root exudates and microbial communities and the mechanism of rhizosphere microecology affecting the secondary metabolism of MPs is still quite limited. More research is needed to investigate the effects of the microbiome on the growth and quality of different medicinal species. Therefore, the present review summarizes the main soil issues in medicinal plant cultivation, the functions of microbes in soil remediation and plant growth promotion and the potential mechanism to further guide the use of microbial resources to promote the ecological cultivation and sustainable development of MPs. Full article

Mitochondria are the main sites for oxidative phosphorylation and synthesis of adenosine triphosphate in cells, and are known as cellular power factories. The phrase “secondary mitochondrial diseases” essentially refers to any abnormal mitochondrial function other than primary mitochondrial diseases, i.e., the process caused by the genes encoding the electron transport chain (ETC) proteins directly or impacting the production of the machinery needed for ETC. Mitochondrial diseases can cause adenosine triphosphate (ATP) synthesis disorder, an increase in oxygen free radicals, and intracellular redox imbalance. It can also induce apoptosis and, eventually, multi-system damage, which leads to neurodegenerative disease. The catechin compounds rich in tea have attracted much attention due to their effective antioxidant activity. Catechins, especially acetylated catechins such as epicatechin gallate (ECG) and epigallocatechin gallate (EGCG), are able to protect mitochondria from reactive oxygen species. This review focuses on the role of catechins in regulating cell homeostasis, in which catechins act as a free radical scavenger and metal ion chelator, their protective mechanism on mitochondria, and the protective effect of catechins on mitochondrial deoxyribonucleic acid (DNA). This review highlights catechins and their effects on mitochondrial functional metabolic networks: regulating mitochondrial function and biogenesis, improving insulin resistance, regulating intracellular calcium homeostasis, and regulating epigenetic processes. Finally, the indirect beneficial effects of catechins on mitochondrial diseases are also illustrated by the warburg and the apoptosis effect. Some possible mechanisms are shown graphically. In addition, the bioavailability of catechins and peracetylated-catechins, free radical scavenging activity, mitochondrial activation ability of the high-molecular-weight polyphenol, and the mitochondrial activation factor were also discussed. Full article

Industrial hemp (Cannabis sativa L.), an annual herbaceous cash crop, is widely used for the remediation of heavy metal-contaminated soils due to its short growth cycle, high tolerance, high biomass, and lack of susceptibility to transfer heavy metals into the human food chain. In this study, a significant increase in proanthocyanidins was found in Yunnan hemp no. 1 after cadmium stress. Proanthocyanidins are presumed to be a key secondary metabolite for cadmium stress mitigation. Therefore, to investigate the effect of proanthocyanidins on industrial hemp under cadmium stress, four experimental treatments were set up: normal environment, cadmium stress, proanthocyanidin treatment, and cadmium stress after pretreatment with proanthocyanidins. The phenotypes from the different treatments were compared. The experimental results showed that pretreatment with proanthocyanidins significantly alleviated cadmium toxicity in industrial hemp. The transcriptome and metabolome of industrial hemp were evaluated in the different treatments. Proanthocyanidin treatment and cadmium stress in industrial hemp mainly affected gene expression in metabolic pathways associated with glutathione metabolism, phenylpropanoids, and photosynthesis, which in turn altered the metabolite content in metabolic pathways of phenylalanine, vitamin metabolism, and carotenoid synthesis. The combined transcriptomic and metabolomic analysis revealed that proanthocyanidins mitigated cadmium toxicity by enhancing photosynthesis, secondary metabolite synthesis, and antioxidant synthesis. In addition, exogenous proanthocyanidins and cadmium ions acted simultaneously on EDS1 to induce the production of large amounts of salicylic acid in the plant. Finally, overexpression of CsANR and CsLAR, key genes for proanthocyanidins synthesis in industrial hemp, was established in Arabidopsis plants. The corresponding plants were subjected to cadmium stress, and the results showed that CsLAR transgenic plants were more tolerant to cadmium than the CsANR transgenic and wild-type Arabidopsis plants. The results showed that salicylic acid and jasmonic acid were increased in Arabidopsis overexpressing CsLAR compared to AT wild-type Arabidopsis, and levels of secondary metabolites were significantly higher in Arabidopsis overexpressing CsLAR than in AT wild-type Arabidopsis. These results revealed how proanthocyanidins alleviated cadmium stress and laid the foundation for breeding industrial hemp varieties with higher levels of proanthocyanidins and greater tolerance. Full article

Bacillus velezensis gram-positive bacterium, is frequently isolated from diverse niches mainly soil, water, plant roots, and fermented foods. B. velezensis is ubiquitous, non-pathogenic and endospore forming. Being frequently isolated from diverse plant holobionts it is considered host adapted microorganism and recognized of high economic importance given its ability to promote plant growth under diverse biotic and abiotic stress conditions. Additionally, the species suppress many plant diseases, including bacterial, oomycete, and fungal diseases. It is also able after plant host root colonization to induce unique physiological situation of host plant called primed state. Primed host plants are able to respond more rapidly and/or effectively to biotic or abiotic stress. Moreover, B. velezenis have the ability to resist diverse environmental stresses and help host plants to cope with, including metal and xenobiotic stresses. Within species B. velezensis strains have unique abilities allowing them to adopt different life styles. Strain level abilities knowledge is warranted and could be inferred using the ever-expanding new genomes list available in genomes databases. Pangenome analysis and subsequent identification of core, accessory and unique genomes is actually of paramount importance to decipher species full metabolic capacities and fitness across diverse environmental conditions shaping its life style. Despite the crucial importance of the pan genome, its assessment among large number of strains remains sparse and systematic studies still needed. Extensive knowledge of the pan genome is needed to translate genome sequencing efforts into developing more efficient biocontrol agents and bio-fertilizers. In this study, a genome survey of B. velezensis allowed us to (a) highlight B. velezensis species boundaries and show that Bacillus suffers taxonomic imprecision that blurs the debate over species pangenome; (b) identify drivers of their successful acquisition of specific life styles and colonization of new niches; (c) describe strategies they use to promote plant growth and development; (d) reveal the unlocked strain specific orphan secondary metabolite gene clusters (biosynthetic clusters with corresponding metabolites unknown) that product identification is still awaiting to amend our knowledge of their putative role in suppression of pathogens and plant growth promotion, and (e) to describe a dynamic pangenome with a secondary metabolite rich accessory genome. Full article