Background: Plants face a wide range of environmental stresses that disrupt growth and productivity. To survive and adapt, they undergo complex metabolic reprogramming by redirecting carbon and nitrogen fluxes toward the biosynthesis of protective secondary metabolites such as phenylpropanoids, flavonoids, and lignin. Recent research has revealed that these stress-induced metabolic processes are tightly regulated by epigenetic mechanisms, including DNA methylation, histone modifications, chromatin remodeling, and non-coding RNAs. Methods: This review synthesizes current findings from studies on both model and crop plants, examining the roles of key epigenetic regulators in controlling secondary metabolism under stress. Special focus is placed on dynamic changes in DNA methylation, histone acetylation, and the action of small RNAs such as siRNAs and miRNAs in transcriptional and post-transcriptional regulation. Results: Evidence indicates that stress triggers rapid and reversible epigenetic modifications that modulate gene expression linked to secondary metabolic pathways. These modifications not only facilitate immediate metabolic responses but can also contribute to stress memory. In some cases, this memory is retained and transmitted to the next generation, influencing progeny stress responses. However, critical knowledge gaps remain, particularly concerning the temporal dynamics, tissue specificity, and long-term stability of these epigenetic marks in crops. Conclusions: Understanding how epigenetic regulation governs secondary metabolite production offers promising avenues to enhance crop resilience and productivity in the context of climate change. Future research should prioritize dissecting the stability and heritability of these modifications to support the development of epigenetically informed breeding strategies.

In traditional medicine, plants are widely utilized as sources of bioactive compounds for treating various diseases. This study aimed to evaluate the secondary metabolite composition, antioxidant properties, and antimicrobial effects of 38 medicinal plants commonly used in Bosnia and Herzegovina. Plants were collected from natural habitats, and dried plant material from different organs, selected based on their traditional medicinal use, was used for the extraction of bioactive compounds with 80% ethanol. The extracts were analysed for phenolic, flavonoid, and tannin content, as well as antioxidant capacity (using DPPH and FRAP assays) and antimicrobial activity. The antimicrobial activity of all 38 plants was initially screened using the disc diffusion method. For plants showing significant antimicrobial activity (inhibition zones > 20 mm), the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. All analysed plants exhibited high phenolic content, with Melissa officinalis leaf extract, Filipendula vulgaris flower extract, and Rubus plicatus leaf extract containing over 300 mg GAE/g DW. According to the DPPH assay, high antioxidant capacity was observed in extracts from the leaves of Fragaria vesca, Prunus armeniaca, Rubus plicatus, and R. ideus, as well as in Rosa canina fruit and Filipendula vulgaris flower extracts, with values reaching 702.39 mg TE/g DW. Among the 38 tested plants, 16 exhibited high antimicrobial activity with inhibition zones greater than 20 mm. To ensure both the efficacy and safety of these plants, further studies on their toxicity, particularly dose-dependent toxicity, are necessary.

Dimeric forms of flavonoids, known as biflavonoids, are much less studied compared to monomeric forms. It is estimated that nearly 600 different natural biflavonoids have been described to date, containing various subtypes that can be subdivided according to the position of their combinations and the nature of the subunits. The group in which two monomers are linked by a 3′-8″-C atom includes the first isolated biflavonoid ginkgetin, derivatives of amentoflavone, and several other compounds. 3′-8″-biflavones recently attracted much attention as potential molecules with biological activity such as antiviral and antimicrobial activity and as effective molecules for the treatment of neurodegenerative and metabolic diseases and in cancer therapies. With the growing interest in them as pharmacologically active molecules, there is also increasing interest in finding new natural sources of 3′-8″-biflavones and optimizing methods for their extraction and identification. Herein, we have summarized the available data on the structural diversity, natural occurrence, role in plants, extraction, and identification of 3′-8″-biflavones.

Chickpea and lentils are one of the most important legumes not only as sources of food and nutrients but also for enrichment of soil as a nitrogen fixating crop. An early onset of higher temperatures and drought are affecting chickpea and lentil growth and flowering leading to reduction of yield. In search for a tolerant varieties presented study performed a large-scale screening of two legume varieties (chickpea and lentils) investigating phenotypical response to early onset of drought under heat stress. Under heat stress and two different irrigation conditions, 19 chickpea and 18 lentil accessions were examined. The evaluation focused on their growth, biomass production, and flowering rate in comparison to commercially available varieties. Six chickpea accessions showed tolerance to water stress while only two lentil accessions differed from the rest of tested accessions. Generally, lentils genotypes were less stressed by decreased water availability compared to chickpea. Large scale screening of legume accessions could be a valuable tool to identify new varieties that could show phenotypical traits more adaptable to climate related environmental stresses. To improve the reproductive efficiency in chickpeas and lentils under adverse conditions associated to climate change an extensive breeding effort should be focused on investigation of more tolerant genotypes and cultivation in crop systems.

The increase in soil salinity has a negative effect on the growth and yield of plants. Mitigating the negative effects of soil salinity is therefore a difficult task and different methods are being used to overcome the negative effects of salt stress on crop plants. One of the often-used approaches is seed priming that can increase plants’ vigor and resilience. In this paper, we tested the effects of hydropriming, proline priming, and salicylic acid priming on the mitigation of the negative effects of salt stress on two bell pepper varieties (Capsicum annuum L.): Herkules and Kurtovska kapija. Sweet bell pepper seeds were primed following desiccation to achieve the original water content, and subsequently cultivated in salt-supplemented medium. The positive effects on vigor (in the form of increased germination and seedling establishment) as well as on level of tolerance for salt stress were recorded for both cultivars. The positive effects varied between the priming treatments and pepper cultivar used. The results of germination, seedling performance, photosynthetic pigments, and osmolytes were measured for seedlings grown from unprimed and primed seeds with under 0, 25, and 50 mM of NaCl. Both cultivars demonstrated greater germination when primed with proline and salicylic acid, while the Herkules cultivar demonstrated a higher tolerance to salt when proline was used as the priming agent. Priming with salicylic acid and proline in the seed improved germination and seedling performance, which could be related to the increase in proline content in the seedlings.

Biflavonoids are dimeric forms of flavonoids that have recently gained importance as an effective new scaffold for drug discovery. In particular, 3′-8″-biflavones exhibit antiviral and antimicrobial activity and are promising molecules for the treatment of neurodegenerative and metabolic diseases as well as cancer therapies. In the present study, we directly compared 3′-8″-biflavones (amentoflavone, bilobetin, ginkgetin, isoginkgetin, and sciadopitysin) and their monomeric subunits (apigenin, genkwanin, and acacetin) and evaluated their radical scavenging activity (with DPPH), antifungal activity against mycotoxigenic fungi (Alternaria alternata, Aspergillus flavus, Aspergillus ochraceus, Fusarium graminearum, and Fusarium verticillioides), and inhibitory activity on enzymes (acetylcholinesterase, tyrosinase, α-amylase, and α-glucosidase). All the tested compounds showed weak radical scavenging activity, while antifungal activity strongly depended on the tested concentration and fungal species. Biflavonoids, especially ginkgetin and isoginkgetin, proved to be potent acetylcholinesterase inhibitors, whereas monomeric flavonoids showed higher tyrosinase inhibitory activity than the tested 3′-8″-biflavones. Amentoflavone proved to be a potent α-amylase and α-glucosidase inhibitor, and in general, 3′-8″-biflavones showed a stronger inhibitory potential on these enzymes than their monomeric subunits. Thus, we can conclude that 3′-8″-dimerization enhanced acetylcholinesterase, α-amylase, and α-glucosidase activities, but the activity also depends on the number of hydroxyl and methoxy groups in the structure of the compound.

Cadmium (Cd) is considered one of the most toxic heavy metals to living organisms, being very persistent in soil and non-biodegradable, thus posing a long-term hazard to plants and humans. In recent years, the application of different molecules at the seed level, known as chemical seed priming, has been studied as a method to improve stress tolerance in plants. In the present study, we tested the effect of hydro-priming and proline priming of lettuce (Lactuca sativa L.) seeds on germination, photosynthetic pigments, and metal metabolism under cadmium stress. Plants primed with proline showed better germination under cadmium stress (100% versus 84% for non-primed and hydro-primed seeds). Priming with 20 mM of proline increased the chlorophyll a and total chlorophyll contents by 40.8% and 18.6%, respectively, while these parameters decreased in other seedlings under Cd stress. Similarly, 20 mM of proline improved the uptake of Zn and Fe in roots under Cd stress. This indicates that 20 mM of proline treatments may be beneficial for maintaining a normal photosynthetic capacity and mineral uptake under Cd stress, but further metabolomics and transcriptomic data should reveal the exact mechanisms of action.

Epigenetic modifications play a vital role in the preservation of genome integrity and in the regulation of gene expression. DNA methylation, one of the key mechanisms of epigenetic control, impacts growth, development, stress response and adaptability of all organisms, including plants. The detection of DNA methylation marks is crucial for understanding the mechanisms underlying these processes and for developing strategies to improve productivity and stress resistance of crop plants. There are different methods for detecting plant DNA methylation, such as bisulfite sequencing, methylation-sensitive amplified polymorphism, genome-wide DNA methylation analysis, methylated DNA immunoprecipitation sequencing, reduced representation bisulfite sequencing, MS and immuno-based techniques. These profiling approaches vary in many aspects, including DNA input, resolution, genomic region coverage, and bioinformatics analysis. Selecting an appropriate methylation screening approach requires an understanding of all these techniques. This review provides an overview of DNA methylation profiling methods in crop plants, along with comparisons of the efficacy of these techniques between model and crop plants. The strengths and limitations of each methodological approach are outlined, and the importance of considering both technical and biological factors are highlighted. Additionally, methods for modulating DNA methylation in model and crop species are presented. Overall, this review will assist scientists in making informed decisions when selecting an appropriate DNA methylation profiling method.

To improve our understanding of the molecular mechanisms underlaying seed priming, RNA transcriptome analysis was performed using primed and non-primed seeds of Silene sendtneri. Seed priming was performed by submergence in 1% silicic acid for 24h at 4°C, followed by rinsing with sterilised water and desiccation to original moisture content. Silene sendtneri is a species with no sequenced genome and annotation of de novo assembly of transcriptome was done against several species. Gene ontology (GO) analysis indicated that genes related to heavy metal transporters and heat shock proteins are differentially expressed after priming with silicic acid. Within these gene categories, genes such as heavy metal-associated isoprenylated plant protein 26-like (log2fold -8.79) were downregulated, while others such as heavy metal ATPase 5 (log2fold 6.46), heat shock factor protein HSF30-like isoform X1 (log2fold 5.98) were upregulated.

The global increase in temperature and associated meteorological disruptions, such as the earlier onset of high temperatures and disruptions in precipitation, are becoming severely limiting factors in crop cultivation. Chickpea, as a cool season crop, is under the direct influence of heat and drought stress that is not only affecting this crop in its podding stage but, with current climate trends, the drought and heat are now also affecting earlier stages, such as flowering. The deteriorating effects of heat and droughts include reduced flowering, abortion of flowers and absence of podding; thus, this is severely affecting crop yield. Further research has been conducted to identify the genes correlated to higher stress tolerance and to utilize them in developing more tolerant varieties. Different alleviation approaches have been also tested and it has been determined that some positive effects can be seen in supplementation with Zn through melioration of water relations, seed priming and some transgenic and genome editing approaches. Breeding strategies for future chickpea varieties have been focused on the identification of varieties with more tolerant traits for an improved yield under stressed conditions. In this review, we have reviewed recent strategies and biotechnological approaches that have been used with chickpea crops to address the two major abiotic stresses (heat and drought) linked to future climate change.