Vulgaris Plants Research Articles

Comparative Analysis of Foliar Diseases of Some Native and Non-Native Tree Species in Belarus and Siberia

Urban green spaces are known to be subjected to additional anthropogenic stress. Using native plants in monoculture, i.e., planting trees of the same species, may favour disease outbreaks and plant death. Non-native plants to be used in large cities for creating sustainable plantations are being searched for worldwide. Meanwhile, it is necessary to control plant pathogens in the variable conditions of the region and natural habitat. In Siberian cities, non-native European trees are used, and non-native Siberian plants are introduced in Belarus. This article reports long-term observations of foliar fungal pathogens attacking 21 woody plants (19 European, 2 Siberian) in Siberian and Belarusian cities. In both regions, 48 leaf fungal pathogens were detected, with powdery mildew fungi predominating in Belarus and leaf spotting fungi prevailing in Siberia. In both research regions, the greatest number of fungal species was found on Syringa vulgaris L. In Siberia, many pathogens were found on the non-native European plant Berberis vulgaris (9 species) and native plant Caragana arborescens Lam. (8 species). We have not detected the pathogens on European plants: Acer campestre L., Acer platanoides L., Euonymus europaeus L., Lonicera caprifolium L. in urban green areas in Siberia, while we have identified one to four foliar fungal pathogens on these plants in Belarus. To sum up: more pathogens were found on native plants in Siberia and Belarus; some leaf pathogen species (Sawadaea tulasnei (Fuckel) Homma, Erysiphe alphitoides (Griffon & Maubl.) U. Braun & S. Takam., Cladosporium syringae (Oudem.) Montem., Erysiphe syringae Schwein., Erysiphe palczewskii (Jacz.) U. Braun & S. Takam.) followed their host plants (Acer tataricum L., Syringa vulgaris L., Caragana arborescens Lam.) when introduced into new areas; and some local pathogens were also observed to spread to the non-native plants of closely related species.

Response of Phaseolus vulgaris plants to foliar spray and soil drenching by silver nanoparticles (Ag+NPS).

Response of Phaseolus vulgaris plants to foliar spray and soil drenching by silver nanoparticles (Ag+NPS).

Genome-wide analysis of pathogenesis-related protein-1 (PR-1) genes from Qingke (Hordeum vulgare L. var. nudum) reveals their roles in stress responses

Proteins that are pathogenesis-related 1 (PR-1) can accumulate to high levels when plants employ defenses, being major participants in processes critical for stress responses as well as development of many species. Yet we still lack information concerning PR-1 family members in Qingke plants (Hordeum vulgare L. var. nudum). In this work, we distinguished 20 PR-1s from the Qingke genome whose encoded proteins often featured at the N-terminus a signal peptide; all 20 PR-1s were predicted to localize either periplasmically or extracellularly. The CAP domain was confirmed as being highly conserved in all these PR-1s. Phylogeny-based inference revealed that PR-1 proteins clustered into four major clades, with the majority of Qingke PR-1s distributed in clade I (17 out 20), and the other 3 distributed in clade II. Gene structure analysis showed that 16 PR-1s did not contain any introns, whereas the other four had 1–4 introns. We identified a variety of motifs that are cis-acting in the promoter regions of PR-1s; these included those potentially involved in Qingke's light response, hormonal and stress responses, circadian control and regulation of development and growth, in addition to sites where transcription factors bind to. Expression analysis uncovered several members of PR-1 genes that were strongly and rapidly induced by powdery mildew infection, phytohormones, and cold stimulus. Altogether, our study's findings enhance what is known about genetic features of PR-1 family members in H. vulgare plants, especially Qingke, and could thereby facilitate further exploration aiming to elucidate the functioning of these proteins.

AI-assisted antifungal discovery of Aspergillus parasiticus and Aspergillus flavus: investigating the potential of Asphodelus aestivus, Beta vulgaris, and Morus alba plant leaf extracts

AI-assisted antifungal discovery of Aspergillus parasiticus and Aspergillus flavus: investigating the potential of Asphodelus aestivus, Beta vulgaris, and Morus alba plant leaf extracts

The efficacy of banana compost as biofertilizer on barley (Hordeum vulgare) plants grown on soil polluted with cadmium.

The efficacy of banana compost as biofertilizer on barley (Hordeum vulgare) plants grown on soil polluted with cadmium.

Measuring residual transpiration in plants: a comparative analysis of different methods.

Residual transpiration (RT) is defined as a loss of water through the leaf cuticle while stomata are closed. Reduced RT might be a potentially valuable trait for improving plant performance under water deficit conditions imposed by either drought or salinity. Due to the presence of stomata on the leaf surface, it is technically challenging to measure RT. RT has been estimated by the water loss through either astomatous leaf surface or isolated astomatous cuticular layers. This approach is not suitable for all species (e.g. not applicable to grasses) and is difficult and too time consuming for large-scale screening in breeding programs. Several alternative methods may be used to quantify the extent of RT; each of them comes with its own advantages and limitations. In this study, we have undertaken a comparative assessment of eight various methods of assessing RT, using barley (Hordeum vulgare ) plants as a model species. RT measured by water retention curves and a portable gas exchange (infrared gas analyser; IRGA) system had low resolution and were not able to differentiate between RT rates from young and old leaves. Methods based on quantification of the water loss at several time-points were found to be the easiest and least time-consuming compared to others. Of these, the 'three time-points water loss' method is deemed as the most suitable for the high throughput screening of plant germplasm for RT traits.

Preliminary results of in-vitro laboratory propagation of barberry (Berberis L.)

The genus Berberis vulgaris (Berberis L.) is currently found in tropical, subtropical, temperate, and cold climate zones. There is little doubt that Southeast Asia is where the majority of Berberis vulgaris' interspecies biodiversity is found. Additionally, species are widely distributed, mostly in hilly areas, and, in terms of moisture requirements, they are mesophytic and xeromesophytic plants. In this article, experiments on in-vitro propagation of Berberis vulgaris (Berberis L.) seedlings were carried out in laboratory conditions. During the experiments, the time of sterilization of the explants obtained from the Berberis vulgaris plant was determined. Different concentrations of hormones and auxins were used in several nutrient mediums for growing in artificial nutrient medium. The results depicted that the highest rate was observed in the variant, where 2ml.BAP+0.5NAA+30g sucrose+7g accounted for 87% of plant rooting rate. It was observed that the rooting rate was slightly higher in the control variant of WPM-Woody plant medium-nutrient medium than the control variant of the MS nutrient medium, which was 17%.

Highly active iron (II) oxide-zinc oxide nanocomposite synthesized Thymus vulgaris plant as bioreduction catalyst: Characterization, hydrogen evolution and photocatalytic degradation

This study aimed to synthesize an iron (II) oxide-zinc oxide (Fe2O3/ZnO) nanocomposite using eco-friendly methods and to evaluate its performance as a catalyst against textile dyes and hydrogen generation. To these means, Fe2O3/ZnO was synthesized from the Thymus vulgaris plant by biogenic methods. The resulting nanocomposite was characterized by Fourier Transmission Infrared Spectroscopy, Transmission Electron Microscopy (TEM), UV–vis spectrometry, and X-Ray diffraction patterns (XRD). According to the obtained TEM characterization results, it was observed that the nanocomposite had an average size of 3.78 nm. According to the XRD results, the nanocomposite's average crystal size was 3.884 nm. In addition, the hydrogen release was investigated by NaBH4 hydrolysis. The turnover frequency, activation energy (Ea), entropy (ΔS), and enthalpy (ΔH) values obtained from hydrogen production studies are 1942.23 h−1 and 15.68 kJ/mol, −127.29 J/mol K, and 13.14 kJ/mol, respectively. In the reusability tests, it was observed that the nanocomposite was 78% effective. The photocatalytic studies using solar energy revealed that the nanocomposite was 79% effective for methylene blue (MB) dye removal. This work demonstrated the potential of transition metals for energy production. It showed that the developed nanocomposite could be a viable solution and, with further development, can be an efficient catalyst for alternative energy production (energy generation) and textile industry wastewater treatment.

Plant Growth Promoting Rhizobacteria and Silica Nanoparticles Stimulate Sugar Beet Resilience to Irrigation with Saline Water in Salt-Affected Soils.

Combined stressors (high soil salinity and saline water irrigation) severely reduce plant growth and sugar beet yield. Seed inoculation with plant growth-promoting rhizobacteria (PGPR) and/or foliar spraying with silica nanoparticles (Si-NP) is deemed one of the most promising new strategies that have the potential to inhibit abiotic stress. Herein, sugar beet (Beta vulgaris) plants were treated with two PGPR (Pseudomonas koreensis MG209738 and Bacillus coagulans NCAIM B.01123) and/or Si-NP, during two successive seasons 2019/2020 and 2020/2021 to examine the vital role of PGPR, Si-NP, and their combination in improving growth characteristics, and production in sugar beet plants exposed to two watering treatments (fresh water and saline water) in salt-affected soil. The results revealed that combined stressors (high soil salinity and saline water irrigation) increased ion imbalance (K+/Na+ ratio; from 1.54 ± 0.11 to 1.00 ± 0.15) and declined the relative water content (RWC; from 86.76 ± 4.70 to 74.30 ± 3.20%), relative membrane stability index (RMSI), stomatal conductance (gs), and chlorophyll content, which negatively affected on the crop productivity. Nevertheless, the application of combined PGPR and Si-NP decreased oxidative stress indicators (hydrogen peroxide and lipid peroxidation) and sodium ions while increasing activities of superoxide dismutase (SOD; up to 1.9-folds), catalase (CAT; up to 1.4-folds), and peroxidase (POX; up to 2.5-folds) enzymes, and potassium ions resulting in physiological processes, root yield, and sugar yield compared to non-treated controls under combined stressors (high soil salinity and saline water irrigation). It is worth mentioning that the singular application of PGPR improved root length, diameter, and yield greater than Si-NP alone and it was comparable to the combined treatment (PGPR+Si-NP). It was concluded that the combined application of PGPR and Si-NP has valuable impacts on the growth and yield of sugar beet growing under combined stressors of high soil salinity and saline water irrigation.

Simultaneous Action of Silymarin and Dopamine Enhances Defense Mechanisms Related to Antioxidants, Polyamine Metabolic Enzymes, and Tolerance to Cadmium Stress in Phaseolus vulgaris.

Silymarin (Sm) and dopamine (DA) act synergistically as potential antioxidants, mediating many physiological and biochemical processes. As a first report, we investigated the synergistic effect of Sm and DA in mitigating cadmium stress in Phaseolus vulgaris plants. Three experiments were conducted simultaneously using 40 cm diameter pots to elucidate how Sm and DA affect cadmium tolerance traits at morphological, physiological, and biochemical levels. Cadmium stress triggered a marked reduction in growth, productivity, and physio-biochemical characteristics of common bean plants compared to unstressed plants. Seed priming (SP) and foliar spraying (FS) with silymarin (Sm) or dopamine (DA) ((DA (SP) + Sm (FS) and Sm (SP) + DA (FS)) ameliorated the damaging effects of cadmium stress. Sm seed priming + DA foliar spraying (Sm (SP) + DA (FS)) was more efficient. The treated stressed common bean plants showed greater tolerance to cadmium stress by diminishing oxidative stress biomarkers (i.e., O2•-, H2O2, and MDA) levels through enhanced enzymatic (SOD, CAT, POD, APX) and non-enzymatic (ascorbic acid, glutathione, α-tocopherol, choline, phenolics, flavonoids) antioxidant activities and osmoprotectants (proline, glycine betaine, and soluble sugars) contents, as well as through improved photosynthetic efficiency (total chlorophyll and carotenoids contents, photochemical activity, and efficiencies of carboxylation (iCE) and PSII (Fv/Fm)), polyamines (Put, Spd, and Spm), and polyamine metabolic enzymes (ADC and ODC) accumulation. These findings signify that Sm and DA have remarkable anti-stress effects, which can help regulate plant self-defense systems, reflecting satisfactory plant growth and productivity. Thus, realizing the synergistic effect of Sm and DA in cadmium tolerance confers potential new capabilities for these compounds to function in sustainable agriculture.

Air pollution in Sarajevo, Bosnia and Herzegovina, assessed by plant comet assay.

Bosnia and Herzegovina (B&H) is among the European countries with the highest rate of air pollution-related death cases and the poorest air quality. The main causes are solid fuel consumption, traffic, and the poorly developed or implemented air pollution reduction policies. In addition, the city of Sarajevo, the capital of B&H, suffers temperature inversion episodes in autumn/winter months, which sustain air pollution. Human biomonitoring studies may be confounded by the lifestyle of subjects or possible metabolic alterations. Therefore, this study aimed to evaluate Ligustrum vulgare L. as a model for air pollution monitoring by measuring DNA damage at one rural and two urban sites. DNA damage was measured as tail intensity (TI) in L. vulgare leaves, considering seasonal, sampling period, leaf position and staging, and spatial (urban versus rural) variation. Effects of COVID-19 lockdown on TI were assessed by periodical monitoring at one of the selected sites, while in-house grown L. vulgare plants were used to test differences between outdoor and indoor air pollution effects for the same sampling period. Significantly higher TI was generally observed in leaves collected in Campus in December 2020 and 2021 compared with March (P < 0.0001). Outer and adult leaves showed higher TI values, except for the rural site where no differences for these categories were found. Leaves collected in the proximity of the intensive traffic showed significantly higher TI values (P < 0.001), regardless of the sampling period and the stage of growth. In regards to the COVID-19 lockdown, higher TI (P < 0.001) was registered in December 2020, after the lockdown period, than in periods before COVID-19 outbreak or immediately after the lockdown in 2020. This also reflects mild air pollution conditions in summer. TI values for the in-house grown leaves were significantly lower compared to those in situ. Results showed that L. vulgare may present a consistent model for the air pollution biomonitoring but further studies are needed to establish the best association between L. vulgare physiology, air quality data, and air pollution effects.

Genome-Wide Analysis and Characterization of the PIF Gene Family Under Salt and Drought Stress in Common Beans (Phaseolus vulgaris L.)

The purpose of this study was to identify and describe members of the phytochrome-interacting factors (PIFs) gene family including the basic helix loop helix (bHLH) binding site in Phaseolus vulgaris plants, as well as to investigate their responses to salt and drought stress. Various tools of in silico approaches were used to identify five Pvul-PIF gene families in the P. vulgaris genome. This gene family contained 324 to 726 amino acids and has molecular weights ranging from 35.11 kDa to 77.67 kDa. The theoretical isoelectric points range from 6.03 (Pvul-PIF-3.3) to 8.30 (Pvul-PIF-3.2). Pvul-PIF proteins were shown to be clustered in three main groups with Arabidopsis thaliana, Populus trichocarpa, Solanum lycopersicum, Zea mays, Arachis hypogaea L., Oryza sativa, Vitis vinifera, Glycine max, and Phaseolus vulgaris species as a result of the phylogenetic study. Segmental duplication was detected between Pvul-PIF-3.2, Pvul-PIF-3.3 and Pvul-PIF-3.1 genes, Pvul-PIF-4.1 and Pvul-PIF-4.2 genes and Pvul-PIF-3.3 and Pvul-PIF-3.1 genes. When the expression patterns of the Pvul-PIF genes were examined, it was observed that they had different levels of expression under salt and drought stress and that they may be involved in specific biological and molecular processes in response to different abiotic and biotic stresses. The results of this research, which were established for the first time in response to salt and drought stress in P. vulgaris of the PIF gene family, will be a valuable source of knowledge and additional information in the fields of plant biotechnology, agricultural biotechnology, and molecular biology.

GREEN SYNTHESIS AND CHARACTERIZATION OF ALCHEMILLA VULGARIS SILVER NANOPARTICLES

Among all the nanoparticles synthesized; silver nanoparticles have attained special place in the area of nano technology because of their antimicrobial, nontoxic, environmentally safe and biomedical applications. In general; their syntheses involves the use of hazardous chemicals or costly physical methods. However, the biological processes are making their ways in between and proving their advantages over them. The use of plants and their extracts is one of the most valuable methods which are gaining concerns due to their imperative biological benefits. Plants are not only beautiful but majestic because they are rich sources of various medicinally important substances. They explore the huge diversity which can be utilized towards rapid and single step protocol preparatory method for various nanoparticles keeping intact “the green principles” over the conventional ones and proving their dominance for medicinal importance. Here, in the presented work “one pot synthesis of silver nanoparticles” is described. Therefore; a simple, cost effective bio-reduction on the principle of “green synthesis” of silver nanoparticles using the Alchemilla vulgaris plant extract is reported. The beauty of the synthesis is: no involvement of any surfactant, catalyst or template. The aqueous silver ions are reduced to silver nanoparticles when exposed to plant extract. The bio-reduction and stabilization of so formed silver nanoparticles was monitored by UV-Vis spectrophotometry, FTIR spectroscopy, SEM, particle size and zeta potential.

Using different organic wastes to improve the quality of desert soils and barley (Hordeum vulgare) plant growth

The concept of the public in food safety, as well as environmental aspects, has newly improved to crops cultivated with organic fertilizers instead of chemical fertilizers. A study was conducted on various organic wastes for the improvement of desert soils and the growth of Hordeum vulgare plants. Desert soil sample, Hordeum vulgare plants, different organic wastes (Waste food and Animals waste), were used in a completely randomized design with three replications. Five treatments were used included T1=control (without composts), T2=25%, T3=50%, T4=75% and T5 100% with composts. Soil chemical properties were influenced by the use of waste compost amendments. There was a decrease in the soil pH from 8.7 to 7.0 at 50% waste food and mixed compost treatments. The EC and TDS were increased under composite treatments however, the treatments at 75% waste food compost gave high values for the CEC 38.75 cmol/kg. The exchangeable Ca, Mg, Na, K, N were increased in compost treatments. NO3 was increased from 1.29 mg/kg (in control) to 1.41 mg/kg in soil treated with 75% food waste compost. Among composts, the applications of food waste compost at 10% gave the highest plant height (18.1 cm), the number of plant leaves (6), and root biomass (6.77g dry weight). The use of various composts particularly food waste compost can be used in desert soils to improve crop growth and yield of Hordeum vulgare crop.

Plant growth promoting and antagonistic Enterobacter sp. EPR4 from common bean rhizosphere of garhwal himalayan inhibits a soil-borne pathogen Sclerotinia sclerotiorum

Plant growth stimulating and antagonistic properties of 7 bacterial isolates of beneficial Enterobacter spp. (EPR1- EPR7) screened from the rhizospheric soil of Phaseolus vulgaris plants growing in Garhwal Himalaya, Uttarakhand, India was studied against soil borne phytopathogen Sclerotinia sclerotiorum causes root rots in various crops. Among the isolates, EPR4 showed 64.8% reduction in colony growth of the fungal pathogen in dual culture. All seven isolates are capable of producing Indole Acetic Acid (IAA), but EPR4 also produced cyanogens, solubilized inorganic and organic phosphate, siderophore, ACC (1-aminocyclopropane-1-carboxylic acid) deamininase, and extracellular enzymes like chitinase which inhibited the phytopathogen. For the EPR4 strain, 16S rRNA gene sequencing was followed by NCBI - BLAST similarity showed the maximum sequence similarity (100%) with the species of Enterobacter (available on NCBI data base), and recognized as Enterobacter sp. EPR4 (GenBank accession number JN225424). The Enterobacter sp. EPR4 has the potential to be used as a biocontrol agent against S. sclerotiorum as well as a good plant growth promoter for common bean and other crops grown in India's Garhwal Himalaya.

Endophytic Trichoderma spp. can protect strawberry and privet plants from infection by the fungus Armillaria mellea.

Armillaria mellea is an important fungal pathogen worldwide, affecting a large number of hosts in the horticulture and forestry industries. Controlling A. mellea infection is expensive, labour intensive and time-consuming, so a new, environmentally friendly management solution is required. To this effect, endophytic Trichoderma species were studied as a potential protective agent for Armillaria root rot (ARR) in strawberry and privet plants. A collection of forty endophytic Trichoderma isolates were inoculated into strawberry (Fragaria × ananassa) plants and plant growth was monitored for two months, during which time Trichoderma treatment had no apparent effect. Trichoderma-colonised strawberry plants were then inoculated with A. mellea and after three months plants were assessed for A. mellea infection. There was considerable variation in ARR disease levels between plants inoculated with different Trichoderma spp. isolates, but seven isolates reduced ARR below the level of positive controls. These isolates were further tested for protective potential in Trichoderma-colonized privet (Ligustrum vulgare) plants where five Trichoderma spp. isolates, including two highly effective Trichoderma atrobrunneum isolates, were able to significantly reduce levels of disease. This study highlights the potential of plants pre-colonised with T. atrobrunneum for effective protection against A. mellea in two hosts from different plant families.

Calluna vulgaris as a Valuable Source of Bioactive Compounds: Exploring Its Phytochemical Profile, Biological Activities and Apitherapeutic Potential.

Calluna vulgaris, belonging to the Ericaceae family, is an invasive plant that has widely spread from Europe all across Asia, North America, Australia and New Zealand. Being able to survive in rigid soil and environmental conditions, it is nowadays considered to be of high nature-conservation value. Known for its nutritional and medicinal properties, C. vulgaris stands out for its varied physiochemical composition, spotlighting a wide range of biological activity. Among the most important bioactive compounds identified in C. vulgaris, the phenolic components found in different parts of this herbaceous plant are the main source of its diverse pro-health properties (antioxidant, anti-inflammatory, antimicrobial, chemoprotective, etc.). Nonetheless, this plant exhibits an excellent nectariferous potential for social insects such as honeybees; therefore, comparing the bioactive compounds observed in the plant and in the final product of the beehive, namely honey, will help us understand and find new insights into the health benefits provided by the consumption of C. vulgaris-related products. Thus, the main interest of this work is to review the nutritional profile, chemical composition and biological activities of the C. vulgaris plant and its related honey in order to encourage the future exploration and use of this health-promoting plant in novel foods, pharmacological products and apitherapy.

Role of Poly(ADP-Ribose) Polymerase (PARP) Enzyme in the Systemic Acquired Acclimation Induced by Light Stress in Phaseolus vulgaris L. Plants.

Plants are able to acclimate to environmental constraints through functional modifications that may also occur in tissues that are not directly exposed to stress. This process is termed “systemic acquired acclimation.” The present study aims to evaluate the involvement of PolyADP-ribose) polymerase (PARP) protein in the acclimation process to high light (HL) stress in Phaseolus vulgaris plants. For this purpose, some leaves located at the top of the plant, in the apical position, were directly exposed to HL (“inducing” leaves), while others on the same plant, distal from the top, continued to be exposed to growth light (“receiving” leaves) to verify the hypothesis that an “alert” message may be transferred from injured tissues to distal ones. Biochemical and eco-physiological analyses, namely PARP activity, H2O2 and water- and fat-soluble antioxidants (i.e., ascorbic acid, tocopherol, glutathione (GSH), phenols, carotenoids, etc.) content, and chlorophyll fluorescence measurements were performed on both “inducing” and “receiving” leaves. Even if no change in PARP expression was found, its activity increased in “receiving” unstressed leaves in response to the light stress duration experimented by “inducing” leaves, while antioxidant capacity declined. When the “receiving” leaves were exposed to HL, the PARP activity returned to the control value, while antioxidant capacity photosynthetic electron transport rate (Jf) decreased and increased, respectively, compared to Control. Our results seem to show an acclimation pathway triggered in remote tissues not yet subjected to stress, likely involving a reactive oxygen species wave activating the PARP enzyme in a mechanism still to be clarified. In addition, the increased tolerance of plants directly exposed to HL could implicate a boosted synthesis of soluble antioxidants accompanied by a reduction of PARP activity to reduce excessive consumption of NAD(P).

Endophytic Bacteria and Essential Oil from Origanum vulgare ssp. vulgare Share Some VOCs with an Antibacterial Activity.

Medicinal aromatic plants’ essential oils (EOs) are mixtures of volatile compounds showing antimicrobial activity, which could be exploited to face the emerging problem of multi-drug resistance. Their chemical composition can depend on the interactions between the plant and its endophytic microbiota, which is known to synthesize volatile organic compounds (VOCs). However, it is still not clear whether those volatile metabolites can contribute to the composition of the aroma profile of plants’ EOs. The aims of this study were to characterize medicinal plant O. vulgare ssp. vulgare bacterial endophyte VOCs, evaluating their ability to antagonize the growth of opportunistic human pathogens belonging to the Burkholderia cepacia complex (Bcc) and compare them with O. vulgare EO composition. Many of the tested endophytic strains showed (i) a bactericidal and/or bacteriostatic activity against most of Bcc strains and (ii) the production of VOCs with widely recognized antimicrobial properties, such as dimethyl disulfide, dimethyl trisulfide, and monoterpenes. Moreover, these monoterpenes were also detected in the EOs extracted from the same O. vulgare plants from which endophytes were isolated. Obtained results suggest that endophytes could also play a role in the antibacterial properties of O. vulgare ssp. vulgare and, potentially, in determining its aromatic composition.

Extracellular vesicles isolated from dsRNA-sprayed barley plants exhibit no growth inhibition or gene silencing in Fusarium graminearum

Numerous reports have shown that incorporating a double-stranded RNA (dsRNA)-expressing transgene into plants or applying dsRNA by spraying it onto their leaves successfully protects them against invading pathogens exploiting the mechanism of RNA interference (RNAi). How dsRNAs or siRNAs are transferred between donor host cells and recipient fungal cells is largely unknown. It is speculated that plant extracellular vesicles (EVs) function as RNA shuttles between plants and their pathogens. Recently, we found that EVs isolated from host-induced gene silencing (HIGS) or spray-induced gene silencing (SIGS) plants contained dsRNA-derived siRNAs. In this study, we evaluated whether isolated EVs from dsRNA-sprayed barley (Hordeum vulgare) plants affected the growth of the phytopathogenic ascomycete Fusarium graminearum. Encouraged by our previous finding that dropping barley-derived EVs on F. graminearum cultures caused fungal stress phenotypes, we conducted an in vitro growth experiment in microtiter plates where we co-cultivated F. graminearum with plant EVs isolated from dsRNA-sprayed barley leaves. We observed that co-cultivation of F. graminearum macroconidia with barley EVs did not affect fungal growth. Furthermore, plant EVs containing SIGS-derived siRNA appeared not to affect F. graminearum growth and showed no gene silencing activity on F. graminearum CYP51 genes. Based on our findings, we concluded that either the amount of SIGS-derived siRNA was insufficient to induce target gene silencing in F. graminearum, indicating that the role of EVs in SIGS is minor, or that F. graminearum uptake of plant EVs from liquid cultures was inefficient or impossible.