Marjana Regvar

• Professor
• Head of Botany and Plant Physiology at University of Ljubljana

Common buckwheat and Tartary buckwheat are pseudocereals and grow worldwide. Due to the high concentration of flavonoids, buckwheats are potential sources of smart food. Tartary and common buckwheat are traditionally grown in mountain regions of China, Korea, the northern parts of India, Bhutan, and Nepal. Plants that grow in high elevations are ex...

Hyperaccumulating plants can take up extraordinarily large concentrations of one or more metal(loid)s from the soil and accumulate it/them in the aboveground tissues without exibiting any visible toxicity symptoms. Among more than 700 plant taxa reported to have evolved this unique phenotype, the most common is the hyperaccumulation of nickel (Ni),...

Grapevine is an economically important crop, affected by major production losses due to high virus prevalence. Arbuscular mycorrhizal fungi (AMF) can reduce the impact of plant biotic stresses. However, hormonal response to the simultaneous presence of viruses and AMF remains largely unknown. In this study, we explored the potential of AMF to modif...

Field production of common beans benefit from root microbial associations, although they are generally considered to be weaker nitrogen fixers than other legumes. Therefore, the number of nodules on the roots of 64 accessions of the European common bean (Phaseolus vulgaris L.) and the relationship between the number of nodules per accession and oth...

Food producers actively seek effective seed-coating agents to ensure optimal antimicrobial protection and/or nutritional support for young plants. In this context, our study aimed to investigate the impact of various copper compounds on the germination and early growth stages of two important crops, common and Tartary buckwheat. Microparticles (MPs...

Climate change modifies environmental conditions, resulting in altered precipitation patterns, moisture availability and nutrient distribution for microbial communities. Changes in water availability are projected to affect a range of ecological processes, including the decomposition of plant litter and carbon cycling. However, a detailed understan...

The quality of molecular imaging by means of MeV primary ion-induced secondary ion mass spectrometry by coating with gold was evaluated on different reference organic molecules and plant samples. The enhancement of the secondary ion yield was evident for the majority of the studied analytes, reaching the highest values at gold thicknesses between 0...

Fungi are the leading cause of plant diseases worldwide and are responsible for enormous agricultural and industrial losses on a global scale. Cold plasma (CP) is a potential tool for eliminating or inactivating fungal contaminants from biological material such as seeds and grains. This study used a low-pressure radiofrequency CP system with oxygen...

With the aim to characterize changes caused by grapevine leafroll-associated virus 3 (GLRaV-3) singly or in coinfection with other viruses and to potentially determine genotype-specific or common markers of viral infection, thirty-six parameters, including nutrient status, oxidative stress parameters, and primary metabolism as well as symptoms inci...

The concept of terroir relates the sensory attributes of wines attributable to the environmental conditions of the grapevines, and therefore it represents an important descriptor of the connection between wines and their origins. In ongoing efforts to improve the monitoring and geochemical fingerprinting of grapevine products, knowledge of the vari...

Modern botanical fungicides should be non-toxic and readily available. Hydrosols are by-products of essential oil distillation with a large potential market size. They are, therefore, suitable natural candidates for effective fungicide development. Improving grain quality and safety during storage are significant challenges in the contemporary worl...

Buckwheat is an alternative crop known for its many beneficial effects on our health. Fungi are an important cause of plant diseases and food spoilage, often posing a threat to humans and animals. This study reports the effects of low-pressure cold plasma treatment on decontamination and germination of common (CB) and Tartary buckwheat (TB) grains....

Common reed (Phragmites australis) has high biomass production and is primarily subjected to decomposition processes affected by multiple factors. To predict litter decomposition dynamics in intermittent lakes, it is critical to understand how communities of fungi, as the primary decomposers, form under different habitat conditions. This study repo...

In view of the ever-growing human population and global environmental crisis, new technologies are emerging in all fields of our life. In the last two decades, the development of cold plasma (CP) technology has offered a promising and environmentally friendly solution for addressing global food security problems. Besides many positive effects, such...

The contribution of 1,8-dihydroxy naphthalene (DHN) melanin to cadmium (Cd) tolerance in two dark septate endophytes (DSE) of the genus Cadophora with different melanin content was investigated in vitro. The DSE isolate Cad#148 with higher melanin content showed higher tolerance to Cd than the less melanised Cad#149. Melanin synthesis was significa...

Crop seeds are frequently colonised by fungi from the field or storage places. Some fungi can cause plant diseases or produce mycotoxins, compromising the use of seeds as seeding material, food or feed. We have investigated the effects of cold plasma (CP) on seed germination and diversity of seed-borne fungi in common and Tartary buckwheat. The see...

Crops’ wild relatives host a wide range of microorganisms, including some beneficial species that are not found or are under-represented in the domesticated crops. Our goal was to study the underexplored composition of root-associated fungal communities in endangered wild grapevines. We found high taxonomic diversity representing multiple trophic g...

The data presented in this article are related to the research article entitled “Root-associated community composition and co-occurrence patterns of fungi in wild grapevine”. This dataset documents the diversity of endophytic and rhizoplane fungi found on the roots of 38 wild grapevine plants growing at four locations (Krka, Neretva, Psunj and Pakl...

Plants are a source of nutrient (organic or inorganic) compounds. The transport and localization of diverse nutrient compounds in different plant tissues or cell‐types have received considerable attention. The advancement in imaging technologies has generated crucial information about the differential nutrient accumulation pattern in the storage or...

The genetic diversity and relationship between wild (Vitis vinifera L. subsp. sylvestris (Gmel.) Hegi and cultivated (V. vinifera L. subsp. vinifera) grapevine in the western Balkan region and Central Europe have not been studied together previously, although this area has a rich viticultural past. Here, we studied wild grapevine populations sample...

Tartary buckwheat (Fagopyrum tataricum Gaertn.) is a gluten-free pseudo-cereal crop with a grain nutrient profile that makes it an excellent alternative foodstuff. The distribution of calcium (Ca), magnesium (Mg), phosphorus (P) and sulphur (S) was investigated by micro-PIXE (particle induced X-ray emission) to resolve allocation and concentration...

BACKROUND AND AIMS Phytoremediation is one of the possible tools for reducing bioavailability of toxic metals in soil. Dark septates endophytes (DSE) are often dominant colonizers on plant roots in such environments, which indicates the importance of their ecological role. In vitro studies have confirmed their high tolerance to heavy metals (3) and...

Mycorrhizal and organic amendments specifically affected S, Ca, Mg and Mn concentrations of common buckwheat grain. • Positive correlations of elements between tissues point to seed coats as element resorption pools within grain. • Element fingerprints of flour enabled questioning their quality. ABSTRACT We investigate the prospect of increased min...

During tea preparation mineral elements are extracted from the dried leaves of tea (Camellia sinensis (L.) Kuntze) plants into the solution. Micro-particle induced X-ray emission was employed to investigate the spatial distribution of magnesium (Mg), calcium (Ca) and manganese (Mn) in the young and old leaves of tea plants grown in the absence and...

As sessile organisms, plants must constantly adapt to environmental changes. Plant performance is related to availability of light, water, and mineral nutrients, which is especially important in agricultural systems, where minerals are removed from the fields at harvest. Mineral nutrients are also essential for the normal functioning of animal and...

Key message Element profile signatures of needle tissues differentiated four tissues: epidermis (main contributor: calcium), endodermis (main contributors: magnesium, sulphur and manganese), mesophyll (main contributor: potassium), and transfusion parenchyma (main contributor: zinc). Abstract Distribution of elements in cross-sections of Scots pin...

Plant litter decomposition in intermittent dry and wet habitats share decomposition mechanisms of both dry land and submerged habitats. The aims of the present study were therefore to compare fungi communities on the decomposing plant material regarding the water regime of the location. Furthermore we wanted to evaluate the effects of the water reg...

High levels of arbuscular mycorrhizal fungi colonisation of 90–100%, as well as high vesicular and arbuscular colonisation were found in the roots of the rare and endangered wild grapevine (Vitis vinifera subsp. sylvestris) along the Neretva River in southwestern Bosnia and Herzegovina, surpassing colonisation in region vineyads.

Pt nanoparticles (NPs) are directly emitted into air from human activities, contributing to the pollutant load of plants and posing risks to food safety. Foliar surface characteristics affect particle interception...

The aim of this paper is to review principles and potential application of micro-proton induced X-ray emission (micro-PIXE), synchrotron-based micro-X-ray fluorescence (micro-XRF) and inductively coupled plasma-mass spectrometry (ICP-MS) hyphenated with pulsed laser ablation (LA) for analysing plants and plant materials to elucidate feature of cons...

Wetlands are ecosystems where the water regime is the main factor that shapes the physical, chemical and biological characteristics. Wetland plants are rooted in water-saturated soils that are frequently anoxic. In spite of this, the rhizosphere can be oxygenated due to the aerenchyma of the wetland plants, which enable active ventilation of roots,...

Viticulture is an important agronomic sector that has the potential to greatly benefit by improvements in our understanding of grapevine cultivation. Although conventional viticulture relies to a great extent on pesticide and fertilizer application, more sustainable approaches involve management practices that favor plant–fungus interactions that h...

The new ecological approach to viticulture emphasises ecologically sound grape production and recognizes the importance of grapevine (Vitis vinifera) interactions with soil microbial communities. Due to different viticulture measures, distinctly different microbial communities can form, which affects the potentially beneficial interactions with the...

Two plant pathogenic fungi, Botrytis cinerea and Alternaria alternata, isolated from crop plants, were exposed to Cu in ionic (Cu²⁺), microparticulate (MP, CuO) or nanoparticulate (NP, Cu or CuO) form, in solid and liquid culturing media in order to test fungal response and toxic effects of the mentioned compounds for the potential use as fungicide...

Buckwheat is a gluten-free crop with great potential as a cereal substitute in diets. We investigated how processing of grains into groats (hydrothermal processing to remove the husk) and sprouts (7-day-old seedlings) affects mineral element concentrations in two buckwheat species, Tartary buckwheat (Fagopyrum tataricum Gaertn.) and common buckwhea...

The hypothesis of this study is that the variable hydrological regime of intermittent lakes and wetlands affects the primary productivity, decomposition and root fungal colonisation of Phragmites australis, with effects on the whole ecosystem metabolism. The above-ground biomass of reed stands was monitored in littoral and riparian stands of Lake C...

Seed-associated fungal communities affect multiple parameters of seed quality at all stages of production, from seed development to post-harvest storage and germination. We therefore investigated the diversity and dynamics of fungal communities in the seeds of common buckwheat (Fagopyrum esculentum) and Tartary buckwheat (F. tataricum) from harvest...

Background Arbuscular mycorrhizal fungi (AMF) are among the most important beneficial fungal root endophytes, and are known to colonise the roots of the majority of land plants, including grapevines. Similar to other plant species with low root densities or with relatively coarse fine roots, grapevines appear to be reliant on AMF colonisation for n...

Main factors affecting mineral composition (ionome) of grains are soil mineral availability, bioaccumulation capacity of plant species and plant-microbe interactions. We investigated the feasibility of grain biofortification with two commercial organic fertilizer treatments (Symbivit; S) and Bioaktiv; B) in wheat (Triticum aestivum L.), common buck...

Common buckwheat is known by high contents of bioactive substances from the fibers, vitamins and flavonoids with strong antioxidant activities, which make it functional food (Kreft et al., 2006). Studies on buckwheat plants are mostly focused on phylogeny, genetics, production, its secondary metabolites and its nutrition value, only few had touched...

According to recent molecular analyses of Salicornia, we revised the annual glassworts from the Croatian coast, classified until now only as Salicornia europaea. Two species, a diploid Salicornia patula and a tetraploid S. emerici were recognized. They can be easily distinguished by floral characters, but not only by their habitus, which varies ext...

Maize root residues that remain in the field after harvesting are a source of water-soluble compounds, which can inhibit growth of succeeding maize crops through autotoxicity. The aim of this study was to test whether the formation of symbiosis between maize and arbuscular mycorrhizal fungi (AMF) alle-viates negative effects of autotoxicity. Maize...

Background and aims Dark septate endophyte (DSE) fungi are the most frequent colonists on the roots of Salix caprea in highly metal-contaminated soils. The present study was performed to obtain insights into the physiology and potential role(s) of DSE fungi for Salix caprea growing in metal-enriched sites. Methods Fungal isolates from S. caprea ro...

Violets from metal-enriched soils have controversially been described as both heavy-metal accumulators and excluders in the literature. The present study solves the issue for violets of the section Melanium (zinc violets, Viola lutea ssp. calaminaria and V. lutea ssp. westfalica; hartsease or wild pansy, Viola tricolor; and mountain pansy, V. lutea...

The different buckwheat species are gluten-free pseudocereals, and they are amongst the most important alternative foodstuffs as they have an excellent nutrient profile. The grain of tartary buckwheat (Fagopyrum tataricum Gaertn.) is known to be rich in antioxidants (especially rutin) and mineral elements. In addition to the spatial distributions o...

Bulk element concentrations of whole grain and element spatial distributions at the tissue level were investigated in wheat (Triticum aestivum) grain grown in Zn-enriched soil. Inductively coupled plasma mass spectrometry and inductively coupled plasma optical emission spectrometry were used for bulk analysis, whereas micro-proton-induced X-ray emi...

Recently we completed a construction of a cryostat at Jožef Stefan Institute (JSI) nuclear microprobe enabling us to analyze various types of biological samples in frozen hydrated state using micro-PIXE/STIM/RBS. Sample load-lock system was added to our existing setup to enable us to quickly insert a sample holder with frozen hydrated tissue sample...

Optimisation of the concentrations of essential mineral elements in staple grain diet and reduction in non-essential and potentially toxic elements would considerably alleviate mineral malnutrition and improve the health of humans. Here, wheat (Triticum aestivum L.) plants were biofortified with Zn and/or Se to determine the changes across 36 eleme...

Background and aims Distinct metal distribution pat-terns within leaves of metal hyperaccumulating plants are repeatedly observed however, the presumable role of key structural biochemical molecules in determin-ing and regulating their allocation remains largely unknown. We aimed to characterise in a spatially resolved manner the distribution of th...

There are several metal-hyperaccumulating species within Brassicaceae, which are also characterized by high glucosinolates content, which are secondary compounds with pronounced effects in plant – biotic interactions. It is generally believed that glucosinolates prevent the formation of mutualistic symbioses with arbuscular mycorrhizal fungi. Arbus...

Understanding the uptake, accumulation and distribution of toxic elements in plants is crucial to the design of effective phytoremediation strategies, especially in the case of complex multi-element pollution. Using micro-proton induced X-ray emission, the spatial distribution of Na, Mg, Al, Si, P, S, Cl, K, Ca, Mn, Fe, Zn, As, Br, Rb, Sr, Cd and P...

Metals cannot be chemically degraded; rather they need to be physically removed in cost-intensive and technically complex procedures, highlighting the need for sustainable cost efficient remedial actions. In the last decade, plant-based technologies involving biological processes, including plant uptake, transport, accumulation and sequestration of...

The elemental composition of cereal and pseudocereal grain is believed to significantly affect the portions of the minerals supplied for particular human populations. Therefore, care needs to be taken to improve the availability of the essential elements and to decrease unwanted metal accumulation in edible plant parts. In the present study, we hav...

The colonisation and diversity of arbuscular mycorrhizal fungi (AMF) on roots of grapevines were investigated in production vineyards located along a 500-km-long stretch of karst along the coast of the Adriatic Sea. AMF communities on roots of grapevines were analysed using temporal temperature gel electrophoresis and sequencing of the 18S and inte...

Diverse physiological, biochemical and morphological adaptations enable plants to survive in extreme saline environments where osmotic and ionic stresses are limiting factors for growth and development. Distribution patterns of salt ions in the leaves of halophytes, plants able to withstand extraordinary high levels of these elements, may reflect t...

A better understanding of the mechanisms that govern copper (Cu) uptake, distribution and tolerance in Brassica carinata plants in the presence of chelators is needed before significant progress in chelate-assisted Cu phytoextraction can be made. The aims of this study were therefore to characterise (S,S)-N,N'-ethylenediamine disuccinic acid (EDDS)...

Typha latifolia is a plant species widely used for phytoremediation. Accumulation, localization and distribution of Pb and mineral nutrients were investigated in roots, rhizomes and leaves of Typha latifolia grown at 0, 50, 100 and 250 μM Pb concentrations in a pot experiment under controlled conditions. Bulk elemental concentrations were determine...

In the present study, we have evaluated the effects of increased UV-B radiation that simulates 17% ozone depletion, on fungal colonisation and concentrations of rutin, catechin and quercetin in common buckwheat (Fagopyrum esculentum) and tartary buckwheat (Fagopyrum tataricum). Induced root growth and reduced shoot:root ratios were seen in both of...

Cytokinins are known to attenuate defence responses of plants after elicitor application or inoculation with fungi. To evaluate their role in the regulation of colonisation of Norway spruce (Picea abies) seedlings with mycorrhizal and pathogenic fungus, we analysed the effects of zeatin riboside (ZR) on: i) growth of ectomycorrhizal fungus Pisolith...

Metal-hyperaccumulating plants can accumulate extraordinarily high quantities of certain metal ions in their leaves without suffering from toxic effects, thus allowing normal functioning of their metabolic processes. Metal tolerance is provided by efficient metal-detoxification mechanisms that operate at the organ, tissue, and cell levels. As only...

Information on localization of Al in tea leaf tissues is required in order to better understand Al tolerance mechanism in this Al-accumulating plant species. Here, we have used low-energy X-ray fluorescence spectro-microscopy (LEXRF) to study localization of Al and other low Z-elements, namely C, O, Mg, Si and P, in fully developed leaves of the te...

Mature developed seeds are physiologically and biochemically committed to store nutrients, principally as starch, protein, oils, and minerals. The composition and distribution of elements inside the aleurone cell layer reflect their biogenesis, structural characteristics, and physiological functions. It is therefore of primary importance to underst...

The elemental composition of specific fractions of cereal and pseudocereal grains can be roughly estimated after milling. Alternatively, the elemental localization of cross-sectioned grains can be quantitatively analyzed by microproton induced X-ray emission (micro-PIXE), taking advantage of high elemental sensitivity and low lateral resolution. We...

Ecosystems worldwide are threatened with the extinction of plants and, at the same time, invasion by new species. Plant invasiveness and loss of species can be caused by similar but opposing pressures on the community structures. Arbuscular mycorrhizal fungi (AMF) can have multiple positive effects on plant growth, productivity, health, and stress...

Environmental conditions in wetlands were long thought to suppress mycorrhizal fungi and it has been assumed that mycorrhiza in wetlands is limited and is of little significance. This contribution summarises the presence of arbuscular mycorrhizal (AM) fungi and dark-septate endophytes (DSE) in different habitats of the intermittent Lake Cerknica. M...

A detailed localisation of elements within leaf tissues of hydroponically grown Cd/Zn hyperaccumulator Thlaspi praecox (Brassicaceae) was determined by micro-PIXE at Jožef Stefan Institute (Ljubljana, Slovenia) in order to study accumulation patterns of Cd and other elements in the case of a single metal (Cd) pollution. Plants were treated with inc...