9. 2. 2023 Gyan Singh Shekhawat (Department of Botany (UGC-CAS), Jai Narain Vyas University, Jodhpur 342001, India), 13:00, Main Conference Room IB PSBC SAS

Heme oxygenase (HO): A functionally diverse enzyme of photosynthetic organisms and its role in cellular signaling, metabolism and plant defense

Heme oxygenase (HO) degrades free haem released from haem proteins with the generation of ferrous iron (Fe2+), biliverdin-IXa (BV-IXa), and carbon monoxide (CO). The mechanism of haem cleavage has been conserved between plants and other organisms even though the function, subcellular localization, and cofactor requirements of HO differ substantially. The crystal structure of HO1, a monomeric protein, has been reported in mammals, bacteria, and cyanobacteria, but no such reports are available for higher plant HOs except a predicted model for pea HO1. Along with haem degradation, HO performs various cellular processes including iron acquisition/ mobilization, phytochrome chromophore synthesis, cell protection, and stomatal regulation. To date, four HO genes (HO1, HO2, HO3, and HO4) have been reported in plants. HO1 has been explored in cell metabolism; however, the divergent roles of the other three HOs are less known. The transcriptional up-regulation of HO1 in plants responds to many conditions, such as light, UV, iron deprivation, reactive oxygen species (ROS), abscisic acid (ABA), and haematin. Recently the HO1/CO/NO system has gained more attention due to its physiological cytoprotective role in plants. The study focuses on the recent advances made in plant-HO research involving its role in abiotic stress (Heavy metal/Salt) and physiological, biochemical, and molecular aspects of Heme oxygenase.

19. 1. 2023 Marek Semelbauer, 13:00, Main Conference Room IB PSBC SAS

How and why to save wild pollinators

Scientists have documented the decline of terrestrial insects in recent decades in developed countries, such as Great Britain, the Netherlands or Germany. Insects are an important link in terrestrial and freshwater ecosystems, and among the best-known services they provide to human society is pollination. Traditionally, much of pollination was attributed to the honey bee, but much current scientific knowledge emphasizes the importance of wild pollinators. In addition, there is growing consensus that a high concentration of bee colonies can have a negative impact on populations of wild pollinators. The decline of pollinators also raises the question of how to properly protect them. Pollinators are mainly inhabitants of open or mosaic landscapes. The range of possible measures is very wide – from the creation of urban meadows, through the maintenance of former military training grounds by large grazers to the restoration of wood pastures or occasional burning.


15. 12. 2022 Judita Zozomová, 13:00, 5th Floor Conference Room IB PSBC SAS

Exploring the evolution of polyploid species complexes – a phylogenomic approach. Case studies on Cardamine and Alyssum (Brassicaceae)

This presentation will be focused on polyploid species complexes. When studying their evolution, both divergent (bifurcating) and reticulate evolutionary patterns must be considered and reconstructed. In recently evolved species complexes, retention of ancestral variation also complicates phylogenetic inferences and leads to similar patterns of gene tree-species tree discordance as interspecific gene flow. Conventional genetic markers used in the past (e.g., AFLPs, Sanger sequencing of selected genes) often failed to elucidate the evolution of such species complexes. Here, I will present case studies from the genera Cardamine and Alyssum and demonstrate the application of an NGS technique, called Hyb-Seq. This technique combines target enrichment and genome skimming, yielding sequence data from hundreds of low-copy nuclear genes along with high-copy DNA (e.g., chloroplast genomes). Bioinformatic processing of sequence reads from allopolyploid genomes is challenging because it requires assembly of allele sequences, their assignment to homeologs (parental gene copies), and sorting of homeologs to subgenomes, followed by construction of a phylogenetic tree or network. We have used and compared several bioinformatic tools that have allowed us to infer a robust phylogeny of diploid species and reconstruct both auto- and allopolyploid speciation events. Future plans and directions for our research will also be outlined.

1. 12. 2022 Ladislav Pekárik, 13:00, Main Conference Room IB PSBC SAS

Should we eat fish (only) during Christmas?

What is the amount of fish consumed in Slovakia compared to the rest of the world? Where fish is consumed during Christmas and should we release back the Christmas carp at all? What does the fish’s environment look like, where and how do they live, and what are their life cycle and overall importance for society? Are fish overexploited? Which species should be avoided due to the drastic population decrease? And is every fish suitable for consumption? What dangerous substances can be accumulated in their tissues? Which rivers in Slovakia are still polluted?

27. 10. 2022 Richard Hrivnák, 13:00, via Zoom application

Vascular plant species richness of beech forests along altitudinal gradient and its environmental background

The study of plants’ alpha diversity (species richness) along altitudinal gradient has been interesting for the scientific community for a long-time. Response of species richness along the gradient is various – increasing, decreasing, flat or unimodal mainly due to the length of the altitudinal gradient. Specifically, a U-shaped pattern was identified in monodominant forests such as beech forests with Fagus sylvatica dominance. Our study of the effects of environmental variables and dendrometric characteristics on species richness showed a „hard fight for resources” and mutual competition of trees and understory plants both above and below the soil surface. Beech tree fine root mass, canopy openness, soil nitrogen, and C/N ratio, the interaction between tree fine root mass and stoniness, and stand structural diversity explain the variation of understorey species richness.

13. 10. 2022 Dušan Senko & Tomáš Figura, 13:00, via Zoom application

Use of in vitro in nature conservation

In recent decades, there has been a drastic decrease in the number of orchids (Orchidaceae) worldwide, and Slovakia is no exception. Individual localities are threatened by succession or intensification. One of the possibilities to reverse the decline can be the strengthening of populations with plants grown in vitro. Asymbiotic cultivation in vitro is practically the only method for propagating terrestrial orchids. In contrast to natural conditions, where carbonaceous compounds are supplied by mycorrhizal fungi, in symbiotic in vitro cultivation, the source of carbon is most often sucrose in the nutrient medium, which replaces the presence of mycorrhizal fungi. Seed germination and protocorm development depend on physical factors, the method of surface sterilization of seeds or the presence of growth regulators in the culture media. Cultivation of protocorms of terrestrial European species usually takes place in the dark, sometimes with the necessity of cold stratification. During the growth, the seedlings are subcultivated several times in in vitro conditions, followed by the transfer of the plants from the sterile in vitro environment to non-sterile conditions – to the pots, where they remain for at least one growing season.

29. 9. 2022 Darina Peterková, 13:00, Main Conference Room IB PSBC SAS

The role of the AtSYT1 gene in the response to salt stress: a proteomic analysis

Soil salinization affects plant growth and agricultural production. Accumulation of NaCl in soil leads to the global annual loss of 10 million hectares of agricultural land. Plants have evolved various adaptive mechanisms to salinity and several genes involved in responses to this abiotic stress have been characterized. Our research focus on plant synaptotagmins. Synaptotagmins are membrane proteins with a characteristic N-terminal transmembrane region, a linker of variable length and a tandem C2 domain which is able to bind Ca2+. They were originally defined as calcium sensors in vesicular transport in animal nerve cells. Six synaptotagmins have been identified in Arabidopsis thaliana, and AtSYT1 is the most and universally expressed of them. This protein is involved in several responses to biotic and abiotic stresses, but the exact mechanisms are still unknown. In the last period, we used atsyt1 mutants to study how the absence of the AtSYT1 protein affects the efficiency of photosynthesis. Furthermore, we used liquid chromatography-mass spectrometry to analyze how salt stress and the absence of the AtSYT1 gene function manifests itself on the spectrum of proteins in the roots of sprouts under in vitro conditions. In my presentation, I will summarize the results of this proteomic analysis and outline further research directions in this area.

23. 6. 2022 Luca Paoli, 13:00, Main Conference Room IB PSBC SAS

Air pollution in Slovakia: a story told by lichens, with a focus on threatened species

In the second half of the twentieth century, the territory of Central Europe (including Slovakia), has been exposed to increased amounts of emissions, mainly SO2, NOx and heavy metals. The emissions and subsequent air pollution resulted in negative impacts on human health and the environment, until the changing of political and socio-economic situation after 1989 in Central and Eastern Europe led to a radical decrease of emissions. Given their ability to take up atmospheric pollutants from the surrounding environment, lichens are profitably used as biomonitors of air quality. A selection of studies carried out in Slovakia and devoted to the causal relation between environmental pollution and lichens are presented, with reference to the period 1960–2020, encompassing the use of biodiversity and bioaccumulation techniques as well as ecophysiological parameters in native and transplanted lichens. The review includes pioneering up to recent monitoring studies of air pollution effects in urban and industrial areas, monitoring changes in species distribution between the nineteenth and twentieth centuries due to atmospheric pollution and habitat alteration, the retreat of sensitive species (with a focus on the model species Lobaria pulmonaria), as well as recent regional and large-scale biomonitoring in forests. Beside urban pollution, the topics cover copper and mining activities, mercury pollution, magnesite and aluminium production, steel and cement industry.

16. 6. 2022 Michal Slezák, 13:00, Main Conference Room IB PSBC SAS

Species diversity of vascular plants in floodplain forests – temporal and spatial changes

Floodplain forests are considered an important component of riverine ecosystems. Their plant species assemblages are shaped by natural disturbance (flooding) regime, hierarchy of resource utilization (mainly soil water and nutrients) and interspecific interactions. The synergistic effect of these drivers promotes the development of a typical mosaic structure with a species-rich understory layer. It is composed of plant species with different ecological niches. Our last research activities aimed to test the predictive power and effect of two topographic indices, as proxies for disturbance (stream power index) and productivity (wetness index) levels, on the (α-) diversity patterns of all vascular plants and their functional groups (ferns, woody species, Red List and alien species, neophytes) in riparian floodplain forests. The results indicate that higher flooding-induced disturbances associated with light availability increased the number of all species. The positive effect of flooding disturbances was diminished towards more productive sites. The response of species diversity to both predictors depends on species group. Re-sampled dataset of black alder swamp forests was used to analyse the effects of increasing light availability on species coexistence, i.e. we evaluated temporal changes in species distribution and diversity along a micro-topographic (moisture) gradient. We found that the species diversity and total plant cover increased significantly due to positive effect of light conditions. The competition-facilitation relationship did not change significantly over time.

2. 6. 2022 Ľubica Liptáková, 13:00, Main Conference Room IB PSBC SAS

Reactive oxygen species in the stress response of plants

The main mechanism of cadmium toxicity is oxidative stress, which is manifested by an imbalance in the production and removal of reactive oxygen species (ROS). Depending on their concentration, ROS have a dual function in stress responses. At low concentrations induced by mild stress, ROS are signaling components to activate defense responses. Due to strong stress conditions, ROS production is increasing. Increasing their concentration caused by strong stress, exceeding the capacity of the antioxidant system, is responsible for oxidative damage or even lethal processes. Therefore, it is important to study the mechanisms regulating ROS, necessary for the protection of cells, tissues and the whole organism, leading to an increase in plant tolerance to adverse conditions. Several publications show that mitochondria are the site of increased ROS production in metal-exposed roots, and alternative oxidase activation regulates ROS production during various stress conditions. We used Western blotting to detect an alternative oxidase. The early increase of alternative oxidase levels indicates that the reduction of mitochondrial superoxide production is important in the response of the apical parts of the barley root to severe cadmium stress.

26. 5. 2022 Katarína Valentovičová, 13:00, Main Conference Room IB PSBC SAS

Stanovenie aktívnych foriem kyslíka v intaktných koreňoch. Ako sa vyhnúť falošne pozitívnej reakcii?

12. 5. 2022 Marek Slovák, 13:00, Main Conference Room IB PSBC SAS

Rola hybridizácie a introgresie v evolúcii rodu Soldanella

Hybridization is a key mechanism involved in lineage diversification and speciation, especially in ecosystems that experienced repeated environmental oscillations. Recently radiated plant groups, which have evolved in mountain ecosystems impacted by historical climate change, provide an excellent model system for studying how gene flow can drive but also prevent speciation. Using a combination of organellar and nuclear genomic data with a cytogenetic approach (FISH), we investigated the effects of hybridization and introgression on the evolution and speciation of the European Alpine System-dwelling genus Soldanella (snowbells, Primulaceae). We tested whether (1) introgression occurred recurrently during the evolutionary history of the genus; (2) Carpathian and Balkan species that usually feature large ecological amplitude have been affected by hybridization more than the widespread alpine zone-dwelling snowbell species; and (3) hybridization contributed to the speciation of S. alpina on the one hand and triggered the break down of species boundaries in Carpathian species on the other hand. We found that the pervasive introgression has occurred among ancestral lineages of snowbells and has persisted throughout the entire evolutionary history of the genus, regardless of the ecology or distribution range size of the affected species. The highest extent of introgression has been detected in the Carpathian species, which is also reflected in their extensive karyotype variation. Historical introgression occurred even between species with dysploid and euploid cytotypes, assumed to be reproductively isolated. The magnitude of introgression detected in snowbells is unprecedented in other mountain genera of the European Alpine System investigated hitherto. Our study stresses the creative evolutionary role of hybridization in facilitating but also impeding speciation and diversification processes.

5. 5. 2022 Martin Šafránek, 13:00, Main Conference Room IB PSBC SAS

Heterologická expresia LG3 domény DEK1

DEK1 je veľký multidoménový proteín o veľkosti 240 kDa, pričom jeho primárna aminokyselinová sekvencia si zachovala konzervovanú modulárnu štruktúru naprieč suchozemskými rastlinami. Predpokladá sa, že DEK1 pozostáva z dvoch hlavných topologických segmentov, ktoré sú dôležité pre jeho správnu funkciu: 1) membránového segmentu, ktorý je prerušený 300 aminokyselinovou slučkou a 2) cytosolickej časti, ktorá obsahuje linker s LG3 a konzervovanou kalpaínovou doménou. Kalpaínová doména DEK1 pozostáva z CysPc, charakteristickej katalytickej domény a regulačnej C2L domény. Aj napriek dlhoročnému štúdiu DEK1 stále nie je odhalený presný mechanizmus funkcie a ani samotná 3D štruktúra. K tomu, aby sme sa mohli priblížiť k tomuto cieľu, je potrebné získať proteín v čo najvyššej miere a hlavne čistote. Voľba vhodného vektora, či optimalizácia heterologickej expresie patria k základným krokom získania nadexprimovaného solubilného proteínu. Kryštalografická analýza na odhalenie 3D štruktúry zas vyžaduje získaný proteín v čo najvyššej čistote a teda je nutné vhodne zvoliť kombinácie chemicko-fyzikálnych purifikačných metód. Získanie podrobnej kvartérnej štruktúry je cesta nielen k porozumeniu funkcie proteínu, ale tiež k pochopeniu interakcií proteínu so substrátmi.

21. 4. 2022 Katarína Skokanová, 13:00, via Zoom application

Will the invasive spreading of Solidago canadensis be affected byhybridization with the native S. virgaurea?

Hybridization between native and alien congeners may pose a serious threat to biodiversity and negatively affect native flora. In our ongoing research, we focus on Solidago ×niederederi, which has originated through spontaneous hybridization between the invasive alien S. canadensis and native S. virgaurea. This hybrid was first recorded at the very end of the 19th century, recently its occurrence is reported in 17 European countries and we have also discovered 8 sites in Slovakia. Our research aimed: 1) to survey historical circumstances of hybrid discovery (resulting in its lectotypification), 2) to summarize its current distribution and habitat preferences, 3) to test the effectiveness of flow cytometry for detecting hybrid plants of S. ×niederederi, 4) to confirm the hybrid origin and to identify the maternal species by analyses of sequences of the ITS region of nrDNA and the rpS15-ycf1 spacer of cpDNA, 5) to detect direction and frequency of hybrid formation and backcrossing by flow cytometry analyses of the progeny of hybrid and parental plant. Our findings suggest that intogressive hybridization of highly invasive S. canadensis with S. virgaurea adapted to a wide range of local conditions could create even better-adapted and thus potentially more invasive phenotypes.

14. 4. 2022 Karol Marhold, 13:00, via Zoom application

Biodiversity informatic resources on the internet

According to Wikipedia, biodiversity informatics is the application of informatics techniques to biodiversity information for improved management, presentation, discovery, exploration and analysis. Most of us use its products in our every-day life. In the nomenclature practice, probably most important database project is the International Plant Names Index (IPNI), comprising all validly published species names, and for last dozens of years also infraspecific ones. Other databases, providing authoritative lists of accepted names and synonyms, have often limited geographical coverage or they are in the various stages of development. From among them, Tropicos, Euro+Med PlantBase, The Plant List, Plants of the World online or World Flora Online should be mentioned. Of particular importance are digital libraries, as Biodiversity Heritage Library, Biblioteca Digital (Real Jardín Botánico, Madrid) or Botanicus (Missouri Botanical Garden). Herbarium collections are often presented in digital form, either by individual institutions or by the portal JSTOR Global Plants, providing access to almost 3 million type specimens and other important collections from more than 300 institutions worldwide. Database of Global Biodiversity Information Facility (GBIF) comprises more than 1.5 billion distribution records on plants and animals, collection based or observations. Although data are of various quality, it is the most important information resource for biodiversity studies and applications.



9. 12. 2021 Beloslava Genova (University of Plovdiv) & Kiril Vassilev (Bulgarian Academy of Sciences), 13:00, via Zoom application

Recent status of vegetation research in Bulgaria and a collaborative study of the Danube floodplain forests

During the last six years, there has been a significant increase in the knowledge of the vegetation diversity in Bulgaria. An efficient municipality-based sampling and subsequent vegetation classification approach have been adopted. More than 8000 vegetation plots have been sampled (ca. 37% of all Bulgarian vegetation plots) recently. Vegetation classification resulted in the discovery of many new syntaxa. In addition, habitat mapping on a scale of 1:5000 was done. Thirteen percent of the territory of the country was re-investigated. A Bachelor’s thesis focusing on the Riparian forest vegetation in the Central and Western Rhodope mountains was elaborated as part of this work. Similarly, a Master thesis focusing on the diversity of hygro- and hydrophytic vegetation of two municipalities is in progress. Currently, cooperation between Bulgaria and Slovakia is taking place as a part of a research, which compares natural floodplain forests and artificial Populus plantations alongside the watercourse of the Danube river. Invasibility of both native and planted habitats has been compared and will be interpreted on a European scale. In addition, a new collaboration about habitat verification from the NaturaSat software in Bulgaria has recently started.

7. 10. 2021 Valerii Darmostuk, 13:00, via Zoom application

Lichenicolous fungi [Department of Botany, Kherson State University, Ukraine, SAIA fellowship June – October 2021]

Department of Botany, Kherson State University was founded in 1917 as the Cabinet of Natural History («Kabinet Pryrodoznavstva») which later became a full-fledged department. Currently it covers three main research areas: 1) vascular plants (invasive plants, urban flora, geobotany, other research related to dry grassland), 2) bryology (mosses of Eastern Europe), and 3) lichenology (lichens and their communities, lichenicolous fungi). Herbarium of KSU (KHER) keeps approximately 15 000 specimens of lichens and fungi as well as 15 000 specimens of plants and 7 000 specimens of mosses. Lichenicolous fungi have been actively studied at the department for the last 5 years within the topic of my PhD study titled “Lichenicolous fungi of the steppe zone of Ukraine”. As a result, 155 species of lichenicolous fungi and 13 species of lichenicolous lichens were reported for the study area. Among them, 96 species have been registered for the territory of the Ukrainian steppe zone for the first time. Five species were described as new for science species. 41 species of lichenicolous fungi and 3 species of lichenicolous lichens were for the first time reported to Ukraine, 9 species were new to Western Europe and 3 species were new to Europe. My current research focused on diversity, distribution and ecology of lichenicolous fungi of Eastern Europe as well as a phylogeny of lichenicolous Hypocreales (genus Pronectria, Xenonectriella). Our research in PSBC SAS is focused on diversity of lichenicolous fungi on genus Solenopsora. We examined the thalli of members of the lichen genus Solenopsora (Leprocaulaceae) to learn more about their potential to host symptomatic lichenicolous fungi. Altogether, 571 specimens were screened, out of which eighty specimens yielded lichenicolous fungi (nine taxa of lichenicolous fungi and one parasitic lichen).

9. 9. 2021 Viktor Demko, 13:00, via Zoom application

Plant calpain DEK1 governs developmental transitions in plants and is regulated at multiple levels

Calpains are tightly regulated cysteine proteases with essential functions in eukaryots. Best characterized are mammalian cytosolic calpains that have been implicated in numerous diseases such as neurodegenerative syndromes or cancer. In contrast to animals that possess multiple calpain types, plants contain a single 240 kDa membrane-anchored calpain DEFECTIVE KERNEL 1 (DEK1). Genetic analyses showed that DEK1 is indispensable for any organised growth in plants. In our view, DEK1 plays both sensory and effector role in translating local cues to enable and disable cellular machineries to constrain morphogenesis. The major unanswered questions are how is the DEK1 activity controlled and what are the molecular targets of its calpain.

In my presentation, I will discuss our current approaches to elucidate DEK1 mode of action. Our latest genetic analyses in Physcomitrium patens hint to the role of specific domains in post-translational regulation of DEK1. We also analyzed the gene regulatory networks of P. patens and identified the regulons that are deregulated in DEK1 mutants. We identified regulatory hierarchies in the five DEK1-controlled subnetworks that are consistent with the gene’s regulatory role in cell fate transitions. Given the existence of yet uncharacterized membrane-anchored calpains in different eukaryotic organisms, including those causing severe diseases, the model linking calpain activity with cell fate transitions represents a tool with potential use beyond plant biology.

3. 6. 2021 Ivana Fialová, 13:00, via Zoom application

Kremík v živote rastlín (Silicon in plants)

Although the silicon is not considered as an essential element for higher plants, it exerts beneficial effects on plant growth and production. Silicon alleviates both biotic and abiotic stresses, diseases, insects, drought, salinity, toxic impact of metals, nutrient imbalance, etc. It acts as a mechanical barrier and chelator and at the same time it has an influence on antioxidative defense system and plant hormone synthesis. Despite the fact that the positive effect of Si on the reduction of the toxicity of heavy metals was already proven in the 1960s, the exact mechanism of its action is not yet known.



19. 3. 2020 Munazza Kiran (University of the Punjab, Pakistan)

Dermoloma: waiting for its dawn!

Dermoloma J. E. Lange ex Herink is a poorly known genus of small, grey or brown coloured agarics of the family Tricholomataceae. European species have been mostly reported from grassland ecosystems and are considered as to be a part of a group of fungi with special conservation interest often referred to as CHEGD. Twenty two out of 34 valid species names of the genus Dermoloma are published from Europe. However, the number of accepted species is very variable in Europe, ranging from 3 to 18. The most recent general European key of Nordic mycobiota to agarics distinguishes only 3 Dermoloma spp. Our preliminary phylogenetic analysis revealed several unrelated phylogenetic lineages of Dermoloma but only few are identified based on a type sequence. There is a dire need of more precise morphological studies and of multiple loci sequencing to delimit taxonomic units and to assign names for already described species.

27. 2. 2020 Ben Avis (Indiana University Northwest, USA)

Insight in understanding diversity of fetid Russula in US Midwest

The fetid Russula group in eastern North America has been well studied historically, but recent research has focused primarily on genetics instead of morphology. The lack of morphological focus has resulted in microscopy methods to be largely unknown in United States mycology. In an attempt to introduce these methods to the mycological community in the US, I am applying standardized methods developed by Slavomír Adamčík on specimens collected in eastern North America. Through genetic analyses, we believe these specimens belong to two distinct clades at species rank. We have also found that they are both related to R. pectinatoides and R. cerolens. In order to describe these clades as new species, we must find morphological differences not only between these two clades but also between each clade in the lineage. Compared to other ectomycorrhizal fungi, fetid Russulas prefer nitrophilic habitats. Due to the recent nitrification of habitats located near agricultural areas in eastern North America, further research about the ecological function of this group is important.



2. 7. 2019, 13:00, Main Conference Room IB PSBC SAS

1. Interplay between reactive oxygen species and auxin signalling during root growth

Mgr. Loriana Demecsová

Reactive oxygen species (ROS) are versatile molecules participating in a numerous cellular processes. Whereas the biotic and abiotic stress produced ROS are well known to cause oxidative stress, leading to cell damage; there is also a role for ROS in plant cell signalling during various physiological processes. Furthermore current research suggests that the plant growth regulator auxin may be the connecting link regulating the level of ROS and directing its role in oxidative damage or signalling in plant. Therefore the aim of this seminar is to report about recent knowledge about the possible interplay between ROS and auxin signalling, be it during root growth, root gravitropism or during stress conditions.

2. Phylogenetic analyses and discovery of new species of the genus Russula (Fungi) associated with Quercus humboltii in Colombia

Michelle Vera Castellanos

Universidad del Rosario, Bogotá, Colombia; the IAPT research grant at Plant Science and Biodiversity Centre SAS

Colombia is the country with the highest diversity of different groups of organisms in the world, for example of orchids and birds. This is not true for diversity of oak trees, the country with highest diversity of oaks is Mexico and Colombia has only one oak species, Quercus humboltii, that is the only natural oak species in South America and is endemic to the country. Oak is the host tree of ectomycorrhizal fungi and specifically it is known for high species diversity of Russula species colonising its roots. Very little is known about Russula diversity in Colombia, and only 6 native species very described from the country. Majority of Russula reports from Colombia originates from oak forests and the species are often named with European or North American names. There is no a single phylogenetic study to prove broad distribution of Colombian Russula species and not a study confirming their possible genetic isolation. The Colombian oak is separated from oak forests of Panama and Latin America by a climate disjunction of Panama Isthmus that suggests possible speciation by distance within populations of Colombian Russula. However, some fungal symbionts of oak are also associated with alternative hosts allowing them wider distribution. Our study is comparing collections of Russula from oak mountainous forests of Colombia with Russula collections from North Panama associated with alternative host Oreomunnea mexicana. A significant result of the study is discovery of new species of recently described group (2019) in Colombia with identical ITS nrDNA sequences to Panama collections.

24. 5. 2019, 13:00 3rd Floor Conference Room IB PSBC SAS

Phi-like crescent cortical thickenings in roots of N. caerulescens

Mgr. Ján Kováč

Phi thickenings occur in some roots as a cortical cell wall modification, together with endodermal/exodermal Casparian bands and suberin lamellae. Although the function of the two latter mentioned modifications is known, phi thickenings remain a mystery even after decades of research. The missing consensus about the function of phi thickenings is caused by a variability in their shape, position and species in which they occur. Interestingly, the cross-section of the thickenings resembling the Greek letter phi (after which the thickenings are names) may in some species resemble more the letter “C” or a half-moon, and they occupy a substantial part of the cell wall. The aim of this seminar will be to summarize the information about these crescent thickenings in comparison with ordinary phi thickenings. Issues about structure and ultrastructure, composition, development and distribution together with possible function of crescent thickenings will be discussed.

2. Unraveling the diversity of an ectomycorrhizal genus Russula in Pakistan

M.Phil. Munazza Kiran (University of the Punjab, Pakistan)

The genus Russula is one of the largest genera of mushroom forming fungi. A large majority of species included in the genus are edible and they play a vital role in forest ecology because of their ectomycorrhizal association to some dominant tree species. Pakistan has a great variety of landscapes with diverse topography and thus a high diversity of ecosystems and habitats. The Himalaya, Hindukush and Karakoram mountain ranges host important forests in Pakistan. These have a great and varied funga associated with the mycorrhizal tree species i.e., Abies pindrow, Cedrus deodara, Juniperus macropoda, Pinus gerardiana, Picea smithiana, Pinus wallichiana. In contrast to the global knowledge of the genus, very little is known about this genus in Pakistan. Various fungal forays, over recent years, have indicated that this is an under-sampled geographic region. Recent collections and molecular phylogenetic studies have demonstrated that the Russula diversity in Pakistan is different from European continent and majority of species might be new to science.

3. 4. 2019, 13:00, Main Conference Room IB PSBC SAS

The mechanism of positional signalling in plants – understanding of the DEK1 pathway

Mgr. Viktor Demko, PhD., Prírodovedecká fakulta, Katedra fyziológie rastlín, UK

Defective Kernel 1 (DEK1), is a large membrane protein with essential functions in plant growth and development. DEK1 consists of a 23-spanning transmembrane domain, a Linker segment and C-terminal calpain protease. Loss-of-function dek1 mutants are embryo-lethal and its down-regulations cause various defects including the loss of epidermal identity and non-functional meristems. In this project we aim to unravel how is the DEK1 activated and what are its direct cellular substrates. In order to solve these problems, we combine various approaches including genetics, cell biology, and structural biology.

21. 2. 2019 štvrtok, 13:00, Main Conference Room IB PSBC SAS

1. Heavy metal and micronutrient continuum in fertilizer soil-plant system in selected areas of Eastern Dry Zone of Karnataka

Vidya Chuirappurathu Sukumaran Nair

Intensive Agriculture has led to excessive nutrient uptake from soil, fertilizer and manure sources. Soil enrichment with manures and fertilizers is an old practice, however the fertilizers are obtained from ores containing metals of various levels. The addition of fertilizer containing heavy metals over the years could lead to its accumulation in soils. Thus, there is a possibility of entry in to plant system and to the human food chain. This study on the micronutrient and heavy metal distribution in fertilizer-soil-plant system in selected areas of Eastern Dry Zone of Karnataka provides an insight in to the micronutrient and heavy metal status of the area and its content in grapes, maize and mulberry. The high organic carbon was recorded in grape growing soils compared to maize and mulberry growing soils due to high organic manure addition. Cadmium was not detected in soil samples and Cr was present in trace amounts. The total metal content in soils of study area was within maximum tolerable levels. The Cu content in leaves and fruits of grapes exceeded the limits (20 mg kg-1). This study dispels several reports that addition of DAP (Diammonium phosphate) over the years have led to accumulation of cadmium and other heavy metals.