Jiří Kubásek

University of South Bohemia in České Budějovice · Faculty of Science

Symbiotic systems of photosynthetic microorganisms and fungi are widespread in terrestrial biomes and lichens are probably the most advanced and complex. Conversely, the least complex systems are "green biofilms" with a completely unexplored mycobiome. We describe here a new system intermediate between green biofilms and lichens - semilichens. Ligh...

-The plant cuticle, multifunctional hydrophobic air-to-plant boundary, vary dramatically among plant species and responds dynamically to environmental and biotic factors. These dynamics, certainly driven by cost-benefit selection, are poorly understood up to now. -13C labelling and compound-specific isotope analysis open a new avenue to study the c...

Seed-to-seedling transition represents a key developmental and metabolic switch in plants. Catabolism of seed storage reserves fuels germination and early seedling emergence until photosynthesis is established. The developmental transition is controlled by Polycomb repressive complex 2 (PRC2). However, the coordination of PRC2 activity and its cont...

Sequencing of environmental samples has great potential for biodiversity research, but its application is limited by the lack of reliable DNA barcode databases for species identifications. Such a database has been created for epiphytic lichens of Europe, allowing us to compare the results of environmental sequencing with standard taxonomic surveys....

Background and Aims The benefits and costs of amphistomy (AS) vs. hypostomy (HS) are not fully understood. Here, we quantify benefits of access of CO2 through stomata on the upper (adaxial) leaf surface, using 13C abundance in the adaxial and abaxial epicuticular wax. Additionally, a relationship between the distribution of stomata and epicuticular...

Mesophyll resistance for CO 2 diffusion ( r m ) is one of the main limitations for photosynthesis and plant growth. Breeding new varieties with lower r m requires knowledge of its distinct components. We tested new method for estimating the relative drawdowns of CO 2 concentration ( c ) across hypostomatous leaves of Fagus sylvatica . This techniqu...

In the body of multicellular organisms, macrophages play an indispensable role in maintaining tissue homeostasis by removing old, apoptotic and damaged cells. In addition, macrophages allow significant remodeling of body plans during embryonic morphogenesis, regeneration and metamorphosis. Although the huge amount of organic matter that must be rem...

Deformed wing virus (DWV) transmitted by the parasitic mite Varroa destructor is one of the most significant factors contributing to massive losses of managed colonies of western honey bee (Apis mellifera) subspecies of European origin reported worldwide in recent decades. Despite this fact, no antiviral treatment against honey bee viruses is curre...

The immune response is an energy‐demanding process that must be coordinated with systemic metabolic changes redirecting nutrients from stores to the immune system. Although this interplay is fundamental for the function of the immune system, the underlying mechanisms remain elusive. Our data show that the pro‐inflammatory polarization of Drosophila...

Alcobiosis, the symbiosis of algae and corticioid fungi, frequently occurs on bark and wood. Algae form a layer in or below fungal basidiomata reminiscent of the photobiont layer in lichens. Identities of algal and fungal partners were confirmed by DNA barcoding. Algal activity was examined using gas exchange and chlorophyll fluorescence techniques...

The plant cuticle is an important plant‐atmosphere boundary, the synthesis and maintenance of which represents a significant metabolic cost. Only limited information regarding cuticle dynamics is available. We determined the composition and dynamics of Clusia rosea cuticular waxes and matrix using ¹³CO2 labelling, compound‐specific and bulk isotope...

Some bee species use wax to build their nests. They store honey and raise their brood in cells made entirely from wax. How can the bee brood breathe and develop properly when sealed in wax cells? We compared the chemical composition and structural properties of the honey cappings and worker brood cappings of the honeybee Apis mellifera carnica, mea...

-The plant cuticle, which aided the water-to-land transition of plants, provides various services to the plant surface, and its synthesis and maintenance represent substantial metabolic costs. Nevertheless, only limited information regarding cuticle dynamics is available. -We determined the composition and dynamics of Clusia rosea cuticular waxes a...

Efficient photosynthesis requires a balance of ATP and NADPH production/consumption in chloroplasts, and the exportation of reducing equivalents from chloroplasts is important for balancing stromal ATP/NADPH ratio. Here, we showed that the overexpression of purple acid phosphatase 2 on the outer membranes of chloroplasts and mitochondria can stream...

Stomata exert control on fluxes of CO2 and water (H2O) in the majority of vascular plants and thus are pivotal for planetary fluxes of carbon and H2O. However, in mosses, the significance and possible function of the sporophytic stomata are not well understood, hindering understanding of the ancestral function and evolution of these key structures...

Efficient photosynthesis requires a balance of ATP and NADPH production/consumption in chloroplasts as the linear electron flow generates a higher NADPH/ATP ratio than that is consumed by the Calvin-Benson-Bassham cycle. Recent works suggested that ATP importation into mature chloroplasts of Arabidopsis thaliana is negligible, and therefore the exp...

The north-western Caucasus is exceptional in Europe because of its 1.3 million hectares of unmanaged ‘virgin’ forest. The Caucasus State Nature Reserve protects some 200,000 hectares, but contiguous areas are exposed to forest loss, fragmentation and degradation. Such an extensive region of virgin forest provides a unique opportunity to document di...

Within the Altai-Sayan region, we identified 103 species of Teloschistaceae from 1193 field records supported by herbarium vouchers. The recorded species belong to the subfamilies Xanthorioideae (46 species in 14 genera) and Caloplacoideae (57 species in 17 genera); Teloschistoideae is absent. We divided the 194 surveyed localities into four catego...

Cold acclimation modifies the photosynthetic machinery and enables plants to survive at sub-zero temperatures, whereas in warm habitats, many species suffer even at non-freezing temperatures. We have measured chlorophyll a fluorescence (ChlF) and CO2 assimilation to investigate the effects of cold acclimation, and of low temperatures, on a cold-sen...

Extensive sampling of lichen diversity in forest habitats in the Šumava mountains consisted of 128 plots with 824 sampled objects (single trees, snags, logs, etc.). The survey enabled assessment of regional abundance and frequency of epiphytic and epixylic lichen species. 240 species were recorded with frequencies (i.e. number of plots in which eac...

Stomata are of crucial importance for CO2 uptake and the water economy of terrestrial plants. They evolve during the early phases of leaf development according to genetically conserved information modulated in its expression by environmental conditions. Mature leaves experience the environment, e.g. light intensity, and signal to younger developing...

The study aims to assess variability in leaf water isotopic enrichment occurring in the field under natural conditions. We focused on seasonal variation and difference between sun-exposed and shaded leaves. Isotopic composition (δ¹⁸O, δ²H) of leaf water was monitored in a beach tree (Fagus sylvatica L.) growing in the forest-meadow ecotone together...

Stomata modulate the exchange of water and CO 2 between plant and atmosphere. Although stomatal density is known to affect CO 2 diffusion into the leaf and thus photosynthetic rate, the effect of stomatal density and patterning on CO 2 assimilation is not fully understood. We used wild types Col‐0 and C24 and stomatal mutants sdd1‐1 and tmm1 of Ara...

The present brief review deals with optical methods for the stable isotope analysis of biogenic elements. It consists of both the methodical and application parts and focuses on the state-of-art methods and devices and their suitability for particular analyses. Practical and financial points of view are included and compared to the current method o...

Photosynthetic kinetics in changing light intensity is considered pivotal for the survival of understorey tracheophytes; however, it is virtually unknown for bryophytes because bryophytes and tracheophytes have contrasting physio-ecological strategies. Anatomy suggests that relative rate of photosynthetic induction is faster in bryophyte gametophyt...

Stomatal density (SD) generally decreases with rising atmospheric CO2 concentration, Ca. However, SD is also affected by light, air humidity and drought, all under systemic signalling from older leaves. This makes our understanding of how Ca controls SD incomplete. This study tested the hypotheses that SD is affected by the internal CO2 concentrati...

Analysis of transmittance of young Norway spruce stand canopy for photosynthetically active radiation (PAR) was made at the study site of Bílý Kríž (the Moravian-Silesian Beskids Mts., the Czech Republic) at different sky conditions during the growing season in 2010. For the description of PAR transmittance different phenological phases of the spru...

Plants in the field are commonly exposed to fluctuating light intensity, caused by variable cloud cover, self-shading of leaves in the canopy and/or leaf movement due to turbulence. In contrast to C3 plant species, only little is known about the effects of dynamic light on photosynthesis and growth in C4 plants. Two C4 and two C3 monocot and eudico...

Some lichens that occur in mountains and arid regions have developed an unusual anatomy resembling window-leaved plants. In these lichens, algal cells occur in thick vertical stacks (algal stacks) separated by vertical channels of light-transferring fungal hyphae (fungal stacks). We present experimental evidence that this anatomy permits higher rat...

Many studies have been focused on allometry, wood-mass inventory, carbon (C) sequestration, and biomass expansion factors as the first step for the evaluation of C sinks of different plant ecosystems. To identify and quantify these terrestrial C sinks, and evaluate CO2 human-induced emissions on the other hand, information for C balance accounting...

Aboveground biomass, allometric relationships and early to late wood proportions were investigated in two even-aged monocultures of Norway spruce (Picea abies [L.] Karst) located at mountain and highland localities of the Czech Republic. However similar stand age and tree size, mountain trees comparing to them from highland showed less/tapering ste...

Caloplaca subalpina Vondrák, Šoun & Palice and C. thracopontica Vondrák & Šoun are described here as new to science. The former is a sorediate, often sterile, saxicolous species inhabiting subalpine base-rich overhanging rocks in European mountains; the latter grows on maritime cliffs of the Black Sea and is conspicuous by the lobules and pustules...

We combined measurements of short-term (during gas exchange) and long-term (from plant dry matter) carbon isotope discrimination to estimate CO(2) leakiness from bundle sheath cells in six C(4) species (three grasses and three dicots) as a function of leaf insertion level, growth temperature and short-term irradiance. The two methods for determinin...