Publications by authors named "Radek Jupa"

Reserves of non-structural carbohydrates (NSC) stored in living cells are essential for drought tolerance of trees. However, little is known about the phenotypic plasticity of living storage compartments (SC) and their interactions with NSC reserves under changing water availability. Here, we examined adjustments of SC and NSC reserves in stems and roots of seedlings of two temperate tree species, Acer negundo L.

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The properties of bark and xylem contribute to tree growth and survival under drought and other types of stress conditions. However, little is known about the functional coordination of the xylem and bark despite the influence of selection on both structures in response to drought. To this end, we examined relationships between proportions of bark components (i.

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Xylem transport is essential for the growth, development and survival of vascular plants. Bark wounding may increase the risk of xylem transport failure by tension-driven embolism. However, the consequences of bark wounding for xylem transport are poorly understood.

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Background And Aims: Understanding the mutual co-ordination of vegetative and reproductive growth is important in both agricultural and ecological settings. A competitive relationship between vegetative growth and fruiting is often highlighted, resulting in an apparent trade-off between structural growth and fruit production. However, our understanding of factors driving this relationship is limited.

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The use of size-controlling rootstocks is central to modern high-density fruit production systems. While biological mechanisms responsible for vigor control are not fully understood, differences in water relations and carbohydrate storage ability have been suggested as two potential factors. To better understand the processes that control growth vigor, we analyzed the trunk radial variation at seasonal and diurnal timescales and measured the midday leaf water potential (ΨMD), leaf gas exchange and concentrations of non-structural carbohydrates (NSC) in apple trees of variety 'Jonagold' grafted on two rootstocks of contrasting growth vigor (dwarfing J-TE-G vs invigorating J-TE-H).

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During soil drought (i.e. limited soil water availability to plants), woody species may adjust the structure of their vessel network to improve their resistance against future soil drought stress.

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Abscisic acid (ABA) play a crucial role in plant acclimation to heavy-metals stresses. Nevertheless, the effects of ABA on long-distance transport and its consequences for cadmium (Cd) accumulation are insufficiently understood. Here, we investigated the effects of ABA on the development of the whole-plant water transport pathway and implications for Cd uptake and transport to the shoot of Sedum alfredii.

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Ethylene is an important phytohormone for plant adaptation to heavy metal stress. However, the effects of ethylene on radial apoplastic transport of Cd remain elusive. This study investigated the role of ethylene on apoplastic barriers development and consequences for Cd uptake in Sedum alfredii.

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The transmission mode of shoot-associated endophytes in hyperaccumulators and their roles in root microbiome assembly and heavy metal accumulation remain unclear. Using 16S rRNA gene profiling, we investigated the vertical transmission of shoot-associated endophytes in relation to growth and Cd/Zn accumulation of Sedum alfredii ( Crassulaceae). Endophytes were transmitted from shoot cuttings to the rhizocompartment of new plants in both sterilized (γ-irradiated) and native soils.

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In situ remediation and assessment of sediments contaminated with both antibiotics and heavy metals remains a technological challenge. In this study, MgCl-modified biochar (BCM) was obtained at 500 °C through slow pyrolysis of Thalia dealbata and used for remediation of sediments contaminated by sulfamethoxazole (SMX) and Cd. The BCM showed greater surface area (110.

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Ion-mediated changes in hydraulic conductivity (ΔKh) represent a mechanism allowing plants to regulate the rate of xylem transport. However, the significance of ΔKh for ring-porous (RPS) and diffuse-porous tree species (DPS) remains unknown. Here, we examined ΔKh in young branches of three coexisting, temperate RPS (Fraxinus excelsior, Quercus robur, Robinia pseudoacacia) and three DPS (Acer pseudoplatanus, Carpinus betulus, Fagus sylvatica) across the whole year, and assessed the relationships of ΔKh to branch anatomy.

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Abscisic acid (ABA) is a key phytohormone underlying plant resistance to toxic metals. However, regulatory effects of ABA on apoplastic transport in roots and consequences for uptake of metal ions are poorly understood. Here, we demonstrate how ABA regulates development of apoplastic barriers in roots of two ecotypes of Sedum alfredii and assess effects on cadmium (Cd) uptake.

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Efficient water management is essential for the survival of vascular plants under drought stress. While interrelations among drought stress, plant anatomy and physiological functions have been described in woody dicots, similar research is very limited for non-palm arborescent and shrubby monocots despite their generally high drought tolerance. In this study, potted transplants of Dracaena marginata Lam.

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Although the significance of apoplasmic barriers in roots with regards to the uptake of toxic elements is generally known, the contribution of apoplasmic bypasses (ABs) to cadmium (Cd) hyperaccumulation is little understood. Here, we employed a combination of stable isotopic tracer techniques, an ABs tracer, hydraulic measurements, suberin lamellae staining, metabolic inhibitors, and antitranspirants to investigate and quantify the impact of the ABs on translocation of Cd to the xylem in roots of a hyperaccumulating (H) ecotype and a non-hyperaccumulating (NH) ecotype of Sedum alfredii. In the H ecotype, the Cd content in the xylem sap was proportional to hydrostatic pressure, which was attributed to pressure-driven flow via the ABs.

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Vessels with simple perforation plates, found in the majority of angiosperms, are considered the evolutionarily most advanced conduits, least impeding the xylem sap flow. Nevertheless, when measured, their hydraulic resistivity (R, i.e.

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The release of water from storage compartments to the transpiration stream is an important functional mechanism that provides the buffering of sudden fluctuations in water potential. The ability of tissues to release water per change in water potential, referred to as hydraulic capacitance, is assumed to be associated with the anatomy of storage tissues. However, information about how specific anatomical parameters determine capacitance is limited.

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Water relations for two remote populations of Dracaena tree species from the dragon tree group, Dracaena cinnabari Balfour f. and Dracaena draco (L.) L.

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Dye perfusion is commonly used for the identification of conductive elements important for the study of xylem development as well as precise hydraulic estimations. The tiny size of inflorescence stems, the small amount of vessels in close arrangement, and high hydraulic resistivity delimit the use of the method for quantification of the water conductivity of Arabidopsis thaliana, one of the recently most extensively used plant models. Here, we present an extensive adjustment to the method in order to reliably identify individual functional (conductive) vessels.

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