Bio: Valerie Vranová is an academic researcher from Mendel University. The author has contributed to research in topics: Soil horizon & Rhizosphere. The author has an hindex of 13, co-authored 58 publications receiving 596 citations.
Papers published on a yearly basis
TL;DR: The use of continuous percolation of solid cultivation medium with adjustment of nutrient-solution strength appears to be a promising methodology for the determination of root exudation rates and qualitative composition of exuded compounds.
Abstract: The aim of this work is to review the current knowledge on the effects of plant metabolism (C3, C4, and CAM) on root exudation and on the methods of exudate collection as well as the use of such exudates for analyses, testing of microbial response, degradation of pollutants, enzymatic activities, and occurrence of allelochemicals. We examine the advantages and disadvantages of each method as related to the downstream use of the exudates. The use of continuous percolation of solid cultivation medium with adjustment of nutrient-solution strength appears to be a promising methodology for the determination of root exudation rates and qualitative composition of exuded compounds. The method mimics rhizosphere conditions, minimizing the artificial accumulation of compounds, alteration of plasma-membrane permeability, ATPase activity, and the impacts of inhibitors or stimulators of root enzymes. Of particular significance is the fact that the adjustment of strength of nutrient solution and percolation enables universal and also long-term use of the method, allowing high exudation yield by minimizing influx and maximizing efflux rates of exuded compounds at high nutrient-solution strength. Furthermore, it facilitates assessment of the effect on soil microbial populations and their ability to degrade pollutants. Enzymatic activities can be assessed when a low strength of nutrient solution is used, with percolation of the exudates directly into tested soils. Composition of root exudates, regulation of root enzymes, and plant response to nutrient deficiency can be assessed by measuring net efflux or influx rates. The impact of heavy metals and other type of mechanical, chemical, and biological stresses differs according to the type of plant metabolism. This has significant consequences on transformations in plant communities, both structurally and functionally, and impacts upon crop nutrition, with respect to global climate change, and the use of plants for phytoremediation purposes. Understanding the effects of different types of plant metabolism on root exudation with respect to genetic regulation of synthetic pathways through root enzymes and transport systems presents an important direction for future research.
TL;DR: This review attempts to appraise the literature related to non-protein amino acids, both in terms of their metabolism, plant–soil interactions and at the level of the ecosystem, where they are seen as significant drivers of structure and function.
Abstract: Non-protein amino acids are a significant store of organic nitrogen in many ecosystems, but there is a lack of knowledge relating to them. Research has indicated that they play important roles as metabolites, as allelopthic chemicals, in nutrient acquisition, in signalling and in stress response. They are also thought to be responsible for significant medical issues in both invertebrate and vertebrate animals. This review attempts to appraise the literature related to non-protein amino acids, both in terms of their metabolism, plant–soil interactions and at the level of the ecosystem, where they are seen as significant drivers of structure and function. Finally, important areas for future research are discussed.
TL;DR: In this article, a review of enzyme adsorption on soil surfaces is presented, which summarizes the key results from previous studies and provides information about how enzymes are adsorbed on the surface of the soil solid phase and how different factors affect enzymatic activity in soil.
Abstract: Abstract A majority of biochemical reactions are often catalysed by different types of enzymes. Adsorption of the enzyme is an imperative phenomenon, which protects it from physical or chemical degradation resulting in enzyme reserve in soil. This article summarizes some of the key results from previous studies and provides information about how enzymes are adsorbed on the surface of the soil solid phase and how different factors affect enzymatic activity in soil. Many studies have been done separately on the soil enzymatic activity and adsorption of enzymes on solid surfaces. However, only a few studies discuss enzyme adsorption on soil perspective; hence, we attempted to facilitate the process of enzyme adsorption specifically on soil surfaces. This review is remarkably unmatched, as we have thoroughly reviewed the relevant publications related to protein adsorption and enzymatic activity. Also, the article focuses on two important aspects, adsorption of enzymes and factors limiting the activity of adsorbed enzyme, together in one paper. The first part of this review comprehensively lays emphasis on different interactions between enzymes and the soil solid phase and the kinetics of enzyme adsorption. In the second part, we encircle various factors affecting the enzymatic activity of the adsorbed enzyme in soil.
TL;DR: Information is provided on the roles of the L- versus the D-enantiomer of pipecolic acid in plant resistance, nutrient acquisition, and decontamination of polluted soils, as well as rhizosphere ecology and medical issues.
TL;DR: Sieving through a 5 mm mesh size is suggested for all type of experiments where enhanced mineralization of low-molecular-weight organic compounds needs to be minimalized.
Abstract: Abstract The mesh size of sieves has a significant impact upon soil disturbance, affecting pore structure, fungal hyphae, proportion of fungi to bacteria, and organic matter fractions. The effects are dependent upon soil type and plant coverage. Sieving through a 2 mm mesh increases mineralization of exogenously supplied carbohydrates and phenolics compared to a 5 mm mesh and the effect is significant (p<0.05), especially in organic horizons, due to increased microbial metabolism and alteration of other soil properties. Finer mesh size particularly increases arabinose, mannose, galactose, ferulic and pthalic acid metabolism, whereas maltose mineralization is less affected. Sieving through a 5 mm mesh size is suggested for all type of experiments where enhanced mineralization of low-molecular-weight organic compounds needs to be minimalized.
01 Jan 2015
Soil enzymes: Kuprevich, V. F. & Shcherbakova, T. A.: Translated from the Russian edition (1966), published by the Indian National Scientific Documentation Centre, New Delhi 1971. 392 pp., offset printing from type script, paper cover. Obtainable from U.S. Department of Commerce, National Technical Information Service, Springfield, Va. 22151
TL;DR: The influence of spray programs on the fauna of apple orchards in Nova Scotia XIV and its relation to the natural control of the oyster shell scale Lepidosaphes ulmi L.
Abstract: B6nassy, C., 1955. R6marques sur deux Aphelinid6s: Aphelinus mytilaspidis Le Baron et Aphytis proclia Walker. Annls l~piphyt. 6: 11-17. Lord, F. T. & MacPhee, A. W., 1953. The influence of spray programs on the fauna of apple orchards in Nova Scotia II. Oyster shell scale. Can. Ent. 79: 196-209. Pickett, A. D., 1946. A progress report on long term spray programs. Rep. Nova Scotia Fruit Grow. Ass. 83 : 27-31. Pickett, A. D., 1967. The influence of spray programs on the fauna of apple orchards in Nova Scotia XIV. Can. Ent. 97: 816-821. Tothill, J. D., 1918. The predacious mite Hemisarcoptes malus Shimer and its relation to the natural control of the oyster shell scale Lepidosaphes ulmi L. Agric. Gaz. Can. 5 : 234-239.
TL;DR: The legal and regulatory status of biostimulants are described, with a focus on the EU and the US, and the drivers, opportunities and challenges of their market development are outlined.
TL;DR: There is growing scientific evidence supporting the use of biostimulants as agricultural inputs on diverse plant species, such as increased root growth, enhanced nutrient uptake, and stress tolerance.
Abstract: Plant biostimulants are diverse substances and microorganisms used to enhance plant growth. The global market for biostimulants is projected to increase 12 % per year and reach over $2,200 million by 2018. Despite the growing use of biostimulants in agriculture, many in the scientific community consider biostimulants to be lacking peer-reviewed scientific evaluation. This article describes the emerging definitions of biostimulants and reviews the literature on five categories of biostimulants: i. microbial inoculants, ii. humic acids, iii. fulvic acids, iv. protein hydrolysates and amino acids, and v. seaweed extracts. The large number of publications cited for each category of biostimulants demonstrates that there is growing scientific evidence supporting the use of biostimulants as agricultural inputs on diverse plant species. The cited literature also reveals some commonalities in plant responses to different biostimulants, such as increased root growth, enhanced nutrient uptake, and stress tolerance.
TL;DR: This review has documented the recent advancement illustrating the harmful effects of ROS, antioxidant defense system involved in ROS detoxification under different abiotic stresses, and molecular cross-talk with other important signal molecules such as reactive nitrogen, sulfur, and carbonyl species.
Abstract: Global climate change and associated adverse abiotic stress conditions, such as drought, salinity, heavy metals, waterlogging, extreme temperatures, oxygen deprivation, etc., greatly influence plant growth and development, ultimately affecting crop yield and quality, as well as agricultural sustainability in general. Plant cells produce oxygen radicals and their derivatives, so-called reactive oxygen species (ROS), during various processes associated with abiotic stress. Moreover, the generation of ROS is a fundamental process in higher plants and employs to transmit cellular signaling information in response to the changing environmental conditions. One of the most crucial consequences of abiotic stress is the disturbance of the equilibrium between the generation of ROS and antioxidant defense systems triggering the excessive accumulation of ROS and inducing oxidative stress in plants. Notably, the equilibrium between the detoxification and generation of ROS is maintained by both enzymatic and nonenzymatic antioxidant defense systems under harsh environmental stresses. Although this field of research has attracted massive interest, it largely remains unexplored, and our understanding of ROS signaling remains poorly understood. In this review, we have documented the recent advancement illustrating the harmful effects of ROS, antioxidant defense system involved in ROS detoxification under different abiotic stresses, and molecular cross-talk with other important signal molecules such as reactive nitrogen, sulfur, and carbonyl species. In addition, state-of-the-art molecular approaches of ROS-mediated improvement in plant antioxidant defense during the acclimation process against abiotic stresses have also been discussed.