The post-infection activity of hydrated lime against conidia of Venturia inaequalis

The post-infection activity of hydrated lime against conidia of Venturia inaequalis was evaluated using an in vitro test system based on isolated apple leaf cuticles. Experiments were conducted at 20°C and treatments were applied 24 or 48 h after inoculation. Experiments were assessed by counting living primary stromata 72 h after inoculation using fluorescence microscopy and fluorescein diacetate (FDA) as a vital stain. At the conditions of the in vitro test system hydrated lime had a post-infection activity. Suspension of 5 g l-1 applied 24 h after inoculation (16 h after infection) killed all primary stromata and stopped their further development. Treatments 48 h after inoculation reduced the number of vital primary stromata to 60% of control. Treatments with saturated solutions of hydrated lime (pH 12.45) and with KOH solutions of different pH showed that a pH higher than 12.4 was needed to be 100% effective. Suspensions of calcium carbonate (6.75 g l-1) had no effect

Die postinfektionellen Wirkungen von Kupferhydroxid und Kupfersulfat auf Konidien von Venturia inaequalis

The post-infection activity of copper hydroxide and copper sulfate against conidia of Venturia inaequalis were evaluated using an in vitro test system based on isolated apple leaf cuticles. Experiments were conducted at 20°C and treatments were applied 24 or 48 h after inoculation. Experiments were assessed by counting living primary stromata 72 h after inoculation using fluorescence microscopy and fluorescein diacetate (FDA) as a vital stain. Copper hydroxide and copper sulfate showed post-infection activity and killed primary stromata, provided the surface of the CM was kept wet. Copper hydroxide was more effective than copper sulfate and was able to kill all primary stromata 24 h after inoculation at concentrations of 116 and 231 mg l-1. Results indicate different modes of action for the highly water soluble copper sulfate and the slightly soluble copper hydroxide. Application of copper hydroxide to dry CM did not kill primary stromata. Hence, for copper hydroxide to exert post-infection activity leaves must be wet

Die postinfektionelle Wirkung von Calciumhydroxid auf Konidien von Venturia inaequalis

The post-infection activity of hydrated lime against conidia of Venturia inaequalis was evaluated using an in vitro test system based on isolated apple leaf cuticles. Experiments were conducted at 20°C and treatments were applied 24 or 48 h after inoculation. Experiments were assessed by counting living primary stromata 72 h after inoculation using fluorescence microscopy and fluorescein diacetate (FDA) as a vital stain. At the conditions of the in vitro test system hydrated lime had a post-infection activity. Suspension of 5 g l-1 applied 24 h after inoculation (16 h after infection) killed all primary stromata and stopped their further development. Treatments 48 h after inoculation reduced the number of vital primary stromata to 60% of control. Treatments with saturated solutions of hydrated lime (pH 12.45) and with KOH solutions of different pH showed that a pH higher than 12.4 was needed to be 100% effective. Suspensions of calcium carbonate (6.75 g l-1) had no effect

Suberin Goes Genomics: Use of a Short Living Plant to Investigate a Long Lasting Polymer

Suberin is a highly persistent cell wall polymer, predominantly composed of long-chain hydroxylated fatty acids. Apoplastic suberin depositions occur in internal and peripheral dermal tissues where they generate lipophilic barriers preventing uncontrolled flow of water, gases, and ions. In addition, suberization provides resistance to environmental stress conditions. Despite this physiological importance the knowledge about suberin formation has increased slowly for decades. Lately, the chemical characterization of suberin in Arabidopsis enabled the proposal of genes required for suberin biosynthesis such as β-ketoacyl-CoA synthases (KCS) for fatty acid elongation and cytochrome P450 oxygenases (CYP) for fatty acid hydroxylation. Advantaged by the Arabidopsis molecular genetic resources the in silico expression pattern of candidate genes, concerted with the tissue-specific distribution of suberin in Arabidopsis, led to the identification of suberin involved genes including KCS2, CYP86A1, and CYP86B1. The isolation of mutants with a modified suberin composition facilitated physiological studies revealing that the strong reduction in suberin in cyp86a1 mutants results in increased root water and solute permeabilities. The enhanced suberin 1 mutant, characterized by twofold increased root suberin content, has increased water-use efficiency and is affected in mineral ion uptake and transport. In this review the most recent findings on the biosynthesis and physiological importance of suberin in Arabidopsis are summarized and discussed

Encountering works by Nyerere and Freire. Exploring the connections between education for liberation and education for self-reliance in contemporary radical popular education

This conceptual paper presents an encounter of a work regarding education on self-reliance by Tanzanian educator Julius K. Nyerere (1922–1999) with a work by Brazilian educator Paolo Freire (1921–1997) on education for liberation to explore their relevance for contemporary radical popular education. To this end, the study aligns with the methodological approaches used in qualitative comparative education research. Entering into a comparative dialogue between both contributions contextualises the respective features of each contribution and allows a systematic dialogue between commonalities and differences and for conclusions to be drawn regarding radical popular education. Solidarity and sustainability serve as guiding categories in this endeavour. They point conclusively to the benefits of further theoretical encounters (with, for example, the philosophy of ubuntu), to the risks of neoliberal reinterpretations and, against this background, to the quest for nurturing contemporary approaches in radical popular education in adult education academia, research and practice under the auspices of social change and transformation. (DIPF/Orig.

An ABC transporter is involved in the silicon-induced formation of casparian bands in the exodermis of rice

Silicon (Si) promotes the formation of Casparian bands (CB) in rice and reduces radial oxygen loss (ROL). Further transcriptomic approaches revealed several candidate genes involved in the Si-induced formation of CB such as ATP binding cassette (ABC) transporter, Class III peroxidases, ligases and transferases. Investigation of these genes by means of overexpression (OE) and knockout (KO) mutants revealed the contribution of the ABC transporter (OsABCG25) to CB formation in the exodermis, which was also reflected in the expression of other OsABCG25 in the Si-promoted formation of CB genes related to the phenylpropanoid pathway, such as phenylalanine-ammonia-lyase, diacylglycerol O-acyltransferase and 4-coumarate-CoA ligase. Differential CB development in mutants and Si supply also affected the barrier function of the exodermis. OE of the ABC transporter and Si supply reduced the ROL from roots and Fe uptake. No effect on ROL and Fe uptake could be observed for the KO mutant. The presented research confirms the impact of the OsABCG25 in the Si-promoted formation of CB and its barrier functions. © 2017 Hinrichs, Fleck, Biedermann, Ngo, Schreiber and Schenk

Silicon Promotes Exodermal Casparian Band Formation in Si-Accumulating and Si-Excluding Species by Forming Phenol Complexes

We studied the effect of Silicon (Si) on Casparian band (CB) development, chemical composition of the exodermal CB and Si deposition across the root in the Si accumulators rice and maize and the Si non-accumulator onion. Plants were cultivated in nutrient solution with and without Si supply. The CB development was determined in stained root cross-sections. The outer part of the roots containing the exodermis was isolated after enzymatic treatment. The exodermal suberin was transesterified with MeOH/BF3 and the chemical composition was measured using gas chromatography-mass spectroscopy (GC-MS) and flame ionization detector (GC-FID). Laser ablation-inductively coupled plasma-mass spectroscopy (LA-ICP-MS) was used to determine the Si deposition across root cross sections. Si promoted CB formation in the roots of Si-accumulator and Si non-accumulator species. The exodermal suberin was decreased in rice and maize due to decreased amounts of aromatic suberin fractions. Si did not affect the concentration of lignin and lignin-like polymers in the outer part of rice, maize and onion roots. The highest Si depositions were found in the tissues containing CB. These data along with literature were used to suggest a mechanism how Si promotes the CB development by forming complexes with phenols.DFG/SCHR 506/12-

Modeling of Fluctuations in Dynamical Optoelectronic Device Simulations within a Maxwell-Density Matrix Langevin Approach

We present a full-wave Maxwell-density matrix simulation tool including c-number stochastic noise terms for the modeling of the spatiotemporal dynamics in active photonic devices, such as quantum cascade lasers (QCLs) and quantum dot (QD) structures. The coherent light-matter interaction in such devices plays an important role in the generation of frequency combs and other nonlinear and nonclassical optical phenomena. Since the emergence of nonlinear and nonclassical features is directly linked to the noise properties, detailed simulations of the noise characteristics are required for the development of low-noise quantum optoelectronic sources. Our semiclassical simulation framework is based on the Lindblad equation for the electron dynamics, coupled with Maxwell's equations for the optical propagation in the laser waveguide. Fluctuations arising from interactions of the optical field and quantum system with their reservoirs are treated within the quantum Langevin theory. Here, the fluctuations are included by adding stochastic c-number terms to the Maxwell-density matrix equations. The implementation in the mbsolve dynamic simulation framework is publicly available.Comment: 18 pages, 5 figure