Boron foliar fertilization: impacts on absorption and subsequent translocation of foliar applied Boron

Foliar fertilization is an agricultural practice to supply plants with a specific nutrient in times of low soil availability of the nutrient or low root activity, e.g. during generative growth. The focus of this study was placed on Boron (B). Boron is an essential micronutrient for higher plants and deficiency appears in many countries on numerous crops throughout the world. B fertilization is often applied as foliar fertilizer, but the efficiency is inconsistent. The possible physiological function of B in plants is described in Chapter 1 within the general introduction. The experiments were conducted on two disparate crop species (soybean and lychee) and the impact of different parameters on foliar B absorption and subsequent translocation was studied. The first study (Chapter 2) shows the impact of plant B status on foliar B absorption and subsequent translocation in soybean. The limited absorption of foliar applied B in B deficient plants was observed in soybean and in lychee. The physiological study was developed for soybean plants pre-treated with different B root supply, ranging from deficient to B intoxicated plants. In addition, different formulations were tested in order to increase the subsequent B translocation after foliar B absorption. For this reason polyols (mannitol, sorbitol) were added to the foliar formulations, as they form stable polyol borate ester with B and these compounds enable phloem mobility in some species. Lowest absorption was observed in plants with B deficiency and B intoxication, whereas the share of subsequent B basi translocation was highest. Results correlated with measurements on stomata opening and water potential. The interruption of the transpiration stream, indicated by high water potentials in B deficient and intoxicated plants, might facilitate B phloem translocation, as it was shown in recent publications. Absorption rates were increased in treatments with polyol supplementation, probably due to a humectants effect (lowering the DRH). Subsequent translocation could not be improved by the addition of polyols. In Chapter 3 the impact of leaf side of application and adjuvant supplementation on foliar B absorption and subsequent translocation was studied on lychee and soybean. The effect of the adjuvants CaCl2 and sorbitol as humectant adjuvants and mannitol and sorbitol as B-binding adjuvants were investigated. Both plant species differed greatly in total absorption rates. Boron absorption through the abaxial leaf side was more than three-fold (soybean) or seven-fold (lychee) higher than through the adaxial side The addition of adjuvants significantly enhanced the rate of B absorption in soybean, but had no effect on B absorption in lychee. The positive results of adjuvant supplementation in soybean might be attributed to the humectants effect. Subsequent translocation could not be increased in neither of the treatments. The results on foliar B absorption via the abaxial leaf surface in both species suggest a high demand for future research, e.g. techniques to spray the abaxial leaf surface. In Chapter 4 the focus was to assess the impact of different parameters on foliar B absorption and subsequent translocation in lychee. B solutions were applied on the adaxial versus the abaxial leaf surface of mature or immature leaves. In addition, nocturnal versus diurnal application was studied. Absorption was significantly increased after application to the abaxial leaf surface. The parameters leaf age and time of application did not affect absorption. Subsequent translocation of foliar absorbed B increased significantly after foliar application of B to mature in comparison to immature leaves. Nocturnal application of B resulted in significantly enhanced basipetal B translocation. The efficacy of foliar B fertilization can be limited in lychee, especially if only the adaxial leaf surface is targeted as it commonly occurs with the spraying techniques available in many lychee orchards. The practical implications of our results clearly show that B foliar sprays should be applied nocturnally to the abaxial leaf surface. In conclusion, absorption and subsequent translocation of foliar applied B can be increased by different parameters in lychee and soybean. Plant B status and leafside of application showed a strong impact on foliar B absorption. All results are discussed in Chapter 5.Die Blattdüngung spielt eine wichtige Rolle im Pflanzenbau und findet Anwendung, wenn aufgrund von verminderter Verfügbarkeit im Boden oder während geringer Wurzelaktivität (generatives Wachstum) Versorgungsengpässe entstehen. In dieser Arbeit wurde der Mikronährstoff Bor (B) als Grundlage für die Forschungsarbeiten gewählt. Bor ist ein lebensnotwendiger Mikronährstoff für höhere Pflanzen, und Mangelerscheinungen wurden bereits in vielen Ländern an unterschiedlichsten Pflanzen beschrieben. Bor wird oft in Kombination mit Pflanzenschutzmaßnahmen über das Blatt gedüngt. Die Effektivität der B-Blattdüngung ist aber sehr variabel. Die physiologische Funktion von Bor in der Pflanze und deren Auswirkung für den Pflanzenbau wird in Chapter 1 beschrieben. Die Experimente wurden an zwei unterschiedlichen Pflanzenarten (Sojabohne, Litschi) durchgeführt und Einflussfaktoren auf die B-Blattaufnahme und nachfolgende Verlagerung getestet. Im zweiten Kapitel (Chapter 2) wurde das Thema ?Einfluss des B Versorungsgrades der Pflanzen auf die B Aufnahme und nachfolgende Verlagerung an Sojapflanzen? und der Einfluss von Additiven auf die B Verlagerung untersucht. Die Pflanzen wurden mit unterschiedlichen Borangeboten angezogen. Der Versorgungsgrad reichte von B Mangel bis B Toxizität. Zusätzlich wurden verschiedene Zusätze der Formulierung für die Blattapplikation zugesetzt, um die Verlagerung nach der Blattaufnahme zu verbessern. In Sojapflanzen ist B immobil. Die Zusätze in der Applikationslösung waren Polyole (Mannitol, Sorbitol), die stabile Verbindungen mit Bor bilden. In einigen Pflanzenarten kann B in dieser gebundenen Form im Phloem verlagert werden. Die B Blattaufnahme war stark beeinflusst vom B Versorgungsgrad der Pflanzen. B Mangel und Toxizität führten zu geringerer B Absorption über das Blatt, als bei Pflanzen mit guter bis sehr guter Versorgung. Die anschließende basipetale Verlagerung des aufgenommenen B war prozentual zur Gesamtaufnahme in den mangel- und toxischen Pflanzen am höchsten. Die Ergebnisse zeigten eine gute Korrelation mit den Wasserpotential Messungen und der Auswertungen der elektronenmikroskopischen Aufnahmen der Stomata. Eine Drosselung des Transpirationsstroms, erkennbar an den hohen Wasserpotential Werten der Pflanzen mit B Mangel und Toxizität, könnte die B Phloem Verlagerung begünstigt haben, wie kürzlich veröffentlichte Untersuchungen zeigen. Die B Blattaufnahme wurde durch die Zusätze in der Düngerlösung erhöht, mit größter Wahrscheinlichkeit ist dies auf einen ?humectant? Effekt zurück zu führen, der den flüssigen Zustand der Düngerlösung verlängert und somit das Zeitfenster zur B Aufnahme vergrößert hat. Die B Verlagerung konnte durch die Zusätze nicht verbessert werden. Im dritten Kapitel (Chapter 3) wurde der Einfluss verschiedener Zusätze in der Blattdünger Lösung auf die Aufnahme und anschließende Verlagerung an Soja- und Litschi Pflanzen untersucht. Der Beitrag der Stomata an der B Blattaufnahme wurde durch die Applikation auf die Blattober- und Blattunterseite bewertet. Beide Pflanzenarten zeigten sehr starke quantitative Unterschiede in der B Blattaufnahme. Litschi Pflanzen nahmen kaum Bor über die Blattoberseite auf (keine Stomata), wogegen über die Unterseite das 7-fache der B Menge aufgenommen wurde. Die Blätter der Soja Pflanzen absorbieten B über beide Blattseiten, wohingegen die B Aufnahme über die Blattunterseite 3-mal größer war. Soja Blätter haben mehr Stomata an der Blattunterseite. Die B Blattaufnahme wurde durch die Zusätze in der Blattdüngerlösung in Soja Pflanzen erhöht, die nachfolgende B Verlagerung wurde aber nicht beeinflusst. Litschi Pflanzen zeigten keine veränderte Aufnahme und Verlagerung mit Zusätzen in der Düngerlösung. Die Ergebnisse zeigen, dass es einen großen Forschungsbedarf bezüglich der Applikationstechniken und Zusatzstoffe gibt, um zukünftig die Blattunterseite verstärkt zu benetzen und die Blattdüngerlösungen möglichst lange in einer flüssigen Phase auf dem Blatt zu erhalten. Im dritten Abschnitt (Chapter 4) wurde der Schwerpunkt der Untersuchungen auf den Einfluss verschiedener Parameter auf die B Blattaufnahme und anschließende Verlagerung an Litschi Pflanzen gelegt. Die B Blattdünger Lösungen wurden entweder auf die Blattober- oder Blattunterseite von vollständig entwickelten oder noch wachsenden Blättern appliziert. Die Applikation erfolgte am Tag oder in der Nacht. Die B Aufnahme war signifikant erhöht nach der Applikation auf die Blattunterseite. Die Parameter Blattalter und Applikationszeitpunkt (Tag/Nacht) hatten keinen Einfluss auf die Menge an absorbieten B. Die Mobilität des absorbierten B?s wurde dagegen in vollständig entwickelten Blättern und nach Nachtapplikation erhöht. Die Applikation von Blattdüngern auf die Blattunterseite an Litschi Pflanzen scheint aus pflanzenbaulicher Sicht eine hohe Relevanz zu haben. Die Applikation bei Nacht könnte nach erfolgreicher B Aufnahme die anschließende Verteilung im Blatt begünstigen. Die Ergebnisse der drei Studien zeigen, dass die B Blattaufnahme und anschließende Verlagerung durch unterschiedliche Parameter bei beiden Pflanzenarten verbessert werden konnte. Der B-Versorgungsgrad der Pflanzen, sowie die Blattseite auf die appliziert wúrde, zeigten die größten Einflüsse auf die Blattaufnahme. Die Ergebnisse werden ausführlich in Chapter 5 diskutiert

Projectable Horava-Lifshitz gravity in a nutshell

Approximately one year ago Horava proposed a power-counting renormalizable theory of gravity which abandons local Lorentz invariance. The proposal has been received with growing interest and resulted in various different versions of Horava-Lifshitz gravity theories, involving a colourful potpourri of new terminology. In this proceedings contribution we first motivate and briefly overview the various different approaches, clarifying their differences and similarities. We then focus on a model referred to as projectable Horava-Lifshitz gravity and summarize the key results regarding its viability.Comment: 8 pages, no figures, to appear in the proceedings of First Mediterranean Conference on Classical and Quantum Gravity Conference (MCCQG), Kolymbari (Crete, Greece), September 14-18, 200

A monoclonal antibody raised against bacterially expressed MPV17 sequences shows peroxisomal, endosomal and lysosomal localisation in U2OS cells

Recessive mutations in the MPV17 gene cause mitochondrial DNA depletion syndrome, a fatal infantile genetic liver disease in humans. Loss of function in mice leads to glomerulosclerosis and sensineural deafness accompanied with mitochondrial DNA depletion. Mutations in the yeast homolog Sym1, and in the zebra fish homolog tra cause interesting, but not obviously related phenotypes, although the human gene can complement the yeast Sym1 mutation. The MPV17 protein is a hydrophobic membrane protein of 176 amino acids and unknown function. Initially localised in murine peroxisomes, it was later reported to be a mitochondrial inner membrane protein in humans and in yeast. To resolve this contradiction we tested two new mouse monoclonal antibodies directed against the human MPV17 protein in Western blots and immunohistochemistry on human U2OS cells. One of these monoclonal antibodies showed specific reactivity to a protein of 20 kD absent in MPV17 negative mouse cells. Immunofluorescence studies revealed colocalisation with peroxisomal, endosomal and lysosomal markers, but not with mitochondria. This data reveal a novel connection between a possible peroxisomal/endosomal/lysosomal function and mitochondrial DNA depletion

A monoclonal antibody raised against bacterially expressed MPV17 sequences shows peroxisomal, endosomal and lysosomal localisation in U2OS cells

Recessive mutations in the MPV17 gene cause mitochondrial DNA depletion syndrome, a fatal infantile genetic liver disease in humans. Loss of function in mice leads to glomerulosclerosis and sensineural deafness accompanied with mitochondrial DNA depletion. Mutations in the yeast homolog Sym1, and in the zebra fish homolog tra cause interesting, but not obviously related phenotypes, although the human gene can complement the yeast Sym1 mutation. The MPV17 protein is a hydrophobic membrane protein of 176 amino acids and unknown function. Initially localised in murine peroxisomes, it was later reported to be a mitochondrial inner membrane protein in humans and in yeast. To resolve this contradiction we tested two new mouse monoclonal antibodies directed against the human MPV17 protein in Western blots and immunohistochemistry on human U2OS cells. One of these monoclonal antibodies showed specific reactivity to a protein of 20 kD absent in MPV17 negative mouse cells. Immunofluorescence studies revealed colocalisation with peroxisomal, endosomal and lysosomal markers, but not with mitochondria. This data reveal a novel connection between a possible peroxisomal/endosomal/lysosomal function and mitochondrial DNA depletion

HnRNP L and L-like cooperate in multiple-exon regulation of CD45 alternative splicing

CD45 encodes a trans-membrane protein-tyrosine phosphatase expressed in diverse cells of the immune system. By combinatorial use of three variable exons 4–6, isoforms are generated that differ in their extracellular domain, thereby modulating phosphatase activity and immune response. Alternative splicing of these CD45 exons involves two heterogeneous ribonucleoproteins, hnRNP L and its cell-type specific paralog hnRNP L-like (LL). To address the complex combinatorial splicing of exons 4–6, we investigated hnRNP L/LL protein expression in human B-cells in relation to CD45 splicing patterns, applying RNA-Seq. In addition, mutational and RNA-binding analyses were carried out in HeLa cells. We conclude that hnRNP LL functions as the major CD45 splicing repressor, with two CA elements in exon 6 as its primary target. In exon 4, one element is targeted by both hnRNP L and LL. In contrast, exon 5 was never repressed on its own and only co-regulated with exons 4 and 6. Stable L/LL interaction requires CD45 RNA, specifically exons 4 and 6. We propose a novel model of combinatorial alternative splicing: HnRNP L and LL cooperate on the CD45 pre-mRNA, bridging exons 4 and 6 and looping out exon 5, thereby achieving full repression of the three variable exons

Absorption and mobility of foliar-applied boron in soybean as affected by plant boron status and application as a polyol complex

In the present study (i) the impact of plant Boron (B) status on foliar B absorption and (ii) the effect of B complexation with polyols (sorbitol or mannitol) on B absorption and translocation was investigated. Soybean (Glycine max (L.) Meer.) plants grown in nutrient solution containing 0 μM, 10 μM, 30 μM or 100 μM 11B labelled boric acid (BA) were treated with 50 mM 10B labelled BA applied to the basal parts of two leaflets of one leaf, either pure or in combination with 500 mM sorbitol or mannitol. After one week, 10B concentrations in different plant parts were determined. In B deficient leaves (0 μM 11B), 10B absorption was significantly lower than in all other treatments (9.7% of the applied dose vs. 26%–32%). The application of BA in combination with polyols increased absorption by 18–25% as compared to pure BA. The absolute amount of applied 10B moving out of the application zone was lowest in plants with 0 μM 11B supply (1.1% of the applied dose) and highest in those grown in 100 μM 11B (2.8%). The presence of sorbitol significantly decreased the share of mobile 10B in relation to the amount absorbed. The results suggest that 11B deficiency reduces the permeability of the leaf surface for BA. The addition of polyols may increase 10B absorption, but did not improve 10B distribution within the plant, which was even hindered when applied a sorbitol complex

Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign

Abstract: In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M ⊙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87’s spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded