TY - JOUR ID - 2141 TI - Identification of hypoglycin A binding adsorbents as potential preventive measures in co-grazers of atypical myopathy affected horses JO - Equine Vet J PY - 2018 SP - 220-227 AU - Krägeloh, T. AU - Cavalleri, J. M. V. AU - Ziegler, J. AU - Sander, J. AU - Terhardt, M. AU - Breves, G. AU - Cehak, A. VL - 50 UR - https://dx.doi.org/10.1111/evj.12723 DO - 10.1111/evj.12723 AB - BackgroundIntestinal absorption of hypoglycin A (HGA) and its metabolism are considered major prerequisites for atypical myopathy (AM). The increasing incidence and the high mortality rate of AM urgently necessitate new therapeutic and/or preventative approaches.ObjectivesTo identify a substance for oral administration capable of binding HGA in the intestinal lumen and effectively reducing the intestinal absorption of the toxin.Study designExperimental in vitro study.MethodsSubstances commonly used in equine practice (activated charcoal composition, di‐tri‐octahedral smectite, mineral oil and activated charcoal) were tested for their binding capacity for HGA using an in vitro incubation method. The substance most effective in binding HGA was subsequently tested for its potential to reduce intestinal HGA absorption. Jejunal tissues of 6 horses were incubated in Ussing chambers to determine mucosal uptake, tissue accumulation, and serosal release of HGA in the presence and absence of the target substance. Potential intestinal metabolism in methylenecyclopropyl acetic acid (MCPA)‐conjugates was investigated by analysing their concentrations in samples from the Ussing chambers.ResultsActivated charcoal composition and activated charcoal were identified as potent HGA binding substances with dose and pH dependent binding capacity. There was no evidence of intestinal HGA metabolism.Main limitationsBinding capacity of adsorbents was tested in vitro using aqueous solutions, and in vivo factors such as transit time and composition of intestinal content, may affect adsorption capacity after oral administration.ConclusionsFor the first time, this study identifies substances capable of reducing HGA intestinal absorption. This might have major implications as a preventive measure in cograzers of AM affected horses but also in horses at an early stage of intoxication. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1788 TI - Iron-Dependent Callose Deposition Adjusts Root Meristem Maintenance to Phosphate Availability JO - Devel Cell PY - 2015 SP - 216–230 AU - Müller, J. AU - Toev, T. AU - Heisters, M. AU - Teller, J. AU - Moore, K. L. AU - Hause, G. AU - Dinesh, D. C. AU - Bürstenbinder, K. AU - Abel, S. VL - 33 UR - http://www.sciencedirect.com/science/article/pii/S1534580715001094 DO - 10.1016/j.devcel.2015.02.007 AB - Plant root development is informed by numerous edaphic cues. Phosphate (Pi) availability impacts the root system architecture by adjusting meristem activity. However, the sensory mechanisms monitoring external Pi status are elusive. Two functionally interacting Arabidopsis genes, LPR1 (ferroxidase) and PDR2 (P5-type ATPase), are key players in root Pi sensing, which is modified by iron (Fe) availability. We show that the LPR1-PDR2 module facilitates, upon Pi limitation, cell-specific apoplastic Fe and callose deposition in the meristem and elongation zone of primary roots. Expression of cell-wall-targeted LPR1 determines the sites of Fe accumulation as well as callose production, which interferes with symplastic communication in the stem cell niche, as demonstrated by impaired SHORT-ROOT movement. Antagonistic interactions of Pi and Fe availability control primary root growth via meristem-specific callose formation, likely triggered by LPR1-dependent redox signaling. Our results link callose-regulated cell-to-cell signaling in root meristems to the perception of an abiotic cue A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 1304 TI - Phosphate sensing in root development JO - Curr Opin Plant Biol PY - 2011 SP - 303-309 AU - Abel, S. VL - 14 UR - https://dx.doi.org/10.1016/j.pbi.2011.04.007 DO - 10.1016/j.pbi.2011.04.007 AB - Phosphate (Pi) and its anhydrides constitute major nodes in metabolism. Thus, plant performance depends directly on Pi nutrition. Inadequate Pi availability in the rhizosphere is a common challenge to plants, which activate metabolic and developmental responses to maximize Pi usage and acquisition. The sensory mechanisms that monitor environmental Pi and transmit the nutritional signal to adjust root development have increasingly come into focus. Recent transcriptomic analyses and genetic approaches have highlighted complex antagonistic interactions between external Pi and Fe bioavailability and have implicated the stem cell niche as a target of Pi sensing to regulate root meristem activity. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 854 TI - Auxin signaling JO - Curr Opin Plant Biol PY - 2006 SP - 448-453 AU - Quint, M. AU - Gray, W.M. VL - 9 UR - DO - 10.1016/j.pbi.2006.07.006 AB - Auxin regulates a host of plant developmental and physiological processes, including embryogenesis, vascular differentiation, organogenesis, tropic growth, and root and shoot architecture. Genetic and biochemical studies carried out over the past decade have revealed that much of this regulation involves the SCFTIR1/AFB-mediated proteolysis of the Aux/IAA family of transcriptional regulators. With the recent finding that the TRANSPORT INHIBITOR RESPONSE1 (TIR1)/AUXIN SIGNALING F-BOX (AFB) proteins also function as auxin receptors, a potentially complete, and surprisingly simple, signaling pathway from perception to transcriptional response is now before us. However, understanding how this seemingly simple pathway controls the myriad of specific auxin responses remains a daunting challenge, and compelling evidence exists for SCFTIR1/AFB-independent auxin signaling pathways. A2 - C1 - Molecular Signal Processing ER - TY - JOUR ID - 388 TI - Induction of a new lipoxygenase form in cucumber leaves by salicylic acid or 2,6-dichloroisonicotinic acid JO - Bot. Acta PY - 1997 SP - 101-108 AU - Feussner, I. AU - Fritz, I.G. AU - Hause, B. AU - Ullrich, W.R. AU - Wasternack, C. VL - 110 UR - http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1438-8677/issues DO - 10.1111/j.1438-8677.1997.tb00616.x AB - Changes in lipoxygenase (LOX) protein pattern and/or activity were investigated in relation to acquired resistance of cucumber (Cucumis sativus L.) leaves against two powdery mildews, Sphaerotheca fuliginea (Schlecht) Salmon and Erysiphe cichoracearum DC et Merat. Acquired resistance was established by spraying leaves with salicylic acid (SA) or 2,6-dichloroisonicotinic acid (INA) and estimated in whole plants by infested leaf area compared to control plants. SA was more effective than INA. According to Western blots, untreated cucumber leaves contained a 97 kDa LOX form, which remained unchanged for up to 48 h after pathogen inoculation. Upon treatment with SA alone for 24 h or with INA plus pathogen, an additional 95 kDa LOX form appeared which had an isoelectric point in the alkaline range. For the induction of this form, a threshold concentration of 1 mM SA was required, higher SA concentrations did not change LOX-95 expression which remained similar between 24 h and 96 h but further increased upon mildew inoculation. Phloem exudates contained only the LOX-97 form, in intercellular washing fluid no LOX was detected. dichloroisonicotinic localization revealed LOX protein in the cytosol of the mesophyll cells without differences between the forms. A2 - C1 - Molecular Signal Processing; Cell and Metabolic Biology ER -