TY - JOUR A1 - Paponov, Ivan A. A1 - Dindas , Julian A1 - Król , Elżbieta A1 - Friz, Tatyana A1 - Budnyk, Vadym A1 - Teale, William A1 - Paponov, Martina A1 - Hedrich , Rainer A1 - Palme, Klaus T1 - Auxin-Induced plasma membrane depolarization is regulated by Auxin transport and not by AUXIN BINDING PROTEIN1 JF - Frontiers in Plant Science N2 - Auxin is a molecule, which controls many aspects of plant development through both transcriptional and non-transcriptional signaling responses. AUXIN BINDING PROTEIN1 (ABP1) is a putative receptor for rapid non-transcriptional auxin-induced changes in plasma membrane depolarization and endocytosis rates. However, the mechanism of ABP1-mediated signaling is poorly understood. Here we show that membrane depolarization and endocytosis inhibition are ABP1-independent responses and that auxin-induced plasma membrane depolarization is instead dependent on the auxin influx carrier AUX1. AUX1 was itself not involved in the regulation of endocytosis. Auxin-dependent depolarization of the plasma membrane was also modulated by the auxin efflux carrier PIN2. These data establish a new connection between auxin transport and non-transcriptional auxin signaling. KW - auxin KW - ABP1 KW - plasma membrane depolarization KW - AUX1 KW - endocytosis Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-195914 SN - 1664-462X VL - 9 ER - TY - JOUR A1 - Böhm, Jennifer A1 - Scherzer, Sönke A1 - Krol, Elzbieta A1 - Kreuzer, Ines A1 - von Meyer, Katharina A1 - Lorey, Christian A1 - Mueller, Thomas D. A1 - Shabala, Lana A1 - Monte, Isabel A1 - Salano, Roberto A1 - Al-Rasheid, Khaled A. S. A1 - Rennenberg, Heinz A1 - Shabala, Sergey A1 - Neher, Erwin A1 - Hedrich, Rainer T1 - The Venus Flytrap Dionaea muscipula Counts Prey-Induced Action Potentials to Induce Sodium Uptake JF - Current Biology N2 - Carnivorous plants, such as the Venus flytrap (Dionaea muscipula), depend on an animal diet when grown in nutrient-poor soils. When an insect visits the trap and tilts the mechanosensors on the inner surface, action potentials (APs) are fired. After a moving object elicits two APs, the trap snaps shut, encaging the victim. Panicking preys repeatedly touch the trigger hairs over the subsequent hours, leading to a hermetically closed trap, which via the gland-based endocrine system is flooded by a prey-decomposing acidic enzyme cocktail. Here, we asked the question as to how many times trigger hairs have to be stimulated (e.g., now many APs are required) for the flytrap to recognize an encaged object as potential food, thus making it worthwhile activating the glands. By applying a series of trigger-hair stimulations, we found that the touch hormone jasmonic acid (JA) signaling pathway is activated after the second stimulus, while more than three APs are required to trigger an expression of genes encoding prey-degrading hydrolases, and that this expression is proportional to the number of mechanical stimulations. A decomposing animal contains a sodium load, and we have found that these sodium ions enter the capture organ via glands. We identified a flytrap sodium channel DmHKT1 as responsible for this sodium acquisition, with the number of transcripts expressed being dependent on the number of mechano-electric stimulations. Hence, the number of APs a victim triggers while trying to break out of the trap identifies the moving prey as a struggling Na+-rich animal and nutrition for the plant. KW - Venusfliegenfalle KW - Dionaea muscipula Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128054 VL - 26 IS - 3 ER - TY - JOUR A1 - Böhm, Jennifer A1 - Scherzer, Sönke A1 - Krol, Elzbieta A1 - Kreuzer, Ines A1 - von Meyer, Katharina A1 - Lorey, Christian A1 - Mueller, Thomas D. A1 - Shabala, Lana A1 - Monte, Isabel A1 - Solano, Roberto A1 - Al-Rasheid, Khaled A. S. A1 - Rennenberg, Heinz A1 - Shabala, Sergey A1 - Neher, Erwin A1 - Hedrich, Rainer T1 - The Venus flytrap Dionaea muscipula counts prey-induced action potentials to induce sodium uptake JF - Current Biology N2 - Carnivorous plants, such as the Venus flytrap (Dionaea muscipula), depend on an animal diet when grown in nutrient-poor soils. When an insect visits the trap and tilts the mechanosensors on the inner surface, action potentials (APs) are fired. After a moving object elicits two APs, the trap snaps shut, encaging the victim. Panicking preys repeatedly touch the trigger hairs over the subsequent hours, leading to a hermetically closed trap, which via the gland-based endocrine system is flooded by a prey-decomposing acidic enzyme cocktail. Here, we asked the question as to how many times trigger hairs have to be stimulated (e.g., now many APs are required) for the flytrap to recognize an encaged object as potential food, thus making it worthwhile activating the glands. By applying a series of trigger-hair stimulations, we found that the touch hormone jasmonic acid (JA) signaling pathway is activated after the second stimulus, while more than three APs are required to trigger an expression of genes encoding prey-degrading hydrolases, and that this expression is proportional to the number of mechanical stimulations. A decomposing animal contains a sodium load, and we have found that these sodium ions enter the capture organ via glands. We identified a flytrap sodium channel DmHKT1 as responsible for this sodium acquisition, with the number of transcripts expressed being dependent on the number of mechano-electric stimulations. Hence, the number of APs a victim triggers while trying to break out of the trap identifies the moving prey as a struggling Na\(^+\)-rich animal and nutrition for the plant. KW - jasmonic acid biosynthesis KW - gene expression KW - signal transduction KW - transporters KW - Arabidopsis Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-190870 VL - 26 IS - 3 ER - TY - JOUR A1 - Böhm, J. A1 - Scherzer, S. A1 - Shabala, S. A1 - Krol, E. A1 - Neher, E. A1 - Mueller, T. D. A1 - Hedrich, R. T1 - Venus flytrap HKT1-type channel provides for prey sodium uptake into carnivorous plant without conflicting with electrical excitability JF - Molecular Plant N2 - The animal diet of the carnivorous Venus flytrap, Dionaea muscipula, contains a sodium load that enters the capture organ via an HKT1-type sodium channel, expressed in special epithelia cells on the inner trap lobe surface. DmHKT1 expression and sodium uptake activity is induced upon prey contact. Here, we analyzed the HKT1 properties required for prey sodium osmolyte management of carnivorous Dionaea. Analyses were based on homology modeling, generation of model-derived point mutants, and their functional testing in Xenopus oocytes. We showed that the wild-type HKT1 and its Na\(^+\)- and K\(^+\)-permeable mutants function as ion channels rather than K\(^+\) transporters driven by proton or sodium gradients. These structural and biophysical features of a high-capacity, Na\(^+\)-selective ion channel enable Dionaea glands to manage prey-derived sodium loads without confounding the action potential-based information management of the flytrap. KW - sodium channel KW - HKT1 KW - Dionaea muscipula KW - action potential KW - glands KW - sodium uptake Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-189803 VL - 9 IS - 3 ER -