title: Unsaturated amino acids derived from isoleucine trigger early membrane effects on plant cells.
abstract: Unsaturated amino acids (UnsAA) have been shown to affect the activity of various biological processes. However, their mode of action has been investigated poorly thus far. We show in this work that 2-amino-3-methyl-4-pentenoic acid (C2) and 2-amino-3-methyl-4-pentynoic acid (C3) structurally derived from isoleucine (Ile) exhibited a multisite action on plant cells. For one, C2 and C3 induced early modifications at the plasma membrane level, as shown by the hyperpolarization monitored by microelectrode implantation in the pulvinar cells of Mimosa pudica, indicating that these compounds are able to modify ionic fluxes. In particular, proton (H(+)) fluxes were modified, as shown by the pH rise monitored in the bathing medium of pulvinar tissues. A component of this effect may be linked to the inhibitory effect observed on the proton pumping and the vanadate-sensitive activity of the plasma membrane H(+)-ATPase monitored in plasma membrane vesicles (PMVs) purified from pulvinar tissues of M. pudica and leaf tissues of Beta vulgaris. This effect may explain, in part, the inhibitory effect of the compounds on the uptake capacity of sucrose and valine by B. vulgaris leaf tissues. In contrast, an unexpected action was observed in cell reactions, implicating ion fluxes and water movement. Indeed, the osmocontractile reactions of pulvini induced either by a mechanical shock in M. pudica or by dark and light signals in Cassia fasciculata were increased, indicating that, compared to Ile, these compounds may modify in a specific way the plasma membrane permeability to water and ions.
authors.affiliation: Laboratoire EBI (Écologie et Biologie des Interactions), UMR CNRS 7267, Équipe SEVE (Sucres, Échanges Végétaux, Environnement), Université de Poitiers, 3 rue Jacques Fort, TSA 51106, F-86073 Poitiers Cedex 9, France.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Roblin
authors.affiliation: IC2MP (Institut de Chimie des Milieux et des Matériaux de Poitiers), UMR CNRS 7285, Université de Poitiers, 4 rue Michel Brunet, TSA 51106, F-86073 Poitiers Cedex 9, France.
authors.forename: Joëlle
authors.initials: J
authors.lastname: Laduranty
authors.affiliation: Laboratoire EBI (Écologie et Biologie des Interactions), UMR CNRS 7267, Équipe SEVE (Sucres, Échanges Végétaux, Environnement), Université de Poitiers, 3 rue Jacques Fort, TSA 51106, F-86073 Poitiers Cedex 9, France.
authors.forename: Janine
authors.initials: J
authors.lastname: Bonmort
authors.affiliation: Département de Chimie, Université de Tizi-Ouzou, BP 17, RP 15000 Tizi-Ouzou, Algeria.
authors.forename: Mohand
authors.initials: M
authors.lastname: Aidene
authors.affiliation: IC2MP (Institut de Chimie des Milieux et des Matériaux de Poitiers), UMR CNRS 7285, Université de Poitiers, 4 rue Michel Brunet, TSA 51106, F-86073 Poitiers Cedex 9, France. Electronic address: jfcholle@univ-poitiers.fr.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Chollet
mesh_terms: D002462:Cell Membrane / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007532:Isoleucine / Q000737:chemistry / Q000378:metabolism*; D008564:Membrane Potentials; D031298:Mimosa / Q000166:cytology* / Q000378:metabolism*; D009995:Osmosis; D059828:Plant Cells / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000378:metabolism; D011522:Protons; D011868:Radioisotopes; D013395:Sucrose / Q000378:metabolism; D013997:Time Factors; D014633:Valine / Q000378:metabolism
chemical_list: D011522:Protons; D011868:Radioisotopes; D007532:Isoleucine; D013395:Sucrose; D006180:Proton-Translocating ATPases; D014633:Valine
keywords: H(+)-ATPase; Isoleucine analogs; Membrane potential; Nutrient transport; Osmocontractile reaction; Unsaturated amino acids