title: Cadmium-induced changes in antioxidative systems and differentiation in roots of contrasted Medicago truncatula lines.
abstract: Defense pathways and stress responses induced under Cd stress were illustrated in roots of hydroponically grown Medicago truncatula seedlings. Actually, the ascorbate-glutathione and antioxidative system, secondary metabolism events including peroxidases, phenolic compounds, and lignification launching, and developmental modifications were described. Cd (100 μM) initially increased reactive oxygen species, enhanced antioxidative (total SOD, CAT, and PRX) and ascorbate-glutathione-related metabolism enzymes (APX and MDAR), except in A17 and TN1.11. In agreement with peroxidase enhancement, physiological measurement and in situ observation illustrated soluble phenolic compound accumulation under Cd treatment. However, lignification was restricted to recently created protoxylem elements established in the root tip area, usually constituting the elongation zone. Cell death was increased. In the absence of necrotic reactions, developmental changes including lignin deposition, increase in cellulose and pectin contents, intercellular meatus, and condensed and deformed hairs were noticed in Cd-treated roots.
authors.affiliation: Laboratoire de Toxicologie Végétale et Biologie Moléculaire des Microorganismes, Faculté des Sciences de Bizerte, Université de Carthage, 7021, Jarzouna, Tunisia. rahoui.sondes@yahoo.fr.|INP, UPS, Ecolab (Ecologie Fonctionnelle et Environnement), ENSAT, Université de Toulouse, 18, Chemin de Borde Rouge, 31326, Castanet-Tolosan, France. rahoui.sondes@yahoo.fr.
authors.forename: Sondès
authors.initials: S
authors.lastname: Rahoui
authors.affiliation: Fédération de Recherche «Agrobiosciences Interactions et Biodiversité», 24 Chemin de Borde Rouge-BP 42617 Auzeville, 31326, Castanet-Tolosan Cedex, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Martinez
authors.affiliation: Laboratoire de Toxicologie Végétale et Biologie Moléculaire des Microorganismes, Faculté des Sciences de Bizerte, Université de Carthage, 7021, Jarzouna, Tunisia.
authors.forename: Lamia
authors.initials: L
authors.lastname: Sakouhi
authors.affiliation: INP, UPS, Ecolab (Ecologie Fonctionnelle et Environnement), ENSAT, Université de Toulouse, 18, Chemin de Borde Rouge, 31326, Castanet-Tolosan, France.|CNRS, EcoLab, 31326, Castanet-Tolosan, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Ben
authors.affiliation: INP, UPS, Ecolab (Ecologie Fonctionnelle et Environnement), ENSAT, Université de Toulouse, 18, Chemin de Borde Rouge, 31326, Castanet-Tolosan, France.|CNRS, EcoLab, 31326, Castanet-Tolosan, France.
authors.forename: Martina
authors.initials: M
authors.lastname: Rickauer
authors.affiliation: Laboratoire de Toxicologie Végétale et Biologie Moléculaire des Microorganismes, Faculté des Sciences de Bizerte, Université de Carthage, 7021, Jarzouna, Tunisia.
authors.forename: Ezzeddine
authors.initials: E
authors.lastname: El Ferjani
authors.affiliation: INP, UPS, Ecolab (Ecologie Fonctionnelle et Environnement), ENSAT, Université de Toulouse, 18, Chemin de Borde Rouge, 31326, Castanet-Tolosan, France.|CNRS, EcoLab, 31326, Castanet-Tolosan, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Gentzbittel
authors.affiliation: Laboratoire de Toxicologie Végétale et Biologie Moléculaire des Microorganismes, Faculté des Sciences de Bizerte, Université de Carthage, 7021, Jarzouna, Tunisia.
authors.forename: Abdelilah
authors.initials: A
authors.lastname: Chaoui
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000378:metabolism; D002104:Cadmium / Q000633:toxicity*; D002454:Cell Differentiation / Q000187:drug effects*; D005978:Glutathione / Q000378:metabolism; D046913:Medicago truncatula / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D010368:Pectins / Q000378:metabolism; D010636:Phenols / Q000378:metabolism; D018517:Plant Roots / Q000033:anatomy & histology / Q000166:cytology* / Q000201:enzymology; D017382:Reactive Oxygen Species / Q000378:metabolism; D064210:Secondary Metabolism / Q000187:drug effects; D013194:Staining and Labeling
chemical_list: D000975:Antioxidants; D010636:Phenols; D017382:Reactive Oxygen Species; D002104:Cadmium; D010368:Pectins; D005978:Glutathione; D001205:Ascorbic Acid
keywords: Antioxidative systems; Cadmium; Cell death; Development changes; Medicago truncatula; Root growth