title: Influence of arbuscular mycorrhizal colonisation on cadmium induced Medicago truncatula root isoflavonoid accumulation.
abstract: Cadmium is a serious environmental pollution threats to the planet. Its accumulation in plants affects many cellular functions, resulting in growth and development inhibition, whose mechanisms are not fully understood. However, some fungi forming arbuscular mycorrhizal symbiosis with the majority of plant species have the capacity to buffer the deleterious effect of this heavy metal. In the present work we investigated the capacity of Rhizophagus irregularis (syn. Glomus irregularis) to alleviate cadmium stress in Medicago truncatula. In spite of a reduction in all mycorrhizal parameters, plants colonized for 21 days by R. irregularis and treated by 2 mg kg⁻¹ cadmium displayed less growth inhibition in comparison to plants grown without cadmium. Cadmium strongly increased the accumulation of some isoflavonoids and their derivates: formononetin, malonylononin, medicarpin 3-O-β-(6'-malonylglucoside), medicarpin and coumestrol. Interestingly, in plants colonized by R. irregularis we noticed a strong reduction of the cadmium-induced accumulation of root isoflavonoids, a part for medicarpin and coumestrol. Moreover, transcripts of chalcone reductase, a protein that we reported previously as being down-regulated in R. irregularis-colonized M. truncatula roots, revealed a similar expression pattern with a strong increase in response to cadmium and a reduced expression in cadmium-treated mycorrhizal roots.
authors.affiliation: UMR Agroécologie INRA 1347/Agrosup/Université de Bourgogne, Pôle Interactions Plantes Microorganismes, ERL 6300 CNRS, BP 86510, 21065 Dijon Cedex, France.
authors.forename: Achref
authors.initials: A
authors.lastname: Aloui
authors.forename: Eliane
authors.initials: E
authors.lastname: Dumas-Gaudot
authors.forename: Zeina
authors.initials: Z
authors.lastname: Daher
authors.forename: Diederik
authors.initials: D
authors.lastname: van Tuinen
authors.forename: Samira
authors.initials: S
authors.lastname: Aschi-Smit
authors.forename: Dominique
authors.initials: D
authors.lastname: Morandi
mesh_terms: D000429:Alcohol Oxidoreductases / Q000235:genetics*; D018533:Biomass; D002104:Cadmium / Q000494:pharmacology*; D003375:Coumestrol / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D055137:Glomeromycota / Q000254:growth & development / Q000502:physiology*; D005960:Glucosides / Q000378:metabolism; D007529:Isoflavones / Q000378:metabolism*; D046913:Medicago truncatula / Q000187:drug effects / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D038821:Mycorrhizae / Q000254:growth & development / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D018520:Plant Shoots / Q000187:drug effects / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D036343:Pterocarpans / Q000378:metabolism; D012987:Soil; D013559:Symbiosis; D000094162:Phytoalexins
chemical_list: D000429:Alcohol Oxidoreductases; D002104:Cadmium; D003375:Coumestrol; D005960:Glucosides; D007529:Isoflavones; D010940:Plant Proteins; D036343:Pterocarpans; D012987:Soil; C007768:formononetin; C047353:medicarpin; D000094162:Phytoalexins; C093070:chalcone reductase