title: Validamycin A improves the response of Medicago truncatula plants to salt stress by inducing trehalose accumulation in the root nodules.
abstract: In this work, the role of trehalose as an osmoprotectant against salt stress conditions was examined in root nodules of Medicago truncatula. For this purpose, we used validamycin A, a potent trehalase inhibitor, in order to induce trehalose accumulation. Validamycin A induced an increase of trehalose concentration in root nodules of M. truncatula by inhibiting trehalase activity; no effect on trehalose concentration was observed in roots and leaves. Trehalose accumulation was accompanied by a decrease in sucrose and starch content, indicating interference with carbohydrate partitioning in the plants. Under salinity conditions, sucrose accumulation appears to be induced in M. truncatula to protect nodule functioning by the inhibition of sucrose catabolism by sucrose synthase and alkaline invertase activities. However, trehalose accumulation induced by val A in nodules improved the response to salinity by increasing plant dry weight (PDW), and no effects of validamycin A on nitrogenase activity and PDW were observed in nonsalinized plants.
authors.affiliation: Departamento de Fisiología Vegetal, Facultad de Ciencias, Universidad de Granada, Campus de Fuentenueva s/n, 18071 Granada, Spain. mlgomez@ugr.es
authors.forename: Miguel
authors.initials: M
authors.lastname: López
authors.forename: Noel A
authors.initials: NA
authors.lastname: Tejera
authors.forename: Carmen
authors.initials: C
authors.lastname: Lluch
mesh_terms: D004789:Enzyme Activation / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D007294:Inositol / Q000031:analogs & derivatives / Q000494:pharmacology; D046913:Medicago truncatula / Q000187:drug effects* / Q000378:metabolism*; D009586:Nitrogen Fixation / Q000187:drug effects; D053204:Root Nodules, Plant / Q000187:drug effects* / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological; D014198:Trehalase / Q000378:metabolism; D014199:Trehalose / Q000378:metabolism*
chemical_list: C030790:validamycin A; D012965:Sodium Chloride; D007294:Inositol; D014199:Trehalose; D014198:Trehalase