Trehalose metabolism in nodules of Medicago truncatula under salt stress

LOPEZ M, TEJERA NA, PIECKENSTAIN FL, LLUCH, HERRERA-CERVERA JA

Boston, USA

Congreso; Plant Biology 2006; 2006

American and Canadian Societies of Plant Biologists

Trehalose is more abundant in legume nodules than in the rest of the plant. It is well known that nodular trehalose is of bacterial origin, and the different levels of trehalose found in legume nodules depend on the Rhizobium species. Part of the trehalose is excreted to the nodular cytosol, where it induces trehalase activity. Previous results by our group with Medicago truncatula demonstrated that trehalase gene expression is higher in nodules than in the rest of the plant tissues. Trehalose and trehalase could have a regulatory role of carbon metabolism in legume nodules. It has been suggested that bacteroidal trehalose modulates carbon uptake by nodules, due to its influence on trehalase activity. On the other hand, trehalose is a well-known osmoprotectant under stress conditions. The relation between trehalose and trehalase activity and osmoprotection under stress conditions is unknown. Aims of this work are to uncover the biochemical aspects of trehalose metabolism under salinity stress conditions studying the main enzymatic activities implicated in trehalose synthesis and degradation, as well as its relationship with carbon metabolism in nodules of Medicago truncatula under salinity. Results of this work indicate that the enzymatic activities responsible for trehalose synthesis and degradation are affected by salinity.