Subproject 6

Dynamics of the vacuolar proteome of Arabidopsis thaliana in response to abiotic stress factors

Dr. Jörg Reinders, Corinna Feuchtinger

Forschergruppe 1061

The plant vacuole is involved in numerous cellular functions including the accumulation and storage of metabolites, compartmentalization of toxic substances, maintenance of cell turgor, storage of the second messenger calcium and the control of ion homeostasis. In plants suffering from cold or osmotic stress, solutes such as sugars and polyols are accumulated in the vacuolar lumen. Recently, several proteins have been identified which facilitate the aforementioned transport processes across the tonoplast. Since the regulation of most of these transport proteins has not been studied in detail yet, we aim to investigate if their activity is modulated by the interaction with other proteins or posttranslational modifications such as phosphorylation upon cold stress. In a quantitative proteomic approach, we will investigate changes in the tonoplast protein pattern in plants suffering from low temperatures with particular focus on new transporters involved in cold stress signalling in Arabidopsis. The respective proteins will be further subject to further analyses in cooperation with the other groups using molecular, electrophysiological and spectroscopic methods to unravel their activation, interaction with other proteins and signalling chains in which they are involved.