Trehalose signalling: understanding and exploiting an emerging small molecule carbohydrate paradigm

Sucrose and trehalose are the most widespread non-reducing disaccharides in nature. Sucrose functions as an energy reserve, building block and protective molecule in plants, and trehalose has these functions in fungi, bacteria and insects. Until recently, with very few exceptions, this division of sucrose and trehalose between the kingdoms was thought to be clear cut. However, the trehalose pathway and trehalose 6-phosphate, in particular, have been shown to play an indispensbale signalling role in plants influencing processes like photosynthesis, sugar metabolism, disease and stress resistance. The proposal will determine signalling partners of trehalose 6-phosphate and closely related non-reducing disaccharides in plants to enable chemical intervention of these important plant processes in Arabidopsis with a longer term view to crop improvement.

This proposal is driven by 1) the pressing biological question of the site of interaction of the disaccharide trehalose 6-phosphate (T6P) following its discovery as part of an indispensable signalling mechanism with significant effects on photosynthsis, sugar metabolism, disease and stress resistance in Arabidopsis; 2) the recent availability of methods in the field of glycomics, carbohydrate and protein chemistry that enable probing for the site of interaction of T6P and related compounds and the chemical intervention of its physiological function in planta. The chemical intervention approach is focused on synthesis of non-reducing glycan libraries based on the trehalose and sucrose cores. From these, small molecule glycan arrays will be made to enable the isolation of protein and nucleic acid partners. State-of-the-art protein separation and gene cloning will be used to characterise the binding partners. Construction of in planta active non-reducing mimetics and probes will enable chemical intervention in vivo.