P6 - Drought Cycles

Repeated drought cycles and boron uptake in the rhizosphere


This project adresses the question whether root exudates interact with the uptake of the micronutrient boron (B), especially under conditions of drought stress.
Boron forms complexes with molecules carrying hydroxyl groups, such as sugars, sugar alcohols or phenolics. Such molecules abound in root exudates, suggesting that increased exudate production may reduce B uptake into the plant.
The first aim is therefore to collect root exudates and analyse them for B-containing complexes using 11B NMR spectroscopy. Formation of B complexes will then be correlated with B uptake studies using 10B/11B labelling and ICP-MS.
Additionally we would like to know if and how repeated drought stress alters this chemical interaction between exudates and B uptake. Drought stimulates exudation to facilitate root growth into the drying soil, but drought also induces metabolic changes in the plant, which probably affect exudate composition. How rapidly these changes are reversed during recovery from drought is unknown. The second aim is therefore to analyse metabolic changes under repeated drought cycles using metabolomic and proteomic approaches, and correlate them with B uptake.
The outcomes will provide information on the spatio-temporal pattern of “crosstalk” between stressed and non-stressed roots and plant parts, and the mechanisms leading to re-distribution of resources within the whole plant under conditions of repeated drought events.

Link to English scientific abstract

Link to German scientific abstract