Drought stress perception and signalling in Arabidopsis

• Applicant: Dr. Alexander Christmann
• Subject Area: Plant Physiology
• Term: from 2006 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 27481632

Water shortage in the soil induces a response in above-ground plant tissues comprising of stomata closure for conservation of water and adjustment of metabolism to anticipated drought conditions. Stomata closure is mediated by the plant hormone abscisic acid (ABA). According to the current, widely accepted view, stomata closure of leaves in response to drying soil is triggered by a chemical signal from the root, which is either ABA itself or a shift in xylem sap pH that redirects ABA to the guard cells. However, this view is still debated and the signalling events, which relay the water stress signal from roots to the shoot, require elucidation. The project proposes to address the issue in Arabidopsis. The analysis will employ a recently developed system for non-invasive in planta imaging, which allows visualization of ABA action at the cellular level. In addition, the project employs micrografting to generate reciprocal grafts between wild type and ABA-deficient Arabidopsis. The high resolution analysis of leaf surface topography during water stress by biophysical means is proposed. Taken together, the analyses will allow us to unequivocally clarify the role of ABA in long-distance signalling of root water deficit.

• DFG Programme: Research Grants