CPSC & DynaMo Joint Seminar: Enrico Martinoia

DynaMo Semiars are a series of public seminars hosted by DynaMo Center. We are pleased to announce our next seminar speaker:

Enrico Martinoia

Institute of Plant Biology, University of Zürich

Water availability is critical for crop production. Stomata play a central role in regulating CO2 uptake and water consumption. The aperture of the stomatal pore is regulated by changes in the osmotic potentials of the guard cells that are mainly achieved by changes in ion transport across cellular membranes. We know a lot
about the solute fluxes across the plasma membrane but our knowledge about the transporters and ion channels involved in mediating solute fluxes across the vacuolar membrane is scarce. We have shown that some members of the Arabidopsis ALuminium Metal Tolerance (AtALMT) family, are tonoplast-localised anion channels. Using a combination of electrophysiology, biochemistry, and gas exchange measurements we showed that ALMT9 acts as a malate-activated chloride channel, important for stomatal opening and drought stress response. Using site-directed mutagenesis we could show that ALMTs work as multimers and that ATP strongly affect their IV curve. Recently we characterized other members of the vacuolar ALMT family and found that besides ALMTs exhibiting similar functions as AtALMT9 one member is responsible for the release of malate/chloride. In another case we could show that they form heterodimers, which changed their properties. In my talk I will give an overview on vacuolar ALMTs and present new data about their regulation.

Enrico Martinoia is Professor at University of Zurich where he is groupleader of the Department of Plant and Microbial Biology. The major topic within the group is the elucidation of the role of transporters. Another focus is the elucidation of the role of vacuolar transporters in maintaining the cytosolic homeostasis for metabolites and inorganic ions.