Thursday, June 27, 2019
at 2 pm amphi 208 (Coeur d’Ecole)
Characterization of AtSLAH1, a silent channel subunit involved in chloride root-to-shoot translocation
Paloma Cubero Font
BPMP, “Ion Flux Coordination and signaling in plant cells” (Influx) team
Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), Consejo Superior de Investigaciones Científicas (CSIC), Spain
Optimal growth of plants requires the synchronic supply of both chloride (Cl–) and nitrate (NO3–), which can be transported through either the same or different plasma membrane transporters. Plants accumulate Cl– to levels that are typical of the content of a macronutrient, although it is classified as a micronutrient. This enables plants to improve cell osmoregulation, water relations and growth under optimal growing conditions. Under salt stress conditions Cl– impairs NO3– nutrition apparently due to competition for membrane transport mechanisms, causing an excessive Cl– accumulation in leaves that can produce ionic toxicity. Uptake of nutrients is followed by their retention in the root or their load into the xylem for root-to-shoot transport. Xylem parenchyma and pericycle cells control the anion composition of the root-shoot xylem sap. Chloride loading into root xylem vessels is a key mechanism regulating shoot Cl– accumulation. The NO3– and Cl– conductance of xylem parenchyma cells registered by early patch clamp studies are reminiscent to electrical characteristics of anion channels from the slow-type (SLAC/SLAH) family, consisting of five members in Arabidopsis thaliana. The AtSLAH1 gene is expressed in the root xylem-pole pericycle, where it co-localizes with AtSLAH3. Both anion channels control the shoot NO3–/Cl– ratio in Arabidopsis.
Contact : Alexis De Angéli