Séminaire IBIP

Les séminaires ont lieu sur le Campus Montpellier SupAgro/INRA de La Gaillarde (2, place P. Viala Montpellier)

Mardi 10 Juin 2025 à 14h00 – Amphi 208 Cœur d’Ecole

Stefanie Wege

Endomembrane CHX-Type Mineral Nutrient Transporters Contribute to Plant Abiotic Stress Tolerance in Soybean and Arabidopsis

Soybean (Glycine max) is a globally important crop for food and edible oil production. Soybean plants are sensitive to salinity (NaCl), with significant yield losses under saline conditions. GmSALT3 is a dominant gene underlying a major quantitative trait locus for salt tolerance in soybean and it encodes a cation/proton exchanger (CHX). Interestingly, GmSALT3 is localised in the ER and not the plasma or vacuolar membrane, very likely excluding a direct role in ion uptake or sequestration. Similarly, we can show that Arabidopsis CHX20 is localised in the ER and contributes to stomata aperture regulation. chx20 knockout mutants show a significant increase in water loss compared to the wildtype, suggesting a role of CHX20 in drought tolerance, while Near Isogenic Lines (NILs) in soybean, which differ only in one transposon in GmSALT3, show severe differences in salt tolerance. In our project, we aim to decipher the cellular role of ER-localised CHX proteins and to connect them to mechanisms conferring abiotic stress tolerance, with a broader aim on deciphering the role of a large number of non-redundant CHX proteins in vascular plants. Through biochemical assays, we found that the large cytosolic domain of CHX proteins likely has a regulatory role connecting transporter activity to cellular energy levels and experiments using genetically encoded ion sensors as well as gene expression studies are ongoing.