RALFs-FERONIA requires ROPs and TORC1 complex to trigger root hair growth at low temperature in Arabidopsis thaliana
Jose M. Estevez (Argentina)1 2; Leonel Lopez (Argentina)1;
1 - Fundación Instituto Leloir and IIBBA-CONICET. Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina; 2 - Centro de Biotecnologia Vegental UNAB and ANID - Millennium Institute for Integrative Biology (iBio), Santiago, Chile;
Keywords: RALFs-FERONIA; root hair cell walls; TORC1;
Abstract Topics: Theme 9: Cell Wall Function and Signaling in plant adaptation to Biotic and Abiotic Stresses
Type of Presentation: Oral Communication

Abstract text: Root hairs (RH) serve as exemplary model systems for investigating cell size and polarity due to their ability to grow influenced by both internal and external cues. Nutrient availability and temperature are critical determinants for sustained plant development. It was previously determined that low temperature (10°C) induces a significant RH elongation response mediated by the cell surface receptor kinase FERONIA (FER) and the nutrient-sensing TOR Complex 1 (TORC1). In this scenario, the roles of RALF peptides are unclear and the molecular processes involved in their sensing and subsequent signaling pathways are not well understood. We discovered that RALFB, and to a lower extent, RALFA are both necessary for triggering RH growth at low temperature. RALFB requires TORC1 to trigger RH growth while unexpectedly RALFA is independent of this pathway. These findings reveal a molecular mechanism by which a central hub consisting of RALFB-FER-ROPs-TORC1 regulate RH elongation under conditions of low temperature while RALFA goes only through ROPs.