TOR signaling in plants

N AZNAR; G CALÓ; GL SALERNO; G MARTÍNEZ-NOËL

Mar del Plata

Congreso; Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2015

SAIB

Target of rapamycin (TOR) acts as a master regulator to control cell growth andmetabolism by integrating nutrient, energy, and growth factors in all eukaryotic species. TOR kinase forms two different complex, TORC1 and TORC2, which mainly regulates the balance between anabolic and catabolic processes and cytoskeleton structure respectively. TORC1 is conserved in plants but not TORC2. To gain insights in TOR signaling pathway in photosynthetic eukaryotes we study the TOR complex in two models: Ostreococcus tauri, algae which is in the base green linage, and Arabidopsis thaliana. First, we investigated the TOR complex conservation in Ostreococcus by using different TOR inhibitors and analyzing the expression of TOR gene in diverse carbon/nitrogen availability. Regarding Arabidopsis, we evaluated the effect of sucrose, one of the main products of photosynthesis and a signal molecule, on expression of all the components of the TOR complex (TORC1). RT-PCRs experiments were performed on young seedlings of wild-type or TOR conditional mutant (tor-RNAi) treated with different concentration of the sugar. Sucrose could regulate the transcription of TORcomplex components and that regulation was almost lost in the tor mutant. In sum, our results indicate that TOR signaling is conserved in plants with specific features,especially the upstream effectors.