TOR Complex and Arabidopsis-pathogen Interaction

G. MARTÍNEZ-NOËL; V.F. CONSOLO; N. AZNAR; G.L. SALERNO

Buenos Aires

Congreso; XXXIX Reunión Anual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular; 2013

The TOR (Target Of Rapamycin) pathway is a major controller of growth-related processes in eukaryotes. The plant TOR complex comprises the TOR kinase, and the proteins Raptor and LST8. Under favorable environmental conditions, the TOR pathway promotes growth and limits catabolic processes. There must exist a balance between growth and disease resistance, thus TOR signaling should be regulated in a biotic stress situation. We studied plant-pathogen interactions in the model plant Arabidopsis thaliana, using mutants in different TOR complex proteins. Plants of 25-d were sprayed with a fungus solution and evaluated for 14-d. We assayed Fusarium graminearum and Botrytis cinerea strains isolated from Prov Bs As, two important pathogens that cause major agronomic crop losses. We show that the mutant Raptor is tolerant to Fusarium but susceptible to Botrytis. Fusarium-inoculated Raptor plants do not present fungus growth or plant cell death. On the other hand the LST8 mutant resulted susceptible to the infection with both fungi. Infection of LST8 mutant with Botrytis was slower than that of wt plants. Gene expression was analyzed in leaves up to 3-d of treatment. Although additional experiments are needed, our results indicate that the TOR signaling pathway could be involved in biotic stress response.