Target of rapamycin signaling is tightly and differently regulated in the plant response under distinct abiotic stresses

PEREYRA, CINTIA M.; AZNAR, NÉSTOR R.; RODRIGUEZ, MARIANELA S.; SALERNO, GRACIELA L.; MARTÍNEZ-NOËL, GISELLE M. A.

PLANTA

SPRINGER

Lugar: Berlin; Año: 2019 vol. 251

0032-0935

Abstract Target of rapamycin (TOR) signaling is a central regulator of growth and development in eukaryotic organisms. However, its regulation under stress conditions has not yet been elucidated. In Arabidopsis, we show that TOR transcripts and activity in planta are inely regulated within hours after the onset of salt, osmotic, cold and oxidative stress. The expression of genes encoding the partner proteins of the TOR complex, RAPTOR3G and LST8-1, is also regulated. Besides, the data indicate that TOR activity increases at some time during the adverse condition. Interestingly, in oxidative stress, the major TOR activityincrement occurred transiently at the early phase of treatment, while in salt, osmotic and  old stress, it was around 1 day after the unfavorable condition was applied. Those results  suggest that the TOR signaling has an important role in the plant response to an exposure to stress. Moreover, basal ROS (H2O2) levels and their modiication under abiotic stresses were altered in TOR complex mutants. On the other hand, the root phenotypic analysis of the efects caused by the diverse abiotic stresses on TOR complex mutants revealed that they were diferently afected, being in some cases less sensitive, than wild-type plants to longterm unfavorable conditions. Therefore, in this work, we demonstrated that TOR signaling is  ightly regulated under abiotic stresses, at transcript and activity level, with diferent and  peciic time-course patterns according to the type of abiotic stress in Arabidopsis. Taking our results together, we propose that TOR signaling should be necessary during the plant stress response