Torin 1, TOR Inhibitor Enhances Cellular Proliferation in NT-1 Tobacco Suspension Cell Cultures

Torin 1 is an ATP-competitive TOR inhibitor which inhibits the signaling of TOR and S6K kinase in mammals and plants. The objective of this research is to determine the effect of Torin 1 in a relatively simple and homogeneous plant system such as the NT-1 tobacco suspension cell cultures. Cultures of NT-1 cells were tested with 5, 50, 150 and 250 nM of Torin 1. During kinetics growth of NT-1 tobacco suspension cell cultures, 150 and 250 nM Torin 1 inhibits the early growth and later enhanced the cellular proliferation during exponential growth by means of an increased expression of E2F1 and cyclin B. Furthermore, Torin 1 stimulates the growth of NT-1 cells during log phase with small shaped cell, characteristic of tobacco suspension cell cultures with high mitotic activity.