Figure 5. ROS scavenging activity of transgenic plants under water-deficit stress. 15-day-old T1 seedlings were transferred to pots and allowed to establish for 20 days. Water-deficit stress was imposed by gravimetric approach and plants were maintained at 35% FC for 10 days. (A) O2.2, (B) H2O2, and (C).OH radical content were quantified by XTT, scopoletin, and 2-deoxy-D-ribose assay, respectively. Each bar value represents the mean 6 sd of triplicate experiments (student’s t test; *P,0.05 versus wild-type). doi:10.1371/journal.pone.0040397.g005 Most of the EcNAC1 overexpressing transgenic lines showed increased tolerance to osmotic and salinity stress. The growth rates of transgenic lines on simulated osmotic stress by PEG were remarkably higher than wild-type plants under short-term stress. Such a response was also observed under long-term stress experiments. Transgenic plants expressing NAC transcription factors including SNAC1 [17], ONAC063 [19], and OsNAC5 [58] have shown osmotic stress-tolerance at various stages. Overex- pression of SNAC1 not only improved drought resistance at vegetative stage in transgenic rice but also improved yield under field stress [17]. Overexpression of SNAC2 also effectively improved PEG-induced osmotic stress-tolerance in rice seedlings [18]. Arabidopsis seedlings overexpressing ONAC063 showed higher germination rates under mannitol-induced osmotic stress EcNAC1 Confers Abiotic Stress-Tolerance in Tobacco Figure 6. Lipid peroxidation in wild-type and transgenic plants under water-deficit stress. In water-deficit stressed plants MDA accumulation was measured in terms of mM/g fresh weight (FW). Each bar value represents the mean 6 sd of triplicate experiments (student’s t test; *P,0.05 versus wild-type). doi:10.1371/journal.pone.0040397.g006 [19]. Conversely, overexpression of seven other NAC genes, whose expression is induced by exogenous ABA treatment, drought or high salinity [69], did not impart salt tolerance in Arabidopsis [23], suggesting all stress-induced genes may not give tolerant phenotype. In our study, EcNAC1 was induced by salinity and we also observed superior salt tolerance of many EcNAC1 transgenics. Figure 7. Recovery response of transgenic plants subjected to water-deficit stress. At the end of water-deficit stress period plants were re-watered and observations were taken after 15-days. (A) Recovery growth and (B) Phenotype of wild-type and transgenic plants. Each bar value represents the mean 6 sd of triplicate experiments (student’s t test; *P,0.05 versus wild-type). doi:10.1371/journal.pone.0040397.g007 PLoS ONE | www.plosone.org 9 July 2012 | Volume 7 | Issue 7 | e40397