EN
The Arabidopsis Ethylene-Insensitive3 (EIN3) has received attention recently and has been shown to be involved in the regulation of multitude of responses ranging from biotic stress defense and development to hormone interaction. To better understand the roles of EIN3 in plants response to salinity stress during germination and postgermination development, seeds of two EIN3 deficient mutant and a EIN3 overexpression mutant of Arabidopsis were analyzed under salinity and compared with Col-0 as control. The results showed that the ein3-1eil1-1 double mutant (lacking EIN3 and EIN3-Like1) and ein3-1 (lacking EIN3) were hypersensitive to high salinity ([150 mM NaCl), while EIN3 overexpression mutant (EIN3ox) displayed enhanced tolerance, indicating that EIN3 plays important roles during seed germination under salinity. In addition, we also found that the two EIN3 deficient mutant seedlings accumulate high levels of hydrogen peroxide (H2O2), which was thought to be an inhibitor of germination under salinity before, suggesting that EIN3 may function as a negative regulator of reactive oxygen species metabolism in germinating seeds under salinity. Taken together, our studies provide insights that EIN3 promotes seed germination under salinity, at least in part, through modulating concentration of H2O2 in germinating seeds.