Abstract
Physiological events such as flowering and bolting are regulated by the changes in the cellular redox state following environmental stresses. In plants, however, it remains unclear how the plant perceives the redox changes. Since protein tyrosine phosphatase (PTPase) that is easily inactivated in oxidative conditions, we considered it as a candidate factor perceiving and transducing the redox changes and investigated the functions of AtPTP1, a typical and single PTPase in Arabidopsis. A T-DNA inserted mutant of AtPTP1 grew bigger and flowered early, compared to wild-type plants. A treatment of wild-type seeds with H2O2 hastened flowering, but that of the mutant little influenced it. Considering that AtPTP1 is inactivated by H2O2, it was suggested that AtPTP1 acts downstream of H2O2 signal to negatively regulate plant growth.
