Abstract: Ceramide is a second messenger involved in many significant signal pathways of plants, such as cell growth, reduplication, differentiation, senescence and apoptosis . This work investigated the AtCER function in oxidative stress caused by H₂O₂ . The leaves of AtCER mutants cer1 , cer2 and cer3 , exhibited more severe levels of yellowing and necrotic lesions
than wild- type with H₂O₂ treatment . Further investigation by the physiological and biochemical methods, indicated that chlorophyll content of these mutants decreased more quickly than do wild type plants, and their conductivity increased significantly , and the antioxidases activity in leaves of AtCER mutants were approximately 1.5 or 3-fold higher than that inwild - type after H₂O₂ treatment . All of those results suggested that AtCER may involved in H₂O₂ -induced Oxidative stress.

Key words: Arabidopsis thaliana