Abstract
Protein phosphatases type 2C (PP2C) are likely to be involved in signal transduction pathways for environmental stress responses. Arabidopsis ABI1, for example, is a negative regulator of abscisic acid signaling pathway. We have found 11 PP2C-like genes (MPC1 to MPC11) from an ice plant (Mesembryanthemum crystallinum). Three independent transgenic Arabidopsis lines containing one of ice-plant PP2C gene (MPC2) under controlled by the 35S promoter were obtained. Two of them (lines 1 and 3) have a similar phenotype with a wild-type plant, but one of them (line 2) has a different phenotype that includes growth retardation and decrease of seed number. The MPC2 transcript was accumulated in the lines 1 and 3 but not in the lane 2. An endogenous transcript homologous with MPC2 decreased in the line 2. These results suggests that the phenotype of line 2 is caused by co-suppression of endogenous gene homologous with MPC2.
