Abstract
Mimosa pudica closes its leaves and bends its petioles in response to various stimuli. Biochemical analysis suggested that actin is implicated in the bending event of Mimosa pudica. We hypothesized that actin-binding proteins are key factors to control the actin re-organization during bending events. Consequently, annexin was isolated with F-actin chromatography in a calcium-dependent manner. Mimosa annexin has a phospholipid binding ability in the presence of calcium as with other animal and plant annexins. Furthermore, we confirmed that amount of annexin in pulvinus was increased by abcisic acid (ABA)- and cold-treatment. However, direct interaction of annexin to actin in vivo was not evident by distribution analysis. These data suggested that annexin has a role in metabolic or developmental events rather than in re-organization of actin cytoskeleton, which occurs along with bending events.
