Studying starch content and sedimentation of amyloplast statoliths in Arabidopsis roots

Amyloplasts, organelles responsible for the synthesis and storage of starch, are of critical importance to gravitropism in higher plants. We discuss two methods that are useful for describing the histology and behavior of amyloplasts. First, because mutants with little or no plastidic starch accumulation are defective in their gravitropic response, we review a method to observe starch accumulation quickly in plant tissue. Second, we discuss a method for measuring amyloplast sedimentation in the dynamic environment of Arabidopsis root columella cells, which is thought to provide a directional cue to a reoriented plant.