Coalescence and directed anisotropic growth of starch granule initials in subdomains of Arabidopsis thaliana chloroplasts

Starch is the major form of energy storage in plant cells and forms discrete, semi-crystalline granules within plastids. Here the authors use electron tomography and nanoSIMS to show that Arabidopsis starch granules initiate in stromal pockets between thylakoid membranes that coalesce before growing anisotropically.