Abstract
Electron tomography has emerged as an important tool for the study of three-dimensional ultrastructure, ranging from biological nanosystems to reconstructions of whole cells. It is ideally suited for studying membrane systems.
The preprophase band (PPB) is a ring-like band of microtubules in plants that underlies the plasma membrane in G2 and prophase cells. The PPB plays an important role in the determination of the division site. Recent studies using live imaging experiments raise the question about the classical hypothesis that the Golgi derived exocytosis in the PPB involves in the marking of the division site. However, any quantitative analysis at electron microscopical level
has not yet done.
In the present study, we have investigated the mechanism of PPB membrane modifications in epidermal cells of cryofixed onion cotyledons by analyzing the endocytic and secretory structures associated with the PPB formation in electron tomograms.
