Low and high voltage electron microscopy of mitosis and cytokinesis in maize roots

Area of Science:

• Plant Cell Biology
• Cytoskeletal Dynamics
• Cell Division

Background:

• Understanding the dynamic behavior of cytoplasmic membranes during plant cell division is crucial for comprehending cell morphogenesis.
• The precise roles of the nuclear envelope and endoplasmic reticulum (ER) in mitosis and cytokinesis remain areas of active investigation.

Purpose of the Study:

• To investigate the structure and distribution of cytoplasmic membranes during mitosis and cytokinesis in maize root tip meristematic cells.
• To elucidate the dynamic changes in the nuclear envelope and ER throughout the cell cycle.

Main Methods:

• Utilized low and high voltage electron microscopy for detailed ultrastructural analysis.
• Employed a zinc iodide and osmium tetroxide staining technique to enhance electron opacity of membranes.
• Examined thin and thick sections to observe membrane dynamics at different resolutions.

Main Results:

• Observed nuclear envelope disassembly during prophase, integrating with the endoplasmic reticulum (ER).
• Documented the persistence of tubular (TER) and cisternal (CER) ER surrounding the spindle through metaphase and anaphase.
• Identified irregular nuclear pores persisting during mitosis, potentially serving as templates for reformation.
• Found evidence suggesting ER strands contribute to phragmoplast formation and desmotubule development.

Conclusions:

• The nuclear envelope and ER undergo significant structural reorganization during maize mitosis and cytokinesis.
• These membrane systems play integral roles in spindle organization, nuclear envelope reformation, and cell plate formation.
• The study provides insights into the formation of plasmodesmata and the desmotubule during cytokinesis.