Organelle interactions in male gametophytes observed by electron microscopy

Abstract

In the male gametophyte of plants, organelle interactions that are temporally specific, dynamic, and unique have been observed. In the microspores and male gametophytes of Pharbitis nil, mitochondria completely surround the nucleus at a certain stage. In the male gametophyte of Arabidopsis thaliana, lipid bodies encircle the generative cell, and as maturation progresses, vacuoles surround the sperm cells, exhibiting dynamic changes. Additionally, a process known as microlipophagy, in which vacuoles contact lipid bodies, undergo membrane fusion, internalize, and degrade them, has been observed. In recent years, the existence of membrane contact sites (MCS), where organelles come into close proximity and exchange materials, has been increasingly recognized. This paper reinterprets organelle interactions observed in the male gametophyte of plants from the perspective of MCS and discusses the complexity and diversity of inter-organelle interactions.