Abstract
Chloroplasts are endosymbiotic resultants of an ancient photosynthetic prokaryote, related to modern cyanobacteria. The modern chloroplasts utilise the inherent prokaryotic and the acquired eukaryotic systems for their development and functions in cells. Chloroplast division, an essential cellular process in plants, also represents a "hybrid" that involves the co-ordinated action of the prokaryotic division proteins and the eukaryotic membrane fission proteins.
Recent studies have revealed that the conserved system is essential for the initiation of chloroplast division and the products of Min that determine the division site in prokaryotic cells also participate in chloroplast division. Here, we investigated the role of AtMinE1, a nucleus-encoded MinE orthologue, in the model plant, Arabidopsis thaliana. We constructed transgenic Arabidopsis plants which overexpress or downexpress AtMinE1. Detailed microscopic characterisations of chloroplasts in the transgenic plants revealed that AtMinE1 is an indispensable plastid division factor and is involved in division site placement of chloroplasts.
