Visualization of an FtsZ ring in chloroplasts of Lilium longiflorum leaves

FtsZ is a bacterial division protein which forms a ring at the leading edge of the cell division site. To date, a hypothesis that the plant FtsZ forms the same structure in chloroplast division is proposed, but has not been d emonstrated yet. In this study, recombinant LlFtsZ (Lilium longiflorum FtsZ ) protein was produced from a previously isolated ftsZ cDNA clone [Mori and Tanaka (2000) Proto-plasma 214: 57] and used to raise polyclonal anti-LlFt sZ antibodies in rabbits. In immunoblot analysis with the total protein ext racted from L. longiflorum leaves, purified antibodies specifically recogni zed LlFtsZ whose molecular mass was approximately 43 kDa, This size corresp onded to that of the recombinant LlFtsZ protein lacking N-terminal sequence , which suggests that the full-length LlFtsZ translation product has a puta tive N-terminal signal peptide. Moreover, fluorescent and electron microsco py revealed that the anti-LlFtsZ antibodies recognized ring structures at s tromal side of the constriction point of dividing chloroplasts, Here, we sh ow direct evidence that FtsZ ring is involved in chloroplast division.