Targeted gene knockouts reveal overlapping functions of the five Physcomitrella patens FtsZ isoforms in chloroplast division, chloroplast shaping, cell patterning, plant development, and gravity sensing.
Chloroplasts and bacterial cells divide by binary fission. The key protein in this constriction division is FtsZ, a self-assembling GTPase similar to eukaryotic tubulin. In prokaryotes, FtsZ is almost always encoded by a single gene, whereas plants harbor several nuclear-encoded FtsZ homologs. In seed plants, these proteins group in two families and all are exclusively imported into plastids. In contrast, the basal land plant Physcomitrella patens, a moss, encodes a third FtsZ family with one member. This protein is dually targeted to the plastids and to the cytosol. Here, we report on the targeted gene disruption of all ftsZ genes in P. patens. Subsequent analysis of single and double knockout mutants revealed a complex interaction of the different FtsZ isoforms not only in plastid division, but also in chloroplast shaping, cell patterning, plant development, and gravity sensing. These results support the concept of a plastoskeleton and its functional integration into the cytoskeleton, at least in the moss P. patens.
Martin
Anja
A
Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestr. 1, 79104 Freiburg, Germany.
Lang
Daniel
D
Hanke
Sebastian T
ST
Mueller
Stefanie J X
SJ
Sarnighausen
Eric
E
Vervliet-Scheebaum
Marco
M
Reski
Ralf
R
D001483:Base Sequence; D019068:Bryopsida / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D002736:Chloroplasts / Q000235:genetics / Q000378:metabolism; D017931:DNA Primers; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism; D055786:Gene Knockout Techniques / Q000379:methods*; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction; D014158:Transcription, Genetic
D017931:DNA Primers; D010940:Plant Proteins; D020558:GTP Phosphohydrolases