Mitochondrial gamma carbonic anhydrases are required for complex I assembly and plant reproductive development

verfasst von

Steffanie Fromm, Hans Peter Braun, Christoph Peterhansel

Abstract

Complex I of the mitochondrial electron transport chain (mETC) in plants contains an extra domain that is made up from proteins homologous to prokaryotic gamma-carbonic anhydrases (γCA). This domain has been suggested to participate in complex I assembly or to support transport of mitochondrial CO₂ to the chloroplast. Here, we generated mutants lacking CA1 and CA2 - two out of three CA proteins in Arabidopsis thaliana. Double mutants were characterized at the developmental and physiological levels. Furthermore, the composition and activity of the mETC were determined, and mutated CA versions were used for complementation assays. Embryo development of double mutants was strongly delayed and seed development stopped before maturation. Mutant plants could only be rescued on sucrose media, showed severe stress symptoms and never produced viable seeds. By contrast, callus cultures were only slightly affected in growth. Complex I was undetectable in the double mutants, but complex II and complex IV were upregulated concomitant with increased oxygen consumption in mitochondrial respiration. Ectopic expression of inactive CA variants was sufficient to complement the mutant phenotype. Data indicate that CA proteins are structurally required for complex I assembly and that reproductive development is dependent on the presence of complex I.

Organisationseinheit(en)

Institut für Pflanzengenetik

Typ

Artikel

Journal

New Phytologist

Band

211

Seiten

194-207

Anzahl der Seiten

14

ISSN

0028-646X

Publikationsdatum

31.05.2016

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Physiologie, Pflanzenkunde

Elektronische Version(en)

https://doi.org/10.1111/nph.13886 (Zugang: Geschlossen)