Details

Autor(en) / Beteiligte

• Fromm, Steffanie
• Braun, Hans‐Peter
• Peterhansel, Christoph

Titel

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

Ist Teil von

• The New phytologist, 2016-07, Vol.211 (1), p.194-207

Ort / Verlag

England: New Phytologist Trust

Erscheinungsjahr

2016

Link zum Volltext

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• 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.