AtCOX10, a protein required for heme a synthesis during COX assembly, is involved in plant embryogenesis and senescence.

MANSILLA, NATANAEL; GARCÍA, LUCILA; GONZALEZ, DANIEL H.; WELCHEN, ELINA

Congreso; L Reunión SAIB; 2014

Cytochrome c oxidase biogenesis requires more than 20 accessory proteins implicated, among other processes, in copper and heme a insertion. COX10 catalyzes the conversion of heme b to heme o, and is essential for the insertion the heme a in the COX1 subunit in yeast. By complementation analysis of yeast ∆cox10 mutant, we observed that the Arabidopsis homologous protein AtCOX10 was able to restore growth on non-fermentable carbon. We have also studied Arabidopsis mutant plants with a T-DNA insertion in the coding region of the AtCOX10 gene. Segregation analysis demonstrated that was no possible to obtain knockout plants, suggesting that AtCOX10 is essential during plant embryogenesis. In addition, low levels of AtCOX10 could impact directly on the onset and progression in both natural and induced senescence processes. Heterozygous mutant plants reached senescence time before than WT, showing less chlorophyll content, lower levels of Fv/Fm parameter and higher transcript levels for Senescence Associated Genes (SAGs) than Wt plants. Our results suggest the importance of Complex IV and AtCOX10 during plant senescence is probably due to their main role in ATP production and it relation with nutrient remobilization and energy supply for all other cellular processes.