The cytochrome c oxidase biogenesis factor AtCOX17 is part of a mitochondrial signaling pathway involved in the response of plants to stress

GARCÍA L,; WELCHEN E,; GEY U,; ARCE A,; STEINEBRUNNER I,; GONZALEZ DH.

Plant, Cell & Environment

Blackwell Publishing Ltd

Año: 2015

1365-3040

40 ABSTRACT41 COX17 is a small soluble protein from the mitochondrial intermembrane space that42 participates in the transfer of copper for cytochrome c oxidase (COX) assembly.43 Arabidopsis thaliana contains two AtCOX17 genes, AtCOX17-1 and AtCOX17-2. We44 show here that the expression of both genes is induced by several stress conditions,45 abscisic acid, and mutations in the transcription factor ABI4. Silencing of AtCOX17-146 in a cox17-2 mutant background generates plants with smaller rosettes and decreased47 expression of genes involved in the response of plants to stress, among them those48 encoding transcription factors WRKY53, CBF2, ERF1 and ANAC019. These plants49 also show reduced expression of the stress-responsive genes AOX1a, AOX1d and NDB2,50 which encode components of the alternative respiration pathway. Silencing of51 individual AtCOX17 genes does not affect plant development but causes a decrease in52 the response of genes to salt and high-light stress. On the other hand, overexpression of53 AtCOX17 renders plants more tolerant to salt stress. The fact that AtCOX17 expression54 levels affect the response of genes involved in stress responses suggests that AtCOX1755 participates in signal transduction pathways involved in plant adaptation to adverse56 conditions. The results highlight the role of mitochondrial proteins as sensors of stress57 conditions that impact nuclear gene expression.