Differential expression of maize mitochondrial genes as dependent on mitochondria redox state

Abstract

We studied the effects of changes in the mitochondrial redox state, induced by respiration inhibitors, on the expression of mitochondrial genes in Zea mays. The highest levels of cox1, cox3, and cob transcripts were observed in 4 h and atp9 transcripts in 6 h after treatment with antimycin A (antA). Treatment with salicyl hydroxamic acid (SHAM) resulted in a decrease in the transcripts during the first 10 h of incubation with subsequent recovering of this gene transcript level by 24 h. Treatment with SHAM did not essentially affect the level of cox1 transcripts, whereas the levels of cox3 and cob transcripts somewhat increased during the first 4 h and remained stable thereafter. After combined treatment with antA and SHAM, the level of cox1 and cox3 transcripts dropped below the control level during the first 4 h and then increased by the end of the treatment. The content of cob transcripts increased markedly after 24 h of treatment. The rps13 transcript changed irregularly, and its changes did not coincide with changes of other transcripts studied. Thus, we demonstrated differential expression of mitochondrial genes at changes in the redox state of the mitochondrial electron transport chain (ETC). The cox1, cox3, and cob gene expression responded to these changes rather coordinately. The results obtained indicate the involvement of the ETC redox state and/or the level of reactive oxygen species in the control of mitochondrial gene expression.