The Mitochondrial Type II Peroxiredoxin F Is Essential for Redox Homeostasis and Root Growth of Arabidopsis thaliana under Stress

Abstract

Peroxiredoxins (Prx) have recently moved into the focus of plant and animal research in the context of development, adaptation, and disease, as they function both in antioxidant defense by reducing a broad range of toxic peroxides and in redox signaling relating to the adjustment of cell redox and antioxidant metabolism. At-PrxII F is one of six type II Prx identified in the genome of Arabidopsis thaliana and the only Prx that is targeted to the plant mitochondrion. Therefore, it might be assumed to have functions similar to the human 2-Cys Prx (PRDX3) and type II Prx (PRDX5) and yeast 1-Cys Prx that likewise have mitochondrial localizations. This paper presents a characterization of PrxII F at the level of subcellular distribution, activity, and reductive regeneration by mitochondrial thioredoxin and glutaredoxin. By employing tDNA insertion mutants of A. thaliana lacking expression of AtprxII F (KO-AtPrxII F), it is shown that under optimal environmental conditions the absence of PrxII F is almost fully compensated for, possibly by increases in activity of mitochondrial ascorbate peroxidase and glutathione-dependent peroxidase. However, a stronger inhibition of root growth in KO-AtPrxII F seedlings as compared with wild type is observed under stress conditions induced by CdCl 2 as well as after administration of salicylhydroxamic acid, an inhibitor of cyanide-insensitive respiration. Simultaneously, major changes in the abundance of both nuclear and mitochondria-encoded transcripts were observed. These results assign a principal role to PrxII F in antioxidant defense and possibly redox signaling in plants cells.

The Arabidopsis Class II Sirtuin Is a Lysine Deacetylase and Interacts with Mitochondrial Energy Metabolism

“…The PCR product was cloned after restriction digestion with BamHI and SalI in frame into the pQE30 vector (Qiagen), which allows expression and purification of the recombinant, N-terminally 63 Histagged protein. Expression and purification of the recombinant protein were performed in BL21* cells (Invitrogen) as described in Finkemeier et al (2005). Vector constructs were verified by sequencing.…”

“…The screening for homozygous transfer DNA insertion lines was performed as described before (Finkemeier et al, 2005). Primer sequences are listed in Supplemental Table S6.…”

Isolation and Characterization of a Type II Peroxiredoxin Gene from Panax ginseng C. A. Meyer

“…A few representatives of the type II Prx have been cloned from plant sources, but knowledge on their molecular functions is limited. Mitochondrial Prx II responds to oxidative stress in Arabidopsis [14], plays a role in plant fungal pathogen interactions in poplar [23], and accumulates in response to cold and heavy metal stress in pea plants [24]. Among six identified AtPrx II genes in Arabidopsis, the expression of cytosolic AtPrx IIB and IIC is induced by oxidative stress and salt stress.…”

“…Chloroplastic Prx IIE is unregulated after bacterial exposure, and its expression decreases in response to salt stress and increases in response to bright light [6,11]. Mitochondrial AtPrx IIF expression is constitutive and is essential for root growth under stress conditions [14]. Mitochondrial AtPrx IIF expression increases in response to biotic rather than abiotic stress [23].…”

“…Six Prx II genes have been identified in Arabidopsis [6,11], one of them seems to be a pseudogene; the others are expressed in leaves. Three Prxs localized to the cytosol (AtPrx II B, C, and D), one to the chloroplast (AtPrx II E), and one to the mitochondria (AtPrx II F) [6,13,14].…”