Redox signal integration: from stimulus to networks and genes

Abstract

Recent research has established redox-dependent thiol modification of proteins as a major regulatory layer superimposed on most cell functional categories in plants. Modern proteomics and forward as well as reverse genetics approaches have enabled the identification of a high number of novel targets of redox regulation. Redox-controlled processes range from metabolism to transport, transcription and translation. Gene activity regulation by transcription factors such as TGA, Athb-9 and RAP2 directly or indirectly is controlled by the redox state. Knowledge on putative redox sensors such as the peroxiredoxins, on redox transmitters including thioredoxins and glutaredoxins and biochemical mechanisms of their linkage to the metabolic redox environment has emerged as the framework of a functional redox regulatory network. Its basic principle is similar in eukaryotic cells and particularly complex in the photosynthesizing chloroplast. Methods and knowledge are now at hand to develop a quantitative understanding of redox signalling and the redox regulatory network in the eukaryotic cell.

Unraveling the Tapestry of Networks Involving Reactive Oxygen Species in Plants

“…A novel function was recently assigned to the peroxiredoxin PrxIIE in detoxifying ONOO 2 , a potent oxidizing and nitrating species formed in a diffusion-limited reaction between NO and O 2 2 , suggesting a key role for peroxiredoxins in mediating the cross talk between NO and ROS Hong et al, 2008;Wilson et al, 2008). Moreover, peroxiredoxins also were reported to function as redox sensors, linking the redox signaling and ROS networks of cells (Dietz, 2008). These studies suggest integration of ROS, NO, and redox signaling in cells and provide an excellent primer for future studies that will unravel the complexity of these networks.…”

Glutathione in plants: biosynthesis and physiological role in environmental stress tolerance

“…The antioxidative property of GSH is involved in the reduction of H 2 O 2 , which in turn alters the redox state of the GSH/GSSG couple. The GSH/GSSG ratio and H 2 O 2 perform a signaling role by affecting proteins during transcription, translation, post-translational processes, and the metabolic processes conducted by the proteins (Dietz 2008;Quan et al 2008). H 2 O 2 regulates the GSH pool in maize under various abiotic stresses and imposes posttranslational regulation of c-ECS and GR transcript levels, thereby controlling GSH synthesis, the GSH/GSSG ratio, and GR activity (Kell} os et al 2008).…”

Photosynthetic Redox Imbalance Governs Leaf Sectoring in theArabidopsis thalianaVariegation Mutantsimmutans,spotty,var1, andvar2

“…More recent research in Arabidopsis suggests that redox factors on the acceptor side of PSI may be important (Dietz, 2008). These and additional signals, including the precursor of chlorophyll synthesis, magnesium protoporphyrin (Strand et al, 2003), and reactive oxygen species (ROS) generated by the PET (Meskauskiene et al, 2001;op den Camp et al, 2003), may constitute a complex network of signals involved in the retrograde pathway of communication from the chloroplast to the nucleus (Koussevitzky et al, 2007;Ferná ndez and Strand, 2008;Woodson and Chory, 2008).…”