Selective silencing of 2Cys and type‐IIB Peroxiredoxins discloses their roles in cell redox state and stress signaling

Abstract

Peroxiredoxins (Prx) catalyse the reduction of hydrogen peroxide (H2O2) and, in association with catalases and other peroxidases, may participate in signal transduction by regulating intercellular H2O2 concentration that in turn can control gene transcription and cell signaling. Using virus-induced-gene-silencing (VIGS), 2-Cys Peroxiredoxin (2CysPrx) family and type-II Peroxiredoxin B (PrxIIB) gene were silenced in Nicotiana benthamiana, to study the impact that the loss of function of each Prx would have in the antioxidant system under control (22 °C) and severe heat stress conditions (48 °C). The results showed that both Prxs, although in different organelles, influence the regeneration of ascorbate to a significant extent, but with different purposes. 2CysPrx affects abscisic acid (ABA) biosynthesis through ascorbate, while PrxIIB does it probably through the xanthophyll cycle. Moreover, 2CysPrx is key in H2O2 scavenging and in consequence in the regulation of ABA signaling downstream of reactive oxygen species and PrxIIB provides an important assistance for H2O2 peroxisome scavenges.

A 2-Cys peroxiredoxin gene from Tamarix hispida improved salt stress tolerance in plants

“…Peroxiredoxins (Prxs) are a family of non-haem peroxidases that are widely present in animals, plants and microorganisms. The biological function of these peroxidases is to regulate the balance of ROS and intracellular signal transduction through hydrogen peroxide (H 2 O 2 ), alkyl hydroperoxides, and peroxynitrite [16][17][18][19]. In plants, based on the number and position of conserved Cys residues, Prxs are grouped into four classes: 1CysPrx, 2CysPrx, type-II Prx and PrxQ.…”

Differential effects of a post-anthesis heat stress on wheat (Triticum aestivum L.) grain proteome determined by iTRAQ

“…CLPB1 is an HSP that accumulates rapidly under heat stress and has a vital regulatory effect on plant growth 35 . PrxIIB is usually found in the cytoplasm 35 and has several functions in tobacco, including regulating ascorbate regeneration, maintaining the xanthophyll cycle, and influencing H 2 O 2 production in peroxisomes 36 .…”

Interactions between 2-Cys peroxiredoxins and ascorbate in autophagosome formation during the heat stress response inSolanum lycopersicum

“…Although the functions of the chloroplast 2-CPs have been intensively studied ( Baier and Dietz, 1999 ; Broin et al , 2002 ; Awad et al , 2015 ), the precise roles of these redox proteins in heat stress responses have not been fully characterized, particularly in relation to the regulation of autophagy and other antioxidants. Using a similar VIGS approach in Nicotiana benthamiana , a recent study showed that the loss of 2-Cys peroxiredoxin family and type-II peroxiredoxin B proteins impaired the heat stress response through effects on AsA regeneration, the xanthophyll cycle, and downstream abscisic acid signalling ( Vidigal et al , 2015 ). The relationships between the 2-CPs and the ascorbate-mediated detoxification systems are particularly interesting because the chloroplast-localized 2-CPs and the tAPX have overlapping functions in H 2 O 2 removal ( Awad et al , 2015 ).…”