Role of the NAD(P)H quinone oxidoreductase NQR and the cytochrome b AIR12 in controlling superoxide generation at the plasma membrane

Abstract

The quinone reductase NQR and the b-type cytochrome AIR12 of the plasma membrane are important for the control of reactive oxygen species in the apoplast. AIR12 and NQR are two proteins attached to the plant plasma membrane which may be important for generating and controlling levels of reactive oxygen species in the apoplast. AIR12 (Auxin Induced in Root culture) is a single gene of Arabidopsis that codes for a mono-heme cytochrome b. The NADPH quinone oxidoreductase NQR is a two-electron-transferring flavoenzyme that contributes to the generation of O in isolated plasma membranes. A. thaliana double knockout plants of both NQR and AIR12 generated more O and germinated faster than the single mutant affected in AIR12. To test whether NQR and AIR12 are able to interact functionally, recombinant purified proteins were added to plasma membranes isolated from soybean hypocotyls. In vitro NADH-dependent O production at the plasma membrane in the presence of NQR was reduced upon addition of AIR12. Electron donation from semi-reduced menadione to AIR12 was shown to take place. Biochemical analysis showed that purified plasma membrane from soybean hypocotyls or roots contained phylloquinone and menaquinone-4 as redox carriers. This is the first report on the occurrence of menaquinone-4 in eukaryotic photosynthetic organisms. We propose that NQR and AIR12 interact via the quinone, allowing an electron transfer from cytosolic NAD(P)H to apoplastic monodehydroascorbate and control thereby the level of reactive oxygen production and the redox state of the apoplast.

AIR12 confers cold tolerance through regulation of the CBF cold response pathway and ascorbate homeostasis

“…The DOMON domains play an important role in heme and sugar recognition reactions possibly as a participant in the electron transfer process (Iyer, Anantharaman, & Aravind, 2007). AIR12 interacts with NAD(P)H quinone oxidoreductase (NQR) via quinine, which allows an electron transfer from cytosolic NAD(P)H to apoplastic MDHA and controls ROS production and the redox status in the apoplast (Biniek et al, 2017).…”

“…It can be reduced not only by AsA but also by O 2 Á− and be oxidized by either MDHA or oxygen (Costa et al, 2015;Preger et al, 2009), while the reduced AIR12 slowly reacts with oxygen and reduces it to O 2 Á− (Costa et al, 2015). Therefore, AIR12 functions as either antioxidant in its oxidized state or a prooxidant in its reduced state depending on the redox status of the plasma membrane and the apoplast (Biniek et al, 2017 , H 2 O 2 ) and lipid peroxides in leaves (Costa et al, 2015). Given that ROS is signaling in plant responses to abiotic stress, it was hypothesized that MfAIR12 is involved in cold tolerance.…”

Evolutionary aspects of the Viridiplantae nitroreductases

“…In particular, by-products of many pollutant and herbicide are known to degrade in the mitochondria and cause the production of the highly toxic reactive superoxide. The reduction of the superoxide is catalyzsed by several families of closely related reductases localized in the mitochondria and chloroplasts, like, for example, monodehydroascorbate reductases [27] and quinone oxidoreductase [6]. Most probably, plant nitroreductases are also participating in the superoxide reduction.…”

RING Zinc Finger Proteins in Plant Abiotic Stress Tolerance

“…RING zinc finger proteins enhance harmful metal tolerance by reducing the accumulation of metals and alleviating oxidative stress. The soybean RBR type zinc finger protein GmARI1 ( Biniek et al, 2017 ) enhances plant tolerance to aluminum stress. GmARI1 is an E3 ubiquitin ligase.…”

“…Zinc finger proteins maintain a finger-like spatial configuration by binding to zinc ions through amino acids in the peptide chain, and are widely distributed in eukaryotes ( Han et al, 2020a ). RING zinc finger proteins have been identified in many plants, including Arabidopsis thaliana ( Linden et al, 2021 ; Liu et al, 2021 ; Van Nguyen et al, 2021 ), rice ( Oryza sativa ) ( Kim et al, 2020 ; Kim and Jang, 2021 ; Zhu et al, 2021 ), maize ( Zea mays ) ( Gao et al, 2012 ; Xia et al, 2012 ; Yang et al, 2018 ), pepper ( Capsicum annuum ) ( Liu et al, 2007 ; Joo et al, 2019a , 2020 ), wheat ( Triticum aestivum ) ( Agarwal and Khurana, 2018 ; Liu et al, 2018 ; Wang et al, 2020 ), potato ( Solanum tuberosum ) ( Guo et al, 2003 ; Ni et al, 2010 ; Qi et al, 2020 ), wild tomato ( Solanum pimpinellifolium ) ( Yang et al, 2016 ), wild Chinese grape ( Vitis pseudoreticulata ) ( Yu et al, 2013 ; Wang et al, 2017 ), soybean ( Glycine max ) ( Du et al, 2010 ; Biniek et al, 2017 ; Zhao et al, 2020 ), Brassica rapa ( Jung et al, 2013 ), tobacco ( Nicotiana benthamiana) ( Wu et al, 2014 ), and cassava ( Manihot esculenta Crantz) ( Dos Reis et al, 2012 ). RING zinc finger proteins have a characteristic RING zinc finger domain.…”