High level of reduced glutathione contributes to detoxification of lipid peroxide‐derived reactive carbonyl species in transgenic Arabidopsis overexpressing glutathione reductase under aluminum stress

Abstract

Lipid peroxide-derived reactive carbonyl species (RCS), generated downstream of reactive oxygen species (ROS), are critical damage-inducing species in plant aluminum (Al) toxicity. In mammals, RCS are scavenged primarily by glutathione (reduced form of glutathione, GSH), but in plant Al stress, contribution of GSH to RCS detoxification has not been evaluated. In this study, Arabidopsis plants overexpressing the gene AtGR1 (accession code At3g24170), encoding glutathione reductase (GR), were generated, and their performance under Al stress was examined. These transgenic plants (GR-OE plants) showed higher GSH levels and GSH/GSSG (oxidized form of GSH) ratio, and an improved Al tolerance as they suffered less inhibition of root growth than wild-type under Al stress. Exogenous application of 4-hydroxy-2-nonenal, an RCS responsible for Al toxicity in roots, markedly inhibited root growth in wild-type plants. GR-OE plants suffered significantly smaller inhibition, indicating that the enhanced GSH level increased the capacity of RCS detoxification. The generation of H O due to Al stress in GR-OE plants was lower by 26% than in wild-type. Levels of various RCS, such as malondialdehyde, butyraldehyde, phenylacetaldehyde, (E)-2-heptenal and n-octanal, were suppressed by more than 50%. These results indicate that high levels of GSH and GSH/GSSG ratio by GR overexpression contributed to the suppression of not only ROS, but also RCS. Thus, the maintenance of GSH level by overexpressing GR reinforces dual detoxification functions in plants and is an efficient approach to enhance Al tolerance.

Evidence of a significant role of glutathione reductase in the sulfur assimilation pathway

“…Despite metabolic and gene expression changes, the morphological phenotype of the transgenic tobacco and Arabidopsis plants, as well as of the mutants, did not undergo significant changes under normal conditions (Figures S5–S7). This is in accordance with other studies showing that transgenic Arabidopsis plants overexpressing GR1 and the gr1 mutant have a similar phenotype to WT (Marty et al , ; Mhamdi et al , ; Yin et al , ). In addition, a significant reduction in the endogenous GR expression level in tobacco, Arabidopsis and rice did not lead to changes in the phenotype (Ding et al , , ; Mhamdi et al , ; Wu et al , ).…”

Butylated Hydroxytoluene (BHT) Inhibits PIN1 Exocytosis From BFA Compartments in Arabidopsis Roots

“…A different pattern of activity for PIN1 and PIN2 trafficking was also indicated by our experiment with the reduced form of glutathione (GSH) (Figure 4) and the reducing agent DTT (Figure 6), both of which are known to reduce ROS concentration in plants (Kovacik et al, 2009;Yin et al, 2017). These results indicated that the specific effect of BHT on PIN trafficking cannot be explained exclusively by the modulation of ROS concentration.…”

Comparative volatile compounds and primary metabolites profiling of pitaya fruit peel after ozone treatment

“…C). It has been reported previously that 2‐heptenal and octanal play a vital role in responding to aluminium stress by enhancing ROS scavenging ability . Heptenals, the major components of Cymbocarpum erythraeum oils, have antimicrobial activity against various microorganisms and are more active against the tested fungal species than against bacteria .…”