ARS | Publication request: AtGRX4, an Arabidopsis chloroplastic monothiol glutaredoxin, is able to suppress yeast GRx5 mutant phenotypes and respond to oxidative stress

Submitted to: Federation of European Biochemical Societies Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 5, 2008
Publication Date: February 12, 2008
Citation: Cheng, N. 2008. AtGRX4, an Arabidopsis chloroplastic monothiol glutaredoxin, is able to suppress yeast GRx5 mutant phenotypes and respond to oxidative stress. Federation of European Biochemical Societies Letters 582(6):848-854.

Interpretive Summary: Crop plants are vital for feeding our world’s population and a major factor that affects plant development is nature extremes. Many plants have oxidative damage in their DNA, proteins, and lipids that are due to environmental changes, such as heat and drought stress. Enhancing plant crop’s capacity of tolerance to those harmful conditions is a growing challenge for agricultural production in both the US and around the world. In this study, CNRC Scientists identified a novel member of a group of antioxidant enzymes, termed AtGRX4, and demonstrated that this protein plays a critical role in antioxidative stress in plants. These findings provide insights into the utilization of this new tool (gene) to improve crops’ tolerance to environmental stress, which could ultimately have an impact on world crop production.

Technical Abstract: Arabidopsis monothiol glutaredoxin (Grx), AtGRX4, was targeted to chloroplasts/plastids and had high similarity to yeast Grx5. In yeast expression assays, AtGRX4 localized to the mitochondria and suppressed the sensitivity of grx5 cells to oxidants. In addition, AtGRX4 reduced iron accumulation and rescued the lysine auxotrophy of grx5 cells. In plants, AtGRX4 RNA transcripts accumulated in growing tissues. Furthermore, AtGRX4 expression was altered under various stresses. Genetic analysis revealed that seedlings of atgrx4 mutants were sensitive to oxidants. Taken together, these results suggest that AtGRX4 may have important functions in plant growth and development under extreme environments.