Glutaredoxins (GRXs) are small oxidoreductase enzymes that can reduce disulfide bonds in target proteins. The class III GRX gene family is unique to land plants, and
The anaerobic parasite
- NSF-PAR ID:
- 10459553
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- MicrobiologyOpen
- Volume:
- 8
- Issue:
- 10
- ISSN:
- 2045-8827
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Arabidopsis thaliana has 21 class III GRXs, which remain largely uncharacterized. About 80% ofA. thaliana class III GRXs are transcriptionally regulated by nitrate, and several recent studies have suggested roles for these GRXs in nitrogen signaling. Our objective was to functionally characterize two nitrate‐induced GRX genes,AtGRXS5 andAtGRXS8 , defining their roles in signaling and development in theA. thaliana root. We demonstrated thatAtGRXS5 andAtGRXS8 are primarily expressed in root and shoot vasculature (phloem), and that the corresponding GRX proteins display nucleo‐cytosolic subcellular localization. Ectopic expression ofAtGRXS8 in transgenic plants caused major alterations in root system architecture: Normal primary root development, but a near absence of lateral roots. RNA sequencing demonstrated that the roots ofAtGRXS8 ‐overexpressing plants show strongly reduced transcript abundance for many primary nitrate response genes, including the major high‐affinity nitrate transporters. Correspondingly, high‐affinity nitrate uptake and the transport of nitrate from roots to shoots are compromised inAtGRXS8 ‐overexpressing plants. Finally, we demonstrated that the AtGRXS8 protein can physically interact with the TGA1 and TGA4 transcription factors, which are central regulators of early transcriptional responses to nitrate inA. thaliana roots. Overall, these results suggest thatAtGRXS8 acts to quench both transcriptional and developmental aspects of primary nitrate response, potentially by interfering with the activity of the TGA1 and TGA4 transcription factors. -
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