Monothiol glutaredoxin DaGrxB couples iron homeostasis with redox balance to orchestrate development and virulence in the peach shoot blight fungus Diaporthe amygdali
- 1Yangzhou University
Abstract
Peach shoot blight (PSB), caused by Diaporthe amygdali, is one of the most devastating fungal diseases affecting peach production worldwide. Glutaredoxins (Grxs) are ubiquitous redox-regulatory proteins involved in antioxidant defense and iron metabolism, yet their functions in phytopathogenic fungi remain largely unknown. Here, we identified four Grxs (DaGrxA-DaGrxD) in D. amygdali. Among them, DaGrxB, a monothiol glutaredoxin, is the sole member essential for vegetative growth, asexual reproduction and virulence. DaGrxB interacts with iron-regulatory transcription factors DaHapX and DaSreA and modulates their activities via iron-dependent nucleocytoplasmic shuttling, coordinating iron acquisition and storage gene expression. During infection, D. amygdali encounters a biphasic iron environment: an inherently iron-limited host environment at early stages (1-2 dpi) followed by host-mediated iron excess (3-4 dpi), and DaGrxB is essential for navigating this transition. Consistently, deletion of either DaHAPX or DaSREA significantly reduced virulence, confirming that iron homeostasis is a critical determinant of D. amygdali virulence. Notably, deletion of DaGRXB disrupts Fe-S cluster biosynthesis, causing mitochondrial Fe2+ accumulation, impaired aconitase activity, and reduced ATP production, which triggers constitutive activation of the GSH-dependent antioxidant system, with elevated GSH/GSSG ratios, increased GR and GST activities, and reduced H2O2 levels. Exogenous GSH and H2O2 depletion both reduced virulence, suggesting that disturbed redox balance directly contributes to attenuated virulence. Additionally, the Trx domain assists the Grx domain in nucleocytoplasmic translocation through intramolecular interactions. Finally, LDH-delivered dsRNA targeting DaGRXB effectively controls PSB. Collectively, these findings reveal how a monothiol glutaredoxin integrates iron homeostasis, redox balance and virulence in a plant pathogen, providing a foundation for RNAi-based disease management.
Related
- Structural Insights into a Fusion Protein between a Glutaredoxin-like and a Ferredoxin-Disulfide Reductase Domain from an Extremophile Bacterium
- TEAD4 Regulates apical domain homeostasis and cell-positioning to maintain the trophectoderm lineage during mouse blastocyst development
- Extracellular vesicles orchestrate immune suppression and immune exclusion in cancer.
- TopBP1 condensates orchestrate nuclear actin assembly to ensure genome stability
- A Novel Drp1-Golph2 Tether Mediates Mitochondria-Golgi Spatial Association to Orchestrate Mitochondrial Function and Hepatic Lipid Catabolism Across Vertebrates
BibTeX
@misc{yang2026monothiol,
title = {{Monothiol glutaredoxin DaGrxB couples iron homeostasis with redox balance to orchestrate development and virulence in the peach shoot blight fungus Diaporthe amygdali}},
author = {L. Yang and X. Liu and L. Xiong and Y. Zhang and Y. Jing and H. Shi and Z. Pan and S. Cao and L. Li and Y. Liang and Z. Ji},
howpublished = {bioRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.28.755239},
url = {https://www.biorxiv.org/content/10.64898/2026.09.28.755239v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Monothiol glutaredoxin DaGrxB couples iron homeostasis with redox balance to orchestrate development and virulence in the peach shoot blight fungus Diaporthe amygdali
AU - L. Yang
AU - X. Liu
AU - L. Xiong
AU - Y. Zhang
AU - Y. Jing
AU - H. Shi
AU - Z. Pan
AU - S. Cao
AU - L. Li
AU - Y. Liang
AU - Z. Ji
PY - 2026
DA - 2026/09/28
PB - bioRxiv
DO - 10.64898/2026.09.28.755239
UR - https://www.biorxiv.org/content/10.64898/2026.09.28.755239v1
AB - Peach shoot blight (PSB), caused by Diaporthe amygdali, is one of the most devastating fungal diseases affecting peach production worldwide. Glutaredoxins (Grxs) are ubiquitous redox-regulatory proteins involved in antioxidant defense and iron metabolism, yet their functions in phytopathogenic fungi remain largely unknown. Here, we identified four Grxs (DaGrxA-DaGrxD) in D. amygdali. Among them, DaGrxB, a monothiol glutaredoxin, is the sole member essential for vegetative growth, asexual reproduction and virulence. DaGrxB interacts with iron-regulatory transcription factors DaHapX and DaSreA and modulates their activities via iron-dependent nucleocytoplasmic shuttling, coordinating iron acquisition and storage gene expression. During infection, D. amygdali encounters a biphasic iron environment: an inherently iron-limited host environment at early stages (1-2 dpi) followed by host-mediated iron excess (3-4 dpi), and DaGrxB is essential for navigating this transition. Consistently, deletion of either DaHAPX or DaSREA significantly reduced virulence, confirming that iron homeostasis is a critical determinant of D. amygdali virulence. Notably, deletion of DaGRXB disrupts Fe-S cluster biosynthesis, causing mitochondrial Fe2+ accumulation, impaired aconitase activity, and reduced ATP production, which triggers constitutive activation of the GSH-dependent antioxidant system, with elevated GSH/GSSG ratios, increased GR and GST activities, and reduced H2O2 levels. Exogenous GSH and H2O2 depletion both reduced virulence, suggesting that disturbed redox balance directly contributes to attenuated virulence. Additionally, the Trx domain assists the Grx domain in nucleocytoplasmic translocation through intramolecular interactions. Finally, LDH-delivered dsRNA targeting DaGRXB effectively controls PSB. Collectively, these findings reveal how a monothiol glutaredoxin integrates iron homeostasis, redox balance and virulence in a plant pathogen, providing a foundation for RNAi-based disease management.
ER -