In the intricate dance between plants and viruses, a new partner has been identified that could reshape our understanding of viral spread and potentially open doors to innovative agricultural solutions. Researchers have discovered that a protein from the Broad bean wilt virus 2 (BBWV2), known as VP37, hijacks a host protein called HSP70–HSP90 organizing protein (HOP) to facilitate its movement between plant cells. This finding, published in the journal *Plant Stress*, could have significant implications for crop protection and viral resistance strategies.
The study, led by Seok-Yeong Jang from the Department of International Agricultural Technology at Seoul National University, reveals that VP37 interacts specifically with NbHOP, a protein that typically resides in the nucleus of plant cells. However, when VP37 is present, NbHOP is relocated to the plasmodesmata—the tiny channels between plant cells that viruses exploit to spread. “This relocalization is crucial for the virus to move efficiently from cell to cell,” explains Jang. “By understanding this interaction, we can start to think about ways to disrupt it and potentially limit the virus’s spread.”
The researchers employed a variety of techniques, including yeast two-hybrid assays, co-immunoprecipitation, and bimolecular fluorescence complementation, to confirm the interaction between VP37 and NbHOP. They also demonstrated that the C-terminal region of the TPR2B domain in NbHOP is essential for binding to VP37. Functional assays further showed that silencing NbHOP significantly reduced both systemic infection and cell-to-cell movement of BBWV2, while overexpressing NbHOP enhanced viral movement.
This research builds on previous findings that VP37 associates with HSP90, suggesting that the virus co-opts the HSP90–HOP chaperone complex to ensure proper folding, stabilization, and tubule formation at the plasmodesmata. “The HSP90–HOP module is a key host machinery that the virus exploits for its intercellular trafficking,” says Jang. “By targeting this complex, we might be able to develop new strategies to control viral infections in crops.”
The commercial impacts of this research could be substantial. Broad bean wilt virus 2 is a significant pathogen affecting a range of leguminous crops, including broad beans, peas, and soybeans. By understanding how the virus spreads, researchers can develop targeted interventions that disrupt this process, potentially leading to more resilient crop varieties and reduced losses for farmers.
Moreover, the discovery highlights the broader role of HOP in plant–virus interactions, suggesting that similar mechanisms might be at play in other plant viruses. This could open up new avenues for research into viral resistance and crop protection strategies. “This study uncovers an unrecognized role of HOP in plant–virus interactions,” Jang notes. “It’s a piece of the puzzle that we didn’t have before, and it could be crucial for developing new control measures.”
As the agricultural sector faces increasing pressures from climate change, pests, and diseases, innovative solutions like those suggested by this research become ever more critical. By delving into the molecular intricacies of plant–virus interactions, scientists are paving the way for a future where crops are not just more productive but also more resilient against the ever-evolving threats they face.