|LIM, GAH-HYUN - University Of Kentucky|
|HOEY, TIMOTHY - University Of Kentucky|
|ZHU, SHIFENG - University Of Kentucky|
|CLAVEL, MARION - Universite De Perpignan|
|Navarre, Duroy - Roy|
|KACHROO, AARDRA - University Of Kentucky|
|DERAGON, JEAN-MAC - Universite De Perpignan|
|KACHROO, PRADEEP - University Of Kentucky|
Submitted to: PLoS Pathogens
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/22/2018
Publication Date: 3/7/2018
Citation: Lim, G., Hoey, T., Zhu, S., Clavel, M., Navarre, D.A., Kachroo, A., Deragon, J., Kachroo, P. 2018. COP1, a negative regulator of photomorphogenesis, positively regulates plant disease resistance via double-stranded RNA binding proteins. PLoS Pathogens. 14(3):31006894. https://doi.org/10.1371/journal.ppat.1006894.
Interpretive Summary: Plant diseases threaten food security by reducing yield and quality, and reduce grower profitability. Scientists at the University of Kentucky, Universite de Perpignan Via Domitia in France, and the USDA-ARS in Prosser Washington identified a group of plant proteins that bind RNA and have key roles in how plants resist bacterial and viral diseases. These proteins are a part of a complex plant response to disease that ultimately can result in the plant resisting disease. As mechanisms like these are discovered, it will become increasingly possible to produce plants with superior disease resistance and preserve plant yields, reduce pesticide inputs and protect profitability.
Technical Abstract: The Arabidopsis genome encodes five double-stranded RNA binding (DRB) proteins which have been characterized for their roles in siRNA pathways. Here, we show that DRB proteins play an important role in plant defense against viral and bacterial pathogens by regulating the levels and signaling mediated by the cognate resistant (R) proteins. While all five DRB proteins were required for R-mediated resistance against turnip crinkle virus (TCV), only DRB1, DRB2, and DRB4 were required for bacterial resistance. DRB3 and DRB5 acted as negative regulators of bacterial resistance because the loss of DRB3/5 restored resistance in the drb1, drb2, and/or drb4 mutant plants. Interestingly, overexpression of DRB2 mimicked the drb4-like zippy phenotype and compromised both basal and R-mediated resistance against bacterial pathogens in a TAS3-siRNA-independent manner. Together, our results suggest that DRB isoforms have similar as well as distinct functions in bacterial and viral defense.