|CHEN, HUI - Kansas State University|
|Tiley, Helene - Ellie|
|TIAN, BIN - Kansas State University|
|TRICK, HAROLD - Kansas State University|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/3/2021
Publication Date: 7/19/2021
Citation: Hao, G., Naumann, T.A., Chen, H., Bai, G., Tiley, H.C., McCormick, S.P., Tian, B., Trick, H.N., Kim, H.-S., Proctor, R. 2021. Host-induced silencing of a Fusarium graminearum effector enhances wheat resistance to Fusarium Head Blight. [abstract].
Technical Abstract: Fusarium head blight (FHB) caused by the fungus Fusarium graminearum is one of the most devastating diseases of wheat and barley worldwide. Effectors produced by plant pathogenic fungi play important roles in plant and microbe interactions. F. graminearum is predicted to produce hundreds of effectors. However, the functions of most of these effectors remain uncharacterized. In this study, we characterized an effector FGSG_04563 (designated as FgNls1), which was predicted to contain multiple eukaryotic nuclear localization signals (NLS). Using Agrobacterium-mediated transient expression, accumulation of a fusion protein of FgNls1-GFP was observed in the nuclei of Nicotiana benthamiana. Further, co-immunoprecipitation assays using FgNls1-GFP fusion protein confirmed its nuclear localization in N. benthamiana. Expression of FgNLS1 gene was induced in F. graminearum infected wheat heads. Compared to wild-type F. graminearum, Fgnls1 mutants significantly reduced their ability to cause FHB, thereby, had less deoxynivalenol (DON) contamination in infected wheat heads. FgNls1 also suppressed cell death induced by Bax when co-expressed with Bax in N. benthamiana, suggesting that FgNls1 can suppress plant immunity. Our analyses showed that transgenic wheat plants that silenced FgNLS1 expression had significant lower FHB severity than the non-transgenic control plants. These results indicate that host induced gene silencing that can suppress expression of F. graminearum effectors is a promising novel approach to improving FHB resistance and reducing mycotoxin contamination in wheat.