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POSTERS: Plant defense response

Towards Understanding the Molecular Mechanisms Underlying Fhb1-mediated Resistance Against Fusarium graminearum
Lovepreet Singh - University of Maryland. Nidhi Rawat- University of Maryland College Park, Shunyuan Xiao- Inst for Bioscience & Biotechnology Res

Fusarium head Blight (FHB), caused by Fusarium graminearum, is one of the most devastating diseases of wheat. Fhb1 is the most stable and effective quantitative trait locus (QTL) that confers resistance against FHB. A pore forming toxin-like (PFT) gene has been identified as the underlying gene for Fhb1 mediated resistance. PFT is predicted to be a lectin protein with two agglutinin domains and one bacterial pore forming domain. The objective of this study is to understand the molecular mechanism by which PFT confers resistance to F. graminearum. The Arabidopsis - F. graminearum interaction has been demonstrated to be an effective pathosystem for studying basal resistance against F. graminearum. PFT has been ectopically expressed in wild-type and various Arabidopsis mutant backgrounds to determine the defense pathway(s) PFT may function in. Meanwhile, PFT was fused with GFP and RFP at the N or C terminus and transiently expressed in Nicotiana benthamiana for determining its sub-cellular localization. Our preliminary results showed that G(R)FP-PFT signal was found in the tonoplast, multi-vesicular bodies and the apoplast, suggesting that PFT is membrane associated protein and secreted out of the cell via exocytosis. Stable transgenic Arabidopsis plants expressing G(R)FP-PFT will soon be used to test their response against F. graminearum and confirm PFT’s subcellular localization.