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Poster: Molecular & Cellular Plant-Microbe Interactions: MPMI


Identification of silencing suppressor proteins in Maize chlorotic mottle virus
N. BACHELLER (1), H. Garcia-Ruiz (1) (1) University of Nebraska-Lincoln, U.S.A.

Maize Lethal Necrosis (MLN) is a devastating disease of maize caused by a synergistic interaction between Maize chlorotic mottle virus (MCMV) and Sugarcane mosaic virus (SCMV), Wheat streak mosaic virus (WSMV) or Triticum mosaic virus (TriMV). RNA silencing is a prominent antiviral defense system in plants. In single and double infections, MCMV and SCMV activate maize antiviral RNA silencing machinery, resulting in the accumulation of virus-derived small RNAs. Most plant viruses encode silencing suppressor proteins to inactivate RNA silencing and overcome the host defense system. No silencing suppressor has been identified in MCMV. To identify silencing suppressors in MCMV, individual proteins were cloned into binary vectors for transient expression in Nicotiana benthamiana. Proteins with silencing suppression activity were identified by the ability to complement the pathogenicity defect in two different suppressor-deficient viruses. Identification and characterization of silencing in MCMV and SCMV establishes the foundation to further study the molecular mechanisms involved in Maize Lethal Necrosis Disease.