TITLE:
Comparative Analysis of RNAi Suppression Activity of Proteins from Two Disparate Viruses
AUTHORS:
Sudhanshu Sekhar Das, Neeti Sanan-Mishra
KEYWORDS:
MYMIV-AC2, FHVB2, Agroinfiltration, RNA Silencing Suppressor (RSS), Reversal of GFP Silencing Assay
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.5 No.12,
May
28,
2014
ABSTRACT: RNAi is an efficient
surveillance machinery that plays a robust defensive role in shielding plant
and animal hosts against viral infections. In counter-defense viruses encode
suppressor proteins that have the ability to restrict the RNAi machinery to
ensure successful systemic invasion. The B2 protein of insect Flock House Virus (FHV-B2) and AC2
protein of Mungbean Yellow Mosaic India Virus (MYMIV-AC2) are two well-characterized suppressors of RNAi, capable of
reversing reporter gene silencing. In this study, we compared the strength of
the two suppressors by assaying for the degree of RNAi reversion and the
duration of sustaining the reversal in
planta. The suppression activity was observed by assaying for GFP
fluorescence at 3 dpi, 7 dpi and 14 dpi. The phenotypic observations were
corroborated with small RNA Northern Blotting and semi-quantitative RT-PCR. The
results indicate that suppressor strength of FHVB2 is comparable to MYMIV-AC2,
although they are encoded by virus infecting host from two different eukaryotic
kingdoms. This study will provide new insights to dissect the conservation in
the RNAi pathways during the host-virus interactions.