|ZHAO, R - China Agricultural University|
|WANG, N - China Agricultural University|
|LIU, S - China Agricultural University|
|FAN, ZAIFENG - China Agricultural University|
|ZHOU, TAO - China Agricultural University|
Submitted to: Acta Virologica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/25/2016
Publication Date: 12/1/2016
Citation: Zhao, R., Wang, N., Liu, S., Ling, K., Fan, Z., Zhou, T. 2016. p22 of tomato chlorosis virus, an ribonucleic acid silencing suppressor, is naturally expressed in the infected plant. Acta Virologica. 60:423-425.
Interpretive Summary: Tomato chlorosis virus (ToCV) has emerged as a serious disease problem in field and greenhouse tomato productions in the U.S. and worldwide. This whitefly transmitted virus is difficult to control. An effective and economical means of controlling a viral disease is to use a tomato cultivar with resistance. However, viruses can develop a counter defense mechanism using virus-encoded gene (s), such as a ribonucleic acid (RNA) silencing suppressor, leading to resistance breaking down in the plant. One of these genes in ToCV which encodes a protein called p22 has been shown to be a gene silencing suppressor. To date, the physical presence of the p22 protein in an infected host plant has not been determined. In the present study, an ARS scientist collaborating with others at the China Agricultural University revealed, for the first time, the natural expression of p22 in a ToCV-infected plant (Nicotiana benthamiana) using an antibody targeting the protein. Identification of the presence of the RNA silencing suppressor may help us to understand the mechanism of virus pathogenicity, and lead to development of a more durable virus resistance cultivar. These findings are of great interest to breeders and geneticists working to develop virus resistant crops.
Technical Abstract: Tomato chlorosis virus (ToCV) in the genus Crinivirus of the family Closteroviridae, is an economically important emerging disease of tomato worldwide. This whitefly-transmitted virus is difficult to control. The best strategy in viral disease management is through the use of a resistant cultivar. However, viruses often develop a counter-defense measure using virus-encoded gene(s) for a RNA silencing suppressor. P22 gene in ToCV has been identified by others as an RNA silencing suppressor, but its presence in the ToCV-infected plant has not been determined. Since an antibody is not yet available for p22, until now, there is no direct evidence showing p22 is expressed naturally in the ToCV infected plants. The objective of the present study was to provide a direct physical evidence for the presence of p22 protein in a ToCV-infected plant. By developing an infectious clone of ToCV with a triple-FLAG tag fused to the C-terminus of p22, using an anti-FLAG monoclonal antibody, we present here, for the first time, a physical evidence for the natural expression of p22 in ToCV-infected Nicotiana benthamiana plant. Understanding of the gene silencing suppressor may help us in developing a tomato cultivar with durable disease resistance to ToCV.