ARS | Publication request: Accumulation of Maize Chlorotic Dwarf Virus Proteins in Its Plant Host and Leafhopper Vector

Submitted to: Journal Of Virology
Publication Acceptance Date: April 29, 2004
Publication Date: August 1, 2004
Citation: Hamada, C.R., Redinbaugh, M.G., Gingery, R.E., Willie, K., Hogenhout, S.A. 2004. The Genetics Of Virus Resistance In Maize (Zea Mays L.). Journal Of Virology. 325(2):379-388.

Interpretive Summary: Maize chlorotic dwarf virus (MCDV) causes economic losses in the U.S. corn crop in the area where the virus' overwintering host, johnsongrass, and its insect vector, the black-faced leafhopper, overlap. In other plant infecting viruses, specific viral proteins called helper components are important for transmission of the virus by insect vectors. Although previous experiments suggested that a helper component is needed for MCDV transmission, this protein was not identified in the virus genome. In this study, we characterized MCDV proteins and found evidence for a virus-encoded helper component. Identification of this protein may provide new targets to disrupt the virus-vector-plant relationship to prevent disease in corn. IMPACT STATEMENT: Research described in this article provides new information on virus protein function for a group of economically-important cereal-infecting viruses for which little information is available. The new information will provide the basis for future research by ARS and OSU collaborators as well as for the scientific community in general.

Technical Abstract: The genome of Maize chlorotic dwarf virus (MCDV; genus Waikavirus; family Sequiviridae) consists of a positive-sense RNA genome encoding a polyprotein. Three undefined regions of the polyprotein located at the N-terminus of the polyprotein (P78), between coat protein and the nucleotide-binding site (NBS) (P37), and NBS and 3C-like protease (P69) were used to produce His-fusion proteins and to raise antibodies. His-P78 antibodies detected proteins of 50 kDa, 35 kDa and 25 kDa (P25) in purified virus preparations and MCDV-infected plants. The His-P69 antibodies recognized proteins of approximately 30 kDa and 36 kDa, and both the His-P37 and His-P69 antibodies detected a protein of approximately 26 kDa suggesting that this protein contains the NTP-binding site. The P25 recognized by His-P78 antibodies accumulated in vector leafhoppers fed on MCDV-infected plants and is conserved among distantly related MCDV strains. This data suggests that P25 is a putative helper-component protein required for leafhopper transmission.