Purification and serological detection of maize yellow mosaic virus

Authors: Wilson, Jennifer; Willie, Kristen; Khatri, Nitika

Submitted to: Archives of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/29/2025
Publication Date: 3/14/2025
Citation: Wilson, J.R., Willie, K.J., Khatri, N. 2025. Purification and serological detection of maize yellow mosaic virus. Archives of Virology. 170: Article #80. https://doi.org/10.1007/s00705-025-06249-x.
DOI: https://doi.org/10.1007/s00705-025-06249-x

Interpretive Summary: Maize yellow mosaic virus (MaYMV) is an emerging virus that infects maize and many other grass species such as wheat and barley. The virus has been reported in North and South America, Asia, and Africa. Detection of the virus is challenging and it is suspected that the virus has been present for much longer than when it was first reported in 2013. To aid in detection of the virus, we developed an antibody and diagnostic test that is much more cost effective than current methods of diagnosing MaYMV in infected plants. First, we developed a biochemical purification technique that can extract large quantities of virus particles from maize plants. This allowed for visualization of the virus particles for the first time under the electron microscope. Next, this purified virus preparation was used to generate an antibody that recognizes the virus. Finally, we showed that this antibody is effective at detecting MaYMV when used in a variety of different diagnostic techniques, with no false positive detection of closely related viruses. This antibody and the associated diagnostic tests will be a great resource for detecting MaYMV infection in the field and can be used to advance research on the virus such as understanding its prevalence and distribution. The cost-effective nature of the test also allows for breeders to conduct large-scale germplasm screenings to identify resistance to MaYMV and ultimately develop resistant varieties to help growers manage this emerging virus.

Technical Abstract: Maize yellow mosaic virus (MaYMV) is an emerging polerovirus first reported in maize in China in 2013 but has since been reported in Africa and the Americas. Due to its novelty, no antibodies or serological diagnostics for the virus existed prior to the current study. Here we developed the first purification method for maize yellow mosaic virus with the goal of generating an antibody and subsequent diagnostics. Yields of 0.634-1.275 milligram virus per kilogram of maize tissue were obtained, which is comparable to yields for other grass-infecting poleroviruses. Under the electron microscope, purified virus particles appear icosahedral in shape and roughly 30 nm in diameter. A polyclonal antibody was generated against the gradient-purified virus preparation and cross absorbed to uninfected maize tissue. The antibody is effective for detection of MaYMV via enzyme linked immunosorbent assay (ELISA) and western blot. The ELISA can detect virus in quantities as little as 0.395 ug and in 1:64 dilutions of infected plant extract. The antibody had little to no cross reactivity with five closely related viruses via ELISA. After protein gel electrophoresis and antibody detection, protein bands corresponding in size to two virus structural proteins can be seen: the coat protein of roughly 21 kDa and the readthrough protein, around 72 kDa. Finally, virus particles purified using this protocol are transmissible by the primary aphid vector, Rhopalosiphum maidis, and cause systemic, symptomatic infection of maize plants, indicating that vector transmissibility and infectivity of the virus particles is preserved during purification.