Recombinase polymerase amplification assay for rapid detection of maize chlorotic mottle virus in maize.

Maize chlorotic mottle virus (MCMV), an important quarantine virus, causes lethal necrosis in maize when coinfected with a potyvirid, which is seriously threatening the production of maize worldwide. In this study, recombinase polymerase amplification (RPA), a novel isothermal DNA amplification and detection technique, was developed to detect MCMV in maize crops. A pair of specific primers was designed based on the conserved sequences of the MCMV coat protein region. The RT-RPA assay was carried out as an isothermal reaction at 38 °C that was complete within 30 min, and no cross-reactivity was detected with other viruses infecting maize in China. The limit of detection of the RT-RPA assay was tenfold lower than that of ordinary RT-PCR. Moreover, this method was successfully applied to test field-collected samples. The newly developed RT-RPA assay offers a reliable, sensitive and efficient method for rapid detection of MCMV in maize in equipment-limited diagnostic laboratories and on-site facilities.