Evidence for multiplication of the leafhopper-borne maize yellow stripe virus in its vector using ELISA and dot-blot hybridization

Maize yellow stripe virus (MYSV) has several features in common with tenuiviruses, but is transmitted by a leafhopper, Cicadulina chinai (Cicadellidae, Hemiptera), rather than planthoppers (Delphacidae, Hemiptera). Herein, MYSV was shown to be propagatively transmitted like tenuiviruses. MYSV RNA was not detected in leafhoppers by dot blot hybridization one day following a 2-day acquisition access period (AAP), but was detected in single or groups of leafhoppers 5-20 days post-acquisition. Likewise, capsid protein of MYSV was not detected by ELISA in single leafhoppers until the third day after the beginning of a 1- or 3-day AAP, but subsequently, mean absorbance values (405 nm) increased gradually, reaching their highest levels 8-14 days post-acquisition. The percentage of ELISA-positive leafhoppers also increased during the same period. Unlike most tenuiviruses, transovarial transmission of MYSV was not detected in 600 C. chinai nymphs that hatched from eggs laid by females that had acquired MYSV from diseased plants. The implications of our findings for MYSV classification are discussed.