Differences in Levels of Detection for the Maize Stripe Virus Capsid and Major Non-capsid Proteins in Plant and Insect Hosts

Abstract

SUMMARY Antisera to the M r 32000 (32K) capsid and M r 16500 (16·5K) major non-capsid proteins were used for immunological analyses of extracts from maize stripe virus (MStpV)-infected maize (Zea mays) plants and from inoculative Peregrinus maidis, the MStpV planthopper vector. The 32K protein was easily detected in extracts of both MStpV-infected plants and inoculative P. maidis by ELISA and by immunological analysis of Western blots. In a time course study, no 32K protein was detected in P. maidis until 8 days after the beginning of a 5 day acquisition access period on MStpV-infected plants. The percentage of MStpV-positive P. maidis increased with time indicating multiplication of MStpV in P. maidis. The 32K protein was detected only in individual P. maidis that also transmitted MStpV to plant hosts. The 16·5K protein was also detected in MStpV-infected plant hosts but not in extracts of groups or of individual MStpV-inoculative P. maidis. In vitro translation of MStpV virion RNAs in rabbit reticulocyte lysates showed that both the 32K and 16·5K proteins were present in the translation products. The ready detection of the MStpV-coded 32K protein in both plant and insects and detection of the 16·5K protein in only plant hosts is discussed.