Characterization of Maize Iranian Mosaic Virus and Comparison with Hawaiian and Other Isolates of Maize Mosaic Virus (Rhabdoviridae)

Abstract

Maize Iranian mosaic virus (MIMV) was characterized and compared with isolates of Maize mosaic virus (MMV, genus Nucleorhabdovirus, family Rhabdoviridae) in insect transmission, cytopathology and ultrastructure of infected maize cells, virion proteins and serologically. MIMV is naturally transmitted by Ribautodelphax notabilis, a delphacid planthopper, in Iran. In this study, another planthopper, Peregrinus maidis, vector of MMV, transmitted MIMV with an estimated efficiency of 0.4-1.6% following feeding on MIMVinfected maize plants and 64% following injection of MIMV into the hemolymph, suggesting that P. maidis gut tissues largely blocked MIMV transmission. MIMV and MMV-HI (Hawaii) induced similar cytopathologies in cells of infected maize leaves, with virions budding through inner nuclear and endoplasmic reticulum membranes. In thin sections, virions of MIMV were significantly shorter than those of MMV-HI. Sodium dodecyl sulphate polyacrylamide gel electrophoresis analysis of virions of MIMV, MMV-HI, MMV-CR (Costa Rica) and MMV-FL (Florida) yielded six proteins of which four were identified as the putative G, N, P and M proteins of plant rhabdoviruses. The N, P and M proteins of MIMV migrated faster in gels than those of the MMV isolates indicating a lower molecular weight, whereas the bands corresponding to the G proteins migrated similarly for both viruses. Polyclonal antibodies to MMV-HI failed to react with virions of MIMV in enzyme-linked immunosorbent assay (ELISA) and with MIMV proteins in Western blots. In contrast, these antibodies reacted strongly with MMV-HI and MMV-FL virions in ELISA and with MMV-HI, MMV-CR and MMV-FL proteins in Western blots. Further, in ELISA, polyclonal antibodies to MMV-MR (Mauritius) reacted weakly with MIMV virions but strongly with MMV-HI and MMV-FL virions. Thus, it is concluded that MIMV is a new virus of the Nucleorhabdovirus genus that may be distantly related to MMV.www.blackwell-synergy.com

Cellular and Molecular Aspects of Rhabdovirus Interactions with Insect and Plant Hosts

“…Plant rhabdoviruses apparently multiply at a much lower rate in insect cells than in plant cells. Whereas large accumulations of virions of MMV, MIMV, and MFSV, sometimes packed into paracrystalline arrays, were found in almost all maize leaf cell types (Figure 1a and Figure 2a) (5,58,72), much smaller accumulations of MMV virions, and no paracrystalline arrays, were observed in cells of the insect vector (7) (Figure 1a,b,e, f ). Furthermore, in spite of the systemic infection of MMV in its vector, no major cytopathological effects on neural or other tissues have been detected, and no marked differences in longevity or egg production have been observed in MMV-infected P. maidis (7,8).…”

“…The existence of a midgut infection or midgut escape barrier has been indirectly demonstrated with some plant rhabdoviruses. Intrathoracic injection of MMV or Maize Iranian mosaic virus (MIMV) in planthoppers and SCV in aphids resulted in a much higher proportion of infected individuals than when insects acquired virus by feeding on diseased plants (5,25,91). Direct evidence of midgut infection, midgut escape, and salivary gland infection barriers for MMV in P. maidis has been obtained using immunofluorescence microscopy of dissected insect organs (6) (Figure 2c-e).…”

Infection Rates and Comparative Population Dynamics ofPeregrinus maidis(Hemiptera: Delphacidae) on Corn Plants With and Without Symptoms of Maize Mosaic Virus (Rhabdoviridae: Nucleorhabdovirus) Infection

“…Negative conOctober 2013 HIGASHI AND BRESSAN: MMV AND THE POPULATION DYNAMICS OF P. maidis trol samples were prepared from planthoppers collected from the rearing colony. For positive controls, fourth-instar nymphs were microinjected with a clariÞed extract prepared from MMV-infected leaves (Ammar et al 2005). Injected planthoppers were individually conÞned to 2-wk-old noninfected GCB seedlings contained within cylindrical PVC cages (13 by 13 by 30 cm) and given a 10-d incubation period to allow the virus to replicate into the planthopperÕs hemocoel.…”

Transcriptome profiling of whitefly guts in response to Tomato yellow leaf curl virus infection

“…Persistent viruses, whether propagative or nonpropagative, can be transmitted to plants after injection into the insect hemolymph [ 15 ]. In many cases, injected viruses are transmitted at higher rates than orally acquired viruses [ 16 , 17 ]. Microscopic studies have shown that TYLCV virions is extensively localized in the filter chamber and cross the epithelial cells in the midgut [ 6 , 18 ].…”