The Abutilon Mosaic Virus (AbMV) in Different Leaf Tissues of Several Host Species of Malvaceae

Abstract

Cytological changes occurring after infection by Abutilon Mosaic Virus (AbMV) have been investigated in the host plants Abutilon sellovianum Rgl., Malva parviflora L., Malva silvestris L., and Sida micrantha Schr. Two types of virus‐like inclusions were found in different tissues: particles of 16–18 nm in diameter and elongated filaments with 6–8 nm in diameter. The particles are detectable in the nuclei (Abutilon sellovianum, Malva spec.) and cytoplasm (Malva spec.) of cells in the bundle area, and the filaments accumulate in the nuclei (Sida micrantha) and the plastids (Malva spec.) of leaf mesophyll cells.

Indian Cassava Mosaic Virus: Ultrastructure of Infected Cells

“…Inclusions of virus particles similar to those seen in ICMV-infected leaves are found in leaves infected with beet curly top (BCTV) (Esau, 1977;Esau & Magyarosy, 1979), Venezuelan tomato yellow mosaic (Lastra & Gil, 1981), euphorbia mosaic (EuMV) (Kim & Flores, 1979;Kim & Fulton, 1984), bean golden mosaic (BGMV) (Kim et al, 1978), ACMV (Horvat & Verhoyen, 1981 ;Adejare & Coutts, 1982), jatropha mosaic (JMV) (Kim et aL, 1986), chloris striate mosaic (CSMV) (Francki et al, 1979), tomato yellow leaf curl (Russo et al, 1980) and mungbean yellow mosaic (MYMV) (Thongmeearkom et al, 1981) geminiviruses. ICMV particles, however, were always seen as irregularly shaped inclusions, and were never found in tubular arrays as exhibited by abutilon mosaic virus (Jeske et al, 1977;Jeske & Schuchalter-Eicke, 1984) or MYMV (Thongmeearkom et al, 1981), nor as crystalline sheets of virus particles as seen with tomato golden mosaic virus (Rushing et al, 1987), BGMV (Kim et al, 1978) or maize streak virus (Bock, 1974). Ordered rows or rod-like aggregates of virus particles similar to those seen with tomato leaf curl virus (Osaki & Inouye, 1978), CSMV (Francki et al, 1979) or BCTV in spinach (Esau, 1977) were never seen.…”

Single-stranded DNA from abutilon mosaic virus is present in the plastids of infected Abutilon sellovianum

“…Photographs were taken with Ektachrome tungsten-light film, Kodak. For electron microscopic analysis the fractions were fixed sequentially in 4% (vol/vol) glutaraldehyde in HAB and in 1% osmium tetroxide in 0.15 M sodium phosphate (pH 7.5), embedded in 1% agarose, and processed as described (9).…”

“…After infecting Malva parviflora, comparable filaments could be detected in the chloroplasts of mesophyll cells, because they form paracrystalline inclusions (8,9).…”

“…The disease is transmitted by the whitefly Bemisia tabaci, which is not indigenous to Europe; therefore, cuttings were used for propagation of infected plants. The corresponding virus-like twin particles had been found (8,9) in the nuclei of the phloem-associating cells of various host plants. Structures called "chains of pearls" that contain the AbMV DNA and transmit the disease can be isolated from AbMV-infected plants (10).…”

“…Photographs were taken with Ektachrome tungsten-light film, Kodak. For electron microscopic analysis the fractions were fixed sequentially in 4% (vol/vol) glutaraldehyde in HAB and in 1% osmium tetroxide in 0.15 M sodium phosphate (pH 7.5), embedded in 1% agarose, and processed as described (9).Isolation of Plastid DNA. Plastids were lysed in 10 mM Tris HCl, pH 7.5/100 mM EDTA/1% N-lauroylsarcosine at 50°C for 10 min, treated with proteinase K at 100 ,ug/ml (Serva) overnight, and freed from proteins by phenol/chloroform, 1:1 (vol/vol), extraction.…”