Scrophularia mottle virus
Biologische Bundesanstalt für Land- und Forstwirschaft, Braunschweig, Germany
Hein (1959) and
Bercks et al. (1971).
- Scrophularia-Scheckungsvirus (Rev. appl. Mycol. 51: 1241)
An RNA-containing virus with isometric particles about 25-27 nm in diameter. It has a
rather wide host range, is transmitted by beetles of the genus Cionus and is readily
transmissible by inoculation of sap. Found in Germany.
Causes variable amounts of mottling in Scrophularia nodosa
So far known only in Germany; possibly more widely distributed.
Host Range and SymptomatologyScrophularia nodosa
is the only natural host known. Species in 7 out of 19
dicotyledonous families develop systemic symptoms. Species in 9 families develop local
or latent infections. Transmissible by inoculation of sap.
- Datura stramonium. Inoculated leaves develop circular bright yellow spots, which
tend to fuse
systemically infected leaves show light green spots along the veins,
- Vicia faba. Local lesions or brown dots or rings
(Fig.4, right), sometimes with
irregular and poorly defined outlines (Fig.4, left).
- Chenopodium quinoa. Inoculated leaves show irregularly distributed bright yellow
Mild mosaic on systemically infected leaves.
- Antirrhinum majus. Systemically infected leaves develop light green spots
- Antirrhinum majus and Datura stramonium are good sources of virus for
- Vicia faba can be used as a local lesion host.
No information. Isolates differ in symptom expression on Scrophularia nodosa
and on herbaceous test plants.
Transmission by Vectors
The vectors, which transmit the virus only from Scrophularia
are beetles belonging to the family Curculionidae (Cionus
tuberculosis, C. scrophulariae, C. hortulanus, C. alauda
) and unidentified larvae
spp. About 20% of the individuals of these species transmit the virus
Transmission through Seed
Transmission by Dodder
The virus is strongly immunogenic in rabbits; antisera with titres of
in agar gel diffusion tests are readily obtained.
The virus produces one line of precipitate.
The virus belongs to the
and has serological relationships with
Andean potato latent
ononis yellow mosaic
turnip yellow mosaic
The closest serological relationship is to ononis yellow
mosaic virus. However,
Bercks et al. (1971)
detected no serological relationship
between ononis yellow mosaic virus and turnip yellow mosaic virus, and R. Koenig (unpublished)
found only a very distant one. Scrophularia mottle virus has many other properties in common
with the viruses of the tymovirus group.
Stability in Sap
The virus is inactivated when heated to 92-94°C for 10 min
In sap from
infected Datura stramonium,
the virus loses infectivity when diluted 10-5
(assayed on D. stramonium
) or 10-6
(assayed on Antirrhinum majus
inactivation at room temperature takes about 30 days when D. stramonium
is used as
a test plant (R. Bercks, unpublished).
The virus is easily purified by Steeres butanol-chloroform method from A. majus
or D. stramonium
whole plants harvested 4-6 weeks after inoculation. Preparations
free of ribonuclease are obtained using the bentonite method as recommended for
turnip yellow mosaic virus
Dunn & Hitchborn (1965)
Properties of Particles
Virus from D. stramonium
sediments as two components, empty protein shells (T)
and nucleoprotein (B)
Sedimentation coefficients (s20, w
infinite dilution (svedbergs): 54 (T), 116 (B). Preparations from Antirrhinum
three additional components sedimenting at 85, 169 and 200 S. The nature of these
components is unknown but the 169 S component possibly consists of dimers of the B
Partial specific volumes (calculated): 0.74 ml/g (T), 0.69 ml/g (B).
Electrophoretic behaviour: in immunoelectrophoresis in 1% agarose containing 0.05 M
phosphate buffer, pH 7, the virus migrates slowly towards the cathode.
Absorbance at 260 nm (1 mg/ml, 1 cm light path): about 8 for the normal mixture of T and
B components (H. L. Paul, unpublished).
A260/A280: 1.79; corrected and
uncorrected values give the same results for the normal
mixture of T and B components from D. stramonium.
The particles are isometric, c.
26 nm in diameter, usually with poorly defined
The empty shells are penetrated by stains used for electron
microscopy. In structure the virus apparently resembles other
Single-stranded, M. Wt 2.13 x 106
. Molar percentages of nucleotides:
G15.9±0.3; A21.3±0.2; C33.7±0.3; U29.3±0.3 (W. Huth, unpublished).
RNA is about 37% of particle weight.
Protein: The subunits have M. Wt 21,600. The amino acid composition is (moles
percent): ala 6.4; arg 3.8; asx 6.8; cys ?; glx 7.8; gly 5.8; his 1.7; ile 6.8; leu 8.5;
lys 3.7; met 2.2; phe 2.5; pro 10.8; ser 13.3; thr 10.2; try 0.8; tyr 1.7; val 7.7 (H. L.
Paul & B. Wittmann, unpublished).
Relations with Cells and Tissues
Scrophularia mottle virus and ononis yellow mosaic virus
(Gibbs et al., 1966
are closely related serologically but the former is the more closely related to
turnip yellow mosaic virus
During electrophoresis at pH 7 scrophularia mottle virus migrates
towards the cathode whereas ononis yellow mosaic virus migrates towards the anode. The
two viruses also differ in host range and thermal inactivation point (65°C for
ononis yellow mosaic virus).
- Bercks, Huth, Koenig, Lesemann, Paul & Querfurth, Phytopath. Z. 71: 341, 1971.
- Dunn & Hitchborn, Virology 25: 171, 1965.
- Gibbs, Hecht-Poinar, Woods & McKee, J. gen. Microbiol. 44: 177, 1966.
- Hein, Phytopath. Z. 36: 290, 1959.
- Weidemann, Jber. biol. BundAnst. Land- u. Forstw. Braunschweig, 1971: 70, 1972.
Photographs: courtesy of H. Schlobach, Braunschweig.
Naturally infected leaves of different plants of Scrophularia nodosa.
Virus particles from a purified preparation, negatively stained with uranyl
formate. Bar represents 100 nm.
Inoculated leaf of Datura stramonium.
Inoculated leaflets of Vicia faba.
Inoculated leaf of Chenopodium quinoa.
Systemic symptoms in Antirrhinum majus.
Sedimentation behaviour of the virus prepared from D. stramonium.
(Lower diagram) undiluted preparation; (upper diagram) preparation
diluted twofold. Sedimentation is from left to right.