Etiology of a Mosaic Disease of Radish and Lettuce and Sequencing of the Coat Protein Gene of the Causal Agent in Saudi Arabia
This study aimed at identifying the causal agent inducing
virus-like symptoms on radish and lettuce plants in Riyadh Region, Saudi
Arabia. Mottling, chlorosis and mosaic symptoms were observed on lettuce
(Lactuca sativa Linn.) and radish (Raphanus sativus Linn.)
plants in two areas in Riyadh region. Mosaic symptoms were observed on
L. sativa, R. sativus, Eruca sativa Mill and Brassica
rapa Linn., whereas local lesions were observed on Chenopodium
ammaranticolor Coste and Reyn., which were mechanically inoculated
with sap from infected radish and lettuce plants. Electron microscopy
revealed filamentous flexuous particles typical of potyviruses. The aphid
Brevicoryne brassicae transmitted the virus to lettuce and radish
in a non-persistent manner. Turnip mosaic virus (TuMV) was the only detected
virus by double antibody sandwich-enzyme linked immunosorbent assay among
five viruses suspected of such disease symptoms. Amplification of total
RNA extracted from infected lettuce and radish plants yielded 1-1.2 kbp
using three degenerate primers which were designed for potyvirus group
detection and 985 bp complementary DNA (cDNA) fragments using a specific
oligonucleotide primer for TuMV detection. Nucleic acid sequence analysis
of TuMV-L-SA revealed a range of 85.3 to 90.9% sequence identity with
other TuMV isolates obtained from the GenBank. However, the TuMV-Ra-SA
revealed a range of 87.7 to 94.1% sequence identity. The sequence similarity
between TuMV-L-SA and TuMV-Ra-SA investigated in the current study was
89%. To our knowledge, this is the first report of TuMV on lettuce and
radish in Saudi Arabia.
Turnip mosaic virus (TuMV) is an RNA virus which belongs to the genus Potyvirus,
within the potyviridae family of plant viruses (Barnett
et al., 1995; Provvidenti et al., 1996).
All potyviruses have flexuous filamentous particles 700-750 nm long, each of
which contains a single copy of the genome, which is a single-stranded positive
sense Ribonucleic acid (RNA) molecule. The size of potyviruses RNA is about
10000 nucleotides long. The genomes of potyviruses have a single open reading
frame that is translated into a single large polyprotein, which is hydrolysed,
after translation, into several proteins by virus-encoded proteinases (Riechmann
et al., 1992). Turnip mosaic virus is a widely spread and economically
important virus (Walsh and Jenner, 2002). It has been
ranked among the five most damaging vegetable viruses worldwide (Tomlinson,
1987) and the only potyvirus known to infect brassicas (Walsh
and Jenner, 2002). It was first reported in crucifers by Gardner
and Kendrick (1921) and Schultz (1921) in the United
States of America. The virus is geographically widespread, of cosmopolitan distribution
and has been reported in North America, Europe, Africa, Asia, Australia and
New Zealand (Tomlinson and Ward, 1978; Rybicki
and Hughes, 1990; Walsh and Tomlinson, 1985; Edwardson
and Christie, 1991; Powell and Lindquist, 1992). Turnip
mosaic virus has a wide host range and infects over 318 plant species in 156
genera of 43 plant families including many important crops such as cruciferae,
compositae, chenopodiaceae, leguminosae and caryophyllaceae, weeds and is also
known to infect monocots (Chen et al., 2003;
Edwardson and Christie, 1991; Green
and Deng, 1985). Turnip mosaic virus infects many crops, including cabbage
and other brassica vegetables, oilseed rape, chicory, horseradish, lettuce,
peas and rhubarb (Shattuck, 1992). TuMV, like other
potyviruses, is transmitted by aphids in the non-persistent manner (Shukla
et al., 1994). Eighty nine aphid species were reported to transmit
TuMV in a non-persistent manner including Myzus persicae and Brevicoryne
brassicae (Walsh and Jenner, 2002). There are potyvirus
isolates that appear serologically similar to TuMV when tested with polyclonal
antisera that do not readily infect brassicas (Lesemann
and Vetten, 1985). Recently, TuMV which has been reported to infect garden
rocket in Saudi Arabia, has been described by Al-Saleh et
al. (2008). Subsequent to that investigation, viral symptoms were observed
on naturally growing lettuce and radish plants in Riyadh region. That fact encouraged
carrying out of the present study with the aim of isolation, identification
and molecular characterization of the causal agent (s) infecting these crops
in the central region of Saudi Arabia.
MATERIALS AND METHODS
Source and Host Range of the Virus Isolates
Samples of lettuce and radish plants growing naturally at Al-Hair and Al-Oyayna
areas in Riyadh region, Saudi Arabia and showing mottling, mosaic and chlorosis
symptoms (Fig. 1) were collected during the spring of 2007.
Seeds of 14 plant species were germinated in small pots filled with a soil mix
of sand and peatmoss in the ratio of 2:1. The plant species were: Raphanus
sativus L., Eruca sativa Mill, Brassica rapa L., B. oleracea
L., Lactuca sativa Linn, Spinacea oleracea, Lycopersicum
esculentum L., Datura stramonium L., Chenopodium ammaranticolor
Cost and Reyn, Solanum nigrum L., Gomphrena globosa, Nicotiana
tabaccum L. and N. glutinosa L. The seedlings were transplanted in
large pots filled with the same soil mixture.
|| Field symptoms of Turnip mosaic virus (TuMV) on (a) radish
and (b) lettuce plants
Three seedlings of each of the plant species were transplanted in each of six
pots. Inoculum was prepared by separately grinding leaves of R. sativus
and Lactuca sativa showing mosaic symptoms, in 0.01 M potassium phosphate
buffer (Winlab, United Kingdom), pH 7.0, in a ratio of 1:4 and then filtered
through cheese cloth. Two sets of seedlings (two pots per each plant species)
of the above plants were separately inoculated with the prepared inoculum from
radish and lettuce after being dusted with carborundum (300 mesh)( Fisher Scientific,
USA). One pot containing three seedling of each plant species was inoculated
with sap from healthy radish or lettuce prepared in the same way as control.
The seedlings were then rinsed with distilled water and kept in the greenhouse
(Chen et al., 2003). These experiments were repeated
The leaf dip method described by Hill (1984) was adopted.
Leaf pieces of infected lettuce and radish plants were sliced at the edges and
immersed several times in a drop of potassium phosphate buffer, pH 7, on carbon
coated copper grids. Excess buffer was removed using Whatman filter papers (Whatman
international Ltd., England). A drop of 1% phosphotungstic acid (BDH Chemicals
Ltd., England) was placed on each grid for 45 sec and was then removed using
Whatman filter papers. The grids were then observed in the electron microscope
for virus detection.
Brevicoryne brassicae L. were collected from uninfected radish plants
in Oyaynah area and left starving for an hour in Petri dishes size 94/16 (bottger,
Germany). The aphids in some of these plates were then allowed to feed briefly
on pieces of healthy radish leaves subsequent to the starvation period, while
others were allowed to feed for 3 min on pieces of radish leaves infected with
TuMV and showing mosaic symptoms. After the insects in both groups were fed
for 3 min, they were quickly transferred singly by a brush onto healthy radish
seedlings (5 insects/plant. 10 plants/treatment). The aphids in both groups
were allowed to feed on these seedlings for 2 min after their transfer. The
seedlings were then sprayed with an insecticide (cyprine 100 EC) to kill the
insects. Seedlings were kept in the greenhouse and observations regarding symptoms
expression were recorded. Lettuce plants were tested in the same manner (Shattuck,
Serological Detection of the Virus
DAS-ELISA described by Clark and Adams (1977) was
used for the detection of the virus that induced symptoms in lettuce and radish.
ELISA kits of Alfalfa Mosaic Virus (AMV), Cucumber Mosaic Virus (CMV) and Tomato
Spotted Wilt Virus (TSWV), Lettuce Mosaic Virus (LMV) and Turnip Mosaic Virus
(TuMV) were purchased from Agdia Inc., (Indiana, USA). Steps of ELISA procedure
were followed as described on the label by Agdia, Inc. Each of four micro titer
plates was coated with antibodies of each virus after being diluted with the
coating buffer. Subsequent to incubation and washing, aliquots of 100 μL
of each of the samples which were extracted in the extraction buffer, were added
in two wells of each plate. One hundred microliters of the proper dilutions
of the relevant antibody-alkaline phosphatase conjugate were dispensed in the
wells of each plate subsequent to washing plates from samples sap. P-nitrophenyl
phosphate solution was then added in the wells of each plate after washing from
the conjugate solution. The plates were incubated for 1 h and the reaction was
then stopped using 3 M NaOH. The plates were read at 405 nm in the plate reader
(minireader II, Karl Kolb, Germany).
RNA Extraction and RT-PCR
The SV-Total RNA Isolation System (Promega, USA) was used for total RNA
extraction from infected and uninfected lettuce and radish plants. The QIAGEN
One Step RT-PCR Kit (QIAGEN, USA) was used to perform the RT-PCR according to
the manufacturers instructions. The oligonucleotide primers used for Potyvirus
degenerate primer were designed according to Hsu et al.
(2005) as follow: PNIbF1 5`-ggB aaY aaT agt ggN caa cc-`3, PNIbF5 5`-gcc
agc cct cca ccg tNg tNg aYa-`3 and PCPR1 5`- GGG GAG GTG CCG TTC TCD ATR CAC
CA -`3 (where B = C, G and T, Y = C and T, N = A, C, G and T, D = A, G and T
and R = A and G). The oligonucleotide primers used for TuMV detection were designed
according to Sanchez et al. (2003) as follows:
the upstream primer Tu 8705- 8726: 5`-CAA GCA ATC TTT GAG GAT TAT G-`3 and the
downstream primer Tu 9690-9669 : 5`-TAT TTC CCA TAA GCG AGA ATA C-3` were used.
RT-PCR was performed according to QIAGEN manufacturers (QIAGEN, USA) recommendations.
Briefly, 10 μL of 5xQIAGEN One Step RT-PCR Buffer, 2 μL of 10 mM dNTP
Mix, 10 μL of 5x Q-Solution, 2 μL of 10 pmol of each complementary
and homologous primers, 2 μL of QIAGEN One Step RT-PCR Enzyme Mix, 5-10
units/reaction of RNase inhibitor, A total of 5 μL (200 ng) of RNA was
added to the one-step and RNase-free water to 50 μL. The master mix was
mixed gently, by pipetting up and down a few times. RT-PCR reaction mixture
was amplified using the following cycling parameters: hold at 50°C for 30
min (RT step), hold at 95°C for 15 min (hot start to PCR), then subjected
to 35 cycles of amplification: 94°C for 30 sec, 55°C for 45 sec and
72°C for 1 min and a final incubation at 72°C for 7 min for potyvirus
detection, but hold at 50°C for 30 min (RT step), hold at 95°C for 15
min (hot start to PCR), then subjected to 35 cycles of amplification, 30 sec
at 94°C for denaturation, 30 sec at 54°C for annealing and 60 sec at
72°C for extension, followed by a final hold at 72°C for 10 min for
TuMV detection. For electrophoresis analysis, aliquots 10 μLeach of PCR
amplified DNA (Promega, USA) products were mixed with gel loading buffer. Separation
was done on a 1% agarose gel in 1XTBE buffer (1x = 89 mM Tris, 89 mM borate
and 2 mM EDTA, pH 8.3). DNA was stained with ethidium bromide added to the gel
at a concentration of 0.5 μg mL-1. DNA was visualized on a UV
transilluminator and photographed using DNA documentation gel analysis (model
No. OptiGo 500, Isogen, Holland). DNA 1 kb marker (Promega, country) was used
to determine the size of RT-PCR amplified cDNA products (Sambrook
et al., 1989).
Sequencing of the Coat Protein Gene of Tumv and Data Analysis
The nucleotide sequence of the amplified DNA fragment of expected size (985
bp) of the coat protein gene which included 54 bp of the 3`-end of NIb gene
and 65 bp of the 3`-UTR was determined. The amplified PCR product was purified
using the Wizard PCR clean up kit (Promega, USA). The detrermination of the
nucleotide sequence of the isolated gene of TuMV was carried out in one direction
with the specific complementary primer at King Faisal Specialist Hospital and
Research Center, Biological and Medical Research Department, Riyadh, Kingdom
of Saudi Arabia using AB 3730 xl DNA Analyzer (Applied Biosystem-HITACHI, Japan).
Sequence analysis were performed in triplicates for each sample and the homolog
tree analysis were done using DNAMAN trial version 5.2.10 program (Lynnon BioSoft,
Quebec, Canada). The GenBank accession numbers for the different isolates of
TuMV shown in Table 1 were used for comparison.
||Homology matrix between the Saudi Arabian isolates of TuMV
(lettuce TuMV-L-Sa and radish TuMV-Ra-Sa) and 22 isolates of different host
and geographical origins.
In the repeated host range experiments, mosaic symptoms were observed on the
inoculated radish, lettuce, garden rocket and turnip (Fig. 2a-d)
which were mechanically inoculated with sap from infected plants whereas local
lesions were observed on C. amaranticolor (Fig. 2e).
No symptoms were observed on the rest of the inoculated plants. Also, no symptoms
were observed on the control plants. TuMV was transmitted to both radish and
lettuce by B. brassicae L., in a non persistent manner. Eight out of
the 10 radish seedlings and 7 out of the 10 lettuce seedlings on which aphids
fed on the infected plants were allowed to feed, exhibited mosaic symptoms.
No symptoms were observed on the control plants on which aphids fed on healthy
plants only, were allowed to feed. Although, several aphid vectors for TuMV
were reported to occur in Saudi Arabia (Aldryhim and Khalil,
1996) where some such as M. persicae were more efficient than B.
brassicae, the later was tested because it was the only species encountered
prior to the insect transmission experimentation. The transmission electron
microscope indicated presence of filamentous, flexible, virus particles (Fig.
2f) typical of potyviruses on the negatively stained, carbon coated grids
that were prepared from infected leaf pieces of lettuce and radish using the
leaf dip method. The twenty lettuce samples and the thirty radish samples that
were collected from field grown plants in Riyadh governorate (El-Hayer and Oyayna
fields) were showing conspicuous mosaic symptoms of light and dark green areas
in the leaves. ELISA test of these samples was positive with TuMV antiserum
only and negative with antisera to AMV, CMV, TSWV and LMV that commonly infect
lettuce and radish. Turnip mosaic virus as a potyvirus infecting lettuce and
radish plants was detected separately by RT-PCR using PCPR1/PNIbF1 and PCPR1/PNIbF5
PCR primers. The expected band on the agarose gel after RT-PCR amplification
was about 1.2 and 1 kb, respectively. RT-PCR was, therefore, utilized successfully
in this study to detect a potyvirus in the infected lettuce and radish plant
tissues. Electrophoresis analysis of RT-PCR product showed single amplified
fragments of 1.2 and 1 kb (Fig. 3), (lane 1, 3, 5, 6) respectively.
No amplified fragments of cDNA were obtained from uninfected lettuce leaves
(lane 2, 4).
||Mosaic symptoms of Turnip mosaic virus (TuMV) on inoculated
(a) radish, (b) lettuce, (c) garden rocket, (d) turnip (d) plants and (e)
local lesions on Chenopodium amaranticolor. An electron micrograph
showing filamentous and (f) flexible virus particles of TuMV
To confirm these results, RT-PCR was performed on total RNA extracted from
30 mg infected and uninfected lettuce and radish plants with TuMV isolate using
the SV total RNA Isolation System Kit (Promega, USA). The RNA was reverse transcripted
using reverse transcriptase. The reverse transcription reaction was primed with
the complementary primer specific for TuMV. The resulting cDNA was amplified
by PCR after adding the complementary and homologous primers. RT-PCR amplification
of viral RNA was carried out on the total RNA isolated from infected and uninfected
lettuce and radish plants using specific primer for TuMV-CP Sanchez
et al. (2003) designed to amplify 985 bp of the coat protein gene.
Electrophoresis analysis of RT-PCR product showed a single amplified fragment
of 985 bp. Figure 4 shows the agarose gel electrophoresis
of RT-PCR amplified TuMV-CP cDNA from infected lettuce and radish (lane 1, 2),
respectively. No amplified fragments of cDNA were obtained from healthy lettuce
leaves (lane 3).
The PCR product of TuMV-CP gene which was isolated from lettuce and radish
and sequenced two times in the research center of King Faisal specialist Hospital,
at Riyadh, Saudi Arabia, indicated that their sequences were composed of 878
and 864 nucleotides in length, respectively.
||Different potyviruses detected by RT-PCR and potyvirus degenerate
primers. Total RNA of potyvirus-infected lettuce and radish plants was extracted
and analyzed. The RT primer was PCPR1. The PCR primer pair used to detect
potyvirus infection was PCPR1/PNIbF1 from lettuce and radish Lane 1 and
3 and the size of the RT-PCR fragment was about 1.2 kb and PCPR1/PNIbF5
and the size of the RT-PCR fragment was about 1.0 kb from lettuce and radish
Lane 5 and 6. Lane M represents 1KB DNA Marker. A healthy tissue control
via SV-Total RNA Isolation System kit (lane 2 and 4). RT-PCR products were
analyzed in 1% agarose gel
||Gel electrophoresis on RT-PCR amplification of a fragment
from TuMV genome using specific primer pair designed to amplify 986 bp fragment
of CP gene. Lane M represents 1KB DNA Marker. Lanes 1, 2 were loaded from
different two isolates infected lettuce and radish with TuMV and processed
with the SV-Total RNA isolation system, a healthy tissue control via SV-total
RNA isolation system kit (lane 3)
The CP gene sequence of the TuMV Saudi Arabian isolates of TuMV isolated from
lettuce and radish were, hence, unequal in length. The homology percentages
and the results of the multiple alignments done along with the sequences previously
obtained by GenBank sequence data at the National Center for Biotechnology Information
(NCBI) are shown in Table 1 and Fig. 5,
||The phylogenetic homology tree based on multiple sequence
alignments of the TuMV-L-Sa and TuMV-Ra-Sa isolates compared to previously
The nucleic acid sequence analysis of the lettuce isolate of turnip mosaic
virus designated, TuMV-L-Sa, revealed a range of 85.3 to 90.9% sequence identity
with the isolates obtained from the GenBank. The highest sequence similarity
was found with TuMV JPN 1 isolate isolated from Raphanus sativus, Japan
#AF434724 (90.9%), while the lowest was found with CJ isolate from Chinese
cabbage, South Korea No. AF103788 (85.3%). However, sequence analysis of
the nucleic acid of the radish isolate, TuMV-Ra-Sa, revealed a range of 87.7
to 94.1% sequence identity with the GenBank isolates. The highest sequence similarity
was found with TuMV GAT strain isolated from Brassica juncea, South Korea
No. AF103787 (94.1%) whereas the lowest was found with PV377 isolate from Alliaria
afficinalis, Italy No. AF434726 (87.7%). A phylogenetic tree illustrating
homologous relationships based on multiple alignments of CP nucleotide sequences
of 22 TuMV isolates and the Saudi isolates of TuMV (lettuce isolate, TuMV-L-Sa
and radish isolate, TuMV-Ra-Sa) is shown in Fig. 5.
Turnip mosaic virus detected in vegetables in this study as well as in a earlier
study (Al-Saleh et al., 2008) has been reported
to cause diseases in vegetables and other crops elsewhere in the world (Zdenka,
1980; Stavolone et al., 1998; Hughes
et al., 2002) and is also being recently reported to continue inducing
disease (Robertson and Ianson, 2005; Pallett
et al., 2008). The virus has many strains which are variable in their
pathogenicity, antigenicity and the plant species they infect (Stavolone
et al., 1998; Pallett et al., 2008;
Zdenka, 1980). This could probably explain the somewhat
narrower host range of the TuMV isolate in this investigation which infected
relatively a few number of plants, different from the wide host range isolates
reported in earlier studies (Chen et al., 2003;
Edwardson and Christie, 1991; Green
and Deng, 1985). N. glutinosa was also not infected with an isolate
of TuMV used in another investigation (Zdenka, 1980).
One of the possible reasons for the spread of this virus is the aphid species
from which two species were recorded in this study, B. brassicae and
M. persicae, in addition to the others reported in earlier studies (Aldryhim
and Khalil, 1996) out of the many aphid species reported to transmit this
To develop a similar identification method for the new virus which belongs
to the potyvirus group, local conserved regions in the core domain of the potyvirus
coat protein and in the NIb replicase protein were selected to provide nucleotide
sequences of the construction of degenerate primers for application in a potyvirus
group specific combined assay of RT-PCR. The available potyvirus sequence data
made it possible to develop a method for the identification of potyviruses based
upon the RT-PCR. The sequence between the downstream and upstream primers used
in this study represents a highly conserved region of the coat protein gene
which should be identical in size in every potyvirus (Langeveld
et al., 1991). Three degenerate primers, located at the NIb and CP
gene regions, were designed for potyvirus detection. Using these primer pairs,
1.0-1.2 kb cDNA fragments of the 3-terminal region of 6 potyviruses were successfully
amplified from infected plant tissues. RT-PCR products were sequenced and found
to be derived from the expected viruses (Hsu et al.,
2005). An RT-PCR based method, which has the potential to detect members
of the genus Potyvirus by using new designed potyvirus degenerate primers, was
developed. Since, the amino acid sequence GNNSGQPSTVVDN is highly conserved
among potyviruses, the primers PNIbF1 and PNIbF5 that are derived from the 5`
and `3 region of this coding sequence should amplify any potyvirus. However,
more experiments are needed to confirm this possibility. Although, similar methods
have been described previously by Langeveld et al.
(1991), Gibbs and Mackenzie (1997) and Chen
et al. (2001), the procedure used in this study was different since,
two primer pairs were used to avoid false negative results. Accordingly, a potyvirus
should be amplified from the RT-PCR method resulting in a product of 1.0-1.2
kb, depending on the size of the `5-terminus of the CP gene and also the `3-terminus
of the NIb gene, but no specific amplification was observed with cucumovirus,
carmovirus, potexvirus and tobamovirus. Furthermore, using the PCPR1 potyvirus
degenerate primer, rather than a dT primer, as the reverse primer for the RT-PCR
can avoid the potential problem of interaction with plant poly(A)+ mRNAs. Therefore,
this RT-PCR method can be used as a rapid detection method for potyviruses (Hsu
et al., 2005).
The CP gene sequences of the Saudi Arabian isolates of TuMV from lettuce and
radish were composed of 878 and 864 nucleotides in length, respectively. The
length of nucleotide sequence for TuMV isolates reported from different plant
species, so far, ranges between 864 and 867. These differences in lengths are
probably inherent since they were encountered in isolates infecting the same
or different plant species in the same or distant geographical locations (Table
1) (Zhuang et al., 2006; Ha
et al., 2008; Shi et al., 2008). However,
the length of the nucleotide sequence of the lettuce isolate of TuMV is reported
for the first time in this study and accounted for 878 nucleotides.
Based on symptoms expression, serology, molecular detection and the nucleotide
sequences of CP genes, the agents that infected lettuce and radish were identified
as isolates of TuMV and designated (TuMV-L-Sa and TuMV-Ra-Sa). These findings
confirmed the wide spread of this virus in cruciferous crops reported by Edwardson
and Christie (1991). It is also reported to be naturally occurring in ornamental
crops, lisianthus (Chao et al., 2000) and statice
(Powell and Lindquist, 1992). To our knowledge, this is
the first record that TuMV infects lettuce plants. TuMV may have been infecting
lettuce for many years without being detected. Present results suggest that
the ability to infect lettuce is a common characteristic among TuMV strains.
This is further supported by our observations that TuMV-infected plants were
frequently found in lettuce fields adjacent to turnip or radish. Thus, the virus
is disseminated from TuMV-infected cruciferous plants to lettuce and radish
plants by aphids. This can happen in any geographical areas where both lettuce
and cruciferous crops are grown side by side. TuMV induces severe systemic symptoms
on lettuce and radish. Its infection will jeopardize lettuce and radish production.
In this study, we have been able to identify and characterize TuMV from two plant species, which was the main objective of this study. The significance of this investigation stems from the fact that this is the first encounter of this virus on these two crops in Saudi Arabia. Although, the two TuMV isolates from radish and lettuce are from the same region and infected the same host range, they were found not to be closely related to each other (Fig. 5). It is worth to mention that the radish isolate was also found to be more closely related to the GenBank isolates used in this study than the lettuce isolate. These results are also of great significance since, they will help in the management of this disease.
We thank the Agriculture Research Center at the College of Food and Agricultural Sciences for the financial support of this research project (designated PLP 41) and the help of Dr. Ahmed Ali Al-Qahtani at the Biological and Medical Research Department, King Faisal Specialist Hospital and Research Center, in providing the sequencing facility, is greatly appreciated.
AL-Saleh, M.A, I.M. Al-Shahwan, M.A. Amer and O.A. Abdalla, 2009. Serological and molecular detection of a turnip mosaic virus isolate infecting lettuce in the Kingdom of Saudi Arabia and determination of its coat protein gene nucleotide sequence. Proceedings of the 1st International Conference on Biotechnology.
AL-Saleh, M.A, I.M. Al-Shahwan, O.A. Abdalla and M.A. Amer, 2008. Identification and partial nucleotide sequence turnip mosaic potyvirus on garden rocket (Eruca sativa) in Saudi Arabia. Proceedings of the 5th Scientific conference of the Yemeni Biological Society, Al-Mokala, November 22-23, Yemen.
Aldryhim, Y. and A.F. Khalil, 1996. Aphididae of Saudi Arabia. Fauna Saudi Arabia, 15: 161-196.
Barnett, O.W., G. Adam, A. Brunt, J. Dijkstra and W.G. Dougherty et al., 1995. Family potyviridae. Proceedings of the Sixth Report of the International Committee on Taxonomy of Viruses, 1995, Springer-Verlag, Wien, New York,-pp: 348.
Chao, C.H., C.C. Chen, C.A. Chang and C.C. Chen, 2000. Identification of a turnip mosaic virus isolate causing systemic yellow spotting on lisianthus. Plant Pathol. Bull., 9: 115-122.
Chen, C.C., C.H. Chao, S.D. Yeh, H.T. Tsai and C.A. Chang, 2003. Identification of turnip mosaic virus isolates causing yellow stripe and spot on calla lily. Plant Dis., 87: 901-905.
CrossRef | Direct Link |
Chen, J., J. Chen and M.J. Adams, 2001. A universal PCR primer to detect members of the Potyviridae and its use to examine the taxonomic status of several members of the family. Arch. Virol., 146: 757-766.
CrossRef | Direct Link |
Clark, M.F. and A.N. Adams, 1977. Characteristics of the microplate method of enzyme-linked immunosorbent assay for the detection of plant viruses. J. Gen. Virol., 34: 475-483.
CrossRef | PubMed | Direct Link |
Edwardson, J.R. and R.G. Christie, 1991. The potyvirus group. University of Florida, Florida Agricultural Experiment Station Monograph Series No. 16. pp: 1244.
Gardner, M.W. and J.B. Kendrick, 1921. Turnip mosaic. J. Agric. Res., 22: 123-124.
Gibbs, A. and A. Mackenzie, 1997. A primer pair for amplifying part of the genome of all potyvirids by RT-PCR. J. Virol. Methods, 63: 9-16.
PubMed | Direct Link |
Green, S.K. and T.C. Deng, 1985. Turnip mosaic virus strains in cruciferous hosts in Taiwan. Plant Dis., 69: 28-31.
Direct Link |
Ha, C., P. Revill, R.M. Harding, M. Vu and J.L. Dale, 2008. Identification and sequence analysis of potyviruses infecting crops in Vietnam. Arch. Virol., 153: 45-60.
Direct Link |
Hill, S.A., 1984. Methods in Plant Virology. 1st Edn., Blackwell Scientific Publications, Oxiford, London, Edinburgh, pp: 167.
Hsu, Y.C., T.J. Yeh and Y.C. Change, 2005. A new combination of RT-PCR and reverse dot blot hybridization for rapid detection and identification of potyviruses. J. Virol. Methods, 128: 54-60.
CrossRef | Direct Link |
Hughes, S.L., S.K. Green, D.J. Lydiate and J.A. Walsh, 2002. Resistance to turnip mosaic virus in Brassica rapa and B. napus and the analysis of genetic inheritance in selected lines. Plant Pathol., 51: 567-573.
Direct Link |
Langeveld, S.A., I.M. Dore, I. Memelink, A.R.L.M. Derks, C.I.M. Van der Vlugt, C.J. Asjes and J.E. Bol, 1991. Identification of potyviruses using polymerase chain reaction with degenerate primers. J. Gen. Virol., 72: 1531-1541.
Direct Link |
Lesemann, D. and H.J. Vetten, 1985. The occurrence of tobacco rattle and turnip mosaic viruses in Orchis spp. and of an unidentified potyvirus in Cypripedium calceolus. Acta Hortic., 164: 45-54.
Pallett, D.W., J.I. Cooper, H. Wang, J. Reeves and Z. Luo et al., 2008. Variation in the pathogenicity of two turnip mosaic virus isolates in wild UK Brassica rapa provenances. Plant Pathol., 57: 401-407.
CrossRef | Direct Link |
Powell, C.C. and R.K. Lindquist, 1992. Viruses: Ball Pest and Disease Manual. 2nd Edn., Ball Publishing, Geneva, IL, pp: 133-142.
Provvidenti, R., 1996. Turnip Mosaic Potyvirus. In: Viruses of Plants, Brunt, A.A., K. Crabtree, M.J. Dallwitz, A.J. Gibbs and L. Watson (Eds.). CAB International, Wallingford, UK., pp: 1340-1343.
Riechmann, J.L., S. Lain and J.A. Garcia, 1992. Highlights and prospects of potyvirus molecular biology. J. Gen. Virol., 73: 1-16.
Direct Link |
Robertson, N.L. and D.C. Ianson, 2005. First report of turnip mosaic virus in Rhubarb in Alaska. Plant Dis., 89: 430-430.
Direct Link |
Rybicki, E.P. and F.L. Hughes, 1990. Detection and typing of maize streak virus and other distantly related geminiviruses of grasses by polymerase chain reaction amplification of a conserved viral sequence. J. Gen. Virol., 71: 2519-2526.
CrossRef | Direct Link |
Sambrook, J., E.F. Fritsch and T.A. Maniatis, 1989. Molecular Cloning: A Laboratory Manual. 2nd Edn., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, USA., ISBN-13: 9780879695774, Pages: 397.
Sanchez, F., X. Wang, C.E. Jenner, J.A. Walsh and F. Ponz, 2003. Strains of turnip mosaic potyvirus as defined by the molecular analysis of the coat protein gene of the virus. Virus Res., 94: 33-43.
Direct Link |
Schultz, E.S., 1921. A transmissible mosaic disease of Chinese cabbage, mustard and turnip. J. Agric. Res., 22: 173-177.
Shattuck, V.I., 1992. The biology, epidemiology and control of turnip mosaic virus. Hortic. Rev., 14: 199-238.
Shi, M., H.Y. Li, J. Schubert and X. Zhou, 2008. Sequence analysis of cp and Hc-pro genes of turnip mosaic virus isolates from china. Acta Virol., 52: 59-62.
Direct Link |
Shukla, D.D., C.W. Ward and A.A. Brunt, 1994. The Potyviridae. 1st Edn., CAB International, Wallingford, UK., Pages: 516.
Stavolone, L., D. Alioto, A. Ragozzino and J.F. Laliberte, 1998. Variability among Turnip mosaic potyvirus isolates. Phytopathology, 88: 1200-1204.
Direct Link |
Tomlinson, J.A. and C.M. Ward, 1978. The reactions of swede (Brassica napus) to infection by turnip mosaic virus. Ann. Applied Biol., 89: 61-69.
CrossRef | Direct Link |
Tomlinson, J.A., 1987. Epidemiology and control of virus diseases of vegetables. Ann. Applied Biol., 110: 661-681.
CrossRef | Direct Link |
Walsh, J.A. and C.E. Jenner, 2002. Turnip mosaic virus and the quest for durable resistance. Mol. Plant Pathol., 3: 289-300.
Direct Link |
Walsh, J.A. and J.A. Tomlinson, 1985. Viruses infecting winter oilseed rape (Brassica napus ssp. oleifera). Ann. Applied Biol., 107: 485-495.
Direct Link |
Zdenka, P., 1980. Host range and symptom differences between isolates of turnip mosaic virus obtained from Sisymbrium loeselii. Biol. Plant., 22: 341-347.
Zhuang, M., X.W. Wang and Y.S. Li, 2006. Cloning and sequence analysis of turnip mosaic virus coat protein gene. Zhongguo Shu Cai, 3: 6-8.