Basic HTML Version
Genomics and Applied Biology, 2011, Vol.2 No.2
http://gab.sophiapublisher.com
- 10 -
Research Article Open Access
Differential Expression of
P19
, Cytochrome Oxidase and ALY-family Genes in
Resistant and Susceptible Tomato Cultivars (
Solanum lycopersicum
) Inoculated
with
Tomato Bushy Stunt Virus
Elsayed E. Hafez
1
Mahmoud F.M. Moustafa
2
1. Mubarak City for Scientific Research and Technology Applications, Arid Lands and development Research Institute, Borg El Arab, 21934, Alexandria, Egyp
2. Botany Department, Faculty of Science, South Valley University, Egypt/King Khalid University, Saudi Arabia
Corresponding author, elsayed_hafez@yahoo.com;
Authors
Genomics and Applied Biology 2011, Vol.2 No.2 doi: 10.5376/gab.2011.02.0002
Received: 28 Jan., 2011
Accepted: 01 Mar., 2011
Published: 22 Apr., 2011
This is an Open Access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Hafez E.E., and Moustafa M.F.M., 2011, Differential Expression of
P19
, Cytochrome Oxidase and ALY-family Genes in Resistant and Susceptible Tomato
Cultivars (
Solanum lycopersicum
) Inoculated with
Tomato Bushy Stunt Virus
, Genomics and Applied Biology, 2011, Vol.2, No.2 (doi: 10.5376/
gab.2011.02.0002)
Abstract
Tomato cultivars (TY20, TY70/84 and TY70/70) were mechanically inoculated with purified virus preparations of
Tomato bushy stunt virus
(TBSV). Inoculated plant tissues were collected after one day, one week and two weeks post-inoculation,
respectively. The
P19
gene was amplified using specific RT-PCR from the three examined tomato cultivars. Our main result is that
the expression of the
P19
gene was high in both TY70/84 and TY70/70, but it was very low in case of TY20 tomato cultivars.
Messenger RNA of the inoculated and healthy plants was scanned using the differential display technique to discover the up- and
down-regulated genes induced or suppressed in the infected plants. Three down-regulated and four up-regulated genes were observed.
Sequence analysis revealed that the 400 bp up-regulated genes amplified from cultivars TY70/84 and TY70/70 were cytochrome
oxidase genes. Expression of these genes was highest in cultivar TY70/84, followed by cultivar TY70/70; it was considerably low in
cultivar TY20 and the control plants. The other four up-regulated genes belonged to the ALY gene family. We conclude that the
expression of P19, cytochrome oxidase, and ALY family genes were highly expressed in inoculated plants with TBSV compared to
the control plants, which suggest that these genes are members of the plant innate immune system.
Keywords
Differential expression; Tomato (
Solanum lycopersicum
);
Tomato bushy stunt virus
(TBSV);
P19
gene; Cytochrome
oxidase; Aly-family genes
Background
Plant immune system able to develop resistance to
pathogens is a phenomenon that has not been well-
characterized. Leisner et al (1993) characterized a form of
developmental resistance in Arabidopsis to
Cauliflower
mosaic virus
(CaMV) that was related to sink-source
relationships. Cole et al (2004) reported that the
temporal induction of plant defenses in ‘Columbia’
may provide a new tool for studying plant defenses
in Nicotiana. Martelli and his colleagues (1988)
postulated that
Tomato bushy stunt virus
(TBSV) is a
suitable virus for studies of symptom determinants
because of its broad experimental host range and the
variety of symptoms it induces on different hosts,
especially tomato plants. TBSV is icosahedral virus
containing a single copy of a positive sense single-
stranded RNA genome of about 4800 nucleotides
(Hearne et al., 1990). The genome of TBSV contains
encoded five major open reading frames. The 5'
proximal half of the genomic RNA functions as an
mRNA for translation of a 33 kD protein (p33) and a
read through product of 92 kD (p92), both of which are
required for replication (Scholthof et al., 1995). The
41 kD coat protein gene is located farther downstream,
and translation of this protein occurs from a
subgenomic mRNA (Hillman et al., 1989). Additionally,
two small nested genes located near the 3' terminus of
the genome are expressed via a second subgenomic
mRNA that directs synthesis of a 22 kD protein (p22)
and a 19 kD protein (p19) (Hayes et al., 1988).
Studies with other tombusviruses indicate that the p22
analog is necessary for systemic movement; this gene
influences symptom severity (Rochon, 1991; Dalmay
et al., 1993). Another study revealed that p22 of TBSV
is required for cell-to-cell movement; whereas P19 is