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RNA interference-based resistance in transgenic tomato plants against Tomato yellow leaf curl virus-Oman (TYLCV-OM) and its associated betasatellite.

Ammara Ue, Mansoor S, Saeed M, Amin I, Briddon RW, Al-Sadi AM - Virol. J. (2015)

Bottom Line: Unusually, TYLCV infections in Oman are sometimes associated with a betasatellite (Tomato leaf curl betasatellite [ToLCB]; a symptom modulating satellite).These results show that RNAi can be used to develop resistance against geminiviruses in tomato.Also, the betasatellite may compromise resistance, increasing the proportion of plants which ultimately show symptoms.

View Article: PubMed Central - PubMed

Affiliation: Department of Crop Sciences, College of Agriculture and Marine Sciences, Sultan Qaboos University, P.O. Box-34, 123, Al-Khod, Oman. ammarajawad@gmail.com.

ABSTRACT

Background: Tomato yellow leaf curl virus (TYLCV), a monopartite begomovirus (family Geminiviridae) is responsible for heavy yield losses for tomato production around the globe. In Oman at least five distinct begomoviruses cause disease in tomato, including TYLCV. Unusually, TYLCV infections in Oman are sometimes associated with a betasatellite (Tomato leaf curl betasatellite [ToLCB]; a symptom modulating satellite). RNA interference (RNAi) can be used to develop resistance against begomoviruses at either the transcriptional or post-transcriptional levels.

Results: A hairpin RNAi (hpRNAi) construct to express double-stranded RNA homologous to sequences of the intergenic region, coat protein gene, V2 gene and replication-associated gene of Tomato yellow leaf curl virus-Oman (TYLCV-OM) was produced. Initially, transient expression of the hpRNAi construct at the site of virus inoculation was shown to reduce the number of plants developing symptoms when inoculated with either TYLCV-OM or TYLCV-OM with ToLCB-OM to Nicotiana benthamiana or tomato. Solanum lycopersicum L. cv. Pusa Ruby was transformed with the hpRNAi construct and nine confirmed transgenic lines were obtained and challenged with TYLCV-OM and ToLCB-OM by Agrobacterium-mediated inoculation. For all but one line, for which all plants remained symptomless, inoculation with TYLCV-OM led to a proportion (≤25%) of tomato plants developing symptoms of infection. For inoculation with TYLCV-OM and ToLCB-OM all lines showed a proportion of plants (≤45%) symptomatic. However, for all infected transgenic plants the symptoms were milder and virus titre in plants was lower than in infected non-transgenic tomato plants.

Conclusions: These results show that RNAi can be used to develop resistance against geminiviruses in tomato. The resistance in this case is not immunity but does reduce the severity of infections and virus titer. Also, the betasatellite may compromise resistance, increasing the proportion of plants which ultimately show symptoms.

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Related in: MedlinePlus

Analysis of the resistance imparted by the hpRNAi construct in transgenic tomato to infection by TYLCV-OM/ToLCB-OM. Plants of transgenic tomato cv. Pusa Ruby lines 11, 12, 13, 18, 21, 23, 41, 51 and 52 inoculated with TYLCV-OM/ToLCB-OM (A to I). A TYLCV-OM/ToLCB-OM inoculated wild-type Pusa Ruby plant is shown for comparison (J). Photographs were taken at 60 dpi.
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Fig3: Analysis of the resistance imparted by the hpRNAi construct in transgenic tomato to infection by TYLCV-OM/ToLCB-OM. Plants of transgenic tomato cv. Pusa Ruby lines 11, 12, 13, 18, 21, 23, 41, 51 and 52 inoculated with TYLCV-OM/ToLCB-OM (A to I). A TYLCV-OM/ToLCB-OM inoculated wild-type Pusa Ruby plant is shown for comparison (J). Photographs were taken at 60 dpi.

Mentions: All non-transgenic wild type S. lycopersicum cv. Pusa Ruby plants inoculated with TYLCV-OM (Figure 2 panel J) and TYLCV-OM/ToLCB-OM (Figure 3 panel J) developed severe yellowing, leaf curling and a reduced leaflet size, symptoms typical of this virus, by 30 dpi (Table 4). Such plants ceased to grow, failing to flower and produce fruit. Plants inoculated with TYLCV-OM/ToLCB-OM exhibited more severe symptoms than plants inoculated with only the virus, with significantly smaller leaflets.Figure 2


RNA interference-based resistance in transgenic tomato plants against Tomato yellow leaf curl virus-Oman (TYLCV-OM) and its associated betasatellite.

Ammara Ue, Mansoor S, Saeed M, Amin I, Briddon RW, Al-Sadi AM - Virol. J. (2015)

Analysis of the resistance imparted by the hpRNAi construct in transgenic tomato to infection by TYLCV-OM/ToLCB-OM. Plants of transgenic tomato cv. Pusa Ruby lines 11, 12, 13, 18, 21, 23, 41, 51 and 52 inoculated with TYLCV-OM/ToLCB-OM (A to I). A TYLCV-OM/ToLCB-OM inoculated wild-type Pusa Ruby plant is shown for comparison (J). Photographs were taken at 60 dpi.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4359554&req=5

Fig3: Analysis of the resistance imparted by the hpRNAi construct in transgenic tomato to infection by TYLCV-OM/ToLCB-OM. Plants of transgenic tomato cv. Pusa Ruby lines 11, 12, 13, 18, 21, 23, 41, 51 and 52 inoculated with TYLCV-OM/ToLCB-OM (A to I). A TYLCV-OM/ToLCB-OM inoculated wild-type Pusa Ruby plant is shown for comparison (J). Photographs were taken at 60 dpi.
Mentions: All non-transgenic wild type S. lycopersicum cv. Pusa Ruby plants inoculated with TYLCV-OM (Figure 2 panel J) and TYLCV-OM/ToLCB-OM (Figure 3 panel J) developed severe yellowing, leaf curling and a reduced leaflet size, symptoms typical of this virus, by 30 dpi (Table 4). Such plants ceased to grow, failing to flower and produce fruit. Plants inoculated with TYLCV-OM/ToLCB-OM exhibited more severe symptoms than plants inoculated with only the virus, with significantly smaller leaflets.Figure 2

Bottom Line: Unusually, TYLCV infections in Oman are sometimes associated with a betasatellite (Tomato leaf curl betasatellite [ToLCB]; a symptom modulating satellite).These results show that RNAi can be used to develop resistance against geminiviruses in tomato.Also, the betasatellite may compromise resistance, increasing the proportion of plants which ultimately show symptoms.

View Article: PubMed Central - PubMed

Affiliation: Department of Crop Sciences, College of Agriculture and Marine Sciences, Sultan Qaboos University, P.O. Box-34, 123, Al-Khod, Oman. ammarajawad@gmail.com.

ABSTRACT

Background: Tomato yellow leaf curl virus (TYLCV), a monopartite begomovirus (family Geminiviridae) is responsible for heavy yield losses for tomato production around the globe. In Oman at least five distinct begomoviruses cause disease in tomato, including TYLCV. Unusually, TYLCV infections in Oman are sometimes associated with a betasatellite (Tomato leaf curl betasatellite [ToLCB]; a symptom modulating satellite). RNA interference (RNAi) can be used to develop resistance against begomoviruses at either the transcriptional or post-transcriptional levels.

Results: A hairpin RNAi (hpRNAi) construct to express double-stranded RNA homologous to sequences of the intergenic region, coat protein gene, V2 gene and replication-associated gene of Tomato yellow leaf curl virus-Oman (TYLCV-OM) was produced. Initially, transient expression of the hpRNAi construct at the site of virus inoculation was shown to reduce the number of plants developing symptoms when inoculated with either TYLCV-OM or TYLCV-OM with ToLCB-OM to Nicotiana benthamiana or tomato. Solanum lycopersicum L. cv. Pusa Ruby was transformed with the hpRNAi construct and nine confirmed transgenic lines were obtained and challenged with TYLCV-OM and ToLCB-OM by Agrobacterium-mediated inoculation. For all but one line, for which all plants remained symptomless, inoculation with TYLCV-OM led to a proportion (≤25%) of tomato plants developing symptoms of infection. For inoculation with TYLCV-OM and ToLCB-OM all lines showed a proportion of plants (≤45%) symptomatic. However, for all infected transgenic plants the symptoms were milder and virus titre in plants was lower than in infected non-transgenic tomato plants.

Conclusions: These results show that RNAi can be used to develop resistance against geminiviruses in tomato. The resistance in this case is not immunity but does reduce the severity of infections and virus titer. Also, the betasatellite may compromise resistance, increasing the proportion of plants which ultimately show symptoms.

Show MeSH
Related in: MedlinePlus