Archives of Virology (2015) 160, 2727-2739

Diana Leibman, Shanmugam Prakash, Dalia Wolf, Aaron Zelcer, Ghandi Anfoka, Sabrina Haviv, Marina Brumin, Victor Gaba, Tzahi Arazi, Moshe Lapidot and Amit Gal-On (2015)
Immunity to Tomato yellow leaf curl virus in transgenic tomato is associated with accumulation of transgene small RNA
Archives of Virology 160 (11), 2727-2739
Abstract: Gene silencing is a natural defense response of plants against invading RNA and DNA viruses. The RNA post-transcriptional silencing system has been commonly utilized to generate transgenic crop plants that are "immune" to plant virus infection. Here, we applied this approach against the devastating DNA virus tomato yellow leaf curl virus (TYLCV) in its host tomato (Solanum lycopersicum L.). To generate broad resistance to a number of different TYLCV viruses, three conserved sequences (the intergenic region [NCR], V1-V2 and C1-C2 genes) from the genome of the severe virus (TYLCV) were synthesized as a single insert and cloned into a hairpin configuration in a binary vector, which was used to transform TYLCV-susceptible tomato plants. Eight of 28 independent transgenic tomato lines exhibited immunity to TYLCV-Is and to TYLCV-Mld, but not to tomato yellow leaf curl Sardinia virus, which shares relatively low sequence homology with the transgene. In addition, a marker-free (nptII-deleted) transgenic tomato line was generated for the first time by Agrobacterium-mediated transformation without antibiotic selection, followed by screening of 1180 regenerated shoots by whitefly-mediated TYLCV inoculation. Resistant lines showed a high level of transgene-siRNA (t-siRNA) accumulation (22 % of total small RNA) with dominant sizes of 21 nt (73 %) and 22 nt (22 %). The t-siRNA displayed hot-spot distribution ("peaks") along the transgene, with different distribution patterns than the viral-siRNA peaks observed in TYLCV-infected tomato. A grafting experiment demonstrated the mobility of 0.04 % of the t-siRNA from transgenic rootstock to non-transformed scion, even though scion resistance against TYLCV was not achieved.
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Link to article at publishers website
Database assignments for author(s): Amit Gal-On, Victor Gaba, Ghandi H. Anfoka, Tzahi Arazi, Moshe Lapidot

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Tomato yellow leaf curl virus	Tomato (Solanum lycopersicum)
	Tomato yellow leaf curl Sardinia virus	Tomato (Solanum lycopersicum)