Phytoparasitica (2002) 30 (3) - Transformation of tobacco with ...

F. Akad, Ema Teverovsky, B. Kirshner, D. Gidoni, Y. Elad, H. Czosnek and G. Loebenstein (2002)
Transformation of tobacco with cDNA that codes for the inhibitor of virus replication (IVR) causes partial resistance to TMV and to some fungi: possible action through the ABA biosynthesis pathway
Phytoparasitica 30 (3)
The 23rd Congress of the Israeli Phytopathological Society - February 11-12, 2002
Abstract: An expression cDNA library was prepared from induced-resistant Nicotiana tabacum cv. Samsun NN and screened with polyclonal antibody raised against the IVR protein. A 1016 bp clone (named NC 330) was isolated. The predicted NC330 protein had 199 amino acid, with a molecular weight of 21.6 kDa. This protein contained leucine-rich repeats, nucleotide binding site motifs, as well as six phosphorylation, two myristilation, and one glycosylation site, all of which are found in the R-gene family. The IVR-like gene was present in the genome of both resistant and susceptible tobacco, at least with one copy, but differed in its polymorphism in agarose gel. NC330 transcripts were observed in induced-resistant tobacco tissue but not in un-induced or susceptible tobacco. The NC330 protein over-expressed in Escherichia coli reduced TMV replication in tobacco Samsun nn leaf disk assay. The NC330 cDNA was inserted into the binary vector pBJFLO and used to transform susceptible tobacco Samsun nn. Seventy-four regenerated transgenic plants were obtained; two of them were highly resistant to TMV. At the S₁ generation, 5 of the 92 transgenic plants were resistant; at the S₂ generation, 7 of the 117 plants showed high levels of resistance to TMV in leaf disk assay. When the whole plant was inoculated with TMV, a delay of 12–14 days in symptom appearance was observed. At the S₃ generation, PCR test for presence of NPTII and NC330 revealed that less than one third of the plants were transgenic, the majority of which showed high resistance to TMV. NC330 transcripts were detected in all the transgenic plants, including those that did not show TMV resistance. Compared to non-transgenic susceptible plants, germination of transgenic Samsun nn seeds in the dark or at high temperatures was inhibited. Abscisic acid (ABA) concentration in transgenic tobacco seeds or seedlings was higher than in non-transgenic controls. In addition, roots of transgenic tobacco seedlings were significantly longer than those of the non-transgenic controls. Seeds of the transgenic plants were darker than those of the control plants. Transgenic seedlings expressing the NC330 cDNA were resistant to Alternaria alternata and Botrytis cinerea. The involvement of ABA in resistance to viruses or fungi, and the possibility of post transcription silencing, were discussed.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Gad Loebenstein, Yigal Elad, Henryk Czosnek, Fouad Akad

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.
	Botrytis cinerea	Tobacco (Nicotiana tabacum)
	Alternaria alternata	Tobacco (Nicotiana tabacum)
	Tobacco mosaic virus	Tobacco (Nicotiana tabacum)