天美传媒

Abstract

The Tomato bushy stunt virus (TBSV) is tombusvirus and it has the P19 gene which considered a viral protein that are known to interfere with host defense mechanism. P19 referred to as RNA silencing gene, that targets foreign (virus and retrotransposon) RNAs in a sequence specific manner for degradation. Tomato Lycopersicum esculentum L cultivars; Elisa, Super Strain-B (Super) and GS were inoculated with the Tomato Bushy Stunt Virus (TBSVEgh). The P19 gene sequence was determined from both pure preparation and in inoculated tomato cultivars. Amplicone with molecular size of 850 bp was amplified and the sequence of the viral P19 gene showed similarity with P19 gene of western United States TBSV with 98% identity. On the other hand, the Tomato P19 gene showed 88% identity with the same virus isolate. Studying the up- and down- regulated genes in the three examined cultivars was performed using differential display polymerase chain reaction (DD-PCR). A large number of up- regulated bands and high expression of Actin genes were observed in inoculated plants. The expression of plant defense genes was higher in L. esculentum Mill Elisa cultivar than cultivar G.S. Results indicated that some suspected defense genes, against TBSV Egh, are de novo genes.

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