Virus resistance obtained in transgenic tobacco and rice by RNA interference using promoters with distinct activity

Abstract

To induce virus resistance in tobacco and rice we constructed hairpin RNA expression system harbouring inverted repeat fragments of coat protein cDNA of Potato virus Y (PVY) or Rice stripe virus (RSV). These structures were driven by three promoters [cauliflower mosaic virus 35S (CaMV 35S), polyubiqutin gene of maize (Ubi), and Pharbitis nil leucine zipper gene (PNZIP)] which have different tissue-specific activity. PVY resistance ratios were 65.18, 24.33 and 83.54% in transgenic tobacco plants harboring p35S-PVY, pUbi-PVY and pPNZIP-PVY. RSV resistance was 16.21, 28.61 and 29.33% in transgenic rice plants harboring p35S-RSV, pUbi-RSV and pPNZIP-RSV. Northern blotting and GUS assay demonstrated that virus resistance levels were related to promoter activity. Therefore, choice of the more effective and tissue-specific promoter to reinforce transcription of hpRNAs will favour the cultivation of highly virusresistant transgenic plants. © 2012 Springer Science+Business Media B.V.