Analyses of the cis-Regulatory Regions Responsible for the Transcriptional Activation of the N Resistance Gene by Tobacco mosaic virus

Although the tobacco N gene, which confers resistance to Tobacco mosaic virus (TMV), is transcriptionally induced by infection with TMV, the regulatory mechanism has not previously been elucidated. We found that a 5'-flanking region of the N gene exhibits TMV-inducible promoter activity and that the region from -290 to -271 includes a cis-acting element in response to infection. The activity required N protein and signal components of N-mediated resistance. These results suggest that transcription of the N gene is positively regulated by N-mediated resistance signalling.