title: The tobacco mosaic virus resistance gene, N.
abstract: Summary In this mini review we discuss recent advances in the understanding of the N gene-mediated resistance to tobacco mosaic virus (TMV). The tobacco N gene belongs to toll-interleukin-1 receptor homology/nucleotide binding/leucine rich repeat (TIR-NB-LRR) class of resistance genes. It encodes two transcripts, N(S) and N(L), by alternative splicing, both of which are required to confer resistance to TMV. The structure-function analysis of the N gene indicates that the TIR, NB and LRR domains are indispensable for its function. The N gene response is elicited by the C-terminal helicase domain of the 126 kDa TMV replicase protein. Tobacco N gene can also confer resistance to TMV in heterologous plants like tomato and Nicotiana benthamiana. Recent studies on N-mediated signalling suggest that EDS1, Rar1 and NPR1 genes play an important role in TMV resistance. Finally, we discuss current status of the N-mediated signal transduction and speculate directions for future work to understand N-TMV interaction.
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, OML 451, Yale University, PO Box 208104, New Haven, CT 06520-8104, USA.
authors.forename: Rajendra
authors.initials: R
authors.lastname: Marathe
authors.forename: Radhamani
authors.initials: R
authors.lastname: Anandalakshmi
authors.forename: Yule
authors.initials: Y
authors.lastname: Liu
authors.forename: S P
authors.initials: SP
authors.lastname: Dinesh-Kumar