1. NRG1, a CC-NB-LRR protein, together with N, a TIR-NB-LRR protein, mediates resistance against tobacco mosaic virus.
- Author
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Peart JR, Mestre P, Lu R, Malcuit I, and Baulcombe DC
- Subjects
- Amino Acid Sequence, Cloning, Molecular, DNA, Complementary genetics, Gene Components, Gene Library, Gene Silencing, Molecular Sequence Data, Nucleic Acid Amplification Techniques, Plant Proteins immunology, Plants, Genetically Modified, Nicotiana virology, Immunity, Innate immunology, Plant Diseases virology, Plant Proteins genetics, Signal Transduction immunology, Nicotiana immunology, Tobacco Mosaic Virus
- Abstract
In animals and plants, innate immunity is regulated by nucleotide binding domain and leucine-rich repeat (NB-LRR) proteins that mediate pathogen recognition and that activate host-cell defense responses. Plant NB-LRR proteins, referred to as R proteins, have amino-terminal domains that contain a coiled coil (CC) or that share similarity with animal Toll and interleukin 1 receptors (TIR). To investigate R protein function, we are using the TIR-NB-LRR protein N that mediates resistance against tobacco mosaic virus (TMV) through recognition of the TMV p50 protein. Here, we describe N requirement gene 1 (NRG1), a novel N-resistance component that was identified by a virus-induced gene silencing (VIGS) screen of a cDNA library. Surprisingly, NRG1 encodes an NB-LRR type R protein that, in contrast to N, contains a CC rather than a TIR domain. Our findings support emerging evidence that many disease-resistance pathways each recruit more than a single NB-LRR protein. The results also indicate that, in addition to the previously recognized role in elicitor recognition, NB-LRR proteins may also function in downstream signaling pathways.
- Published
- 2005
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