TY - JOUR
T1 - Tobacco transgenic for the flax rust resistance gene L expresses allele-specific activation of defense responses
AU - Frost, Donna
AU - Way, Heather
AU - Howles, Paul
AU - Luck, Joanne
AU - Manners, John
AU - Hardham, Adrienne
AU - Finnegan, Jean
AU - Ellis, Jeff
PY - 2004/2
Y1 - 2004/2
N2 - Tobacco was transformed with three different alleles (L2, L6, and L10) of the flax rust resistance gene L, a member of the toll interleukin-1 receptor, nucleotide-binding site, leucine-rich repeat (TIR-NBS-LRR) class of plant disease resistance genes. L6 transgenics had a stunted phenotype, expressed several defense response genes constitutively, and had increased resistance to the fungus Cercospora nicotianae and the oomycete Phytophthora parasitica pv. nicotianae. L2 and L10 transgenics, with one exception for L10, did not express these phenotypes, indicating that the activation of tobacco defense responses is L6 allele-specific. The phenotype of the exceptional L10 transgenic plant was associated with the presence of a truncated L10 gene resulting from an aberrant T-DNA integration. The truncated gene consisted of the promoter, the complete TIR region, and 39 codons of the NBS domain fused inframe to a tobacco retrotransposon-like sequence. A similar truncated L10 gene, constructed in vitro, was transiently expressed in tobacco leaves and gave rise to a strong localized necrotic reaction. Together, these results suggest that defense signaling properties of resistance genes can be expressed in an allele-specific and pathogen-independent manner when transferred between plant genera.
AB - Tobacco was transformed with three different alleles (L2, L6, and L10) of the flax rust resistance gene L, a member of the toll interleukin-1 receptor, nucleotide-binding site, leucine-rich repeat (TIR-NBS-LRR) class of plant disease resistance genes. L6 transgenics had a stunted phenotype, expressed several defense response genes constitutively, and had increased resistance to the fungus Cercospora nicotianae and the oomycete Phytophthora parasitica pv. nicotianae. L2 and L10 transgenics, with one exception for L10, did not express these phenotypes, indicating that the activation of tobacco defense responses is L6 allele-specific. The phenotype of the exceptional L10 transgenic plant was associated with the presence of a truncated L10 gene resulting from an aberrant T-DNA integration. The truncated gene consisted of the promoter, the complete TIR region, and 39 codons of the NBS domain fused inframe to a tobacco retrotransposon-like sequence. A similar truncated L10 gene, constructed in vitro, was transiently expressed in tobacco leaves and gave rise to a strong localized necrotic reaction. Together, these results suggest that defense signaling properties of resistance genes can be expressed in an allele-specific and pathogen-independent manner when transferred between plant genera.
KW - NBS-LRR resistance genes
KW - Plant defense
UR - http://www.scopus.com/inward/record.url?scp=1642311105&partnerID=8YFLogxK
U2 - 10.1094/MPMI.2004.17.2.224
DO - 10.1094/MPMI.2004.17.2.224
M3 - Article
SN - 0894-0282
VL - 17
SP - 224
EP - 232
JO - Molecular Plant-Microbe Interactions
JF - Molecular Plant-Microbe Interactions
IS - 2
ER -