Open AccessVariable leucine‐rich repeats of tomato disease resistance genes Cf‐2 and Cf‐5 determine specificity
Author(s) -
Seear Paul J.,
Dixon Mark S.
Publication year - 2003
Publication title -
molecular plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.945
H-Index - 103
eISSN - 1364-3703
pISSN - 1464-6722
DOI - 10.1046/j.1364-3703.2003.00162.x
Subject(s) - biology , gene , leucine rich repeat , genetics , intergenic region , plant disease resistance , chimeric gene , mutant , cladosporium , r gene , genome , gene expression , penicillium
SUMMARY The tomato Cf‐2 and Cf‐5 genes confer race specific resistance to infection by the leaf mould pathogen Cladosporium fulvum . The encoded proteins induce a defence response upon recognition of the fungal Avr2 and Avr5 determinants, respectively. Each resistance protein is comprised largely of leucine‐rich repeats (LRRs) and the specificity of recognition is thought to occur through a particular domain. We have investigated this further using domain swaps between Cf‐2 and Cf‐5. Engineered chimeric genes containing portions of Cf‐2 and Cf‐5 were expressed and shown to be functional. The results clearly show that the specificity for the particular avirulence determinant is restricted to a region of each gene that encodes a subset of LRRs containing the highest level of intergenic variability. In addition, two non‐functional mutants of Cf‐5 were characterized and their significance discussed.