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Identification and molecular analysis of candidate genes homologous to HcrVf genes for scab resistance in apple.
- Source :
- Plant Breeding; Feb2009, Vol. 128 Issue 1, p84-91, 8p, 1 Black and White Photograph, 3 Diagrams, 3 Charts
- Publication Year :
- 2009
-
Abstract
- The genetic locus for resistance to apple scab most frequently used in apple breeding is Vf, derived from Malus floribunda 821. For the Vf locus a cluster of four resistance gene paralogs (called as HcrVf genes) encoding receptor-like proteins (RLP) with similarity to the tomato Cf resistance genes is known. Based on published sequences for HcrVf1 and HcrVf2 PCR primers were designed from the domain B and the variable leucine-rich repeat (LRR) C1 subdomain. PCR products with high amino acid identity (85–100%) to HcrVf1 and HcrVf2 were obtained not only from M. floribunda 821 and Vf cultivars but also from other apple scab resistance sources, such as ‘Russian Seedling’ R12740-7A ( Vr resistance) or ‘Antonovka polutorafuntovaya’ ( VA resistance). A series of 13 HcrVf candidate genes have been partly cloned from the PCR fragments spanning N-terminal LRRs 20–30. A considerable number of amino acid exchanges within the solvent-exposed xxLxLxx structural motives were detected among the homologous sequences. Expression analyses and mapping focused on a selected Vf-homologous candidate gene (called Vf2ARD) identified in resistant Malus genotypes known for carrying other scab resistance genes than Vf. RT-PCR experiments showed that Vf2ARD is expressed under pathogen-free conditions. The results of a quantitative PCR-based transcription profiling suggest that this gene is scab-inducible in some resistant cultivars. Vf2ARD has been mapped on linkage group LG 1. It is separated from the Vf gene cluster with a genetic distance of about 2 cM and might be a member of a second Vf -like locus on apple linkage group LG 1. [ABSTRACT FROM AUTHOR]
- Subjects :
- GENES
HEREDITY
GENETIC polymorphisms
PROTEINS
BREEDING
AMINO acids
Subjects
Details
- Language :
- English
- ISSN :
- 01799541
- Volume :
- 128
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Plant Breeding
- Publication Type :
- Academic Journal
- Accession number :
- 36269632
- Full Text :
- https://doi.org/10.1111/j.1439-0523.2008.01537.x