NBS-LRR-RGAs in roses

Diversity, genomic organization, expression and chromosomal location

authored by
A. Hattendorf, T. Debener
Abstract

Degenerate oligonucleotide primers targeting conserved motifs within the NBS region of nucleotide binding site (NBS)-leucine-rich repeat (LRR) resistance (R) genes were used to isolate resistance gene analogs (RGAs) from roses. A large RGA sublibrary consisting of 7000 clones was established. Sixty-seven percent of this sublibrary has been characterized and contains at least 40 unique RGA families of variable sizes, which could be subdivided further into the TIR (toll-/ interleukin-1 receptor) and the LZ (leucine zipper) group. TIR- and LZ-RGAs show a clear phylo- genetic separation, while distances between the single members of the LZ group are larger. The RGAs were organized as single-, low- and multicopy loci in the rose genome, but none of the analyzed sequences was conserved in Prunus cerasus. We studied the expression of some of the rose RGAs in a black spot resistant rose genotype and identified several candidates probably involved directly in the resistance reaction against black spot or in general stress responses. Finally, we integrated the RGAs into two different rose chromosome maps, which also contain the single dominant R genes Rdrl against black spot and Rppl against powDery mildew (PM) and several QTL (quantitative trait loci) involved in PM resistance. We identified some RGAs in chromosomal regions together with QTL for PM resistance as well as a number of RGA clusters probably indicating genomic regions containing not yet identified R genes.

Organisation(s)
Institute of Plant Genetics
Section Molecular Plant Breeding
Type
Article
Journal
Acta Horticulturae
Volume
751
Pages
151-162
No. of pages
12
ISSN
0567-7572
Publication date
2007
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Horticulture
Electronic version(s)
https://doi.org/10.17660/ActaHortic.2007.751.17 (Access: Unknown)