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)