Abstract
Three-fourths of the recognition-dependent disease resistance genes (R-genes) identified in plants encode nucleotide binding site (NBS) leucine-rich repeat (LRR) proteins. NBS-LRR homologs have only been isolated on a limited scale from sunflower (Helianthus annuus L.), and most of the previously identified homologs are members of two large NBS-LRR clusters harboring downy mildew R-genes. We mined the sunflower EST database and used comparative genomics approaches to develop a deeper understanding of the diversity and distribution of NBS-LRR homologs in the sunflower genome. Collectively, 630 NBS-LRR homologs were identified, 88 by mining a database of 284,241 sunflower ESTs and 542 by sequencing 1,248 genomic DNA amplicons isolated from common and wild sunflower species. DNA markers were developed from 196 unique NBS-LRR sequences and facilitated genetic mapping of 167 NBS-LRR loci. The latter were distributed throughout the sunflower genome in 44 clusters or singletons. Wild species ESTs were a particularly rich source of novel NBS-LRR homologs, many of which were tightly linked to previously mapped downy mildew, rust, and broomrape R-genes. The DNA sequence and mapping resources described here should facilitate the discovery and isolation of recognition-dependent R-genes guarding sunflower from a broad spectrum of economically important diseases.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 111-125 |
| Number of pages | 15 |
| Journal | Molecular Genetics and Genomics |
| Volume | 280 |
| Issue number | 2 |
| DOIs | |
| State | Published - Aug 2008 |
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Keywords
- Compositae
- Helianthus
- Lactuca
- Resistance genes
ASJC Scopus subject areas
- Genetics
Cite this
Genetic diversity and genomic distribution of homologs encoding NBS-LRR disease resistance proteins in sunflower. / Radwan, Osman; Gandhi, Sonali; Heesacker, Adam; Whitaker, Brett; Taylor, Chris; Plocik, Alex; Kesseli, Richard; Kozik, Alexander; Michelmore, Richard W; Knapp, Steven J.
In: Molecular Genetics and Genomics, Vol. 280, No. 2, 08.2008, p. 111-125.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Genetic diversity and genomic distribution of homologs encoding NBS-LRR disease resistance proteins in sunflower
AU - Radwan, Osman
AU - Gandhi, Sonali
AU - Heesacker, Adam
AU - Whitaker, Brett
AU - Taylor, Chris
AU - Plocik, Alex
AU - Kesseli, Richard
AU - Kozik, Alexander
AU - Michelmore, Richard W
AU - Knapp, Steven J.
PY - 2008/8
Y1 - 2008/8
N2 - Three-fourths of the recognition-dependent disease resistance genes (R-genes) identified in plants encode nucleotide binding site (NBS) leucine-rich repeat (LRR) proteins. NBS-LRR homologs have only been isolated on a limited scale from sunflower (Helianthus annuus L.), and most of the previously identified homologs are members of two large NBS-LRR clusters harboring downy mildew R-genes. We mined the sunflower EST database and used comparative genomics approaches to develop a deeper understanding of the diversity and distribution of NBS-LRR homologs in the sunflower genome. Collectively, 630 NBS-LRR homologs were identified, 88 by mining a database of 284,241 sunflower ESTs and 542 by sequencing 1,248 genomic DNA amplicons isolated from common and wild sunflower species. DNA markers were developed from 196 unique NBS-LRR sequences and facilitated genetic mapping of 167 NBS-LRR loci. The latter were distributed throughout the sunflower genome in 44 clusters or singletons. Wild species ESTs were a particularly rich source of novel NBS-LRR homologs, many of which were tightly linked to previously mapped downy mildew, rust, and broomrape R-genes. The DNA sequence and mapping resources described here should facilitate the discovery and isolation of recognition-dependent R-genes guarding sunflower from a broad spectrum of economically important diseases.
AB - Three-fourths of the recognition-dependent disease resistance genes (R-genes) identified in plants encode nucleotide binding site (NBS) leucine-rich repeat (LRR) proteins. NBS-LRR homologs have only been isolated on a limited scale from sunflower (Helianthus annuus L.), and most of the previously identified homologs are members of two large NBS-LRR clusters harboring downy mildew R-genes. We mined the sunflower EST database and used comparative genomics approaches to develop a deeper understanding of the diversity and distribution of NBS-LRR homologs in the sunflower genome. Collectively, 630 NBS-LRR homologs were identified, 88 by mining a database of 284,241 sunflower ESTs and 542 by sequencing 1,248 genomic DNA amplicons isolated from common and wild sunflower species. DNA markers were developed from 196 unique NBS-LRR sequences and facilitated genetic mapping of 167 NBS-LRR loci. The latter were distributed throughout the sunflower genome in 44 clusters or singletons. Wild species ESTs were a particularly rich source of novel NBS-LRR homologs, many of which were tightly linked to previously mapped downy mildew, rust, and broomrape R-genes. The DNA sequence and mapping resources described here should facilitate the discovery and isolation of recognition-dependent R-genes guarding sunflower from a broad spectrum of economically important diseases.
KW - Compositae
KW - Helianthus
KW - Lactuca
KW - Resistance genes
UR - http://www.scopus.com/inward/record.url?scp=48349132316&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=48349132316&partnerID=8YFLogxK
U2 - 10.1007/s00438-008-0346-1
DO - 10.1007/s00438-008-0346-1
M3 - Article
C2 - 18553106
AN - SCOPUS:48349132316
VL - 280
SP - 111
EP - 125
JO - Molecular Genetics and Genomics
JF - Molecular Genetics and Genomics
SN - 1617-4615
IS - 2
ER -