Dataset Information

Bulked segregant analysis RNA-seq (BSR-Seq) validated a stem resistance locus in Aegilops umbellulata, a wild relative of wheat.

ABSTRACT: Many disease resistance genes that have been transferred from wild relatives to cultivated wheat have played a significant role in wheat production worldwide. Ae. umbellulata is one of the species within the genus Aegilops that have been successfully used as sources of resistance genes to leaf rust, stem rust and powdery mildew. The objectives of the current work was to validate the map position of a major QTL that confers resistance to the stem rust pathogen races Ug99 (TTKSK) and TTTTF with an independent bi-parental mapping population and to refine the QTL region with a bulk segregant analysis approach. Two F2 bi-parental mapping populations were developed from stem rust resistant Ae. umbellulata accessions (PI 298905 and PI 5422375) and stem rust susceptible accessions (PI 542369 and PI 554395). Firstly, one of the two populations was used to map the chromosome location of the resistance gene. Later on, the 2nd population was used to validate the chromosome location in combination with a bulk segregant analysis approach. For the bulk segregant analysis, RNA was extracted from a bulk of leaf tissues of 12 homozygous resistant F3 families, and a separate bulk of 11 susceptible homozygous F3 families derived from the PI 5422375 and PI 554395 cross. The RNA samples of the two bulks and the two parents were sequenced for SNPs identification. Stem rust resistance QTL was validated on chromosome 2U of Ae. umbellulata in the same region in both populations. With bulk segregant analysis, the QTL position was delimited within 3.2 Mbp. Although there were a large number of genes in the orthologous region of the detected QTL on chromosome 2D of Ae. tauschii, we detected only two Ae. umbellulata NLR genes which can be considered as a potential candidate genes.

SUBMITTER: Edae EA

PROVIDER: S-EPMC6754143 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

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Bulked segregant analysis RNA-seq (BSR-Seq) validated a stem resistance locus in Aegilops umbellulata, a wild relative of wheat.

Edae Erena A EA Rouse Matthew N MN

PloS one 20190920 9

Many disease resistance genes that have been transferred from wild relatives to cultivated wheat have played a significant role in wheat production worldwide. Ae. umbellulata is one of the species within the genus Aegilops that have been successfully used as sources of resistance genes to leaf rust, stem rust and powdery mildew. The objectives of the current work was to validate the map position of a major QTL that confers resistance to the stem rust pathogen races Ug99 (TTKSK) and TTTTF with an ...[more]

PMID: 31539379

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Project description:Powdery mildew resistance gene Pm4b, originating from Triticum persicum, is effective against the prevalent Blumeria graminis f. sp. tritici (Bgt) isolates from certain regions of wheat production in China. The lack of tightly linked molecular markers with the target gene prevents the precise identification of Pm4b during the application of molecular marker-assisted selection (MAS). The strategy that combines the RNA-Seq technique and the bulked segregant analysis (BSR-Seq) was applied in an F2:3 mapping population (237 families) derived from a pair of isogenic lines VPM1/7∗Bainong 3217 F4 (carrying Pm4b) and Bainong 3217 to develop more closely linked molecular markers. RNA-Seq analysis of the two phenotypically contrasting RNA bulks prepared from the representative F2:3 families generated 20,745,939 and 25,867,480 high-quality read pairs, and 82.8 and 80.2% of them were uniquely mapped to the wheat whole genome draft assembly for the resistant and susceptible RNA bulks, respectively. Variant calling identified 283,866 raw single nucleotide polymorphisms (SNPs) and InDels between the two bulks. The SNPs that were closely associated with the powdery mildew resistance were concentrated on chromosome 2AL. Among the 84 variants that were potentially associated with the disease resistance trait, 46 variants were enriched in an about 25 Mb region at the distal end of chromosome arm 2AL. Four Pm4b-linked SNP markers were developed from these variants. Based on the sequences of Chinese Spring where these polymorphic SNPs were located, 98 SSR primer pairs were designed to develop distal markers flanking the Pm4b gene. Three SSR markers, Xics13, Xics43, and Xics76, were incorporated in the new genetic linkage map, which located Pm4b in a 3.0 cM genetic interval spanning a 6.7 Mb physical genomic region. This region had a collinear relationship with Brachypodium distachyon chromosome 5, rice chromosome 4, and sorghum chromosome 6. Seven genes associated with disease resistance were predicted in this collinear genomic region, which included C2 domain protein, peroxidase activity protein, protein kinases of PKc_like super family, Mlo family protein, and catalytic domain of the serine/threonine kinases (STKc_IRAK like super family). The markers developed in the present study facilitate identification of Pm4b during its MAS practice.

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Dataset Information

Bulked segregant analysis RNA-seq (BSR-Seq) validated a stem resistance locus in Aegilops umbellulata, a wild relative of wheat.

Publications

Bulked segregant analysis RNA-seq (BSR-Seq) validated a stem resistance locus in Aegilops umbellulata, a wild relative of wheat.

Similar Datasets

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