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Key message: Powdery mildew resistance gene MlWE74, originated from wild emmer wheat accession G-748-M, was mapped in an NBS-LRR gene cluster of chromosome 2BS. Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is a globally devastating disease. Wild emmer wheat (Triticum turgidum var. dicoccoides) is a valuable genetic resource for improving disease resistance in common wheat. A powdery mildew resistance gene was transferred to hexaploid wheat line WE74 from wild emmer accession G-748-M. Genetic analysis revealed that the powdery mildew resistance in WE74 is controlled by a single dominant gene, herein temporarily designated MlWE74. Bulked segregant analysis (BSA) and molecular mapping delimited MlWE74 to the terminal region of chromosome 2BS flanking by markers WGGBD412 and WGGBH346 within a genetic interval of 0.25 cM and corresponding to 799.9 kb genomic region in the Zavitan reference sequence. Sequence annotation revealed two phosphoglycerate mutase-like genes, an alpha/beta-hydrolases gene, and five NBS-LRR disease resistance genes that could serve as candidates for map-based cloning of MlWE74. The geographical location analysis indicated that MlWE74 is mainly distributed in Rosh Pinna and Amirim regions, in the northern part of Israel, where environmental conditions are favorable to the occurrence of powdery mildew. Moreover, the co-segregated marker WGGBD425 is helpful in marker-assisted transfer of MlWE74 into elite cultivars. [ABSTRACT FROM AUTHOR]

The abovementioned results imply that the silent genetic loci like I Pm41b i are a valuable resource of genetic variation in the wheat genome and therefore could be potentially utilized to enrich the genetic diversity in wheat breeding. Keywords: Pm41; allelic variation; genetic diversity; transposon; gene silencing EN Pm41 allelic variation genetic diversity transposon gene silencing 2039 2041 3 11/01/22 20221101 NES 221101 Common wheat ( I Triticum aestivum i . [Extracted from the article]

Summary: Powdery mildew poses severe threats to wheat production. The most sustainable way to control this disease is through planting resistant cultivars.We report the map‐based cloning of the powdery mildew resistance allele Pm5e from a Chinese wheat landrace. We applied a two‐step bulked segregant RNA sequencing (BSR‐Seq) approach in developing tightly linked or co‐segregating markers to Pm5e. The first BSR‐Seq used phenotypically contrasting bulks of recombinant inbred lines (RILs) to identify Pm5e‐linked markers. The second BSR‐Seq utilized bulks of genetic recombinants screened from a fine‐mapping population to precisely quantify the associated genomic variation in the mapping interval, and identified the Pm5e candidate genes.The function of Pm5e was validated by transgenic assay, loss‐of‐function mutants and haplotype association analysis. Pm5e encodes a nucleotide‐binding domain leucine‐rich‐repeat‐containing (NLR) protein. A rare nonsynonymous single nucleotide variant (SNV) within the C‐terminal leucine rich repeat (LRR) domain is responsible for the gain of powdery mildew resistance function of Pm5e, an allele endemic to wheat landraces of Shaanxi province of China.Results from this study demonstrate the value of landraces in discovering useful genes for modern wheat breeding. The key SNV associated with powdery mildew resistance will be useful for marker‐assisted selection of Pm5e in wheat breeding programs. [ABSTRACT FROM AUTHOR]

Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is one of the most destructive diseases that pose a great threat to wheat production. Wheat landraces represent a rich source of powdery mildew resistance. Here, we report the map-based cloning of powdery mildew resistance gene Pm24 from Chinese wheat landrace Hulutou. It encodes a tandem kinase protein (TKP) with putative kinase-pseudokinase domains, designated WHEAT TANDEM KINASE 3 (WTK3). The resistance function of Pm24 was validated by transgenic assay, independent mutants, and allelic association analyses. Haplotype analysis revealed that a rare 6-bp natural deletion of lysine-glycine codons, endemic to wheat landraces of Shaanxi Province, China, in the kinase I domain (Kin I) of WTK3 is critical for the resistance function. Transgenic assay of WTK3 chimeric variants revealed that only the specific two amino acid deletion, rather than any of the single or more amino acid deletions, in the Kin I of WTK3 is responsible for gaining the resistance function of WTK3 against the Bgt fungus. Powdery mildew is a major threat to world wheat yields. Here the authors describe the map-based cloning of Pm24, a gain-of-function powdery mildew resistance allele that encodes a tandem kinase-pseudokinase protein with a deletion in a kinase domain that is endemic to certain wheat landraces. [ABSTRACT FROM AUTHOR]

Bulked segregant CGT-Seq-facilitated map-based cloning of a powdery mildew resistance gene originating from wild emmer wheat (Triticum dicoccoides) In this study, we cloned the powdery mildew resistance allele I MlWE18 i ( I NLR SP WE18 sp i ) whose locus is not present in the wheat reference genomes using a combined BSA and CGT-seq strategies. Most of the cloned wheat disease resistance genes are NLRs that tend to be PAVs between the resistance and susceptible genotypes, especially the genes derived from wild relatives (Li I et al i ., 2020; Walkowiak I et al i ., 2020). Keywords: BSA; ChIP-Seq; NLR; PAV EN BSA ChIP-Seq NLR PAV 1288 1290 3 07/28/21 20210701 NES 210701 Powdery mildew, caused by I Blumeria graminis i f. sp. I tritici i ( I Bgt i ), is a widely occurring foliar disease of wheat worldwide. [Extracted from the article]