Search Results (3)

Leaf rust (Puccinia triticina) is a common disease that causes significant yield losses in wheat. The most frequently used methods to control leaf rust are the application of fungicides and the cultivation of resistant genotypes. However, high genetic diversity and associated adaptability of pathogen populations hamper achieving durable resistance in wheat. Emerging alternatives, such as microbial priming, may represent an effective measure to stimulate plant defense mechanisms and could serve as a means of controlling a broad range of pathogens. In this study, 175 wheat genotypes were inoculated with two bacterial strains: Ensifer meliloti strain expR⁺ch (producing N-acyl homoserine lactone (AHL)) or transformed E. meliloti carrying the lactonase gene attM (control). In total, 21 genotypes indicated higher resistance upon bacterial AHL priming. Subsequently, the phenotypic data of 175 genotypes combined with 9917 single-nucleotide polymorphisms (SNPs) in a genome-wide association study to identify quantitative trait loci (QTLs) and associated markers for relative infection under attM and expR⁺ch conditions and priming efficiency using the Genome Association and Prediction Integrated Tool (GAPIT). In total, 15 QTLs for relative infection under both conditions and priming efficiency were identified on chromosomes 1A, 1B, 2A, 3A, 3B, 3D, 6A, and 6B, which may represent targets for wheat breeding for priming and leaf-rust resistance. Full article

An MSM/Ms strain was established using Japanese wild mice, which exhibit resistance to several phenotypes associated with aging, such as obesity, inflammation, and tumorigenesis, compared to common inbred mouse strains. MSM/Ms strain is resistant to age-related hearing loss, and their auditory abilities are sustained for long durations. The age-related hearing loss 3 (ahl3) locus contributes to age-related hearing in MSM/Ms strain. We generated ahl3 congenic strains by transferring a genomic region on chromosome 17 from MSM/Ms mice into C57BL/6J mice. Although C57BL/6J mice develop age-related hearing loss because of the ahl allele of the cadherin 23 gene, the development of middle- to high-frequency hearing loss was significantly delayed in an ahl3 congenic strain. Moreover, the novel age-related hearing loss 10 (ahl10) locus associated with age-related hearing resistance in MSM/Ms strain was mapped to chromosome 12. Although the resistance effects in ahl10 congenic strain were slightly weaker than those in ahl3 congenic strain, slow progression of age-related hearing loss was confirmed in ahl10 congenic strain despite harboring the ahl allele of cadherin 23. These results suggest that causative genes and polymorphisms of the ahl3 and ahl10 loci are important targets for the prevention and treatment of age-related hearing loss. Full article

In many plant–pathogen interactions, the host resistance is governed by a combinatorial action of multiple genes termed as quantitative disease resistance (QDR). Three decades of genetic research on economically important interaction of chickpea (Cicer arietinum L.) and Ascochyta rabiei has revealed quantitative nature of host resistance. Despite various genomic studies in chickpea-Ascochyta system, identification of narrowed QTL/gene remains elusive. We utilized a next-generation genomic tool, namely multiple quantitative trait loci sequencing (mQTL-seq), to trounce the hurdles in revealing QDR genes against Ascochyta blight (AB). The mQTL-seq analysis revealed two major QTLs (qABR4.1 and qABR4.2) and a novel minor QTL (qABR4.3) on assembled Ca4 chickpea chromosome that provides resistance against AB. Under the major qABR4.1, a transcriptional regulator CaAHL18 was identified as a candidate gene and CaNIP8 marker was developed from its polymorphic cis-regulatory region for molecular breeding. We are further fine-mapping the major qABR4.2 (27.55–33.49 Mb) and novel minor qABR4.3 (38.78–39.48 Mb) to elucidate the candidate genes and their molecular mechanism of resistance. Up until now, the second major QTL, qABR4.2 is narrowed to ~1.41 Mb from 5.41 Mb region via utilizing bi-parental CRIL-7 population genotyping and association analysis in various chickpea accessions. Further, to translate the obtained genetic information from our AB resistance study, we intend to introgress multiple fungal resistance loci (for AB and FW resistant desi accessions) in few selected higher yielding cultivated chickpea varieties. Our combinatorial approaches have helped in overcoming the chickpea-AB genetic mapping associated problems of AB resistance loci fine-mapping and their utilization in molecular breeding. Consequently, our work will provide landmark information on chickpea AB resistance for the convenience of biotechnologists and breeders. Full article