Biology subjects

Effertz, K.

Publications and source records attributed to Effertz, K..

3 recordsLinked to original sources

bioRxiv2024

Rpt5 encodes a receptor-like protein that provides broad and effective net form net blotch (Pyrenophora teres f. teres) resistance in barley

The foliar disease net form net blotch (NFNB), caused by the necrotrophic fungal pathogen Pyrenophora teres f. teres (Ptt), causes significant yield and quality losses of barley worldwide. Dominant resistance conferred by the Resistance to Pyrenophora teres 5(Rpt5) gene from barley line CI5791 is the broadest and most effective resistance reported in this pathosystem. The Rpt5 locus was identified in multiple independent genetic studies utilizing diverse host populations and Ptt isolates, and harbors both dominant Rpt5 resistance and isolate-specific susceptibility genes/alleles that are dominant in the absence of Rpt5, designated susceptibility to Pyrenophora teres 1 (Spt1). Ptt virulence and avirulence effectors from diverse pathogen isolates genetically interact with the Rpt5/Spt1 locus, suggesting a complex locus with a function targeted by the evolution of a diversity of pathogen effectors. High-resolution mapping utilizing 1,920 recombinant gametes from a CI5791 x Tifang biparental population, identified 12 candidate genes in an [~]4.6 Mb delimited region in the cv Morex V3 genome assembly, but is 1.1 - 2.2 Mb in the pangenome assemblies, containing 5-12 genes. Analysis revealed a strong correlation between the CI5791 allele of a receptor-like protein (RLP), provisionally designated Rpt5 candidate gene 1, (Rcg1), and broad Rpt5-mediated resistance. Two independent transformants of the CI5791 Rcg1 allele in the susceptible cv Golden Promise background showed significantly increased resistance when challenged with Rpt5 avirulent Ptt isolates 6A, 15A, and 0-1 compared to the Golden Promise wildtype. Thus, Rpt5, encodes an RLP and is the first net blotch resistance gene cloned in barley. Significance StatementNet form net blotch (NFNB) causes substantial yield and quality losses of barley worldwide. Despite decades of ongoing research into genetic resistance to Pyrenophora teres f. teres, the causal agent of NFNB, no host resistance or susceptibility genes in this pathosystem had been previously identified. We present the identification and validation of Rpt5, which confers the broadest and most effective resistance against NFNB. To our knowledge Rpt5 is the first genetically defined resistance gene in a monocot to encode an RLP.

plant biology↗

bioRxiv2023

Pathogen genetics identifies avirulence/virulence loci associated with barley chromosome 6H resistance in the Pyrenophora teres f. teres - barley interaction

Barley net form net blotch (NFNB) is a foliar disease caused by Pyrenophora teres f. teres. Barley line CIho5791, which harbors the chromosome 6H broad spectrum resistance gene Rpt5, displays dominant resistance to P. teres f. teres. To genetically characterize P. teres f. teres avirulence/virulence on the barley line CIho5791, we generated a P. teres f. teres mapping population using a cross between the Moroccan CIho5791-virulent isolate MorSM40-3, and the avirulent reference isolate 0-1. Genetic maps were generated for all 12 chromosomes (Ch) and quantitative trait locus (QTL) mapping identified two significant QTL associated with P. teres f. teres avirulence/virulence on CIho5791. The most significant QTL mapped to P. teres f. teres Ch1 where the virulent allele was contributed by MorSM40-3. A second QTL mapped to Ch8, however, this virulent allele was contributed by 0-1. The Ch1 and Ch8 loci accounted for 27 and 15% of the disease variation, respectively and the avirulent allele at the Ch1 locus was shown to be epistatic over the virulent allele at the Ch8 locus. Additionally, we used 177 sequenced P. teres f. teres isolates in a genome wide association study that identified the same Ch1 and Ch8 loci as the two most significant associations. Within the identified genomic regions, we identified several genes that encoded small secreted proteins, one or more of which may be responsible for overcoming the CIho5791 resistance. Results presented here demonstrate the complexity of avirulence/virulence in the P. teres f. teres - barley interaction.

genetics↗

bioRxiv2021

Genome wide association mapping of Pyrenophora teres f. maculata and Pyrenophora teres f. teres resistance loci utilizing natural Turkish wild and landrace barley populations

Unimproved landraces and wild relatives of crops are sources of genetic diversity that were lost post domestication in modern breeding programs. To tap into this rich resource, genome wide association studies in large plant genomes have enabled the rapid genetic characterization of desired traits from natural landrace and wild populations. Wild barley (Hordeum spontaneum), the progenitor of domesticated barley (H. vulgare), is dispersed across Asia and North Africa, and has co-evolved with the ascomycetous fungal pathogens Pyrenophora teres f. teres and P. teres f. maculata, the casual agents of the diseases net form of net blotch and spot form of net blotch, respectively. Thus, these wild and local adapted barley landraces from the region of origin of both the host and pathogen represent a diverse gene pool to identify new sources of resistance, due to millions of years of co-evolution. The barley - P. teres pathosystem is governed by complex genetic interactions with dominant, recessive, and incomplete resistances and susceptibilities, with many isolate-specific interactions. Here we provide the first genome wide association study of wild and landrace barley from the Fertile Crescent for resistance to both forms of P. teres. A total of 14 loci, four against P. teres f. maculata and ten against Pyrenophora teres f. teres, were identified in both wild and landrace populations, showing that both are genetic reservoirs for novel sources of resistance. We also highlight the importance of using multiple algorithms to both identify and validate additional loci.

genetics↗