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

Abstract

In order to survive sub-zero temperatures, some plants undergo cold acclimation where low, non-freezing temperatures and/or shortened day lengths allow cold hardening and survival during subsequent freeze events. Central to this response is the plasma membrane, where low-temperature is perceived and cellular homeostasis must be preserved by maintaining membrane integrity. Here, we present the first plasma membrane proteome of cold-acclimated Brachypodium distachyon, a model species for the study of monocot crops. A time course experiment investigated cold acclimation-induced changes in the proteome following two-phase partitioning plasma membrane enrichment and label-free quantification by nano-liquid chromatography mass spectrophotometry. Two days of cold acclimation were sufficient for membrane protection as well as an initial increase in sugar levels, and coincided with a significant change in the abundance of 154 proteins. Prolonged cold acclimation resulted in further increases in soluble sugars and abundance changes in more than 680 proteins, suggesting both a necessary early response to low-temperature treatment, as well as a sustained cold acclimation response elicited over several days. A meta-analysis revealed that the identified plasma membrane proteins have known roles in low-temperature tolerance, metabolism, transport, and pathogen defense as well as drought, osmotic stress and salt resistance suggesting crosstalk between stress responses, such that cold acclimation may prime plants for other abiotic and biotic stresses. The plasma membrane proteins identified here present keys to an understanding of cold tolerance in monocot crops and the hope of addressing economic losses associated with modern climate-mediated increases in frost events.

Wild barley (Hordeum spontaneum) and landraces (Hordeum vulgare) from Turkey contain an abundance of novel Rhynchosporium commune resistance loci

“…The barley populations utilized in this study consisted of 105 Hordeum spontaneum genotypes and 198 barley landraces previously described by Clare et al (2021). These genotypes were obtained from the Central Research Institute for Field Crops located in Ankara, Turkey.…”

“…This high level of pathogen diversity also exempli es the need to identify new sources of scald resistance in diverse barley populations. These efforts are important for durable resistance because of the genetic bottlenecks created in modern breeding programs (Clare et al 2021).…”

“…In addition, association mapping within the Scottish 'Bere' landrace barley population, used due to the suspected Northwestern Europe origin of R. commune, also identi ed eight loci (Cope et al 2021). The work by Clare et al (2021) recently demonstrated that despite low marker density, novel resistance/susceptibility loci against fungal pathogens with complex host-pathogen genetic interactions can be identi ed by association mapping using natural wild and landrace barley populations. The work reported here relied on the previously reported genotyping data of Clare et al (2021) and identi ed an abundance of novel resistance loci within the barley-R. commune interaction from wild and landrace barley of Turkish origin.…”

“…The work by Clare et al (2021) recently demonstrated that despite low marker density, novel resistance/susceptibility loci against fungal pathogens with complex host-pathogen genetic interactions can be identi ed by association mapping using natural wild and landrace barley populations. The work reported here relied on the previously reported genotyping data of Clare et al (2021) and identi ed an abundance of novel resistance loci within the barley-R. commune interaction from wild and landrace barley of Turkish origin. This diversity of scald resistance genes is remarkable considering that the barley accessions are from the barley origin of domestication (Fertile Crescent).…”

Screening of stable resistant accessions and identification of resistance loci to Barley yellow mosaic virus disease

“…According to incomplete data, 647 QTLs (including duplicate or redundant loci) for disease resistance to all pathogens have been reported by GWAS in barley to date utilizing a mixed linear model (MLM) analysis ( Igartua, Cantalapiedra & Casas, 2019 ), including Fusarium head blight resistance loci ( Massman et al, 2011 ; Mamo, 2015 ), stem rust resistance loci ( Turuspekov et al, 2016 ) and stripe rust resistance loci ( Belcher et al, 2018 ). Recently, GWAS was performed using the fixed and random model circulating probability unification (FarmCPU) approach to identify barley scald resistance genes ( Hautsalo et al, 2021 ) and net blotch resistance loci ( Clare et al, 2021 ). Compared with the traditional MLM analysis, the FarmCPU approach shortens the calculation time and improves the efficiency of QTL identification ( Liu et al, 2016 ).…”