Development and Validation of Thinopyrum elongatum–Expressed Molecular Markers Specific for the Long Arm of Chromosome 7E

Abstract

The ditelocentric addition line CS‐7EL of the spring wheat (Triticum aestivum L.) cultivar Chinese Spring (CS) contains the long arm of the chromosome 7E from Thinopyrum elongatum (CS‐7EL), which confers high resistance to Fusarium head blight. It is of great interest to breeders to integrate the resistance locus (loci) from Th. elongatum into commercial wheat varieties. The objectives of this study were to identify candidate genes expressed from the 7EL chromosome of CS‐7EL, to develop 7EL‐specific molecular markers, and to validate their usefulness for characterizing recombination between one of the group 7 chromosomes of wheat and Th. elongatum. High‐throughput sequencing of Fusarium graminearum–infected and control CS and CS‐7EL cDNA libraries was performed using RNA‐Seq. A stepwise bioinformatics strategy was applied to assemble the sequences obtained from RNA‐Seq and to create a conservative list of candidate genes expressed from the foreign chromosome 7EL. Polymerase chain reaction primer pairs were designed and tested for 135 candidate genes. A total of 48 expressed molecular markers specific for the chromosome 7EL were successfully developed. Screening of progenies from two BC1F2 families from the cross CS‐7E(7D) × 2*CSph1b showed that these markers are useful for characterizing recombination events between the chromosomes 7D from wheat and 7E from Th. elongatum.

Transcriptome dynamics associated with resistance and susceptibility against fusarium head blight in four wheat genotypes

“…Heads at mid-anthesis were point inoculated with either water (control), or Fg (strain DAOM233423). Plant growth, inoculation and infection conditions were described in detail previously [ 93 ]. Inoculated spikelet samples were collected in triplicate (from 5 heads per replicate) at 2 and 4 days post inoculation (dpi).…”

Genome-wide analysis of the polyamine oxidase gene family in wheat (Triticum aestivumL.) reveals involvement in temperature stress response

“…6B) was the only case where TaPAO11 genes which are located on the long arm of homoeologous group 7, were not expressed under both normal and Fusarium stress conditions. This result suggests that the examined wheat genotype in this case might be a ditelocentric addition line CS-7EL(7D) where the 7DL chromosome arm has been substituted by 7EL arm of Thinipyrum elongatum [43], subsequently affecting gene expression.…”

Genome-wide analysis of the polyamine oxidase gene family in wheat (Triticum aestivum L.) reveals involvement in temperature stress response

“…Fig 6B) was the only case where TaPAO11 genes which are located on the long arm of homoeologous group 7, were not expressed under both normal and Fusarium stress conditions. This result suggests that the examined wheat genotype in this case might be a ditelocentric addition line CS-7EL(7D) where the 7DL chromosome arm has been substituted by 7EL arm of Thinipyrum elongatum [43], subsequently affecting gene expression.…”

“…RNAseq data of 30 TaPAO genes was retrieved from www.wheat-expression.com [41] as processed expression values in transcripts per million (TPM) for all the available tissues and developmental stages [42] and for response to different stresses including Fusarium [43,44], cold [45], Zymoseptoria [46], heat and drought [47], phosphorous starvation [48], powdery mildew [49] and PEG (https://www.ebi.ac.uk/ena/browser/view/PRJNA306536). TaPAO gene expression values were transformed and used to generate barplots in R. Count matrix data of all experiments were also downloaded and used for differential gene expression analysis, using the DESeq2 package [50] to statistically compare the mean expression level of each TaPAO gene between control and stress conditions.…”