Abstract
Background: Fusarium graminearum causes Fusarium head blight (FHB), a major disease problem worldwide. Resistance to FHB is controlled by quantitative trait loci (QTL) of which two are located on barley chromosomes 2H bin8 and 6H bin7. The mechanisms of resistance mediated by FHB QTL are poorly defined. Results: Near-isogenic lines (NILs) carrying Chevron-derived resistant alleles for the two QTL were developed and exhibited FHB resistance in field trials. To understand the molecular responses associated with resistance, transcriptomes of the NILs and recurrent parents (M69 and Lacey) were investigated with RNA sequencing (RNA-Seq) after F. graminearum or mock inoculation. A total of 2083 FHB-responsive transcripts were detected and provide a gene expression atlas for the barley-F. graminearum interaction. Comparative analysis of the 2Hb8 resistant (R) NIL and M69 revealed that the 2Hb8 R NIL exhibited an elevated defense response in the absence of fungal infection and responded quicker than M69 upon fungal infection. The 6Hb7 R NIL displayed a more rapid induction of a set of defense genes than Lacey during the early stage of fungal infection. Overlap of differentially accumulated genes were identified between the two R NILs, suggesting that certain responses may represent basal resistance to F. graminearum and/or general biotic stress response and were expressed by both resistant genotypes. Long noncoding RNAs (lncRNAs) have emerged as potential key regulators of transcription. A total of 12,366 lncRNAs were identified, of which 604 were FHB responsive. Conclusions: The current transcriptomic analysis revealed differential responses conferred by two QTL during F. graminearum infection and identified genes and lncRNAs that were associated with FHB resistance.
| Original language | English (US) |
|---|---|
| Article number | 387 |
| Journal | BMC Genomics |
| Volume | 17 |
| Issue number | 1 |
| DOIs | |
| State | Published - May 21 2016 |
Bibliographical note
Funding Information:We acknowledge Dr. Shiaoman Chao (USDA-ARS Cereal Crops Research unit) for genotyping the four genotypes with the barley iSelect SNP arrays, Dr. Yanhong Dong for the deoxynivalenol and ergosterol analyses of RNA-Seq and field samples, Dr. María Muñoz-Amatriaín for assisting with the Spotfire software, Dr. Ruth Dill-Macky for providing inoculum for field trials, and Dr. H. Corby Kistler and Xin Li for providing the PH-1 strain for inoculating RNA-Seq samples. Edward L. Shiefelbein, Guillermo Velasquez and Karen Beaubien are thanked for technical help with the St. Paul, MN FHB nursery trials. The project was supported by funding from U.S. Wheat and Barley Scab Initiative to G.J.M.
Publisher Copyright:
© 2016 Huang et al.
Keywords
- Barley
- Fusarium graminearum
- Fusarium head blight
- Hordeum vulgare
- QTL
- RNA-Seq
