Triticum aestivum cultivar:Chara Transcriptome or Gene expression

Bread wheat (Triticum aestivum L.) is an allopolyploid species that contains three ancestral genomes. Therefore, potentially three homoeologous copies exist for any given gene in the wheat genome. Whether different homoeologs are differentially expressed (homoeolog expression bias) in response to biotic and abiotic stresses in wheat is poorly understood. In this study, we used an RNA-seq approach to analyze homoeolog-specific global gene expression patterns during infection by the fungal pathogen Fusarium pseudograminearum, which causes crown rot disease. We substantially increased the number of known homoeologous gene sets in wheat. Our analyses revealed patterns of differential expression among homoeologs under both control and infection conditions, indicating homoeolog expression bias underpins a large proportion of the wheat transcriptome. We found that B and D subgenomes disproportionately contributed to differentially expressed genes during plant defense. Furthermore, we observed that the degree of responsiveness to pathogen infection varied among homoeologous genes and we use the term “homoeolog induction bias” to refer to this phenomenon. Further understanding how homoeolog expression and induction bias impacts biotic stress responses will assist the improvement of biotic stress tolerance in elite wheat cultivars.