Tracing the transcriptomic changes of synthetic trigenomic allohexaploid in Brassica by RNA-Seq approach

We explored the transcriptomic changes of synthetic Brassica allohexaploid by comparing to its parents using a high-throughput RNA-Seq method. A total of 35644409 sequence reads were generated, and 32642 genes were aligned from the data. There were 29260, 29060 and 29697 genes identified in Brassica rapa, Brassica carinata, and Brassica allohexaploid, respectively. We screened differentially expressed genes (DEGs) by a standard of two-fold or greater change in expression and false discovery rate (FDR) no more than 0.001. As a result, 7397 DEGs were detected between Brassica hexaploid and its parents. A large proportion of the 3184 DEGs between Brassica hexaploid and its paternal parent B. rapa was involved in biosynthesis of secondary metabolites, plant-pathogen interaction, photosynthesis, and circadian rhythm. Between Brassica hexaploid and its maternal parent B. carinata, 2233 DEGs were screened. A lot of them had functions of plant-pathogen interaction, plant hormone signal transduction, ribosome, limonene and pinene degradation, photosynthesis, and also biosynthesis of secondary metabolites. In addition, we found many transcription factor genes, methyltransferase and methylation genes that showed differential expression between Brassica hexaploid and its parents. Overall design: Leaf mRNA profiles of Brassica rapa, Brassica carinata, and Brassica allohexaploid