Genome-wide identification and comparative analysis of diacylglycerol kinase (DGK) gene family and their expression profiling inBrassica napusunder abiotic stress

Background Diacylglycerol kinases (DGKs) are signaling enzymes that play pivotal roles in response to abiotic and biotic stresses by phosphorylating diacylglycerol (DAG) to form phosphatidic acid (PA). However, no comprehensive analysis of theDGKgene family had previously been reported inB. napusand its diploid progenitors (B. rapaandB. oleracea). Results In present study, we identified 21, 10, and 11DGKgenes fromB. napus,B. rapa, andB. oleracea, respectively, which all contained conserved catalytic domain and were further divided into three clusters. Molecular evolutionary analysis showed that speciation and whole-genome triplication (WGT) was critical for the divergence of duplicatedDGKgenes. RNA-seq transcriptome data revealed that, with the exception ofBnaDGK4andBnaDGK6,BnaDGKgenes have divergent expression patterns in most tissues. Furthermore, someDGKgenes were upregulated or downregulated in response to hormone treatment and metal ion (arsenic and cadmium) stress. Quantitative real-time PCR analysis revealed that differentBnaDGKgenes contribute to seed oil content. Conclusions Together, our results indicate thatDGKgenes have diverse roles in plant growth and development, hormone response, and metal ion stress, and in determining seed oil content, and lay a foundation for further elucidating the roles ofDGKsinBrassicaspecies.