Genome-wide identification and expression of P450 genes in Sorghum bicolor
AbstractBackgroundCytochromes P450 play a key role in plant secondary metabolism and environmental stress responses. Considering the economic importance of Sorghum bicolor, a systematic identification and analysis of its P450 genes may provide important insights into the evolutionary relationships and functions of these genes.ResultsIn this study, we used bioinformatics tools and transcriptome data to identify 33 P450 genes on different sorghum chromosomes. These genes were divided into four families according to phylogeny and similarities with Arabidopsis thaliana P450 genes. All four SbP450 genes in the CYP86 family lacked introns (i.e., only one exon). SbP450 genes in the other three families contained more than one intron. Moreover, three pairs of SbP450 genes were revealed as tandem repeats. The predicted subcellular localization results showed that most of the SbP450 proteins were located in chloroplasts (exceptions were SbP450-7/10/14/31). In addition, 10 conserved motifs were identified in SbP450 proteins, all of which had a typical P450 domain. SbP450 promoter regions included various cis-acting elements related to plant hormones and stress responses. On the basis of KEGG pathway and GO term enrichment analyses, the 33 SbP450 proteins were mainly associated with redox pathways, secondary metabolite biosynthesis, metabolism, and flavonoid biosynthesis. Furthermore, a gene expression analysis revealed sorghum tissue-specific SbP450 expression patterns, which may be closely related to their functions. According to a quantitative real-time polymerase chain reaction analysis, SbP450 genes are likely involved in sorghum defense responses to abiotic stress.Conclusion These findings provide a basis for future studies on the biological functions of sorghum SbP450 genes.Keywords SbP450, Gene family, Sorghum bicolor, Expression analysis