De novo assembly and annotation of Caesalpinia bonducella L. seed transcriptome identifies key genes in the biosynthesis of bonducellin, a homoisoflavonoid

Caesalpinia bonducella L. is a traditional medicinal plant containing a potential homoisoflavonoid, bonducellin, with therapeutic values against polycystic ovary syndrome, oxidative damage, pathogenic bacteria, irregular menstrual cycle, ovarian cancer and diabetes. Owing to the multi-therapeutic properties of bonducellin, knowledge of its biosynthetic pathway genes will help understand its regulatory mechanism and thus improve the yield. This study sequenced C. bonducella seed mRNA transcriptome to identify the genes in bonducellin biosynthesis. Before this, the presence of bonducellin in the seed samples was analysed by HPLC using the chemically synthesised bonducellin as the standard. Seven key genes encoding enzymes involved in the synthesis of bonducellin via the phenylpropanoid pathway were identified. The expression of selective genes from the bonducellin biosynthetic pathway was validated using qRT-PCR and comparable with RNA-Seq data. Here, we put forth the sequences of 67,560 genes from C. bonducella and highlight the bonducellin biosynthetic pathway genes.