Bivalent RNA Interference to Increase Isoflavone Biosynthesis in Soybean (Glycine max)

In this work, a bivalent RNA interference (RNAi) plant-transformation vector was constructed to silence both the flavanone 3-hydroxylase (F3H) gene and the flavone synthase II (GmFNSII) gene in soybean (Glycine max). Two further unit RNAi vectors were constructed for each of these two genes. RNAi-mediated suppression of these genes effectively regulated flavone and isoflavone production in hairy roots that arose from soybean cotyledons transformed with Agrobacterium rhizogenes ATCC15834. Notably, the bivalent RNAi vector had a significantly higher effect for increasing isoflavone production compared with the two unit RNAi vectors. The study highlighted molecular methods that could be used to enhance isoflavone production in soybean and demonstrated the challenges associated with such metabolic engineering for the production of plant natural products.