Crop Biotech Update

Metabolic Engineering of Terpene Biosynthesis using a Transcription Factor MsYABBY5 from Spearmint

February 10, 2016

In aromatic plants like spearmint (Mentha spicata), secondary metabolite production happens in specialized structures called peltate glandular trichomes (PGT). These secondary metabolites are exploited as flavors, fragrances and pharmaceuticals. However, knowledge about transcription factors (TFs) that regulate secondary metabolism in PGT remains elusive.

Scientists led by Qian Wang of the National University of Singapore aim to study the role of TFs in secondary metabolism pathway in hopes of metabolic engineering for increased yield of secondary metabolites. The team isolated and characterized a novel MsYABBY5 gene that is expressed in PGT of spearmint. Transgenic plants with overexpressed and silenced MsYABBY5 were then generated.

Analysis of the transgenic lines showed that the reduced expression of MsYABBY5 led to increased levels of terpenes while overexpression decreased terpene levels. Moreover, expression of MsYABBY5 in Ocimum basilicum and Nicotiana sylvestris decreased their secondary metabolite production, suggesting that the transcription factor is a repressor of secondary metabolism.

For more on the study, read the full article in Plant Biotechnology Journal.