Metabolic engineering of terpene biosynthesis in plants using a trichome‐specific transcription factor Ms YABBY 5 from spearmint ( Mentha spicata )

• Published in: Plant biotechnology journal 2016-07, Vol.14 (7), p.1619-1632
• Main Authors: Wang, Qian, Reddy, Vaishnavi Amarr, Panicker, Deepa, Mao, Hui‐Zhu, Kumar, Nadimuthu, Rajan, Chakravarthy, Venkatesh, Prasanna Nori, Chua, Nam‐Hai, Sarojam, Rajani
• Format: Article
• Language: English
• ISSN: 1467-7644; 1467-7652
• DOI: 10.1111/pbi.12525

In many aromatic plants including spearmint ( Mentha spicata ), the sites of secondary metabolite production are tiny specialized structures called peltate glandular trichomes ( PGT ). Having high commercial values, these secondary metabolites are exploited largely as flavours, fragrances and pharmaceuticals. But, knowledge about transcription factors (TFs) that regulate secondary metabolism in PGT remains elusive. Understanding the role of TFs in secondary metabolism pathway will aid in metabolic engineering for increased yield of secondary metabolites and also the development of new production techniques for valuable metabolites. Here, we isolated and functionally characterized a novel Ms YABBY 5 gene that is preferentially expressed in PGT of spearmint. We generated transgenic plants in which Ms YABBY 5 was either overexpressed or silenced using RNA interference ( RNA i). Analysis of the transgenic lines showed that the reduced expression of Ms YABBY 5 led to increased levels of terpenes and that overexpression decreased terpene levels. Additionally, ectopic expression of Ms YABBY 5 in Ocimum basilicum and Nicotiana sylvestris decreased secondary metabolite production in them, suggesting that the encoded transcription factor is probably a repressor of secondary metabolism.