TcbHLH14 a Jasmonate Associated MYC2-like Transcription Factor Positively Regulates Pyrethrin Biosynthesis in .

Natural pyrethrins have high application value, and are widely used as a green pesticide in crop pest prevention and control. Pyrethrins are mainly extracted from the flower heads of ; however, the natural content is low. Therefore, it is essential to understand the regulatory mechanisms underlying the synthesis of pyrethrins through identification of key transcription factors. We identified a gene encoding a MYC2-like transcription factor named from transcriptome, which is induced by methyl jasmonate. In the present study, we evaluated the regulatory effects and mechanisms of TcbHLH14 using expression analysis, a yeast one-hybrid assay, electrophoretic mobility shift assay, and overexpression/virus-induced gene silencing experiments. We found that TcbHLH14 can directly bind to the cis-elements of the pyrethrins synthesis genes and to activate their expression. The transient overexpression of TcbHLH14 enhanced expression of the and genes. Conversely, transient silencing of downregulated the expression of and and reduced the content of pyrethrins. In summary, these results indicate that the potential application of TcbHLH14 in improving the germplasm resources and provide a new insight into the regulatory network of pyrethrins biosynthesis of to further inform the development of engineering strategies for increasing pyrethrins contents.