Work

A MYC2-like transcription factor regulates MeJA biosynthesis underlying flower fragrance in Cymbidium faberi

Year: 2025

Type: article

Abstract: Cymbidium faberi is highly valued for its distinct floral scent, primarily consisting of methyl jasmonate (MeJA). This study aimed to elucidate the transcriptional regulation of MeJA biosynthesis in C. faberi , laying a theoretical foundation for enhancing fragrance in scentless Cymbidium varieties. We cloned four basic helix-loop-helix (bHLH) transcription factor genes ( CfbHLH5 , CfbHLH25 , CfbHLH31 , and CfMYC2-like ) that exhibit divergent roles in MeJA production. CfMYC2-like specifically represses CfJMT , a pivotal MeJA biosynthetic gene, by binding to the G-box element of its promoter, thereby inhibiting the positive regulatory function of CfbHLH5. Transient overexpression of CfMYC2-like in C. faberi protoplasts reduced MeJA-related gene expression, whereas CRISPR/Cas9-mediated mutation of CfMYC2-like markedly elevated MeJA levels in rhizomes. Furthermore, CfMYC2-like physically interacted with the AP2 transcription factor CfRAP2.4, limiting its ability to activate CfJMT . This mechanism underlies the low MeJA content observed in vegetative tissues and the robust MeJA emission during flowering. Collectively, our findings demonstrate that CfMYC2-like acts as a key regulator of MeJA biosynthesis in C. faberi and offer a promising avenue for improving floral scent in Cymbidium . Future research should further investigate the regulatory networks and environmental cues that modulate MeJA production, enhancing both the ornamental and commercial value of these orchids.

Source: Industrial Crops and Products

DOI: 10.1016/j.indcrop.2025.121818