Regulation Mechanism of MYC Family Transcription Factors in Jasmonic Acid Signalling Pathway on Taxol Biosynthesis

Abstract

Paclitaxel is an important anticancer drug. The phytohormone jasmonic acid can significantly induce the biosynthesis of paclitaxel in Taxus, but the molecular mechanism has not yet been resolved. To establish the jasmonic acid signalling pathway of Taxus media, based on the gene of the jasmonic acid signalling pathway of Arabidopsis thaliana, sequence analysis was performed to isolate the jasmonic acid signal from the transcriptome, a transcriptional cluster of pathway gene homologs and the full length of 22 genes were obtained by RACE PCR at 5′ and 3′: two EI ubiquitin ligase genes, COI1-1 and COI1-2;7 MYC bHLH type transcription factor (MYC2, MYC3, MYC4, JAM1, JAM2, EGL3, TT8); 12 JAZ genes containing the ZIM domain; and MED25, one of the components of the transcriptional complex. The protein interaction between each were confirmed by yeast two hybridization and bimolecular fluorescence complementation based on similar genes interaction in Arabidopsis. A similar jasmonate signaling pathway was illustrated in T. media. All known paclitaxel biosynthesis genes promoters were isolated by genome walker PCR. To investigate the jasmonate signaling effect on these genes’ expression, the transcription activity of MYC2, MYC3 and MYC4 on these promoters were examined. There are 12, 10 and 11 paclitaxel biosynthesis genes promoters that could be activated by MYC2, MYC3 and MYC4.

Omic analysis of the endangered Taxaceae species Pseudotaxus chienii revealed the differences in taxol biosynthesis pathway between Pseudotaxus and Taxus yunnanensis trees

“…The MYC TFs are key regulators of the jasmonic acid (JA) signaling pathway and MeJA can improve the production of taxol [52]. In T. media, a number of biosynthesis gene promoters could be activated by MYC2, MYC3 and MYC4 [53]. In our study, 3 of 4 MYC TFs showed differential expressions, indicating potential differences in MYC-mediated JA signaling transduction between P. chienii and T. yunnanensis [54].…”

TcMYB29a, an ABA-Responsive R2R3-MYB Transcriptional Factor, Upregulates Taxol Biosynthesis in Taxus chinensis

“…Transcription factors play important roles in the biosynthesis of secondary metabolites. In the Taxus species, several TFs, including WRKYs and ERFs in T. chinensis, MYCs in T. cuspidata and T. chinensis, and MYB in T. media, were proved as being involved in the taxol biosynthesis pathway (Li et al, 2013;Lenka et al, 2015;Zhang et al, 2015Zhang et al, , 2018Cui et al, 2019;Yu et al, 2021). Although MYB family genes have been characterized from different plants, little is known about its specific functions and mechanisms on the regulation of taxol biosynthesis in Taxus (yew).…”

“…The interaction between jasmonate ZIMdomain (JAZ) proteins and MYC proteins is also detected in Taxus media in a similar mode of action as in model plants. In a model, JAZs can bind with MYCs and inhibit their transcriptional activities (Cui et al, 2019; Figure 1). In Taxus cuspidata, three JA-inducted MYC TFs, TcJAMYC1, TcJAMYC2, and TcJAMYC4, are verified to be involved in the negative regulation of the expression of taxol biosynthetic genes in Taxus cuspidata (Lenka et al, 2015).…”

Mekanisme Respon Tanaman Terhadap Cekaman Kekeringan

“…Sementara itu, MYC (myelocytomatosis oncogene) mempunyai karakter spesifik berupa motif bHLH (basic-helix-loophelix) dan bZIP (basic leucine zipper) (Zhu et al, 2003). Pada bagian motif bHLH inilah dimungkinkan terjadinya binding antara MYC dengan molekul lainnya membentuk struktur bimolekuler untuk meregulasi proses transkripsi pada gen trarget (Cui et al, 2019).…”