Multidimensional regulation of transcription factors: decoding the comprehensive signals of plant secondary metabolism

Abstract

Plants synthesize an extensive array of secondary metabolites in response to diverse biotic and abiotic stresses. These metabolites function not only as defensive compounds but also constitute significant sources of nutrition and pharmaceuticals. However, the mechanisms governing the synthesis of these secondary metabolites have long been a central focus of research and continue to pose significant challenges. Transcription factors (TFs), serving as key regulators of secondary metabolite synthesis in plants, exhibit mechanisms of action that are still not fully understood. This review summarizes the latest research advancements on how plant transcription factors mediate the regulation of secondary metabolite biosynthesis through various signaling pathways, including light signaling, hormone signaling, MAPK signaling, the ubiquitin-proteasome pathway, epigenetic regulation, microbial interactions, and climate change. A deeper understanding of the mechanisms regulating transcription factors is expected to provide new insights into the biosynthesis of plant secondary metabolites.

Keywords: biosynthesis; mechanisms; secondary metabolites; signaling pathways; transcription factors.

Figure 1

Structural characteristics of typical transcription factors. (A) Structural features of four subclasses of MYB transcription factors, including primary and secondary structures. (B) Zinc finger structural characteristics and conserved domain sequences of the seven subclasses of WRKY transcription factors. (C) Helical structure of bHLH transcription factors. (D) Basic structure of AP2/ERF transcription factors. (E) Basic structure of bZIP transcription factors. (F) Basic structure of NAC transcription factors, with the white letters (A–E) representing different subdomains.

Figure 2

Terpene synthesis pathway. ACAT, acetyl-coenzyme A C-acetyl­ transferase; HMGS, 3-hydroxy-3-methylglutaryl coenzyme A synthase; HMGR, 3-hydroxy-3-methyl glutaryl coenzyme A reductase; PMK, phosphomevalonate kinase; MPD, mevalonate pyrophosphate decarboxylase; MVA, mevalonic acid; DXS, 1-deoxy-D-xylulose 5-phosphate synthase; DXR, 1-deoxy-D-xylulose-5-phosphate reductoisomerase; MEP, 2-C-methyl-D-erythritol 4-phosphate; IPP, isopenteny pyrophosphate; DMAPP, dimethylallyl diphosphate; GPPS, geranyl diphosphate synthase; GPP, geranyl diphosphate; GGPPS, geranylgeranyl pyrophosphate syn­thase; GGPP, geranylgeranyl diphosphate; CDP-ME,4-(cytidine5’-diphospho)-2-C-methyl-D-erythritol; CDP-MEP, 4-diphosphocytidyl-2-C-methyl-d-erythritol-2-phosphate; G3P,glyceraldehyde 3-phosphate; HMG-CoA,3-hydroxy-3-methylglutaryl-CoA; IDI, isopentenyl diphosphate isomerase; GFPP, geranylfarnesyl diphosphate; GFPPS, geranylfarnesyl diphosphate synthase; FPP, farnesyl pyrophosphate; TS, terpene synthase; MDD, mevalonate diphosphate decarboxylase; MVA-5-P, mevalonate 5-phosphate; MVA-5-PP, mevalonate 5-diphosphate; MPD, mevalonate phosphate decarboxylase; IPK, isopentenyl phosphate kinases; IP, isopentenyl phosphate; MDS, 2-C-methyl-D-erythritol 2,4-cyclodiphosphate synthase; HDS, (E)-4-hydroxy-3-methylbut-2-enyl diphosphate synthase; MCT, 2-C-methyl-D-erythritol 4phosphate synthase; CMK, CDP-ME-kinase; HMBPP, 4-hydroxy-3-methylbut-2-enyl-diphosphate.

Figure 3

Synthetic pathways of flavonoids and alkaloids. R1, R2, R3 and R4 are substituted by different groups to form different compounds. ANS, anthocyanidin synthase; CHS, chalcone synthase; PAL, phenylalanine ammonia-lyase.

Figure 4

The potential pharmacological effects of plant secondary metabolites in the treatment of human diseases.

Figure 5

Transcription factors mediate various signal transduction and participate in the accumulation of plant secondary metabolites.

Figure 6

A schematic model of the potential molecular mechanisms by which various environmental and climatic stimuli regulate the synthesis of plant secondary metabolites (Modified from Sun and Fernie, 2024).