Combinatorial Control of Plant Specialized Metabolism: Mechanisms, Functions, and Consequences

Abstract

Plants constantly perceive internal and external cues, many of which they need to address to safeguard their proper development and survival. They respond to these cues by selective activation of specific metabolic pathways involving a plethora of molecular players that act and interact in complex networks. In this review, we illustrate and discuss the complexity in the combinatorial control of plant specialized metabolism. We hereby go beyond the intuitive concept of combinatorial control as exerted by modular-acting complexes of transcription factors that govern expression of specialized metabolism genes. To extend this discussion, we also consider all known hierarchical levels of regulation of plant specialized metabolism and their interfaces by referring to reported regulatory concepts from the plant field. Finally, we speculate on possible yet-to-be-discovered regulatory principles of plant specialized metabolism that are inspired by knowledge from other kingdoms of life and areas of biological research. Expected final online publication date for the Annual Review of Cell and Developmental Biology, Volume 36 is October 6, 2020. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

The Heat Shock Protein 40-Type Chaperone MASH Supports the Endoplasmic Reticulum-Associated Degradation E3 Ubiquitin Ligase MAKIBISHI1 in Medicago truncatula

“…Jasmonates (JA) are oxylipin-derived phytohormones that trigger defense responses upon biotic stresses, confer tolerance to abiotic stresses, and regulate various developmental cues. One of those defense responses consists of the elicitation of the biosynthesis of bio-active specialized metabolites (Goossens et al, 2016b;Wasternack and Strnad, 2019;Lacchini and Goossens, 2020). Triterpene saponins (TSs), like those found in the model legume Medicago truncatula, represent one such class of defense compounds (Szakiel et al, 2011;Gholami et al, 2014) and comprise a diverse set of amphipathic molecules made up of a lipophilic aglycone backbone covalently linked to one or more sugar moieties (Thimmappa et al, 2014).…”

Untargeted metabolomic analyses reveal the diversity and plasticity of the specialized metabolome in seeds of differentCamelina sativagenotypes

“…Specialized metabolites play crucial physiological and ecological roles throughout the plant life cycle. They can protect plants against abiotic stresses such as drought, high or low temperatures, toxic metals and UV, and can constitute effective defences against biotic stresses such as pathogens, herbivores or plant competitors (Delgoda and Murray, 2017; Corso, Perreau, Mouille, et al ., 2020; Lacchini and Goossens, 2020; Kosmacz et al ., 2020; Lepiniec et al ., 2006; Li et al ., 2020; Tohge et al ., 2016). For example, SMs can act as phytoalexins in response to pathogens, antifeedants against herbivory or allelopathic compounds to stunt the germination/growth of other plants (Corso, Perreau, Mouille, et al ., 2020; Corso, Perreau, Rajjou, et al ., 2020).…”

Molecular mechanisms involved in functional macroevolution of plant transcription factors

“…These cases highlight to what extent the differences in secondary metabolism of bryophytes and Arabidopsis were accompanied by rewiring the associated GRN. The evolution of species-specific metabolic pathway was also observed in vascular plants, and involved the acquisition of CRE in key enzyme genes(Lacchini & Goossens, 2020).There are other environment-responsive TFs that evolved different functions in different plant lineages, such as the Marchantia MYC1-homolog MpBHLH12 (Arai et al, 2019) and class I HD-Zip (MpC1HDZ)…”