Re-engineering Plant Phenylpropanoid Metabolism With the Aid of Synthetic Biosensors

Abstract

Phenylpropanoids comprise a large class of specialized plant metabolites with many important applications, including pharmaceuticals, food nutrients, colorants, fragrances, and biofuels. Therefore, much effort has been devoted to manipulating their biosynthesis to produce high yields in a more controlled manner in microbial and plant systems. However, current strategies are prone to significant adverse effects due to pathway complexity, metabolic burden, and metabolite bioactivity, which still hinder the development of tailor-made phenylpropanoid biofactories. This gap could be addressed by the use of biosensors, which are molecular devices capable of sensing specific metabolites and triggering a desired response, as a way to sense the pathway’s metabolic status and dynamically regulate its flux based on specific signals. Here, we provide a brief overview of current research on synthetic biology and metabolic engineering approaches to control phenylpropanoid synthesis and phenylpropanoid-related biosensors, advocating for the use of biosensors and genetic circuits as a step forward in plant synthetic biology to develop autonomously-controlled phenylpropanoid-producing plant biofactories.

Lanthanum-based nanomaterials suppress bacterial wilt in tomato: importance of particle morphology and dissolution profiles

“…Additionally, metabolism of l -phenylalanine could produce flavonoids and polyphenols, and these analytes also play an important role in plant host and pathogen interaction. 52–54 The relative abundance of flavonoids (quercetin and rutin) and polyphenols (caffic acid and chlorogenic acid) was significantly increased by 14.6–40.2% and 13.7–44.8% after La based NMs application, respectively (Fig. 5C).…”

Lanthanum Silicate Nanomaterials Enhance Sheath Blight Resistance in Rice: Mechanisms of Action and Soil Health Evaluation

“…As compared with La 10 Si 6 O 27 NPs, La 10 Si 6 O 27 NRs resulted in more lignin biosynthesis, which could be attributed to the higher lignin monomer content and activity of POD in rice after La 10 Si 6 O 27 NR application. Additionally, flavonoids and polyphenols generated by phenylalanine metabolism also have a critical role in the interaction between plant host and pathogen. − Flavonoids (naringenin, rutin, and sakuranetin) were significantly increased by 222.4, 253.3, and 56.2% after La 10 Si 6 O 27 NR application compared to infected controls (Figures A and S15), which possess antioxidative and antimicrobial properties to mitigate the damage induced by pathogen infection . Polyphenols can also be an antioxidative agent in plants .…”

Genetically encoded Boolean logic operators to sense and integrate phenylpropanoid metabolite levels in plants

“…This strategy enables the organism to adjust bioproduction "on-the-fly" according to environmental cues and intracellular changes, without external interference (Gao et al, 2019). Nonetheless, some optimization may be required, including expanding the biosensors repertoire with other characterized aTFs that sense different plant metabolites (Garagounis et al, 2021;Ferreira & Antunes 2021), or by building chimeric aTFs through DBD and LBD swapping (Dimas et al, 2019) to create new ligand-RE pairs. The additional aTFs could thus sense several key intermediates of the pathway, allowing logic gates to be layered to compute multiple (>2) inputs, and leading to the development of more robust circuits, i.e., with a lower probability of unwanted activation of the output.…”