About this Research Topic
Phenylpropanoids are a major component of specialized metabolism in plants and contribute to several aspects of plant growth and development, as well as responses to environmental stimuli. The phenylpropanoid pathway provides lignin, suberin, and condensed tannins for structural support and physical stability, flavonols and flavones for UV protection, anthocyanins for pigmentation, various flavonoids and isoflavonoids for plant-microbe interactions, and antimicrobial phytoalexins for protection against certain pathogens. Key intermediates from the shikimate pathway are structurally diversified by the combined activities of reductases, oxygenases and transferases, to generate diverse phenylpropanoids that accumulate in organ- and developmental-specific patterns. Beyond their physiological functions in planta, phenylpropanoids are also economically important. Several phenylpropanoids are considered high-value biochemicals for industrial applications, including the production of fragrances, pharmaceuticals and biopolymers. In addition, phenylpropanoids constitute important dietary components exhibiting chemopreventive, antimitotic, neuroprotective, cardioprotective, anti-inflammatory, and antioxidant activities. Meanwhile, the phenylpropanoid pathway is also a crucial step in the synthesis of monolignols, the building blocks of lignin, which is a major contributor to biomass recalcitrance and low cost biofuel production.
Recently, systems biology approaches have enabled the identification and characterization of numerous genes, enzymes and metabolites participating in phenylpropanoid metabolism in several plant species. However, there is still much to be explored and determined in terms of regulation, biosynthesis de novo, transport, compartmentation, and polymerization of such metabolites. In addition to their complex biosynthetic machinery and magnificent chemical diversity, another challenge is that some metabolite profiles are dependent on tissue type, developmental stage, plant species, or might be triggered in response to specific environmental conditions. The expanding development of “omics” technologies provides a timely opportunity to further detect and characterize even subtle changes in the levels of transcripts, enzymes and metabolites, and thus to provide a comprehensive and systems view of phenylpropanoid metabolism throughout plant development and during stress responses. Finally, unravelling key aspects of this important branch of specialized metabolism is essential to generate more resilient and nutritious crops, to maximize our arsenal of useful biomolecules, and to re-design high-yield and sustainable biofuel feedstocks by means of biotechnology.
This Research Topic aims to gather recent findings in all aspects of phenylpropanoid metabolism gained by means of systems biology approaches and the utilization of biotechnology to exploit the economic, medicinal and nutraceutical potential of phenylpropanoids. Whereas all types of articles are welcome, we particularly encourage the submission of Original Research, Reviews, Minireviews and Perspectives focusing on the following topics:
• Structural and functional characterization of enzymes involved in phenylpropanoid biosynthesis de novo
• Discovery of genes and/or gene networks involved in distinct aspects of phenylpropanoid metabolism via large-scale transcriptomics, proteomics, metabolomics, and/or any other omics technology, together with relevant functional characterization
• Functional genomics of genes involved in phenylpropanoid metabolism and its coordination with physiological processes
• Computational approaches towards unravelling the complex, and often branched, biosynthetic pathways involved in diverse phenylpropanoid-derived metabolites
• Biotechnological approaches to exploit the economic, medicinal, and nutraceutical potential of phenylpropanoids
• Targeted biodesign strategies to optimize lignocellulosic biomass composition and structure for enhanced lignin utilization and lignin valorization.
• Studies defining gene families or descriptive collection of transcripts, proteins, or metabolites, will not be considered for review unless they are expanded and provide mechanistic and/or physiological insights into the biological system or process being studied.
• Descriptive studies that report responses to a given treatment will not be considered if they do not progress physiological understanding of these responses.
Keywords: Phenylpropanoid, specialized metabolism, bioengineering, network, lignin
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.