From a danger signal to the biosynthesis of novel phenolic compounds
04/02/2025
Plant cell wall is an extracellular matrix composed of polysaccharides, polyphenols and proteins. The enzymatic hydrolysis of cell wall polysaccharides results in the production of oligosaccharides with nature of damage-associated molecular patterns (DAMPs) that are perceived by plants as danger signals1. Oligosaccharide-oxidases (OSOXs), flavoenzymes belonging to the sub-family of “berberine bridge enzyme-like proteins”, oxidize these oligosaccharides by quenching their DAMP action and concomitantly converting molecular O2 into H2O2 2-4. Here we show a novel reaction mechanism through which the oxidizing activity on short oligosaccharides, instead of producing H2O2, led to the reduction of oxidized phenols (bi- phenoquinones), highlighting a possible application of OSOXs in synthetic biology5. By combining the oxidative-polymerizing activity of metalloenzymes on simple phenolics and the reducing activity of OSOXs on bi-phenoquinones, we succeeded at synthetizing a variety of novel oligo-phenols potentially exploitable in different industrial sectors.
Keywords: plant cell wall, DAMPs, oligosaccharide oxidase, bi-phenoquinone, oligo-phenols, synthetic biology.
1 Benedetti et al., 2015. doi: 10.1073/pnas.1504154112
2 Benedetti et al., 2018. doi: 10.1111/tpj.13852
3 Locci et al., 2019. doi: 10.1111/tpj.14237
4 Costantini et al., 2024. doi: 10.1093/plphys/kiad457
5 Giovannoni et al., 2025. doi: 10.1016/j.plaphy.2024.109466
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