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
04/02/2025
Martedì 4 febbraio 2025 alle 11.30 in Sala Parravano, ed. Chimica "Cannizzaro" (CU014).
"From a danger signal to the biosynthesis of novel phenolic compounds"
Manuel Benedetti, Università dell'Aquila, Italia