title: Cell Wall Amine Oxidases: New Players in Root Xylem Differentiation under Stress Conditions.
abstract: Polyamines (PAs) are aliphatic polycations present in all living organisms. A growing body of evidence reveals their involvement as regulators in a variety of physiological and pathological events. They are oxidatively deaminated by amine oxidases (AOs), including copper amine oxidases (CuAOs) and flavin adenine dinucleotide (FAD)-dependent polyamine oxidases (PAOs). The biologically-active hydrogen peroxide (H₂O₂) is a shared compound in all of the AO-catalyzed reactions, and it has been reported to play important roles in PA-mediated developmental and stress-induced processes. In particular, the AO-driven H₂O₂ biosynthesis in the cell wall is well known to be involved in plant wound healing and pathogen attack responses by both triggering peroxidase-mediated wall-stiffening events and signaling modulation of defense gene expression. Extensive investigation by a variety of methodological approaches revealed high levels of expression of cell wall-localized AOs in root xylem tissues and vascular parenchyma of different plant species. Here, the recent progresses in understanding the role of cell wall-localized AOs as mediators of root xylem differentiation during development and/or under stress conditions are reviewed. A number of experimental pieces of evidence supports the involvement of apoplastic H₂O₂ derived from PA oxidation in xylem tissue maturation under stress-simulated conditions.
authors.affiliation: Institute of Crystallography, Consiglio Nazionale delle Ricerche (CNR), Monterotondo 00015, Italy. sandip.ghuge.biotech@gmail.com.
authors.forename: Sandip A
authors.initials: SA
authors.lastname: Ghuge
authors.affiliation: Department of Sciences, Università Roma Tre, Roma 00146, Italy. ale1.ale2@alice.it.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Tisi
authors.affiliation: Department of Sciences, Università Roma Tre, Roma 00146, Italy. andrea.carucci@uniroma3.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Carucci
authors.affiliation: Department of Life, Health, and Environmental Sciences, Università dell'Aquila, L'Aquila 67100, Italy. pousada@univaq.it.
authors.forename: Renato A
authors.initials: RA
authors.lastname: Rodrigues-Pousada
authors.affiliation: Department of Sciences, Università Roma Tre, Roma 00146, Italy. stefano.franchi@uniroma3.it.
authors.forename: Stefano
authors.initials: S
authors.lastname: Franchi
authors.affiliation: Department of Sciences, Università Roma Tre, Roma 00146, Italy. paraskevi.tavladoraki@uniroma3.it.|Istituto Nazionale Biostrutture e Biosistemi (INBB), Rome 00136, Italy. paraskevi.tavladoraki@uniroma3.it.
authors.forename: Paraskevi
authors.initials: P
authors.lastname: Tavladoraki
authors.affiliation: Department of Sciences, Università Roma Tre, Roma 00146, Italy. riccardo.angelini@uniroma3.it.|Istituto Nazionale Biostrutture e Biosistemi (INBB), Rome 00136, Italy. riccardo.angelini@uniroma3.it.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Angelini
authors.affiliation: Department of Sciences, Università Roma Tre, Roma 00146, Italy. alessandra.cona@uniroma3.it.|Istituto Nazionale Biostrutture e Biosistemi (INBB), Rome 00136, Italy. alessandra.cona@uniroma3.it.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Cona
keywords: amine oxidases; cell wall; hydrogen peroxide; polyamines; root; xylem differentiation