Class III Peroxidases PRX01, PRX44, and PRX73 Control Root Hair Growth in Arabidopsis thaliana

• Published in: International journal of molecular sciences Vol. 23; no. 10; p. 5375
• Main Authors: Marzol, Eliana, Borassi, Cecilia, Carignani Sardoy, Mariana, Ranocha, Philippe, Aptekmann, Ariel A, Bringas, Mauro, Pennington, Janice, Paez-Valencia, Julio, Martínez Pacheco, Javier, Rodríguez-Garcia, Diana R, Rondón Guerrero, Yossmayer Del Carmen, Peralta, Juan Manuel, Fleming, Margaret, Mishler-Elmore, John W, Mangano, Silvina, Blanco-Herrera, Francisca, Bedinger, Patricia A, Dunand, Christophe, Capece, Luciana, Nadra, Alejandro D, Held, Michael, Otegui, Marisa S, Estevez, José M
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 11.05.2022; MDPI
• Subjects: Arabidopsis; Arabidopsis - genetics; Arabidopsis Proteins - chemistry; Arabidopsis Proteins - genetics; Cell Wall; Cell walls; class-III peroxidases; extensins; Fluorescence; Glycoproteins; Hair cells; Homeostasis; Hydroxyproline; Mutation; Nutrients; Peroxidase; Peroxidases - genetics; Plant Roots - genetics; Polysaccharides; root hairs; ROS; Soil conditions; Wall thickness; extensins; class-III peroxidases; root hairs; Arabidopsis; ROS; cell walls
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms23105375

Root hair cells are important sensors of soil conditions. They grow towards and absorb water-soluble nutrients. This fast and oscillatory growth is mediated by continuous remodeling of the cell wall. Root hair cell walls contain polysaccharides and hydroxyproline-rich glycoproteins, including extensins (EXTs). Class-III peroxidases (PRXs) are secreted into the apoplastic space and are thought to trigger either cell wall loosening or polymerization of cell wall components, such as Tyr-mediated assembly of EXT networks (EXT-PRXs). The precise role of these EXT-PRXs is unknown. Using genetic, biochemical, and modeling approaches, we identified and characterized three root-hair-specific putative EXT-PRXs, PRX01, PRX44, and PRX73. triple mutation and PRX44 and PRX73 overexpression had opposite effects on root hair growth, peroxidase activity, and ROS production, with a clear impact on cell wall thickness. We use an EXT fluorescent reporter with contrasting levels of cell wall insolubilization in and PRX44-overexpressing background plants. In this study, we propose that PRX01, PRX44, and PRX73 control EXT-mediated cell wall properties during polar expansion of root hair cells.