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

MARZOL, ELIANA; BORASSI, CECILIA; SARDOY, MARIANA CARIGNANI; RANOCHA, PHILIPPE; APTEKMANN, ARIEL A.; BRINGAS, MAURO; PENNINGTON, JANICE; PAEZ-VALENCIA, JULIO; PACHECO, JAVIER MARTÍNEZ; RODRÍGUEZ-GARCIA, DIANA R.; GUERRERO, YOSSMAYER DEL CARMEN RONDÓN; 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.

International Journal of Molecular Sciences

MDPI

Año: 2022 vol. 23

1661-6596

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. prx01,44,73 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 prx01,44,73 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.