title: An NADPH Oxidase RBOH Functions in Rice Roots during Lysigenous Aerenchyma Formation under Oxygen-Deficient Conditions.
abstract: Reactive oxygen species (ROS) produced by the NADPH oxidase, respiratory burst oxidase homolog (RBOH), trigger signal transduction in diverse biological processes in plants. However, the functions of RBOH homologs in rice (Oryza sativa) and other gramineous plants are poorly understood. Ethylene induces the formation of lysigenous aerenchyma, which consists of internal gas spaces created by programmed cell death of cortical cells, in roots of gramineous plants under oxygen-deficient conditions. Here, we report that, in rice, one RBOH isoform (RBOHH) has a role in ethylene-induced aerenchyma formation in roots. Induction ofRBOHHexpression under oxygen-deficient conditions was greater in cortical cells than in cells of other root tissues. In addition, genes encoding group I calcium-dependent protein kinases (CDPK5 and CDPK13) were strongly expressed in root cortical cells. Coexpression of RBOHH with CDPK5 or CDPK13 induced ROS production inNicotiana benthamianaleaves. Inhibitors of RBOH activity or cytosolic calcium influx suppressed ethylene-induced aerenchyma formation. Moreover, knockout ofRBOHHby CRISPR/Cas9 reduced ROS accumulation and inducible aerenchyma formation in rice roots. These results suggest that RBOHH-mediated ROS production, which is stimulated by CDPK5 and/or CDPK13, is essential for ethylene-induced aerenchyma formation in rice roots under oxygen-deficient conditions.
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan.
authors.forename: Takaki
authors.identifier: http://orcid.org/0000-0002-6772-6506
authors.initials: T
authors.lastname: Yamauchi
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan.
authors.forename: Miki
authors.initials: M
authors.lastname: Yoshioka
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Fukazawa
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan.
authors.forename: Hitoshi
authors.identifier: http://orcid.org/0000-0001-7331-0884
authors.initials: H
authors.lastname: Mori
authors.affiliation: Graduate School of Agricultural and Life Sciences, University of Tokyo, Bunkyo, Tokyo 113-8657, Japan.|Research Institute for Bioresources and Biotechnology, Ishikawa Prefectural University, Ishikawa 921-8836, Japan.
authors.forename: Naoko K
authors.initials: NK
authors.lastname: Nishizawa
authors.affiliation: Graduate School of Agricultural and Life Sciences, University of Tokyo, Bunkyo, Tokyo 113-8657, Japan.
authors.forename: Nobuhiro
authors.identifier: http://orcid.org/0000-0002-2610-6837
authors.initials: N
authors.lastname: Tsutsumi
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan.
authors.forename: Hirofumi
authors.identifier: http://orcid.org/0000-0003-3956-7250
authors.initials: H
authors.lastname: Yoshioka
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan nakazono@agr.nagoya-u.ac.jp.|UWA School of Agriculture and Environment, Faculty of Science, The University of Western Australia, Crawley WA 6009, Australia.
authors.forename: Mikio
authors.identifier: http://orcid.org/0000-0001-7119-2052
authors.initials: M
authors.lastname: Nakazono
mesh_terms: D064113:CRISPR-Cas Systems / Q000235:genetics / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology*; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism*; D012275:Oryza / Q000235:genetics / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D017382:Reactive Oxygen Species; D019255:NADPH Oxidases; D010100:Oxygen