The Respiratory Burst Oxidase Homologue OsRBOHE is crucial for root hair formation, drought resistance and tillering in rice

• Published in: Plant, cell and environment Vol. 48; no. 1; pp. 65 - 80
• Main Authors: Zhao, Xing‐Yu, Wang, Han‐Qing, Shi, Wen, Zhang, Wen‐Wen, Zhao, Fang‐Jie
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.01.2025
• Subjects: Aerobic conditions; biogenesis; Buds; Cell walls; Drought; Drought Resistance; drought tolerance; Droughts; environment; Epidermis; Gene Expression Regulation, Plant; Gene Knockout Techniques; Genes; NADPH Oxidases - genetics; NADPH Oxidases - metabolism; Oryza - enzymology; Oryza - genetics; Oryza - growth & development; Oryza - physiology; Oxidase; oxidoreductases; phosphorus; Phosphorus - metabolism; Plant growth; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Roots - genetics; Plant Roots - growth & development; Plant Roots - metabolism; Plant Roots - physiology; plasma membrane; Reactive oxygen species; reactive oxygen species (ROS); Reactive Oxygen Species - metabolism; respiratory burst; Respiratory burst oxidase; Rice; root epidermis; Root hairs; soil; Soil resistance; tillering; reactive oxygen species (ROS); root hairs; phosphorus
• ISSN: 0140-7791; 1365-3040; 1365-3040
• DOI: 10.1111/pce.15114

Respiratory Burst Oxidase Homologues (RBOHs) are involved in plant growth, development, and stress adaptation. How OsRBOHs affect root hair formation and consequently nutrient acquisition and drought resistance in rice is not well understood. We knocked out six OsRBOH genes in rice that were expressed in roots and identified OsRBOHE as the only one affecting root hair formation. OsRBOHE was strongly expressed in the root epidermis, root hairs and tiller buds. OsRBOHE is localised at the plasma membrane. Knockout of OsRBOHE decreased reactive oxygen species generation in the root hairs and tiller buds, downregulated genes involved in cell wall biogenesis, and decreased root hair length and tillering by 90% and 30%, respectively. Knockout of OsRBOHE decreased phosphorus acquisition only in low available P soil under aerobic conditions, but not in high P soil or under flooded conditions when P was likely not limited by diffusion. Knockout of OsRBOHE markedly decreased drought resistance of rice plants through the effect on root hair formation and the associated rhizosheath. Taken together, OsRBOHE is crucial for root hair formation and tillering and consequently on drought resistance in rice. The contribution of root hairs to P acquisition in rice is limited to aerobic soil. Summary statement The Respiratory Burst Oxidase Homologues OsRBOHE is crucial for root hair formation and tillering and consequently on drought resistance and grain yield in rice. The contribution of root hairs to phosphorus acquisition in rice is limited to low P soil under aerobic condition.