TiO ₂ nanomaterial promotes plant growth and disease resistance

TiO₂ nanomaterials can promote plant growth and enhance disease resistance. However, the underlying mechanism remains unclear. This study applied TiO₂ to promote the growth of wheat, soybean, tobacco, cucumber, and corn. Genetic analysis using macro-element transporter rice mutants in rice revealed that growth promotion induced by TiO₂ was dependent on <i>potassium transporter</i> (<i>AKT1</i>), <i>nitrate transporter 1.1B</i> (<i>NRT1.1B</i>), <i>ammonium transporter 1</i> (<i>AMT1</i>), and <i>phosphate transporter 8</i> (<i>PT8</i>). TiO₂ also enhanced chlorophyll accumulation, and growth promotion was inhibited in the chlorophyll biosynthesis rice mutants, <i>yellow-green leaf 8</i> (<i>ygl8</i>) and <i>divinyl reductase</i> (<i>dvr</i>), indicating that TiO₂ promoted growth through chlorophyll biosynthesis. In addition to photosynthesis, TiO₂ affected light signaling by inhibiting the translocation of Phytochrome B (<i>PhyB</i>) from the cytosol to the nucleus, thereby improving resistance to rice sheath blight (ShB). TiO₂ application also enhanced resistance to wheat stem rust, tobacco wildfire, angular spot disease, and rice ShB by inhibiting the growth of bacterial and fungal pathogens, suggesting that TiO₂ regulates plant defense signaling and has antibacterial and antifungal effects. Field experiments with wheat, soybeans, and rice confirmed that TiO₂ treatment significantly increased the crop yield. These findings suggest that TiO₂ is a promising nanomaterial for the simultaneous enhancement of plant growth and disease resistance.