TiO2 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 potassium transporter (AKT1), nitrate transporter 1.1B (NRT1.1B), ammonium transporter 1 (AMT1), and phosphate transporter 8 (PT8). TiO2 also enhanced chlorophyll accumulation, and growth promotion was inhibited in the chlorophyll biosynthesis rice mutants, yellow-green leaf 8 (ygl8) and divinyl reductase (dvr), indicating that TiO2 promoted growth through chlorophyll biosynthesis. In addition to photosynthesis, TiO2 affected light signaling by inhibiting the translocation of Phytochrome B (PhyB) 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.