Abstract
TiO(2) nanomaterials can promote plant growth and enhance disease resistance. However, the underlying mechanism remains unclear. This study applied TiO(2) 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 TiO(2) was dependent on potassium transporter (AKT1), nitrate transporter 1.1B (NRT1.1B), ammonium transporter 1 (AMT1), and phosphate transporter 8 (PT8). TiO(2) 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 TiO(2) promoted growth through chlorophyll biosynthesis. In addition to photosynthesis, TiO(2) 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). TiO(2) 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 TiO(2) regulates plant defense signaling and has antibacterial and antifungal effects. Field experiments with wheat, soybeans, and rice confirmed that TiO(2) treatment significantly increased the crop yield. These findings suggest that TiO(2) is a promising nanomaterial for the simultaneous enhancement of plant growth and disease resistance.