Maghemite Nanoparticles Acts as Nanozymes, Improving Growth and Abiotic Stress Tolerance in Brassica napus.

Yttrium doping-stabilized γ-FeO nanoparticles were studied for its potential to serve as a plant fertilizer and, through enzymatic activity, support drought stress management. Levels of both hydrogen peroxide and lipid peroxidation, after drought, were reduced when γ-FeO nanoparticles were delivered by irrigation in a nutrient solution to Brassica napus plants grown in soil. Hydrogen peroxide was reduced from 151 to 83 μM g compared to control, and the malondialdehyde formation was reduced from 36 to 26 mM g. Growth rate of leaves was enhanced from 33 to 50% growth compared to fully fertilized plants and SPAD-measurements of chlorophyll increased from 47 to 52 suggesting improved agronomic properties by use of γ-FeO nanoparticles as fertilizer as compared to chelated iron.