Nano-Priming with MnFe2O4 NMs Enhances Resistance to Drought Stress and Salt Stress in Maize

Drought and salt stress hinder the germination of maize (Zea mays L.) and delay seedling growth. With seed priming and potting experiments, our paper presented a study of the effect of priming with manganese ferrite materials (MnFe2O4 NMs) at different concentrations (20, 40, and 80 mg/L) on the seed germination and the following seedlings growth under stresses. Our results showed that seed priming with MnFe2O4 NMs increased the germination of seeds under stress conditions, remarkably, the most significant increase was for seed root length and vigor index. Moreover, the improvement of drought stress by MnFe2O4 NMs was concentration-dependent, and the 20 mg/L was optimal for mitigating both drought stress under 10% polyethylene glycol (PEG) conditions and drought stress under water control in the field. For alleviating salt stress, however, MnFe2O4 NMs were effective at every concentration, showing concentration-independence. These findings support that seed nano-priming can be a preferred option for stress mitigation, with MnFe2O4 NMs being a good choice.