Barley nepenthesin HvNEP-1 enhances the resistance to Gibberella ear rot and Fusarium ear rot in maize

Gibberella ear rot (GER) and Fusarium ear rot (FER) are fungal diseases that cause substantial yield and quality losses. The endosperm-specific expression of barley nepenthesin 1 (HvNEP-1) conferred Fusarium head blight resistance in barley. Here, we overexpressed HvNEP-1 in the maize endosperm. Agrobacterium tumefaciens-mediated transformation generated 11 independent transgenic events (14 T0 plants) and 19 T1 transgenic lines (OE’s) after backcrossing to the WT. HvNEP-1 was significantly expressed in the seeds and silk tissues of the OE’s. The OE and non-transformed (NT) wild-type (WT) plants showed insignificant differences in plant height, number of ears and thousand kernel weight (TKW) in both the GER and FER studies. However, the ears of OE’s had significantly lower GER and FER infection rates than the NT/WT ears. Moreover, seeds of NT/WT contained substantially higher contents of DON and NIV toxins than the OE seeds. This study highlights the potential of HvNEP-1 for controlling fungal diseases in crops.