Baculovirus expression of the maize mitochondrial protein URF13 confers insecticidal activity in cell cultures and larvae

The T-urf13 gene, which encodes the URF13 protein in the mitochondria of male-sterile maize carrying the Texas cytoplasm (cms-T), was cloned in a baculovirus expression system. URF13 interacts with fungal T toxin or methomyl to permeabilize the plasma membranes of insect cells. In addition, URF13 is toxic when expressed in either cell cultures or insect larvae, even without T toxin or methomyl. The results indicate that male sterility and toxin sensitivity in cms-T maize may be due to independent mechanisms.