A maize gene coding for a chimeric superlectin reduces growth of maize fungal pathogens and insect pests when expressed transgenically in maize callus

Plant breeding for pest resistance is a long process, and the rate of development of resistant varieties would be accelerated if resistance genes to multiple pests could be identified. A gene located in a resistance locus was cloned from a maize inbred with resistance to Fusarium spp. pathogens. This gene codes for an unusual lectin with regions of high histidine and proline frequency and two apparent sugar binding moieties. Binding studies with yeast-produced versions indicated N-acetyl glucosamine residues are a likely target. When the gene was expressed transgenically in maize callus, reduced growth of pathogenic Fusarium species (up to 71%) and caterpillar pests (up to 65%) was noted compared to control transformants, and the degree of growth inhibition was associated with levels of the protein detected. Available sequence of the gene from other maize inbreds indicated it was often disrupted and likely to code for proteins with reduced function. Incorporation of functional versions of the gene into crops will likely assist with sustainable crop production by promoting enhanced pest resistance.