Undesirable protein sequence variations in maize genes that confer resistance to fungal pathogens and insect pests

Abstract

Diseases and insect pests greatly impact sustainable production in maize. Maize inbred lines have varying levels of resistance to these pathogens and insects, but little is known about the diversity of their resistance proteins. In this study, genes encoding seven proteins that are involved in resistance to insects and pathogens in maize were analyzed in 46 maize inbred lines to elucidate the differences in amino acid sequences. The proteins of interest are superlectin, maizewin, hydrolase, geranyl geranyl transferase, quinone oxidoreductase, AIL1, and defensin. The protein sequences encoded by genes for superlectin, AIL1, and defensin were found to be disrupted in some maize inbreds but were conserved in others. The characterized disruptions resulted from single amino acid changes, insertions, or deletions. While the effect of single amino acid changes is hard to predict, insertions and deletions likely disrupt protein function, increasing the susceptibility of maize plants to insects and/or diseases. Functional resistance genes can be incorporated from the identified maize inbreds into commercial hybrids to promote enhanced insect and pathogen resistance.