Transgenic expression of a previously uncharacterized maize AIL1 gene in maize callus increases resistance to multiple maize fungal and insect pests

Authors: Dowd, Patrick; Johnson, Eric

Submitted to: Plant Gene
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/28/2020
Publication Date: 5/30/2020
Citation: Dowd, P.F., Johnson, E.T. 2020. Transgenic expression of a previously uncharacterized maize AIL1 gene in maize callus increases resistance to multiple maize fungal and insect pests. Plant Gene. 23:100235. https://doi.org/10.1016/j.plgene.2020.100235.
DOI: https://doi.org/10.1016/j.plgene.2020.100235

Interpretive Summary: Insects and disease greatly reduce corn yields. Corn ear molds can produce toxins harmful to people and animals, causing hundreds of millions of dollars in losses in the U.S. alone. Plant resistance is an economical means to reduce corn ear damage caused by insects and corn ear molds, but there continues to be a need to determine what genes are involved in producing resistance. A gene isolated from a chromosome region that was previously associated with ear rot resistance was evaluated for its resistance role. The gene had a postulated role as a regulatory protein. When introduced into corn cells, cell clumps that had the gene reduced growth of maize pest caterpillars and representative ear rot fungi compared to cell clumps that did not contain the gene. Analysis of the cell clumps that were active against insects and fungi indicated differences in protein presence that supported a regulatory role of the gene. This knowledge can be used to guide breeding for insect and ear rot resistance in crop plants, thereby enhancing yield, quality and safety.

Technical Abstract: Large portions of the world are dependent on maize. Maize production is limited by insect and fungal damage, and some ear rotting fungi also contaminate grain with toxins. Plant resistance is part of a sustainable strategy for maize production, but genes involved in resistance still need to be identified. A previously uncharacterized AIL1 gene located in a resistance metaQTL was cloned from a Fusarium resistant maize inbred and transgenically expressed in maize callus. Transformed callus producing the protein inhibited growth of Fusarium maize pathogens and maize feeding caterpillar pests. The degree of enhanced resistance was correlated with expression levels of the protein. Additional proteins were upregulated in the transgenic callus as predicted by prior interactome information. The identification of this newly identified resistance gene should help the production of more pest resistant maize, resulting in higher quality and safer maize for humans and animals.