Location: Crop Bioprotection ResearchTitle: Validation of candidate maize insect and fungal resistance genes through functional analysis
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/15/2019
Publication Date: 5/20/2019
Citation: Dowd, P.F., Naumann, T.A., Johnson, E.T., Berhow, M.A., Zilkowski, B.W., Muturi, E.J. 2019. Validation of candidate maize insect and fungal resistance genes through functional analysis. Meeting Abstract.
Technical Abstract: Sustainable production of maize and other crops is negatively impacted by insect and fungal pests, which can also produce toxins harmful to people and animals. Enhanced plant resistance to these pests is a useful strategy for enhancing production, but identification of appropriate resistance genes is challenging due to the postulated multigenic nature of resistance. Potential resistance gene candidates often located in quantitative trait loci associated with maize ear rot resistance, were determined based on annotated functionality found in databases (which was not always correct), cloned from resistant inbreds, and expressed in maize callus and yeast expression systems. Purified yeast-produced proteins and transformed maize callus were evaluated for effects on maize ear fungal and insect pests, and commercial strains for insect biocontrol fungi. Many examples increased resistance to both insects and fungi. All genes were previously unexamined and included those that produced hydrolytic enzymes (chitinase, chitinase-like, glucanase), altered secondary metabolite production (geranylgeranyl transferase, chalcone isomerase 3), or potentially affected multiple targets (thionin, regulatory protein). Many that were active against ear rot fungi also inhibited the growth of an insect fungal pathogen. Thus, postulated multigenic involvement is demonstrated with functionality assays, but presents a challenge in selecting the appropriate gene complex for introduction or editing without impacting nontarget organisms.