Maize Terpene Synthase 1 impacts insect bahavoir via the production of monoterpene volatiles beta-myrcene and linalool

Authors: Yactayo Chang, Jessica; Broadhead, Geoffrey; HOUSLER, ROBERT - University Of Florida; RESENDE, MARICIO - University Of Florida; VERMA, KASHISH - University Of Nebraska; LOUIS, JOE - University Of Nebraska; BASSET, GILES - University Of Florida; Beck, John; Block, Anna

Submitted to: Phytochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/24/2023
Publication Date: 12/29/2023
Citation: Yactayo Chang, J.P., Broadhead, G.T., Housler, R.J., Resende, M., Verma, K., Louis, J., Basset, G.J., Beck, J.J., Block, A.K. 2023. Maize Terpene Synthase 1 impacts insect bahavoir via the production of monoterpene volatiles beta-myrcene and linalool. Phytochemistry. 2024,218,113957. https://doi.org/10.1016/j.phytochem.2023.113957.
DOI: https://doi.org/10.1016/j.phytochem.2023.113957

Interpretive Summary: Fall armyworm is a major insect pest of many agricultural crops, including corn. These moths use plant odors to locate suitable plants on which to lay their eggs. ARS scientists at the Chemistry Research Unit in Gainesville, FL in collaboration with researchers at University of Florida and University of Nebraska-Lincoln investigated how a corn gene involved in producing plant odors impacts the attractiveness of corn to fall armyworm. They showed that a loss-of-function mutant in this corn gene had lower levels of two odor compounds and was less attractive to fall armyworm caterpillars and moths than corn with a functional gene. This information can be used in molecular breeding to select corn varieties that are more difficult for fall armyworm to locate.

Technical Abstract: The insect Spodoptera frugiperda (fall armyworm) is a major global pest of Zea mays (maize) and other crops. Host location by S. frugiperda is influenced by the blend of volatile organic compounds released from host tissues, yet how individual compounds in this blend impact host selection, and what maize genes are important for this interaction are just starting to be explored. In this study we analyzed headspace volatiles from a sweetcorn diversity panel that was infested with S. frugiperda larvae and used mGWAS to identify the maize gene terpene synthase 1 (ZmTPS1) as a candidate for production of the monoterpene volatiles beta-myrcene and linalool. Analysis of volatile compounds in a maize tps1 loss-of-function mutant confirmed that ZmTPS1 is an important contributor to the production of both linalool and beta-myrcene. Furthermore, assessment of S. frugiperda larval feeding choice and oviposition preferences using pairwise choice assays between tps1 mutant and wild type plants revealed that ZmTPS1, and by extension its volatile products, are important for S. frugiperda host location.