Varying weed densities alter the corn transcriptome, highlighting a core set of weed-induced genes and processes with potential for manipulating weed tolerance

Authors: Horvath, David; CLAY, SHARON - South Dakota State University; BRUGGEMAN, STEPHANIE - Augustana University; Anderson, James; Chao, Wun; Yeater, Kathleen

Submitted to: The Plant Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/6/2019
Publication Date: 11/1/2019
Citation: Horvath, D.P., Clay, S.A., Bruggeman, S.A., Anderson, J.V., Chao, W.S., Yeater, K.M. 2019. Varying weed densities alter the corn transcriptome, highlighting a core set of weed-induced genes and processes with potential for manipulating weed tolerance. The Plant Genome. 12(3):1-9. https://doi.org/10.3835/plantgenome2019.05.0035.
DOI: https://doi.org/10.3835/plantgenome2019.05.0035

Interpretive Summary: Weeds reduce the potential yield of crops just by growing near the crop plant - even before competition for resources such as light, nutrients, or water occurs. How a crop “sees” the weed, and how the crop reduces its growth in response, is poorly understood. We examined all genes of corn and identified ten genes that were turned on or off when corn plants were grown with a weed using corn and winter canola as a model for crop-weed interactions. These genes will help us find ways to make crops blind to weeds, thereby reducing crop yield losses caused by weeds.

Technical Abstract: Phenological responses of corn to competition with increasing densities of winter canola as the weedy competitor were investigated. Changes in the corn transcriptome due to varying weed densities were used to identify genes and processes responsive to competition under controlled conditions where light, nutrients, and water were not limited. Although increasing densities of weeds resulted in decreased corn growth and development, it increased the number and expression intensity of competition-responsive genes. The physiological processes identified in corn that were consistently induced by competition with weeds included protein synthesis, and various transport functions. Likewise, numerous genes involved in these processes, as well as several genes implicated in phytochrome signaling and defense responses, were noted as differentially expressed. The results obtained in this study, conducted under controlled (greenhouse) conditions, were compared to a previously published study where the response of corn to competition with other species was evaluated under field conditions. Approximately a 3rd of the genes were differentially expressed in response to competition under both field and controlled conditions. These competition-responsive genes represent a resource for investigating signaling processes by which corn recognizes and responds to competition. These results also highlight specific physiological processes that might be targets for mitigating the response of crops to weeds or other competitive plant under field conditions.