Determining Maize Gene Expression Response to Sustainable and Conventional Soil Management Systems.

Maize geneticists have yet to address the question of how agronomic practices affect gene expression and how this knowledge can be used to improve crop response to sustainable agricultural systems. This project contrasts effects of sustainable and conventional soil management practices on gene expression in maize.  The “sustainable” management system utilizes hairy vetch as a legume cover crop and no-tillage while the “conventional” system does not utilize a cover crop and includes moldboard tillage.  Sustainable and conventional soil management systems expose maize plants to different growing conditions such as soil moisture, source and amount of available nitrogen, and root-zone temperature.  We expected that expression of genes controlling carbon and nitrogen metabolism, pest and disease defense, senescence, and drought and cold stress tolerance would vary between soil management systems.  Gene expression in leaf tissue was analyzed using quantitative real-time PCR, and plant growth and soil properties were monitored throughout the growing season.  Preliminary results show significant treatment effects of tillage type, cover crop, and fertilizer rate on expression of genes involved in carbon and nitrogen metabolism as well as on genes involved in response to environmental stress.  These results can be used to help explain some of the differences in final yield and plant health recorded throughout the season. This research will help scientists and farmers better understand the effects of well characterized sustainable agricultural practices from a new perspective with a molecular emphasis.  The findings from this study could also provide important information for plant breeders who wish to develop maize plants that excel under conditions experienced in sustainable management systems.