Engineering Heat-Tolerant Maize

As a consequence of climate change, it is predicted that periods of agriculturally significant environmental stress conditions due to high temperatures will occur more frequently by the end of the century. These conditions are expected to pose a significant threat to global agricultural productivity and food security. In the U.S., according to a recent analysis published by the USDA-ERS [21], the widely publicized U.S. drought of 2012, with its associated high temperatures, resulted in heavy agricultural losses with respect to the corn and soybean crops. As a result of drought and high heat, the US maize harvest was nearly 13% smaller in 2012 than in 2011, in sharp contrast with an average 4.8% year-over-year increase in maize harvest size since 1983 [13]. The decreased 2012 maize harvest was blamed for food shortages and increased food prices worldwide; maize varieties with improved heat and drought tolerance will help to minimize such food shortages and price spikes. This complex environmental challenge to agriculture occurs against a background of rising global population and increased demand for the products of high intensity agriculture such as meat and dairy products. To address the current and future challenges to US agriculture, novel technology approaches are needed. Agricultural biotechnology enables the development and deployment of trait solutions in a much shorter time frame than is possible by conventional breeding approaches and is also able to access a much greater amount of genetic diversity than would be otherwise be available for crop improvement.Over the last two decades, first generation biotech traits have helped increase grain yields by protecting crops from insect pests and weeds. Benson Hill Biosystems is focusing on genetic modifications of crops designed to enhance yield potential and contribute to overall yield gains in combination with first generation traits. Environmental stress tolerance traits such as drought tolerance and heat tolerance belong to this trait category. The goal of the proposed research is to demonstrate the expression and efficacy of a heat-tolerance trait in maize resulting in improved yield following high-temperature stress. Maize will be used as the target crop for the project because it represents perhaps the greatest opportunity for the deployment of commercial heat-tolerance traits. Many of the 97 million acres planted with this crop in the US are grown ingeographies that are expected to be adversely impacted by the predicted trend toward higher average temperatures. This project will generate maize lines that will provide improved corn yields in areas where plants are subjected to elevated temperatures, thereby improving the food supply.