NSF Award
2414183
Heat waves, especially when occurring during periods of drought, can have a devastating impact on agricultural production in the US. Such combinations of drought and heat waves, that occurred during the summers of 1980, 1988, 2000, and 2008 in the US, for example, resulted in yield losses estimated at 33, 44, 7.6, and 8.6 billion dollars, respectively. As episodes of drought and heat stress combination are expected to increase in their intensity and frequency in the coming years, due to the largely unopposed process of global warming, and its impacts on climate change, breeding crops with enhanced tolerance to heat stress, or a combination of water deficit and heat stress, is of the utmost importance for modern agriculture and food sustainability and security. The overall goal of this proposal is to increase yield of crop plants under conditions of heat stress, and heat stress combined with other stresses, such as drought, by enhancing the process of plant cooling, and especially the cooling of plant tissues involved in grain production (i.e., flowers and pods). The investigators recently discovered the first mechanism that allows plants to cool their flowers and seed pods under conditions of heat stress/heat stress combined with water deficit and termed it ‘differential transpiration’. The researchers' goal is to augment this process and enhance the ability of crop plants, such as soybean, to generate seeds under conditions of heat and drought combined with a heat wave. In addition, the project will provide training for postdoctoral fellows, undergraduate students and high school students. The investigators will also reach thousands of K-12 students and members of the public through hands-on outreach opportunities such as Wheels of Science, field days at the MU Bradford Research Center and South Farm, and a yearly workshop on ‘Stress combination and plant responses to the environment’. Finally, the investigators will also develop online tutorials and videos that will <br/>teach students/teachers/the public about changes to our environment and their effects on agriculture.<br/><br/>The investigators recently discovered a key mechanism that allows plants to cool their reproductive organs under conditions of heat stress/heat stress combined with water deficit, termed ‘differential transpiration’. Their working hypothesis is that manipulating the expression/function of stomata-specific genes/pathways/networks to enhance the number of stomata, and/or the degree of stomatal opening, specifically in sepals, pods, and other reproductive organs of the plant, thereby augmenting differential transpiration, will enable plants to cool their reproductive organs under stress conditions that involve heat stress/heat stress combined with other stresses that cause overall stomatal closure (e.g., eO3, pathogen infection, eCO2, and/or high irradiance). The project has 3 specific aims are: 1. Conduct an integrated phenotypic, physiological, and single-cell RNA/ATAC-sequencing analysis of flowers, pods, and leaves from soybean plants subjected to control, water deficit, heat stress, and a combination of water deficit and heat stress, with a focus on guard cells. 2. Use existing as well as develop and use new machine learning/computational tools and pipelines to analyze single-cell RNA/ATAC-sequencing datasets, integrate them with phenotypic/physiological data of soybeans subjected to stress/stress combination, conduct regulatory network and pathway analyses, and identify key transcriptional regulators and their DNA binding elements. 3. Based on the results obtained in Aims 1 and 2, use synthetic biology tools to develop transgenic soybean plants with enhanced differential transpiration and resilience to heat stress, as well as a combination of water deficit and heat stress to meet the goal of increasing the yield of crop plants under conditions of heat stress, and heat stress combined with other stresses, by enhancing the process of reproductive organ cooling.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
