Collaborative Research: RUI: RESEARCH-PGR Meeting Future Food Demands: Phosphoproteomics to Unravel Signaling Pathways in Soybean's Response to Phosphate and Iron Deficiency

California State University, East Bay Foundation, Inc., Hayward CA

Investigators

Abstract

Soybean is an important crop in the US and worldwide, grown primarily for its oil and as a food source. Soybean crop yield is critical for the US and global economy, but iron and phosphate deficiencies are common problems in many US soybean-growing regions, and this can severely limit soybean production. This problem is exacerbated by the fact that phosphate is a finite resource, and we are at risk of running out of accessible (minable) rock phosphate fertilizer within centuries. The objective of the proposed research is to understand how soybean senses and immediately responds to phosphate and iron deficiencies. Our approach is based on a technique called quantitative phosphoproteomics which has been successfully applied to identify other signaling pathways in plants but has not yet been applied to phosphate or iron deficiency signaling. A better understanding of early responses to two major nutrient stresses could help to develop soybean lines with reduced need for fertilizers. The project will directly impact undergraduate and master students in Science, Technology, Engineering, and Mathematics by providing experience in hands-on research and dissemination. This in turn will help students, mostly belonging to underrepresented minority groups, to obtain employment in the local biotech industry. Avoiding a food crisis is one of the greatest challenges facing the world today, requiring crops with improved uptake and utilization of nutrients. Phosphate and iron deficiencies limit soybean production in the US and worldwide. Although significant research has been devoted to identifying plant responses to phosphate and iron deficiency, far less is known about how plants sense and signal these deficiencies. This is because most experimental approaches have focused on changes in gene expression. However, signal transduction components, while usually not differentially expressed, are frequently differentially phosphorylated. We will apply quantitative phosphoproteomics to soybeans to identify differentially phosphorylated proteins in response to short-term phosphate and iron deficiency. We will then confirm potential signaling roles by generating RNAi knockdown mutants and analyzing these for impaired nutrient signaling responses. While quantitative phosphoproteomics has been successfully applied to unravel other signal transduction pathways in plant stress responses, it has not yet been applied to phosphate or iron deficiency signaling. The proposed research will help bridge the gap between known loci and genes involved in nutrient tolerance in soybeans and the underlying signaling pathways. In the long term, a better understanding of signal transduction and networks integrating various nutrient stress responses could aid system-based approaches to breed or bioengineer soybeans with increased stress tolerance, productivity, and reduced need for fertilizers. Our educational objective is to train undergraduate and graduate students, most belonging to underrepresented minority groups in STEM, in hands-on research and dissemination. 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.