ERA-CAPS: Collaborative Research: Thylakoid ion flux-Linking photosynthetic efficiency with osmotic stress response

Michigan State University, East Lansing MI

Investigators

Abstract

Plant productivity is dependent on many environmental factors, whether plants grow wild or are carefully cultivated in a farmer's field. Efficient photosynthesis is the key to plant productivity, but soil salinity disrupts electrolytes, the so-called ion balance, in the leaf cells where photosynthesis occurs. Soil salinity is a growing problem globally and will affect worldwide food supplies if not effectively controlled. Deciphering how a plant responds to salinity and regulates its cellular ion fluxes is essential to understanding and potentially improving photosynthesis. This project identifies specific genes that control ion fluxes and responses to salinity in plants using a specialized imaging system and analysis tools to study their role in plant productivity. The international team will use their findings to develop a computational model to inform and improve breeding programs and to develop more highly productive plants that can tolerate soil salinity. The model will be tested in tomato with potential to have broad impact to assure global food security. Ion flux across the thylakoid membrane represents a promising target for improving plant photosynthesis, yet knowledge of key components is far from complete. This project brings together an international consortium with complementary expertise in chloroplast ion flux, spectroscopy, phenotyping, ionomics, biochemistry, bioenergetics, and computational modelling. By pursing multi-day phenotyping with dynamic growth lighting, the team has isolated new candidate thylakoid ion flux mutants. The researchers will study the compromised genes and their link to known thylakoid ion flux mediators by pursuing the following aims: (i) complete the thylakoid ion transport protein inventory; (ii) determine the role of thylakoid ion flux interactions in photosynthesis and hyperosmotic stress resistance; (iii) identify the process by which thylakoid ion flux impacts the hyperosmotic stress response; (iv) analyze thylakoid ion flux impacts on key agronomical traits in crop plants; and (v) generate a model for simulating increases to photosynthetic efficiency and salt stress resistance as a function of thylakoid ion flux. The Flux4LIVES project has several broader impacts. Photosynthesis is arguably the most important reaction on earth and a foundation for life. With clear evidence that growth conditions in the field have become more adverse recently, a detailed understanding on how abiotic stress impacts this reaction pathway is needed. Understanding the molecular mechanisms that protect photosynthesis and plant productivity will be key to improving these pathways and thus securing necessary levels of global food production. Since the data obtainedwill be open-access via the existing PhotosynQ database, the global scientific community can apply the knowledge to their own biological and ecological questions and thus further the effort to meet food demands across varying climates and conditions. 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.