CAREER: Determine the function of plasmodesmata as redox signaling hubs

Iowa State University, Ames IA

Investigators

Abstract

Plants are composed of millions of cells and intercellular signaling is essential for their physiology, especially under adverse growth conditions. Given the substantial environmental challenges climate change presents, there is an urgent need to understand how plants regulate cell-to-cell communication to adapt to changing environments. This project will explore the function and regulation of plant cell-to-cell communication systems. To communicate, plant cells utilize membrane-lined channels that connect adjoining cells. This research will investigate the function of these channels as hubs for reactive oxygen species signaling. Reactive oxygen species play a pivotal role in maintaining normal cellular processes in animals and plants, making them essential components in the health and disease of organisms. In addition, reactive oxygen species play a crucial role during plant stress responses. Unraveling the role of plant cell-to-cell communication channels as reactive oxygen species hubs holds promise for designing climate-resilient crops, crucial for safeguarding human nutrition in the face of climate change. The Broader Impacts of the project include the intrinsic nature of work as all plants have these channels. In addition, the project will involve the training of young scientists at various career stages, providing them with early exposure to life science. Middle and high school students in STEM will have opportunities to gain hands-on experience in cutting-edge cell biology research. The PI will develop a new course to educate undergraduate students, sharpening their skills in plant molecular biology techniques. Moreover, undergraduate students will receive training in utilizing artificial intelligence to study plant cell biology. Graduate students and post-doctoral researchers will also receive training. These activities will increase the number and skills of students pursuing future careers in plant biology. Multicellular organisms rely on cell-to-cell communication to exchange signals and resources for survival and adaptation. In plants, membrane-lined pores, termed plasmodesmata, connect adjoining cells. This study will investigate the regulation and function of plasmodesmata. Recent studies have highlighted that plasmodesmata-located protein 5 (PDLP5) regulates plasmodesmal function and governs plant growth and defense in Arabidopsis thaliana. Using an enzyme-catalyzed proximity labeling assay and AlphaFold-Multimer analysis, the PI’s lab identified proteins involved in producing, sensing, and transporting reactive oxygen species (ROS) as functional partners of PDLP5. The findings suggest the function of plasmodesmata as ROS signaling hubs. The project will test the central hypothesis that hydrogen peroxide sensor HPCA1 functions at plasmodesmata to regulate hydrogen peroxide transport by phosphorylating plasma membrane intrinsic proteins (aquaporins), which can transport water and hydrogen peroxide. The project will apply a multidisciplinary approach encompassing genetics, cell biology, biochemistry, structural biology, and yeast analysis. As redox regulation and cell-to-cell communication are fundamental for maintaining the health of multicellular organisms, findings from the project will contribute to improving the health of plants and humans. This project is jointly funded by the Cellular Dynamics and Function program in the Division of Molecular and Cellular Biosociences along with the Established Program to Stimulate Competitive Research (EPSCoR). 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.