Periodic Reporting for period 3 - INSPIRE (System-wide discovery and analysis of inositol pyrophosphate signaling networks in plants)
Reporting period: 2022-06-01 to 2023-11-30
The growth and development of plants is strongly influenced by environmental conditions, such as the availability of nutrients. The InsPire project studies how small molecule nutrient messengers called inositol pyrophosphates communicate with developmental and immune signaling pathways, enabling the plant to shape its growth and development in response to changes in nutrient availability. Since many nutrients are poorly available in soils understanding plant nutrient sensing and signaling may be of biotechnological relevance. Specifically, the project aims at understanding at the mechanistic and physiological level how a) inositol pyrophosphates are broken down in plants, b) how they regulate different light signaling and developmental pathways and c) how they modulate the function of the plant immune system.
A small molecule interaction screen has yielded a large number of plant proteins, that may bind inositol pyrophosphates. We have tested for selected protein candidates if that indeed happens in a test tube, and if the nutrient messenger can affect the function of the protein. We have visualized where and how the nutrient messengers binds to different proteins, and we have begun to study what happens if we block these binding sites in a model plant. Using this approach, we have defined two types of enzymes that can break down inositol pyrophosphates in plants, two families of protein kinases that can regulate various developmental processes and a family of immune signaling proteins. We are currently working to understand how inositol pyrophosphates regulate these different proteins in cells, and what cellular functions they can influence.
Until the end of the project, we hope to define a signaling web in plants that enables small nutrient messengers to regulate the activity of many different target proteins, which together shape the plant’s response to changing nutrient conditions.