CAREER: Anatomical and physiological mechanisms linking dynamic leaf water storage and damage to plants

When plants dry out, their leaves wilt. During this process, as water is lost, the turgor pressure responsible for tissue structural support weakens, ultimately causing leaves to wilt. Although it seems that in many cases leaves can be rehydrated, many leaves that fall below their wilting point never recover all the water lost. This project investigates assumptions about plant water relations with a new focus on urban tree recovery from drought. The project addresses key knowledge gaps in plant physiology, particularly focusing on an early stage experienced by plants under dry conditions. This focus allows for understanding what leads to the irreversible wilting of plant leaves and what leads to rehydration and recovery. The project also aims to improve street tree management, generate hands-on learning opportunities that effectively prepare students for the workforce, and conduct outreach events to deepen understanding of plant anatomy and physiology. By integrating dynamic biophysical properties into classical frameworks used to understand leaf wilting, the project accomplishes three objectives: (1) isolate the effect of environment on tissue-specific cellular and extra-cellular leaf water, (2) evaluate how anatomical features relate to the biological processes that occur during wilting, and (3) test predicted thresholds for irreparable damage to the leaves on trees. To meet these objectives, the work explicitly tests the assumptions of one of the most widely used tools in plant physiology, the pressure volume curve (PV-curve), leveraging histology, image analysis, laboratory and field experiments, phylogenetic mapping, and niche characterization. This project advances NSF’s priorities in Biotechnology. 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.