Mechanistic Modeling of Sucrose Transport in Plant Phloem

Project Details

• Student(s): Nour Doughan
• Advisor(s): Dr. Mazen Nakad
• Department: Chemical
• Academic Year(s): 2025-2026

Abstract

Sucrose transport through the phloem governs the redistribution of carbon fixed in leaves to non-photosynthetic tissues such as stems and roots. In many vegetation models, this transfer is treated as instantaneous, and the physical constraints associated with transport along the phloem pathway are neglected. Here, a modeling framework is developed in which sucrose concentration dynamics are coupled with pressure-driven flow in the phloem. Sink activity is represented as a first-order reaction, such that sugar removal depends on local sucrose concentration. Results show that sink strength influences concentration profiles, pressure gradients, and the delivery of sugar to different plant organs. Accounting for transport limitations alters predicted carbon allocation among leaves, stems, and roots relative to simplified allocation approaches. This work provides a step toward a more mechanistic treatment of carbon allocation in vegetation and land-surface models.