Plant Photobiology

The produced carbohydrates by photosynthesis serve as key molecules for plant development and growth. Significant amounts of the carbohydrates produced in the source tissue are transported throughout the plant in the form of sucrose. That makes sucrose one of the crucial carbohydrates in terms of distribution of energy source and as a pre-cursor for many biological molecules in plants. Source to sink sucrose transportation determines the carbon allocation for growth and development across all plant organs through a specialized tissue, the phloem. From photosynthetic cells in source tissues, sucrose is exported to the apoplastic space via SWEET (SUGARS WILL EVENTUALLY BE EXPORTED) transporters. Then, it is actively loaded into the phloem by the sucrose/H+ symporter SUC2. After sucrose is transported from source to sink (e.g. hypocotyl), phloem unloading occurs. Although some sucrose unloading mechanisms and their regulation for terminal sink organs such as the root have been identified, it is unknown how it takes place in so-called axial sinks such as hypocotyls, or how this is regulated. The allocation of sucrose through these paths is regulated by many stimuli. As an example, many plants that are exposed to vegetation shade from nearby plants (neighbor detection) grow longer hypocotyls to compete for light. The reflection of light from plant tissue leads to spectral changes which are sensed by phytochrome photoreceptors. Importantly, in this response, plants adjust their sucrose allocation to allow longer hypocotyls. Nonetheless, how shade signaling regulates carbon allocation remains poorly understood. Therefore, we aim to shed light on sucrose allocation, focusing on sucrose unloading in the hypocotyl and how this is regulated by shade signaling. The route of sucrose transport in neighbor detection, role of sucrose-metabolism enzymes (invertases and sucrose synthases) and sucrose transporters for sucrose allocation will be evaluated. The potential findings may be relevant for the improvement of crops which are axial sinks (e.g. stem vegetables).

Presentations

Poster Presentation: ICT2022. Maastrich, Netherlands. 2022 Certificate

Poster Presentation: YRSPP2024. Utrecht, Netherlands. Best Poster Award 2024 Certificate

Publications

Onder, A. C.; Reyes-Hernández, B. J.; Krahmer, J. Mechanisms of Carbon Allocation to Stem-like Axial Sink Organs. J Exp Bot 2026, 77 (5), 1469–1482. DOI

Cappetta, E.; Del Regno, C.; Conte, M.; Castro-Hinojosa, C.; Del Sol-Fernández, S.; Vergata, C.; Buti, M.; Curcio, R.; Onder, A.; Mazzei, P.; Funicello, N.; De Pasquale, S.; Terzaghi, M.; Del Gaudio, P.; Leone, A.; Martinelli, F.; Moros, M.; Ambrosone, A. An Integrated Multilevel Approach Unveils Complex Seed–Nanoparticle Interactions and Their Implications for Seed Priming. ACS Nano 2023, 17 (22), 22539–22552. DOI

Onder, A. C.; Tomak, A.; Oksel Karakus, C. Optimizing the Dispersion of Calcium Phosphate Nanoparticles for Cellular Studies Using Statistical Design of Experiments. Ceramics International 2023, 49 (16), 26890–26899. DOI