Unraveling Environmental Effects on Excess Light Energy Dissipation in CAM-Photosynthesis of Orchids

Phalaenopsis is an economically important ornamental crop in the Netherlands, which employs Crassulacean Acid Metabolism (CAM) photosynthesis as a basic source for CO2-assimilation and growth. Phalaenopsis is an epiphyte which a natural habitat in trees and relies on water taken up by aerial roots. CAM-photosynthesis is also found in various drought-resistant species and receives increasing interest due to its potential to produce under particularly harsh environmental conditions. A hallmark of CAM-photosynthesis is stomatal closure during the day-time (to save water) and stomatal opening during the night to allow CO2-uptake which is biochemically stored (often in malate) for later use in photosynthesis during the following day.

Several student projects are available and will focus on unravelling the regulation of excess excitation energy dissipation, which occurs during the afternoon when ample light is still present and the malate- pool that provides CO2 can become depleted. Specific attention will be given to daylength and wavelength-specific responses as well as to the influence of drought-stress.
You will use combined optical (Chlorophyll Fluorescence, 820 & 540nm absorbance) and gas-exchange techniques to measure linear and cyclic electron- and proton flows that are important for (the regulation of) photosynthesis. We have a measuring system for stable C-isotope ratio measurements in our lab, which then may become part of the research.

We are searching for enthusiastic, scientifically-curious MSc and BSc-students with interest in fundamental (leaf level) physiological research on photosynthesis. Some affinity with advanced technical work and related problem solving is necessary. You will be working with a team of photosynthesis-researchers in the HPP-CSA photosynthesis lab.

Interested in doing a BSc or MSc thesis at HPP? Please contact the HPP student coordinator Katharina Hanika.