Expanding the View: Thylakoid (Re)organisation and Spectral Tuning in Photosynthesis

Summary

Plants grow in very different light environments, from full sunlight in the open field to deep shade under forest canopies. Moreover, in many niches, the light intensity can fluctuate as well. This thesis explores how plants respond to short term (minutes) and long term (evolutionary) alterations in light intensity and spectrum. Firstly, I used a special camera to separate fluorescence on time and wavelength to study how the energy is divided in the photosynthetic membrane. Secondly, I used this and other techniques to study the difference of the photosynthetic machinery between shade and sun-adapted plants. Thirdly, I applied expansion microscopy (ExM) to the photosynthetic membrane. Chloroplasts were embedded in a swellable gel and subsequently 4-5x expanded to increase the distance between proteins and therefore the effective resolution of imaging. With this, I observed the membranes reorganise in response to changing light. These changes happened within just 10 minutes, showing how quickly plants can respond.