Kromdijk Group: Deciphering regulation of photoprotection using PsbS sequence diversity across the green lineage.
Supervisor
Dr Johannes Kromdijk
Brief summary
Photosystem II subunit S (PsbS) is a major regulator of photoprotective energy quenching in the antenna of photosystem II, but the mechanism underlying this regulation is still not fully understood. Leveraging a major dataset of PsbS sequence diversity across the green lineage, this project aims to pinpoint the main regulatory features and their mechanistic role.
Importance of Research
Photoprotection is very important for photosynthetic organisms to survive and thrive under the specific light conditions of their specific habitats. Improved understanding of the regulation of photoprotection may provide new insights in the prerequisites for terrestrial colonization.
Project Summary
Light provides the energy for photosynthesis, but interception of excessive energy can lead to runaway ROS formation, which is dangerous for photochemical integrity and organismal health. To protect against too much light, the light harvesting antennae can switch to a dissipative state, whereby energy is released in a controlled manner. Photosystem II subunit S (PsbS) is an important regulator of this switch, but the precise mechanism is not fully understood. Since PsbS does not coordinate any pigments, it is clear that to enact its impact on energy dissipation, it must likely interact with (components of) the photosystem II light harvesting antenna. Work in the Kromdijk group recently compiled a dataset comprising PsbS sequence diversity across the green lineage. In the current project, this dataset will be leveraged to study the key functional components of PsbS, via a combination of in silico analyses and experimental work. Previous work has shown that manipulation of photoprotection can have important implications for productivity (Kromdijk et al 2016 Science) and water use efficiency (Głowacka et al 2018). The results from this project will improve understanding of the precise mechanisms involved and may provide new insights in the prerequisites for terrestrial colonization.
What will the successful applicant do?
The successful applicant will analyse sequence diversity in Photosystem II subunit S (PsbS) across the green lineage, using a novel dataset compiled in the Kromdijk lab, to identify features with potential importance for PsbS functioning and/or interactions with PSII antenna proteins. Hypotheses from in silico analyses will be followed up with mutant complementation studies
References
Glowacka K, Kromdijk J, Katherine Kucera, Jiayang Xie, Cavanagh AP, Leonelli L, Leakey ADB, Ort DR, Niyogi KK, Long SP 2018. Photosystem II Subunit S overexpression increases the efficiency of water use in a field-grown crop. Nature communications 9 (1): 868. doi.org/10.1038/s41467-018-03231-x
Kromdijk J, Glowacka K, Leonelli L, Gabilly S, Iwai M, Niyogi KK, Long SP. 2016. Improving photosynthesis and crop productivity by accelerating recovery from photoprotection. Science 354 (6314): 657-861. DOI:10.1126/science.aai8878