Thesis topic proposal
Imre Vass
The role and significance of cyclic electron transport in microalgae


Institute: University of Szeged
Doctoral School of Biology

Thesis supervisor: Milán Szabó
co-supervisor: Imre Vass
Location of studies (in Hungarian): Biological Research Centre, Institute of Plant Biology
Abbreviation of location of studies: SzBK

Description of the research topic:

Photosynthesis is a series of redox reactions, in which several electron transport processes operate to provide the energetic balance of light harvesting. Besides linear electron flow, which ensures the basic functions of photosynthetic productivity and carbon fixation, alternative electron transport pathways operate, i.e. the cyclic electron transport, which play a role in fine-tuning of photosynthesis and balancing the ATP/NADPH ratio under stress conditions. The enzymes NAD(P)H dehydrogenases (NDHs) play important role in the regulation of cyclic electron transport by mediating the electron flow from stromal NAD(P)H to the plastoquinone molecules located in the lipid phase of the thylakoid membranes. The type I NDH is well characterized in several microalgae species, however some species possess only type II NDH dehydrogenase (NDH-2), the role of which in cyclic electron flow remains uncharacterized so far.
The aim of the project is the characterization of NDH-2 mediated cyclic electron flow in microalgae that play crucial role in aquatic ecosystems (the coral endosymbiont Symbiodinium sp.), and in species that have high relevance in bioenergy (e.g. biofuel) and valuable compounds (e.g. carotenoid) production (Chlorella sorokiniana, Haematococcus pluvialis, Nannochloropsis sp.). Various biophysical methods (variable chlorophyll fluorescence, NADPH fluorescence, absorption kinetics) will be applied to investigate the impact of various stress conditions on the rate of cyclic electron flow. The components of cyclic electron transport chain will be assayed using inhibitors and mutants. Thus we aim to understand the species-specific characteristics and the role of cyclic electron flow in mediating stress responses.

Required language skills: English
Further requirements: 
dedication to scientific work

Number of students who can be accepted: 2

Deadline for application: 2020-12-31

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