Elucidating the role of a novel DNA-binding protein identified in the diatom Thalassiosira pseudonana for coping with nutrient and temperature stress

Sarkozi, Krisztina (2016) Elucidating the role of a novel DNA-binding protein identified in the diatom Thalassiosira pseudonana for coping with nutrient and temperature stress. Doctoral thesis, University of East Anglia.

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Abstract

Diatoms are associated with nutrient rich waters with high biomass that are commonly found at high latitudes, in coastal waters, in upwelling zones or during seasonal blooms.They display an opportunistic growth described as a ’bloom and bust’ life cyce and a
remarkable diversity. These caracteristics are considered to be responsible for their success in aquatic environments and the reason why they contribute about 20% of global primary production and allow them to quickly dominate phytoplankton communities when environmental conditions become favourable. The processes that
enable this impressive plasticity of diatoms in response to environmental variability are mostly unknown. A novel conserved DNA binding protein (BIG1) was recently identified and found to differentially regulate genes involved in progression through the cell cycle in centric diatoms as well as about 30% of genes found in natural centric diatom blooms. In our study we show that the BIG1 protein is linked to the regulation of initiation of fast growth upon nutrient addition. Overexpression of BIG1 in the model centric diatom Thalassiosira pseudonana enabled fast recovery and growth after a
period of nitrogen stravation and exposure to low and high temperature as well as fostered growth under suboptimal temperatures. We present evidence that BIG1 has an impact on photosynthesis and suggest its involvement in directing the photosynthetic electron flow around Photosystem I. Our results may provide insights into regulatory processes that govern diatoms’ oportunistic growth.

Item Type: Thesis (Doctoral)
Faculty \ School: Faculty of Science > School of Environmental Sciences
Depositing User: Brian Watkins
Date Deposited: 29 Nov 2017 16:18
Last Modified: 29 Nov 2017 16:18
URI: https://ueaeprints.uea.ac.uk/id/eprint/65626
DOI:

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