Prof. Thomas Mock works in the fields of evolution, cell biology, reverse genetics and genomics with marine algae and their microbiomes (e.g., prokaryotes, viruses) from the global upper ocean to understand their ecology, (co-)evolution and adaptation. This work leads to the identification of biological mechanisms that shape the evolution of algal microbiomes and are therefore responsible for their adaptation to different environmental conditions including climate change. He pioneered contributions that advanced the field of algal research through method development (e.g., CRISPR/Cas-based genome engineering, ribosome profiling) and multi-omics approaches. Prof. Mock published highly cited articles in Nature, Nature Methods, Science, Cell, PNAS, and Nature Communications. He is co-editor in chief of the ‘Journal of Phycology’. He was elected to the Royal Society of Biology and the Higher Education Academy in the UK. In 2019, he was appointed Guest Professor of the Ocean University of China, and in 2022, he has received the Qilu Friendship award. In 2023, he became honorary citizen of the Shandong Province.

报告摘要：

Microbial rhodopsins are photoreceptor proteins that convert light into biological signals or energy. Proteins of the xanthorhodopsin family are common in eukaryotic photosynthetic plankton including diatoms. However, their biological role in these organisms remains elusive. This talk will give an overview of how xanthorhodopsin proteins can support the growth of diatoms in the ocean. Although all known variants of microbial rhodopsins in diatoms are pump protons, their biological role appears to depend on the subcellular localisation. A striking example is the xanthorhodopsin variant FcR1 isolated from the polar diatom Fragilariopsis cylindrus. FcR1 is a plastid-localized proton pump which binds the chromophore retinal and is activated by green light. Enhanced growth of a Thalassiora pseudonana gain-of-function mutant expressing FcR1 under iron limitation shows that the xanthorhodopsin proton pump supports growth when chlorophyll-based photosynthesis is iron-limited. The abundance of xanthorhodopsin transcripts in natural diatom communities of the surface oceans is anticorrelated with the availability of dissolved iron. Thus, these results suggest that FcR1 and homologs in other diatom species that are also targeted to the plastid convey a fitness advantage in regions where phytoplankton growth is limited by the availability of dissolved iron.