Abstract Detail


Rahmatpour, Nasim [1], Hauser, Duncan [1], Nelson, Jessica [2], Villarreal Aguilar, Juan Carlos [3], Ho, Ming-Yang [4], Li, Fay-Wei [5].

A new extant cyanobacterial lineage that diverged from Gloeobacterover 1.4 billion years .

Cyanobacteria propelled the rise of oxygen photosynthesis 2.3 billion years ago and marked an epic transformation of life on earth. The genus Gloeobacter, as an earliest diverging group of living cyanobacteria and recently Aurora, a sister group to Gloeobacter, have brought attention to investigate the early evolution of photosynthetic organisms. Here we described a novel cyanobacterium that is sister to Gloeobacter, but diverged from it over 1.4 billion years ago based on molecular dating. Our ultrastructural, physiological, and genomic analyses revealed that this species possess a unique combination of traits that are either exclusively shared with Gloeobacteror with other crown Cyanobacteria. For example, it lacks thylakoids like in Gloeobacter, but its carotenoid biosynthesis pathway is much more similar to that in the crown Cyanobacteria. Furthermore, although this species contains most genes necessary for oxygenic photosynthesis from Photosystem I (PSI) and Photosystem II (PSII), certain subunits of PSI, PSII, cytochrome b6/f, electron transport chain, as well as all phycoerythrin subunits are missing. Such unique assembly of photosynthetic apparatus might be related to its low tolerance to high light intensity. Given its key phylogenetic position and distinct trait combination, we anticipate this culture will open a new window to further illuminate the dawn of photosynthesis.  

1 - Boyce Thompson Institute, 533 Tower Road , Ithaca, NY, 14853
2 - Maastricht University, Netherland
3 - Laval University, Canada
4 - National Taiwan University, Taiwan
5 - Cornell University, Ithaca, NY


Presentation Type: Oral Paper
Session: PHYL2, Phylogenomics II
Location: Virtual/Virtual
Date: Wednesday, July 29th, 2020
Time: 1:45 PM
Number: PHYL2006
Abstract ID:551
Candidate for Awards:None

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