New study sheds light on evolution of photosynthesis

Rutgers University researchers shed new light on photosynthesis evolution in plants and algae. This could lead to improved crop production.The paper is published in the journal New Phytologist.Researchers reviewed research on Paulinella, a photosynthetic amoeba that is used as a model to investigate a fundamental question regarding eukaryote evolutionary history: Why was there only one origin for algae and plants. This is why photosynthesis by primary endosymbiosis did not occur multiple times in the tree.Photosynthesis refers to the process whereby plants and other organisms use sunlight for photosynthesis, which produces oxygen as a byproduct.Endosymbiosis refers to a relationship in which one organism lives within the other. If the interaction is stable and healthy for the "host", it can lead to massive genetic innovation. Although endosymbiosis plays a critical evolutionary role in evolution, we have limited information about how it is first established.Primary plastid endosymbiosis is a process by which an eukaryote (organs like plants and algae with a membrane bound nucleus and small organs called organelles) engulfs and swallows a prokaryote (organs like bacteria without a membrane-enclosed nuclear nucleus). It was developed about 1.5 billion years ago. The plastid, a membrane-bound organelle in the cells of plants or algae, is called."It turns out, photosynthesis poses enormous risks because it produces harmful chemicals and high temperatures as byproducts which can damage the host cells," said Debashish Bhattacharya (a senior author) and Distinguished Professor at Rutgers University New Brunswick. "Creating a novel organelle is therefore a complex process, making it rare in evolution. Paulinella is the only case of a plastid primary endosymbiosis that is independent from plants and algae. It offers many clues about this process which helps to explain why it is so rare.Photosynthesis, the process of photosynthesis occurring in plants and algae, has had a profound impact on our planet. It provided a major source for oxygen and supported many ecosystems. This critical process can be reengineered in synthetic systems and improved crop production by understanding how it happened.Timothy G. Stephens (a Rutgers postdoctoral researcher), led the research. He said that Paulinella, an independent source of photosynthesis, provides key clues as to how it occurs and what costs it incurs. Paulinella's genome contains many genes that are independently developed and involved in photosynthesis. This could be used to engineer plants to better withstand stress such as salt and high light.Researchers from Carnegie Institution participated in the study.Video: https://www.youtube.com/watch/Pbosfj1oV6IVideo: https://www.youtube.com/watch/v=nJ9ApL9Mq6w&t=3s