气候变化领域集成服务门户(CCPortal): Improved photosynthetic capacity and photosystem I oxidation via heterologous metabolism engineering in cyanobacteria

CCPortal

DOI	10.1073/pnas.2021523118
	Improved photosynthetic capacity and photosystem I oxidation via heterologous metabolism engineering in cyanobacteria
	Santos-Merino M.; Torrado A.; Davis G.A.; Rottig A.; Bibby T.S.; Kramer D.M.; Ducat D.C.
发表日期	2021
ISSN	00278424
卷号	118 期号:11
英文摘要	Cyanobacteria must prevent imbalances between absorbed light energy (source) and the metabolic capacity (sink) to utilize it to protect their photosynthetic apparatus against damage. A number of photoprotective mechanisms assist in dissipating excess absorbed energy, including respiratory terminal oxidases and flavodiiron proteins, but inherently reduce photosynthetic efficiency. Recently, it has been hypothesized that some engineered metabolic pathways may improve photosynthetic performance by correcting source/sink imbalances. In the context of this subject, we explored the interconnectivity between endogenous electron valves, and the activation of one or more heterologous metabolic sinks. We coexpressed two heterologous metabolic pathways that have been previously shown to positively impact photosynthetic activity in cyanobacteria, a sucrose production pathway (consuming ATP and reductant) and a reductant-only consuming cytochrome P450. Sucrose export was associated with improved quantum yield of phtotosystem II (PSII) and enhanced electron transport chain flux, especially at lower illumination levels, while cytochrome P450 activity led to photosynthetic enhancements primarily observed under high light. Moreover, coexpression of these two heterologous sinks showed additive impacts on photosynthesis, indicating that neither sink alone was capable of utilizing the full "overcapacity" of the electron transport chain. We find that heterologous sinks may partially compensate for the loss of photosystem I (PSI) oxidizing mechanisms even under rapid illumination changes, although this compensation is incomplete. Our results provide support for the theory that heterologous metabolism can act as a photosynthetic sink and exhibit some overlapping functionality with photoprotective mechanisms, while potentially conserving energy within useful metabolic products that might otherwise be "lost". © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Cyanobacteria; Metabolic engineering; Photoproduction; Photoprotection; Photosynthesis
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/180278
作者单位	MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, United States; Ocean and Earth Science, University of Southampton, Southampton, SO14 3ZH, United Kingdom; Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, United States
推荐引用方式 GB/T 7714	Santos-Merino M.,Torrado A.,Davis G.A.,et al. Improved photosynthetic capacity and photosystem I oxidation via heterologous metabolism engineering in cyanobacteria[J],2021,118(11).
APA	Santos-Merino M..,Torrado A..,Davis G.A..,Rottig A..,Bibby T.S..,...&Ducat D.C..(2021).Improved photosynthetic capacity and photosystem I oxidation via heterologous metabolism engineering in cyanobacteria.Proceedings of the National Academy of Sciences of the United States of America,118(11).
MLA	Santos-Merino M.,et al."Improved photosynthetic capacity and photosystem I oxidation via heterologous metabolism engineering in cyanobacteria".Proceedings of the National Academy of Sciences of the United States of America 118.11(2021).