Photosynthesis without β-carotene
- Vrije Universiteit Amsterdam, Netherlands
- Max Planck Insitute of Molecular Plant Physiology, Germany
Abstract
Carotenoids are essential in oxygenic photosynthesis: they stabilize the pigment-protein complexes, are active in harvesting sunlight and in photoprotection. In plants, they are present as carotenes and their oxygenated derivatives, xanthophylls. While mutant plants lacking xanthophylls are capable of photoautotrophic growth, no plants without carotenes in their photosystems have been reported so far, which has led to the common opinion that carotenes are essential for photosynthesis. Here, we report the first plant that grows photoautotrophically in the absence of carotenes: a tobacco plant containing only the xanthophyll astaxanthin. Surprisingly, both photosystems are fully functional despite their carotenoid-binding sites being occupied by astaxanthin instead of β-carotene or remaining empty (i.e., are not occupied by carotenoids). These plants display non-photochemical quenching, despite the absence of both zeaxanthin and lutein and show that tobacco can regulate the ratio between the two photosystems in a very large dynamic range to optimize electron transport.
Data availability
All data used for this study are included in the manuscript or in the supporting information. The source data used to generate figure S7 are provided.
Article and author information
Author details
Wojciech J Nawrocki
Funding
Nederlandse Organisatie voor Wetenschappelijk Onderzoek (Vici)
- Roberta Croce
H2020 European Research Council (ERC CON 281341)
- Roberta Croce
H2020 European Research Council (ERC ADG 669982)
- Ralph Bock
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2020, Xu et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Photosynthesis without β-carotene
eLife 9:e58984.
https://doi.org/10.7554/eLife.58984
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