Photosynthesis without β-carotene

Pengqi Xu, Volha U. Chukhutsina, Wojciech J. Nawrocki, Gert Schansker, Ludwik W. Bielczynski, Yinghong Lu, Daniel Karcher, Ralph Bock, Roberta Croce*

*Corresponding author for this work

Research output: Contribution to JournalArticleAcademicpeer-review

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.

Original languageEnglish
Article numbere58984
Pages (from-to)1-16
Number of pages16
JournaleLife
Volume9
DOIs
Publication statusPublished - 25 Sept 2020

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