TY - JOUR TI - Photosynthesis without β-carotene AU - Xu, Pengqi AU - Chukhutsina, Volha U AU - Nawrocki, Wojciech J AU - Schansker, Gert AU - Bielczynski, Ludwik W AU - Lu, Yinghong AU - Karcher, Daniel AU - Bock, Ralph AU - Croce, Roberta A2 - Kramer, David M A2 - Hardtke, Christian S A2 - Kramer, David M A2 - Tiede, David A2 - Telfer, Alison VL - 9 PY - 2020 DA - 2020/09/25 SP - e58984 C1 - eLife 2020;9:e58984 DO - 10.7554/eLife.58984 UR - https://doi.org/10.7554/eLife.58984 AB - 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. KW - caroteonoid KW - photosynthesis KW - photosystems KW - light harvesting KW - N.tabacum JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -