An Engineered Extraplastidial Pathway for Carotenoid Biofortification Of
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An engineered extraplastidial pathway for carotenoid biofortification of leaves Trine Andersen, Briardo Llorente, Luca Morelli, Salvador Torres-montilla, Guillermo Bordanaba-florit, Fausto Espinosa, Maria Rosa Rodriguez-goberna, Narciso Campos, Begoña Olmedilla-alonso, Manuel Llansola-Portoles, et al. To cite this version: Trine Andersen, Briardo Llorente, Luca Morelli, Salvador Torres-montilla, Guillermo Bordanaba- florit, et al.. An engineered extraplastidial pathway for carotenoid biofortification of leaves. Plant Biotechnology Journal, Wiley, 2021, 19 (5), pp.1008-1021. 10.1111/pbi.13526. hal-03286028 HAL Id: hal-03286028 https://hal.archives-ouvertes.fr/hal-03286028 Submitted on 16 Jul 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Plant Biotechnology Journal (2021) 19, pp. 1008–1021 doi: 10.1111/pbi.13526 An engineered extraplastidial pathway for carotenoid biofortification of leaves Trine B. Andersen1,† , Briardo Llorente1,2,3 , Luca Morelli1 , Salvador Torres-Montilla1 , Guillermo Bordanaba-Florit1, Fausto A. Espinosa1, Maria Rosa Rodriguez-Goberna1, Narciso Campos1,4 , Begona~ Olmedilla-Alonso5 , Manuel J. Llansola-Portoles6 , Andrew A. Pascal6 and Manuel Rodriguez-Concepcion1,7,* 1Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Barcelona, Spain 2Department of Molecular Sciences, ARC Center of Excellence in Synthetic Biology, Macquarie University, Sydney, NSW, Australia 3CSIRO Synthetic Biology Future Science Platform, Sydney, NSW, Australia 4Departament de Bioquı´mica i Biologia Molecular,Universitat de Barcelona, Barcelona, Spain, 08028 5Instituto de Ciencia y Tecnologıa de Alimentos y Nutricion (ICTAN-CSIC), Madrid, Spain 6CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Universite Paris-Saclay, Gif-sur-Yvette, France 7Instituto de Biologia Molecular y Celular de Plantas (IBMCP), CSIC-Universitat Politecnica de Valencia, Valencia, Spain Received 2 April 2020; Summary accepted 9 December 2020. Carotenoids are lipophilic plastidial isoprenoids highly valued as nutrients and natural pigments. *Correspondence (Tel (+34) 963 877 725; A correct balance of chlorophylls and carotenoids is required for photosynthesis and therefore + fax ( 34) 963 877 859; email highly regulated, making carotenoid enrichment of green tissues challenging. Here we show that [email protected]) leaf carotenoid levels can be boosted through engineering their biosynthesis outside the †Present address: Great Lakes Bioenergy chloroplast. Transient expression experiments in Nicotiana benthamiana leaves indicated that Research Center, Michigan State University, East Lansing, MI, 48824, USA high extraplastidial production of carotenoids requires an enhanced supply of their isoprenoid precursors in the cytosol, which was achieved using a deregulated form of the main rate- determining enzyme of the mevalonic acid (MVA) pathway. Constructs encoding bacterial enzymes were used to convert these MVA-derived precursors into carotenoid biosynthetic intermediates that do not normally accumulate in leaves, such as phytoene and lycopene. Cytosolic versions of these enzymes produced extraplastidial carotenoids at levels similar to those of total endogenous (i.e. chloroplast) carotenoids. Strategies to enhance the development of endomembrane structures and lipid bodies as potential extraplastidial carotenoid storage systems were not successful to further increase carotenoid contents. Phytoene was found to be more bioaccessible when accumulated outside plastids, whereas lycopene formed cytosolic Keywords: carotenoids, phytoene, crystalloids very similar to those found in the chromoplasts of ripe tomatoes. This extraplastidial lycopene, biosynthesis, Nicotiana production of phytoene and lycopene led to an increased antioxidant capacity of leaves. Finally, benthamiana, lettuce, bioaccessibility, we demonstrate that our system can be adapted for the biofortification of leafy vegetables such antioxidant, biofortification. as lettuce. Introduction biosynthetic pathway) are colourless (Rodriguez-Concepcion et al., 2018). Carotenoids are lipophilic isoprenoids distributed throughout all In plants, carotenoids are synthesized in plastids from the kingdoms of life. Plants and some bacteria, archaea and fungi universal C5 isoprenoid precursors isopentenyl diphosphate (IPP) can biosynthesize these compounds de novo, whereas the vast and dimethylallyl diphosphate (DMAPP) produced by the majority of animals acquire them through their diet (Rodriguez- methylerythritol 4-phosphate (MEP) pathway (Figure 1). Other Concepcion et al., 2018; Zheng et al., 2020). Carotenoids are plastidial isoprenoids, such as monoterpenoids and the prenyl an essential part of the human diet, acting as precursors of moieties of chlorophylls and tocopherols, are produced using the retinoids (including vitamin A) and health-promoting molecules. same pool of substrates. In the cytosol, a second pool of IPP and They are also economically relevant as natural pigments that DMAPP is synthesized by the mevalonic acid (MVA) pathway for provide colours in the yellow to red range to many fruits, the production of sesquiterpenoids and triterpenoids (including vegetables, seafood, fish, poultry and dairy products. One sterols). Plastid-localized isoforms of geranylgeranyl diphosphate example is lycopene, which gives rise to the red colour in ripe (GGPP) synthases catalyse the condensation of three IPP and one tomatoes. Carotenoids with a shorter conjugation length such DMAPP into one C20 GGPP. Two GGPP molecules are then as phytoene (the first committed intermediate of the converted into one C40 phytoene by phytoene synthase. 1008 ª 2020 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. Extraplastidial carotenoid synthesis 1009 Desaturation and isomerization of phytoene produce lycopene, a (crtI) resulted in the production of lycopene in the cytosol of linear carotenoid whose ends may then be cyclized into b and/or e tobacco (Nicotiana tabacum) cells (Majer et al., 2017). Virus- rings. The formation of two b rings results in the production of b- infected tissues accumulated lycopene to levels up to 10% of the carotene, from which b-b xanthophylls such as violaxanthin and total leaf carotenoid content, but only for 1–2 days, as neoxanthin are formed through oxidation. The formation of one carotenoid-producing leaves soon became necrotized. Such b and one e ring leads to the production of lutein, the most deleterious phenotype may be caused by side-effects of the viral abundant xanthophyll in photosynthetic tissues (Figure 1a). In infection, by the diversion of metabolic substrates away from chloroplasts, carotenoids are involved in light harvesting and cytosolic isoprenoid pathways, and/or by negative interference of photoprotection against excess light, and their levels are finely the lipophilic lycopene with cell membrane function. Here we balanced with those of chlorophylls for the efficient assembly and tested new strategies to circumvent these problems using functionality of photosynthetic complexes (Domonkos et al., phytoene and lycopene as the target products. The choice of 2013; Esteban et al., 2015; Hashimoto et al., 2016). Carotenoids these carotenoid intermediates (Figure 1a) was based on three can also be produced and stored at high levels in chromoplasts, main reasons. First, they are virtually absent in non-engineered which are specialized plastids found in some non-photosynthetic leaves as they are readily converted into downstream chloroplast tissues of flowers, fruits and other carotenoid-accumulating carotenoids (Domonkos et al., 2013; Esteban et al., 2015; tissues (Sadali et al., 2019; Sun et al., 2018). Hashimoto et al., 2016; Rodriguez-Concepcion et al., 2018). Several biotechnological strategies have been tested to enrich Second, their supply is essential for the eventual production of plant-derived feed and food products with carotenoids to any downstream carotenoid of interest. And third, they are improve their nutritional and economic value (Alos et al., 2016; health-promoting phytonutrients that are only found in a few Zheng et al., 2020). While highly successful results have been food sources (Melendez-Martinez et al., 2015; Melendez- obtained in non-photosynthetic tissues, including Golden Rice, Martinez et al., 2018; Muller€ et al., 2011; Rodriguez-Concepcion manipulation of carotenoid levels in photosynthetic tissues has et al., 2018). been much more challenging. We have investigated methods to produce carotenoids in green tissues without interfering with Results photosynthetic function by moving their biosynthesis away from Agroinfiltrated leaves can produce extraplastidial