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Functional integration of non‐native carotenoids into chloroplasts by viral‐derived expression of capsanthin–capsorubin synthase in Nicotiana benthamiana
Author(s) -
Kumagai Monto H.,
Keller Yves,
Bouvier Florence,
Clary David,
Camara Bilal
Publication year - 1998
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1046/j.1365-313x.1998.00128.x
Subject(s) - nicotiana benthamiana , xanthophyll , carotenoid , chromoplast , biology , thylakoid , chloroplast , biochemistry , photosystem ii , atp synthase , chlorophyll , microbiology and biotechnology , botany , photosynthesis , plastid , enzyme , gene
Summary The biosynthesis of leaf carotenoids inNicotiana benthamiana was altered by forced re‐routing of the pathway to the synthesis of capsanthin, a non‐native chromoplast‐specific xanthophyll, using an RNA viral vector containing capsanthin–capsorubin synthase (Ccs ) cDNA. The cDNA encodingCcs was placed under the transcriptional control of a tobamovirus subgenomic promoter. Leaves from transfected plants expressingCcs developed an orange phenotype and accumulated high levels of capsanthin (up to 36% of total carotenoids). This phenomenon was associated with thylakoid membrane distortion and reduction of grana stacking. In contrast to the situation prevailing in chromoplasts, capsanthin was not esterified and its increased level was balanced by a concomitant decrease of the major leaf xanthophylls, suggesting an autoregulatory control of chloroplast carotenoid composition. Capsanthin was exclusively recruited into the trimeric and monomeric light‐harvesting complexes of photosystem II (PSII) and shown to significantly contribute to the light‐harvesting capacity. On a chlorophyll basis, the concentrations of PSI and PSII reaction centres were not modified. This demonstration that higher plant antenna complexes can accommodate non‐native carotenoids provides compelling evidence for functional remodelling of photosynthetic membranes toward a better photoreactivity by rational design of the incorporated carotenoid structures.