Arabidopsis GERANYLGERANYL DIPHOSPHATE SYNTHASE 11 is a hub isozyme required for the production of most photosynthesis‐related isoprenoids

Summary Most plastid isoprenoids, including photosynthesis‐related metabolites such as carotenoids and the side chain of chlorophylls, tocopherols (vitamin E), phylloquinones (vitamin K), and plastoquinones, derive from geranylgeranyl diphosphate ( GGPP ) synthesized by GGPP synthase ( GGPPS ) enzymes. Seven out of 10 functional GGPPS isozymes in Arabidopsis thaliana reside in plastids. We aimed to address the function of different GGPPS paralogues for plastid isoprenoid biosynthesis. We constructed a gene co‐expression network ( GCN ) using GGPPS paralogues as guide genes and genes from the upstream and downstream pathways as query genes. Furthermore, knock‐out and/or knock‐down ggpps mutants were generated and their growth and metabolic phenotypes were analyzed. Also, interacting protein partners of GGPPS 11 were searched for. Our data showed that GGPPS 11 , encoding the only plastid isozyme essential for plant development, functions as a hub gene among GGPPS paralogues and is required for the production of all major groups of plastid isoprenoids. Furthermore, we showed that the GGPPS 11 protein physically interacts with enzymes that use GGPP for the production of carotenoids, chlorophylls, tocopherols, phylloquinone, and plastoquinone. GGPPS 11 is a hub isozyme required for the production of most photosynthesis‐related isoprenoids. Both gene co‐expression and protein–protein interaction likely contribute to the channeling of GGPP by GGPPS 11.