Chemifortification of leaves through enhanced metabolic flux to tocopherol biosynthesis and plastoglobule proliferation.

ABSTRACT: Plant biofortification with phytonutrients typically relies on metabolic engineering strategies known as “push” (enhancing biosynthetic flux), “block” (inhibiting competing pathways), and “pull” (promoting metabolite storage). Here, we describe a novel chemifortification approach independent of genetic manipulation. A chemical screening identified X57, a synthetic compound that simultaneously activates all three mechanisms to enhance leaf tocopherol content. Besides their dietary value as vitamin E, tocopherols protect plants against oxidative stress and they are highly appreciated antioxidants in food and cosmetic formulations. X57 exerts a primary “push” effect by inducing tocopherol biosynthesis, in part by reactivating a direct pathway that reduces geranylgeranyl diphosphate (GGPP) to phytyl diphosphate, bypassing the need for chlorophyll-derived phytol. Accordingly, X57 promotes tocopherol accumulation in etiolated seedlings and restores tocopherol synthesis in mutants deficient in phytol phosphorylation. The “block” effect is mediated by downregulation of GGPP consumption for carotenoid synthesis. X57 also induces a “pull” effect via proliferation of plastoglobules (PG), plastidial lipoprotein bodies that synthesize and store tocopherols. X57-induced PG proliferation is driven by increased tocopherol levels and upregulation of genes for PG structural proteins such as fibrillins. X57 thus provides a powerful chemical tool for non-genetic vitamin E biofortification but also to better understand the coordination of plastidial isoprenoid metabolism and plastid differentiation.

ORGANISM(S): Arabidopsis thaliana

PROVIDER: GSE303753 | GEO | 2026/02/19

REPOSITORIES: GEO