Overexpression of <i>GhGGPPS10</i> and <i>GhGGPPS23</i> Enhances Plant Biomass Accumulation and Optimizes Photosynthetic Performance in Cotton

Terpenoids, a diverse class metabolites regulate plant growth and development. Geranylgeranyl pyrophosphate synthase (GGPPS) mediates GGPP biosynthesis through two pathways: the mevalonate (MVA) and the methylerythritol phosphate (MEP). GGPP serves as a common precursor for chlorophyll, carotenoids, and other terpenoids. We assayed the enzymatic activity of GGPPS isozymes in upland cotton and identified those with high enzymatic activity. Silencing of GhGGPPS10/23 produced leaf variegation and decreased plant height. Transcriptomic and metabolomic analyses revealed that downregulation of GhGGPPS10/23 influenced the expression patterns of genes involved in chlorophyll and carotenoid biosynthesis pathways, as well as altered metabolic fluxes. Overexpression of GhGGPPS10 and GhGGPPS23 produced significantly improved biomass and photosynthetic efficiency along with increased levels of key metabolites. Taken together, our findings indicate that GhGGPPS10/23 are involved in regulating multiple developmental processes associated with agronomically important traits.