Poster Presentation International Plant Molecular Biology Conference 2024

Modular pathway engineering for terpenoid biosynthesis in rice plants (#208)

Sun-Hwa Ha 1
  1. Kyung Hee University, Yongin, GYEONGGI-DO, South Korea

Terpenoid, the largest group of metabolites, has primary functions being involved in photosynthesis (carotenoids and chlorophylls), growth and development (CK, GAs, ABA, and SLs), and respiration (ubiquinone) and also specialized roles responding to environment in plants. Some are economically important as flavors, pigments, polymers, pharmaceuticals, and pesticides but their production is usually low in planta. To meet needs as high valued molecules, plant metabolic engineering based on synthetic biology has been presented as one of solutions. Terpene compounds are initially composed of two isoprene building blocks, IPP and DMAPP, which are originated via either a plastidial methylerythritol 4-phosphate pathway (module 1) or a cytosolic mevalonate pathway, sequentially condensed into the terpene precursors of GPP for monoterpenes, FPP for a sesquiterpenes and triterpenes, and GGPP for diterpenes and tetraterpenes by several types of prenyl transferases (PTs, module 2), and converted into various terpenoids by diverse actions of terpene synthases (TPSs, module 3) mediating condensation, cyclization, reduction, glycosylation etc.. Some undergo catabolic processes into cleavage products (module 4). In fact, terpene metabolism has species-specific manners. To establish platform for terpene production in rice, we modularized the terpene path into four parts and conducted the functional studies of OsDXS, OsDXR, and OsIspH for module 1, OsPTs for module 2, and OsCCDs for module 4 on the basis of carotenoid-accumulating color systems (module 3) such as E. coli and rice seeds. Currently, we are elucidating the best combination among modules for the production of specialized terpenes in rice callus color system.