2026/07/01 by Xue Hou, Songle Fan, Yushuang Yang +4
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Chromosomal and Genetic Variations #Plant Reproductive Biology #Plant biochemistry and biosynthesis
paper · doi:10.1016/j.plaphy.2026.111593
openalex publication_date 2026/07/01 · openalex created_date 2026/07/29 · openalex updated_date 2026/08/01
Natural rubber (NR) is predominantly obtained from Hevea brasiliensis, where cis-prenyltransferase (CPT) catalyzes NR biosynthesis. However, the evolutionary trajectories, functional validation, and applicability of rubber tree CPTs for enhancing NR production in non-Hevea species remain unclear. Here, comparative evolutionary analysis across Euphorbiaceae family revealed that H. brasiliensis underwent a tandem duplication-driven expansion of its CPT family-especially among core members HbCPT6, HbCPT7, and HbCPT8-forming a gene cluster. Notably, HbCPT8 exhibits latex-specific expression and is significantly upregulated in secondary laticifers, linking it to NR production. In Taraxacum kok-saghyz (TKS), overexpression of HbCPT8 significantly increased rubber particles (RPs) abundance and plant biomass. Most importantly, overexpressing HbCPT8 markedly enhanced NR yield in TKS, while concurrently reducing inulin content and increasing free sugar levels. Moreover, HbCPT8 overexpression promotes the accumulation of lipids and terpenoids. Transcriptomic analysis revealed upregulation of genes involved in secondary metabolism, sesquiterpene/triterpene biosynthesis, fatty acid degradation, and carbon metabolism. Notably, key genes in mevalonate pathway and rubber elongation-including CPT/CPTL and RP-associated genes-were markedly upregulated. These findings demonstrate that HbCPT8 overexpression in TKS enhances RP biogenesis and NR biosynthesis, coordinately upregulates genes encoding core components of the rubber elongation complex and key enzymes in precursor biosynthesis, and redirects carbon flux toward isoprenoid biosynthesis, thereby increasing NR yield and terpenoid accumulation. This study confirm the evolutionarily conserved role of CPT in NR biosynthesis across rubber-producing species, establish HbCPT8 as a validated target for boosting NR production, and provide a mechanistic basis for engineering high-yielding rubber crops.