| Title | Single-nucleus transcriptomics reveals laticifer-specific transcriptional programs and triterpenoid-rubber metabolic coordination in Euphorbia lathyris L |
| Author | Liu, Fang |
| Publication | INDUSTRIAL CROPS AND PRODUCTS |
| Year | 2026 |
| Volume | 243 |
| Corresponding Author | Pan, JJ; Sun, GL |
| Abstract | Laticifers are specialized secretory cells that synthesize and store latex and provide a model for studying cellular specialization in plant metabolism. Euphorbia lathyris L. possesses non-articulated laticifers that produce triterpenoid-rich latex, but the mechanistic basis of laticifer specialization and latex metabolism remains unclear. Here, we generate the single-nucleus transcriptomic landscape of E. lathyris leaves and resolve a continuous laticifer trajectory with progressive activation of the mevalonate-derived triterpenoid pathway. Genes encoding the rubber biosynthetic complex, including cis-prenyltransferase (CPT), CPT-binding protein (CBP), and small rubber particle protein (SRPP), were specifically expressed in laticifers, indicating potential rubber formation. Ultrastructural and chemical analyses detect small rubber particles (similar to 150 nm) and a low-abundance cis-1,4-polyisoprene fraction in latex (0.30-0.47% w/w) with short average chain length (Mw approximate to 150-180 kDa). The streamlined repertoire of rubber biosynthetic pathway genes and the absence of Hevea-like rubber elongation factors (REFs) may be associated with the observed low rubber content and smaller molecular weight in E. lathyris. Network inference and validation identified a laticifer-specific DOF transcription factor, COGWHEEL1 (ElCOG1), that binds the promoters of ElCPT1 and butyrospermol synthase 1 (ElBUT1) and represses their activity, indicating a shared negative transcriptional control point acting on both the rubber-elongation and triterpenoid branches. In summary, this single-nucleus transcriptomic landscape of E. lathyris laticifers clarifies their metabolic specialization and establishes a framework for dissecting the regulatory programs of specialized secretory cells in latex-bearing plants. |
