Natural Rubber Biosynthesis in Plant Systems

Natural rubber is a high-molecular-weight polymer of cis-1,4-polyisoprene that is synthesised and stored in specialised laticifer cells of certain plants, most notably Hevea brasiliensis. Biosynthesis relies on the coordinated action of isoprenoid precursor pathways, chiefly the mevalonate pathway, to supply isopentenyl diphosphate units, which are then polymerised by a cis-prenyltransferase-containing complex on the surface of rubber particles. Key protein components include rubber elongation factor and small rubber particle protein, which stabilise the growing polymer and define particle architecture. Ethylene acts as a stimulatory signal, modulating gene expression and enzymatic activity in laticifers to boost yield. Recent advances in genome sequencing, transcriptomics and proteomics have elucidated domestication traits, gene family expansions and the regulatory networks governing laticifer differentiation. Parallel work in alternative rubber-producing species such as Taraxacum kok-saghyz has revealed convergent molecular mechanisms and offers routes to diversify rubber supply under changing climatic conditions.

Research from Nature Portfolio

High-resolution genome assemblies of Hevea brasiliensis have uncovered the genetic basis of domestication traits, including a small-peptide hormone gene that drives the proliferation of laticifer rings and enhances rubber yield. Comparative resequencing of hundreds of accessions has pinpointed selection signals in genes linked to latex biosynthesis and cell differentiation, and heterologous expression studies have validated the capacity of these loci to increase rubber content in alternative hosts. A foundational chromosome-level assembly has also revealed an extensive expansion of the REF/SRPP gene family and the emergence of a dominant REF isoform, shedding light on the evolution of the protein machinery that underpins high-molecular-weight polymer assembly and clarifying the role of ethylene signalling in laticifer-specific regulation of biosynthetic enzymes.

Natural Rubber Biosynthesis in Plant Systems publication trend

The graph below shows the total number of articles in natural rubber biosynthesis in plant systems across all publications each year (not limited to Nature Index journals).

Technical terms

laticifer: A specialised tubular cell or series of cells in certain plants that produces and contains latex.

rubber particle: A subcellular organelle in laticifers comprising a lipid monolayer enclosing polymerising polyisoprene chains.

cis-prenyltransferase: An enzyme that catalyses the sequential addition of isopentenyl diphosphate units in cis-configuration during natural rubber polymerisation.

rubber elongation factor (REF): A protein that associates with rubber particles and enhances the elongation of polyisoprene chains.

small rubber particle protein (SRPP): A structural protein that stabilises small rubber particles and contributes to efficient biosynthesis.

mevalonate (MVA) pathway: A metabolic route in the cytosol that generates isopentenyl diphosphate, the universal precursor for isoprenoid and rubber biosynthesis.

References

1. Genomic insight into domestication of rubber tree. Nature Communications (2023).
2. Chromosome‐level wild Hevea brasiliensis genome provides new tools for genomic‐assisted breeding and valuable loci to elevate rubber yield. Plant Biotechnology Journal (2023).
3. The rubber tree genome reveals new insights into rubber production and species adaptation. Nature Plants (2016).
4. Identification and reconstitution of the rubber biosynthetic machinery on rubber particles from Hevea brasiliensis. eLife (2016).
5. Biosynthesis of Natural Rubber: Current State and Perspectives. International Journal of Molecular Sciences (2018).
6. Genome analysis of Taraxacum kok-saghyz Rodin provides new insights into rubber biosynthesis. National Science Review (2017).
7. The rubber tree genome shows expansion of gene family associated with rubber biosynthesis. Scientific Reports (2016).