Molecular Mechanisms of Natural Rubber Biosynthesis

2020 ◽  
Vol 89 (1) ◽  
pp. 821-851 ◽  
Author(s):  
Satoshi Yamashita ◽  
Seiji Takahashi
Keyword(s):  
Natural Rubber ◽  
Biosynthetic Pathway ◽  
Molecular Mechanisms ◽  
Rubber Tree ◽  
Lipid Monolayer ◽  
Rubber Biosynthesis ◽  
Key Enzyme ◽  
Membrane Bound ◽  
Natural Rubber Biosynthesis ◽  
Natural Hydrocarbon

Natural rubber (NR), principally comprising cis-1,4-polyisoprene, is an industrially important natural hydrocarbon polymer because of its unique physical properties, which render it suitable for manufacturing items such as tires. Presently, industrial NR production depends solely on latex obtained from the Pará rubber tree, Hevea brasiliensis. In latex, NR is enclosed in rubber particles, which are specialized organelles comprising a hydrophobic NR core surrounded by a lipid monolayer and membrane-bound proteins. The similarity of the basic carbon skeleton structure between NR and dolichols and polyprenols, which are found in most organisms, suggests that the NR biosynthetic pathway is related to the polyisoprenoid biosynthetic pathway and that rubber transferase, which is the key enzyme in NR biosynthesis, belongs to the cis-prenyltransferase family. Here, we review recent progress in the elucidation of molecular mechanisms underlying NR biosynthesis through the identification of the enzymes that are responsible for the formation of the NR backbone structure.

scholarly journals Identification and Characterization of Glycoproteins and Their Responsive Patterns upon Ethylene Stimulation in the Rubber Latex

2020 ◽  
Vol 21 (15) ◽  
pp. 5282 ◽  
Author(s):  
Li Yu ◽  
Boxuan Yuan ◽  
Lingling Wang ◽  
Yong Sun ◽  
Guohua Ding ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Mevalonate Pathway ◽  
Interaction Analysis ◽  
Rubber Tree ◽  
Protein Isoforms ◽  
Wild Type Plant ◽  
Rubber Latex ◽  
Rubber Biosynthesis ◽  
In The Wild ◽  
Natural Rubber Biosynthesis

Natural rubber is an important industrial material, which is obtained from the only commercially cultivated rubber tree, Hevea brasiliensis. In rubber latex production, ethylene has been extensively used as a stimulant. Recent research showed that post-translational modifications (PTMs) of latex proteins, such as phosphorylation, glycosylation and ubiquitination, are crucial in natural rubber biosynthesis. In this study, comparative proteomics was performed to identify the glycosylated proteins in rubber latex treated with ethylene for different days. Combined with Pro-Q Glycoprotein gel staining and mass spectrometry techniques, we provided the first visual profiling of glycoproteomics of rubber latex and finally identified 144 glycosylated protein species, including 65 differentially accumulated proteins (DAPs) after treating with ethylene for three and/or five days. Gene Ontology (GO) functional annotation showed that these ethylene-responsive glycoproteins are mainly involved in cell parts, membrane components and metabolism. Pathway analysis demonstrated that these glycosylated rubber latex proteins are mainly involved in carbohydrate metabolism, energy metabolism, degradation function and cellular processes in rubber latex metabolism. Protein–protein interaction analysis revealed that these DAPs are mainly centered on acetyl-CoA acetyltransferase and hydroxymethylglutaryl-CoA synthase (HMGS) in the mevalonate pathway for natural rubber biosynthesis. In our glycoproteomics, three protein isoforms of HMGS2 were identified from rubber latex, and only one HMGS2 isoform was sharply increased in rubber latex by ethylene treatment for five days. Furthermore, the HbHMGS2 gene was over-expressed in a model rubber-producing grass Taraxacum Kok-saghyz and rubber content in the roots of transgenic rubber grass was significantly increased over that in the wild type plant, indicating HMGS2 is the key component for natural rubber production.

NATURAL RUBBER BIOSYNTHESIS: STILL A MYSTERY

2018 ◽  
Vol 91 (4) ◽  
pp. 683-700 ◽  
Author(s):  
Judit E. Puskas ◽  
Carin A. Helfer
Keyword(s):  
Natural Rubber ◽  
Rubber Tree ◽  
Rubber Biosynthesis ◽  
Attractive Option ◽  
Living Carbocationic Polymerization ◽  
Heat Dispersion ◽  
Mechanism And Kinetics ◽  
Increasing Demand ◽  
Natural Rubber Biosynthesis ◽  
Kinetics Of

ABSTRACT Currently, Hevea brasiliensis (the Brazilian rubber tree) is the only commercially available source of natural rubber (NR) for use in many products, which vary from tires to medical products such as adhesive bandages. H. brasiliensis NR is used in these products because after vulcanization, superior properties, which include elasticity, abrasion resistance, and efficient heat dispersion, result. Issues, such as increasing demand and risk of a single source, make a synthetic (manmade) NR an attractive option. However, after years of research efforts, the exact structure of high-molecular-weight NR is still unproven, and a synthetic NR with similar properties to H. brasiliensis NR still has not been developed. To create a replacement synthetic rubber for H. brasiliensis NR, we believe an understanding of NR biosynthesis is necessary. We present a view of NR biosynthesis from a polymer chemistry viewpoint that is based on insight into the mechanism and kinetics of living carbocationic polymerization.

scholarly journals Regulatory Potential of bHLH-Type Transcription Factors on the Road to Rubber Biosynthesis in Hevea brasiliensis

Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 674
Author(s):  
Tomoko Yamaguchi ◽  
Yukio Kurihara ◽  
Yuko Makita ◽  
Emiko Okubo-Kurihara ◽  
Ami Kageyama ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Natural Rubber ◽  
Hevea Brasiliensis ◽  
Time Course ◽  
Molecular Mechanisms ◽  
Cultured Cells ◽  
Early Stage ◽  
Rubber Biosynthesis ◽  
On The Road

Natural rubber is the main component of latex obtained from laticifer cells of Hevea brasiliensis. For improving rubber yield, it is essential to understand the genetic molecular mechanisms responsible for laticifer differentiation and rubber biosynthesis. Jasmonate enhances both secondary laticifer differentiation and rubber biosynthesis. Here, we carried out time-course RNA-seq analysis in suspension-cultured cells treated with methyljasmonic acid (MeJA) to characterize the gene expression profile. Gene Ontology (GO) analysis showed that the term “cell differentiation” was enriched in upregulated genes at 24 h after treatment, but inversely, the term was enriched in downregulated genes at 5 days, indicating that MeJA could induce cell differentiation at an early stage of the response. Jasmonate signaling is activated by MYC2, a basic helix–loop–helix (bHLH)-type transcription factor (TF). The aim of this work was to find any links between transcriptomic changes after MeJA application and regulation by TFs. Using an in vitro binding assay, we traced candidate genes throughout the whole genome that were targeted by four bHLH TFs: Hb_MYC2-1, Hb_MYC2-2, Hb_bHLH1, and Hb_bHLH2. The latter two are highly expressed in laticifer cells. Their physical binding sites were found in the promoter regions of a variety of other TF genes, which are differentially expressed upon MeJA exposure, and rubber biogenesis-related genes including SRPP1 and REF3. These studies suggest the possibilities that Hb_MYC2-1 and Hb_MYC2-2 regulate cell differentiation and that Hb_bHLH1 and Hb_bHLH2 promote rubber biosynthesis. We expect that our findings will help to increase natural rubber yield through genetic control in the future.

scholarly journals Transcript Profiling Provides Insights into the Molecular Mechanisms of Harvesting-activated Latex Regeneration in Virgin Rubber Trees

2021 ◽  
Author(s):  
Yujie Fan ◽  
Xiaohu Xiao ◽  
Jianghua Yang ◽  
Jiyan Qi ◽  
Yi Zhang ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Tricarboxylic Acid Cycle ◽  
Rubber Tree ◽  
Transcript Profiling ◽  
Raw Material ◽  
Limiting Factors ◽  
Pcr Analysis ◽  
Rt Pcr ◽  
Rubber Biosynthesis ◽  
Latex Regeneration

Abstract Background: Natural rubber, an important industrial raw material with wide applications, is harvested in the form of latex (cytoplasm of rubber-producing laticifers) from Hevea brasiliensis (para rubber tree) by the way of tapping, i.e. removing a slice of trunk bark by a special knife. In regularly tapped rubber trees, latex regeneration consists of one of the main yield-limiting factors for rubber productivity. Conspicuous stimulation on latex production for the first few tappings makes virgin (untapped before) rubber trees an ideal model to investigate the regulatory mechanisms of latex regeneration. To understand the underlying mechanisms, genome-wide transcript profiling was conducted with a silver-staining cDNA-AFLP technology against the latex samples for the first five tappings.Results: A total of 505 non-redundant differentially expressed (DE) transcript-derived fragments (TDFs) were identified, of which 217 were up-regulated, 180 down-regulated, and 108 bell type-regulated among the five tappings. About 72.5% of these DE-TDFs were functionally annotated, and classified into 11 functional categories, which were discussed with reference to harvesting-stimulated latex regeneration. The importance of sugar metabolism and rubber biosynthesis was highlighted, due to the fact that most of the DE-TDFs annotated in sucrose transport, sugar catabolism, glycolysis, tricarboxylic acid cycle and pentose-phosphate pathway and nine of the ten rubber biosynthesis pathway DE-TDFs were up-regulated by the tapping treatment. More than one tenth of the total DE-TDFs were randomly selected for expression validation by semi-quantitative RT-PCR, and 83.8% showed patterns consistent with their original cDNA-AFLP gel profiles. Moreover, quantitative RT-PCR analysis revealed an 89.7% consistency for the 29 latex-regeneration related DE-TDFs examined.Conclusions: In brief, our results indicate the tapping treatment incurs extensive physiological and molecular changes in the laticifers of virgin rubber trees. The vast numbers of tapping-responsive DE-TDFs identified here provide a basis for unravelling the gene regulatory network for latex regeneration in regularly harvested rubber trees.

scholarly journals A Lettuce (Lactuca sativa) Homolog of Human Nogo-B Receptor Interacts withcis-Prenyltransferase and Is Necessary for Natural Rubber Biosynthesis

2014 ◽  
Vol 290 (4) ◽  
pp. 1898-1914 ◽  
Author(s):  
Yang Qu ◽  
Romit Chakrabarty ◽  
Hue T. Tran ◽  
Eun-Joo G. Kwon ◽  
Moonhyuk Kwon ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Lactuca Sativa ◽  
Rubber Biosynthesis ◽  
Natural Rubber Biosynthesis
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