$$\Delta {{\overline {\mu {\text{H}}} }^{{\text{ + }}}}$$ -Controlled Reversible Fluxes of H+ and Calcium at the Tonoplast but Quasi-Total Citrate Sequestration within the Intact Vacuoles from the Latex Cells of Hevea Brasiliensis. Implications in the Production of Natural Rubber

ABSTRACT Protein effect on vulcanization of NR, obtained from Hevea brasiliensis, was investigated by analyzing the crosslinking structure of the resulting vulcanizates prepared from untreated NR, deproteinized natural rubber (DPNR), and protein-free natural rubber (PFNR) by swelling methods and rubber-state NMR spectroscopy. The proteins present in NR were removed by three methods: deproteinization with enzyme, urea, or urea–acetone in the presence of sodium dodecyl sulfate. The amount of proteins present in NR, approximately 0.238 w/w%, was reduced to 0.000 w/w% by urea–acetone deproteinization, whereas it was reduced to approximately 0.003 and 0.019 w/w% by enzyme and urea deproteinizations, respectively. Hardness, swelling degree, and crosslinking structure depended on the amount of proteins. Changes in mechanical properties for the vulcanizates prepared from not only non-filler compounds but also carbon black–filled and silica-filled compounds were attributed to the amount of proteins.

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Obtaining of hairy roots cultures of kok-saghyz and analysis of the content of natural rubber

Biomics ◽

10.31301/2221-6197.bmcs.2020-36 ◽

2020 ◽

Vol 12 (4) ◽

pp. 449-454

Author(s):

B.R. Kuluev ◽

G.R. Gumerova ◽

A.V. Knyazev ◽

Kh.G. Musin ◽

A.V. Chemeris

Keyword(s):

Natural Rubber ◽

Hairy Roots ◽

Industrial Production ◽

Hevea Brasiliensis ◽

Dry Weight ◽

Hexane Extract ◽

Raw Material ◽

Stress Factors ◽

Special Equipment ◽

High Quality

Kok-saghyz (Taraxacum kok-saghyz Rodin) is an alternative to Hevea brasiliensis source of high quality natural rubber that is able to grow in temperate climates. However, the field cultivation of kok-saghyz is associated with a number of problems, such as the need for seed stratification, seedlings that are very sensitive to stress factors, laboriousness in the fight against weeds and pests, uneven maturation of seeds, the lack of special equipment for sowing, collecting roots and seeds. In this regard, the use of hairy roots of kok-saghyz as a raw material for obtaining natural rubber seems to be promising. The aim of our work was to obtain cultures of hairy roots of kok-saghyz and to determine the content of natural rubber in them by the hexane method. In the course of the work, 10 lines of hairy roots of kok-saghyz were obtained, capable of growing in isolated cultures. It has been shown that these hairy roots accumulate an average of 7.5% hexane extract (rubber-like substances) per dry weight, which is about 1.5 times more than the roots of field kok-saghyz. Our data indicate that the use of the hairy roots of kok-saghyz is promising for the industrial production of natural rubber.

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Lysozymes from natural rubber latex (Hevea brasiliensis): Assay development and recovery using ammonium sulphate and surfactant precipitations

Industrial Crops and Products ◽

10.1016/j.indcrop.2021.114470 ◽

2022 ◽

Vol 177 ◽

pp. 114470

Author(s):

Yong Yee Seng ◽

Chen Tzi Yun ◽

Nurulhuda Abdullah ◽

Fadzlie Wong Faizal Wong

Keyword(s):

Natural Rubber ◽

Ammonium Sulphate ◽

Hevea Brasiliensis ◽

Natural Rubber Latex ◽

Assay Development ◽

Rubber Latex

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

Plants ◽

10.3390/plants9060674 ◽

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.

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