Articoli di riviste: "Hevea brasiliensis latex"

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Bourrain, JL. "Hevea brasiliensis Rather Than Latex". Journal of Investigational Allergology and Clinical Immunology 26, n. 4 (30 luglio 2016): 278. http://dx.doi.org/10.18176/jiaci.0067.

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Glushakova, A. M., A. V. Kachalkin, I. A. Maksimova e I. Yu Chernov. "Yeasts in Hevea brasiliensis latex". Microbiology 85, n. 4 (luglio 2016): 488–92. http://dx.doi.org/10.1134/s002626171604007x.

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Liengprayoon, Siriluck, Klanarong Sriroth, Eric Dubreucq e Laurent Vaysse. "Glycolipid composition of Hevea brasiliensis latex". Phytochemistry 72, n. 14-15 (ottobre 2011): 1902–13. http://dx.doi.org/10.1016/j.phytochem.2011.04.023.

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HUANRALUEK, NARUEMON, CHAYANARD PHUKHAMSAKDA, CHANOKNED SENWANNA, SINANG HONGSANAN, RUVISHIKA S. JAYAWARDENA, DARBHE J. BHAT e KEVIN D. HYDE. "Verruconis heveae, a novel species from Hevea brasiliensis in Thailand". Phytotaxa 403, n. 1 (9 maggio 2019): 47. http://dx.doi.org/10.11646/phytotaxa.403.1.4.

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Verruconis heveae, a new species accommodated in Sympoventuriaceae was isolated from dried latex on bark of a rubber tree (Hevea brasiliensis) collected from Phayao Province, Thailand. The comparison of its morphological characters distinguished V. heveae from other Verruconis species by having brown, woolly mycelium on the natural substrate and solitary, ellipsoidal to subglobose, 1–3 septate conidia. Phylogenetic analysis of a combined LSU and ITS dataset revealed a distinct lineage within Sympoventuriaceae.

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Lynam, Joan G., Holden T. Zugger e Elizabeth T. Amedee. "Ionic Liquids Separating Rubber Latex from Guayule". Materials 14, n. 15 (30 luglio 2021): 4255. http://dx.doi.org/10.3390/ma14154255.

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Danger to rubber trees (Hevea brasiliensis) from South American leaf blight fungus imperils the world’s source of natural latex for essential rubber products. Avoiding latex allergies also requires a non-Hevea latex source. The present methods for removing latex entrapped in the individual cells of guayule plants require environmentally hazardous chemicals. This study proposes a new method for latex extraction from guayule using various ionic liquids (ILs) to dissolve cell walls and release latex, as substantiated by Fourier transform infrared spectroscopy (FTIR) data.

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Cardona, R., e J. Sánchez. "Reply to “Hevea brasiliensis Rather Than Latex”". Journal of Investigational Allergology and Clinical Immunology 26, n. 4 (30 luglio 2016): 278. http://dx.doi.org/10.18176/jiaci.0071.

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Akasawa, Akira, Li-Shan Hsieh e Yuan Lin. "Serum reactivities to latex proteins (Hevea brasiliensis)". Journal of Allergy and Clinical Immunology 95, n. 6 (giugno 1995): 1196–205. http://dx.doi.org/10.1016/s0091-6749(95)70076-5.

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Tao, Jinlong, Dongning He, Bin Tang, Lingxue Kong, Yongyue Luo, Pengfei Zhao, Wei Gong e Zheng Peng. "In situ synthesis of natural rubber latex-supported gold nanoparticles for flexible SERS substrates". RSC Advances 5, n. 61 (2015): 49168–74. http://dx.doi.org/10.1039/c5ra05681k.

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Wang, Xue, Wen-Cheng Liu, Xue-Wei Zeng, Sa Yan, Yi-Min Qiu, Jin-Bo Wang, Xi Huang e Hong-Mei Yuan. "HbSnRK2.6 Functions in ABA-Regulated Cold Stress Response by Promoting HbICE2 Transcriptional Activity in Hevea brasiliensis". International Journal of Molecular Sciences 22, n. 23 (24 novembre 2021): 12707. http://dx.doi.org/10.3390/ijms222312707.

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Low temperature remarkably limits rubber tree (Hevea brasiliensis Muell. Arg.) growth, latex production, and geographical distribution, but the underlying mechanisms of Hevea brasiliensis cold stress response remain elusive. Here, we identified HbSnRK2.6 as a key component in ABA signaling functions in phytohormone abscisic acid (ABA)-regulated cold stress response in Hevea brasiliensis. Exogenous application of ABA enhances Hevea brasiliensis cold tolerance. Cold-regulated (COR) genes in the CBF pathway are upregulated by ABA. Transcript levels of all five HbSnRK2.6 members are significantly induced by cold, while HbSnRK2.6A, HbSnRK2.6B, and HbSnRK2.6C can be further activated by ABA under cold conditions. Additionally, HbSnRK2.6s are localized in the cytoplasm and nucleus, and can physically interact with HbICE2, a crucial positive regulator in the cold signaling pathway. Overexpression of HbSnRK2.6A or HbSnRK2.6B in Arabidopsis extensively enhances plant responses to ABA and expression of COR genes, leading to increased cold stress tolerance. Furthermore, HbSnRK2.6A and HbSnRK2.6B can promote transcriptional activity of HbICE2, thus, increasing the expression of HbCBF1. Taken together, we demonstrate that HbSnRK2.6s are involved in ABA-regulated cold stress response in Hevea brasiliensis by regulating transcriptional activity of HbICE2.

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Yun, Yang, Zhang Zhi-Li, Liu Kuan-Can, Li Wei-Guo e Su Huo-Sheng. "Cloning and characteristics of a novel gene HbUEP from latex in Hevea brasiliensis". Chinese Journal of Agricultural Biotechnology 5, n. 2 (agosto 2008): 165–68. http://dx.doi.org/10.1017/s1479236208002337.

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AbstractHbUEP, an ubiquitin extension protein gene from latex of the rubber tree (Hevea brasiliensis) was cloned and sequenced using a differentially ethphon-induced expressed cDNA subtraction library. The cDNA had 771 bp nucleotides, comprising a 226 bp 3′ untranslated region (UTR), 77 bp 5′UTR and a 468 bp open reading frame encoding a 156 amino acid peptide. Southern blotting analysis showed that this gene was a low copy number gene in the H. brasiliensis genome. Within 24 h after application of ethphon, the gene was expressed weakly in both control and latex sampled at 6 h, and strongly in latex sampled at 12 h, showing that this gene expression could be regulated by ethphon. Ethphon could increase the latex yield in H. brasiliensis. It is suggested that the HbUEP gene may be involved in the regulation of ethphon-induced high latex yield in H. brasiliensis.

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Cornish, Katrina, Jali Williams, Julie L. Hall e Raymond G. McCoy. "Production and Properties of Yulex® - The Natural Solution to Latex Allergy". Rubber Chemistry and Technology 81, n. 4 (1 settembre 2008): 709–22. http://dx.doi.org/10.5254/1.3548227.

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Abstract Natural rubber is an irreplaceable raw material vital to industry, transportation, medicine and defense, largely produced from clonal plantations of Hevea brasiliensis in Southeast Asia. Additional rubber-producing crops are greatly desired to increase biodiversity, protect supplies, and provide a safe alternative for people suffering from Type I latex protein allergy. Basic and applied research approaches were used to make the production of latex (Yulex® latex) from Parthenium argentatum (guayule) a commercial reality. In contrast to Hevea brasiliensis, from which rubber latex is tapped by hand from laticifers, guayule latex rubber is contained within individual bark parenchyma cells. Processing involves disrupting these cells to release the rubber particles, and then purifying the latex. As in the Hevea industry, latex concentration can be achieved by centrifugation and/or by creaming agents. An artificially produced guayule natural rubber latex is then produced, under the material name of “Yulex® latex”. The Yulex Pilot Plant has been constructed, optimized and automated, and extracts then purifies latex from guayule shrub without detectable losses. The natural rubber polymers in guayule latex are high molecular weight and products made from this material have the desired high performance properties. Because guayule latex contains very little protein, all of which is hydrophobic and bound to the rubber phase, and because none of the protein cross-reacts with Type I latex allergy to Hevea latex products, its use is initially aimed towards the high-value medical products marketplace. Clinical and performance trials continue to ensure that guayule processing provides a safe, high performance, non-allergenic natural rubber latex that is safe for human use.

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Habib, Mohd Afiq Hazlami, Gan Chee Yuen, Fazilah Othman, Nurul Nabilah Zainudin, Aishah Abdul Latiff e Mohd Nazri Ismail. "Proteomics analysis of latex from Hevea brasiliensis (clone RRIM 600)". Biochemistry and Cell Biology 95, n. 2 (aprile 2017): 232–42. http://dx.doi.org/10.1139/bcb-2016-0144.

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The natural rubber latex extracted from the bark of Hevea brasiliensis plays various important roles in today’s modern society. Following ultracentrifugation, the latex can be separated into 3 layers: C-serum, lutoids, and rubber particles. Previous studies have shown that a large number of proteins are present in these 3 layers. However, a complete proteome for this important plant is still unavailable. Protein sequences have been recently translated from the completed draft genome database of H. brasiliensis, leading to the creation of annotated protein databases of the following H. brasiliensis biosynthetic pathways: photosynthesis, latex allergens, rubberwood formation, latex biosynthesis, and disease resistance. This research was conducted to identify the proteins contained within the latex by way of de novo sequencing from mass spectral data obtained from the 3 layers of the latex. Peptides from these proteins were fragmented using collision-induced dissociation, higher-energy collisional dissociation, and electron-transfer dissociation activation methods. A large percentage of proteins from the biosynthetic pathways (63% to 100%) were successfully identified. In addition, a total of 1839 unique proteins were identified from the whole translated draft genome database (AnnHBM).

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Habib, Mohd Afiq Hazlami, Chee-Yuen Gan, Aishah Abdul Latiff e Mohd Nazri Ismail. "Unrestrictive identification of post-translational modifications in Hevea brasiliensis latex". Biochemistry and Cell Biology 96, n. 6 (dicembre 2018): 818–24. http://dx.doi.org/10.1139/bcb-2018-0020.

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The natural rubber latex extracted from the bark of Hevea brasiliensis plays various important roles in modern society. Post-translational modifications (PTMs) of the latex proteins are important for the stability and functionality of the proteins. In this study, latex proteins were acquired from the C-serum, lutoids, and rubber particle layers of latex without using prior enrichment steps; they were fragmented using collision-induced dissociation (CID), higher-energy collisional dissociation (HCD), and electron-transfer dissociation (ETD) activation methods. PEAKS 7 were used to search for unspecified PTMs, followed by analysis through PTM prediction tools to crosscheck both results. There were 73 peptides in 47 proteins from H. brasiliensis protein sequences derived from UniProtKB were identified and predicted to be post-translationally modified. The peptides with PTMs identified include phosphorylation, lysine acetylation, N-terminal acetylation, hydroxylation, and ubiquitination. Most of the PTMs discovered have yet to be reported in UniProt, which would provide great assistance in the research of the functional properties of H. brasiliensis latex proteins, as well as being useful biomarkers. The data are available via the MassIVE repository with identifier MSV000082419.

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Han, K. H., D. H. Shin, J. Yang, I. J. Kim, S. K. Oh e K. S. Chow. "Genes expressed in the latex of Hevea brasiliensis". Tree Physiology 20, n. 8 (1 aprile 2000): 503–10. http://dx.doi.org/10.1093/treephys/20.8.503.

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Giordani, Roger, Sélima Benyahia, Marcel Teissère e Georges Noat. "Purification and properties of from Hevea brasiliensis latex". Plant Science 84, n. 1 (gennaio 1992): 25–34. http://dx.doi.org/10.1016/0168-9452(92)90204-y.

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Nurnaini, Novita Indah, Muhammad Helmi e Arfa Agustina Rezekiah. "ANALISIS NILAI GUNA PERKEBUNAN KARET (Hevea brasiliensis) PADA PT. PERMATA ENAM NUSANTARA". Jurnal Sylva Scienteae 4, n. 4 (27 agosto 2021): 646. http://dx.doi.org/10.20527/jss.v4i4.3940.

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The purpose of this study are: (1) Analyzing the direct use value of rubber plants (Hevea brasiliensis) in the form of economic value of wood and the value of gum, (2) Analyzing the indirect use value of rubber plants (Hevea brasiliensis) in the form of economic value of carbon sinks, (3) Calculate the total value of the use of rubber plants (Hevea brasiliensis). The results of the study showed that the direct use value had the most influence on the total use value in the plantation with a percentage level of 88.55% far adrift compared to the indirect use value of 11.45%, this is because the direct use value had parameters namely rubber wood production and rubber latex while in the indirect use value there is only one parameter used and can also be caused by differences in the assumptions used in quantitative.Tujuan dari penelitian ini adalah: (1) Menganalisis nilai guna langsung tanaman karet (Hevea brasiliensis) berupa nilai ekonomi kayu dan nilai getah, (2) Menganalisis nilai guna tidak langsung tanaman karet (Hevea brasiliensis) berupa nilai ekonomi penyerap karbon, (3) Menghitung besarnya total nilai guna tanaman karet (Hevea brasiliensis). Metode yang digunakan yaitu Purposive Sampling untuk penentuan sampel dengan inventarisasi menggunakan plot lingkaran dan metode Sensus untuk responden. Hasil pada penelitian menunjukkan bahwa nilai guna langsung paling berpengaruh pada total nilai guna di perkebunan tersebut dengan tingkat persentase 88,55% terpaut jauh dibandingkan nilai guna tidak langsung yaitu 11,45%, hal ini dikarenakan pada nilai guna langsung memiliki parameter yaitu produksi kayu karet dan getah karet sedangkan pada nilai guna tidak langsung hanya terdapat satu parameter yang digunakan dan dapat pula disebabkan oleh perbedaan asumsi-asumsi yang digunakan dalam mengkuantitatifkan.

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Buakong, Wanphen, Pluang Suwanmanee, Thanika Vasinayanuwatana, Kedsirin Ruttajorn, Kasem Assawatreeratanakul e John Espie Leake. "Characterization and Expression Analysis of HbC3H66: Implications for Transcriptional Regulation in Rubber Biosynthesis and Abiotic Stress Responses in Hevea brasiliensis". Trends in Sciences 20, n. 12 (13 settembre 2023): 6835. http://dx.doi.org/10.48048/tis.2023.6835.

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CCCH-type zinc-finger protein (ZnF_CCCH) family is one of the most important transcription factors (TFs) linked to various biotic and abiotic stressors and physiological and developmental processes in plants. This study aims to clone and characterise the latex gene expression patterns, evolution and characteristics of the Hevea brasiliensis ZnF_CCCH domain-containing protein 66 (HbC3H66) gene. These results showed that the open reading frame (ORF) of the HbC3H66 gene was 2,106 bp, encoding 701 aa and the calculated molecular weight of the encoded protein was 76.52 kDa. The N-terminal region of HbC3H66 contains 2 ANK repeats in, PfK_2/FBPase-2 and 2 type zinc finger motifs. Phylogenetic analysis showed that the C3H66 amino acid from Hevea and other plant C3H66 were clustered into 1 group and could be used for evolutionary analysis. Semi-quantitative RT-PCR (sqRT-PCR) revealed that the HbC3H66 mRNA was abundance in high-yielding Hevea clones (RRIT251 and RRIM600) and treatment with 2.5 % of ethephon (Eth) induced HbC3H66 mRNA expression in the latex of 15 years old Hevea trees. The HbC3H66 gene was induced by water deficit and 0.5 M NaCl in the latex of 3-month-old Hevea. In conclusion, the HbC3H66 protein may play a role in DNA-binding transcriptional regulation in NR pathways. Which would provide a theoretical basis for understanding the evolution and functions of the Hevea C3H66 gene in rubber biosynthesis. HIGHLIGHTS CCCH-type zinc-finger proteins (ZnF_CCCH) are essential transcription factors (TFs) for protein binding activity in plant growth and stress tolerance. Hevea brasiliensis zinc finger CCCH domain-containing protein 66 (HbC3H66) gene was clone and characterized. HbC3H66 contains 2 ANK repeat in, Pfk_2/FBPase-2 and 2 type zinc finger motifs. Semi-quantitative RT-PCR revealed that HbC3H66 gene was abundance in high-yielding Hevea clones (RRIT251 and RRIM600) and ethylene was induced HbC3H66 mRNA expression in the latex of Hevea The HbC3H66 gene was induced by water deficit and 0.5 M NaCl in the latex of seedling of Hevea trees. The HbC3H66 protein play a role in DNA-binding transcriptional regulation in NR pathway. GRAPHICAL ABSTRACT

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Andriyanto, Mochlisin, Andi Wijaya, Junaidi . e Arief Rachmawan. "PRODUKSI TANAMAN KARET (Hevea brasiliensis) PADA WAKTU PENGUMPULAN LATEKS YANG BERBEDA". Jurnal Agro Estate 3, n. 1 (2 luglio 2019): 27–34. http://dx.doi.org/10.47199/jae.v3i1.18.

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Latex is a colloidal suspended of rubber particle in rubber tree (Hevea brasiliensis). Technically, the capacity of rubber productivity can be determined by latex collectionperiod after being tapped. The objective of research was to obtain the differences of latex collection period. The study was conducted in September-November 2017 at the Sungei Putih Research Center in Experimental Estate with PB 260 (7 years tapped) on BO-2 (S/2 d3.ET2.5% Ga1.0 6/y(m)).The experimental designused a Randomized Block Design (RBD) with four treatments of latex collection periodi.e 20, 40, 60, 80 minutes after being tapped with three replicates respectively. The parameters observed was gram/tree/tapping (g/p/s), kg/ha/years, latex flow rate (ml/minutes) and total solid content (%).The results showed that latex collection period was significantly different to g/p/s, kg/ha/years and latex flow rate. Total solid content (TSC) was not significantlydifferent in all treatments. The latex collection period of 20 minutes after being tapped had higher productivity than 40, 60, 80 minutes.

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Andriyanto, Mochlisin, Andi Wijaya, Junaidi e Arief Rachmawan. "PRODUKSI TANAMAN KARET (Hevea brasiliensis) PADA WAKTU PENGUMPULAN LATEKS YANG BERBEDA". Jurnal Agro Estate 3, n. 1 (7 febbraio 2019): 27–34. http://dx.doi.org/10.47199/jae.v3i1.61.

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Latex is a colloidal suspended of rubber particle in rubber tree (Hevea brasiliensis). Technically, the capacity of rubber productivity can be determined by latex collectionperiod after being tapped. The objective of research was to obtain the differences of latex collection period. The study was conducted in September-November 2017 at the Sungei Putih Research Center in Experimental Estate with PB 260 (7 years tapped) on BO-2 (S/2 d3.ET2.5% Ga1.0 6/y(m)).The experimental designused a Randomized Block Design (RBD) with four treatments of latex collection periodi.e 20, 40, 60, 80 minutes after being tapped with three replicates respectively. The parameters observed was gram/tree/tapping (g/p/s), kg/ha/years, latex flow rate (ml/minutes) and total solid content (%).The results showed that latex collection period was significantly different to g/p/s, kg/ha/years and latex flow rate. Total solid content (TSC) was not significantlydifferent in all treatments. The latex collection period of 20 minutes after being tapped had higher productivity than 40, 60, 80 minutes.

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Isarangkool Na Ayutthaya, S., e F. C. Do. "LATEX YIELD OF HEVEA BRASILIENSIS POORLY INDICATES SOIL DROUGHT". Acta Horticulturae, n. 1099 (settembre 2015): 865–72. http://dx.doi.org/10.17660/actahortic.2015.1099.110.

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Chow, Keng-See, Mohd Noor Mat-Isa, Azlina Bahari, Ahmad-Kamal Ghazali, Halimah Alias, Zainorlina Mohd.-Zainuddin, Chee-Choong Hoh e Kiew-Lian Wan. "Metabolic routes affecting rubber biosynthesis in Hevea brasiliensis latex". Journal of Experimental Botany 63, n. 5 (7 dicembre 2011): 1863–71. http://dx.doi.org/10.1093/jxb/err363.

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Nawamawat, Kanjanee, Jitladda T. Sakdapipanich, Chee C. Ho, Yujie Ma, Jing Song e Julius G. Vancso. "Surface nanostructure of Hevea brasiliensis natural rubber latex particles". Colloids and Surfaces A: Physicochemical and Engineering Aspects 390, n. 1-3 (ottobre 2011): 157–66. http://dx.doi.org/10.1016/j.colsurfa.2011.09.021.

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Gebi Hiskia, Akhmad Sopian e Mahdalena. "THE EFFECT OF UREA, KCl, SP-36 FERTILIZER ON PRODUCTION AT SOME AGE OF NATURAL RUBBER PLANT (Hevea brasiliensis Mull.Arg)". Agrifarm : Jurnal Ilmu Pertanian 11, n. 1 (30 luglio 2022): 55–60. http://dx.doi.org/10.24903/ajip.v11i1.1510.

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Gebi Hiskia Anggraini, Faculty of Agriculture, Widya Gama Mahakam University Samarinda 2020, " The Effect Of Urea, Kcl, Sp-36 Fertilizer On Production At Some Age Of Natural Rubber Plant (Hevea Brasiliensis Mull.Arg)" under the guidance of Mahdalena and Akhmad Sopian. The purpose of this study was to determine the correct dosage of fertilizer to increase the production of natural rubber plants, to determine the effect of rubber plant age and the combination of Urea, KCl, SP-36 fertilizers on increased production,this research was conducted for 3 months, from March 2020 to July 2020. The research location was in a rubber plantation located in Tondoh Village The study used a divided plot design or divided plot consisting of 2 factors with 3 replications, the main plot factor was the age of the rubber plant which consisted of 2 levels of age 8 years and 10 years, the second factor of the sub-plots was Fertilizer consisting of 5 levels, namely: P0 = Without fertilizer, P1 = Urea fertilizer 350 g, KCl 300 g, SP36 260 g / tree, P2 = KCl fertilizer 300 g, SP36 260 g / tree, P3 = Urea fertilizer 350 g, SP36 260 g / tree, P4 = Urea fertilizer 350 g, KCl 300 g / tree The results showed that the application of Urea, KCl, SP-36 fertilizers had a significant effect on latex productivity, latex wet weight, and latex dry weight on the production of rubber (Hevea brasiliensis Muell. Agr). At the age of 8 years and 10 years with the combination of Urea, KCl, SP-36 Fertilizer treatment did not manifest a significant effect on the results of Production, Wet Weight, Dry Weight, and Dry Rubber Content Dry Rubber Content Natural rubber (Hevea brasiliensis Muell. Agr) belongs to quality II which has a low Dry Rubber content that means that the water content in the latex is relatively high Key words: Latex and Inorganic

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Sakdapipanich, Jitladda, Kittipong Insom e Nataphon Phupewkeaw. "Composition of Color Substances of Hevea Brasiliensis Natural Rubber". Rubber Chemistry and Technology 80, n. 2 (1 maggio 2007): 212–30. http://dx.doi.org/10.5254/1.3539403.

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Abstract It is accepted that NR gives naturally occurring color, which restrict many applications such as light-color products. Therefore, characterization of color substances presenting in NR is very useful to develop the certain methodology to eliminate them completely or partly from NR in the future. In this work, an attempt was made to purify and characterize the color substances extracted from various fractions of Hevea rubber latex by certain methods, using high-resolution structural characterization techniques. It was found that the content of color substances extracted from fresh latex (FL), rubber cream, bottom fraction (BF), Frey Wyssling (FW) particles and STR 20 were different. Based on the high-resolution spectroscopic analyzes, it was found that the color substances extracted from NR were composed of carotenoids, tocotrienol esters, fatty alcohol esters, tocotrienols, unsaturated fatty acids, fatty alcohols, diglyceride and monoglyceride. The results will be useful for rubber-technologist to identify the origin to make obnoxious color in natural rubber, especially in some applications which are restricted by such the color.

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Liebezeit, Gerd, Ralf Wöstmann e Christine Jose. "Biomarkers from Latex Drying Plants in Siak River Sediments". Asian Journal of Water, Environment and Pollution 6, n. 2 (gennaio 2009): 1–5. http://dx.doi.org/10.3233/ajw-2009-6_2_01.

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In Pekanbaru, Riau Province, Sumatra, two latex processing plants discharge wastewater rich in particulate and dissolved organic matter to the Siak river. The immediate effect is a marked enrichment of total organic carbon in the sediment adjacent to the discharge point. Biomarkers specific for Hevea brasiliensis were also found in the discharged process water. These compounds could be detected up to 25 km downstream.

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Kostyal, David, Kelly Horton, Donald Beezhold, Suzanne Lockwood e Robert G. Hamilton. "LATEX AS A SIGNIFICANT SOURCE OF HEVEA BRASILIENSIS ALLERGEN EXPOSURE". Annals of Allergy, Asthma & Immunology 103, n. 4 (ottobre 2009): 354–55. http://dx.doi.org/10.1016/s1081-1206(10)60537-6.

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Lynn, K. R., e N. A. Clevette-Radford. "Hevains: Serine-centred proteases from the latex of Hevea brasiliensis". Phytochemistry 25, n. 10 (gennaio 1986): 2279–82. http://dx.doi.org/10.1016/s0031-9422(00)81679-9.

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Wititsuwannakul, D. "Polyphenol oxidases from latex of Hevea brasiliensis: purification and characterization". Phytochemistry 61, n. 2 (settembre 2002): 115–21. http://dx.doi.org/10.1016/s0031-9422(02)00234-0.

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Van Parijs, Jan, Willem F. Broekaert, Irwin J. Goldstein e Willy J. Peumans. "Hevein: an antifungal protein from rubber-tree (Hevea brasiliensis) latex". Planta 183, n. 2 (gennaio 1991): 258–64. http://dx.doi.org/10.1007/bf00197797.

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Churngchow, Nunta, Ahporn Suntaro e Rapepun Witttsuwannnakul. "β-1,3-glucanase isozymes from the latex of Hevea brasiliensis". Phytochemistry 39, n. 3 (giugno 1995): 505–9. http://dx.doi.org/10.1016/0031-9422(95)00974-c.

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Junaidi, Junaidi. "Transformasi Sistem Pemanenan Latex Tanaman Karet: Review". JURNAL BUDIDAYA PERTANIAN 16, n. 1 (30 giugno 2020): 1–10. http://dx.doi.org/10.30598/jbdp.2020.16.1.1.

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Most people understate that latex harvesting is merely cutting the bark and collecting the sap. Since it was cultivated in the monoculture plantation system, rubber (Hevea brasiliensis) harvesting system has been transformed continually. This article presents the transformation of rubber harvesting systems, tapping innovations that have been developed, and the current condition of rubber agribusiness and its impact on the tapping system applied. At the beginning of the development of the rubber cultivation era, tapping was conducted with multiple slicings to gain high rubber yield. This system turned into one slice to extend the economic span of the plant. The invention of latex stimulants transformed the rubber tapping system from once every two days (d2) without stimulants to once every three days (d3) with stimulants. In the case of the tapping technique, several tapping systems have been developed, including puncture tapping, upward and double-cut tapping, Alternate Tapping System, and Change Over Panel. Except for the puncture tapping, those tapping systems are still used nowadays. Latex diagnosis, that is the measurements of the sucrose, inorganic phosphate, and thiol contents in the latex, became the basis of clonal grouping and the clonal typology tapping system. The current low rubber price renders the adoption of low-frequency tapping systems (d4, d5, or d6) with high dose and frequency of stimulant application. In the future, the low-frequency tapping system will remain the ultimate choice as labor costs continue rising. Besides, the use of sensory technology and digital instruments is being widely studied, which indicates that the latex harvesting system in rubber plants is believed to continue to develop. Keywords: Hevea brasiliensis, latex diagnosis, latex yield, stimulant, tapping ABSTRAK Sebagian besar masyarakat beranggapan bahwa memanen lateks hanya mengiris kulit dan menampung getahnya. Namun sebenarnya, sejak dikembangkan dalam sistem perkebunan monokultur, sistem pemanenan lateks karet (Hevea brasiliensis) terus mengalami pembaharuan. Artikel ini menyajikan transformasi sistem pemanenan lateks tanaman karet, inovasi-inovasi yang pernah dikembangkan, serta kondisi agribisnis karet saat ini dan dampaknya terhadap sistem sadap yang diterapkan. Pada awal perkembangan perkebunan karet, penyadapan dilakukan dengan banyak irisan untuk mendapatkan hasil sebanyak-banyaknya. Ini kemudian berubah menjadi satu irisan untuk memperpanjang umur ekonomis tanaman. Penggunaan stimulan mengubah sistem penyadapan karet dari dua hari sekali (d2) tanpa stimulan menjadi tiga hari sekali (d3) dengan stimulan. Dalam hal teknis, beberapa sistem sadap pernah dikembangkan antara lain, sadap tusuk, penyadapan ke arah atas, sadap ganda, Alternate Tapping System, dan Change Over Panel. Selain sadap tusuk, inovasi-inovasi penyadapan tersebut tetap digunakan sampai saat ini. Diagnosis lateks melalui pengukuran kadar sukrosa, fosfat anorganik, dan thiol dalam lateks, menjadi dasar pengelompokan klon dan penyadapan tipologi klonal. Harga karet yang rendah saat ini menyebabkan perusahaan perkebunan cenderung mengadopsi sistem sadap frekuensi rendah (d4, d5, atau d6) dengan dosis dan frekuensi stimulan yang tinggi. Di masa yang akan datang, sistem sadap frekuensi rendah akan tetap menjadi pilihan utama karena upah tenaga kerja terus meningkat. Selain itu, penggunaan teknologi sensorik dan instrumen digital mulai banyak diteliti. Melihat fakta-fakta ini, sistem pemanenan lateks pada tanaman karet diyakini akan terus berkembang. Kata kunci: diagnosis lateks, Hevea brasiliensis, penyadapan, produksi karet, stimulan

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Amorim, Erick Phelipe, João Roberto Menucelli, Aline Delfino Germano, Rubens Francisco Pereira de Faria, Juraci de Andrade Barbosa, Franciane de Andrade Pádua, Miguel Luiz Menezes de Freitas et al. "Technological potential of fibers from 20 Hevea brasiliensis clones for use as pulp, paper, and composite materials". Research, Society and Development 10, n. 10 (18 agosto 2021): e549101019102. http://dx.doi.org/10.33448/rsd-v10i10.19102.

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Based on the use of Hevea brasiliensis in latex production, the species has a consolidated role in the Brazilian economy. However, at the end of the production cycle, which lasts from 25 to 30 years, resulting wood, in general, has no added value and is normally used for firewood, without further exploring its technological properties. Seeking to introduce this species into the pulp and paper industry, we aimed to determine the fiber quality of 20 commercial clones. Wood samples were collected from planted trees (11 to 12 years old) in the municipality of Selvíria - MS. We calculated wood quality indexes of H. brasiliensis for cellulose and paper, including Flexibility coefficient, Wall proportion, Runkel ratio, Slenderness ratio (Aspect ratio), and Luce's Shape Factor. The fiber quality indexes that best indicate the potential use of wood from Hevea brasiliensis clones for cellulose and paper production were Wall Fraction, Runkel Ratio and Luce's Shape Factor, indicating that H. brasiliensis fibers, if used for proper industrial purposes, will give origin of a rigid paper with greater bonding contact on the surface. The clones that presented better results for fiber quality indexes were IAC 311, IAC 41, IAN 873, IAC 326, IAC 40 and RRIM 725. Enabling the use of wood after the latex exploratory cycle for pulp and paper will serve as a basis for genetic improvement of these clones and expansion of forest plantations for this purpose.

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Francis, Soumahin Eric, Adou Bini Yao Christophe, Tonessia Dolou Charlotte e Obouayeba Samuel. "Production Systems to Minimize the Latex Harvesting Cost of Rubber (Hevea brasiliensis)". European Scientific Journal, ESJ 14, n. 30 (31 ottobre 2018): 190. http://dx.doi.org/10.19044/esj.2018.v14n30p190.

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Latex harvesting is the most costly activity in natural rubber production and the shortage of available skill and unstable latex harvester are the main factor affecting in Rubber cultivation and its lead to increase cost of production. Low frequency system (LFT) with the hormonal stimulation is a solution to solve this problem that minimize the cost of latex harvesting. Therefore, a study was conducted for nine years on production systems that minimize the cost of latex harvesting in southwestern Côte d'Ivoire with clones IRCA 130, GT 1 and PB 217 of Hevea brasiliensis. These production systems differ from each other by an increase in tapping frequency, in comparison with the standard tapping (d3) on the above clones in southwestern Côte d'Ivoire. The results indicated that production systems that minimize the cost of latex harvesting admittedly resulted in losses of rubber yield per hectare per year from 1 to 37%, but improved the yield per tree per tapping as well as the productivity of the tapper from 20 to 46%, in year. Moreover, these systems contributed to the improvement of the vegetative growth of trees and kept the rate of dry trees in low level (less than 7%). Furthermore, these systems also helped to reduce the cost of tapping labor from 1 to 50%, as well as operating costs from 2 to 47%, in comparison with European Scientific Journal October 2018 edition Vol.14, No.30 ISSN: 1857 – 7881 (Print) e - ISSN 1857- 7431 191 the standard tapping (d3). Finally, in the context of a shortage of tapping labor, these systems help increase the farmer’s profit margin from 26% to 113%, as well as the tapper’s income from 26% to 89%. Therefore, it appears that the use of low frequency harvesting system with the appropriate stimulants appears as a solution to minimize latex harvesting cost and unavailability of harvesters in rubber cultivation.

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Gonçalves, Paulo de Souza, Marcelo de Almeida Silva, Ligia Regina Lima Gouvêa e Erivaldo José Scaloppi Junior. "Genetic variability for girth growth and rubber yield in Hevea brasiliensis". Scientia Agricola 63, n. 3 (giugno 2006): 246–54. http://dx.doi.org/10.1590/s0103-90162006000300006.

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Basic knowledge of genetic characteristics of populations is necessary to conduct effective breeding and selection. The objective of this paper is describing the genetic variation of rubber yield and the correlation with other traits, and estimating the genetic parameters for girth growth and total number of latex vessels. Sixty seven clones of Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg. were tested at five sites during 10 years. Characters girth growth at panel opening and rubber yield, showed broad sense heritability on plot mean level, from 0.32 to 0.66 and 0.59 to 0.92, respectively. Predicted genetic gains equal to 0.73 cm and 0.79 g increase respectively on girth and yield in the opening panel and mature phases seems realistic, even with moderate selection intensities. Genetic correlations with rubber yield, bark thickness and total number of latex vessels were very large, and almost no genotype-environment interaction was present for girth growth. High genotype-environment interaction was present for rubber yield with genetic and phenotypic correlations across the sites, ranging from 0.64 to 0.92 (genetic) and 0.63 to 0.89 (phenotypic). Total number of latex vessels rings had a high heritability, ranging from 20.0% to 64.0% in the sites E and B, respectively.

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Moreno, Rogério Manoel Biagi, Mariselma Ferreira, Paulo de Souza Gonçalves e Luiz Henrique Capparelli Mattoso. "Technological properties of latex and natural rubber of Hevea brasiliensis clones". Scientia Agricola 62, n. 2 (aprile 2005): 122–26. http://dx.doi.org/10.1590/s0103-90162005000200005.

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Rubber industry has increased the requirements for quality and uniformity of natural rubber produced in Brazil. Technological properties of latex and natural rubber of clones GT 1, PB 235, IAN 873 and RRIM 600 [Hevea brasiliensis (Willd. Former Adr. de Juss.) Muell.- Arg] were evaluated by standard methods of the dry rubber content (DRC%), percentage of nitrogen (N%) and percentage of ashes (ASH%) in two consecutive years; data were correlated with temperature and precipitation. Properties of latex and natural rubber varied (P < 0.01) as a function of clone type and among tappings. DRC decreased in the beginning of the dry season (May to June) and N% and ASH% increased in the same period. April to June was a critical period, when N% was above 0.60%, out of standards established by the technical standard ABNT/NBR in Brazil. Clone RRIM 600 was less susceptible to climatic variations.

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Hernandez-Tenorio, Fabian, Héctor Arroyave-Miranda, Alejandra M. Miranda, Sandra M. González, Carlos A. Rodríguez e Alex A. Sáez. "Improving Deproteinization in Colombian Latex from Hevea brasiliensis: A Bibliometric Approximation". Polymers 14, n. 19 (10 ottobre 2022): 4248. http://dx.doi.org/10.3390/polym14194248.

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Natural Rubber Field Latex (NRFL) allergens restrict its use in some markets due to health-threatening allergic reactions. These molecules are proteins that are related to asymptomatic sensitization and hypersensitivity mediated by immunoglobulin E (IgE). Although NRFL allergens have been investigated since the 1980s, there are still gaps in knowledge regarding the development of deproteinized natural rubber (DPNR). Therefore, in this study, the deproteinization of NRFL from the lower basin of the Cauca River, Antioquia-Colombia was evaluated using eight systems. The highest removal value was 84.4% and was obtained from the treatment containing SDS (Sodium dodecyl sulfate), Urea, and Ethanol. It was also possible to determine that at high concentrations of SDS, removal percentages higher than 70% are reached. On the other hand, all deproteinizing systems decreased NRFL Zeta potentials without self-coagulation, suggesting enhanced colloidal stability in DPNR latex. On the other hand, the bibliometric analysis presented technological advances in DPRN through different parameters and bibliometric networks. The analysis presented makes an important contribution from the bibliometric approach that could be positive for the development of research on DPNR.

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Lee, Siang Yin, Kok Lang Mok e Md Yatim Amir Hashim. "RRIM clonal characterisation of Hevea brasiliensis lattices for latex product applications". Journal of Rubber Research 24, n. 5 (dicembre 2021): 829–45. http://dx.doi.org/10.1007/s42464-021-00142-3.

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Wagner, Stefan, e Heimo Breiteneder. "Hevea brasiliensis Latex Allergens: Current Panel and Clinical Relevance". International Archives of Allergy and Immunology 136, n. 1 (2005): 90–97. http://dx.doi.org/10.1159/000082938.

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Chow, K. S., K. L. Wan, Mohd N. M. Isa, A. Bahari, S. H. Tan, K. Harikrishna e H. Y. Yeang. "Insights into rubber biosynthesis from transcriptome analysis of Hevea brasiliensis latex". Journal of Experimental Botany 58, n. 10 (7 giugno 2007): 2429–40. http://dx.doi.org/10.1093/jxb/erm093.

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Raj, Shammi, Gitali Das, Jacob Pothen e Sushil Kumar Dey. "Relationship between latex yield of Hevea brasiliensis and antecedent environmental parameters". International Journal of Biometeorology 49, n. 3 (28 luglio 2004): 189–96. http://dx.doi.org/10.1007/s00484-004-0222-6.

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41

She, Fenghua, Deming Zhu, Lingxue Kong, Jin Wang, Feng An e Weifu Lin. "Ultrasound-assisted tapping of latex from Para rubber tree Hevea brasiliensis". Industrial Crops and Products 50 (ottobre 2013): 803–8. http://dx.doi.org/10.1016/j.indcrop.2013.08.065.

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42

Olivier, Celso Eduardo, Daiana G. Pinto, Ana P. M. Teixeira, Jhéssica L. S. Santana, Raquel A. P. G. Santos e Regiane P. S. Lima. "Contribution of the Leukocyte Adherence Inhibition Test to the Evaluation of Cellular Immunoreactivity against Latex Extracts for Non—IgE-Mediated Latex-Fruit-Pollen Syndrome in Allergic Candidates to Exclusion Diets and Allergic Desensitization". European Journal of Clinical Medicine 3, n. 1 (7 gennaio 2022): 11–17. http://dx.doi.org/10.24018/clinicmed.2022.3.1.160.

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Background: Due to the lack of standardized laboratory procedures able to demonstrate specific non—IgE-mediated immune responses against latex allergens, these conditions are diagnosed mostly by clinical criteria based on empiric exclusion prescriptions monitored by in vivo challenge tests. Objective: To evaluate the opportunity of an ex vivo challenge immunoassay, the Leukocyte Adherence Inhibition (LAI) Test (LAIT), to discriminate non—IgE-mediated latex-specific immunoreactivity. Methods: Ex vivo challenge tests performed with Hevea Brasiliense’s latex extract, monitored by LAIT, were assayed in an asymptomatic control group and a group of patients with diverse respiratory and cutaneous non—IgE-mediated allergic conditions, clinically diagnosed by a certified allergologist. Results: The mean LAI of the control group was 8.3%. The mean LAI of the complete patients’ group was 41.1%. The non-parametric Wilcoxon-Mann-Whitney U (WMWU) test comparing the control group with the whole patient’s group showed significance with a p-value < 0.00001. The WMWU test comparing the control group with each other patient’s group showed significance with a p-value < α = 0.05 for all comparisons. The WMWU test comparing the patients’ groups between each other did not show any significant p-value. Conclusion: Several patients from the diverse non—IgE-mediated allergic phenotypes presented variable immunoreactivity against the latex extract, as demonstrated by the LAIT, which proved to be an easy, quick, and inexpensive ex vivo immunoassay with the potential to predict individual immunoreactivity against Hevea brasiliensis latex allergens in real-world patients with non—IgE-mediated allergies.

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Florence Folaranmi Bolaji e Dr. Ranjita Mohanty. "Production of Biodiesel from Rubber Seed (Hevea Brasiliensis)". International Research Journal on Advanced Engineering and Management (IRJAEM) 2, n. 08 (13 agosto 2024): 2521–25. http://dx.doi.org/10.47392/irjaem.2024.0364.

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In light of the decline of resources that are not renewable and their negative effects on the environment, this article emphasizes the significance of sustainable energy sources. As practical substitutes, renewable energy sources including biomass, geothermal, hydroelectricity, solar, tidal waves, and wind are suggested. Biodiesel manufacturing from vegetable oils obtained from biomass is a viable alternative, and these oils are thought to be an affordable and easily available source of renewable energy. But using edible oils to produce biodiesel puts the food and pharmaceutical businesses in rivalry, which results in a food-fuel problem. Vegetable oils that are not edible, such those from the tree that produces rubber (Hevea Brasiliensis), provide a more environmentally friendly way to produce biodiesel. The seeds of rubber trees are underused and are already planted for the manufacture of latex. With the use of a leftover rubber kernel shell catalyst used, this study looks at the process of conversion of the oil from rubber seeds to biodiesel and shows encouraging findings. It is anticipated that using non-edible oils in the manufacturing of biodiesel will lower prices and make it more competitive with petro-diesel.

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Ferreira, Mariselma, Rogério M. B. Moreno, Paulo S. Gonçalves e Luiz H. C. Mattoso. "Evaluation of Natural Rubber from Clones of Hevea Brasiliensis". Rubber Chemistry and Technology 75, n. 1 (1 marzo 2002): 171–77. http://dx.doi.org/10.5254/1.3547668.

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Abstract The latex and natural rubber from rubber trees [Hevea brasiliensis (Willd. exAdr. de Juss.) Muell. Arg.] from clones (RRIM 600, IAN 873, GT 1 and PB 252) recommended to the state of São Paulo, Brazil, were studied in three different tapping systems. The parameters studied were dry rubber content (DRC), percentages of ash and of nitrogen, Wallace Plasticity (P0) and Mooney Viscosity (VR). The rubber properties vary considerably as a function of clone type, tapping method and season of the year. DRC tends to decrease in the beginning of the dry, cold season (May and June), whereas both nitrogen % and ash % increase in the same period. A good linear correlation was obtained for P0 and VR. The highest P0 and VR were obtained for RRIM 600.

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Chiang, Cheng Ching K., Balaka Barkakaty, Judit E. Puskas, Wenshuang Xie, Katrina Cornish, Federic Peruch e Alain Deffieux. "UNRAVELING THE MYSTERY OF NATURAL RUBBER BIOSYNTHESIS. PART II: COMPOSITION AND GROWTH OF IN VITRO NATURAL RUBBER USING HIGH-RESOLUTION SIZE EXCLUSION CHROMATOGRAPHY". Rubber Chemistry and Technology 87, n. 3 (1 settembre 2014): 451–58. http://dx.doi.org/10.5254/rct.14.87913.

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ABSTRACT The superior properties of natural rubber (cis-1,4-polyisoprene [NR]) are a function of its structure and composition, properties that still remain a mystery and that are irreplaceable by any synthetic rubber. NR from guayule (Parthenium argentatum) has been gaining special interest for its hypoallergenic properties while maintaining superior mechanical properties that are commonly associated with the Brazilian rubber tree (Hevea brasiliensis), the most common source of NR. Techniques exist to isolate washed rubber particles (WRPs) that contain enzymatically active rubber transferase, to study NR biosynthesis, and previous work on the in vitro NR growth in Hevea has demonstrated the presence of around 50 wt% of a low molecular weight ([MW], Mn <10 000 g/mol) fraction. Structural and compositional analyses of this low MW fraction in Hevea are challenging due to the high protein content. We discuss the analysis and composition of guayule latex and WRPs using high-resolution Size Exclusion Chromatography. We also discuss the composition of the soluble fraction of inactive guayule latex using matrix-assisted laser desorption ionization/time of flight mass spectrometry.

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Kusumarn Noipha, Piyanuch Suwannarat, Supattra Prom-in e Titpawan Nakpheng. "Phytochemical, Antioxidant and Antimicrobial Activities of Hevea brasiliensis Leaves Extract". HAYATI Journal of Biosciences 31, n. 2 (13 novembre 2023): 241–47. http://dx.doi.org/10.4308/hjb.31.2.241-247.

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Belonging to the Euphorbiaceae family, the Para rubber tree is formally referred to as Hevea brasiliensis in scientific terms. It is commonly known as an important economic commodity in Thailand because the natural rubber primarily originates from the milky latex obtained from the tree. However, the available research on the phytochemicals found in different parts of the rubber tree and their biological effects is quite restricted. This study aimed to determine the phytochemical constituents, antioxidant and antibacterial activity studies on the crude dry leaf extracts of H. brasiliensis. The results indicated the presence of alkaloids, anthraquinones, cardiac glycosides, coumarin, flavonoids, saponin, steroids, tannins, and terpenoids. The total phenolic content was 63.95±4.31 mgGAE/g in the ethanolic leaf extract. The ethanolic extract displayed notable effectiveness in scavenging free radicals (71.2±0.17%) at 500 μg/ml concentration and antioxidant capacity (the lowest IC50 value 42.57±0.91 μg/ml). The ethanol extract of the leaf of H. brasiliensis showed inhibition zone on all of the selected bacteria (gram-positive; Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, and gram-negative; Escherichia coli, Pseudomonas aeruginosa) at 200 mg/ml. In conclusion, the dried leaves of H. brasiliensis compose phytochemicals that exhibit antioxidant and antibacterial activities and possesses the potential to act as a reservoir of plant-derived antibiotics and natural antioxidants.

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CARR, M. K. V. "THE WATER RELATIONS OF RUBBER (HEVEA BRASILIENSIS): A REVIEW". Experimental Agriculture 48, n. 2 (12 ottobre 2011): 176–93. http://dx.doi.org/10.1017/s0014479711000901.

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SUMMARYThe results of research done on water relations of rubber are collated and summarised in an attempt to link fundamental studies on crop physiology to crop management practices. Background information is given on the centres of origin (Amazon Basin) and production of rubber (humid tropics; south-east Asia), but the crop is now being grown in drier regions. The effects of water stress on the development processes of the crop are summarised, followed by reviews of its water relations, water requirements and water productivity. The majority of the recent research published in the international literature has been conducted in south-east Asia. The rubber tree has a single straight trunk, the growth of which is restricted by ‘tapping’ for latex. Increase in stem height is discontinuous, a period of elongation being followed by a ‘rest’ period during which emergence of leaves takes place. Leaves are produced in tiers separated by lengths of bare stem. Trees older than three to four years shed senescent leaves (a process known as ‘wintering’). ‘Wintering’ is induced by dry, or less wet, weather; trees may remain (nearly) leafless for up to four weeks. The more pronounced the dry season the shorter the period of defoliation. Re-foliation begins before the rains start. The supply of latex is dependent on the pressure potential in the latex vessels, whereas the rate of flow is negatively correlated with the saturation deficit of the air. Radial growth of the stem declines in tapped trees relative to untapped trees within two weeks of the start of tapping. Roots can extend in depth to more than 4 m and laterally more than 9 m from the trunk. The majority of roots are found within 0.3 m of the soil surface. Root elongation is depressed during leaf growth, while root branching is enhanced. Stomata are only found on the lower surface of the leaf, at densities from 280 to 700 mm−2. The xylem vessels of rubber trees under drought stress are vulnerable to cavitation, particularly in the leaf petiole. By closing, the stomata play an essential role in limiting cavitation. Clones differ in their susceptibility to cavitation, which occurs at xylem water potentials in the range of −1.8 to −2.0 MPa. Clone RRII 105 is capable of maintaining higher leaf water potentials than other clones because of stomatal closure, supporting its reputation for drought tolerance. Clones differ in their photosynthetic rates. Light inhibition of photosynthesis can occur, particularly in young plants, when shade can be beneficial. Girth measurements have been used to identify drought-tolerant clones. Very little research on the water requirements of rubber has been reported, and it is difficult to judge the validity of the assumptions made in some of the methodologies described. The actual evapotranspiration rates reported are generally lower than might be expected for a tree crop growing in the tropics (<3 mm d−1). Virtually no research on the yield responses to water has been reported and, with the crop now being grown in drier regions, this is surprising. In these areas, irrigation can reduce the immaturity period from more than 10 years to six years. The important role that rubber plays in the livelihoods of smallholders, and in the integrated farming systems practised in south-east Asia, is summarized.

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Wijaya, Andi, Arief Rachmawan e Mochlisin Andriyanto. "Total Solid Content and Compound Properties from Different Collection Time of Hevea brasiliensis Latex". Acta Technologica Agriculturae 22, n. 4 (1 dicembre 2019): 104–8. http://dx.doi.org/10.2478/ata-2019-0019.

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Abstract This study compared the total solid content and compound properties of Hevea rubber latex produced from material collected during different periods. Samples were collected from five trees, with the collection replicated three times with tapping task as replication. Observed parameters included total solid content, vulcanization characteristics, technical and physical properties. The results exhibited that the longer latex flowed, the more total solid content tended to decrease. Results indicate that compound of latex collected 20 minutes (C20), 60 minutes (C60), and 300 minutes (C300) after tapping qualified for SIR 20. Other parameters did not show a significant difference among the three tested compounds. Considering the products requiring high dry rubber content, it is suggested not to blend the late collection with main collected latex.

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He, Lixia, Yang Yang, Junjun Ma, Boxuan Yuan, Fengyan Fang, Juanying Wang, Mei Wang et al. "Transcriptomic and Proteomic Integration Reveals Key Tapping-Responsive Factors for Natural Rubber Biosynthesis in the Rubber Tree Hevea brasiliensis". Forests 15, n. 10 (16 ottobre 2024): 1807. http://dx.doi.org/10.3390/f15101807.

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Natural rubber is a crucial industrial material, and it is primarily harvested from the latex of the rubber tree Hevea brasiliensis by tapping the tree trunk. During the regular tapping process, mechanical damage seriously affects latex reproduction and rubber yield, but the molecular mechanisms on tapping stimulation remain unclear. In this study, we firstly determined the changed physiological markers on latex regeneration, overall latex yield, and latex flow time during the tapping process. Then, we combined proteomics and transcriptomics analyses of latex during tapping and identified 3940 differentially expressed genes (DEGs) and 193 differentially expressed proteins (DEPs). Among them, 773 DEGs and 120 DEPs displayed a persistent upregulation trend upon tapping. It is interesting that, in the detected transcription factors, basic helix-loop-helix (bHLH) family members occupied the highest proportion among all DEGs, and this trend was similarly observed in DEPs. Notably, 48 genes and 34 proteins related to natural rubber biosynthesis were identified, and most members of small rubber particle protein (SRPP) and rubber elongation factor (REF) showed a positive response to tapping stimulation. Among them, SRPP6 and REF5 showed significant and sustained upregulation at the gene and protein levels following tapping, indicating their pivotal roles for post-tapping rubber biosynthesis. Our results deepen the comprehension of the regulation mechanism underlying tapping and provide candidate genes and proteins for improving latex production in the Hevea rubber tree in future.

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Qiu, Yi-Min, Jing Guo, Wei-Zeng Jiang, Jia-Hui Ding, Ru-Feng Song, Jian-Long Zhang, Xi Huang e Hong-Mei Yuan. "HbBIN2 Functions in Plant Cold Stress Resistance through Modulation of HbICE1 Transcriptional Activity and ROS Homeostasis in Hevea brasiliensis". International Journal of Molecular Sciences 24, n. 21 (30 ottobre 2023): 15778. http://dx.doi.org/10.3390/ijms242115778.

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Cold stress poses significant limitations on the growth, latex yield, and ecological distribution of rubber trees (Hevea brasiliensis). The GSK3-like kinase plays a significant role in helping plants adapt to different biotic and abiotic stresses. However, the functions of GSK3-like kinase BR-INSENSITIVE 2 (BIN2) in Hevea brasiliensis remain elusive. Here, we identified HbBIN2s of Hevea brasiliensis and deciphered their roles in cold stress resistance. The transcript levels of HbBIN2s are upregulated by cold stress. In addition, HbBIN2s are present in both the nucleus and cytoplasm and have the ability to interact with the INDUCER OF CBF EXPRESSION1(HbICE1) transcription factor, a central component in cold signaling. HbBIN2 overexpression in Arabidopsis displays decreased tolerance to chilling stress with a lower survival rate and proline content but a higher level of electrolyte leakage (EL) and malondialdehyde (MDA) than wild type under cold stress. Meanwhile, HbBIN2 transgenic Arabidopsis treated with cold stress exhibits a significant increase in the accumulation of reactive oxygen species (ROS) and a decrease in the activity of antioxidant enzymes. Further investigation reveals that HbBIN2 inhibits the transcriptional activity of HbICE1, thereby attenuating the expression of C-REPEAT BINDING FACTOR (HbCBF1). Consistent with this, overexpression of HbBIN2 represses the expression of CBF pathway cold-regulated genes under cold stress. In conclusion, our findings indicate that HbBIN2 functions as a suppressor of cold stress resistance by modulating HbICE1 transcriptional activity and ROS homeostasis.

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