Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 793
Filtrar
1.
PLoS One ; 19(3): e0297284, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38512907

RESUMO

Addressing the profound impact of Tapping Panel Dryness (TPD) on yield and quality in the global rubber industry, this study introduces a cutting-edge Otsu threshold segmentation technique, enhanced by Dung Beetle Optimization (DBO-Otsu). This innovative approach optimizes the segmentation threshold combination by accelerating convergence and diversifying search methodologies. Following initial segmentation, TPD severity levels are meticulously assessed using morphological characteristics, enabling precise determination of optimal thresholds for final segmentation. The efficacy of DBO-Otsu is rigorously evaluated against mainstream benchmarks like Peak Signal-to-Noise Ratio (PSNR), Structural Similarity Index (SSIM), and Feature Similarity Index (FSIM), and compared with six contemporary swarm intelligence algorithms. The findings reveal that DBO-Otsu substantially surpasses its counterparts in image segmentation quality and processing speed. Further empirical analysis on a dataset comprising TPD cases from level 1 to 5 underscores the algorithm's practical utility, achieving an impressive 80% accuracy in severity level identification and underscoring its potential for TPD image segmentation and recognition tasks.


Assuntos
Hevea , Borracha , Algoritmos , Processamento de Imagem Assistida por Computador/métodos
2.
Int J Mol Sci ; 25(5)2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38474173

RESUMO

Transgenic technology is a crucial tool for gene functional analysis and targeted genetic modification in the para rubber tree (Hevea brasiliensis). However, low efficiency of plant regeneration via somatic embryogenesis remains a bottleneck of successful genetic transformation in H. brasiliensis. Enhancing expression of GROWTH-REGULATING FACTOR 4 (GRF4)-GRF-INTERACTING FACTOR 1 (GIF1) has been reported to significantly improve shoot and embryo regeneration in multiple crops. Here, we identified endogenous HbGRF4 and HbGIF1 from the rubber clone Reyan7-33-97, the expressions of which dramatically increased along with somatic embryo (SE) production. Intriguingly, overexpression of HbGRF4 or HbGRF4-HbGIF1 markedly enhanced the efficiency of embryogenesis in two H. brasiliensis callus lines with contrasting rates of SE production. Transcriptional profiling revealed that the genes involved in jasmonic acid response were up-regulated, whereas those in ethylene biosynthesis and response as well as the S-adenosylmethionine-dependent methyltransferase activity were down-regulated in HbGRF4- and HbGRF4-HbGIF1-overexpressing H. brasiliensis embryos. These findings open up a new avenue for improving SE production in rubber tree, and help to unravel the underlying mechanisms of HbGRF4-enhanced somatic embryogenesis.


Assuntos
Hevea , Hevea/genética , Borracha/metabolismo , Látex , Regulação da Expressão Gênica de Plantas
3.
Plant Sci ; 341: 112011, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38311252

RESUMO

Currently, one of the most serious threats to rubber tree is the tapping panel dryness (TPD) that greatly restricts natural rubber production. Over-tapping or excessive ethephon stimulation is regarded as the main cause of TPD occurrence. Although extensive studies have been carried out, the molecular mechanism underlying TPD remains puzzled. An attempt was made to compare the levels of endogenous hormones and the profiles of transcriptome and proteome between healthy and TPD trees. Results showed that most of endogenous hormones such as jasmonic acid (JA), 1-aminocyclopropanecarboxylic acid (ACC), indole-3-acetic acid (IAA), trans-zeatin (tZ) and salicylic acid (SA) in the barks were significantly altered in TPD-affected rubber trees. Accordingly, multiple hormone-mediated signaling pathways were changed. In total, 731 differentially expressed genes (DEGs) and 671 differentially expressed proteins (DEPs) were identified, of which 80 DEGs were identified as putative transcription factors (TFs). Further analysis revealed that 12 DEGs and five DEPs regulated plant hormone synthesis, and that 16 DEGs and six DEPs were involved in plant hormone signal transduction pathway. Nine DEGs and four DEPs participated in rubber biosynthesis and most DEGs and all the four DEPs were repressed in TPD trees. All these results highlight the potential roles of endogenous hormones, signaling pathways mediated by these hormones and rubber biosynthesis pathway in the defense response of rubber trees to TPD. The present study extends our understanding of the nature and mechanism underlying TPD and provides some candidate genes and proteins related to TPD for further research in the future.


Assuntos
Hevea , Hevea/genética , Hevea/metabolismo , Borracha/metabolismo , Transcriptoma , Látex/metabolismo , Proteoma/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Transdução de Sinais , Hormônios/metabolismo , Regulação da Expressão Gênica de Plantas
4.
Tree Physiol ; 44(3)2024 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-38349811

RESUMO

Land surface temperature is predicted to increase by 0.2 °C per decade due to climate change, although with considerable regional variability, and heatwaves are predicted to increase markedly in the future. These changes will affect where crops can be grown in the future. Understanding the thermal limits of plant physiological functioning and how flexible such limits are is thus important. Here, we report on the measurements of a core foliar thermotolerance trait, T50, defined as the temperature at which the maximum quantum yield (Fv/Fm) of photosystem II declines by 50%, across nine different Malaysian Hevea brasiliensis clones. We explore the relative importance of interclonal versus intraclonal variation in T50 as well as its association with leaf and hydraulic traits. We find very low variation in T50 within individual clones (mean intraclonal coefficient of variation (CoV) of 1.26%) and little variation across clones (interclonal CoV of 2.1%). The interclonal variation in T50 was lower than for all other functional traits considered. The T50 was negatively related to leaf mass per area and leaf dry matter content, but it was not related to hydraulic traits such as embolism resistance (P50) or hydraulic safety margins (HSM50). The range of T50 observed (42.9-46.2 °C) is well above the current maximum air temperatures Tmax,obs (T50 - Tmax,obs >5.8 °C), suggesting that H. brasiliensis is likely thermally safe in this south-east Asian region of Malaysia.


Assuntos
Hevea , Termotolerância , Hevea/fisiologia , Folhas de Planta/fisiologia , Temperatura , Fenótipo
5.
Sci Rep ; 14(1): 1072, 2024 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-38212354

RESUMO

Pathogenesis-related 10 (PR-10) is a group of small intracellular proteins that is one of 17 subclasses of pathogenesis-related proteins in plants. The PR-10 proteins have been studied extensively and are well-recognized for their contribution to host defense against phytopathogens in several plant species. Interestingly, the accumulation of PR-10 proteins in the rubber tree, one of the most economically important crops worldwide, after being infected by pathogenic organisms has only recently been reported. In this study, the homologous proteins of the PR-10 family were systemically identified from the recently available rubber tree genomes in the NCBI database. The sequence compositions, structural characteristics, protein physical properties, and phylogenetic relationships of identified PR-10 proteins in rubber trees support their classification into subgroups, which mainly consist of Pru ar 1-like major allergens and major latex-like (MLP) proteins. The rubber tree PR10-encoding genes were majorly clustered on chromosome 15. The potential roles of rubber tree PR-10 proteins are discussed based on previous reports. The homologous proteins in the PR-10 family were identified in the recent genomes of rubber trees and were shown to be crucial in host responses to biotic challenges. The genome-wide identification conducted here will accelerate the future study of rubber tree PR-10 proteins. A better understanding of these defense-related proteins may contribute to alternative ways of developing rubber tree clones with desirable traits in the future.


Assuntos
Hevea , Hevea/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Látex/metabolismo , Genoma de Planta , Regulação da Expressão Gênica de Plantas , Borracha/metabolismo
6.
Biomater Adv ; 157: 213754, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38211507

RESUMO

Chronic wounds pose significant health concerns. Current treatment options include natural compounds like natural rubber latex (NRL) from Hevea brasiliensis. NRL, particularly the F1 protein fraction, has demonstrated bioactivity, biocompatibility, and angiogenic effects. So far, there is no study comparing F1 protein with total NRL serum, and the necessity of downstream processing remains unknown. Here, we evaluated the angiogenic potential of F1 protein compared to total NRL serum and the need for downstream processing. For that, ion exchange chromatography (DEAE-Sepharose), antioxidant activity, physicochemical characterization, cell culture in McCoy fibroblasts, and wound healing in Balb-C mice were performed. Also, the evaluation of histology and collagen content and the levels of inflammatory mediators were quantified. McCoy fibroblast cell assay showed that F1 protein (0.01 %) and total NRL serum (0.01 %) significantly increased cell proliferation by 47.1 ± 11.3 % and 25.5 ± 2.5 %, respectively. However, the AA of F1 protein (78.9 ± 0.8 %) did not show a significant difference compared to NRL serum (77.0 ± 1.1 %). F1 protein and NRL serum were more effective in wound management in rodents. Histopathological analysis confirmed accelerated healing and advanced tissue repair. Similarly, the F1 protein (0.01 %) increased collagen, showing that this fraction can stimulate the synthesis of collagen by fibroblastic cells. Regarding cytokines production (IL-10, TNF-α, IFN-γ), F1 protein and NRL serum did not exert an impact on the synthesis of these cytokines. Furthermore, we did not observe statistically significant changes in dosages of enzymes (MPO and EPO) among the groups. Nevertheless, Nitric Oxide dosage was reduced drastically when the F1 protein (0.01 %) protein was applied topically. These findings contribute to the understanding of F1 protein and NRL serum properties and provide insights into cost-effectiveness and practical applications in medicine and biotechnology. Therefore, further research is needed to assess the economic feasibility of downstream processing for NRL-based herbal medicine derived from Hevea brasiliensis.


Assuntos
Hevea , Borracha , Animais , Camundongos , Látex , Hevea/química , Cicatrização , Colágeno , Citocinas
7.
Plant Reprod ; 37(1): 47-56, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37758937

RESUMO

KEY MESSAGE: Unreduced megagametophytes via second-division restitution were confirmed through heterozygosity analysis, and four candidate physical centromeres of rubber were located for the first time. The evaluation of maternal heterozygosity restitution (MHR) is vital in identifying the mechanism of 2n gametogenesis and assessing the utilization value of 2n gametes. In this study, three full-sib triploid populations were employed to evaluate the MHR of 2n female gametes of rubber tree clone GT1 and to confirm their genetic derivation. The 2n female gametes of GT1 were derived from second-division restitution (SDR) and transmitted more than half of the parental heterozygosity. In addition, low recombination frequency markers were developed, and four candidate physical centromeres of rubber tree were located for the first time. The confirmation that 2n female gametes of rubber tree clone GT1 are derived from SDR provides insights into the molecular mechanisms of 2n gametogenesis. In addition, the identified centromere location will aid in the development of centromeric markers for the rapid identification of the 2n gametogenesis mechanism.


Assuntos
Hevea , Triploidia , Hevea/genética , Diploide , Células Germinativas , Centrômero/genética
8.
Plant Dis ; 108(1): 62-70, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37467126

RESUMO

In order to manage agricultural pathogens, it is crucial to understand the population structure underlying epidemics. Rubber tree powdery mildew, caused by Erysiphe quercicola, is a serious threat to rubber plantations worldwide, especially in subtropical environments including all rubber tree-growing regions in China. However, the population structure of the pathogen is uncertain. In this study, 16 polymorphic microsatellite markers were used to genotype powdery mildew samples from the main rubber tree-growing regions including Yunnan (YN), Hainan (HN), western Guangdong (WG), and eastern Guangdong (EG). YN had higher genotypic diversity (Simpson's indices), genotypic evenness, Nei's gene diversity, allelic richness, and private allelic richness than the other regions. Cluster analysis, discriminant analysis of principal components, pairwise divergence, and shared multilocus genotype analyses all showed that YN differed significantly from the other regions. The genetic differentiation was small among the other three regions (HN, WG, and EG). Analysis of molecular variance indicated that the variability among regions accounted for 22.37% of the total variability. Genetic differentiation was significantly positively correlated (Rxy = 0.772, P = 0.001) with geographic distance. Linkage equilibrium analysis suggested possible occurrence of sexual recombination although asexual reproduction predominates in E. quercicola. The results suggested that although significant genetic differentiation of E. quercicola occurred between YN and the other regions, pathogen populations from the other three regions lacked genetic differentiation.


Assuntos
Ascomicetos , Erysiphe , Hevea , Hevea/genética , Doenças das Plantas , China , Ascomicetos/genética , Genética Populacional
9.
Sci Total Environ ; 913: 169335, 2024 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-38103613

RESUMO

Soil erosion on agricultural land is a major threat for food and raw materials production. It has become a major concern in rubber (Hevea brasiliensis) plantations introduced on sloping ground. Alternative agroecological crop management practices must be investigated. One aim of our study was to assess the ability of logging residues (i.e., trunks, branches, leaves and stumps of a clearcut plantation) and of legume cover (Pueraria phaseoloides) to mitigate N, P and K losses through runoff and soil detachment in a young rubber plantation. The other aim was to investigate the relationships of these nutrient losses with soil structure and soil macrofauna diversity. Runoff and soil loss were monitored for 3 years using 1-m2 plots under different practices as regards the management of logging residues and the use or not of a legume. The monitoring started when rubber trees were one-year-old. The planting row, where soil was bare, was the hotspot of soil erosion, with an average runoff of 832 mm y-1 and soil loss of 3.2 kg m-2 y-1. Sowing a legume in the inter-row reduced runoff and soil loss by 88 % and 98 % respectively, compared to bare soil. Spreading logging residues as well as growing a legume cover almost eliminated runoff and soil detachment (19 mm y-1 and 4 g m-2 y-1 respectively). Nutrient losses were negligible as long as the soil surface was covered by a legume crop, with or without logging residues. Total N loss from soil detachment ranged from 0.02 to 0.2 g m-2 y-1, for example. Spreading logging residues in the inter-rows significantly improved soil structure and soil macrofauna diversity compared to bare soil. Nutrient losses from runoff and soil detachment were negatively correlated with improved soil structure and soil macrofauna diversity. We recommend investigating alternative ways to manage planting rows.


Assuntos
Fabaceae , Hevea , Solo/química , Borracha , Agricultura , Verduras
10.
Int J Mol Sci ; 24(21)2023 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-37958762

RESUMO

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.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Hevea , Hevea/genética , Hevea/metabolismo , Resposta ao Choque Frio/genética , Espécies Reativas de Oxigênio/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Homeostase , Proteínas Quinases/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo
11.
Rev Alerg Mex ; 70(4): 146-158, 2023 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-37933924

RESUMO

Abstract: La planta Hevea brasiliensis se utiliza ampliamente en la industria como fuente de extracción de caucho, un elemento empleado en diversas áreas comerciales y médicas. Los estudios inmunológicos de esta especie indican que es una fuente alergénica importante, que puede provocar sensibilización y alergia. Se han identificado diferentes componentes alergénicos de esta planta, con diversas propiedades inmunitarias y bioquímicas, y estudiado más de diez tipos diferentes de alérgenos, cada uno con distinta capacidad de inducir síntomas alérgicos. En esta revisión informamos los avances actuales en el estudio de Hevea brasiliensis.


Resumen: Hevea brasiliensis, a plant species used extensively for rubber extraction, is a common allergenic source that can cause sensitization and allergic reactions. Recent immunological studies have characterized various allergenic components of Hevea brasiliensis that possess diverse immune and biochemical properties. Over ten types of allergens have been identified, each with varying capacities to induce allergic symptoms. This review presents the current advances in the study of this allergenic source.


Assuntos
Hevea , Humanos , Estudos Retrospectivos
12.
Braz J Biol ; 83: e274032, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37937626

RESUMO

The rubber tree (Hevea brasiliensis (Willd. ex A.Juss.) Müll.Arg.), a native Amazonian species, is responsible for more than 50 thousand products and stands out as the world's main source of natural rubber. Commercial production is carried out by grafting, however, the technique has gaps in terms of time and quality for seedling production. Vegetative production via cuttings is an alternative, however, the species is difficult to root. Thus, the study tested the rooting induction, through a chemical method, with the hormonal regulator indolbutyric acid (IBA) of 5000 ppm, and a mechanical method, with the strangulation of stems, and the interaction between the methods, to analyze the survival and sprouting of rubber tree (Hevea brasiliensis) cuttings, as well as verifying the efficiency of breaking the sclerenchyma ring by strangulation. A randomized block design was used, with four treatments (control, with strangulation, with IBA, strangulation x IBA) distributed in six blocks with 36 cuttings. Data were submitted to ANOVA test and Tukey's post-test (p>0.05). The results obtained 12.5% of live cuttings, without rooting, during 68 days, being the combination of strangulation and IBA with greater survival and sprouting. No breakage of the sclerenchyma ring was observed by histological analysis. The data indicate strategic gains in combining chemical and mechanical techniques for species of difficult rooting in vegetative propagation, however, the test was not enough to affirm an answer in relation to each technique, the deepening of the technique on the behavior of the species remains the biggest challenge.


Assuntos
Hevea , Reprodução
13.
Plant Physiol Biochem ; 205: 108156, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37979576

RESUMO

Tapping panel dryness (TPD) results in a severe reduction in latex yield in Hevea brasiliensis. However, the molecular regulatory mechanisms of TPD occurrence are still largely unclear. In this study, whole-transcriptome sequencing was carried out on latex from TPD and healthy trees. In total, 7078 long noncoding RNAs (lncRNAs), 3077 circular RNAs (circRNAs), 4956 miRNAs, and 25041 mRNAs were identified in latex, among which 435 lncRNAs, 68 circRNAs, 320 miRNAs, and 1574 mRNAs were differentially expressed in the latex of TPD trees. GO and KEGG analyses indicated that plant hormone signal transduction, MAPK signaling pathway, and ubiquitin-mediated proteolysis were the key pathways associated with TPD onset. Phytohormone profiling revealed significant changes in the contents of 28 hormonal compounds, among which ACC, ABA, IAA, GA, and JA contents were increased, while SA content was reduced in TPD latex, suggesting that hormone homeostasis is disrupted in TPD trees. Furthermore, we constructed a TPD-related competitive endogenous RNA (ceRNA) regulatory network of lncRNA/circRNA-miRNA-mRNA with 561 edges and 434 nodes (188 lncRNAs, 5 circRNAs, 191 miRNAs, and 50 mRNAs) and identified two hub lncRNAs (MSTRG.11908.1 and MSTRG.8791.1) and four hub miRNAs (hbr-miR156, miR156-x, miRf10477-y, and novel-m0452-3p). Notably, the lncRNA-miR156/157-SPL module containing three hubs probably plays a crucial role in TPD onset. The expression of network hubs and the lncRNA-miR156/157-SPL module were further validated by qRT-PCR. Our results reveal the TPD-associated ceRNA regulatory network of lncRNA/circRNA-miRNA-mRNA in latex and lay a foundation for further investigation of molecular regulatory mechanisms for TPD onset in H. brasiliensis.


Assuntos
Hevea , MicroRNAs , RNA Longo não Codificante , Látex , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Circular/genética , RNA Circular/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Hevea/genética , Hevea/metabolismo , RNA Longo não Codificante/genética , Reguladores de Crescimento de Plantas/metabolismo , Redes Reguladoras de Genes
14.
Int J Mol Sci ; 24(22)2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-38003251

RESUMO

Plant PP2C genes are crucial for various biological processes. To elucidate the potential functions of these genes in rubber tree (Hevea brasiliensis), we conducted a comprehensive analysis of these genes using bioinformatics methods. The 60 members of the PP2C family in rubber tree were identified and categorized into 13 subfamilies. The PP2C proteins were conserved across different plant species. The results revealed that the HbPP2C genes contained multiple elements responsive to phytohormones and stresses in their promoters, suggesting their involvement in these pathways. Expression analysis indicated that 40 HbPP2C genes exhibited the highest expression levels in branches and the lowest expression in latex. Additionally, the expression of A subfamily members significantly increased in response to abscisic acid, drought, and glyphosate treatments, whereas the expression of A, B, D, and F1 subfamily members notably increased under temperature stress conditions. Furthermore, the expression of A and F1 subfamily members was significantly upregulated upon powdery mildew infection, with the expression of the HbPP2C6 gene displaying a remarkable 33-fold increase. These findings suggest that different HbPP2C subgroups may have distinct roles in the regulation of phytohormones and the response to abiotic and biotic stresses in rubber tree. This study provides a valuable reference for further investigations into the functions of the HbPP2C gene family in rubber tree.


Assuntos
Hevea , Hevea/genética , Hevea/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Reguladores de Crescimento de Plantas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Látex/metabolismo , Estresse Fisiológico/genética , Regulação da Expressão Gênica de Plantas , Filogenia
15.
BMC Plant Biol ; 23(1): 489, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37828441

RESUMO

BACKGROUND: Rubber plant (Hevea brasiliensis) is one of the major sources of latex. Somatic embryogenesis (SE) is a promising alterative to its propagation by grafting and seed. Phytohormones have been shown to influence SE in different plant species. However, limited knowledge is available on the role of phytohormones in SE in Hevea. The anther cultures of two Hevea genotypes (Yunyan 73477-YT and Reken 628-RT) with contrasting SE rate were established and four stages i.e., anthers (h), anther induced callus (y), callus differentiation state (f), and somatic embryos (p) were studied. UPLC-ESI-MS/MS and transcriptome analyses were used to study phytohormone accumulation and related expression changes in biosynthesis and signaling genes. RESULTS: YT showed higher callus induction rate than RT. Of the two genotypes, only YT exhibited successful SE. Auxins, cytokinins (CKs), abscisic acid (ABA), jasmonic acid (JA), salicylic acid (SA), gibberellins (GAs), and ethylene (ETH) were detected in the two genotypes. Indole-3-acetic acid (IAA), CKs, ABA, and ETH had notable differences in the studied stages of the two genotypes. The differentially expressed genes identified in treatment comparisons were majorly enriched in MAPK and phytohormone signaling, biosynthesis of secondary metabolites, and metabolic pathways. The expression changes in IAA, CK, ABA, and ETH biosynthesis and signaling genes confirmed the differential accumulation of respective phytohormones in the two genotypes. CONCLUSION: These results suggest potential roles of phytohormones in SE in Hevea.


Assuntos
Hevea , Reguladores de Crescimento de Plantas , Reguladores de Crescimento de Plantas/metabolismo , Hevea/genética , Hevea/metabolismo , Espectrometria de Massas em Tandem , Perfilação da Expressão Gênica , Ácido Abscísico/metabolismo , Citocininas/metabolismo , Genótipo , Desenvolvimento Embrionário
16.
J Toxicol Environ Health A ; 86(22): 846-858, 2023 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-37671816

RESUMO

It is known that UVB radiation induces several adverse skin alterations starting from simple photoaging to skin cancer. In addition, it was demonstrated that reactive oxygen species (ROS) were found to be related to cancer development and progression. The aim of study was to examine whether male hairless (SKH-1) mice (Mus musculus) that were subchronically exposed to UVB radiation presented with actinic keratosis (AK) and squamous cell carcinoma lesions, and that treatment with latex C-serum cream significantly prevented abnormal skin development. Data demonstrated for the first time the photoprotective activity of latex C-serum extracted from the rubber tree Hevea brasiliensis var. subconcolor Ducke. Latex C-serum prevented the progression of AK to squamous cell carcinoma in SKH-1 mice, indicating that mice topically treated with latex C-serum presented only AK lesions and treatment with the highest concentration (10%) significantly reduced epidermal thickness, suggesting diminished cell proliferation. Latex C-serum protected the skin of mice against oxidative stress damage, increasing catalase (CAT) activity, regenerating glutathione (GSH) levels, lowering thiobarbituric acid-reactive species (TBARS) production and regenerating the total antioxidant capacity (TAC) of the skin. Evidence that UV radiation in skin induced systemic alterations and erythrocytic analysis indicated that latex C-serum increased CAT activity and GSH levels. Taken together these data indicate that latex C-serum plays an important antioxidant and photoprotective role, preventing serious damage to the skin following exposure to UVB radiation.


Assuntos
Carcinoma de Células Escamosas , Hevea , Animais , Camundongos , Antioxidantes , Raios Ultravioleta/efeitos adversos , Látex , Glutationa
17.
Tree Physiol ; 43(12): 2131-2149, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-37707940

RESUMO

The predicted increase of drought intensity in South-East Asia has raised concern about the sustainability of rubber (Hevea brasiliensis Müll. Arg.) cultivation. In order to quantify the degree of phenotypic plasticity in this important tree crop species, we analysed a set of wood and leaf traits related to the hydraulic safety and efficiency in PB260 clones from eight small-holder plantations in Jambi province, Indonesia, representing a gradient in local microclimatic and edaphic conditions. Across plots, branch embolism resistance (P50) ranged from -2.14 to -2.58 MPa. The P50 and P88 values declined, and the hydraulic safety margin increased, with an increase in the mean annual vapour pressure deficit (VPD). Among leaf traits, only the changes in specific leaf area were related to the differences in evaporative demand. These variations of hydraulic trait values were not related to soil moisture levels. We did not find a trade-off between hydraulic safety and efficiency, but vessel density (VD) emerged as a major trait associated with both safety and efficiency. The VD, and not vessel diameter, was closely related to P50 and P88 as well as to specific hydraulic conductivity, the lumen-to-sapwood area ratio and the vessel grouping index. In conclusion, our results demonstrate some degree of phenotypic plasticity in wood traits related to hydraulic safety in this tropical tree species, but this is only in response to the local changes in evaporative demand and not soil moisture. Given that VPD may increasingly limit plant growth in a warmer world, our results provide evidence of hydraulic trait changes in response to a rising evaporative demand.


Assuntos
Hevea , Madeira , Madeira/fisiologia , Borracha , Solo , Folhas de Planta/fisiologia , Árvores/fisiologia , Secas , Água/fisiologia , Xilema/fisiologia
18.
Biochem Biophys Res Commun ; 679: 205-214, 2023 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-37708579

RESUMO

According to the fatty acid and headgroup compositions of the phospholipids (PL) from Hevea brasiliensis latex, three synthetic PL were selected (i.e. POPA: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphate POPC: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine and POPG: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol) to investigate the effect of PL headgroup on the interactions with two major proteins of Hevea latex, i.e. Rubber Elongation Factor (REF1) and Small Rubber Particle Protein (SRPP1). Protein/lipid interactions were screened using two models (lipid vesicles in solution or lipid monolayers at air/liquid interface). Calcein leakage, surface pressure, ellipsometry, microscopy and spectroscopy revealed that both REF1 and SRPP1 displayed stronger interactions with anionic POPA and POPG, as compared to zwitterionic POPC. A particular behavior of REF1 was observed when interacting with POPA monolayers (i.e. aggregation + modification of secondary structure from α-helices to ß-sheets, characteristic of its amyloid aggregated form), which might be involved in the irreversible coagulation mechanism of Hevea rubber particles.


Assuntos
Hevea , Fosfolipídeos , Fosfolipídeos/metabolismo , Hevea/química , Hevea/metabolismo , Látex/química , Látex/metabolismo , Fatores de Alongamento de Peptídeos/metabolismo , Estrutura Secundária de Proteína
19.
Int J Biol Macromol ; 253(Pt 2): 126782, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37690638

RESUMO

Latex is a colloidal suspension derived from the Hevea brasiliensis tree, derived from natural rubber, poly(isoprene), and assorted constituents including proteins and phospholipids. These constituents are inherent to both natural rubber and latex serum. This investigation was undertaken to examine the impact of the deproteinization process on chemical and biological dynamics of natural rubber latex. Natural Rubber (NR) extracted from the pure latex (LNCP) was obtained through centrifugation, followed by six rounds of solvent purification (LP6). The structure was characterized using Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), swelling test, surface zeta potential (ζ), scanning electron microscopy (SEM) and in vitro assay. The results revealed that the LP6 group presented decreased swelling kinetics, reduced cell adhesion and proliferation, and a smoother surface with decreased negative surface charge. Conversely, the LNCP group shown accelerated swelling, heightened adhesion and cellular growth, and a more negatively charged and rougher surface. As such, the attributes of latex serum and proteins have potential usage across numerous biomedical applications.


Assuntos
Hevea , Borracha , Borracha/química , Látex/química , Hevea/metabolismo , Fosfolipídeos/química , Microscopia Eletrônica de Varredura , Proteínas de Plantas/química
20.
Nat Plants ; 9(9): 1372, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37697001
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...