Fiber Elongation Research Articles

Overexpression of a ceramide synthase gene,GhCS1, inhibits fiber cell initiation and elongation by promoting the synthesis of ceramides containing dihydroxy LCB and VLCFA.

Cotton is an important natural fiber crop worldwide. Cotton fiber cell is regarded as an ideal material for studying the growth and development of plant cells. Sphingolipids are important components of biomembrane and bioactive molecules which participate in many processes such as plant growth, development regulation, stimulus sensing, and stress response. However, the functions of sphingolipids in the cotton fiber development are still unclear. In the present study, we identified a cotton ceramide synthase gene, GhCS1, which is predominantly expressed in fiber cell. The GhCS1 is located in the endoplasmic reticulum and has the conserved domains of ceramide synthase. Overexpression of GhCS1 gene inhibited both vegetative and reproductive growth in cotton. Importantly, the fiber cell initiation and elongation were severely inhibited when compared with control. Comparison of the sphingolipid profile in the 0-DPA (days past anthesis) ovule (with fiber cell) between control and transgenic cotton plants showed that the content of sphingosines (Sph) decreased significantly in transgenic ovules, whereas the content of phyto-sphingosines (Phyto-Sph) had no change. Meanwhile, the content of ceramide containing Sph and very-long-chain fatty acid (VLCFA) increased significantly in transgenic ovules, while ceramide containing Phyto-Sph and long-chain fatty acids (LCFA)/VLCFA significantly decreased. These results indicated that GhCS1 was a functional ceramide synthase, which preferentially used Sph and VLCFA as substrates and was different from the Arabidopsis ceramide synthase AtLOH1/AtLOH3, which preferentially used Phyto-Sph and VLCFA as substrates, and also different from AtLOH2, which preferentially used Sph and LCFA as substrates. It is suggested that GhCS1 might be a new ceramide synthase gene in the plant, play some roles in the development of fiber cells and cotton plants.

5-HT7 receptor-dependent intestinal neurite outgrowth contributes to visceral hypersensitivity in irritable bowel syndrome

AbstractIrritable bowel syndrome (IBS) is characterized by visceral hypersensitivity (VH) associated with abnormal serotonin/5-hydroxytryptamine (5-HT) metabolism and neurotrophin-dependent mucosal neurite outgrowth. The underlying mechanisms of VH remain poorly understood. We investigated the role of 5-HT7 receptor in mucosal innervation and intestinal hyperalgesia. A high density of mucosal nerve fibres stained for 5-HT7 was observed in colonoscopic biopsy specimens from IBS patients compared with those from healthy controls. Staining of 5-HT3 and 5-HT4 receptors was observed mainly in colonic epithelia with comparable levels between IBS and controls. Visceromotor responses to colorectal distension were evaluated in two mouse models, one postinfectious with Giardia and subjected to water avoidance stress (GW) and the other postinflammatory with trinitrobenzene sulfonic acid-induced colitis (PT). Increased VH was associated with higher mucosal density of 5-HT7-expressing nerve fibres and elevated neurotrophin and neurotrophin receptor levels in the GW and PT mice. The increased VH was inhibited by intraperitoneal injection of SB-269970 (a selective 5-HT7 antagonist). Peroral multiple doses of CYY1005 (a novel 5-HT7 ligand) decreased VH and reduced mucosal density of 5-HT7-expressing nerve fibres in mouse colon. Human neuroblastoma SH-SY5Y cells incubated with bacteria-free mouse colonic supernatant, 5-HT, nerve growth factor, or brain-derived neurotrophic factor exhibited nerve fibre elongation, which was inhibited by 5-HT7 antagonists. Gene silencing of HTR7 also reduced the nerve fibre length. Activation of 5-HT7 upregulated NGF and BDNF gene expression, while stimulation with neurotrophins increased the levels of tryptophan hydroxylase 2 and 5-HT7 in neurons. A positive-feedback loop was observed between serotonin and neurotrophin pathways via 5-HT7 activation to aggravate fibre elongation, whereby 5-HT3 and 5-HT4 had no roles. In conclusion, 5-HT7-dependent mucosal neurite outgrowth contributed to VH. A novel 5-HT7 antagonist could be used as peroral analgesics for IBS-related pain.

Appropriate software model for evaluating the effect of untreated and treated sisal fibre with different gauge length and strain rates for geotextile applications

Geotextiles are commonly used as reinforcement in building, engineering and road laying applications. The sisal fibre is one of the natural fibres which is used to reinforce soil and prevent damage. This sisal fibre is specifically helpful to fill gaps between roads to improve soil structure, and prevent soil erosion but allows the water to drain off. This paper is concerned with the study of the effect of gauge length on the strength and elongation of sisal fibres in untreated and treated states with sodium hydroxide at different concentrations and duration of treatment. The reason for applying sodium hydroxide treatment on sisal fibre is to remove the impurities from it and to improve the inter fibre adhesion with resin for producing a composite. The effective reinforcement of composites with plant fibres depends on the moisture content and the fibre matrix interfacial adhesion. Treatment with alkali improves the performance of fibres when they are used as composites. Also, the effect of strain rate on the strength and elongation of sisal in untreated and treated states has been investigated. The Weibull modelling software model has been used in many studies to quantify the degree of variability in the fibres. This paper deals with the application of an appropriate software model such as the Weibull distribution model for quantifying the variability in strength and elongation at different gauge lengths varied from 10 mm to 100 mm and also varied the strain rate from 10 mm/min to 500 mm/min. In addition to the Weibull distribution model, air plasma treatment and SEM (Scanning Electron Microscope) analysis on sisal fibre were also carried out in this paper. The result shows that the sisal fibre is more suitable for geotextile applications.

How the Nonwoven Polymer Volume Microstructure Is Transformed under Tension in an Aqueous Environment.

The fibrous porous structure of polymers can mimic the extracellular matrix of the native tissue, therefore such polymers have a good potential for use in regenerative medicine. Organs and tissues within the body exhibit different mechanical properties depending on their functionality, thus artificial scaffolds should have mechanical behaviors similar to the extracellular matrix in conditions like living organisms, primarily in aqueous media. Several methods have been investigated in aquatic environments, including noninvasive techniques based on ultrasonic focused beams for biological objectives. In this study we explored the tensile behavior of poly(L-lactide) nonwoven polymer scaffolds using high-frequency ultrasound microscopy combined with a horizontal testing machine, which provided a visualization of the reorganization and transformation of the dynamic volume microstructure. The mechanisms of unwinding, elongation, orientation, and deformation of polymer fibers under uniaxial tension were revealed. We observed an association between the lined plastic deformation from 100 to 400% and the formation of multiple necks in the fibers, which caused stress relaxation and significant rarefaction of the fibrous microstructure. It was shown that both peaks on the stress–strain curve corresponded to the microstructure of aligned fibers in terms of initial diameter and thinning fibers. We discuss the possible influence of these microstructure transformations on cell behavior.

A deletion/duplication in the Ligon lintless-2 locus induces siRNAs that inhibit cotton fiber cell elongation.

Most cultivated cotton (Gossypium hirsutum L.) varieties have two types of seed fibers: short fuzz fiber strongly adhered to the seed coat, and long lint fiber used in the textile industry. The Ligon lintless-2 (Li2) cotton mutant has a normal vegetative phenotype but produces very short lint fiber on the seeds. The Li2 mutation is controlled by a single dominant gene. We discovered a large structural rearrangement at the end of chromosome D13 in the Li2 mutant based on whole-genome sequencing and genetic mapping of segregating populations. The rearrangement contains a 177-kb deletion and a 221-kb duplication positioned as a tandem inverted repeat. The gene Gh_D13G2437 is located at the junction of the inverted repeat in the duplicated region. During transcription such structure spontaneously forms self-complementary hairpin RNA of Gh_D13G2437 followed by production of small interfering RNA (siRNA). Gh_D13G2437 encodes a Ran-Binding Protein 1 (RanBP1) that preferentially expresses during cotton fiber elongation. The abundance of siRNA produced from Gh_D13G2437 reciprocally corresponds with the abundance of highly homologous (68%-98% amino acid sequence identity) RanBP1 family transcripts during fiber elongation, resulting in a shorter fiber phenotype in the Li2. Overexpression of Gh_D13G2437 in the Li2 mutant recovered the long lint fiber phenotype. Taken together, our findings revealed that siRNA-induced silencing of a family of RanBP1s inhibit elongation of cotton fiber cells in the Li2 mutant.

Genome-Wide Identification and Expression Analyses of the Cotton AGO Genes and Their Potential Roles in Fiber Development and Stress Response.

Argonaute proteins (AGOs) are indispensable components of RNA silencing. However, systematic characterization of the AGO genes have not been completed in cotton until now. In this study, cotton AGO genes were identified and analyzed with respect to their evolution and expression profile during biotic and abiotic stresses. We identified 14 GaAGO, 14 GrAGO, and 28 GhAGO genes in the genomes of Gossypium arboreum, Gossypium raimondii, and Gossypium hirsutum. Cotton AGO proteins were classified into four subgroups. Structural and functional conservation were observed in the same subgroups based on the analysis of the gene structure and conserved domains. Twenty-four duplicated gene pairs were identified in GhAGO genes, and all of them exhibited strong purifying selection during evolution. Moreover, RNA-seq analysis showed that most of the GhAGO genes exhibit high expression levels in the fiber initiation and elongation processes. Furthermore, the expression profiles of GhAGO genes tested by quantitative real-time polymerase chain reaction (qPCR) demonstrated that they were sensitive to Verticillium wilt infection and salt and drought stresses. Overall, our results will pave the way for further functional investigation of the cotton AGO gene family, which may be involved in fiber development and stress response.

Charge Transport in Twisted Organic Semiconductor Crystals of Modulated Pitch.

Many molecular crystals (approximately one third) grow as twisted, helicoidal ribbons from the melt, and this preponderance is even higher in restricted classes of materials, for instance, charge-transfer complexes. Previously, twisted crystallites of such complexes present an increase in carrier mobilities. Here, the effect of twisting on charge mobility is better analyzed for a monocomponent organic semiconductor, 2,5-bis(3-dodecyl-2-thienyl)-thiazolo[5,4-d]thiazole (BDT), that forms twisted crystals with varied helicoidal pitches and makes possible a correlation of twist strength with carrier mobility. Films are analyzed by X-ray scattering and Mueller matrix polarimetry to characterize the microscale organization of the polycrystalline ensembles. Carrier mobilities of organic field-effect transistors are five times higher when the crystals are grown with the smallest pitches (most twisted), compared to those with the largest pitches, along the fiber elongation direction. A tenfold increase is observed along the perpendicular direction. Simulation of electrical potential based on scanning electron microscopy images and density functional theory suggests that the twisting-enhanced mobility is mainly controlled by the fiber organization in the film. A greater number of tightly packed twisted fibers separated by numerous smaller gaps permit better charge transport over the film surface compared to fewer big crystallites separated by larger gaps.

Responses to dietary supplementation with field bean (Vicia faba var. minor) in production indices, mohair growth and hormonal parameters in transition Angora goats

Twenty-two pluriparous single-foetus-bearing Angora goats, housed 3 weeks pre-partum in mid-December, and in transition from pregnancy to lactation were used to test the efficacy of post-partum supplementation (Group S: 11 goats) or not (Group C: 11 goats) with 300 g/head/day of whole field bean seeds (WFBS) to a diet based on mixed hay ad libitum and natural pasture. The goats were maintained with the suckling of their kids for 90 days. Significant decreases in liveweight (LW) and body condition score (BCS), were documented post-parturition in both groups and were then maintained throughout. These suggest a mobilisation in body tissue that was not mitigated by WFBS supplementation. However, the faster growth of the suckled kids and greater elongation of mohair fibre recorded (Group S > Group C), suggested improvement in partition towards production indices of lactation and hair fibre deposition, respectively. Greater concentrations of total thyroid hormones, T3 and T4 in supplemented does were recorded. Overall mean (pre-prandial) plasma insulin concentrations, not different between treatments, decreased (p < 0.5) from pre-partum concentration, and showed a pattern in time, similar to that of LW and BCS. Insulin appeared not to contribute to the suggested lactational and hair growth effects and possibly contributed to transition by a homeorhetic-type reduction in concentration post-partum. Mean plasma insulin-like growth factor-1 (IGF-1) concentrations trended lower due to supplementation from 3 weeks after kidding. It is concluded that WFBS supplementation was efficacious in improving production indices of the transition Angora goats. The feeding of different quantities of WFBS should be investigated. HIGHLIGHTS Supplementation of transition Angora goats with field bean did not affect the loss of body weight or body condition score occurring after kidding. Supplementation with field bean induced higher concentrations of blood thyroid hormones, without affecting post-partum reductions in insulin. Supplemented dams had a greater mohair elongation rate and their kids grew more, by likely preferential partition to hair growth and lactation, rather than other body tissues.

Selection of Natural Fibre for Pultruded Hybrid Synthetic/Natural Fibre Reinforced Polymer Composites Using Analytical Hierarchy Process for Structural Applications

Application of synthetic fibres in composites has been raising environmental issues due to carbon emissions from the production site and reliability on non-renewable resources upon production. Hence, this research sets as a preliminary study to select suitable natural fibres to be hybridized with glass fibres for the development of sustainable and high-performance hybrid composites as potential alternative to conventional pultruded fibreglass composites in structural profile applications. In this study, analytical hierarchy process (AHP) was conducted to select the ideal natural fibre as reinforcement in the hybrid pultruded FRP composites suitable for structural applications. Hence, 13 natural fibre candidates were selected as alternatives and six criteria were chosen and analysed to select the best candidate for pultruded hybrid FRP. Criteria such as tensile strength, tensile modulus, density, cellulose content, elongation, and availability of fibres were assigned as the standard of selecting natural fibres for the application intended in this study. Among the 13 alternatives, kenaf was found to be the most suitable reinforcement for the application as it yielded the highest priority vector at 0.1. The results were then validated by carrying out sensitivity analysis to ensure kenaf is the most suitable material for the research.

MTORC2 mediates structural plasticity in distal nociceptive endings that contributes to pain hypersensitivity following inflammation

The encoding of noxious stimuli into action potential firing is largely mediated by nociceptive free nerve endings. Tissue inflammation, by changing the intrinsic properties of the nociceptive endings, leads to nociceptive hyperexcitability and thus to the development of inflammatory pain. Here, we showed that tissue inflammation–induced activation of the mammalian target of rapamycin complex 2 (mTORC2) triggers changes in the architecture of nociceptive terminals and leads to inflammatory pain. Pharmacological activation of mTORC2 induced elongation and branching of nociceptor peripheral endings and caused long-lasting pain hypersensitivity. Conversely, nociceptor-specific deletion of the mTORC2 regulatory protein rapamycin-insensitive companion of mTOR (Rictor) prevented inflammation-induced elongation and branching of cutaneous nociceptive fibers and attenuated inflammatory pain hypersensitivity. Computational modeling demonstrated that mTORC2-mediated structural changes in the nociceptive terminal tree are sufficient to increase the excitability of nociceptors. Targeting mTORC2 using a single injection of antisense oligonucleotide against Rictor provided long-lasting alleviation of inflammatory pain hypersensitivity. Collectively, we showed that tissue inflammation–induced activation of mTORC2 causes structural plasticity of nociceptive free nerve endings in the epidermis and inflammatory hyperalgesia, representing a therapeutic target for inflammatory pain.

Genome-wide characterization of the Rho family in cotton provides insights into fiber development

BackgroundCotton is the source of natural fibers globally, fulfilling 90% of the textile industry's requirements. However, fiber development is a complex biological process comprising four stages. Fiber develops from a single cell, and cell elongation is a vital process in fiber development. Therefore, it is pertinent to understand and exploit mechanisms underlying cell elongation during fiber development. A previous report about cell division control protein 42 (CDC-42) with its key role in cell elongation in eukaryotes inspired us to explore its homologs Rho GTPases for understanding of cell elongation during cotton fiber development.ResultWe classified 2 066 Rho proteins from 8 Gossypium species into 5 and 8 groups within A and D sub-genomes, respectively. Asymmetric evolution of Rho members was observed among five tetraploids. Population fixation statistics between two short and long fiber genotypes identified highly diverged regions encompassing 34 Rho genes in G. hirustum, and 31 of them were retained through further validation by genome wide association analysis (GWAS). Moreover, a weighted gene co-expression network characterized genome-wide expression patteren of Rho genes based on previously published transcriptome data. Twenty Rho genes from five modules were identified as hub genes which were potentially related to fiber development. Interaction networks of 5 Rho genes based on transcriptional abundance and gene ontology (GO) enrichment emphasized the involvement of Rho in cell wall biosynthesis, fatty acid elongation, and other biological processes.ConclusionOur study characterized the Rho proteins in cotton, provided insights into the cell elongation of cotton fiber and potential application in cotton fiber improvement.

Expressed genes and their new alleles identification during fibre elongation reveal the genetic factors underlying improvements of fibre length in cotton.

SummaryInterspecific breeding in cotton takes advantage of genetic recombination among desirable genes from different parental lines. However, the expression new alleles (ENAs) from crossovers within genic regions and their significance in fibre length (FL) improvement are currently not understood. Here, we generated resequencing genomes of 191 interspecific backcross inbred lines derived from CRI36 (Gossypium hirsutum) × Hai7124 (Gossypium barbadense) and 277 dynamic fibre transcriptomes to identify the ENAs and extremely expressed genes (eGenes) potentially influencing FL, and uncovered the dynamic regulatory network of fibre elongation. Of 35 420 eGenes in developing fibres, 10 366 ENAs were identified and preferentially distributed in chromosomes subtelomeric regions. In total, 1056–1255 ENAs showed transgressive expression in fibres at 5–15 dpa (days post‐anthesis) of some BILs, 520 of which were located in FL‐quantitative trait locus (QTLs) and GhFLA9 (recombination allele) was identified with a larger effect for FL than GhFLA9 of CRI36 allele. Using ENAs as a type of markers, we identified three novel FL‐QTLs. Additionally, 456 extremely eGenes were identified that were preferentially distributed in recombination hotspots. Importantly, 34 of them were significantly associated with FL. Gene expression quantitative trait locus analysis identified 1286, 1089 and 1059 eGenes that were colocalized with the FL trait at 5, 10 and 15 dpa, respectively. Finally, we verified the Ghir_D10G011050 gene linked to fibre elongation by the CRISPR‐cas9 system. This study provides the first glimpse into the occurrence, distribution and expression of the developing fibres genes (especially ENAs) in an introgression population, and their possible biological significance in FL.

Data mining of transcriptional biomarkers at different cotton fiber developmental stages.

Advancement of the gene expression study provides comprehensive information on pivotal genes at different cotton fiber development stages. For the betterment of cotton fiber yield and their quality, genetic improvement is a major target point for the cotton community. Therefore, various studies were carried out to understand the transcriptional machinery of fiber leading to the detailed integrative as well as innovative study. Through data mining and statistical approaches, we identified and validated the transcriptional biomarkers for staged specific differentiation of fiber. With the unique mapping read matrix of ~ 200 cotton transcriptome data and sequential statistical analysis, we identified several important genes that have a deciding and specific role in fiber cell commitment, initiation and elongation, or secondary cell wall synthesis stage. Based on the importance score and validation analysis, IQ domain 26, Aquaporin, Gibberellin regulated protein, methionine gamma lyase, alpha/beta hydrolases, and HAD-like superfamily have shown the specific and determining role for fiber developmental stages. These genes are represented as transcriptional biomarkers that provide a base for molecular characterization for cotton fiber development which will ultimately determine the high yield.

Identification and validation of SSRS linked to fiber quality traits in cotton using RILs derived from Gossypium hirsutum var. MCU5 and TCH 1218

In order to increase the fiber productivity in cotton, it is imperative to genetically improve the fiber component traits and such effort can be quickened by use of molecular markers. Totally, seventy-four simple sequence repeat (SSR) markers that were previously shown to be linked to fibre strength, boll weight, and fibre elongation were used to differentiate Gossypium hirsutum var. MCU5 and TCH1218 and among them two were found to be polymorphic markers. These two polymorphic markers viz., TMB 0409 and CGR 6889 were used to genotype 220 F13 recombinant inbred lines (RILs) derived from MCU5 and TCH1218 and single marker analysis was used to confirm their linkage with target traits using the phenotypic data collected on cotton fiber yield component traits such as plant height, days to 50 percent flowering data, boll weight, number of monopodial and sympodial branches and bolls. These identified and validated markers across genetic background can be employed to genetically improve cotton through marker assisted selection.

Electron beam irradiation assisted preparation of UHMWPE fiber with 3D cross-linked structure and outstanding creep resistance

A high creep resistance UHMWPE fiber was prepared by electron beam (EB) irradiation. The UHMWPE fiber samples impregnated with antioxidants were irradiated in air by an electron accelerator and then annealed. The irradiated fibers exhibited higher thermal decomposition temperature, smaller crystalline size and high degree of cross-linking than the initial fiber. The gel content of radiation cross-linking fiber was up to 88%, indicating that cross-linking reaction had occurred between the molecular chains in amorphous region, which greatly reduced the slippage of the molecular chains. The creep curves of the modified fibers were obtained by a stable creep test method. At room temperature, the creep elongation of radiation cross-linked fibers reduced by more than 30%. Compared with unmodified UHMWPE fiber, cross-linked UHMWPE fibers still exhibited excellent creep resistance at high temperatures and the optimal absorbed dose was 100 kGy. In addition, the radial shrinkage of the fiber caused by radiation cross-linking further proved the irradiation-induced cross-linking reaction in the fibers. The study provides a simple modification strategy for the preparation and characterization of high creep resistance UHWMPE fiber, which is beneficial to broaden the application, especially for military protection products.

Retrieving a disrupted gene encoding phospholipase A for fibre enhancement in allotetraploid cultivated cotton

SummaryAfter polyploidization originated from one interspecific hybridization event in Gossypium, Gossypium barbadense evolved to produce extra‐long staple fibres than Gossypium hirsutum (Upland cotton), which produces a higher fibre yield. The genomic diversity between G. barbadense and G. hirsutum thus provides a genetic basis for fibre trait variation. Recently, rapid accumulation of gene disruption or deleterious mutation was reported in allotetraploid cotton genomes, with unknown impacts on fibre traits. Here, we identified gene disruptions in allotetraploid G. hirsutum (18.14%) and G. barbadense (17.38%) through comparison with their presumed diploid progenitors. Relative to conserved genes, these disrupted genes exhibited faster evolution rate, lower expression level and altered gene co‐expression networks. Within a module regulating fibre elongation, a hub gene experienced gene disruption in G. hirsutum after polyploidization, with a 2‐bp deletion in the coding region of GhNPLA1D introducing early termination of translation. This deletion was observed in all of the 34 G. hirsutum landraces and 36 G. hirsutum cultivars, but not in 96% of 57 G. barbadense accessions. Retrieving the disrupted gene GhNPLA1D using its homoeolog GhNPLA1A achieved longer fibre length in G. hirsutum. Further enzyme activity and lipids analysis confirmed that GhNPLA1A encodes a typical phospholipase A and promotes cotton fibre elongation via elevating intracellular levels of linolenic acid and 34:3 phosphatidylinositol. Our work opens a strategy for identifying disrupted genes and retrieving their functions in ways that can provide valuable resources for accelerating fibre trait enhancement in cotton breeding.

Extraction of Natural Dyes from Turmeric (Curcuma longa) and their Application on Polylactic Acid Fiber

This research presents an eco-friendly approach towards Response Surface Methodology (RSM). The current study is based on the optimization of the dyeing process of biodegradable polylactic acid (PLA) fiber using with natural dyes of turmeric extractions by using Soxhlet extraction technique. The dyeing process was carried out by using Daelim Starlet III, which is an infrared dyeing machine. Three independent variables were selected, including pH, time, and temperature. According to the standard test protocols, dyed samples were evaluated for color strength (K/S), CIELab values, fiber tenacity, and fiber elongation. ANOVA test results of the Linear Model exhibited that the model terms have a significant effect on K/S and the physical strength of fiber. Moreover, the observed values were in agreement with the predicted values and the suggested equation model was satisfactory and accurate. A temperature of 100 °C with pH 5 and time duration of 30 minutes in the dyeing process were observed to achieve optimum dyed PLA fibers, exhibiting appreciable strength and elongation. Lastly, dyed fibers exhibited satisfactory color fastness ratings.&#x0D; Index Terms: color strength, exhaustion, natural dyeing, polylactic acid fiber, turmeric

Effect of glass fiber hybridization on the mechanical properties of unidirectional, alkali‐treated kenaf‐epoxy composites

AbstractDue to environmental issues and high cost of synthetic fibers, natural or cellulosic fibers have emerged as a promising reinforcement for polymer composites. The hybridization of natural fiber with synthetic fiber is a useful technique to improve the mechanical properties instead of using the natural fibers alone. This research aims to evaluate the influence of glass fiber hybridization on the mechanical properties of continuous, unidirectional, alkali (NaOH)‐treated kenaf‐epoxy composites. At first, the effect of treatment of various concentrations (3, 5, 7, and 9% w/v) of NaOH on the structure of single kenaf fiber was characterized using XRD, SEM, FTIR, and tensile testing. At the optimum 5% alkali concentration the tensile strength, modulus, and %elongation of the kenaf fibers were enhanced by 81%, 114%, and 42%, respectively. The effect of hybridization of 5% NaOH treated kenaf along with glass fiber on the improvement in tensile, flexural, and impact properties for hand laid kenaf‐glass‐epoxy hybrid composite laminates was established. The overall matrix to fiber weight ratio of five different layup sequence laminates was maintained constant at 70:30. It can be concluded from the obtained results that the 15% glass and 15% kenaf fiber hybridized composites exhibited the maximum increment in tensile strength and modulus (68.5% and 19.5%, respectively) in comparison to the unhybridized composites. Further, the flexural strength and modulus were also improved by 21% and 67%, respectively, and the impact strength by 153%. The SEM fractography proved that alkali treatment of fibers improved the fiber‐matrix interfacial bonding whereas fiber breakage, fiber pull‐out and debonding were established as the main fracture mechanisms of hybrid composites. The findings of the present investigation on kenaf‐glass hybrid composites corroborate that they are suitable for secondary structural applications in construction and automobile sectors.

GhBZR3 suppresses cotton fiber elongation by inhibiting very-long-chain fatty acid biosynthesis.

SUMMARYThe BRASSINAZOLE‐RESISTANT (BZR) transcription factor is a core component of brassinosteroid (BR) signaling and is involved in the development of many plant species. BR is essential for the initiation and elongation of cotton fibers. However, the mechanism of BR‐regulating fiber development and the function of BZR is poorly understood in Gossypium hirsutum L. (cotton). Here, we identified a BZR family transcription factor protein referred to as GhBZR3 in cotton. Overexpression of GhBZR3 in Arabidopsis caused shorter root hair length, hypocotyl length, and hypocotyl cell length, indicating that GhBZR3 negatively regulates cell elongation. Pathway enrichment analysis from VIGS‐GhBZR3 cotton plants found that fatty acid metabolism and degradation might be the regulatory pathway that is primarily controlled by GhBZR3. Silencing GhBZR3 expression in cotton resulted in taller plant height as well as longer fibers. The very‐long‐chain fatty acid (VLCFA) content was also significantly increased in silenced GhBZR3 plants compared with the wild type. The GhKCS13 promoter, a key gene for VLCFA biosynthesis, contains two GhBZR3 binding sites. The results of yeast one‐hybrid, electrophoretic mobility shift, and luciferase assays revealed that GhBZR3 directly interacted with the GhKCS13 promoter to suppress gene expression. Taken together, these results indicate that GhBZR3 negatively regulates cotton fiber development by reducing VLCFA biosynthesis. This study not only deepens our understanding of GhBZR3 function in cotton fiber development, but also highlights the potential of improving cotton fiber length and plant growth using GhBZR3 and its related genes in future cotton breeding programs.

The XTH Gene Family in Schima superba: Genome-Wide Identification, Expression Profiles, and Functional Interaction Network Analysis.

Xyloglucan endotransglucosylase/hydrolase (XTH), belonging to glycoside hydrolase family 16, is one of the key enzymes in plant cell wall remodeling. Schima superba is an important timber and fireproof tree species in southern China. However, little is known about XTHs in S. superba. In the present study, a total of 34 SsuXTHs were obtained, which were classified into three subfamilies based on the phylogenetic relationship and unevenly distributed on 18 chromosomes. Furthermore, the intron–exon structure and conserved motif composition of them supported the classification and the members belonging to the same subfamily shared similar gene structures. Segmental and tandem duplication events did not lead to SsuXTH gene family expansion, and strong purifying selection pressures during evolution led to similar structure and function of SsuXTH gene family. The interaction network and cis-acting regulatory elements analysis revealed the SsuXTH expression might be regulated by multiple hormones, abiotic stresses and transcription factors. Finally, expression profiles and GO enrichment analysis showed most of the tandem repeat genes were mainly expressed in the phloem and xylem and they mainly participated in glycoside metabolic processes through the transfer and hydrolysis of xyloglucan in the cell wall and then regulated fiber elongation.