Fiber Development Research Articles

Ultra‐High Radial Elastic Aerogel Fibers for Thermal Insulation Textile

AbstractWhen nanoporous aerogels with excellent thermal insulation performance are processed into 1D fibers, they have great potential for application in the field of personal thermal management. However, coping with the impact of external forces, especially radial extrusion, and maintaining the macro morphology and microstructure of aerogels during use are remaining issues. To address these challenges, this study proposes a method that uses ultrafine and ultra‐highly entangled bacterial cellulose nanofibers as the basis to achieve high radial elasticity by forming an isomorphic coating of rigid silica on the soft gel skeleton of aerogel fibers. The obtained aerogel fibers can achieve an elastic recovery of 88% over 50 compression cycles under 90% strain, and they can be knotted, woven into textiles, and are washable. This strategy improves the radial compression resistance of aerogel fibers, providing rich possibilities for the development of aerogel fibers with excellent mechanical properties.

Fibin is a crucial mitochondrial regulatory gene in skeletal muscle development.

Fin bud initiation factor homolog (Fibin) is a secreted protein that is relatively conserved among species. It is closely related to fin bud development and can regulate a variety of cellular processes. In our previous high-throughput chromosome conformation capture (Hi-C) study of pig embryonic muscle development, it was found that Fibin has high expression and activity during the development of pig primary muscle fibers. Therefore, we speculated Fibin participated in myogenesis severely. Specific deletion of Fibin in mouse skeletal muscle resulted in abnormal primary muscle fiber development during the embryonic period and a substantial decrease in skeletal muscle mass in adulthood. In vitro, knocking out Fibin in C2C12 cells promoted cell proliferation; however, after myogenic induction, cells lacking Fibin had almost no ability to differentiate into myotubes. During myogenic differentiation, loss of Fibin disrupts the normal function of mitochondria and impairs oxidative phosphorylation, resulting in decrease of NADH and FADH in the electron transport chain. Transmission electron microscopy also showed that mitochondrial morphology of Fibin-deficient C2C12 was impaired. In conclusion, our research has unveiled a novel mechanism of myogenesis regulation in mitochondrial function and potential target Fibin, and improved understanding of a broad range of mitochondrial muscle diseases.

Development and Characterization of Mikania, Kapok, Wool, Sugarcane, and Pineapple Fiber Reinforced Polyester Composite

ABSTRACTThis study utilizes plant‐derived fibers including Mikania, wool, kapok, sugarcane, and pineapple as strengthening additions to fabricated and tested reinforced polyester mixtures. This study aimed to examine the mechanical qualities and potential applications of these natural materials in boosting the effectiveness of polyester composites. The composites were formed by including natural fibers into a polyester base using a hand lay‐up preparation method. The finished samples received a complete assessment, covering tensile and impact testing as well as SEM analysis. The findings showed that incorporating natural materials like Mikania vines, wool, kapok fuzz, sugarcane fibers, and pineapple leaves had a notably positive effect on the mechanical features of the plastic composites. The tensile strength of the material combined pineapple was particularly high, achieving a maximum stress of 42.4822 N/mm2 and a maximum stretch of 4.27950%. Similarly, that same composite exhibited a maximum stretch of 3.75753% and a maximum stress of 77.4922 N/mm2 during the bending experiment. The substances exhibiting the strongest impact endurance, as determined by the impact assessment, included kapok, Mikania, wool, pineapple, and sugarcane. The kapok provided an impact toughness of 1.2 N m, which was somewhat elevated. This research offers a precious understanding of using natural fibers as strengthening additives in polyester composites, demonstrating their flexible perspective for many uses. The discoveries present hopeful possibilities for additional examination and progression in composite materials, consequently advancing the development of sustainable materials.

Transcriptomics and Metabolomics Explain the Crisping Mechanisms of Broad Bean-Based Crisping Diets on Nile Tilapia (Orechromis niloticus)

Background/Objectives: To investigate the crisping mechanism of broad bean-based crisping diets on Nile Tilapia. Methods: Four crisping diets were designed to feed 360 fish for 90 days, and multiomics analyses were employed. Results: Our results indicated that the designed crisping diets for Nile tilapia can effectively make tilapia muscle crispy. The ingestion of broad bean-based diets induced metabolic reprogramming dominated by glycolytic metabolism inhibition in fish, and metabolic reprogramming is the initiator of muscle structural remodeling. Among these, glucose is the main DAMP to be recognized by cellular PRRs, activating further immune response and oxidative stress and finally resulting in muscle change. Conclusions: Based on our results of multiomics, pck2, and ldh played main roles in crisping molecular mechanisms in driving the initial metabolic reprogram. Moreover, the addition of the crisping package further activated the ErbB signaling pathway and downstream MAPK signaling pathway to strengthen immune response, promoting muscle fiber development and growth. Our study delved into the effects of crisping formula diet on the liver of Nile tilapia at the molecular level, providing theoretical guidance for the nutritional regulation of crispy Nile tilapia.

Non-Circular Cross-Section Fibres for Composite Reinforcement—A Review with a Focus on Flat Glass Fibres

Glass fibre reinforcements form the backbone of the composites industry. Today, glass fibre products account for more than 95% of the fibre reinforcements used in the composites industry. Since the first commercialisation of glass fibres for composite reinforcement in the 1930s, the cross-sectional shape of glass fibres has remained exclusively circular. However, many of the other types of fibre reinforcement have a non-circular cross section (NCCS). This paper reviews the available knowledge on the production of NCCS glass fibres and some of the possibilities that such fibres offer to enhance the performance of glass reinforced polymer composites. The three parts of the review focus on early research work on different shapes of glass fibre, the developments leading to industrial-level production of NCCS glass fibres, and the more recent data available on the influence of the available commercially produced NCCS flat glass fibres on composite performance. It Is concluded that the continued development of NCCS glass fibres may offer interesting potential to generate composites with increased performance and may also enable further tailoring of composite performance to enable new applications to be developed.

GhDOFD45 promotes sucrose accumulation in cotton seeds by transcriptionally activating GhSWEET10 expression.

Cotton seed development and fiber elongation are the inseparable and overlapped development processes requiring the continuous supply of sucrose as the direct carbon source. However, little is known about the molecular mechanism of how sucrose is transported from the source tissues (leaves) into growing cotton seeds. Here, we identify the function of a sucrose transporter gene, Sugars Will Eventually be Exported Transporter 10, GhSWEET10 in cotton seed development. GhSWEET10 encodes a functional sucrose transporter, predominantly expressing in the funiculus, inner seedcoat, and endosperm during fiber elongation. GhSWEET10 RNAi plants (GhSWEET10i) accumulated less sucrose and glucose in growing seeds and that led to shorter fibers and smaller seeds, whereas GhSWEET10 overexpressed plants (GhSWEET10OE) had bigger seeds and longer fibers with more sugar accumulation during fiber elongation. GhSWEET10 gene is transcriptionally controlled by the transcription factor GhDOFD45. GhDOFD45 knockout plants (GhDOFD45-KO) possessed the phenotypes of smaller seeds and shorter fibers like those of GhSWEET10i plants. Furthermore, GhSWEET10 mainly exports the sucrose from the funiculus into developing seeds according to the mimic-analysis of sucrose transporting. Collectively, all these findings show that GhDOFD45 positively regulates GhSWEET10 expression to mainly transport sucrose from leaves into developing cotton seeds. Our findings also imply that the sucrose transport into enlarging seeds benefits fiber development, and thus GhSWEET10 can be selected as a target of breeding novel cotton varieties with larger and more vigorous seeds.

Development of a novel DNA-shaped steel fiber and its performance on fresh and hardened concrete

Adding small discrete random fibers in concrete has enhanced concrete behavior in various ways. Diverse types of fibers are available in terms of materials, shapes, and applications. Different shapes of steel fibers are available like hooked ends, crimped, stranded, helix, spherical, etc. Having the grade of concrete and the fiber dosage added as constant, the structural behavior and performance will vary for different types of fibers. It shows that the shape of fiber has a great role in enhancing the properties of concrete. The challenges in existing two-dimensional steel fibers in concrete like the mechanism and contribution of fiber in arresting cracks developed in all directions and balling effect can be overcome by a new type of three-dimensional steel fiber. A novel three-dimensional DNA-shaped steel fiber is designed and fabricated. This paper presents the fresh concrete and hardened concrete properties of DNA-shaped fiber-reinforced concrete (DNAFRC) and compares it with hooked-end fiber-reinforced concrete (HEFRC) by incorporating a volume fraction varying from 0.5 to 2% of grade M30 concrete and aspect ratio of 60 for both fibers. The fresh properties of concrete were evaluated by measuring the slump for workability and wash-out test for the fiber distribution. The hardened concrete properties were assessed by compressive, split tensile, flexural, impact, shear, and pull-out strength which demonstrated considerable increase by 5% at 1.5% volume fraction, 32%, 136%, 21%, and 35% at 2% volume fraction respectively for DNAFRC than the HEFRC. Scanning Electronic Microscope (SEM) images were studied on failed samples to evaluate the bonding of DNA fiber with concrete.

Histochemical and gene expression changes in Cannabis sativa hypocotyls exposed to increasing concentrations of cadmium and zinc

Hemp (Cannabis sativa L.) is a versatile crop that produces cellulosic bast fibres used in textiles and biocomposites. Is also finds use in phytoremediation, being a good candidate for the cultivation on marginal lands, such as those contaminated by heavy metals (HMs). HMs like cadmium (Cd) and zinc (Zn) are known to affect plant growth and impair the biosynthesis of cellulose and lignin at the cell wall level. Since cellulose is the major component in the gelatinous layer of bast fibres, HMs can impact the structure of hemp fibres and, consequently, their mechanical properties. This study investigates how varying concentrations of Cd and Zn in the soil affect the bast fibres of hemp plantlets. The chosen model is the hypocotyl, as it is ideal for studying bast fibre development: it exhibits a temporal separation between the elongation and thickening phases within a short period of approximately three weeks. C. sativa plantlets were grown for 20 days, and the hypocotyls sampled to perform histochemical observations, gene expression analysis, as well as to quantify biomass yield and Cd/Zn accumulation. Hemp plantlets grown in soils with the three highest Zn concentrations were smaller than the control group, whereas no decrease in size was observed under elevated Cd concentrations. However, at the highest Cd concentration, the root system exhibited enhanced development, accompanied by a significant increase in dry weight across all the concentrations tested. The quantification of Cd and Zn showed that the roots were the main organs accumulating HMs. Cd at the two highest concentrations decreased significantly the lumen area of bast fibres and increased their cell wall thickness. Zn decreased significantly the lumen area, but it did not impact the thickness of the cell wall at the highest concentration. Cd also increased the number of secondary fibres. Immunohistochemistry highlighted a different pattern of crystalline cellulose distribution with a signal that was less homogeneous in the presence of Cd and Zn. Gene expression analysis revealed changes in transcripts encoding cellulose synthases, fasciclin-like arabinogalactan proteins, class III peroxidases. The results obtained shed light on the molecular response and bast fibre histological changes occurring in young hemp plants exposed to Cd and Zn.

Comparative Lipidomics Analysis Provides New Insights into the Metabolic Basis of Color Formation in Green Cotton Fiber.

Green fiber (GF) is a naturally colored fiber. A limited understanding of its color formation mechanism restricts the improvement of colored cotton quality. This experiment used upland cotton green fiber germplasm 1-4560 and genetic inbred line TM-1; the lipid profiles of green fibers at 30 (white stage) and 35 days post-anthesis (DPA) (early greening stage), as well as those of TM-1 at the same stages, were revealed. Among the 109 differential types of lipids (DTLs) unique to GF, the content of phosphatidylserine PS (16:0_18:3) was significantly different at 30 and 35 DPA. It is speculated that this lipid is crucial for the pigment accumulation and color formation process of green fibers. The 197 DTLs unique to TM-1 may be involved in white fiber (WF) development. Among the shared DTLs in GF35 vs. GF30 and WF35 vs. WF30, sulfoquinovosyldiacyl-glycerol SQDG (18:1_18:1) displays a significant difference in the content change between green fibers and white fibers, potentially affecting color formation through changes in content. The enriched metabolic pathways in both comparison groups are relatively conserved. In the most significantly enriched glycerophospholipid metabolic pathway, 1-acyl-sn-glycero-3-phosphocholine (C04230) only appears in white cotton. This indicates differences in the metabolic pathways between white and green fibers, potentially related to different mechanisms of color formation and fiber development. These findings provide a new theoretical basis for studying cotton fiber development and offer important insights into the specific mechanism of green fiber color formation.

Fiber morphological characteristics of bamboo Ferrocalamus strictus culms from different geographical distribution regions

The fiber index including fiber length, width, wall thickness and lumen diameter of Ferrocalamus strictus culms (1, 2, and ≥ 3 years) from Jinping, Mojiang and Lvchun counties of Yunnan Province was determined and the elemental content of the soil was also determined to analyze the fiber characteristics. The average relative fiber index measured for F. strictus culms were fiber length (1.30 mm), width (21.57 μm), slenderness ratio (60.79 μm), wall thickness (4.21 μm), lumen diameter (7.22 μm), and runkel ratio (1.22 μm), which belonged to the range of middle and long fibers. The fiber length increased with the culm age. The proportion of long fiber increased while short fibers decreased along with culm maturing. The fiber morphology did not show a specific trend with the culm height. Fiber length reached the maximum in the bottom portions of the culms. There is a correlation between fiber morphology and soil elements, the content of organic matter, total potassium, total sulfur, total aluminum, total zinc, total iron, total boron, alkali-hydrolyzed nitrogen and available silicon in the soil affects fiber morphology. The content of organic matter, total boron and alkali-hydrolyzed nitrogen in the soil from Mojiang County was largest. Comparatively, the culm fiber in Mojiang County had the best fiber index performance for utilization, since the greatest proportion of medium and long fibers and the optimal distribution of fiber length frequency was obtained from the culms in Mojiang County. This study can provide a theoretical basis for large-scale bamboo forest cultivation and the development and utilization of bamboo culm fiber.

Mature Tubers of Cyperus rotundus Confer Flooding Tolerance by Adopting A “Low-oxygen Quiescence Strategy”, which may Contribute to Its Emergence in Rice Fields

Abstract Purple nutsedge (Cyperus rotundus L.) is one of the world’s resilient upland weeds, primarily spreading through its tubers. Its emergence in rice fields has been increasing, likely due to changing paddy farming practices. This study aimed to investigate how C. rotundus, an upland weed, can withstand soil flooding and become a problematic weed in rice (Oryza sativa L.) fields. The first comparative analysis focused on the survival and recovery characteristics of growing and mature tubers of C. rotundus exposed to soil flooding conditions. Notably, mature tubers exhibited significant survival and recovery abilities in these environments. Based on this observation, further investigation was carried out to explore the morphological structure, non-structural carbohydrates, and respiratory mechanisms of mature tubers in response to prolonged soil flooding. Over time, the mature tubers did not form aerenchyma but instead gradually accumulated lignified sclerenchyma fibers, with lignin content also increasing. After 90 days, the lignified sclerenchyma fibers and lignin contents were 4.0 and 1.1 times higher than those in no soil flooding (CK). Concurrently, soluble sugar content decreased while starch content increased, providing energy storage, and alcohol dehydrogenase (ADH) activity rose to support anaerobic respiration via alcohol fermentation. These results indicated that mature tubers survived in soil flooding conditions by adopting a “low-oxygen quiescence strategy”, which involves morphological adaptations through the development of lignified sclerenchyma fibers, increased starch reserves for energy storage, and enhanced anaerobic respiration. This mechanism likely underpins the flooding tolerance of mature C. rotundus tubers, allowing them to endure unfavorable conditions and subsequently germinate and grow once flooding subsides. This study provides a preliminary explanation of the mechanism by which mature tubers of C. rotundus from the upland areas confer flooding tolerance, shedding light on the reasons behind this weed’s increasing presence in rice fields.

A review on recent trends in smart textiles

Recent advancements in both domestic and international research have considerably enhanced the development of smart fibers and smart textile, which are now being increasingly integrated into the textile industry. Advanced textiles encompass five primary functions; sensors, data processing, actuators, storage and communication. These technologies must be effectively integrated into clothing, ensuring they meet essential requirements like comfort, durability, and resilience to routine maintenance. Designers engaged with traditional textiles might address challenges by integrating smart materials and re-evaluating their design methodologies to leverage the distinctive properties of these advanced materials. This review examines recent developments in Smart Textiles, emphasizing the materials and their recent trends.

From Fiber Layout to the Sensor: Preparation Methods as Key Factors for High-Quality Coupled-Core-Fiber Sensors.

During recent years, the optical-fiber-based simultaneous sensing of strain and temperature has attracted increased interest for different applications, e.g., in medicine, architecture, and aerospace. Specialized fiber layouts further enlarge the field of applications at much lower costs and with easier handling. Today, the performance of many sensors fabricated from conventional fibers suffers from cross-sensitivity (temperature and strain) and relatively high interrogation costs. In contrast, customized fiber architectures would make it possible to circumvent such sensor drawbacks. Here, we report on the development of a high-quality coupled-core fiber and its performance for sensors-from the initial fiber layout via elaboration of the preform and fiber up to the sensor evaluation. A compact, high-speed, and cost-effective interrogation unit using such a specialized coupled-core fiber has been designed to monitor reflectivity changes while even being able to distinguish the direction of the force or impact. Several fiber core material techniques and approaches were investigated, which made it possible to obtain a sufficient volume of material for the required fiber core number and a specialized fiber core geometry in terms of core distances and radial refractive index profile, whilst handling the non-symmetrical fiber architectures of such modeled, complex structures and balancing resources and efforts.

Agave schidigera Transcriptome Reveals Stress-Responsive Phenylalanine ammonia-lyase Genes in Agave

Agave is a significant fiber crop in tropical regions, known for its high fiber strength. Lignin is closely associated with fiber strength, and phenylalanine ammonia-lyase (PAL) serves as the initial enzyme in biosynthesis of lignin. Hence, it is of considerable significance to study the genes of PAL family to analyze the characteristics and mechanism of sisal fiber development. In this research, we conducted a transcriptomic analysis of Agave schidigera, a widely recognized ornamental plant in agave. Approximately 29.85 million clean reads were acquired through Illumina sequencing. In total, 116,602 transcripts including 72,160 unigenes were assembled, and 22.06~63.56% of those unigenes were annotated in public databases. Two, six, six and six PAL genes were successfully identified and cloned from A. schidigera, A. deserti, A. tequilana and A. H11648, respectively. After phylogenetic analysis, these genes were clustered into two branches. Genes AhPLA2a and AhPLA2c exhibited higher expression levels compared to other genes but had different expression patterns. Moreover, AhPLA2a and AhPLA2c were expressed at high levels under full-nutrient, nitrogen-free and phosphorus-free stresses. Most PAL genes were induced by Phytophthora nicotianae Breda, especially AhPAL1a, AhPAL1b, AhPAL2b and AhPAL2c. This research is the first work to present a de novo transcriptome dataset for A. schidigera, enriching its bioinformation of transcripts. The cloned PAL genes and the expression analyses will form the basis of future research on lignin biosynthesis, the relationship between lignin and fiber strength, and stress resistance in Agave species.

Carbon fibers decorated with TiO2 nanoparticles for photocatalytic degradation of methylene blue dye

This report demonstrates the development of carbon fibers (CFs) decorated with TiO2 nanoparticles (NPs) as an efficient photocatalyst for the photocatalytic degradation of methylene blue (MB) as a model dye. Carbon fibers were produced by carbonization of polyacrylonitrile fibers, previously produced by centrifugal spinning. Subsequently, the CFs were decorated with TiO2 NPs (CFs@TiO2) by tailored soaking protocol using aqueous TiCl4 solution with different concentrations (0.025, 0.05, 0.1, and 0.2 M). SEM analyses revealed that soaking in TiCl4 produced a smooth, conformal, continuous TiO2 nanoparticulate coating with thickness increasing from 40.4 ± 21.2 to 257.9 ± 63.9 nm with increasing TiCl4 concentration. X-ray diffraction and Raman spectroscopy confirmed the anatase nature of TiO2. Photocatalytic decomposition rates of MB were assessed under UV light illumination for all CFs@TiO2 samples, and it was revealed that the lowest amount of TiO2 NP on C yielded the highest rates. The synergistic interaction between CFs and TiO2 NPs with a uniform morphology and a well-crystalline anatase structure, present in an optimal amount of fiber bodies, is the key reason for the remarkable photocatalytic performance. This work shows that C fibers decorated with an optimal amount of TiO2 NPs have a great potential as an effective photocatalytic material.

Daily glycome and transcriptome profiling reveals polysaccharide structures and correlated glycosyltransferases critical for cotton fiber growth.

Cotton fiber is the most valuable naturally available material for the textile industry and the fiber length and strength are key determinants of its quality. Dynamic changes in the pectin, xyloglucan, xylan, and cellulose polysaccharide epitope content during fiber growth contribute to complex remodeling of fiber cell wall (CW) and quality. Detailed knowledge about polysaccharide compositional and structural alteration in the fiber during fiber elongation and strengthening is important to understand the molecular dynamics of fiber development and improve its quality. Here, large-scale glycome profiling coupled with fiber phenotype and transcriptome profiling was conducted on fiber collected daily covering the most critical window of fiber development. The profiling studies with high temporal resolution allowed us to identify specific polysaccharide epitopes associated with distinct fiber phenotypes that might contribute to fiber quality. This study revealed the critical role of highly branched RG-I pectin epitopes such as β-1,4-linked-galactans, β-1,6-linked-galactans, and arabinogalactans, in addition to earlier reported homogalacturonans and xyloglucans in the formation of cotton fiber middle lamella and contributing to fiber plasticity and elongation. We also propose the essential role of heteroxylans (Xyl-MeGlcA and Xyl-3Ar), as a guiding factor for secondary CW cellulose microfibril arrangement, thus contributing to fiber strength. Correlation analysis of profiles of polysaccharide epitopes from glycome data and expression profiles of glycosyltransferase-encoding genes from transcriptome data identified several key putative glycosyltransferases that are potentially involved in synthesizing the critical polysaccharide epitopes. The findings of this study provide a foundation to identify molecular factors that dictate important fiber traits.

Downregulation of the GhROD1 Gene Improves Cotton Fiber Fineness by Decreasing Acyl Pool Saturation, Stimulating Small Heat Shock Proteins (sHSPs), and Reducing H2O2 Production.

Cotton fiber is one of the most important natural fiber sources in the world, and lipid metabolism plays a critical role in its development. However, the specific role of lipid molecules in fiber development and the impact of fatty acid alterations on fiber quality remain largely unknown. In this study, we demonstrate that the downregulation of GhROD1, a gene encoding phosphatidylcholine diacylglycerol cholinephosphotransferase (PDCT), results in an improvement of fiber fineness. We found that GhROD1 downregulation significantly increases the proportion of linoleic acid (18:2) in cotton fibers, which subsequently upregulates genes encoding small heat shock proteins (sHSPs). This, in turn, reduces H2O2 production, thus delaying secondary wall deposition and leading to finer fibers. Our findings reveal how alterations in linoleic acid influence cellulose synthesis and suggest a potential strategy to improve cotton fiber quality by regulating lipid metabolism pathways.

Population-wide DNA methylation polymorphisms at single-nucleotide resolution in 207 cotton accessions reveal epigenomic contributions to complex traits.

DNA methylation plays multiple regulatory roles in crop development. However, the relationships of methylation polymorphisms with genetic polymorphisms, gene expression, and phenotypic variation in natural crop populations remain largely unknown. Here, we surveyed high-quality methylomes, transcriptomes, and genomes obtained from the 20-days-post-anthesis (DPA) cotton fibers of 207 accessions and extended the classical framework of population genetics to epigenetics. Over 287 million single methylation polymorphisms (SMPs) were identified, 100 times more than the number of single nucleotide polymorphisms (SNPs). These SMPs were significantly enriched in intragenic regions while depleted in transposable elements. Association analysis further identified a total of 5,426,782 cis-methylation quantitative trait loci (cis-meQTLs), 5078 cis-expression quantitative trait methylation (cis-eQTMs), and 9157 expression quantitative trait loci (eQTLs). Notably, 36.39% of cis-eQTM genes were not associated with genetic variation, indicating that a large number of SMPs associated with gene expression variation are independent of SNPs. In addition, out of the 1715 epigenetic loci associated with yield and fiber quality traits, only 36 (2.10%) were shared with genome-wide association study (GWAS) loci. The construction of multi-omics regulatory networks revealed 43 cis-eQTM genes potentially involved in fiber development, which cannot be identified by GWAS alone. Among these genes, the role of one encoding CBL-interacting protein kinase 10 in fiber length regulation was successfully validated through gene editing. Taken together, our findings prove that DNA methylation data can serve as an additional resource for breeding purposes and can offer opportunities to enhance and expedite the crop improvement process.

Interaction of the cyclin-dependent kinase inhibitor GhKRP6 with RING-Type E3 ligase influences the fiber length in Upland cotton

Upland cotton (Gossypium hirsutum L.) is the major crop producing renewable fiber for textiles. Cotton fiber length is an economically important trait that affects the quality of the yarn. The Upland cotton multi-parent advanced generation intercross (MAGIC) population was developed for genetics research to understand how fiber traits can be improved without reducing fiber yield. A genome-wide association study of the MAGIC population identified a significant fiber length QTL on Chromosome D11 (qFL-D11–1). To understand how the qFL-D11–1 regulates fiber length, we developed F5 lines by crossing the longest and the shortest fiber recombinant inbred lines (RILs) of the MAGIC population to establish lines with parental haplotypes at the qFL-D11–1 but segregating for other loci. The F5 lines and parental RILs were sequenced to detect exchanges from parents' genomic regions in the progeny. One segregating genomic region in the F5 lines coincided with qFL-D12–1, which additively affected fiber length. Correlation analysis of the expression patterns of genes from the two QTLs with the fiber lengths in the MAGIC population showed the highest correlation of the RING-type ubiquitin E3 ligase (GhUbE3) from qFL-D12–1. Kip-related protein-6 (KRP6) is the candidate gene from the qFL-D11–1. A yeast two-hybrid and bimolecular fluorescence complementation assays demonstrated a physical interaction between GhKRP6 (Ghir_D11G020340) and GhUbE3 (Ghir_D12G006080). RNAseq showed that the GhUbE3 expression is reciprocal to the interacting GhKRP6 during fiber development. Virus-induced gene silencing (VIGS) of GhKRP6 increased fiber length. The data indicates that GhUbE3 controls the dose of GhKRP6's inhibitory activity and, therefore, the duration of fiber elongation.

A Genome-Wide Alternative Splicing Analysis of Gossypium arboreum and Gossypium raimondii During Fiber Development

Alternative splicing (AS) is a crucial post-transcriptional regulatory mechanism that contributes to proteome complexity and versatility in different plant species. However, detailed AS exploration in diploid cotton during fiber development has not been reported. In this study, we comparatively analyzed G. arboreum and G. raimondii AS events during fiber development using transcriptome data and identified 9690 and 7617 AS events that were distributed in 6483 and 4859 genes, respectively. G. arboreum had more AS genes and AS events than G. raimondii, and most AS genes were distributed at both ends of all 13 chromosomes in both diploid cotton species. Four major AS types, including IR, SE, A3SS, and A5SS, were all experimentally validated through RT-PCR assays. G. arboreum and G. raimondii had only 1888 AS genes in common, accounting for one-third and one-half of the total number of AS genes, respectively. Furthermore, we found a lysine-specific demethylase coding gene with a different AS mechanism in G. arboreum and G. raimondii, in which AS isoforms lacked part of a key conserved domain. Our findings may provide new directions for the discovery of functional genes involved in cotton species differentiation.