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Cotton architecture is partly determined by shoot branching and flowering patterns. GhBRC1 was previously identified by RNA-seq analysis of nulliplex-branching and normal-branching cotton. However, the roles of GhBRC1 in cotton remain unclear. In the present study, investigations of nuclear localization and transcriptional activity indicated that GhBRC1 has characteristics typical of transcription factors. Gene expression analysis showed that GhBRC1 was highly expressed in axillary buds but displayed different expression patterns between the two branching types. Overexpression of GhBRC1 in Arabidopsis significantly inhibited the number of branches and promoted flowering. In contrast, silencing GhBRC1 in cotton significantly promoted seedling growth. GhBRC1 was induced by multiple hormones, including strigolactones, which promoted seedling growth and seed germination of Arabidopsis plants overexpressing GhBRC1. Consistent with these findings, RNA-seq analysis of virus-induced gene silencing treated cotton revealed that a large number of genes were differentially expressed between GhBRC1-silenced and control plants, and these genes were significantly enriched in plant hormone signalling pathways. Together, our data indicates that GhBRC1 regulates plant branching and flowering through multiple regulatory pathways, especially those regulating plant hormones, with functions partly differing from those of Arabidopsis BRC1. These results provide insights into the molecular mechanisms controlling plant architecture, which is important for breeding cotton with ideal plant architecture and high yield.

Upland cotton is an important allotetraploid crop that provides both natural fiber for the textile industry and edible vegetable oil for the food or feed industry. To better understand the genetic mechanism that regulates the biosynthesis of storage oil in cottonseed, we identified the genes harbored in the major quantitative trait loci/nucleotides (QTLs/QTNs) of kernel oil content (KOC) in cottonseed via both multiple linkage analyses and genome-wide association studies (GWAS). In 'CCRI70' RILs, six stable QTLs were simultaneously identified by linkage analysis of CHIP and SLAF-seq strategies. In '0-153' RILs, eight stable QTLs were detected by consensus linkage analysis integrating multiple strategies. In the natural panel, thirteen and eight loci were associated across multiple environments with two algorithms of GWAS. Within the confidence interval of a major common QTL on chromosome 3, six genes were identified as participating in the interaction network highly correlated with cottonseed KOC. Further observations of gene differential expression showed that four of the genes

The present study demonstrated a de novo correlation among fiber quality genes in multiple RIL populations including sGK9708 × 0–153, LMY22 × LY343 and Lumianyan28 × Xinluzao24. The current study was conducted to identify the major common QTLs including fiber length and strength, and to identify the co-expression networks of fiber length and strength QTLs harbored genes to target the hub genes. The RNA-seq data of sGK9708 × 0–153 population highlighted 50 and 48 candidate genes of fiber length and fiber strength QTLs. A total of 29 and 21 hub genes were identified in fiber length and strength co-expression network modules. The absolute values of correlation coefficient close to 1 resulted highly positive correlation among hub genes. Results also suggested that the gene correlation significantly influence the gene expression at different fiber development stages. These results might provide useful reference for further experiments in multiple RIL populations and suggest potential candidate genes for functional studies in cotton.

GATA transcription factors (TFs), which bind to DNA in regulatory regions, are involved in cell differentiation and possess a type-IV zinc finger and a DNA-binding domain. GATA genes have been characterized in plant species such as Arabidopsis thaliana, Oryza sativa, and Glycine max, and their functions have been elucidated in A. thaliana. Although many Gossypium quantitative trait loci for fiber quality harbor GATA TFs, GATA genes have not yet been characterized in cotton. In this study, we identified 179 GATA genes from the genomes of three Gossypium species. We analyzed the phylogenetic relationships, chromosomal distribution, gene structure, expression pattern, and predicted promoters of all 179 Gossypium GATA genes (46 in G. raimondii, 46 in G. arboreum, and 87 in G. hirsutum). Phylogenetic analysis grouped the 179 GATA genes into four subfamilies. Domain analysis revealed that GATA domains in subfamilies I, II, and III were located near the C-terminal, whereas those in subfamily IV were adjacent to the N-terminal. RNA-seq and (Real-time PCR) qRT-PCR revealed that 39.1% (34/87) of GATA genes were expressed in growing plant tissues in G. hirsutum, but only 12.6% (11/87) were expressed during fiber development. In addition, 45.7% (21/46) and 26.1% (12/46) of GATA genes were expressed in G. arboreum and G. raimondii, respectively. Our results may be useful for elucidating the evolution, expression patterns, and functional divergence of GATA genes in Gossypium.

In-situ WC grains were synthesized by using in-situ metallurgical reaction in W-Fe-Ni-C alloys system. The growth mechanisms as well as the coarsening process of WC grains were analyzed by XRD, SEM and ab initio calculation. Results show that the morphology evolution of in-situ WC growth unit evolves from sphere-like→icosahedron→octahedron→truncated-octahedron→flat-tri-prism. The final flat-tri-prism is bound by two basal facets {001} and three prismatic facets { 1 ¯ 10}. In short, the growth process of in-situ WC grain includes two independent stages, one is the formation of WC growth unit on basal facets {001}, and the other is the lateral stack of WC growth units in facets {001} as well as the vertical stack of WC growth units along 〈001〉 direction. Finally the in-situ WC grain grows into multi-layered triangular prism. The coarsening of in-situ WC grains, known as the Ostwald ripening, is partly due to the prior formed WC grains basal facets { 1 ¯ 10} can act as the heterogeneous nucleus of other newly generated WC grains hence promoting the forming of in-situ WC nucleus. The excellent mechanical properties, such as high hardness and good toughness, of WC grain benefit from its growth characteristics.

In-situ synthesis of WC/Fe-30Ni ceramic metal coating (CMC) by plasma transferred arc metallurgical reaction (PTAMR) with raw materials W, C and Fe-30 wt% Ni were investigated. The in-situ metallurgical reaction was investigated by thermodynamic calculation and X-ray diffractometry (XRD). The in-situ WC grain size, grain growth characteristic and microstructures were analyzed by scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS). The mechanical properties such as hardness, toughness and wear resistance were tested. Results show that the morphology of in-situ WC grain is triangular prism which is a multi-layered crystal structure with high hardness, good toughness and high wear resistance. The excellent mechanical behaviors of in-situ WC are decided by its growth mechanism. Increasing the contents of in-situ WC will directly increase the wear resistance of WC/Fe-30Ni coating.

In order to improve the dry sliding tribology properties of mild steel compound, the in-situ WC carbide coatings with 18, 32, 54 vol% WC were successfully synthesized using plasma transferred arc metallurgic reaction (PTAMR) with alloy powders W, C and Fe-30Ni. The composition, microstructure and microhardness of the carbide coatings were characterized. It was found that the carbide coating consisted of WC, M 6 C and γ phases, carbides distribute gradually from the coating bottom to top, the in-situ WC crystal grows into triangle prism structure with high hardness and good toughness. Dry sliding tribology behaviors were studied on block-on-wheel dry sliding wear tester with load 300 N, sliding speed 0.836 m/s and distance 500 m. Results show that the friction coefficient diagrams contain three stages, variation of friction coefficient increase with the content of WC, friction temperature increase with the sliding distance, increasing the content of WC can directly increase the antiwear property of WC/Fe carbide coating. The main wear mechanisms of in-situ WC/Fe carbide coating are adhesive, oxidation, micro-cutting and ploughing wear.

n-SiCp/AZ91D magnesium matrix nanocomposites show the high strength and relatively good plasticity after T6 ageing treatment. In this study, optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to study the interaction of nanoparticles and dislocations with β-Mg17Al12 precipitates in n-SiCp/AZ91D-T6 nanocomposites. The experimental results show that SiC nanoparticles have a certain influence on the morphology, size and distribution of β-Mg17Al12 precipitates, which make the precipitates finer and more disperse, thus giving full play to the precipitation strengthening effect of the secondary precipitation phases. A large number of dislocations occur around the nanoparticles and the precipitates in the plastic deformation process. The dislocations tangle around the precipitates when the dislocations with different orientations encounter, and some dislocations leave the dislocation sinks after cutting through the Mg/Mg17Al12 interfaces. Refinement of matrix and precipitate phase grains, entanglement of dislocations and formation of dislocation sinks are the main reasons for the high strength and good plasticity of n-SiCp/AZ91D nanocomposites after T6 ageing treatment.

1.0 wt% MWCNTs/AZ91D magnesium matrix nanocomposites were prepared by metal mold gravity casting process assisted by high-intensity ultrasonic dispersion, and the ductility was further improved by T4 solid solution treatment. The tensile test results at room temperature revealed that the tensile strength and elongation of 1.0 wt% MWCNTs/AZ91D nanocomposites after T4 solid solution treatment reached up to 281.7 MPa and 15.4%, respectively. The ductility of magnesium matrix nanocomposites was significantly improved by the addition of Multiwalled carbon nanotubes (MWCNTs) and T4 solid solution treatment. SEM and TEM were used to observe the microstructure of 1.0 wt% MWCNTs/AZ91D-T4 nanocomposites after the tensile plastic deformation at room temperature. A considerable number of slip bands and twins were found in the microstructure of the nanocomposites. High strain zones were formed around MWCNTs during the tensile process at room temperature. A large number of dislocations and stacking faults were generated in the high strain zones, which could be used as the origin of slip bands and twins, so MWCNTs can promote slip and twining. MWCNTs can further activate non-basal slip and cross slip, and improve the ductility of 1.0 wt% MWCNTs/AZ91D-T4 nanocomposites.

Cotton is an important fiber plant, and it's attractive to elucidate the molecular mechanism of anther development due to the close relationship between the anther fertility and boll-setting, and also fiber yield. In the present paper, 47.2 million paired-end reads with average length of 82.87 bp from the anthers of TM-1 (Gossypium hirsutum L.), a genetic standard line, were generated through transcriptome sequencing, and 210,965 unigenes of more than 100 bp were obtained. BLAST, KEGG, COG, and GO analyses showed that the genes were enriched in the processes of transcription, translation, and post-translation as well as hormone signal transduction, the transcription factor families, and cell wall-related genes mainly participating in cell expansion and carbohydrate metabolism. Further analysis identified 11,153 potential SSRs. A suit of 5122 primer pair sequences were designed, and 82 of 300 randomly selected primer pairs produced reproducible amplicons that were polymorphic among 22 cotton accessions from G. hirsutum, Gossypium barbadense and Gossypium arboreum. The UPGMA clustering analysis further confirmed high quality and effectiveness of these novel SSR markers. The present study provided insights into the transcriptome profile of the cotton and established a public information platform for functional genomics and molecular breeding.

In this paper, three distinct sizes of rod carbide (Cr,Fe)7C3 (20.9, 35.2 and 66.3 μm) were in-situ synthesized in the composite coatings using three mass ratios of Cr3C2/Fe–CrNiBSi (1:5, 3:5 and 5:5) powder blends via plasma transferred arc (PTA) welding. The present investigations evaluate the effects of rod carbide sizes, contents, loading and sliding distance on the friction and wear behaviors of (Cr,Fe)7C3-reinforced α-Fe composite coating as sliding against hard alloy AISI W1-1.0C on a block-on-wheel dry sliding wear tester. The focuses are given on the friction coefficient (FC) and wear rate (WR) as function of parameters such as sliding distances (210–1260 m) and normal loads (100–300 N). It was found that the size and content of rod carbide (Cr,Fe)7C3 increase with the mass ratio of Cr3C2, by which the hardness and wear resistance of the coatings were improved. The stability of FC increases with the content of rod carbide (Cr,Fe)7C3 as the load increased from 100 to 300 N. The coatings' worn surfaces were examined and analyzed by using SEM and EDS. It was found that the main wear mechanisms of the coatings vary with the applied normal loads. Cracks nucleated and propagated on the worn surfaces of (Cr,Fe)7C3 rods as the loads increased from 100 to 300 N. The micro-mechanisms of crack formation were analyzed.

This paper presents a new type of FeNi matrix composite coating reinforced with multi-scale carbides WC-TiC fabricated by in-situ synthesis method PTAMR (plasma transferred arc metallurgical reaction). The microstructures, phases, hardness, and tribology properties of the composite coating were analyzed. Results show that the multi-scale carbides WC-TiC with fine intact shape were successfully in-situ synthesized in the matrix. Owing to the in-situ synthesis method, plenty of TiC tiny carbides in-situ grow in both the carbide WC and matrix, known as the precipitation hardening, by which the hardness of carbide WC and matrix are increased from 1497 to 1682 HV4.9 and 411 to 731 HV4.9 respectively. The analysis of crystallographic relationship shows that the lattice misfit between 10 1 ¯ 0 WC and (001)TiC is 6.26%, indicating carbides WC and TiC can act as mutual effective heterogeneous nuclei and promote each other. Benefit from the in-situ WC-TiC multi-scale carbides hybrid growth characteristic, the wear resistance, and frictional stability are all increased in compared with the coating reinforced with in-situ single-carbide WC.

The preparation, morphologies, and properties of Fe3O4 octahedra have attracted considerable attention, while their formation mechanism has been less investigated. In this study, Fe3O4 nano- and microoctahedra are prepared by dealloying Al–xFe (x = 5–25 at.%) alloys in NaOH aqueous solutions with different concentrations. The dealloying of Al 15Fe in the 5-mol·L−1 NaOH solution provides the most regular Fe3O4 octahedra. Al13Fe4 in the precursor Al Fe alloy and appropriate concentration of OH– ions are dominant factors in the formation of Fe3O4 octahedra by changing the chemical potentials and growth rates along the 〈111〉 and 〈100〉 plane directions. A low concentration of NaOH solution deteriorates the anisotropic growth of Fe3O4, while a highly concentrated solution enhances the reduction of oxides and produces α-Fe rather than Fe3O4. In addition to the experimental results, ab-initio molecular dynamics simulations are performed to reveal the evolutions of the surface energies and growth rates of different facets, depicting the formation trajectory from Fe3O4 nuclei to octahedra. This fundamental understanding provides technological guidelines for the synthesis and morphology control of Fe3O4, being of significance in the development of functional nanoparticles.

The nucleation of carbide (Cr, Fe) 7 C 3 on the Cr 3 C 2 particle in the Cr 3 C 2 /Fe-CrNiBSi composite coating was studied. It was found that there were a great deal of craters on the surface of half-dissolved Cr 3 C 2 particle, and plenty of carbide (Cr, Fe) 7 C 3 buds nucleated and grown out there. The analysis of crystallographic relationship shows that the lattice misfit between 013 Cr 3 C 2 and 10 1 − 0 Cr Fe 7 C 3 is 8.66%, indicating Cr 3 C 2 can efficiently act as the heterogeneous nuclei of (Cr, Fe) 7 C 3 . The thermodynamic analysis indicates that the Cr 3 C 2 surface craters can promote forming (Cr, Fe) 7 C 3 nucleus, and the size of (Cr, Fe) 7 C 3 buds grow on the craters was influenced by the shape factor x = R / r c ( R : crater concave radius and r c : critical (Cr, Fe) 7 C 3 nucleus radius) and the contact angle θ between (Cr, Fe) 7 C 3 embryo and Cr 3 C 2 crater surface.