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Deciphering the genetic basis of organoleptic traits is critical for improving the quality of fruits, which greatly shapes their appeal to consumers. Here, we characterize the citrus R3-MYB transcription factor TRIPTYCHON-LIKE (CitTRL), which is closely associated with the levels of citric acid, proanthocyanidins (PAs), and anthocyanins. Overexpression of CitTRL lowered acidity levels and PA contents in citrus calli as well as anthocyanin and PA contents in Arabidopsis leaves and seeds. CitTRL interacts with the two basic helix–loop–helix (bHLH) proteins CitbHLH1 and ANTHOCYANIN 1 (CitAN1) to regulate fruit quality. We show that CitTRL competes with the R2R3-MYB CitRuby1 for binding to CitbHLH1 or CitAN1, thereby repressing their activation of anthocyanin structural genes. CitTRL also competes with a second R2R3-MYB, CitPH4, for binding to CitAN1, thus altering the expression of the vacuolar proton-pump gene PH5 and Leucoanthocyanidin reductase , responsible for vacuolar acidification and proanthocyanidins biosynthesis, respectively. Moreover, CitPH4 activates CitTRL transcription, thus forming an activator–repressor loop to prevent the overaccumulation of citric acid and PAs. Overall, this study demonstrates that CitTRL acts as a repressor of the accumulation of citric acid, PAs, and anthocyanins by a cross-regulation mechanism. Our results provide an opportunity to simultaneously manipulate these key traits as a means to produce citrus fruits that are both visually and organoleptically appealing. [ABSTRACT FROM AUTHOR]

The fracture toughness of pressure pipe steels is vital for their design and safe operation. Understanding the deterioration of the fracture toughness and the corresponding fracture mechanisms is instructive and meaningful for material selection and development. The elastic–plastic fracture toughness of 9% Cr steels aged at 873 K and 923 K from the initial state to 20000 h was investigated at ambient temperature and 873 K. The deterioration of the fracture toughness and the corresponding fracture mechanisms are discussed in detail. For 9% Cr steels, voids mainly initiated from primary inclusions such as silicides, sulfides, alumina and manganides in as-received state, while voids initiated from both primary inclusions and secondary particles such as the Laves phase after long-term aging. These voids grew and coalesced with neighboring voids and crack tips subsequently until ultimately fracture. After aging at 873 K, the fracture toughness values tested at 873 K decreased from the initial state to 3000 h and then increased to 10000 h. The peculiar deterioration of the fracture properties after 3000 h of aging at 873 K can be attributed to the high number density of Laves phase particles in the steels. It was found that the densely distributed hard Laves phase particles induced strain concentration at the interface between the Laves phase and the matrix under plane-strain tension condition and promoted nucleation of voids. It was suggested that the spatial distribution of the Laves phase played a significant role on the void formation. 9% Cr steels with a denser distribution of Laves phases brings about voids with shorter interspaces, which are more susceptible to coalesce into crack tip, resulting in lower fracture resistance. After aging at 923 K from 10000 h to 20000 h, the number density, size and volume fraction of precipitates, block size, misorientation angle and dislocation density remained almost constant. The slight increase in the fracture toughness from 10000 h to 20000 h can be mainly ascribed to the coarsening of the martensite lath in this stage. [ABSTRACT FROM AUTHOR]

Background: Citrus fruits are consumed freshly or as juice to directly provide various dietary flavonoids to humans. Diverse metabolites are present among Citrus genera, and many flavonoids biosynthetic genes were induced after abiotic stresses. To better understand the underlying mechanism, we designed experiments to overexpress a UDP-GLUCOSYL TRANSFERASE gene from sweet orange (Citrus sinensis) to evaluate its possible function in metabolism and response to stress. Results: Our results demonstrated that overexpression of Cs-UGT78D3 resulted in high accumulation of proanthocyanidins in the seed coat and a dark brown color to transgenic Arabidopsis seeds. In addition, the total contents of flavonoid and anthocyanin were significantly enhanced in the leaves of overexpressed lines. Gene expression analyses indicated that many flavonoid (flavonol) and anthocyanin genes were up-regulated by 4–15 folds in transgenic Arabidopsis. Moreover, after 14 days of high light stress, the transgenic Arabidopsis lines showed strong antioxidant activity and higher total contents of anthocyanins and flavonoids in leaves compared with the wild type. Conclusion: Our study concluded that the citrus Cs-UGT78D3 gene contributes to proanthocyanidins accumulation in seed coats and confers tolerance to high light stress by accumulating the total anthocyanin and flavonoid contents with better antioxidant potential (due to photoprotective activity of anthocyanin) in the transgenic Arabidopsis. [ABSTRACT FROM AUTHOR]

The coupling effects between MX carbonitrides, M 2 X phase, M 23 C 6 carbides, and the Laves phase and their influences on the mechanical properties during long-term aging at 650 °C were studied. Before aging for 40500 h, the subgrain size is mainly stabilized by M 23 C 6 carbides, whose pinning effect gradually weakens with the coarsening during long-term aging. However, after aging for 40500 h, the volume fraction of nano-sized MX carbonitrides gradually increases and compensates for the loss of pinning effect from M 23 C 6 carbides, working together with the M 23 C 6 carbides to hinder the coarsening of the subgrain. The increase in the volume fraction of nano-sized MX carbonitrides from 40500 h to 49500 h, mainly resulting from the gradual dissolution of M 2 (C,N) carbonitrides, which not only contributes to the stability of the strength through the pinning effect and precipitation strengthening, but also benefits the ductility by suppressing the rapid coarsening of the Laves phase through the strong competition for Si between the Laves phase and MX. An unusual combination of stable strength and stable ductility in the later stages of long-term aging at 650 °C (approximately 9000 h) was achieved. Image 1 [ABSTRACT FROM AUTHOR]

Abstract NiAl-type nanoparticles retained on phase interfaces in the first step of partitioning treatment, e.g. 610 and 630 °C/1 h (P 610 and P 630), could effectively hinder interface migration from austenite to ferrite during the subsequent tempering treatment (500 °C/2 h) due to pinning effect. The deduced pinning pressure from the dilatation results is consistent with that from the pinning theory calculation. When the nanoparticles were absent in the specimen treated at 650 °C/1 h (P 650), the significant interface migration persisted before precipitation of NiAl-type nanoparticles (500 °C/1800s) and gradually disappeared after they precipitated (500 °C/3600 s), which confirmed that nanoprecipitation does suppress ferrite transformation by the pinning effect. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

The evolution of the microstructure and its effect on mechanical properties of a 10% Cr steel under long-term aging at 650 °C have been investigated. During short-term aging (<6000h), the reduction of room temperature hardness and yield strength are mainly caused by the decline of dislocation density. However, under long-term aging (from 6000h to 38200h), they are directly attributed to the coarsening of subgrains. The coarsening kinetics of Laves phase (≥18000h), M 23 C 6 carbides and MX carbonitrides are well consistent with the ripening model in multicomponent alloys. Before 18000h, the coarsening of Laves phase is strongly affected by the swallowing growth mechanism. The plasticity in terms of fracture elongation at room temperature shows a non-monotonic dependence on the aging time, the effect factors such as dislocation density, strain level and distribution, subgrain width, precipitates size and ratio of brittle phase interfaces have been studied in detail. During tensile deformation, the large and irregular Laves phase particles induce severe strain localization and tend to form large strain concentration block. It is found that deterioration of plasticity is dominated by severely inhomogeneous and large size of Laves phase caused by two different nucleation and growth mechanisms and high coarsening rate (∼32.0 n m / h 1 / 3 ), rather than the increase in the ratio of brittle phase interfaces. The swallowing growth mechanism for Laves phase, growing by swallowing the adjacent M 23 C 6 carbides, has been emphatically discussed. [ABSTRACT FROM AUTHOR]

Recently, the sulfate radical-based advanced oxidation processes (SR-AOPs) have been widely studied and shown great potential application in water treatment. Numerous studies affirm that the persulfate (PS) can be effectively activated by carbon-based materials (CBMs), transition metal-based materials (TMBMs), light, heat, etc., to produce various active species (e.g., SO 4 •−, •OH, 1O 2) and apply for pollutants removal. Among them, the carbon aerogel-based materials (CABMs) with three-dimensional (3D), low-density, and highly porous network structure have shown unique performance and advantages in PS activation for water treatment. In this review, the synthesis methods, types, and activation processes of CABMs in PS activation were comprehensively summarized and discussed first. Then, the unique properties (including structural, catalytic, and recyclable properties) of CABMs during PS activation were discussed. Besides, the effects of different operating conditions on the activation processes and the relative applications of the CABMs/PS systems in water treatment were also discussed. Lastly, the opportunities and challenges of CABMs in PS activation for water treatment were introduced and discussed. It is hoped that this review will motivate some novel inspirations for the in-depth study of this field. • Synthesis, classifications and activation processes of CABMs in PS activation were summarized. • Unique properties (i.e., structural, catalytic, and recyclable properties) of CABMs during PS activation were discussed. • Applications and influence factors of CABMs in PS activation for water treatment were summarized. • Future challenges of using CABMs to activate PS for water treatment were proposed. [ABSTRACT FROM AUTHOR]

The pursuit of strong and ductile Al alloys with superior resistance to hydrogen embrittlement (HE) is practically significant across the aerospace and transportation industries among others. Unfortunately, effective ways to progress on the strength-HE trade-off for Al-alloys remain elusive. A strategy of suppressing HE by introducing intermetallic compound (IMC) particles to achieve hydrogen redistribution in various trapping sites was proposed. Here, we systematically induce the precipitation of a constant volume fraction of intermetallic compound (IMC) particles by adding one of 14 elements in a ternary Al-Zn-Mg high-strength alloy. We show a strong correlation between hydrogen trapping energies of the IMC obtained from ab initio calculations with the resistance to HE. Mn-rich Al 11 Mn 3 Zn 2 particles exhibit the highest hydrogen trapping energy (0.859 eV/atom), leading to a decrease by approximately 5 orders of magnitude in the hydrogen occupancy in η 2 (MgZn 2) phase interfaces and grain boundaries, where HE cracks initiate. The Mn-addition did not deteriorate the ductility and most Al 11 Mn 3 Zn 2 particles remained intact during plastic deformation which was revealed by in-situ 3D X-ray tomography. Hydrogen-induced strain localization at η 2 phase interfaces and grain boundaries were inhibited due to strong hydrogen trapping capacity of Al 11 Mn 3 Zn 2 , hence preventing HE cracks initiation. Our approach effectively suppresses hydrogen-induced cracks without sacrificing the ductility, and our strategy can help the design roadmap of HE-tolerant high-strength metallic alloys. [Display omitted] [ABSTRACT FROM AUTHOR]

In the 10% Cr martensite ferritic steel, it is found that most of M 23 C 6 carbides appear on high angle boundaries (HABs) with a misorientation angle of 40°–60° and only a small amount of them precipitate at low angle boundaries (LABs) with a misorientation angle of 8°–15°. It has always been considered that V is added to mainly form MX carbides. However, in the present work, V will also diffuse into M 23 C 6 carbides after aged at 650 °C for 12,000 h, which not only replaces Fe but also W and Mo. From the initial state to 25,000 h, the variation of the mean size of M 23 C 6 basically obeys the Lifshitz–Slyozov–Wagner coarsening theory. When the V content in M 23 C 6 gradually increases from 12,000 h to 25,000 h, the coarsening rate of M 23 C 6 decreases remarkably. The V in M 23 C 6 plays an important role in controlling the coarsening of M 23 C 6 carbides in this stage. [ABSTRACT FROM AUTHOR]

The nucleation and growth of Laves phase in a 10% Cr martensite ferritic steel after long-term aging have been investigated in this paper. Laves phase, (Fe, Cr) 2 (Mo, W), was observed after long-term (>750 h) aging at 650 °C. It is found that Laves phases prefer to locate at prior austenite grain boundaries and martensite lath boundaries, especially, most of them precipitate at grain boundaries with a misorientation angle of 40–60° and only a small amount of them at 3–10°. Moreover, the size of Laves phase at 40–60° grain boundaries is larger than that at 3–10° grain boundaries. In addition, some Laves phases are formed in the regions adjacent to M 23 C 6 particles, with increasing aging time they will gradually swallow the Cr-rich M 23 C 6 carbides in close vicinity, resulting in carbon atoms segregation on the vicinity of phase interfaces between Laves phase and α-Fe. [ABSTRACT FROM AUTHOR]

High-temperature strength and microstructure stability in heat-resistant steels are the major concerns for their practical applications. A comprehensive understanding of the microstructure evolution and mechanical property degradation during creep exposure is of significant importance for safety operations. In this work, a series of interrupted creep tests of 9% Cr steels were conducted at 873 K and 160 MPa exposed to different creep durations. The gradual degradation of mechanical properties and microstructure evolution such as dislocation density, martensite lath, precipitates and grain boundary characteristics were studied. It was found that the high-temperature yield strength and micro-hardness significantly decreased from the initial state to 1000 h duration then kept relatively stable to 1500 h duration, and gradually declined until rupture. The degradation of mechanical properties in primary creep stage was mainly attributed to decline in dislocation density and coarsening of martensite lath. Coarsening of martensite lath, as well as precipitation strengthening played a significant role in secondary creep stage. In tertiary creep stage, synergistic effect of coarsening of martensite lath and precipitates and decline of dislocation density resulted in accelerated degradation of mechanical properties. The precipitation of Laves phase in early stage provided additional strengthening effect and compensated for the strength loss caused by the coarsening of martensite lath, contributing to the stability of mechanical properties from 1000 to 1500 h. Moreover, the growth of Laves phase induced insignificant stain concentration and ductility deterioration. Quantitative relationships between microstructure and mechanical properties were established and well-validated by experimental results. [ABSTRACT FROM AUTHOR]

A two-steps tempering-partitioning process is designed for redistributing carbon and austenite stabilizer such as manganese in a cold rolled medium-manganese steel. After tempering at 450℃ for 0.5h and 1h, a large number of metastable Mn-rich M 12 C carbides and high density of NiAl-type nanoparticles were found, and the segregation of carbon at the dislocations/interfaces around NiAl precipitates was revealed by 3D atom probe tomography (APT). The competition between the M 12 C carbides and the dislocations/interfaces for carbon inhibits transformation of the metastable M 12 C carbides to more stable carbides. During the following partitioning at 630℃ for 0.5h, the metastable Mn-rich M 12 C dissolved and the fine reversed austenite nucleating on the metastable M 12 C carbides exhibits a sharp gradient Mn distribution. The tailored metastable austenite inherited from metastable M 12 C carbide shows strong enrichment of Mn and C (Mn: 18.1 at.%, C: 1.56 at.%), dispersed distribution (9.8 μm−2) and fine size (50-200 nm). With the nature of both hard particle and transitionable phase, the austenite couples Orowan strengthening and transformation induced plasticity (TRIP) assisted work hardening. Outstanding dynamic mechanical properties (yield strength: 1350 MPa, total elongation: 30%) were achieved due to this microstructure. Here we report a strategy for the design of ultrahigh-strength steels by making metastable austenite serve as a strengthening second phase in addition to the TRIP effect. [ABSTRACT FROM AUTHOR]

ABSTRACT Dwarfing is a pivotal agronomic trait affecting both yield and quality. Citrus species exhibit substantial variation in plant height, among which internode length is a core element. However, the molecular mechanism governing internode elongation remains unclear. Here, we unveiled that the transcriptional cascade consisting of B‐BOX DOMAIN PROTEIN 22 (BBX22) and ELONGATED HYPOCOTYL 5 (HY5) finely tunes plant height and internode elongation in citrus. Loss‐of‐function mutations of BBX22 in an early‐flowering citrus (Citrus hindsii “SJG”) promoted internode elongation and reduced pigment accumulation, whereas ectopic expression of BBX22 in SJG, sweet orange (C. sinensis), pomelo (C. maxima) or heterologous expression of BBX22 in tomato (Solanum lycopersicum) significantly decreased internode length. Furthermore, exogenous application of gibberellin A3 (GA3) rescued the shortened internode and dwarf phenotype caused by BBX22 overexpression. Additional experiments revealed that BBX22 played a dual role in regulation internode elongation and pigmentation in citrus. On the one hand, it directly bound to and activated the expression of HY5, GA metabolism gene (GA2 OXIDASE 8, GA2ox8), carotenoid biosynthesis gene (PHYTOENE SYNTHASE 1, PSY1) and anthocyanin regulatory gene (Ruby1, a MYB DOMAIN PROTEIN). On the other hand, it acted as a cofactor of HY5, enhancing the ability of HY5 to regulate target genes expression. Together, our results reveal the critical role of the transcriptional cascade consisting of BBX22 and HY5 in controlling internode elongation and pigment accumulation in citrus. Unraveling the crosstalk regulatory mechanism between internode elongation and fruit pigmentation provides key genes for breeding of novel types with both dwarf and health‐beneficial fortification in citrus. [ABSTRACT FROM AUTHOR]

Apomixis, is an asexual mode of seed formation resulting in genetically identical or clonal seed with a maternal genotype. Apomixis has not been reported in seed crops where its flexible application in plant breeding could accelerate delivery of new varieties. By contrast, a sporophytic form of apomixis termed nucellar or adventitious embryony is common in the Rutaceae containing Citrus crop species. Here, multiple embryos develop from the maternal, somatic, nucellar cells of the ovule. They are incorporated into the enlarging embryo sac containing the sexually derived zygotic embryo and endosperm, which are products of double fertilization. Recent research has provided insights to the molecular basis for nucellar embryony. Here, we review the current understanding of the initiation, genetic basis and evolution of nucellar embryony in Citrus , and discuss prospects for future study and breeding applications of Citrus sporophytic apomixis. [ABSTRACT FROM AUTHOR]

Summary: Pummelo (Citrus maxima or Citrus grandis) is a basic species and an important type for breeding in Citrus. Pummelo is used not only for fresh consumption but also for medicinal purposes. However, the molecular basis of medicinal traits is unclear. Here, compared with wild citrus species/Citrus‐related genera, the content of 43 bioactive metabolites and their derivatives increased in the pummelo. Furthermore, we assembled the genome sequence of a variety for medicinal purposes with a long history, Citrus maxima 'Huazhouyou‐tomentosa' (HZY‐T), at the chromosome level with a genome size of 349.07 Mb. Comparative genomics showed that the expanded gene family in the pummelo genome was enriched in flavonoids‐, terpenoid‐, and phenylpropanoid biosynthesis. Using the metabolome and transcriptome of six developmental stages of HZY‐T and Citrus maxima 'Huazhouyou‐smooth' (HZY‐S) fruit peel, we generated the regulatory networks of bioactive metabolites and their derivatives. We identified a novel MYB transcription factor, CmtMYB108, as an important regulator of flavone pathways. Both mutations and expression of CmtMYB108, which targets the genes PAL (phenylalanine ammonia‐lyase) and FNS (flavone synthase), displayed differential expression between Citrus‐related genera, wild citrus species and pummelo species. This study provides insights into the evolution‐associated changes in bioactive metabolism during the origin process of pummelo. [ABSTRACT FROM AUTHOR]

(1) Background: the miR-301a is well known involving the proliferation and migration of tumor cells. However, the role of miR-301a in the migration and phagocytosis of macrophages is still unclear. (2) Methods: sciatic nerve injury, liver injury models, as well as primary macrophage cultures were prepared from the miR-301a knockout (KO) and wild type (WT) mice to assess the macrophage's migration and phagocytosis capabilities. Targetscan database analysis, Western blotting, siRNA transfection, and CXCR4 inhibition or activation were performed to reveal miR301a's potential mechanism. (3) Results: the macrophage's migration and phagocytosis were significantly attenuated by the miR-301a KO both in vivo and in vitro. MiR-301a can target Yin-Yang 1 (YY1), and miR-301a KO resulted in YY1 up-regulation and CXCR4 (YY1′s down-stream molecule) down-regulation. siYY1 increased the expression of CXCR4 and enhanced migration and phagocytosis in KO macrophages. Meanwhile, a CXCR4 inhibitor or agonist could attenuate or accelerate, respectively, the macrophage migration and phagocytosis. (4) Conclusions: current findings indicated that miR-301a plays important roles in a macrophage's capabilities of migration and phagocytosis through the YY1/CXCR4 pathway. Hence, miR-301a might be a promising therapeutic candidate for inflammatory diseases by adjusting macrophage bio-functions. [ABSTRACT FROM AUTHOR]

The effect of long-term thermal aging on microstructure and high-temperature strength of a 10% Cr martensite ferritic steel is investigated. Comparison of the long-term aging behavior at 700 °C with that at 650 °C reveals that the low angle boundary fraction increases and the coarsening of the M23C6 carbide accelerates at higher temperature, thereby the speed of subgrain growth increases. Additionally, elevated aging temperature suppressed nucleation of Laves phases and did not affect the K-S orientation relationship between M23C6 carbides and ferrite matrix. The yield strength at 700 °C decreases, obviously, with increase of aging time at 700 °C, but its decline trend is not fully consistent with the change of the dislocation density, which confirms that loss of high-temperature strength is not only due to decreasing of free dislocations. On the other hand, the variation on increasing of the subgrain width shows a similar abrupt trend to that on decreasing of the yield strength. It is suggested that for aged steel, subgrain coarsening is also an important factor for the deterioration of yield strength. [ABSTRACT FROM AUTHOR]

We directly captured, classified, and evaluated 3D particle debonding and fracture behavior in a H-charged 7075 Al alloy throughout the entire tensile deformation using synchrotron X-ray tomography and microstructural feature tracking techniques. The effects of particle size, shape, spatial clustering and stress state on strain-dependent particle damage were identified and isolated from each other. Moreover, state-of-the-art imaging and tracking techniques enabled the establishment of spatially and time-resolved hydrogen distributions during deformation. Based on realistic hydrogen partitioning among various nanoscopic trap sites, the contributions of particles to hydrogen trapping and the hydrogen effect at individual damaged particles were assessed quantitatively. Fracturing of coarse and irregular Al 7 Cu 2 Fe particles was found to be the predominant particle damage mode due to the spatial clustering and brittleness of these particles, but a hydrogen effect was not observed. The debonding of Mg 2 Si particles seemed to be the result of competition between hydrogen and clustering-induced stress localization, but detrimental effects of hydrogen on ductile fracture induced by accelerating interfacial debonding were found to be limited. The quantitative evaluation of particle damage in the present model material clarified a viable strategy for mitigating hydrogen embrittlement, which involves introducing and modifying intermetallic particles with strong hydrogen trapping capacities. [Display omitted] [ABSTRACT FROM AUTHOR]

The effect of hydrogen on the impact-abrasion wear behavior in bainitic steel has been investigated. It was found that the microcracking mechanism played a dominant role during impact-wear deformation under the action of hydrogen. The blocky retained austenite was mainly located at the prior austenite boundaries, or packet/block boundaries, which easily transformed into martensite by the action of hydrogen, and became the favorable sites for crack initiation. The microvoids or microcracks grew and coalesced along the high-angle grain boundaries, leading to many flakes generated on the worn surface, and decreased wear resistance. • The wear resistance decreased due to hydrogen, despite the increase of hardness. • Microcracking mechanism played a dominant role in wear under action of hydrogen. • Hydrogen induced transformation of blocky retained austenite to martensite. • Hydrogen accelerated microcracks growth up along high-angle grain boundaries. [ABSTRACT FROM AUTHOR]

• The high-temperature oxidation behavior of a Ni-Al-Y alloy shows a strong microstructure dependence. • A phase boundary wetting behavior concerning ion transport and Al-rich oxides was revealed. • High-temperature oxidation/annealing cause the precipitation of secondary γ -Ni strips inside Ni 5 Y-based grains. • A well-matched orientation relationship between γ -Ni (FCC) and Ni 5 Y (HCP) was stated. • The parallel precipitates inside Ni 5 Y-based grains provide extra interfaces for the further oxidation of Al and Y. The direct evidence for a precipitation-induced oxidation behavior (800 °C/200 h) of a Ni-Al-Y alloy was reported using multiscale microstructural characterizations. The precipitation of secondary γ -Ni strips within Ni 5 Y-based phase was governed by the solubility of Al in Ni 5 Y and the high-temperature holding. The well-matched orientation relationship (OR) between face-centered cubic (FCC) γ -Ni and hexagonal close-packed (HCP) Ni 5 Y induced the internal oxidation of reactive components (Al and Y) within Ni 5 Y-based phase, thusly resulting in the formation of parallel Y 4 Al 2 O 9 (YAM) strips and Al 2 O 3 along the phase boundaries (PBs) of YAM/Ni 5 Y in a wetting manner. The rest Ni within oxidized Ni 5 Y-based phase governed the external NiO scale. [ABSTRACT FROM AUTHOR]

Yttrium is an attractive component for nickel base alloys to improve high-temperature oxidation resistance. However, the application suffers from microstructure related problem, due to less unconscious of Y-related oxidation behavior, especially interacting with other key components, such as aluminium. This study introduces the discovery of microstructure depended external and internal oxidation behaviors based on four simplified Ni-Al-Y alloys during isothermally exposing at 800°C/1000°C in air. Using multiscale microstructural characterizations and thermodynamic calculations, different oxidation layer thicknesses have been observed in the four alloys, especially varying with Y and Al concentrations. In the three high-Y-content alloys, Y-related microstructures are found to strongly drive the oxidation process. Original-Ni 5 Y compound with strong tendency to precipitate secondary γ -Ni strip is favorable to the formation of inner oxidation layer containing mixed oxide particles, whereas original- γ -Ni phase drives the formation of outer scale of NiO. Dense and well-configured lamella-like phase boundaries (PBs) are beneficial to inhibiting the development of the inner layer, compared to coarse and irregular PBs. The resistance to inner oxidation of minor-Y-addition alloy has been significantly improved at 1000°C, benefiting from the mixed oxides along grain boundaries (GBs) and front of inner oxidation layers. From the thermodynamic basis, a type of modified diagram retrieved from ternary isothermal section is utilized to exhibit the oxide evolution, which is consistent with experimental results, especially for those complicated products. [Display omitted] [ABSTRACT FROM AUTHOR]

Citrus canker caused by Xanthomonas citri subsp. citri (Xcc) is one of the most devastating diseases in citrus industry worldwide. Most citrus cultivars such as sweet orange are susceptible to canker disease. Here, we utilized wild citrus to identify canker-resistant germplasms, and found that Atalantia buxifolia, a primitive (distant-wild) citrus, exhibited remarkable resistance to canker disease. Although the susceptibility gene LATERAL ORGAN BOUNDARIES 1 (LOB1) could also be induced in Atalantia after canker infection, the induction extent was far lower than that in sweet orange. In addition, three of amino acids encoded by transcription factor TFIIAγ in Atalantia (AbTFIIAγ) exhibited difference from those in sweet orange (CsTFIIAγ) which could stabilize the interaction between effector PthA4 and effector binding element (EBE) of LOB1 promoter. The mutation of AbTFIIAγ did not change its interaction with transcription factor binding motifs (TFBs). However, the AbTFIIAγ could hardly support the LOB1 expression induced by the PthA4. In addition, the activity of AbLOB1 promoter was significantly lower than that of CsLOB1 under the induction by PthA4. Our results demonstrate that natural variations of AbTFIIAγ and effector binding element (EBE) in the AbLOB1 promoter are crucial for the canker disease resistance of Atalantia. The natural mutations of AbTFIIAγ gene and AbLOB1 promoter in Atalantia provide candidate targets for improving the resistance to citrus canker disease. Author summary: It has been well documented that most citrus cultivars are susceptible to canker disease, while little is known about the resistance or susceptibility of primitive or wild citrus to canker disease. This study reveals that primitive citrus (Atalantia buxifolia) is highly resistant to citrus canker. Transcriptome data demonstrated that Atalantia had an active resistance response to the infection of Xcc, compared with susceptible sweet orange. Our results indicated that natural variations of AbTFIIAγ gene and AbLOB1 promoter contributed to the resistance. Hence, we propose that the natural mutations of AbTFIIAγ gene and AbLOB1 promoter could provide candidate targets for breeding canker resistant citrus. [ABSTRACT FROM AUTHOR]

This study developed a powder feeding laser metal deposition (LMD) method that can be used to achieve a layer-by-layer fabrication of component grade material for efficiently screening the properties of different chemical compositions and determining the optimized composition range for TRIP stainless steel. The 13Cr-xNi-(10-x)Mn-3Al steel with continuous graded composition was produced by the LMD method. An optimized composition range for TRIP stainless steel was determined by testing the properties including hardness, austenite content and surface potential of positions with different compositions. The suggested Ni content is between 3%–6% and Mn content is between 4%–7%. This study demonstrates the potential of LMD method to accelerate the development of steel economically. Unlabelled Image • The 13Cr-xNi-(10-x)Mn-3Al steel with continuous graded composition was produced by laser metal deposition method. • An optimized composition range for the steel was determined efficiently by screening microscopic properties on one specimen. This study provide a guide for exploring the relationship between chemical composition, microstructure, and mechanical properties. [ABSTRACT FROM AUTHOR]

Summary: Long intergenic non‐coding RNAs (lincRNAs) play important roles in various biological processes in plants. However, little information is known about the evolutionary characteristics of lincRNAs among closely related plant species. Here, we present a large‐scale comparative study of lincRNA transcription patterns in nine citrus species. By strand‐specific RNA‐sequencing, we identified 18 075 lincRNAs (14 575 lincRNA loci) from 34 tissue samples. The results indicated that the evolution of lincRNA transcription is more rapid than that of mRNAs. In total, 82.8–97.6% of sweet orange (Citrus sinensis) lincRNA genes were shown to have homologous sequences in other citrus genomes. However, only 15.5–28.8% of these genes had transcribed homologous lincRNAs in these citrus species, presenting a strong contrast to the high conservation of mRNA transcription (81.6–84.7%). Moreover, primitive and modern citrus lincRNAs were preferentially expressed in reproductive and vegetative organs, respectively. Evolutionarily conserved lincRNAs showed higher expression levels and lower tissue specificity than species‐specific lincRNAs. Notably, we observed a similar tissue expression pattern of homologous lincRNAs in sweet orange and pummelo (Citrus grandis), suggesting that these lincRNAs may be functionally conserved and selectively maintained. We also identified and validated a lincRNA with the highest expression in fruit that acts as an endogenous target mimic (eTM) of csi‐miR166c, and two lincRNAs that act as a precursor and target of csi‐miR166c, respectively. These lincRNAs together with csi‐miR166c could form an eTM166‐miR166c‐targeted lincRNA regulatory network that possibly affects citrus fruit development. Significance Statement: Here, 18 075 lincRNAs have been identified from 34 tissue samples from nine citrus species. The data uncover the rapid turnover of lincRNA transcription among different citrus species and highlights the potential contribution of the eTM166‐miR166‐targeted lincRNA regulatory network to fruit development. [ABSTRACT FROM AUTHOR]

Highlights • Large numbers of EPRVs segments were found in Citrinae genomes. • Simple repeats and transposable elements flanked the EPRVs segments. • There were several integration events during the speciation of Citrinae species. Abstract Endogenous pararetroviruses (EPRVs) are characterized in several plant genomes and their biological effects have been reported. In this study, hundreds of EPRV segments were identified in six Citrinae genomes. A total of 1034 EPRV segments were identified in the genomes of sweet orange, 2036 in pummelo, 598 in clementine mandarin, 752 in Ichang papeda, 2060 in citron and 245 in atalantia. Genomic analysis indicated that EPRV segments tend to cluster as hot spots in the genomes, particularly on chromosome 2 and 5. Large numbers of simple repeats and transposable elements were identified in the 2-kb flanking regions of the EPRV segments. Comparative genomic analysis and PCR experiments showed that there are highly conserved EPRV segments and species-specific EPRV segments between the Citrinae genomes. Phylogenetic analysis suggested that the integration events of EPRVs could initiate in a common progenitor of Citrinae species and repeatedly occur during the Citrinae divergence. [ABSTRACT FROM AUTHOR]

In plant, a few 22-nt mi RNAs direct cleavages of their targets and trigger the biogenesis of phased small interfering RNAs (phasi RNAs) in plant. In this study, we characterized a mi RNA triggering phasi RNAs generation, miR3954, and explored its downstream target genes and potential function. Our results demonstrated that miR3954 showed specific expression in the flowers of citrus species, and it targeted a NAC transcription factor ( Cs7 g22460) and two non-coding RNA transcripts (lnc RNAs, Cs1 g09600 and Cs1 g09635). The production of phasi RNAs was detected from transcripts targeted by miR3954, and was further verified in both sequencing data and transient expression experiments. Phasi RNAs derived from the two lnc RNAs targeted not only miR3954-targeted NAC gene but also additional NAC homologous genes. No homologous genes of these two lnc RNAs were found in plants other than citrus species, implying that this miR3954-lnc RNAs-phasi RNAs- NAC pathway is likely citrus-specific. Transgenic analysis indicated that the miR3954-overexpressing lines showed decreased transcripts of lnc RNA, elevated abundance of phasi RNAs and reduced expression of NAC genes. Interestingly, the overexpression of miR3954 leads to early flowering in citrus plants. In summary, our results illustrated a model of the regulatory network of miR3954-lnc RNA-phasi RNAs- NAC, which may be functionally involved in flowering in citrus. [ABSTRACT FROM AUTHOR]

[Display omitted] • A high-throughput experiment for steels based on LMD and GTHT was developed. A machine learning model possessing microstructure input terminals was put forward. • The average error of validation set in microhardness can be as low as 14.37 HV. • The reported strategy holds the promise for the application to other martensite steels. Accurately predicting properties of steels containing martensite by using models based on traditional strengthening mechanisms remains a challenge. In this study, a smart machine learning model possessing two-dimensional microstructure input terminals was developed using high-throughput experiments and machine learning on steels for low-temperature service. An algorithm based on a convolutional neural network enriched with the two-dimensional input terminals increased the prediction accuracy, achieving an average microhardness error of as low as 14.37 HV for the validation set. The improved prediction accuracy is ascribed to the comprehensive strengthening mechanism and coupling of strengthening effects contained in the multifarious input terminals. The information acquisition and cross-correlation of substructures related to strengthening mechanism played an important role. The reported strategy can deepen the cognition of the strengthening mechanism of tempered martensite. It is promising for application to different steels containing tempered martensite. [ABSTRACT FROM AUTHOR]

In this study, the effect of microstructure evolution on the impact properties of high-strength low-alloy (HSLA) steel plates was investigated. Two positions (surface and inner) throughout the thickness direction of a block of the selected steel were comprehensively investigated using mechanical tests and microstructural characterization techniques. Considering the combination of structural units, carbides, and dislocation density, the best performance of strength and toughness were found in the surface and inner samples, respectively. The exceptional ductile–brittle transition temperature (DBTT) behavior was attributed to the carbide spacing distribution caused by the adopted thermo-mechanically controlled processing (TMCP). [ABSTRACT FROM AUTHOR]