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Traditional optical information recognition (OIR), particle capture and manipulation require many optical devices or mechanical moving system components to achieve a specific function, which is difficult to achieve integration. This paper proposes a new method to realize these functions by using multi-focus metalens combining spectrum and polarization selection. The design incorporates three spectral bands, namely 500â nm, 580â nm, and 660â nm, within the visible light range. Additionally, it utilizes either left-handed or right-handed circularly polarized (LCP/RCP) light, resulting in six distinct focus focusing effects on a single focal plane. By analyzing the normalized light intensity (NLI) at the corresponding focus position, the OIR of any wavelength and polarization detection in the design can be realized, and the particle capture at different focusing positions can be realized. Our work can provide a new idea for the high integration of on-chip light recognition and operation and inspire the design of a highly integrated optical system with a smaller size and more substantial function.
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In this paper, a 1 × 2 photonic switch is designed based on a silicon-on-insulator (SOI) platform combined with the phase change material (PCM), Sb2S3, assisted by the direct binary search (DBS) algorithm. The designed photonic switch exhibits an impressive operating bandwidth ranging from 1450 to 1650 nm. The device has an insertion loss (IL) from 0.44 dB to 0.70 dB (of less than 0.7 dB) and cross talk (CT) from -26 dB to -20 dB (of less than -20 dB) over an operating bandwidth of 200 nm, especially an IL of 0.52 dB and CT of -24 dB at 1550 nm. Notably, the device is highly compact, with footprints of merely 3 × 4 µm2. Furthermore, we have extended the device's functionality for multifunctional operation in the C-band that can serve as both a 1 × 2 photonic switch and a 3 dB photonic power splitter. In the photonic switch mode, the device demonstrates an IL of 0.7 dB and a CT of -13.5 dB. In addition, when operating as a 3 dB photonic power splitter, the IL is less than 0.5 dB.
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KEY MESSAGE: The fiber length-related qFL-A12-5 identified in CSSLs introgressed from Gossypium barbadense into Gossypium hirsutum was fine-mapped to an 18.8 kb region on chromosome A12, leading to the identification of the GhTPR gene as a potential regulator of cotton fiber length. Fiber length is a key determinant of fiber quality in cotton, and it is a key target of artificial selection for breeding and domestication. Although many fiber length-related quantitative trait loci have been identified, there are few reports on their fine mapping or candidate gene validation, thus hampering efforts to understand the mechanistic basis of cotton fiber development. Our previous study identified the qFL-A12-5 associated with superior fiber quality on chromosome A12 in the chromosome segment substitution line (CSSL) MBI7747 (BC4F3:5). A single segment substitution line (CSSL-106) screened from BC6F2 was backcrossed to construct a larger segregation population with its recurrent parent CCRI45, thus enabling the fine mapping of 2852 BC7F2 individuals using denser simple sequence repeat markers to narrow the qFL-A12-5 to an 18.8 kb region of the genome, in which six annotated genes were identified in Gossypium hirsutum. Quantitative real-time PCR and comparative analyses led to the identification of GH_A12G2192 (GhTPR) encoding a tetratricopeptide repeat-like superfamily protein as a promising candidate gene for qFL-A12-5. A comparative analysis of the protein-coding regions of GhTPR among Hai1, MBI7747, and CCRI45 revealed two non-synonymous mutations. The overexpression of GhTPR resulted in longer roots in Arabidopsis, suggesting that GhTPR may regulate cotton fiber development. These results provide a foundation for future efforts to improve cotton fiber length.
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Gossypium , Locos de Características Quantitativas , Humanos , Gossypium/genética , Mapeamento Cromossômico/métodos , Fenótipo , Melhoramento Vegetal , Fibra de Algodão , Estudos de Associação GenéticaRESUMO
KEY MESSAGE: In this study, we present AAQSP as an extension of existing NGS-BSA applications for identifying stable QTLs at high resolution. GhPAP16 and GhIQD14 fine mapped on chromosome D09 of upland cotton are identified as important candidate genes for lint percentage (LP). Bulked segregant analysis combined with next generation sequencing (NGS-BSA) allows rapid identification of genome sequence differences responsible for phenotypic variation. The NGS-BSA approach applied to crops mainly depends on comparing two bulked DNA samples of individuals from an F2 population. Since some F2 individuals still maintain high heterozygosity, heterosis will exert complications in pursuing NGS-BSA in such populations. In addition, the genetic background influences the stability of gene expression in crops, so some QTLs mapped in one segregating population may not be widely applied in crop improvement. The AAQSP (Association Analysis of QTL-seq on Semi-homologous Populations) reported in our study combines the optimized scheme of constructing BSA bulks with NGS-BSA analysis in two (or more) different parental genetic backgrounds for isolating the stable QTLs. With application of AAQSP strategy and construction of a high-density linkage map, we have successfully identified a QTL significantly related to lint percentage (LP) in cultivated upland cotton, followed by map-based cloning to dissect two candidate genes, GhPAP16 and GhIQD14. This study demonstrated that AAQSP can efficiently identify stable QTLs for complex traits of interest, and thus accelerate the genetic improvement of upland cotton and other crop plants.
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Sequenciamento de Nucleotídeos em Larga Escala , Locos de Características Quantitativas , Mapeamento Cromossômico , Produtos Agrícolas/genética , Patrimônio Genético , Gossypium/genética , Vigor Híbrido , FenótipoRESUMO
KEY MESSAGE: Based on the integration of QTL-mapping and regulatory network analyses, five high-confidence stable QTL regions, six candidate genes and two microRNAs that potentially affect the cottonseed oil content were discovered. Cottonseed oil is increasingly becoming a promising target for edible oil with its high content of unsaturated fatty acids. In this study, a recombinant inbred line (RIL) cotton population was constructed to detect quantitative trait loci (QTLs) for the cottonseed oil content. A total of 39 QTLs were detected across eight different environments, of which five QTLs were stable. Forty-three candidate genes potentially involved in carbon metabolism, fatty acid synthesis and triacylglycerol biosynthesis processes were further obtained in the stable QTL regions. Transcriptome analysis showed that nineteen of these candidate genes expressed during the developing cottonseed ovules and may affect the cottonseed oil content. Besides, transcription factor (TF) and microRNA (miRNA) co-regulatory network analyses based on the nineteen candidate genes suggested that six genes, two core miRNAs (ghr-miR2949b and ghr-miR2949c), and one TF GhHSL1 were considered to be closely associated with the cottonseed oil content. Moreover, four vital genes were validated by quantitative real-time PCR (qRT-PCR). These results provide insights into the oil accumulation mechanism in developing cottonseed ovules through the construction of a detailed oil accumulation model.
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Óleo de Sementes de Algodão , Gossypium , Mapeamento Cromossômico , Óleo de Sementes de Algodão/metabolismo , Gossypium/genética , Gossypium/metabolismo , Locos de Características QuantitativasRESUMO
Linolenic acid (LA) is gaining more interest within the scientific community. This is because it has a potential medical role in reducing the risk of inflammation, carcinogenesis, atherosclerosis and diabetes and is a valuable nutraceutical for human health. The oleaginous fungus Mucor circinelloides produces a high lipid content (36%), including valuable polyunsaturated fatty acids (PUFAs). However, the critical step in which oleic acid (OA) is converted into LA is not efficient at supplying enough substrates for PUFA synthesis. Hence, we propose a method to increase LA production based on genetic engineering. The overexpression of the Δ12-desaturase gene from M. circinelloides and Mortierella alpina increased the LA content and improved the lipid accumulation (from 14.9% to 21.6% in the Δ12-desaturase gene of the M. circinelloides overexpressing strain (Mc-D12MC) and from 14.9% to 18.7% in the Δ12-desaturase gene of M. alpina overexpressing strain (Mc-D12MA)). Additionally, the up-regulated expression levels of these genes targeted the genes involved in NADPH production, implying that the elevated Δ12-desaturase gene may function as a critical regulator of NADPH and lipid synthesis in M. circinelloides. This study provides the first evidence to support the design of metabolic engineering related to LA and PUFA production in M. circinelloides for potential industrial applications.
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Ácidos Graxos Dessaturases , Mucor , Ácido alfa-Linolênico , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Dessaturases/metabolismo , Mucor/genética , NADP/metabolismo , Ácido alfa-Linolênico/biossínteseRESUMO
BACKGROUND: Mucor circinelloides WJ11 is a high-lipid producing strain and an excellent producer of γ-linolenic acid (GLA) which is crucial for human health. We have previously identified genes that encode for AMP-activated protein kinase (AMPK) complex in M. circinelloides which is an important regulator for lipid accumulation. Comparative transcriptional analysis between the high and low lipid-producing strains of M. circinelloides showed a direct correlation in the transcriptional level of AMPK genes with lipid metabolism. Thus, the role of Snf-ß, which encodes for ß subunit of AMPK complex, in lipid accumulation of the WJ11 strain was evaluated in the present study. RESULTS: The results showed that lipid content of cell dry weight in Snf-ß knockout strain was increased by 32 % (from 19 to 25 %). However, in Snf-ß overexpressing strain, lipid content of cell dry weight was decreased about 25 % (from 19 to 14.2 %) compared to the control strain. Total fatty acid analysis revealed that the expression of the Snf-ß gene did not significantly affect the fatty acid composition of the strains. However, GLA content in biomass was increased from 2.5 % in control strain to 3.3 % in Snf-ß knockout strain due to increased lipid accumulation and decreased to 1.83 % in Snf-ß overexpressing strain. AMPK is known to inactivate acetyl-CoA carboxylase (ACC) which catalyzes the rate-limiting step in lipid synthesis. Snf-ß manipulation also altered the expression level of the ACC1 gene which may indicate that Snf-ß control lipid metabolism by regulating ACC1 gene. CONCLUSIONS: Our results suggested that Snf-ß gene plays an important role in regulating lipid accumulation in M. circinelloides WJ11. Moreover, it will be interesting to evaluate the potential of other key subunits of AMPK related to lipid metabolism. Better insight can show us the way to manipulate these subunits effectively for upscaling the lipid production. Up to our knowledge, it is the first study to investigate the role of Snf-ß in lipid accumulation in M. circinelloides.
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Proteínas Quinases Ativadas por AMP/metabolismo , Lipídeos/biossíntese , Mucor/metabolismo , Metabolismo dos LipídeosRESUMO
BACKGROUND: AMP-activated protein kinase (AMPK) is an important regulator for lipid accumulation, potentially known to have an inhibitory role in lipid synthesis. It inactivates acetyl-CoA carboxylase (ACC), an important regulatory enzyme required for lipid synthesis. However, in Mucor circinelloides, AMPK and its association with lipid accumulation has not been studied yet. OBJECTIVES: To identify AMPK genes in M. circinelloides and to compare their expression levels in high and low lipid-producing strains of M. circinelloides to predict the possible roles of AMPK in lipid metabolism and to select candidate genes for further studies to enhance lipid accumulation. RESULTS: Two genes for α-subunit, one for ß-subunit and six for γ-subunit were identified and annotated. Bioinformatic analysis confirmed the presence of typical conserved domains in these genes. Furthermore, transcriptional profiling displayed marked differences in expression kinetics of subunits among the selected strains. The expression of AMPK genes decreased rapidly in WJ11, high lipid producer strain during the lipid accumulation phase while contrasting profile of expression was observed in CBS 277.49, low lipid producer strain. CONCLUSION: The present study has shown the association of AMPK genes with lipid metabolism at the transcriptional level. The involvement of Snf-α1, Snf-α2, Snf-ß, Snf-γ1, Snf-γ4, Snf-γ5 subunits were shown to be more pronounced and could potentially be further explored in future studies.
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Proteínas Quinases Ativadas por AMP , Proteínas Fúngicas , Mucor , Proteínas Quinases Ativadas por AMP/classificação , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Biologia Computacional , Ácidos Graxos/genética , Ácidos Graxos/metabolismo , Proteínas Fúngicas/classificação , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Anotação de Sequência Molecular , Mucor/enzimologia , Mucor/genética , Mucor/metabolismo , Transcriptoma/genéticaRESUMO
KEY MESSAGE: Background-independent (BI) and stably expressed (SE) quantitative trait loci (QTLs) were identified using two sets of introgression lines across multiple environments. Genetic background more greatly affected fiber quality traits than environmental factors. Sixty-one SE-QTLs, including two BI-QTLs, were novel and 48 SE-QTLs, including seven BI-QTLs, were previously reported. Cotton fiber quality traits are controlled by QTLs and are susceptible to environmental influence. Fiber quality improvement is an essential goal in cotton breeding but is hindered by limited knowledge of the genetic basis of fiber quality traits. In this study, two sets of introgression lines of Gossypium hirsutum × G. barbadense were used to dissect the QTL stability of three fiber quality traits (fiber length, strength and micronaire) across environments using 551 simple sequence repeat markers selected from our high-density genetic map. A total of 76 and 120 QTLs were detected in the CCRI36 and CCRI45 backgrounds, respectively. Nine BI-QTLs were found, and 78 (41.71%) of the detected QTLs were reported previously. Thirty-nine and 79 QTLs were SE-QTLs in at least two environments in the CCRI36 and CCRI45 backgrounds, respectively. Forty-eight SE-QTLs, including seven BI-QTLs, were confirmed in previous reports, and 61 SE-QTLs, including two BI-QTLs, were considered novel. These results indicate that genetic background more strongly impacts on fiber quality traits than environmental factors. Twenty-three clusters with BI- and/or SE-QTLs were identified, 19 of which harbored favorable alleles from G. barbadense for two or three fiber quality traits. This study is the first report using two sets of introgression lines to identify fiber quality QTLs across environments in cotton, providing insights into the effect of genetic backgrounds and environments on the QTL expression of fiber quality and important information for the genetic basis underlying fiber quality traits toward QTL cloning and molecular breeding.
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Mapeamento Cromossômico , Fibra de Algodão , Ligação Genética , Gossypium/genética , Locos de Características Quantitativas , Alelos , Cruzamentos Genéticos , Genoma de Planta , Repetições de Microssatélites , Fenótipo , Melhoramento VegetalRESUMO
BACKGROUND: Verticillium wilt (VW), also known as "cotton cancer," is one of the most destructive diseases in global cotton production that seriously impacts fiber yield and quality. Despite numerous attempts, little significant progress has been made in improving the VW resistance of upland cotton. The development of chromosome segment substitution lines (CSSLs) from Gossypium hirsutum × G. barbadense has emerged as a means of simultaneously developing new cotton varieties with high-yield, superior fiber, and resistance to VW. RESULTS: In this study, VW-resistant investigations were first conducted in an artificial greenhouse, a natural field, and diseased nursery conditions, resulting in the identification of one stably VW-resistant CSSL, MBI8255, and one VW-susceptible G. hirsutum, CCRI36, which were subsequently subjected to biochemical tests and transcriptome sequencing during V991 infection (0, 1, and 2 days after inoculation). Eighteen root samples with three replications were collected to perform multiple comparisons of enzyme activity and biochemical substance contents. The findings indicated that VW resistance was positively correlated with peroxidase and polyphenol oxidase activity, but negatively correlated with malondialdehyde content. Additionally, RNA sequencing was used for the same root samples, resulting in a total of 77,412 genes, of which 23,180 differentially expressed genes were identified from multiple comparisons between samples. After Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis on the expression profiles identified using Short Time-series Expression Miner, we found that the metabolic process in the biological process, as well as the pathways of phenylpropanoid biosynthesis and plant hormone signal transduction, participated significantly in the response to VW. Gene functional annotation and expression quantity analysis indicated the important roles of the phenylpropanoid metabolic pathway and oxidation-reduction process in response to VW, which also provided plenty of candidate genes related to plant resistance. CONCLUSIONS: This study concentrates on the preliminary response to V991 infection by comparing the VW-resistant CSSL and its VW-susceptible recurrent parent. Not only do our findings facilitate the culturing of new resistant varieties with high yield and superior performance, but they also broaden our understanding of the mechanisms of cotton resistance to VW.
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Cromossomos de Plantas/genética , Gossypium/genética , Gossypium/microbiologia , Transcriptoma/genética , Verticillium/patogenicidade , Regulação da Expressão Gênica de Plantas/genéticaRESUMO
Fiber quality and yield are important traits of cotton. Quantitative trait locus (QTL) mapping is a prerequisite for marker-assisted selection (MAS) in cotton breeding. To identify QTLs for fiber quality and yield traits, 4 backcross-generation populations (BC1F1, BC1S1, BC2F1, and BC3F0) were developed from an interspecific cross between CCRI36 (Gossypium hirsutum L.) and Hai1 (G. barbadense L.). A total of 153 QTLs for fiber quality and yield traits were identified based on data from the BC1F1, BC1S1, BC2F1 and BC3F0 populations in the field and from the BC2F1 population in an artificial disease nursery using a high-density genetic linkage map with 2292 marker loci covering 5115.16 centimorgans (cM) from the BC1F1 population. These QTLs were located on 24 chromosomes, and each could explain 4.98-19.80% of the observed phenotypic variations. Among the 153 QTLs, 30 were consistent with those identified previously. Specifically, 23 QTLs were stably detected in 2 or 3 environments or generations, 6 of which were consistent with those identified previously and the other 17 of which were stable and novel. Ten QTL clusters for different traits were found and 9 of them were novel, which explained the significant correlations among some phenotypic traits in the populations. The results including these stable or consensus QTLs provide valuable information for marker-assisted selection (MAS) in cotton breeding and will help better understand the genetic basis of fiber quality and yield traits, which can then be used in QTL cloning.
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Fibra de Algodão , Gossypium/genética , Locos de Características Quantitativas , Cruzamentos Genéticos , Gossypium/embriologia , Sementes/genéticaRESUMO
Chromosome segment substitution lines (CSSLs) are ideal materials for identifying genetic effects. In this study, CSSL MBI7561 with excellent fiber quality that was selected from BC4F3:5 of CCRI45 (Gossypium hirsutum) × Hai1 (Gossypium barbadense) was used to construct 3 secondary segregating populations with 2 generations (BC5F2 and BC5F2:3). Eighty-one polymorphic markers related to 33 chromosome introgressive segments on 18 chromosomes were finally screened using 2292 SSR markers which covered the whole tetraploid cotton genome. A total of 129 quantitative trait loci (QTL) associated with fiber quality (103) and yield-related traits (26) were detected on 17 chromosomes, explaining 0.85-30.35% of the phenotypic variation; 39 were stable (30.2%), 53 were common (41.1%), 76 were new (58.9%), and 86 had favorable effects on the related traits. More QTL were distributed in the Dt subgenome than in the At subgenome. Twenty-five stable QTL clusters (with stable or common QTL) were detected on 22 chromosome introgressed segments. Finally, the 6 important chromosome introgressed segments (Seg-A02-1, Seg-A06-1, Seg-A07-2, Seg-A07-3, Seg-D07-3, and Seg-D06-2) were identified as candidate chromosome regions for fiber quality, which should be given more attention in future QTL fine mapping, gene cloning, and marker-assisted selection (MAS) breeding.
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Cromossomos de Plantas/genética , Gossypium/genética , Locos de Características Quantitativas/genética , Mapeamento Cromossômico/métodos , Fibra de Algodão , Cruzamentos Genéticos , Genoma de Planta/genética , FenótipoRESUMO
Magnetorheological elastomer (MRE) is a type of magnetic soft material consisting of ferromagnetic particles embedded in a polymeric matrix. MRE-based devices have characteristics of adjustable stiffness and damping properties, and highly nonlinear and hysteretic force-displacement responses that are dependent on external excitations and applied magnetic fields. To effectively implement the devices in mitigating the hazard vibrations of structures, numerically traceable and computationally efficient models should be firstly developed to accurately present the unique behaviors of MREs, including the typical Payne effect and strain stiffening of rubbers etc. In this study, the up-to-date phenomenological models for describing hysteresis response of MRE devices are experimentally investigated. A prototype of MRE isolator is dynamically tested using a shaking table in the laboratory, and the tests are conducted based on displacement control using harmonic inputs with various loading frequencies, amplitudes and applied current levels. Then, the test results are used to identify the parameters of different phenomenological models for model performance evaluation. The procedure of model identification can be considered as solving a global minimization optimization problem, in which the fitness function is the root mean square error between the experimental data and the model prediction. The genetic algorithm (GA) is employed to solve the optimization problem for optimal model parameters due to its advantages of easy coding and fast convergence. Finally, several evaluation indices are adopted to compare the performances of different models, and the result shows that the improved LuGre friction model outperforms other models and has optimal accuracy in predicting the hysteresis response of the MRE device.
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Elastômeros/química , Modelos Teóricos , Reologia/instrumentação , Campos Magnéticos , Imãs/química , Reologia/métodos , VibraçãoRESUMO
BACKGROUND: How to develop new cotton varieties possessing high yield traits of Upland cotton and superior fiber quality traits of Sea Island cotton remains a key task for cotton breeders and researchers. While multiple attempts bring in little significant progresses, the development of Chromosome Segment Substitution Lines (CSSLs) from Gossypium barbadense in G. hirsutum background provided ideal materials for aforementioned breeding purposes in upland cotton improvement. Based on the excellent fiber performance and relatively clear chromosome substitution segments information identified by Simple Sequence Repeat (SSR) markers, two CSSLs, MBI9915 and MBI9749, together with the recurrent parent CCRI36 were chosen to conduct transcriptome sequencing during the development stages of fiber elongation and Secondary Cell Wall (SCW) synthesis (from 10DPA and 28DPA), aiming at revealing the mechanism of fiber development and the potential contribution of chromosome substitution segments from Sea Island cotton to fiber development of Upland cotton. RESULTS: In total, 15 RNA-seq libraries were constructed and sequenced separately, generating 705.433 million clean reads with mean GC content of 45.13% and average Q30 of 90.26%. Through multiple comparisons between libraries, 1801 differentially expressed genes (DEGs) were identified, of which the 902 up-regulated DEGs were mainly involved in cell wall organization and response to oxidative stress and auxin, while the 898 down-regulated ones participated in translation, regulation of transcription, DNA-templated and cytoplasmic translation based on GO annotation and KEGG enrichment analysis. Subsequently, STEM software was performed to explicate the temporal expression pattern of DEGs. Two peroxidases and four flavonoid pathway-related genes were identified in the "oxidation-reduction process", which could play a role in fiber development and quality formation. Finally, the reliability of RNA-seq data was validated by quantitative real-time PCR of randomly selected 20 genes. CONCLUSIONS: The present report focuses on the similarities and differences of transcriptome profiles between the two CSSLs and the recurrent parent CCRI36 and provides novel insights into the molecular mechanism of fiber development, and into further exploration of the feasible contribution of G. barbadense substitution segments to fiber quality formation, which will lay solid foundation for simultaneously improving fiber yield and quality of upland cotton through CSSLs.
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Cromossomos de Plantas/genética , Fibra de Algodão , Perfilação da Expressão Gênica , Gossypium/crescimento & desenvolvimento , Gossypium/genética , Hibridização Genética , Parede Celular/metabolismo , Gossypium/citologia , Fenótipo , Reprodutibilidade dos TestesRESUMO
BACKGROUND: Verticillium wilt (VW) caused by Verticillium dahliae (Kleb) is one of the most destructive diseases of cotton. The identification of highly resistant QTLs or genes in the whole cotton genome is quite important for developing a VW-resistant variety and for further molecular design breeding. RESULTS: In the present study, BC1F1, BC1S1, and BC2F1 populations derived from an interspecific backcross between the highly resistant line Hai1 (Gossypium barbadense L.) and the susceptible variety CCRI36 (G. hirsutum L.) as the recurrent parent were constructed. Quantitative trait loci (QTL) related to VW resistance were detected in the whole cotton genome using a high-density simple sequence repeat (SSR) genetic linkage map from the BC1F1 population, with 2292 loci covering 5115.16 centiMorgan (cM) of the cotton (AD) genome, and the data concerning VW resistance that were obtained from four dates of BC2F1 in the artificial disease nursery and one date of BC1S1 and BC2F1 in the field. A total of 48 QTLs for VW resistance were identified, and 37 of these QTLs had positive additive effects, which indicated that the G. barbadense alleles increased resistance to VW and decreased the disease index (DI) by about 2.2-10.7. These QTLs were located on 19 chromosomes, in which 33 in the A subgenome and 15 QTLs in the D subgenome. The 6 QTLs were found to be stable. The 6 QTLs were consistent with those identified previously, and another 42 were new, unreported QTLs, of which 31 QTLs were from G. barbadense. By meta-analysis, 17 QTL hotspot regions were identified and 10 of them were new, unreported hotspot regions. 29 QTLs in this paper were in 12 hotspot regions and were all from G. barbadense. CONCLUSIONS: These stable or consensus QTL regions warrant further investigation to better understand the genetics and molecular mechanisms underlying VW resistance. This study provides useful information for further comparative analysis and marker-assisted selection in the breeding of disease-resistant cotton. It may also lay an important foundation for gene cloning and further molecular design breeding for the entire cotton genome.
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Cruzamentos Genéticos , Resistência à Doença/genética , Gossypium/genética , Gossypium/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Locos de Características Quantitativas , Verticillium , Mapeamento Cromossômico , Ligação Genética , Genética Populacional , FenótipoRESUMO
This study aimed to improve the lipid and biomass yields of Mucor circinelloides WJ11 by implementing four different fed-batch fermentation strategies, varied in time and glucose concentration (S1-S4). The S1 fermentation strategy yielded the highest biomass, lipid, and fatty acid content (22 ± 0.7 g/L, 53 ± 1.2 %, and 28 ± 1.6 %) after 120 and 144 h, respectively. The γ-linolenic acid titer of 0.75 ± 0.0 g/L was greatest in S3 after 48 h. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used to analyze the transcription of key genes involved in lipid accumulation. The glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and ATP-citrate lyase genes showed increased expression levels. Fourier-transform infrared (FTIR) spectroscopy was used to analyze the biochemical profile during fermentation strategies. Optimal abiotic factors for production efficiency included pH 6.5, 25-26 °C, 15 % (v/v) inoculum, 500 rpm, 20 %-30 % dissolved oxygen, and 120 h fermentation. Glucose co-feeding offers valuable insights to develop effective fermentation strategies for lipid production.
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Ácidos Graxos , Mucor , Fermentação , Biomassa , Mucor/metabolismo , Ácidos Graxos/metabolismo , Glucose/metabolismoRESUMO
Mucor circinelloides has been exploited as model filamentous fungi for studies of genetic manipulation of lipogenesis. It is widely recognized that lipid accumulation is increased when there is a lack of nitrogen source in oleaginous microorganism. Nitrogen metabolism in filamentous fungi is a complex process that can be regulated by the global nitrogen regulator AreA. In this study, we cultivated the areA-knockout and -overexpression strains obtained in our previous study, using 20 different nitrogen sources. It emerged that the disruption of AreA in M. circinelloides reduced its sensitivity to nitrogen availability, resulting in increased lipid synthesis. Specially, the areA-knockout strain was unable to fully utilize many nitrogen sources but the ammonium and glutamate. We continued to investigate lipid production at different molar C/N ratios using glucose as sole carbon source and ammonium sulfate as sole nitrogen source, of which the high C/N ratios activate high lipid accumulation. By comparing the experimental results with transcriptional analysis, we were able to identify the optimal process conditions suitable for lipid accumulation and potential targets for future metabolic engineering.
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Carbono , Proteínas Fúngicas , Mucor , Nitrogênio , Mucor/metabolismo , Mucor/genética , Nitrogênio/metabolismo , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Carbono/metabolismo , Regulação Fúngica da Expressão Gênica , Metabolismo dos Lipídeos/genética , Lipídeos/biossínteseRESUMO
Lipid biosynthesis is a significant metabolic response to nitrogen starvation in oleaginous fungi. The oleaginous fungus Mucor circinelloides copes with nitrogen stress by degrading AMP through AMP deaminase (AMPD). However, the mechanism of AMPD in regulating lipogenesis remains largely unclear. To elucidate the mechanism of AMPD in lipid synthesis in this M. circinelloides, we identified two genes (ampd1 and ampd2) encoding AMPD and constructed an ampd double knockout mutant. The engineered M. circinelloides strain elevated cell growth and lipid accumulation, as well as the content of oleic acid (OA) and gamma-linolenic acid (GLA). In addition to the expected increase in transcription levels of genes associated with lipid and TAG synthesis, we observed suppression of lipid degradation and reduced amino acid biosynthesis. This suggested that the deletion of AMPD genes induces the redirection of carbon towards lipid synthesis pathways. Moreover, the pathways related to nitrogen metabolism, including nitrogen assimilation and purine metabolism (especially energy level), were also affected in order to maintain homeostasis. Further analysis discovered that the transcription factors (TFs) related to lipid accumulation were also regulated. This study provides new insights into lipid biosynthesis in M. circinelloides, indicating that the trigger for lipid accumulation is not entirely AMPD-dependent and suggest that there may be additional mechanisms involved in the initiation of lipogenesis.
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AMP Desaminase , Metabolismo dos Lipídeos , Mucor , Metabolismo dos Lipídeos/genética , AMP Desaminase/genética , AMP Desaminase/metabolismo , Nitrogênio/metabolismo , LipídeosRESUMO
In the oleaginous fungus Mucor circinelloides, lipid accumulation is regulated by nitrogen metabolism, which is regulated by the areA gene, a member of the GATA zinc finger transporter family and a major regulator for nitrogen metabolism. However, the role of areA in lipid accumulation in this fungus has not been reported. In order to explore the regulatory effect of areA gene on nitrogen metabolism and lipid accumulation in M. circinelloides, we constructed areA gene knockout and overexpression strains. Then, the recombinant strains were cultured and their biochemical indexes were measured. Simultaneously, transcriptomic studies on the recombinant strains were conducted to infer the regulatory mechanism of areA. The results showed that the areA knockout strain accumulated more lipid, which is 42 % higher than the control. While the areA overexpressing strain obtained the higher biomass accumulation (23 g/L) and used up the nitrogen source in the medium earlier than the control strain and knockout strain. Transcriptome data analysis showed that nr and nit-6 genes related to nitrogen metabolism were up-regulated. And the expression levels of key genes acc and aclY were higher in the areA knockout strain than others, which was positively correlated with the increased lipid accumulation. In addition, in knockout strains, protein catabolism tended to provide substrates for the lipid production, and the expression levels of the related genes were also higher than others. These results indicated that the areA gene not only controls the transcription level of genes related to nitrogen metabolism but also affects lipid accumulation.
Assuntos
Metabolismo dos Lipídeos , Mucor , Metabolismo dos Lipídeos/genética , Mucor/genética , Mucor/metabolismo , Lipídeos , Nitrogênio/metabolismoRESUMO
Background: Alzheimer's disease (AD) is the predominant cause of dementia on a global scale, significantly impacting the health of the elderly population. The pathogenesis of AD is closely linked to neuroinflammation. The present study employs a bibliometric analysis to examine research pertaining to neuroinflammation and AD within the last decade, with the objective of providing a comprehensive overview of the current research profile, hotspots and trends. Methods: This research conducted a comprehensive review of publications within the Science Citation Index Expanded of the Web of Science Core Collection Database spanning the years 2014 to 2024. Bibliometric analyses were performed using VOSviewer (version 1.6.19) and CiteSpace (version 6.3.R1) software to visualize data on countries, institutions, authors, journals, keywords, and references. Results: A total of 3,833 publications on neuroinflammation and AD were included from January 2014 to January 2024. Publications were mainly from the United States and China. Zetterberg, Henrik emerged as the author with the highest publication output, while Edison, Paul was identified as the most cited author. The most productive journal was Journal of Alzheimers Disease, and the most co-cited was Journal of Neuroinflammation. Research hotspot focused on microglia, mouse models, oxidative stress, and amyloid-beta through keyword analysis. Additionally, keywords such as blood-brain barrier and tau protein exhibited prolonged citation bursts from 2022 to 2024. Conclusion: This study provides a comprehensive review of the last 10 years of research on neuroinflammation and AD, including the number and impact of research findings, research hotspots, and future trends. The quantity of publications in this field is increasing, mainly in the United States and China, and there is a need to further strengthen close cooperation with different countries and institutions worldwide. Presently, research hotspots are primarily concentrated on microglia, with a focus on inhibiting their pro-inflammatory responses and promoting their anti-inflammatory functions as a potential direction for future investigations.