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1.
Artigo em Inglês | MEDLINE | ID: mdl-34988606

RESUMO

This study uses a general formulation of integrated visual grading regression (IVGR) and applies it to cone beam computed tomography (CBCT) scan data related to anatomical landmarks for dental implantology. The aim was to assess and predict a minimum acceptable dose for diagnostic imaging and reporting. A skull phantom was imaged with a CBCT unit at various diagnostic exposures. Key anatomical landmarks within the images were independently reviewed by three trained observers. Each provided an overall image quality score. Statistical analysis was carried out to examine the acceptability of the images taken, using an IVGR analysis that was formulized as a three-stage protocol including defining an integrated score, development of an ordinal regression, and investigation of the possibility for dose reduction through estimated parameters. For a unit increase in the logarithm of radiation dose, the odds ratio that the integrated score for an image assessed by observers being rated in a higher category was 3.940 (95% confidence interval: 1.016-15.280). When assessed by the observers, the minimum dose required to achieve a 75% probability for an image to be classified as at least acceptable was 1346.91 mGy·cm2 dose area product (DAP), a 31% reduction compared to the 1962 mGy·cm2 DAP default dosage of the CBCT unit. The kappa values of the intra and inter-observer reliability indicated moderate agreements, while a discrepancy among observers was also identified because each, as expected, perceived visibility differently. The results of this work demonstrate the IVGR's predictive value of dose saving in the effort to reduce dose to patients while maintaining reportable diagnostic image quality.

2.
Front Plant Sci ; 12: 775051, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34868173

RESUMO

Genes have been lost or weakened from cultivated rice during rice domestication and breeding. Weedy rice (Oryza sativa f. spontanea) is usually recognized as the progeny between cultivated rice and wild rice and is also known to harbor an gene pool for rice breeding. Therefore, identifying genes from weedy rice germplasms is an important way to break the bottleneck of rice breeding. To discover genes from weedy rice germplasms, we constructed a genetic map based on w-hole-genome sequencing of a F2 population derived from the cross between LM8 and a cultivated rice variety. We further identified 31 QTLs associated with 12 important agronomic traits and revealed that ORUFILM03g000095 gene may play an important role in grain length regulation and participate in grain formation. To clarify the genomic characteristics from weedy rice germplasms of LM8, we generated a high-quality genome assembly using single-molecule sequencing, Bionano optical mapping, and Hi-C technologies. The genome harbored a total size of 375.8 Mb, a scaffold N50 of 24.1 Mb, and originated approximately 0.32 million years ago (Mya) and was more closely related to Oryza sativa ssp. japonica. and contained 672 unique genes. It is related to the formation of grain shape, heading date and tillering. This study generated a high-quality reference genome of weedy rice and high-density genetic map that would benefit the analysis of genome evolution for related species and suggested an effective way to identify genes related to important agronomic traits for further rice breeding.

3.
Artigo em Inglês | MEDLINE | ID: mdl-34911666

RESUMO

BACKGROUND AND PURPOSE: The purpose of this review was to examine the reported factors that affect the reliability of Computed Tomography (CT) numbers and their impact on clinical applications in diagnostic scanning, dental imaging, and radiation therapy dose calculation. METHODS: A comprehensive search of the literature was conducted using Medline (PubMed), Google Scholar, and Ovid databases which were searched using the keywords CT number variability, CT number accuracy and uniformity, tube voltage, patient positioning, patient off-centring, and size dependence. A narrative summary was used to compile the findings under the overarching theme. DISCUSSION: A total of 47 articles were identified to address the aim of this review. There is clear evidence that CT numbers are highly dependent on the energy level applied based on the effective atomic number of the scanned tissue. Furthermore, body size and anatomical location have also indicated an influence on measured CT numbers, especially for high-density materials such as bone tissue and dental implants. Patient off-centring was reported during CT imaging, affecting dose and CT number reliability, which was demonstrated to be dependent on the shaping filter size. CONCLUSION: CT number accuracy for all energy levels, body sizes, anatomical locations, and degrees of patient off-centring is observed to be a variable under certain common conditions. This has significant implications for several clinical applications. It is crucial for those involved in CT imaging to understand the limitations of their CT system to ensure radiologists and operators avoid potential pitfalls associated with using CT numbers as absolute values for diagnostic scanning, dental imaging, and radiation therapy dose calculation.

4.
J Imaging ; 7(11)2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34821866

RESUMO

The purpose of this work is to evaluate the impacts of body off-center positioning on CT numbers and dose index CTDIv of two scanners from GE. HD750 and APEX scanners were used to acquire a PBU60 phantom of Kagaku and a 062M phantom of CIRS respectively. CT images were acquired at various off-center positions under automatic tube current modulation using various peak voltages. CTDIv were recorded for each of the acquisitions. An abdomen section of the PBU60 phantom was used for CT number analysis and tissue inserts of the 062M phantom were filled with water balloons to mimic the human abdomen. CT numbers of central regions of interests were averaged using the Fiji software. As phantoms were lifted above the iso-center, both CTDIv and CT numbers were increased for the HD750 scanner whilst they were approximately constant for the APEX scanner. The measured sizes of anterior-posterior projection images were also increased for both scanners whilst the sizes of lateral projection images were increased for the HD750 scanner but decreased for the APEX scanner. Off-center correction algorithms were implemented in the APEX scanner. Matching the X-ray projection center with the system's iso-center could improve the accuracy of CT imaging.

5.
Front Psychol ; 12: 693557, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34777088

RESUMO

The previous research has mostly proposed that ethical leadership contributed to less deviant behavior; however, recent studies found that this relationship might not always be significant. Therefore, a deeper and more nuanced investigation of how and when ethical leadership influences deviant behavior is highly warranted. In the present research, drawing on social learning theory as our overarching theoretical framework, we posited that high level of LMX differentiation will impede the effect of ethical leadership on employee deviant behavior, and thus, ethical leadership could reduce employees' deviant behavior in teams with lower LMX differentiation rather than high LMX differentiation. Furthermore, we proposed that the interactive effect of ethical leadership and LMX differentiation on employee deviant behavior is mediated by employee psychological empowerment. More specifically, ethical leadership is more likely to enhance employee psychological empowerment in teams with low LMX differentiation than in teams with high LMX differentiation, and enhanced psychological empowerment contributed to less deviant behavior. Through a multi-source field study via 379 paired samples from the southwest of China, we found support for all of our hypotheses. The results' contribution to research on organizational behavior, limitations in the study, and future directions for researchers are also discussed.

6.
Ann Palliat Med ; 10(10): 10591-10599, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34763506

RESUMO

BACKGROUND: During the epidemic, the mental health of college students was generally poor, especially anxiety and depression, which should be treated using counseling and intervention. This study aimed to observe the influence of dialectical behavior therapy on the anxiety and depression of medical students during the normalization of the prevention and control of the COVID-19 epidemic. METHODS: A total of 26 medical students (experimental group) were treated with dialectical behavior therapy intervention for 4 weeks. Changes in depression, anxiety, and stress levels were assessed by the Patient Health Questionnaire (PHQ-9), the Generalized Anxiety Disorder (GAD-7) scale, the Somatic Self-rating Scale (SSS), and the Perceived Stress Scale (PSS-10). This group was compared with 26 medical students (control group) without intervention. RESULTS: The value-added scores of the PHQ-9 (t=2.543, P=0.014) and GAD-7 scales (t=3.790, P=0.000) in the experimental group were significantly higher than those in the control group, while in the SSS scale, the value-added score of the depressive symptoms subscale (t=2.234, P=0.030) in the experimental group was significantly higher than that of the control group. For the total score of the PSS-10 scale (t=2.435, P=0.018), the value-added score of the experimental group was significantly higher than that of the control group. CONCLUSIONS: The intervention of dialectical behavior therapy can effectively alleviate the depression and anxiety of medical students during the normalization of epidemic prevention and control. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2100048784.


Assuntos
COVID-19 , Terapia do Comportamento Dialético , Epidemias , Psicoterapia de Grupo , Estudantes de Medicina , Ansiedade/prevenção & controle , Transtornos de Ansiedade/prevenção & controle , Humanos , SARS-CoV-2
7.
Artigo em Inglês | MEDLINE | ID: mdl-34807678

RESUMO

Drawing upon Stress-as-Offense-to-Self theory, we develop a moderated mediation model whereby subordinate poor performance and leader well-being is linked by abusive supervision and this mediated relationship is further moderated by leaders' motives for abuse. Specifically, we posit that higher performance promotion motives will attenuate, whereas higher injury motives will exacerbate the relationship between abusive supervision and leader emotional exhaustion, due to their differential implications for leaders' ability to see themselves in a positive light. In a pilot study, we first examined and found support for the theorized mediation chain in a multiwave field study of organizational leaders (N = 71). In Study 1, we conducted a multiwave and multisource field study of leader-follower dyads (N = 274), which supported our predictions that the indirect effect between subordinate poor performance and leader emotional exhaustion via abusive supervision was strengthened for leaders higher on injury motives. In Study 2, we undertook a 2-week daily diary study with leaders (N = 129) to hone in on the latter half of our model, focusing on within-person dynamics linking abusive supervision and leader well-being and the moderating role of leader motives for abuse. Although the within-person relationship between abusive supervision and emotional exhaustion was positive within a given day across leaders, the lagged within-person relationship between abusive supervision and emotional exhaustion unfolded differently for leaders higher versus lower on injury motives. Namely, abusive supervision had a lingering detrimental effect on leader emotional exhaustion among leaders higher on injury motives. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

9.
Plant Biotechnol J ; 2021 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-34655511

RESUMO

Starch accounts for over 80% of the total dry weight in cereal endosperm and determines the kernel texture and nutritional quality. Amyloplasts, terminally differentiated plastids, are responsible for starch biosynthesis and storage. We screened a series of rice mutants with floury endosperm to clarify the mechanism underlying amyloplast development and starch synthesis. We identified the floury endosperm19 (flo19) mutant which shows opaque of the interior endosperm. Abnormal compound starch grains (SGs) were present in the endosperm cells of the mutant. Molecular cloning revealed that the FLO19 allele encodes a plastid-localized pyruvate dehydrogenase complex E1 component subunit α1 (ptPDC-E1-α1) that is expressed in all rice tissues. In vivo enzyme assays demonstrated that the flo19 mutant showed decreased activity of the plastidic pyruvate dehydrogenase complex. In addition, the amounts of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) were much lower in the developing flo19 mutant endosperm, suggesting that FLO19 participates in fatty acid supply for galactolipid biosynthesis in amyloplasts. FLO19 overexpression significantly increased seed size and weight, but did not affect other important agronomic traits, such as panicle length, tiller number and seed setting rate. An analysis of single nucleotide polymorphism data from a panel of rice accessions identified that the pFLO19L haplotype was positively associated with grain length, implying a potential application in rice breeding. In summary, our study demonstrates that FLO19 is involved in galactolipid biosynthesis which is essential for amyloplast development and starch biosynthesis in rice.

10.
Nanomaterials (Basel) ; 11(10)2021 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-34685191

RESUMO

The coupling strength between two-dimensional (2D) materials and substrate plays a vital role on thermal transport properties of 2D materials. Here we systematically investigate the influence of vacuum thermal annealing on the temperature-dependence of in-plane Raman phonon modes in monolayer graphene supported on silicon dioxide substrate via Raman spectroscopy. Intriguingly, raising the thermal annealing temperature can significantly enlarge the temperature coefficient of supported monolayer graphene. The derived temperature coefficient of G band remains mostly unchanged with thermal annealing temperature below 473 K, while it increases from -0.030 cm-1/K to -0.0602 cm-1/K with thermal annealing temperature ranging from 473 K to 773 K, suggesting the great impact of thermal annealing on thermal transport in supported monolayer graphene. Such an impact might reveal the vital role of coupling strength on phonon scattering and on the thermal transport property of supported monolayer graphene. To further interpret the thermal annealing mechanism, the compressive stress in supported monolayer graphene, which is closely related to coupling strength and is studied through the temperature-dependent Raman spectra. It is found that the variation tendency for compressive stress induced by thermal annealing is the same as that for temperature coefficient, implying the intense connection between compressive stress and thermal transport. Actually, 773 K thermal annealing can result in 2.02 GPa compressive stress on supported monolayer graphene due to the lattice mismatch of graphene and substrate. This study proposes thermal annealing as a feasible path to modulate the thermal transport in supported graphene and to design future graphene-based devices.

11.
J Phys Chem Lett ; 12(44): 10753-10760, 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34714072

RESUMO

Group-VA two-dimensional layered materials in a puckered honeycomb structure exhibit strong in-plane anisotropy and have emerged as new platforms for novel devices. Here, we report on systematic Raman investigations on exfoliated b-As flakes on the Ag1 and Ag2 polarization dependence on their symmetry, excitation wavelength, and flake thickness. The intensity maximums of both phonons are corrected in the b-As armchair direction under 633 nm excitation regardless of the flake thickness upon considering optical birefringence effects and interference effects. The intensity ratio of Ag1 to Ag2 modes under 532 nm excitation is useful for b-As crystalline orientation identification. Temperature-dependent Raman investigations reveal the linearly anharmonic behaviors of both phonons in the range from 173 to 293 K and a slightly greater first-order temperature coefficient in the zigzag direction. Our findings give deep insight into the in-plane phonon anisotropy and anharmonicity of b-As and provide a step toward future device applications.

12.
Front Bioeng Biotechnol ; 9: 723490, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34368109

RESUMO

Immunotherapy has emerged as a promising strategy for cancer treatment, in which durable immune responses were generated in patients with malignant tumors. In the past decade, biomaterials have played vital roles as smart drug delivery systems for cancer immunotherapy to achieve both enhanced therapeutic benefits and reduced side effects. Hydrogels as one of the most biocompatible and versatile biomaterials have been widely applied in localized drug delivery systems due to their unique properties, such as loadable, implantable, injectable, degradable and stimulus responsible. Herein, we have briefly summarized the recent advances on hydrogel-by-design delivery systems including the design of hydrogels and their applications for delivering of immunomodulatory molecules (e.g., cytokine, adjuvant, checkpoint inhibitor, antigen), immune cells and environmental regulatory substances in cancer immunotherapy. We have also discussed the challenges and future perspectives of hydrogels in the development of cancer immunotherapy for precision medicine at the end.

13.
Theor Appl Genet ; 134(10): 3443-3457, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34390352

RESUMO

KEY MESSAGE: A dwarfism gene LacDWARF1 was mapped by combined BSA-Seq and comparative genomics analyses to a 65.4 kb physical genomic region on chromosome 05. Dwarf architecture is one of the most important traits utilized in Cucurbitaceae breeding because it saves labor and increases the harvest index. To our knowledge, there has been no prior research about dwarfism in the sponge gourd. This study reports the first dwarf mutant WJ209 with a decrease in cell size and internodes. A genetic analysis revealed that the mutant phenotype was controlled by a single recessive gene, which is designated Lacdwarf1 (Lacd1). Combined with bulked segregate analysis and next-generation sequencing, we quickly mapped a 65.4 kb region on chromosome 5 using F2 segregation population with InDel and SNP polymorphism markers. Gene annotation revealed that Lac05g019500 encodes a gibberellin 3ß-hydroxylase (GA3ox) that functions as the most likely candidate gene for Lacd1. DNA sequence analysis showed that there is an approximately 4 kb insertion in the first intron of Lac05g019500 in WJ209. Lac05g019500 is transcribed incorrectly in the dwarf mutant owing to the presence of the insertion. Moreover, the bioactive GAs decreased significantly in WJ209, and the dwarf phenotype could be restored by exogenous GA3 treatment, indicating that WJ209 is a GA-deficient mutant. All these results support the conclusion that Lac05g019500 is the Lacd1 gene. In addition, RNA-Seq revealed that many genes, including those related to plant hormones, cellular process, cell wall, membrane and response to stress, were significantly altered in WJ209 compared with the wild type. This study will aid in the use of molecular marker-assisted breeding in the dwarf sponge gourd.


Assuntos
Cromossomos de Plantas/genética , Regulação da Expressão Gênica de Plantas , Giberelinas/metabolismo , Luffa/crescimento & desenvolvimento , Mutação , Fenótipo , Proteínas de Plantas/metabolismo , Íntrons , Luffa/genética , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Melhoramento Vegetal , Proteínas de Plantas/genética
14.
Front Psychol ; 12: 588793, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34393870

RESUMO

This paper's purpose is to test the employability paradox by adopting a combined linear and non-linear approach based on the conservation of resource (COR) theory and the prospect theory and further to discuss it in two groups of employees with different seniority following the career timetable perspective. A total of 623 pairs of matched employee and manager surveys was collected from 27 Chinese enterprises in two waves. Hierarchical regression analysis was used to test the hypotheses. The results show no paradox that perceived employability promotes both an employee's turnover intention and performance. Specifically, perceived employability has a significant inverted U-shaped effect on turnover intention but no direct influence on job performance. Seniority is a moderator, showing the curvilinear relationship only exhibits for employees with shorter work seniority (≤3 years), and a positive linear relationship between perceived employability and job performance only exists for employees with longer seniority (>3 years). This study emphasizes the value of employability for employers and proposes who is more suitable and what timetable should be followed for employability enhancement in practice. In addition, the study provides an enlightening finding of the inverted U-shaped relationship between perceived employability and turnover intention, applies the COR theory and the prospect theory to explain the non-linear relationship, validates the effect of too much of a good thing (TMGT), and negates the paradox from the perspective of the perceived general employability and career timetable.

15.
J Med Radiat Sci ; 2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34402591

RESUMO

INTRODUCTION: Patient positioning is an essential consideration for the optimisation of radiation dose during CT examinations. The study objectives seek to explore the effects of vertical off-centring, localiser direction (0° and 180°), and phantom positioning (supine and prone) on radiation dose, using three different tube voltages in multidetector computed tomography (MDCT) imaging. METHODS: The trunk of a PBU-60 anthropomorphic phantom was imaged using a Discovery CT750 HD - 128 slice (GE Healthcare). Images employing 0° and 180° localisers were acquired in supine and prone orientation for each combination of vertical off-centring (±100, ±60 and ±30 mm) and different tube voltages (80, 120 and 140 kVp), using the system's automatic tube current modulation (ATCM) function. The displayed volume CT dose index (CTDIvol ) and dose length product (DLP) were recorded. RESULTS: With incremental table off-centring of ±100 mm, the dose at 120 kVp in the supine position ranged from 63% to 196% (0° localiser) and from 66% to 191% (180° localiser) as compared to iso-centre. While in the prone position, the dose ranged from 62% to 195% (0° localiser); and 62% to 193% (180° localiser), with a notable dose increase at higher tube voltages. Dose variation and vertical off-centring showed a significant relationship for both 0° and 180° localisers (r = 0.94 and 0.96, respectively, P < 0.001). The CTDIvol variation between supine and prone phantom positions at ±100 mm off-centring was 0.22 mGy (2.9%), and 0.19 mGy (2.3%) when the 0° and 180 ° localisers were utilised, respectively. CONCLUSIONS: Phantom off-centring and localiser direction evidenced large dose variation. It is recommended that the 0° localiser is employed during CT examinations, in order to minimise the potential additional radiation dose which may result from off-centring and the use of lower tube voltages where clinically appropriate.

16.
J Appl Psychol ; 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34096748

RESUMO

Delegation is a critical tool for busy managers. Early delegation research suggests that managers are reluctant to delegate beyond a few highly competent employees or those with whom they have a strong relationship. Extending this line of research, we integrate signaling theory with a view of social networks as "prisms," to demonstrate the relevance of employees' network ties in the work unit for delegation. Signaling theory argues that when direct data about employee competence are mixed or ambiguous, decision makers will look for more indirect signals with which to make inferences about quality and reputation. One such signal is suggested by the networks as "prisms" perspective, which argues that network ties can operate as reputational signals in the absence of more direct quality data. Combining these insights and data from a field study and two follow-up laboratory studies, we find that in situations of moderate employee competence, managers will draw positive reputational inferences and be more willing to delegate to employees when such employees are more central in the friendship network of the work unit as well as when they share common memberships in friendship cliques with the managers. These network ties, however, do not matter for delegation decisions when there are direct data to indicate that employees are highly competent or clearly poor performers. Our lab studies elucidate the mediating role of perceived reputation. Implications for theory and practice are discussed. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

17.
Int J Nanomedicine ; 16: 2897-2915, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33907399

RESUMO

Background: Surgery is considered to be a potentially curative approach for gastric cancer. However, most cases are diagnosed at a very advanced stage for the lack of typical symptoms in the initial stage, which makes it difficult to completely surgical resect of tumors. Early diagnosis and precise personalized intervention are urgent issues to be solved for improving the prognosis of gastric cancer. Herein, we developed an RGD-modified ROS-responsive multifunctional nanosystem for near-infrared (NIR) imaging and photothermal therapy (PTT) against gastric cancer. Methods: Firstly, the amphiphilic polymer was synthesized by bromination reaction and nucleophilic substitution reaction of carboxymethyl chitosan (CMCh) and 4-hydroxymethyl-pinacol phenylborate (BAPE). Then, it was used to encapsulate indocyanine green (ICG) and modified with RGD to form a smart multifunctional nanoparticle targeted to gastric cancer (CMCh-BAPE-RGD@ICG). The characteristics were determined, and the targeting capacity and biosafety were evaluated both in vitro and in vivo. Furthermore, CMCh-BAPE-RGD@ICG mediated photothermal therapy (PTT) effect was studied using gastric cancer cells (SGC7901) and SGC7901 tumor model. Results: The nanoparticle exhibited suitable size (≈ 120 nm), improved aqueous stability, ROS-responsive drug release, excellent photothermal conversion efficiency, enhanced cellular uptake, and targeting capacity to tumors. Remarkably, in vivo studies suggested that CMCh-BAPE-RGD@ICG could accurately illustrate the location and margin of the SGC7901 tumor through NIR imaging in comparison with non-targeted nanoparticles. Moreover, the antitumor activity of CMCh-BAPE-RGD@ICG-mediated PTT could effectively suppress tumor growth by inducing necrosis and apoptosis in cancer cells. Additionally, CMCh-BAPE-RGD@ICG demonstrated excellent biosafety both in vitro and in vivo. Conclusion: Overall, our study provides a biocompatible theranostic nanoparticle with enhanced tumor-targeting ability and accumulation to realize NIR image-guided PTT in gastric cancer.


Assuntos
Nanopartículas Multifuncionais/química , Nanopartículas Multifuncionais/uso terapêutico , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/terapia , Animais , Ácidos Borônicos/química , Linhagem Celular Tumoral , Quitosana/análogos & derivados , Quitosana/química , Feminino , Humanos , Verde de Indocianina/química , Verde de Indocianina/farmacocinética , Camundongos Endogâmicos BALB C , Oligopeptídeos/química , Fototerapia/métodos , Terapia Fototérmica , Polímeros/química , Espécies Reativas de Oxigênio/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Theor Appl Genet ; 134(5): 1531-1543, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33688983

RESUMO

KEY MESSAGE: we identified a functional chromogen gene C from wild rice, providing a new insight of anthocyanin biosynthesis pathway in indica and japonica. Accumulation of anthocyanin is a desirable trait to be selected in rice domestication, but the molecular mechanism of anthocyanin biosynthesis in rice remains largely unknown. In this study, a novel allele of chromogen gene C, OrC1, from Oryza rufipongon was cloned and identified as a determinant regulator of anthocyanin biosynthesis. Although OrC1 functions in purple apiculus, leaf sheath and stigma in indica background, it only promotes purple apiculus in japonica. Transcriptome analysis revealed that OrC1 regulates flavonoid biosynthesis pathway and activates a few bHLH and WD40 genes of ternary MYB-bHLH-WD40 complex in indica. Differentially expressed genes and metabolites were found in the indica and japonica backgrounds, indicating that OrC1 activated the anthocyanin biosynthetic genes OsCHI, OsF3H and OsANS and produced six metabolites independently. Artificial selection and domestication of C1 gene in rice occurred on the coding region in the two subspecies independently. Our results reveal the regulatory system and domestication of C1, provide new insights into MYB transcript factor involved in anthocyanin biosynthesis, and show the potential of engineering anthocyanin biosynthesis in rice.


Assuntos
Antocianinas/biossíntese , Regulação da Expressão Gênica de Plantas , Metaboloma , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Compostos Cromogênicos/metabolismo , Perfilação da Expressão Gênica , Oryza/classificação , Oryza/genética , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas Proto-Oncogênicas c-myb/genética , Proteínas Proto-Oncogênicas c-myb/metabolismo
19.
Sci Rep ; 11(1): 3660, 2021 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-33574456

RESUMO

Two subspecies of rice, Oryza sativa ssp. indica and O. sativa ssp. japonica, with reproductive isolation and differences in morphology and phenotypic differences, were established during the process of rice domestication. To understand how domestication has changed the transcriptomes of the two rice subspecies and given rise to the phenotypic differences, we obtained approximately 700 Gb RNA-Seq data from 26 indica and 25 japonica accessions, and identified 97,005 transcribed fragments and 4579 novel transcriptionally active regions. The two rice subspecies had significantly different gene expression profiles, we identified 1,357 (3.3% in all genes) differentially expressed genes (DEGs) between indica and japonica rice. Combining existing gene function studies, it is found that some of these differential genes are related to the differentiation of the two subspecies, such as grain shape and cold tolerance, etc. Functional annotation of these DEGs indicates that they are involved in cell wall biosynthesis and reproductive processes. Furthermore, compared with the non-DEGs, the DEGs from both subspecies had more 5'flanking regions with low polymorphism to divergence ratios, indicating a stronger positive selection pressure on the regulation of the DEGs. This study improves our understanding of the rice genome by comparatively analyzing the transcriptomes of indica and japonica rice and identifies DEGs those may be responsible for the reproductive isolation and phenotypic differences between the two rice subspecies.


Assuntos
Domesticação , Evolução Molecular , Oryza/genética , Transcriptoma/genética , Produtos Agrícolas/genética , Fluxo Gênico/genética , Variação Genética/genética , Humanos , Oryza/crescimento & desenvolvimento , Fenótipo , Polimorfismo Genético/genética
20.
Plant Biotechnol J ; 19(2): 300-310, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32757315

RESUMO

Heading date is a key agronomic trait affecting crop yield. In rice, Early heading date 1 (Ehd1) is an important B-type response regulator in determination of heading date. Although many regulatory factors of Ehd1 expression have been functionally characterized, the direct regulators of Ehd1 largely remain to be identified. Here, we identified a new regulator of Ehd1, OsRE1, that directly binds to the A-box motif in the Ehd1 promoter. Osre1 confers an early heading phenotype due to elevated expression levels of Ehd1. OsRE1 is a nucleus-localized bZIP transcription factor with a diurnal rhythmic expression pattern. Furthermore, we identified an OsRE1-interacting protein, OsRIP1, and demonstrated that OsRIP1 can repress the transcript expression of Ehd1 in an OsRE1-dependent manner. Our genetic data showed that OsRE1 and OsRIP1 may function upstream of Ehd1 in regulating heading date. Together, our results suggest that OsRE1 functions cooperatively with OsRIP1 to regulate heading date through finely modulating the expression of Ehd1. In addition, OsRE1 and OsRIP1 are two minor heading date regulators, which are more desirable for fine-tuning heading date to improve rice regional adaptability.


Assuntos
Oryza , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Oryza/genética , Oryza/metabolismo , Fenótipo , Fotoperíodo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
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