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1.
Environ Microbiol Rep ; 16(2): e13256, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38575150

RESUMO

This study examined the effects of three Bacillus strains and one Saccharomyces cerevisiae strain on nitrogen transformation and microbial communities in pig and chicken manure compost. The findings revealed that the use of compound microbial inoculants increased the compost temperature, accelerated moisture reduction, enhanced cellulase activity, and stimulated the accumulation of NH4 +-N, NO3 --N, and total nitrogen (TN), resulting in a 9% increase in TN content. The abundance of Firmicutes decreased by 3.95% at the maturation phase, while Actinobacteria and Bacteroidetes increased by 1.64% and 1.85%, respectively. Inoculation led to an increase in amoA, nxrA and nifH gene copy numbers, while simultaneously reducing the abundance of nirK, nosZ and nirS genes. It also resulted in an increase in functional enzyme levels, specifically nif and amo, with a corresponding decrease in nor. Clostridium, Phascolarctobacterium, Eubacterium and Faecalibacterium from the class Clostridium, which have a significant correlation with nifH and nxrA genes, suggest their likely crucial role in nitrogen retention and fixation. Inoculation aided in the removal of pathogenic bacteria and antibiotic resistance genes (ARGs) like fluoroquinolones, nucleosides and nitroimidazole. This study provides effective theoretical support for the mechanism of nitrogen retention and fixation, and for improving the quality of compost.


Assuntos
Compostagem , Microbiota , Animais , Suínos , Esterco , Gado , Nitrogênio , Solo , Bactérias/genética , Microbiota/genética
2.
BMC Public Health ; 24(1): 1035, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38614987

RESUMO

INTRODUCTION: Widespread concern exists in today's world regarding self-harm and interpersonal violence. This study to analyze the changes in temporal trends and spatial patterns of risk factors and burdens of self-harm and interpersonal violence using the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. METHODS: Temporal trends in self-harm and interpersonal violence were initially summarized using the estimated annual percentage change (EAPC). Data were compiled and visualized to delineate changes in disease burden and factors influencing self-harm and interpersonal violence from 1990 to 2019, stratified by gender, age and GBD region. RESULTS: In 2019, the DALY rates of self-harm were 424.7(95% UI 383.25, 466.93). Over the period from 1999 to 2019, self-harm exhibited an overall decreasing trend, with the EAPC of -1.5351 (95% CI -1.6194, -1.4507), -2.0205 (95% CI -2.166, -1.8740) and -2.0605 (95% CI -2.2089, -1.9119), respectively. In contrast, the incidence rate of interpersonal violence was significantly higher than self-harm, with a rate of 413.44 (95% UI 329.88, 502.37) per 100,000 population. Mortality and DALYs of interpersonal violence were lower than those of self-harm, at 5.22 (95% UI 4.87, 5.63) and 342.43 (95% UI 316.61, 371.55). Disease burden of self-harm and interpersonal violence varied by gender, age groups and region. Specific risk factors showed that alcohol use, high temperature and drug use were the main risk factors for self-harm, while alcohol use, intimate partner violence and high temperature were associated with interpersonal violence. Low temperature was a common protective factor for both self-harm and interpersonal violence. The burden of self-harm and interpersonal violence was attributed to different factors influences in different SDI regions. CONCLUSIONS: The study explored temporal trends and spatial distribution of the global disease burden of self-harm and interpersonal violence, emphasizing the significant impact of factors such as alcohol use, temperature, and drug use on disease burden. Further research and policy actions are needed to interpret recent changes of disease burden of self-harm and interpersonal violence, and dedicated efforts should be implemented to devise evidence-based interventions and policies to curtail risk factors and protect high-risk groups.


Assuntos
Violência por Parceiro Íntimo , Comportamento Autodestrutivo , Humanos , Carga Global da Doença , Comportamento Autodestrutivo/epidemiologia , Consumo de Bebidas Alcoólicas , Fatores de Risco
3.
Int J Biol Macromol ; 264(Pt 2): 130673, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38458290

RESUMO

Noble metal nanoparticles show good application prospects in biosensors and anti-tumor drug research. Herein, the near-spherical silver­palladium bimetallic nanoparticles supported by elm pod polysaccharide (EPP-AgPd1.5 NPs) were prepared by using the elm pod polysaccharide (EPP). EPP acts as a stabilizer and reducing agent due to its water solubility and weak reducing ability. The particle size of EPP-AgPd1.5 NPs was 33.6 ± 5.5 nm. In addition, EPP-AgPd1.5 NPs had peroxidase-like activity to catalyze 3,3',5,5'-tetramethylbenzidine (TMB) to oxidized TMB by catalyzing H2O2 to OH. Based on the peroxidase-like activity of EPP-AgPd1.5 NPs, a method for detecting glutathione was established, and the detection limit and linear range of glutathione concentration were 0.279 µM and 0-400 µM, respectively. More importantly, the photothermal conversion efficiency of EPP-AgPd1.5 NPs reached 39.7 %, and their inhibition rate in HeLa cells reached 69.9 %. Silver­palladium bimetallic nanoparticles stabilized by EPP had good performance in glutathione detection and anti-tumor drugs.


Assuntos
Nanopartículas Metálicas , Peroxidase , Humanos , Prata , Paládio , Peróxido de Hidrogênio , Células HeLa , Polissacarídeos/farmacologia , Glutationa , Colorimetria/métodos
4.
BMC Geriatr ; 24(1): 131, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38373895

RESUMO

BACKGROUND: As stroke has become the leading cause of death and disability in China, it has induced a heavy disease burden on society, families, and patients. Despite much attention within the literature, the effect of multiple risk factors on length of stay (LOS) and inpatient costs in China is still not fully understood. AIM: To analyse the association between the number of risk factors combined and inpatient costs among adults with stroke and explore the mediating effect of LOS on inpatient costs. METHODS: A retrospective cross-sectional study was conducted among stroke patients in a tertiary hospital in Nantong City from January 2018 to December 2019. Lifestyle factors (smoking status, exercise), personal disease history (overweight, hypertension, dyslipidemia, diabetes mellitus, atrial fibrillation), family history of stroke, and demographic characteristics were interviewed by trained nurses. Inpatient costs and LOS were extracted from electronic medical records. Hierarchical multiple linear regression models and mediation analysis were used to examine the direct and indirect effects of the number of risk factors combined for stroke on inpatient costs. RESULTS: A total of 620 individuals were included, comprising 391 ischaemic stroke patients and 229 haemorrhagic stroke patients, and the mean age was 63.2 years, with 60.32% being male. The overall mean cost for stroke inpatients was 30730.78 CNY ($ 4444.91), and the average length of stay (LOS) was 12.50 days. Mediation analysis indicated that the greater number of risk factors was not only directly related to higher inpatient costs (direct effect = 0.16, 95%CI:[0.11,0.22]), but also indirectly associated with inpatient cost through longer LOS (indirect effect = 0.08, 95% CI: [0.04,0.11]). Furthermore, patients with high risk of stroke had longer LOS than those in low-risk patients, which in turn led to heavier hospitalization expenses. CONCLUSIONS: Both the greater number of risk factors and high-risk rating among stroke patients increased the length of stay and inpatient costs. Preventing and controlling risk behaviors of stroke should be strengthened.


Assuntos
Isquemia Encefálica , Acidente Vascular Cerebral , Humanos , Masculino , Feminino , Tempo de Internação , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/terapia , Pacientes Internados , Estudos Retrospectivos , Estudos Transversais , Hospitalização , Fatores de Risco , China/epidemiologia , Custos Hospitalares
5.
Talanta ; 270: 125557, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38128284

RESUMO

As the development of global population and industry civilization, the accurate and sensitive detection of intended analytes is becoming an important and great challenge in the field of environmental, medical, and public safety. Recently, electrochemical biosensors have been constructed and used in sensing fields, such as antibiotics, pesticides, specific markers of cancer, and so on. Functional materials have been designed and prepared to enhance detection performance. Among all reported materials, covalent organic frameworks (COFs) are emerging as porous crystalline materials to construct electrochemical biosensors, because COFs have many unique advantages, including large surface area, high stability, atom-level designability, and diversity, to achieve a far better sensing performance. In this comprehensive review, we not only summarize state-of-the-art electrochemical biosensors based on COFs and their hybrid materials but also highlight and discuss some typical examples in detail. We finally provide the challenge and future perspective of COFs-based electrochemical biosensors.

6.
Int J Biol Macromol ; 253(Pt 1): 126552, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37660849

RESUMO

Organophosphorus pesticides can inhibit the activity of acetylcholinesterase and cause neurological diseases. Therefore, it is crucial to establish an efficient and sensitive platform for organophosphorus pesticide detection. In this work, we extracted aloe polysaccharide (AP) from aloe vera with the number average molecular weight of 27760 Da and investigated its reducing property. We prepared aloe polysaccharide stabilized platinum nanoflowers (AP-Ptn NFs), their particle size ranges were 29.4-67.3 nm. Furthermore, AP-Ptn NFs exhibited excellent oxidase-like activity and the catalytic kinetics followed the typical Michaelis-Menten equation. They showed strong affinity for 3,3',5,5'-tetramethylbenzidine substrates. More importantly, we developed a simple and effective strategy for the sensitive colorimetric detection of organophosphorus pesticides in food using biocompatible AP-Ptn NFs. The detection range was 0.5 µg/L - 140 mg/L, which was wider than many previously reported nanozyme detection systems. This colorimetric biosensor had good selectivity and good promise for bioassay analysis.


Assuntos
Aloe , Técnicas Biossensoriais , Praguicidas , Praguicidas/análise , Compostos Organofosforados/análise , Acetilcolinesterase/química , Platina , Aloe/química , Colorimetria , Polissacarídeos/química
7.
Dalton Trans ; 52(33): 11552-11557, 2023 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-37545403

RESUMO

Functional materials are considered one of the most critical factors in constructing high-performance electrochemical aptasensors in the sensing field. In this work, the microporous Zr-MOF UiO-66 (UiO = Universitetet i Oslo) is selected for assembly with carbon nanotubes (CNTs) to prepare a CNT@UiO-66 composite. The as-synthesized CNT@UiO-66 composite has a high surface area, excellent stability, good electrical conductivity, and abundant Zr(IV) sites, conferring it great potential for application in fabricating high-performance electrochemical aptasensors. It is gratifying that this electrochemical impedimetric aptasensor can detect trace oxytetracycline (OTC) from 0.01 to 0.7 pg mL-1 with a low limit of detection (LOD) of 1.48 fg mL-1. Meanwhile, this fabricated sensor based on CNT@UiO-66 has fine stability, excellent selectivity, and available reproducibility. In particular, the CNT@UiO-66-based aptasensor can quantitatively detect the OTC concentration in real samples.

8.
Polymers (Basel) ; 15(14)2023 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-37514537

RESUMO

Hydroquinone poses a major threat to human health and is refractory to degradation, so it is important to establish a convenient detection method. In this paper, we present a novel colorimetric method for the detection of hydroquinone based on a peroxidase-like Pd nanozyme. The vancomycin-stabilized palladium nanoparticles (Van-Pdn NPs, n = 0.5, 1, 2) were prepared using vancomycin as a biological template. The successful synthesis of Van-Pdn NPs (n = 0.5, 1, 2) was demonstrated by UV-vis spectrophotometry, transmission electron microscopy, and X-ray diffraction. The sizes of Pd nanoparticles inside Van-Pd0.5 NPs, Van-Pd1 NPs, and Van-Pd2 NPs were 2.6 ± 0.5 nm, 2.9 ± 0.6 nm, and 4.3 ± 0.5 nm, respectively. Furthermore, Van-Pd2 NPs exhibited excellent biocompatibility based on the MTT assay. More importantly, Van-Pd2 NPs had good peroxidase-like activity. A reliable hydroquinone detection method was established based on the peroxidase-like activity of Van-Pd2 NPs, and the detection limit was as low as 0.323 µM. Therefore, vancomycin improved the peroxidase-like activity and biocompatibility of Van-Pd2 NPs. Van-Pd2 NPs have good application prospects in the colorimetric detection of hydroquinone.

9.
BMC Psychiatry ; 23(1): 497, 2023 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-37434160

RESUMO

BACKGROUND: Long working hours and effort-reward imbalance (ERI) among medical workers may contribute to poor mental health and reduced productivity. However, the potential mechanisms among them are not well understood. This study aimed to explore the role of depressive symptoms and ERI in the relationship between long working hours and presenteeism among village doctors. METHODS: We conducted a cross-sectional study in Jiangsu Province, eastern China. 705 village doctors were assessed for working hours, ERI (the Effort-Reward Imbalance Questionnaire, ERI questionnaire), presenteeism (6-item Stanford Presenteeism Scale, SPS-6 Scale), and depressive symptoms (12-item General Health Questionnaire, GHQ-12). A moderated mediation model was used to test the role of depressive symptoms (M), and ERI (W) in the relationship between long working hours (X) and presenteeism (Y). RESULTS: 45.11% of the village doctors worked more than 55 h per week, and 55.89% were exposed to ERI. The prevalence of depressive symptoms among Chinese village doctors was 40.85%. Long working hours (≥ 55 h per week) were significantly associated with presenteeism behaviors (ß = 2.17, P < 0.001). Mediation analysis demonstrated that depressive symptoms (GHQ score > 3) could partly mediate the relationship between long working hours and presenteeism (indirect effect ß = 0.64, P < 0.001). Moderated mediation further indicated that the interaction of long working hours and ERI was significantly and positively associated with depressive symptoms, which in turn predicted elevated presenteeism behaviors. CONCLUSIONS: Depressive symptoms had a mediating role in the association of long working hours with presenteeism behaviors among Chinese village doctors and ERI augment their negative effects.


Assuntos
Depressão , Médicos , Presenteísmo , Recompensa , Humanos , Estudos Transversais , Depressão/epidemiologia , População do Leste Asiático , Médicos/psicologia
10.
Wei Sheng Yan Jiu ; 52(2): 226-231, 2023 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-37062684

RESUMO

OBJECTIVE: To analyze the epidemiological characteristics of foodborne disease outbreaks in China and to provide references for formulating prevention strategies of foodborne diseases in China. METHODS: Collect the monitoring data reported in China's foodborne disease outbreak monitoring system from 2011 to 2020, and calculate relevant indicators. RESULTS: During 2011 and 2020 in 30 provinces(autonomous region, municipality), a total of 35 806 foodborne disease outbreaks were reported, which caused 266 968 illnesses. The western region had the largest number of reported incidents and the largest number of patients, Yunnan Province had the largest percentage of outbreaks(17.7%) and the largest percentage of cases(15.81%). Poisonous mushrooms and microorganisms are the main pathogenic factors. Poisonous mushrooms caused the largest percentage of foodborne disease outbreaks, accounting for 29.09% of the total. Microorganisms caused the largest percentage of cases, accounting for 35.69% of the total. Salmonella and Vibrio parahaemolyticus are the main pathogens. Catering service units were the main places of foodborne disease outbreaks, responsible for the largest percentage of outbreaks(49.31%) and cases(70.59%). CONCLUSION: From 2011 to 2020, the number of reported incidents and the number of patients in foodborne disease outbreaks in China showed an upward trend.


Assuntos
Doenças Transmitidas por Alimentos , Humanos , China/epidemiologia , Doenças Transmitidas por Alimentos/epidemiologia , Surtos de Doenças
11.
Int J Biol Macromol ; 233: 123513, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36739057

RESUMO

The development of nanozymes using noble metal nanoparticles to replace natural peroxidase in bio-related detection has been gain great interest. Noble metal nanoparticles with small size have large specific surface area. However, small noble metal nanoparticles tend to aggregate without stabilizer. In this paper, small Pd nanoparticles (3-6 nm) stabilized by bitter gourd polysaccharide (Pdn-BGP NPs) were prepared by using bitter gourd polysaccharide as reducing agent and stabilizing agent. Pd25-BGP NPs had peroxidase-like catalytic property. And the catalytic kinetics of Pd25-BGP NPs towards substrates conformed to the Michaelis-Menten equation. Furthermore, a method was established to detect H2O2 using Pd25-BGP NPs. The linear range and detection limit of this method was 20-320 µM and 2.04 µM, respectively. Finally, Pd25-BGP NPs had good biocompatibility when the concentration was less than 80 µg/mL. The prepared Pd nanoparticles with high stability showed their good prospect in H2O2 detection.


Assuntos
Nanopartículas Metálicas , Momordica charantia , Peroxidase/química , Peróxido de Hidrogênio/química , Nanopartículas Metálicas/química , Polissacarídeos/química , Corantes/química , Colorimetria/métodos
12.
ACS Appl Mater Interfaces ; 14(49): 55201-55216, 2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36458592

RESUMO

Herein, three kinds of molecules were used to modify the surface of platinum nanoparticles (Pt NPs) to tune their surface charge. Zwitterionic thiol-functionalized sulfobetaine (SH-SB) stabilized Pt NPs (SH-SB/Pt NPs) had the highest oxidase activity and peroxidase activity in the prepared platinum nanozymes due to the generation of reactive oxygen species. In addition, a colorimetric dopamine detection method was established based on the peroxidase activity of SH-SB/Pt NPs. This method had a wide range (0-120 µM), a low detection limit (0.244 µM), and high specificity. More importantly, SH-SB/Pt NPs displayed little hemolysis and good stability in the presence of proteins. SH-SB/Pt NPs demonstrated high cytotoxicity in vitro and good antitumor ability in vivo, which was attributed to the photothermal conversion ability of SH-SB/Pt NPs and the generation of reactive oxygen species in the acidic environment. The surface modification of nanozymes using zwitterionic molecules opens a new method to improve the catalytic activity and antitumor ability of nanozymes.


Assuntos
Nanopartículas Metálicas , Platina , Dopamina , Espécies Reativas de Oxigênio , Compostos de Sulfidrila , Peroxidases
14.
ACS Appl Mater Interfaces ; 14(39): 44832-44840, 2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36153950

RESUMO

Flexible conductive polymer composite (CPC) fibers that show large changes in resistance with deformation have recently gained much attention as strain-sensing components for future wearable electronics. However, the electrical resistance of these materials decays with time during dynamic cyclic loading, a deformation performed to simulate their real application as strain sensors. Despite the extensive research on CPC fibers, the mechanism leading to this decay in the electromechanical response under repetitive cycles remains unreported. Herein, this behavior is investigated using fiber-based strain sensors wet spun from thermoplastic polyurethane (TPU) consisting of a carbonaceous hybrid conductive filler system of carbon black (CB) and carbon nanotubes (CNTs). We found electrical viscosity to predict the observed electromechanical resistance decay. This implies that cycling these materials enables the relaxation of both the polymer chains and the conductive network. In addition, the resulting piezoresistive fibers are sensitive to deformation in the region of low strain (gauge factor of 6.0 within 3.0% strain), remain conductive under 280.5% deformation, and are stable for more than 2000 cycles. Finally, we demonstrate the potential of TPU/CB-CNT fibers as strain sensors for monitoring human motion.

15.
Int J Mol Sci ; 23(16)2022 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-36012650

RESUMO

The clustering of transgenes at a chromosome location minimizes the number of segregating loci that needs to be introgressed to field cultivars. Transgenes could be efficiently stacked through site-specific recombination and a recombinase-mediated in planta gene stacking process was described previously in tobacco based on the Mycobacteriophage Bxb1 site-specific integration system. Since this process requires a recombination site in the genome, this work describes the generation of target sites in the Japonica rice genome. Agrobacterium-mediated gene transfer yielded ~4000 random-insertion lines. Seven lines met the criteria of being single copy, not close to a centromere, not inserted within or close to a known gene or repetitive DNA, having precise recombination site sequences on both ends, and able to express the reporter gene. Each target line tested was able to accept the site-specific integration of a new gfp-containing plasmid and in three of those lines, we regenerated fertile plants. These target lines could be used as foundation lines for stacking new traits into Japonica rice.


Assuntos
Oryza , Integrases/genética , Oryza/genética , Plantas Geneticamente Modificadas/genética , Recombinases/genética , Recombinação Genética , Nicotiana/genética , Transgenes
16.
Scanning ; 2022: 4766252, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35822164

RESUMO

In order to explore the effect of comfort care on patients with advanced malignant tumors assisted by bioceramics, 82 patients with advanced malignant tumors admitted to a cancer hospital were selected as the research object control group: 26 males and 15 females and the observation group: 25 males and 16 females. The control group was given routine care, and the observation group was given comfort care on the basis of the control group. The quality of life (QLQ-C30 functional scale) and nursing satisfaction before and after nursing were compared between the two groups. The results of the study indicate that after care, the physical, role, emotional, cognitive, social, general health, and symptom scores of the observation group were significantly higher than those of the control group, the nursing satisfaction degree of the observation group was 97.56%, which was significantly higher than that of the control group of 82.93%, and the difference was statistically significant (P < 0.05). Comfortable care has a definite effect on the care of patients with advanced malignant tumors; it can improve the overall comfort and satisfaction of patients, effectively reduce adverse events, and improve the quality of life of patients.


Assuntos
Neoplasias , Qualidade de Vida , Feminino , Humanos , Masculino , Qualidade de Vida/psicologia
17.
Front Plant Sci ; 13: 898102, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35755656

RESUMO

Wheat has been widely cultivated all over the world. In China, the number of approved wheat varieties has steadily grown since 2010, with the most notable trend in the Huang-Huai-Hai region. Distinctiveness, uniformity, and stability (DUS) are the prerequisites for a new wheat variety to obtain a release permit. Yet, few reports are available on DUS testing characteristics of released wheat varieties. Here, 32 DUS testing characteristics of 195 wheat varieties released in the Huang-Huai-Hai region were investigated to study their artificial selection trend. The results showed that the means, ranges, and coefficients of variation for eight measured characteristics varied greatly, among which the number of sterile spikelets had the largest variation coefficient of all three wheat-growing areas in the Huang-Huai-Hai region. The difference in plant height between the three wheat-growing areas was the most significant. The mean plant height in the northern winter wheat area was the largest, while that in south Huanghuai was the smallest. The released varieties of the three wheat-growing areas in the region had similar artificial selection trends in some characteristics. For instance, flag leaf length and flag leaf width, grain number per ear, and grain volume weight showed an overall upward trend, while the plant height gradually decreased. The clustering results based on DUS testing characteristics showed that artificial selection of characteristics was consistent with ecological adaptation and breeding process as well as pedigree sources. Our findings indicated that with the current breeding objectives, the selection of some non-economic characteristics of wheat varieties, such as awn color, stem color, and glume color, seemed to be able to enrich the genetic diversity of varieties in the Huang-Huai-Hai region. These results could provide guidance for subsequent wheat breeding and production in this region, screening similar varieties, and determining the distinctness of applied varieties in DUS testing.

18.
Theor Appl Genet ; 135(7): 2333-2340, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35596798

RESUMO

KEY MESSAGE: N-cre and C-cre added in separate lines reassemble functional Cre in F1 progeny to excise unnecessary DNA, including cre DNA, thereby eliminating generations needed to cross in and out cre. Crop improvement via transgenesis can benefit through efficient DNA integration strategies. As new traits are developed, new transgenes can be stacked by in planta site-specific integration near previous transgenes, thereby facilitating their introgression to field cultivars as a single segregation locus. However, as each round of integration often requires use of selectable markers, it is more convenient to reuse the selection scheme. The Cre recombinase can be used to delete away previously used selection genes, and other DNA no longer needed after transformation, but the constitutive production of this DNA scanning protein can also affect plant growth. We had previously described in Arabidopsis a split Cre protein fragment complement scheme to reassemble a functional Cre recombinase. As our goal for developing this system was to deploy its use in major crop plants, here we show that Cre protein fragment complementation works in rice with precise recombination structures confirmed by DNA sequencing. As each N-terminal and C-terminal fragment is also flanked by lox recombination sites, they can also self-excise to avoid the need to segregate away the cre DNA. Options to form F1 hybrids homozygous for one transgene, or hemizygous for two different transgenes at the same chromosome location, are discussed.


Assuntos
Arabidopsis , Oryza , Arabidopsis/genética , DNA , Integrases , Oryza/genética , Plantas Geneticamente Modificadas/genética , Recombinação Genética , Transgenes
19.
Theor Appl Genet ; 135(4): 1163-1175, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35325256

RESUMO

KEY MESSAGE: Five soybean target lines with recombinase sites at suitable genomic positions were obtained and tested for site-specific gene stacking. For introgression of new transgenic traits to field cultivars, adding new DNA to an existing transgene locus would reduce the number of segregating loci to reassemble back into a breeding line. We described previously an in planta transgene stacking system using the Bxb1 integrase to direct new DNA into a genomic target, but for this system to operate, the target locus must have a preexisting recombination site for Bxb1-mediated integration. Here, we describe 5 soybean target lines from the screening of 118 Agrobacterium-mediated transgenic plants that were positive for gus expression. Each of the 5 target lines has a single copy of the transgenic DNA with precise DNA sequences of the recombinase recognition sites, located at least 1 kb away from the nearest coding region, not close to the centromere, and showed good expression of the reporter gene. We tested Bxb1 integrase-mediated integration of a gfp-containing plasmid into each of these lines and showed precise site-specific integration in bombarded calluses. For plant regeneration, we used embryonic axes of mature soybean seeds to conduct a new set of biolistic transformation with a DsRed-containing plasmid. Three integration events were regenerated into whole plants, demonstrating the principle that target lines can serve as foundation lines for the stacking of DNA to predefined locations in the soybean genome.


Assuntos
Glycine max , Recombinases , Integrases/genética , Integrases/metabolismo , Melhoramento Vegetal , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Recombinases/genética , Recombinases/metabolismo , Glycine max/genética , Glycine max/metabolismo , Transgenes
20.
Front Plant Sci ; 13: 828960, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35185992

RESUMO

Transgene integration typically takes place in an easy-to-transform laboratory variety before the transformation event is introgressed through backcrosses to elite cultivars. As new traits are added to existing transgenic lines, site-specific integration can stack new transgenes into a previously created transgenic locus. In planta site-specific integration minimizes the number of segregating loci to assemble into a breeding line, but cannot break genetic linkage between the transgenic locus and nearby undesirable traits. In this study, we describe an additional feature of an in planta gene-stacking scheme, in which the Cre (control of recombination) recombinase not only deletes transgenic DNA no longer needed after transformation but also mediates recombination between homologous or non-homologous chromosomes. Although the target site must first be introgressed through conventional breeding, subsequent transgenes inserted into the same locus would be able to use Cre-mediated translocation to expedite a linkage drag-free introgression to field cultivars.

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