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1.
J Exp Bot ; 75(5): 1376-1389, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-37935439

RESUMO

Genomic imprinting refers to allele-specific expression of genes depending on parental origin, and it is regulated by epigenetic modifications. Intraspecific allelic variation for imprinting has been detected; however, the intraspecific genome-wide allelic epigenetic variation in maize and its correlation with imprinting variants remain unclear. Here, three reciprocal hybrids were generated by crossing Zea mays inbred lines CAU5, B73, and Mo17 in order to examine the intraspecific conservation of the imprinted genes in the kernel. The majority of imprinted genes exhibited intraspecific conservation, and these genes also exhibited interspecific conservation (rice, sorghum, and Arabidopsis) and were enriched in some specific pathways. By comparing intraspecific allelic DNA methylation in the endosperm, we found that nearly 15% of DNA methylation existed as allelic variants. The intraspecific whole-genome correlation between DNA methylation and imprinted genes indicated that DNA methylation variants play an important role in imprinting variants. Disruption of two conserved imprinted genes using CRISPR/Cas9 editing resulted in a smaller kernel phenotype. Our results shed light on the intraspecific correlation of DNA methylation variants and variation for imprinting in maize, and show that imprinted genes play an important role in kernel development.


Assuntos
Metilação de DNA , Zea mays , Zea mays/metabolismo , Alelos , Impressão Genômica , Endosperma/genética , Endosperma/metabolismo , Regulação da Expressão Gênica de Plantas
2.
Mol Plant Microbe Interact ; 36(1): 14-25, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36251001

RESUMO

The gray leaf spots caused by Cercospora spp. severely affect the yield and quality of maize. However, the evolutionary relation and pathogenicity variation between species of the Cercospora genus is largely unknown. In this study, we constructed high-quality reference genomes by nanopore sequencing two Cercospora species, namely, C. zeae-maydis and C. zeina, with differing pathogenicity, collected from northeast (Liaoning [LN]) and southeast (Yunnan [YN]) China, respectively. The genome size of C. zeae-maydis-LN is 45.08 Mb, containing 10,839 annotated genes, whereas that of Cercospora zeina-YN is 42.18 Mb, containing 10,867 annotated genes, of which approximately 86.58% are common in the two species. The difference in their genome size is largely attributed to increased long terminal repeat retrotransposons of 3.8 Mb in total length in C. zeae-maydis-LN. There are 41 and 30 carbohydrate-binding gene subfamilies identified in C. zeae-maydis-LN and C. zeina-YN, respectively. A higher number of carbohydrate-binding families found in C. zeae-maydis-LN, and its unique CBM4, CBM37, and CBM66, in particular, may contribute to variation in pathogenicity between the two species, as the carbohydrate-binding genes are known to encode cell wall-degrading enzymes. Moreover, there are 114 and 107 effectors predicted, with 47 and 46 having unique potential pathogenicity in C. zeae-maydis-LN and C. zeina-YN, respectively. Of eight effectors randomly selected for pathogenic testing, five were found to inhibit cell apoptosis induced by Bcl-2-associated X. Taken together, our results provide genomic insights into variation in pathogenicity between C. zeae-maydis and C. zeina. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Ascomicetos , Cercospora , Zea mays/genética , Ascomicetos/genética , Virulência , China , Carboidratos
3.
Int J Mol Sci ; 24(19)2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37834371

RESUMO

Members of the WRKY transcription factor (TF) family are unique to plants and serve as important regulators of diverse physiological processes, including the ability of plants to manage biotic and abiotic stressors. However, the functions of specific WRKY family members in the context of maize responses to fungal pathogens remain poorly understood, particularly in response to Ustilago maydis (DC.) Corda (U. maydis), which is responsible for the devastating disease known as corn smut. A systematic bioinformatic approach was herein employed for the characterization of the maize WRKY TF family, leading to the identification of 120 ZmWRKY genes encoded on 10 chromosomes. Further structural and phylogenetic analyses of these TFs enabled their classification into seven different subgroups. Segmental duplication was established as a major driver of ZmWRKY family expansion in gene duplication analyses, while the Ka/Ks ratio suggested that these ZmWRKY genes had experienced strong purifying selection. When the transcriptional responses of these genes to pathogen inoculation were evaluated, seven U. maydis-inducible ZmWRKY genes were identified, as validated using a quantitative real-time PCR approach. All seven of these WKRY proteins were subsequently tested using a yeast one-hybrid assay approach, which revealed their ability to directly bind the ZmSWEET4b W-box element, thereby controlling the U. maydis-inducible upregulation of ZmSWEET4b. These results suggest that these WRKY TFs can control sugar transport in the context of fungal infection. Overall, these data offer novel insight into the evolution, transcriptional regulation, and functional characteristics of the maize WRKY family, providing a basis for future research aimed at exploring the mechanisms through which these TFs control host plant responses to common smut and other fungal pathogens.


Assuntos
Doenças das Plantas , Ustilago , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Zea mays/genética , Zea mays/microbiologia , Fatores de Transcrição/genética , Ustilago/genética , Filogenia
4.
Int J Mol Sci ; 24(13)2023 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-37445901

RESUMO

The developmental plasticity of the maize inflorescence depends on meristems, which directly affect reproductive potential and yield. However, the molecular roles of upper floral meristem (UFM) and lower floral meristem (LFM) in inflorescence and kernel development have not been fully elucidated. In this study, we characterized the reversed kernel1 (rk1) novel mutant, which contains kernels with giant embryos but shows normal vegetative growth like the wild type (WT). Total RNA was extracted from the inflorescence at three stages for transcriptomic analysis. A total of 250.16-Gb clean reads were generated, and 26,248 unigenes were assembled and annotated. Gene ontology analyses of differentially expressed genes (DEGs) detected in the sexual organ formation stage revealed that cell differentiation, organ development, phytohormonal responses and carbohydrate metabolism were enriched. The DEGs associated with the regulation of phytohormone levels and signaling were mainly expressed, including auxin (IAA), jasmonic acid (JA), gibberellins (GA), and abscisic acid (ABA). The transcriptome, hormone evaluation and immunohistochemistry observation revealed that phytohormone homeostasis were affected in rk1. BSA-Seq and transcriptomic analysis also provide candidate genes to regulate UFM and LFM development. These results provide novel insights for understanding the regulatory mechanism of UFM and LFM development in maize and other plants.


Assuntos
Inflorescência , Reguladores de Crescimento de Plantas , Reguladores de Crescimento de Plantas/metabolismo , Transcriptoma , Zea mays/genética , Zea mays/metabolismo , Perfilação da Expressão Gênica , Homeostase/genética , Regulação da Expressão Gênica de Plantas
5.
Int J Mol Sci ; 23(23)2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36499766

RESUMO

Genomic imprinting is a classic epigenetic phenomenon related to the uniparental expression of genes. Imprinting variability exists in seeds and can contribute to observed parent-of-origin effects on seed development. Here, we conducted allelic expression of the embryo and endosperm from four crosses at 11 days after pollination (DAP). First, the F1 progeny of B73(♀) × Mo17(♂) and the inducer line CAU5 were used as parents to obtain reciprocal crosses of BM-C/C-BM. Additionally, the F1 progeny of Mo17(♀) × B73(♂) and CAU5 were used as parents to obtain reciprocal crosses of MB-C/C-MB. In total, 192 and 181 imprinted genes were identified in the BM-C/C-BM and MB-C/C-MB crosses, respectively. Then, by comparing the allelic expression of these imprinted genes in the reciprocal crosses of B73 and CAU5 (BC/CB), fifty-one Mo17-added non-conserved genes were identified as exhibiting imprinting variability. Fifty-one B73-added non-conserved genes were also identified by comparing the allelic expression of imprinted genes identified in BM-C/C-BM, MB-C/C-MB and MC/CM crosses. Specific Gene Ontology (GO) terms were not enriched in B73-added/Mo17-added non-conserved genes. Interestingly, the imprinting status of these genes was less conserved across other species. The cis-element distribution, tissue expression and subcellular location were similar between the B73-added/Mo17-added conserved and B73-added/Mo17-added non-conserved imprinted genes. Finally, genotypic and phenotypic analysis of one non-conserved gene showed that the mutation and overexpression of this gene may affect embryo and kernel size, which indicates that these non-conserved genes may also play an important role in kernel development. The findings of this study will be helpful for elucidating the imprinting mechanism of genes involved in maize kernel development.


Assuntos
Regulação da Expressão Gênica de Plantas , Zea mays , Zea mays/metabolismo , Endosperma/metabolismo , Impressão Genômica , Sementes/metabolismo
6.
Pestic Biochem Physiol ; 145: 108-117, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29482726

RESUMO

Nicosulfuron is a postemergence herbicide used for weed control in maize fields (Zea mays L.). We used the pair of nearly isogenic inbred lines, SN509-R (nicosulfuron resistant) and SN509-S (nicosulfuron sensitive), to study the effect of nicosulfuron on growth, oxidative stress, and the ascorbate-glutathione (AA-GSH) cycle in waxy maize seedlings. Nicosulfuron treatment was applied when the fourth leaves were fully developed and the obtained effects were compared to water treatment as control. After nicosulfuron treatment, compared to SN509-R, the death of SN509-S might be associated with increased oxidative stress, since higher O2- and H2O2 accumulations were observed in SN509-S. This in turn might have caused severe damage to lipids and proteins, thus reducing membrane stability. These effects were exacerbated with increasing exposure time. After nicosulfuron treatment, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, glutathione reductase, and guaiacol peroxidase of SN509-S were significantly lower than those of SN509-R. Compared to SN509-R, dehydroascorbate content, glutathione (GSH) content, and GSH to glutathione disulphide ratios significantly declined with increasing exposure time in SN509-S. Our results suggest that the rapid degradation of nicosulfuron in SN509-R results in only a small and transient increase in reactive oxygen species (ROS). In contrast, in SN509-S, reduced nicosulfuron degradation leads to increase ROS, while at the same time, the AA-GSH pathway is not activated.


Assuntos
Ácido Ascórbico/metabolismo , Glutationa/metabolismo , Herbicidas/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Piridinas/farmacologia , Compostos de Sulfonilureia/farmacologia , Zea mays/efeitos dos fármacos , Ascorbato Peroxidases/metabolismo , Ácido Desidroascórbico/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos , NADH NADPH Oxirredutases/metabolismo , Oxirredutases/metabolismo , Superóxidos/metabolismo , Zea mays/enzimologia , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
7.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(1): 47-51, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24783531

RESUMO

The structure of coal needs to be understood from a molecular point of view for clean, effective and high value-added utilization of coal. In the literature, molecular structure model of Shendong coal vitrinite (SV) was established by the authors on the basis of experimental results of ultimate analysis and 13C NMR, and the calculated 13C NMR spectrum of SV model was consistent with the experimental spectrum. In order to further verify the accuracy of SV structure model established by the authors, the infrared spectrum of SV structure model was calculated using quantum chemistry semi-empirical VAMP in this thesis. The results showed that the peak shape of calculated IR spectrum of SV structure model was similar to the experiment's, but the wave number of calculated IR spectrum was obviously higher than that of experimental spectrum. According to the calculated results for model compounds by using the same method, calculated vibrational frequency was higher than that of experiment for the same functional groups. Hence, the calculated IR spectrum should be corrected. After correction the calculated IR spectrum of SV structure model matched well with the experimental spectrum. In other words, the SV structure model can truly reflect the structure characteristics of SV.

8.
Waste Manag ; 174: 328-339, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38091657

RESUMO

Co-gasification is crucial for large-scale clean conversion of coal and sludge. In this study, the effects of municipal sewage sludge (MSS, Fe2O3:48.11 %) and pharmaceutical sewage sludge (PSS, Fe2O3: 67.80 %) on ash fusion temperature (AFT) of high AFT Xiangyuan coal (XY) were explored using an AFT analysis, X-ray fluorescence spectrometry, X-ray diffraction, scanning electronic microscopy, and thermodynamics FactSage calculation. The results showed that when MSS or PSS ash mass ratios reached 20 % or 16 % (for XY mixtures, the mass ratio of MSS or PSS should be >5.81 wt% or 5.07 wt%), respectively, the AFT met the requirement of liquid-slag discharge for entrained-flow bed gasification. Under a reducing atmosphere (6:4, CO/CO2, volume ratio), Fe2+ destroyed the bridging-oxygen bonds in the network structure and generated low melting-point (MP) hercynite (FeAl2O4). This resulted in the AFT decreases in the XY mixtures with the additions of PSS or MSS. Meanwhile, the high calcium content (CaO: 13.40 %) easily reacted with Al2O3 and SiO2 and formed anorthite (CaAl2SiO8), which inhibited high-MP mullite formation and decreased the mixed XY AFT. With the increasing SS mass ratio, the surface of the ash sample and thermodynamic FactSage calculation were in good agreement with the experimental results.


Assuntos
Carvão Mineral , Ferro , Esgotos/química , Cinza de Carvão , Temperatura , Dióxido de Silício
9.
ACS Omega ; 8(10): 9067-9073, 2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36936314

RESUMO

To find a simple method to predict the ash flow temperature (FT) based on FactSage calculation, 69 coal ash samples were selected to explore the correlation between the FT and its mineral factor (MF) at a given temperature. An approximate linear relationship was found between ash FT and its MF: FT = 0.64MF + 1332, with a related coefficient value of 0.94 and a standard deviation of 25.77 °C. Ten ash samples were used to investigate its reliability. The calculated FTs were consistent with experimental FTs in the error range of measurement, and the correlation might be more reliable for low iron and low calcium coal.

10.
PeerJ ; 11: e15819, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37810777

RESUMO

Background: Maize is sensitive to salt stress, especially during the germination and seedling stages. Methods: We conducted germination experiments on 60 maize materials under salt stress, and screened out the most salt-tolerant and salt-sensitive varieties based on germination indicators. Afterwards, transcriptome analysis was performed to screen for key regulators in the plumule and flag leaf at the germination and seedling stages, respectively. Following that, transgenic tobacco was developed to expose the roles and mechanisms of the candidate genes, enabling a deeper investigation of their functions. Results: Out of the 60 inbred lines of maize, "975-12" exhibits the highest level of salt tolerance, while "GEMS64" displays the lowest. The application of salt stress resulted in a significant increase in the levels of antioxidant enzymes in both "975-12" and "GEMS64". ABA signal transduction and jasmonic acid pathways were the pathways that mainly affected by salt stress. In addition, a significant finding has been made indicating that when exposed to high levels of salt stress, the expression of ZmHSP90 in '975-12' increased while in 'GEMS64' decreased. Furthermore, in tobacco plants overexpressing ZmHSP90, there was an increase in antioxidant enzyme activity associated with salt tolerance. ZmHSP90 enhanced the expression levels of NtSOS1, NtHKT1, and NtNHX1 as compared to those in the salt treatment, causing the maintenance of Na+ and K+ homeostasis, suggesting that high expression of ZmHSP90 was conducive to regulate Na+ transporters to maintain K+/Na+ balanced in tobacco.


Assuntos
Antioxidantes , Zea mays , Antioxidantes/metabolismo , Zea mays/genética , Plantas Geneticamente Modificadas/genética , Germinação/genética , Plântula/genética , Tolerância ao Sal/genética
11.
Front Plant Sci ; 14: 1128780, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36875610

RESUMO

Gibberellin (GA) is an important endogenous hormone involved in plant responses to abiotic stresses. Experiments were conducted at the Research and Education Center of Agronomy, Shenyang Agricultural University (Shenyang, China) in 2021.We used a pair of near-isogenic inbred maize lines comprising, SN98A (light-sensitive inbred line) and SN98B (light-insensitive inbred line) to study the effects of exogenous gibberellin A3 (GA3) application on different light-sensitive inbred lines under weak light conditions. The concentration of GA3 was selected as 20, 40 and 60 mg L-1. After shade treatment, the photosynthetic physiological indexes of SN98A were always lower than SN98B, and the net photosynthetic rate of SN98A was 10.12% lower than SN98B on the 20th day after shade treatment. GA3 treatments significantly reduced the barren stalk ratios in SN98A and improved its seed setting rates by increasing the net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), photosynthetic pigment contents, photochemical efficiency of photosystem II (PS II) (Fv/Fm), photochemical quenching coefficient (qP), effective quantum yield of PSII photochemistry (ΦPSII), and antioxidant enzyme activities, where the most effective treatment was 60 mg L-1GA3. Compared with CK group, the seed setting rate increased by 33.87%. GA3 treatment also regulated the metabolism of reactive oxygen species (ROS) and reduced the superoxide anion ( O 2 - ) production rate, H2O2 content, and malondialdehyde content. The superoxide anion ( O 2 - ) production rate, H2O2 content and malondialdehyde content of SN98A sprayed with 60 mg L-1 GA3 decreased by 17.32%,10.44% and 50.33% compared with CK group, respectively. Compared with the control, GA3 treatment significantly (P < 0.05) increased the expression levels of APX and GR in SN98A, and APX, Fe-SOD, and GR in SN98B. Weak light stress decreased the expression of GA20ox2, which was related to gibberellin synthesis, and the endogenous gibberellin synthesis of SN98A. Weak light stress accelerated leaf senescence, and exogenous GA3 application inhibited the ROS levels in the leaves and maintained normal physiological functions in the leaves. These results indicate that exogenous GA3 enhances the adaptability of plants to low light stress by regulating photosynthesis, ROS metabolism and protection mechanisms, as well as the expression of key genes, which may be an economical and environmentally friendly method to solve the low light stress problem in maize production.

12.
Front Neurosci ; 17: 1149767, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37113154

RESUMO

Background: Although endovascular mechanical thrombectomy demonstrates clinical efficacy in posterior circulation acute ischemic stroke (AIS), only one third of these patients attain functional independence with a third of patients' expiring despite vascular recanalization. Neuroprotection strategies, such as therapeutic hypothermia (TH) have been considered a promising adjunctive treatment in AIS. We propose the following rationale, design and protocol for a prospective randomized controlled trial (RCT) aimed to determine whether Vertebrobasilar Artery Cooling Infusion (VACI) improves functional outcomes in posterior circulation AIS patients post mechanical thrombectomy. Methods: Subjects in the study will be assigned randomly to either the cooling infusion or the control group in a 1:1 ratio (n = 40). Patients allocated to the cooling infusion group will receive 300 ml cool saline at 4C through the catheter (30 ml/min) into vertebral artery after thrombectomy. The control group will receive the same volume of 37C saline. All patients enrolled will receive standard care according to current guidelines for stroke management. The primary outcome is symptomatic intracranial hemorrhage (ICH), whereas the secondary outcomes include functional outcome score, infarction volume, mortality, ICH, fatal ICH, cerebral vasospasm, coagulation abnormality, pneumonia and urinary infection. Discussions: This study will determine the preliminary safety, feasibility, and neuroprotective benefits of VACI in posterior circulation AIS patients with reperfusion therapy. The results of this study may provide evidence for VACI as a new therapy in posterior circulation AIS. Clinical Trial Registration: www.chictr.org.cn, ChiCTR2200065806, registered on November 15, 2022.

13.
Front Plant Sci ; 14: 1280331, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37964997

RESUMO

Introduction: Climate changes pose a significant threat to crop adaptation and production. Dissecting the genetic basis of phenotypic plasticity and uncovering the responsiveness of regulatory genes to environmental factors can significantly contribute to the improvement of climate- resilience in crops. Methods: We established a BC1F3:4 population using the elite inbred lines Zheng58 and PH4CV and evaluated plant height (PH) across four environments characterized by substantial variations in environmental factors. Then, we quantified the correlation between the environmental mean of PH (the mean performance in each environment) and the environmental parameters within a specific growth window. Furthermore, we performed GWAS analysis of phenotypic plasticity, and identified QTLs and candidate gene that respond to key environment index. After that, we constructed the coexpression network involving the candidate gene, and performed selective sweep analysis of the candidate gene. Results: We found that the environmental parameters demonstrated substantial variation across the environments, and genotype by environment interaction contributed to the variations of PH. Then, we identified PTT(35-48) (PTT is the abbreviation for photothermal units), the mean PTT from 35 to 48 days after planting, as the pivotal environmental index that closely correlated with environmental mean of PH. Leveraging the slopes of the response of PH to both the environmental mean and PTT(35-48), we successfully pinpointed QTLs for phenotypic plasticity on chromosomes 1 and 2. Notably, the PH4CV genotypes at these two QTLs exhibited positive contributions to phenotypic plasticity. Furthermore, our analysis demonstrated a direct correlation between the additive effects of each QTL and PTT(35-48). By analyzing transcriptome data of the parental lines in two environments, we found that the 1009 genes responding to PTT(35-48) were enriched in the biological processes related to environmental sensitivity. BBX6 was the prime candidate gene among the 13 genes in the two QTL regions. The coexpression network of BBX6 contained other genes related to flowering time and photoperiod sensitivity. Our investigation, including selective sweep analysis and genetic differentiation analysis, suggested that BBX6 underwent selection during maize domestication. Discussion: Th is research substantially advances our understanding of critical environmental factors influencing maize adaptation while simultaneously provides an invaluable gene resource for the development of climate-resilient maize hybrid varieties.

14.
ACS Omega ; 8(9): 8201-8209, 2023 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-36910948

RESUMO

A middle/low-temperature coal tar (M/LTCT) was obtained from a low-temperature carbonization plant in Shaanxi, China. The M/LTCT was separated into light components and coal tar pitch through extraction. A series of alkanes, aromatic hydrocarbons, oxygen-containing arenes (OCAs), and nitrogen-containing arenes were fractionated from light components by medium-pressure preparative chromatography with gradient elution using petroleum ether and ethyl acetate. They were analyzed using a gas chromatography-mass spectrometer (GC-MS) and a Fourier transform infrared spectrometer. The OCAs were analyzed by a Fourier transform Orbitrap MS (quadrupole exactive Orbitrap mass spectrometer), and the molecular distribution of the O 1-O 6 species was studied. OCAs are mainly oxygen-containing aromatic compounds, including aromatic phenols, furans, alkoxy aromatic hydrocarbons, aromatic ethers, aromatic aldehydes, aromatic ketones, and aromatic acids. The position of the oxygen atom on the aromatic ring and the condensation form of the aromatic ring are studied.

15.
Plants (Basel) ; 12(19)2023 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-37836236

RESUMO

Dry direct seeding rice (DSR) is an emerging production system because of increasing labor and water scarcity in rice cultivation. The limited availability of rice cultivars suitable for dry direct seeding hampers the widespread adoption of this cultivation method in Northeast China. This study aimed to investigate grain production and plant characteristics associated with dry direct seeding rice. We conducted a field experiment on 79 japonica rice cultivars in Shenyang City, Liaoning Province, Northeast China, in 2020 and 2021. This study found that the grain yield of the tested rice cultivars ranged from 5.75-11.00 t ha-1, with a growth duration lasting between 144-161 days across the cultivars. These cultivars were then categorized into high yielding (HY), medium yielding (MY), and low yielding (LY) based on daily yield by using Ward's hierarchical clustering method. The higher grain yield for HY compared to MY and LY was attributed to more spikelets per unit area. The HY alleviated the conflict between higher panicle density and larger panicle size by improving the seedling emergence rate and productive stem rate. It also significantly increased shoot biomass at maturity. The HY reduced the period between seeding and beginning of heading (BBCH 51) and the proportion of dry matter partitioned to the leaf at the heading stage. However, it also increased the accumulation of dry matter in the grain and the proportion of dry matter partitioned to the grain at maturity. Furthermore, the HY markedly increased the harvest index and grain-leaf ratio, which are beneficial to coordinate the source-sink relationship. A quadratic function predicted that 98 days is the optimum growth duration before heading (BBCH 51) for achieving maximum yield. In conclusion, for dry direct seeding rice, it is appropriate to select high-yielding japonica inbred rice cultivars with shorter growth duration before heading (about 93-102 day), higher panicle number (about 450-500 × 104 ha-1), more spikelet number per panicle (about 110-130), higher seedling emergence rate (about 70-75%), higher productive stem rate (about 60-70%), and greater harvest index (about 50-55%).

16.
Front Plant Sci ; 13: 892055, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35481149

RESUMO

Maize (Zea mays) doubled haploid (DH) breeding is a technology that can efficiently generate inbred lines with homozygous genetic backgrounds. Haploids are usually produced through in vivo induction by haploid inducer lines in maize. Currently, two approaches are usually used to develop maize haploid inducer lines. One is through the conventional breeding improvement based on the Stock6 germplasm, and this strategy is extensively used to induce maternal haploids in commercial maize DH breeding. Another strategy, newly developed but less utilized so far, is by genetic manipulation of the Centromeric Histone3 (CENH3) in regular lines. However, whether both approaches can be combined to develop the haploid inducer line with higher maternal haploid induction rate (HIR) has not been reported. In this study, we manipulated the Stock6-derived inducer lines by overexpressing maize CENH3 fused with different fluorescent protein tags and found that the engineered Stock6-derived lines showed an obvious increase in the maternal HIR. Intriguingly, this above strategy could be further improved by substituting a tail-altered CENH3 for the full-length CENH3 in the tagged expression cassette, resulting in a maternal HIR up to 16.3% that was increased by ~6.1% than Stock6-derived lines control. These results suggested that integration of two in vivo haploid induction methods could rapidly and effectively improve the maternal HIRs of maize Stock6-derived inducer lines, and provided a potentially feasible solution for further optimizing the process of commercial maize DH breeding.

17.
ACS Omega ; 7(12): 10588-10598, 2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35382334

RESUMO

Co-gasification with coal provides an economically viable way to use sludge. To investigate the effect of municipal sludge (MS) on the sintering behaviors of low-rank coals (LRCs) and their modification mechanisms, the initial sintering temperature (T s) of three LRCs and their mixtures with MS addition were tested by a T s analyzer, an X-ray diffractometer, and FactSage calculation. The results show that the T s values of Xiaolongtan coal (XLT), Xiangyuan coal (XY), and Daliuta coal (DLT) all increase with MS addition. The 9-12% MS mass ratio is suitable during LRC fluidized-bed gasification to mitigate ash-related issues. The T s is closely related to the liquid-phase content or the transmissions of microparticles (e.g., atoms and ions) or blank spots during heating, while the ash fusion temperatures (AFTs) are mainly determined by acid/base ratios. The T s values of high-Fe XLT and XY mixed ashes increased gradually with increasing MS proportion because the sintering mechanisms transferred from liquid phase to solid phase, while for relatively high-Mg DLT ashes, the T s values increased with increasing MS proportions, which might result from the formations of high-melting-point minerals (e.g., Ca3(PO4)2 and Mg2SiO4). The results deepen the understanding of ash sintering behaviors and provide references to alleviate ash-related issues during gasification.

18.
Front Neurol ; 13: 981498, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36457864

RESUMO

Objective: Rehabilitation is essential in reducing stroke disability and should be performed as early as possible. Exercise is an established and effective rehabilitation method; however, its implementation has been limited as its very early use exacerbates cerebral injury and is restricted by patients' unstable conditions and disabilities. Remote ischemic conditioning (RIC) is a passive and accessible therapy in acute phases of stroke and appears to have similar neuroprotective effects as exercise. This study assessed the safety and feasibility of the novel rehabilitation strategy-early RIC followed by exercise (RICE) in acute ischemic stroke (AIS). Methods: We conducted a single-center, double-blinded, randomized controlled trial with AIS patients within 24 h of stroke onset or symptom exacerbation. All enrolled patients were randomly assigned, at a ratio of 1:1, to either the RICE group or the sham-RICE group (sham RIC with exercise). Each group received either RIC or sham RIC within 24 h after stroke onset or symptom exacerbation, once a day, for 14 days. Both groups started the exercise routine on day 4, twice daily, for 11 total days. The safety endpoints included clinical deterioration, recurrence of stroke, hemorrhagic transformation, complications, and adverse events resulting from RICE during hospitalization. The efficacy endpoints [Modified Rankin Scale (mRS) score, National Institutes of Health Stroke Scale (NIHSS) score, Barthel Index, and walking ability] were evaluated at admission and 90 days after stroke onset. Results: Forty AIS patients were recruited and completed the study. No significant differences in baseline characteristics were found between the two groups, which included risk factors, stroke severity at admission, pre-morbid disability, and other special treatments. No significant differences were found in the safety endpoints between two groups. Excellent recovery (mRS 0-2) at 3 months was obtained in 55% of the patients with RICE as compared 40% in sham group, but it did not reach a significant level. Conclusions: RICE was safe and feasible for AIS patients, and seems to be a promising early stroke rehabilitation. The results of this study suggest a need for a future randomized and controlled multicenter trial with a larger sample size to determine the efficacy of RICE.

19.
Front Plant Sci ; 12: 680376, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34539688

RESUMO

The synthetic cytokinin 6-benzyladenine (6-BA) regulates plant growth and prevents the negative consequences of various forms of abiotic stress, including waterlogging in crop plants. The present study aimed to investigate the effects of exogenous 6-BA on the growth, oxidative stress, and ascorbate-glutathione (AsA-GSH) cycle system in the inbred SY-MY13 (waterlogging-resistant) and SY-XT1 (waterlogging-sensitive) seedlings of waxy corn in conditions of waterlogging stress. The results demonstrated that waterlogging stress causes chlorosis and necrosis in waxy corn leaves, inhibiting growth and leading to the accumulation of reactive oxygen species (ROS), which induces oxidative stress and, in turn, reduces membrane lipid peroxidation and the disruption of membrane homeostasis. This is specifically manifested in the increased concentrations of superoxide anion radicals ( O 2 - ), hydrogen peroxide (H2O2), and malondialdehyde (MDA), in addition to increased relative electrical conductivity (REC%) values. The SY-MY13 strain exhibited growth superior to that of SY-XT1 when waterlogged due to its excellent waterlogging resistance. Thus, exogenous 6-BA was found to be effective in enhancing the growth of plants stressed by waterlogging in terms of the weight of the shoots and roots, shoot height, and leaf area. In addition to this, exogenous 6-BA also reduced the accumulation of O 2 - , H2O2, and MDA, increased ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR), and monodehydroascorbate reductase (MDHAR) activity, and enhanced ascorbic acid (AsA), and reduced glutathione (GSH) concentration through the regulation of the efficiency of the AsA-GSH cycle system in maize plants. Hence, the application of exogenous 6-BA can alleviate waterlogging-induced damage and improve waterlogging tolerance in waxy corn via the activation of the AsA-GSH cycle system and the elimination of ROS.

20.
Environ Sci Pollut Res Int ; 28(15): 19298-19309, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33394398

RESUMO

Acetochlor is always used in maize (Zea mays L.) fields as a common pre-emergence herbicide. In this field study, we investigated the effects of acetochlor on the photosynthetic characteristics, chlorophyll fluorescence parameters, and antioxidant enzyme activities in acetochlor-resistant (BWC95) and acetochlor-sensitive (BWC12) near-isogenic lines. We sprayed acetochlor after sowing, using water treatment as the control. After spraying acetochlor, the net photosynthetic rate, stomatal conductance, transpiration rate, and the function of chloroplasts were significantly lower in BWC12 than BWC95, whereas the intercellular CO2 concentrations and stomatal limitation values were higher. In addition to nonphotochemical quenching, chlorophyll fluorescence measurements obtained using leaves showed that the maximum photochemical efficiency of photosystem II (PSII), actual photochemical efficiency of PSII, photochemical quenching of chlorophyll fluorescence, and electron transport rate were higher in BWC95 than BWC12 after acetochlor treatment. H2O2 and O2˙- levels were higher in BWC12 than BWC95, which resulted in severe membrane lipid peroxidation due to sustained oxidative stress. Thus, the malondialdehyde content increased significantly with the exposure time in BWC12, and the antioxidant enzyme activities were lower in BWC12 than BWC95. The results show that acetochlor resistance is directly related to a high photosynthetic rate and a protective antioxidant enzyme system.


Assuntos
Clorofila , Zea mays , Peróxido de Hidrogênio , Fotossíntese , Complexo de Proteína do Fotossistema II/metabolismo , Folhas de Planta/metabolismo , Toluidinas , Ceras , Zea mays/metabolismo
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