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1.
J Infect Dis ; 2020 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-32437567

RESUMO

BACKGROUND AND AIMS: Long-term nucleos(t)ide analogues (NAs) treatment can reverse liver fibrosis in chronic hepatitis B (CHB), but its effect on fibrosis regression remains limited. Biejia-Ruangan (BR) has been approved in China as an anti-fibrotic traditional Chinese medicine drug in patients with chronic liver diseases. A multicenter randomized controlled trial aims to evaluate the effect of BR on fibrosis regression in CHB patients treated with NAs. METHODS: CHB patients with histologically confirmed advanced fibrosis or cirrhosis were randomly assigned to receive entecavir (ETV) (0.5mg per day) plus BR (2g three times a day) or placebo for 72 weeks. Liver fibrosis regression was defined as a reduction of ≥1 point by the Ishak Fibrosis Stage (IFS). RESULTS: Overall, 500 patients were enrolled in each group as the intention-to-treat population. The rate of fibrosis regression after 72 week treatment was significantly higher in ETV+BR group (40% versus 31.8%, P=0.0069). Among 388 patients with cirrhosis (i.e., IFS ≥5) at baseline, the rate of cirrhosis reversal (i.e., IFS ≤4) was significantly higher in ETV+BR group (41.5% versus 30.7%, P=0.0103). CONCLUSIONS: Addition of BR to the current standard treatment with NAs in CHB patients with advanced fibrosis or cirrhosis can improve liver fibrosis regression.

2.
J Virol ; 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32295908

RESUMO

HIV-1 envelope (Env) trimers, stabilized in a prefusion-closed conformation, can elicit humoral responses capable of neutralizing HIV-1 strains closely matched in sequence to the immunizing strain. One strategy to increase elicited neutralization breadth involves vaccine priming of immune responses against a target site of vulnerability followed by vaccine boosting of these responses with prefusion-closed Env trimers. This strategy has succeeded at the fusion peptide (FP)-site of vulnerability in eliciting cross-clade neutralizing responses in standard vaccine-test animals. However, the breadth and potency of the elicited responses have been less than optimal. Here we identify three mutations (3mut) - Met302, Leu320, and Pro329 - that stabilize the apex of the Env trimer in a prefusion-closed conformation and show antigenically, structurally and immunogenically that combining 3mut with other approaches (e.g. repair-and-stabilize and glycine-helix breaking) yields well-behaved clade C-Env trimers capable of boosting the breadth of FP-directed responses. Crystal structures of these trimers confirmed prefusion-closed apexes stabilized by hydrophobic patches contributed by Met302 and Leu320, with Pro329 assuming canonically restricted dihedral angles. We substituted the N-terminal eight residues of FP (FP8, residues 512-519) of these trimers with the second most prevalent FP8 sequence (FP8v2, AVGLGAVF), and observed a 3mut-stabilized consensus clade C-Env trimer with FP8v2 to boost the breadth elicited in guinea pigs of FP-directed responses induced by immunogens containing the most prevalent FP8 sequence (FP8v1, AVGIGAVF). Overall, 3mut can stabilize the Env-trimer apex, and the resultant apex-stabilized Env trimers can be used to expand the neutralization breadth elicited against the FP-site of vulnerability.IMPORTANCE A major hurdle to the development of an effective HIV-1 vaccine is the elicitation of serum responses capable of neutralizing circulating strains of HIV, which are extraordinarily diverse in sequence and often highly neutralization resistant. Recently, we showed how sera with 20-30% neutralization breadth could, nevertheless, be elicited in standard vaccine-test animals by priming with the most prevalent N-terminal 8 residues of the HIV-1 fusion peptide (FP8) followed by boosting with a stabilized BG505-envelope (Env) trimer. Here we show that subsequent boosting with a '3mut' apex-stabilized consensus C-Env trimer, modified to have the second most prevalent FP8 sequence, elicits higher neutralization breadth than induced by continued boosting with the stabilized BG505-Env trimer. With increased neutralizing breadth elicited by boosting with a heterologous trimer containing the second most prevalent FP8 sequence, the fusion peptide-directed immune-focusing approach moves a step closer toward realizing an effective HIV-1 vaccine regimen.

3.
Cell Rep ; 31(1): 107488, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32268107

RESUMO

Antibodies targeting the V1V2 apex of the HIV-1 envelope (Env) trimer comprise one of the most commonly elicited categories of broadly neutralizing antibodies. Structures of these antibodies indicate diverse modes of Env recognition typified by antibodies of the PG9 class and the PGT145 class. The mode of recognition, however, has been unclear for the most potent of the V1V2 apex-targeting antibodies, CAP256-VRC26.25 (named for donor-lineage.clone and referred to hereafter as VRC26.25). Here, we determine the cryoelectron microscopy structure at 3.7 Å resolution of the antigen-binding fragment of VRC26.25 in complex with the Env trimer thought to have initiated the lineage. The 36-residue protruding loop of VRC26.25 displays recognition incorporating both strand-C interactions similar to the PG9 class and V1V2 apex insertion similar to the PGT145 class. Structural elements of separate antibody classes can thus intermingle to form a "combined" class, which in this case yields an antibody of extraordinary potency.

4.
J Exp Bot ; 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-32309855

RESUMO

Natural selection drives local adaptations of species to biotic or abiotic environmental stresses. As a result, adaptive phenotypic divergence can evolve among related species living in different habitats. However, the genetic foundation of this divergence process remains largely unknown. Two closely related alpine grass species, Stipa capillacea and Stipa purpurea, are distributed in different rainfall regions of northern Tibet. Here, we analyzed the drought tolerance of these two closely related Stipa species, and S. purpurea showed more resistance to drought stress than S. capillacea. To further understand the genetic diversity behind their adaptation to drought environments, a comprehensive gene repertoire was generated using PacBio isoform and Illumina RNA sequencing technologies. Bioinformatics analyses revealed that differential transcripts were mainly enriched in the wax synthetic pathway, and a threonine residue at position 239 of WSD1 was identified as having undergone positive selection in S. purpurea. Using heterologous expression in the Saccharomyces cerevisiae mutant H1246, site-directed mutagenesis studies demonstrated a positive-selection site result in changes to the wax esters profile. This difference may play an important role in S. purpurea in response to drought conditions, indicating that S. purpurea has evolved specific strategies involving its wax biosynthetic pathway as part of its long-term adaptation to the QTP.

5.
Adv Mater ; 32(14): e1905578, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32101356

RESUMO

The rate-determining process for electrochemical energy storage is largely determined by ion transport occurring in the electrode materials. Apart from decreasing the distance of ion diffusion, the enhancement of ionic mobility is crucial for ion transport. Here, a localized electron enhanced ion transport mechanism to promote ion mobility for ultrafast energy storage is proposed. Theoretical calculations and analysis reveal that highly localized electrons can be induced by intrinsic defects, and the migration barrier of ions can be obviously reduced. Consistently, experiment results reveal that this mechanism leads to an enhancement of Li/Na ion diffusivity by two orders of magnitude. At high mass loading of 10 mg cm-2 and high rate of 10C, a reversible energy storage capacity up to 190 mAh g-1 is achieved, which is ten times greater than achievable by commercial crystals with comparable dimensions.

6.
Medicine (Baltimore) ; 99(7): e19065, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32049806

RESUMO

The objective of this paper is to demonstrate, considering the experiences from Chinese people, if slow transit constipation (STC) can be accurately diagnosed, choosing patients qualifying for surgery, subtotal colectomy with antiperistaltic cecosigmoidal anastomosis (STC-Anti-CSA) may come with more acceptable short and long-term outcomes.A retrospective study was performed at a department of colorectal and anal surgery. A cohort of 29 patients were coming with up to 5 years' follow-up care, who were in a diverse range of age, BMI, laxative medicine histories, including both males and females. Pre-surgery work-up strictly followed a protocol designed to rule out the patients who were not suitable for surgery treatments. Classification of STC was followed after diagnosis. STC-Anti-CSA was performed in all cases. The operative time, blood loss, average post-operative length of stay (LOS), frequency of BMs, stool consistency and patients satisfaction, by using Wexner constipation score (WCS), numerical rating scale (NRS), and abdominal bloating score (ABS), over the study period were recorded.In this study, there were 14 males and 15 females, with mean age 51, and BMI from 20.14 to 31.62 kg/m. The period of laxative medicine history was 4.8 years (2-13 years). The mean operative time was 152 ±â€Š34 min, and the mean perioperative blood loss was 123 ±â€Š51 mL. Average post-operative LOS (LOS) was 8 days. There were no severe post-operative complications, peri-operative mortality, anastomotic leaks, or revisions of the original surgery. Initial post-operative BMs averaged 6 times/day. During the period of 1 month to 12 months follow-up care, BMs fell down to 2 or 3 times/day. By the 1st to 3rd year follow-up care, BMs averaged 5 to 7 times/week. However, from the 4th year to 5th year, constipations recurred somehow. However, most patients were satisfied with their bowel patterns.STC-Anti-CSA can receive acceptable postoperative outcomes as long as the patients can be accurately diagnosed and classified as severe STC. Among the surgical procedures for STC, this procedure may be another suitable option, especially for Chinese people.


Assuntos
Ceco/cirurgia , Constipação Intestinal/cirurgia , Reto/cirurgia , Adulto , Idoso , Anastomose Cirúrgica , China , Colectomia , Feminino , Trânsito Gastrointestinal , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Qualidade de Vida , Estudos Retrospectivos , Resultado do Tratamento
7.
Int Wound J ; 17(3): 555-561, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31975537

RESUMO

Sacrococcygeal pilonidal sinus is one of common diseases in general department. However, it is characterised, for surgeons, by high post-surgical recurrence and high incidence of post-surgical wound complications. Due to that fact, this retrospective randomised clinical study was designed to evaluate the surgical procedure effect of Z-plasty (ZP), compared with convention simple excision (SE). A total of 67 patients from May 2015 to May 2019 in our department were studied into two groups randomly, the group of ZP and the group of SE. The patients' characteristics, surgical data, hospital length of stay (LOS), and post-surgery complications were recorded. Statistical approaches were proceed with P-value analysis. The results are as follows. No significant differences were found between these two groups of the ages, gender distribution, Body Mass Index (BMI), smoking history, diabetes mellitus, and blood hypertension. The estimated blood loss, specimen volume, distance to anus, and drain output on the first day of post-surgery between the two groups were not statistically significant, either. However, surgical time in the ZP group was longer than that in the SE group (P < .0001). LOS in the ZP group was obviously shorter than that in the SE group (P = .0051). Furthermore, the patients of the ZP group were tending to suffer from fewer post-surgical complications than the ones of the SE group. In a conclusion, we hold the point view that the surgical procedure of ZP can lead a better outcome than SE because it demonstrated shortened LOS and fewer post-surgical complications.

8.
ISME J ; 14(4): 931-944, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31896789

RESUMO

Although biodiversity and ecosystem functions are strongly shaped by contemporary environments, such as climate and local biotic and abiotic attributes, relatively little is known about how they depend on long-term geological processes. Here, along a 3000-m elevational gradient with tectonic faults on the Tibetan Plateau (that is, Galongla Mountain in Medog County, China), we study the joint effects of geological and contemporary environments on biological communities, such as the diversity and community composition of plants and soil bacteria, and ecosystem functions. We find that these biological communities and ecosystem functions generally show consistent elevational breakpoints at 2000-2800 m, which coincide with Indus-Yalu suture zone fault and are similar to the elevational breakpoints of soil bacteria on another mountain range 1000 km away. Mean annual temperature, soil pH and moisture are the primary contemporary determinants of biodiversity and ecosystem functions, which support previous findings. However, compared with the models excluding geological processes, inclusion of geological effects, such as parent rock and weathering, increases 67.9 and 35.9% of the explained variations in plant and bacterial communities, respectively. Such inclusion increases 27.6% of the explained variations in ecosystem functions. The geological processes thus provide additional links to ecosystem properties, which are prominent but show divergent effects on biodiversity and ecosystem functions: parent rock and weathering exert considerable direct effects on biodiversity, whereas indirectly influence ecosystem functions via interactions with biodiversity and contemporary environments. Thus, the integration of geological processes with environmental gradients could enhance our understanding of biodiversity and, ultimately, ecosystem functioning across different climatic zones.

9.
J Sci Food Agric ; 100(3): 1064-1071, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31713870

RESUMO

BACKGROUND: Glucosinolates (GSLs) are secondary metabolites, mainly existing in Brassica vegetables. Their breakdown products have health benefits and contribute to the distinctive taste of these vegetables. Because of their high value, there is a lot of interest in developing breeding strategies to increase the content of beneficial GSLs in Brassica species. GSLs are synthesized from certain amino acids and their biological roles depend largely on the structure of their side chains. Flavin-containing monooxygenase (FMOGS-OX ) genes are involved in the synthesis of these side chains. To better understand GSL biosynthesis, we sequenced the transcriptomes of turnip (Brassica rapa var. rapa) tubers at four developmental stages (S1-S4) and determined their GSL content. RESULTS: The total GSL content was high at the early stage (S1) of tuber development and increased up to S3, then decreased at S4. We detected 61 differentially expressed genes, including five FMOGS-OX genes, that were related for GSL biosynthesis among the four developmental stages. Most of these genes were highly expressed at stages S1 to S3, but their expression was much lower at S4. We estimated the effect of the five FMOGS-OX genes on GSL content by overexpressing them in turnip hairy roots and found that the amount of aliphatic GSLs increased significantly in the transgenic plants. CONCLUSION: The transcriptome data and characterization of genes involved in GSL biosynthesis, particularly the FMOGS-OX genes, will be valuable for improving the yield of beneficial GSLs in turnip and other Brassica crops. © 2019 Society of Chemical Industry.


Assuntos
Brassica rapa/enzimologia , Brassica rapa/crescimento & desenvolvimento , Glucosinolatos/biossíntese , Oxigenases de Função Mista/metabolismo , Proteínas de Plantas/metabolismo , Vias Biossintéticas , Brassica rapa/genética , Brassica rapa/metabolismo , Dinitrocresóis/metabolismo , Regulação da Expressão Gênica de Plantas , Oxigenases de Função Mista/genética , Proteínas de Plantas/genética , Raízes de Plantas/enzimologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Transcriptoma
10.
Cancer Manag Res ; 11: 10093-10106, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31819642

RESUMO

Background: Colorectal cancers (CRC) are one of the most common forms of cancer seen worldwide, and also remain difficult to treat despite recent advances in chemotherapy. Although significant progress has been made in recent years towards precision medicine and mutation-guided therapy, common mechanisms that underlie tumor growth and progression remain incompletely understood. Methods: Tumor tissue and nearby unaffected tissue were collected from >15 patients at each stage of CRC, from which we generated representative proteomics profiles of three stages. Bioinformatics analysis was performed to discover common differences that may be shared between the representative profiles and across larger cohorts. Flow cytometry was then used to identify functional consequences of SSBP1 depletion in cell lines, since its expression level was consistently increased in tumor cells across all of the datasets analyzed. Results: Direct comparison of CRC tumor and unaffected tissue at each stage demonstrated that a number of proteins involved in mitochondrial function displayed significantly altered expression patterns. Depletion of SSBP1 in colon cancer cell lines was able to trigger loss of mitochondrial mass and an increase in tumor cell death, and this effect that was further accentuated in the presence of the common chemotherapy drug cisplatin. Conclusion: Mitochondrial biogenesis and maintenance may play an important part in tumor cell survival during CRC progression, and may be a useful target for directed inhibition or adjuvant targeting in the cases of cisplatin resistance.

11.
Nat Commun ; 10(1): 5230, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31745089

RESUMO

The Hengduan Mountains (HDM) biodiversity hotspot exhibits exceptional alpine plant diversity. Here, we investigate factors driving intraspecific divergence within a HDM alpine species Salix brachista (Cushion willow), a common component of subnival assemblages. We produce a high-quality genome assembly for this species and characterize its genetic diversity, population structure and pattern of evolution by resequencing individuals collected across its distribution. We detect population divergence that has been shaped by a landscape of isolated sky island-like habitats displaying strong environmental heterogeneity across elevational gradients, combined with population size fluctuations that have occurred since approximately the late Miocene. These factors are likely important drivers of intraspecific divergence within Cushion willow and possibly other alpine plants with a similar distribution. Since intraspecific divergence is often the first step toward speciation, the same factors can be important contributors to the high alpine species diversity in the HDM.

12.
Plant Methods ; 15: 115, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31636692

RESUMO

Background: In situ hybridization (ISH) is a general molecular biological technique used to determine the spatiotemporal expression of genes in many species. In the past few years, numerous ISH protocols have been established in many species. Turnip (Brassica rapa var. rapa) is an important crop in the world, especially in the Plateau area of China, and is a traditional Tibetan medicine. However, ISH protocol in turnip has not been established. Results: We explored and established an optimal workflow for mRNA ISH system for turnip which has been evaluated using BrrCLV3 and BrrWUSa. The optimal methods include: (1) fixation method, (2) protease K pretreatment time, (3) probe length and concentration, (4) washing temperature. We also provide advice on weakening background and improving the efficiency of RNA transcription in vitro. The expression of the BrrCLV3 gene in turnip was detected by the optimized system, and the applicability of the system was confirmed by using BrrWUSa. Conclusions: In this study, we established and optimized the mRNA ISH system for turnip. We explored and found that (1) FAA fixative was the optimized fixation method, (2) 30 min was the optimized protease K pretreatment time, (3) 100 bp, 100 ng/ml probe had good hybridization signal, (4) the optimized washing temperature was 52 °C. It provides a powerful method to locate mRNA in the tissue, which can study the expression and function of turnip's genes. As such, it has considerable advantages in terms of time and cost.

13.
Cell Death Dis ; 10(10): 784, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31611551

RESUMO

Molecular targeted agents, such as sorafenib, remain the only choice of an antitumor drug for the treatment of advanced hepatocellular carcinoma (HCC). The Notch signaling pathway plays central roles in regulating the cellular injury/stress response, anti-apoptosis, or epithelial-mesenchymal transition process in HCC cells, and is a promising target for enhancing the sensitivity of HCC cells to antitumor agents. The ADAM metalloprotease domain-17 (ADAM-17) mediates the cleavage and activation of Notch protein. In the present study, microRNA-3163 (miR-3163), which binds to the 3'-untranslated region of ADAM-17, was screened using online methods. miRDB and pre-miR-3163 sequences were prepared into lentivirus particles to infect HCC cells. miR-3163 targeted ADAM-17 and inhibited the activation of the Notch signaling pathway. Infection of HCC cells with miR-3163 enhanced their sensitivity to molecular targeted agents, such as sorafenib. Therefore, miR-3163 may contribute to the development of more effective strategies for the treatment of advanced HCC.

14.
J Agric Food Chem ; 67(40): 11077-11088, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31525039

RESUMO

Cuticular wax accumulation in plants contributes to drought tolerance. Here, we compared the drought levels on two varieties with different genotypes in turnip (Brassica rapa var. rapa) and found that the drought tolerance was higher in the waxy KTRG-B48a than in the wax-free KTRG-B48b. A combination of PacBio and Illumina sequencing analyses revealed that differential transcripts were mainly enriched in the wax synthesis pathway, and a splice variant (BrrWSD1-X2) was identified in the waxy KTRG-B48a. BrrWSD1-X2 had a stronger ability to synthesize wax esters than BrrWSD1-X1 using heterologous expression in yeast (Saccharomyces cerevisiae) mutant H1246a. Then, we speculated that the T to C transversion of the third intron and the higher number of TA repeats in the third intron of BrrWSD1 DNA in the waxy KTRG-B48a may result in a lower efficiency of splicing recognition of the third intron, resulting in the emergence of BrrWSD1-X2 in waxy varieties.


Assuntos
Brassica rapa/fisiologia , Ésteres/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ceras/metabolismo , Brassica rapa/genética , Secas , Processamento de RNA , Água/análise , Água/metabolismo
15.
World J Gastroenterol ; 25(32): 4764-4778, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31528100

RESUMO

BACKGROUND: Non-invasive evaluation for liver fibrosis is clinically important, especially in patients with undetectable hepatitis B virus (HBV) DNA treated with nucleoside analogs. AIM: To clarify the monitoring power of hepatitis B core-related antigen (HBcrAg) for hepatic histologic changes in patients with chronic hepatitis B (CHB) treated with entecavir. METHODS: This prospective multicenter study used multiple ordinal and multivariate logistics regression analysis to assess variables associated with Ishak fibrosis score and regression for fibrosis regression, respectively, in 403 CHB patients, including 374 with entecavir for 72 weeks (291 underwent paired liver biopsy) and 29 as controls. RESULTS: Level of HBcrAg correlated negatively with liver fibrosis staging (γ = -0.357, P < 0.001) in hepatitis B e antigen (HBeAg)-positive patients, and positively with liver fibrosis staging in HBeAg-negative patients. Higher HBcrAg concentration was associated with younger age, HBeAg positive status, high HBV DNA loads, high level of hepatitis B surface antigen (HBsAg) and higher necroinflammation, but not with HBV genotype. Serum concentration of HBcrAg, basal core promoter/precore (BCP/PC) mutant, quantitation of HBsAg (qHBsAg) and platelet counts were independently associated with Ishak fibrosis score on multiple ordinal regression. HBV DNA was undetectable in 88.37% of patients treated with entecavir at week 72, while their level of HBcrAg was still detectable. A greater reduction in post-treatment HBcrAg concentration was associated with the regression of hepatic fibrosis and histological improvement. HBcrAg concentration > 6.33 log IU/mL at baseline and logarithmic reduction > 1.03 log IU/mL at week 72 were associated with a higher chance of regression of liver fibrosis and histological improvement, respectively. CONCLUSION: HBcrAg level is associated with liver fibrosis progression. HBcrAg is an excellent monitor of hepatic histological changes, especially in CHB patients treated with nucleoside analogs.


Assuntos
Antivirais/uso terapêutico , Antígenos do Núcleo do Vírus da Hepatite B/sangue , Vírus da Hepatite B/isolamento & purificação , Hepatite B Crônica/tratamento farmacológico , Cirrose Hepática/diagnóstico , Adulto , Biomarcadores/sangue , DNA Viral/sangue , DNA Viral/isolamento & purificação , Progressão da Doença , Feminino , Guanina/análogos & derivados , Guanina/uso terapêutico , Antígenos do Núcleo do Vírus da Hepatite B/imunologia , Antígenos do Núcleo do Vírus da Hepatite B/isolamento & purificação , Vírus da Hepatite B/imunologia , Hepatite B Crônica/sangue , Hepatite B Crônica/patologia , Humanos , Fígado/patologia , Fígado/virologia , Cirrose Hepática/sangue , Cirrose Hepática/patologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento
16.
Plant Divers ; 41(4): 275-283, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31528787

RESUMO

The heavy metal ATPase (HMA) subfamily is mainly involved in heavy metal (HM) tolerance and transport in plants, but an understanding of the definite roles and mechanisms of most HMA members are still limited. In the present study, we identified 14 candidate HMA genes named BrrHMA1-BrrHMA8 from the turnip genome and analyzed the phylogeny, gene structure, chromosome distribution, and conserved domains and motifs of HMAs in turnip (Brassica rapa var. rapa). According to our phylogenetic tree, the BrrHMAs are divided into a Zn/Cd/Co/Pb subclass and Cu/Ag subclass. The BrrHMA members show similar structural characteristics within subclasses. To explore the roles of BrrHMAs in turnip, we compared the gene sequences and expression patterns of the BrrHMA genes between a Cd-tolerant landrace and a Cd-sensitive landrace. Most BrrHMA genes showed similar spatial expression patterns in both Cd-tolerant and Cd-sensitive turnip landraces; some BrrHMA genes, however, were differentially expressed in specific tissue in Cd-tolerant and Cd-sensitive turnip. Specifically, BrrHMA genes in the Zn/Cd/Co/Pb subclass shared the same coding sequence but were differentially expressed in Cd-tolerant and Cd-sensitive turnip landraces under Cd stress. Our findings suggest that the stable expression and up-regulated expression of BrrHMA Zn/Cd/Co/Pb subclass genes under Cd stress may contribute to the higher Cd tolerance of turnip landraces.

17.
New Phytol ; 224(4): 1512-1517, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31418867

RESUMO

A widely observed pollinator decline around the world has led to the prediction that terrestrial ecosystems could be disrupted as plant pollination suffers, but declining pollination success has not been tested rigorously in wild plants, and it still remains unclear how pollination success of plant species responds differently in the context of pollinator decline. By viewing the number of seeds per pod as a quantitative measure of successful pollination, we examined seed pods in 4637 herbarium specimens of 109 obligately outcrossing legumes collected over the past century. We found that only 13 species showed significant temporal change with nine of those as an increase. None of the three subfamilies of legumes showed a consistent trend, and the subfamily Papilionoideae with the most specialized flowers, had increasing seed number per pod more often than decreasing. We conclude that legume pollination in China shows no sign of disruption and the effects of plant-pollinator disruption may be more complicated than simplistic predictions have allowed.

18.
Bioresour Technol ; 292: 121994, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31437799

RESUMO

Bio-char samples were prepared from gasification of corn straw under N2, CO2 and H2O conditions, and systematically characterized to reveal the effects of gaseous agents on the evolution of char structural features during the gasification process. The results showed that the increase of reacting temperature had positive effects on the gasification of char in both H2O and CO2 atmospheres. The evolution of char pore structures under H2O and CO2 was quite different. The formation of micropores was facilitated by CO2, while mesopores and macropores were developed more in H2O condition. Besides, char structures obtained at 800 °C were more ordered than those obtained at 600 °C. Compared with the longitudinal merging, the aromatic layers preferred to grow laterally. Moreover, the mechanisms of gasification between char and gaseous agents were different. CO2 preferred to react with amorphous carbon, while the cross-linked carbon was more likely to be consumed during char gasification with H2O.


Assuntos
Carvão Vegetal , Gases , Biomassa , Dióxido de Carbono , Cinética
20.
J Exp Bot ; 70(19): 5101-5114, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31340000

RESUMO

FRIGIDA (FRI), as the major regulator of flowering time in Arabidopsis accessions, can activate its target FLOWERING LOCUS C (FLC) to delay flowering before vernalization. In addition to FLC, other FRI targets also exist in Arabidopsis. Although leaves sense environmental cues to modulate flowering time, it is not known if roots also regulate the floral transition. In this study, we investigated the spatio-temporal effect of FRI on flowering time. Local expression of FRI in the phloem and leaves activated FLC to delay flowering. Furthermore, we found that local expression of FRI in the roots also delayed flowering by activating other targets, MADS AFFECTING FLOWERING4 (MAF4) and MAF5, in the roots. Graft and genetic experiments revealed that the spatial expression of FRI in the root might generate a mobile signal, which is transmitted from roots to shoot and antagonizes the FT signal to delay flowering. Specifically expressing FRI in the embryo efficiently delayed flowering, even expressing FRI as early as the pro-embryo stage is enough to up-regulate FLC expression to delay flowering. Together, our findings demonstrate the spatio-temporal effect of FRI on delaying flowering, and we propose that root tissue also perceives the flowering signal to fine-tune the flowering time through MAF4/5 as novel targets of FRI.

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