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1.
Org Biomol Chem ; 22(25): 5014-5031, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38831700

RESUMO

Transition metal catalyzed C-H bond activation has become one of the most important tools for constructing new chemical bonds. Introducing directing groups to the substrates is the key to a successful reaction, these directing groups can also be further transformed in the reaction. Amidines with their unique structure and reactivity are ideal substrates for transition metal-catalyzed C-H transformations. This review describes the major advances and mechanistic investigations of the C-H activation/annulation tandem reactions of amidines until early 2024, focusing on metal-catalyzed C-H activation of amidines with unsaturated compounds, such as alkynes, ketone, vinylene carbonate, cyclopropanols and their derivatives. Meanwhile this manuscript also explores the reaction of amidines with different carbene precursors, for example diazo compounds, azide, triazoles, pyriodotriazoles, and sulfoxonium ylides as well as their own C-H bond activation/cyclization reactions. A bright outlook is provided at the end of the manuscript.

2.
Plant Dis ; 2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38679598

RESUMO

Aucuba japonica var. variegata Dombrain is a common evergreen cultivated ornamental in China (Li et al. 2016). In December 2022, severe leaf blight on A. japonica was observed next to the Meishiyuan of Zhejiang Normal University (29°8'4″N, 119°37'54″E) in Jinhua City, Zhejiang Province, China. There were seven plants in the surveyed area, and over 50% of leaves were affected. The early symptoms were small gray spot parts with brown borders on the tip of the leaves. Then the grey parts gradually expanded and became brownish black. In severe cases, the whole leaves became black and blighted. To identify the pathogen, 5 symptomatic leaves were randomly collected from 5 plants and cut into small pieces (5 mm × 5 mm), surface disinfected in 1% sodium hypochlorite solution for 3 min, followed by 75% alcohol for 30 s, then rinsed in sterile distilled water thrice. Tissues were cultured on potato dextrose agar (PDA) and incubated at 28°C for 7 days. Pure cultures were obtained by the single-spore method. Thirteen strains were isolates from the tissues, and nine of them showed similar morphological characteristics. Colonies were white initially, then became gray. The undersides of the colonies became black gradually. Hyaline, fusiform conidia (n = 30) were 17.1 to 24.76 µm (average 20.39 ± 1.906 µm) in length and 5.4 to 6.61 µm (average 6.19 ± 0.434 µm) in width. The DNA of nine isolates were extracted by Ezup Column Bacteria Genomic DNA Purification Kit, and their sequences were identical, so they were named QM1. The internal transcribed spacer (ITS) region, translation elongation factor 1-α (TEF1), and ß-tubulin (TUB2) genes were amplified with primer pairs ITS1/ITS4, TEF1-728F/TEF1-986R and ßt2a/ßt2b (Slippers et al. 2004), respectively. The BLAST analysis indicated that ITS (OR215464), TEF1 (OR243689), and TUB2 (OR243688) of the isolate QM1 were 99 to 100% identical to those of Botryosphaeria dothidea (GenBank accession nos. MH329646 for ITS sequences; OL891702 for TEF1 sequences; MK511445 for TUB2 sequences). In addition, the phylogenetic tree based on sequences from ITS, TEF1 and TUB2 was constructed with MEGA 11 by use of the maximum likelihood method with 1,000 bootstrapping iterations. Based on the multi-locus phylogeny and morphological features, the isolate QM1 was identified as B. dothidea. To test the Koch's postulates, ten leaves from three healthy two- to three-year-old A. japonica plants were surface disinfested with 75% ethanol for 30 s, rinsed with ddH2O three times. The leaves were wounded with a sterile needle and inoculated with 2ml drop of the isolate QM1 conidial suspension (106 spores/mL), with sterile distilled water as a control. All plants were placed in a greenhouse at 28°C, >70% relative humidity and 12 h light/day. The experiment was repeated three times. After 7 days, leaves of the inoculated group showed symptoms similar to those observed on the naturally infected leaves, while leaves of the control group remained asymptomatic. The pathogen was reisolated from inoculated leaves and was confirmed as B. dothidea based on morphological and molecular analyses. It has been reported B. dothidea cause leaf disease in a wide range of hosts in China, such as Camellia oleifera (Hao et al. 2023), Kadsura coccinea (Su et al. 2021). To our knowledge, this is the first report of Botryosphaeria dothidea causing leaf blight on Aucuba japonica in Zhejiang Province of China. B. dothidea are usually secondary invaders and are known to cause diseases in stressed plants. The results further expand the host-range of B. dothidea, and would help to establish control strategy against the disease.

3.
Plant Dis ; 2023 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-37642547

RESUMO

Lactuca indica, an annual or biennial herbaceous plant, is widespread in valleys, shrubland, ditches, hillside meadows or fields (Wang et al. 2003). In China, it is widely used as medicine and high protein feed for herbivorous animal husbandry. In July 2022, leaf blight on L. indica was observed at Zhejiang Normal University (29°8'4″N, 119°37'54″E) in Jinhua City, Zhejiang Province, China. 70% of the 87 plants investigated were infected. Small brown spots with a yellow halos first appeared on the leaves, then became irregular necrotic spots until the entire leaf wilted and fell off. To identify the pathogen, four symptomatic leaves were collected and disinfected according to Wang et al. 2023. Then they were transferred onto potato dextrose agar (PDA), and incubated at 28°C for 7 days. To obtain the pure culture, the marginal mycelium was transferred to a new PDA plate. The colony of the isolated LPB-1 was light gray and regularly round at the early stage, and then changed to dark gray and villous. The back of the culture plate appeared sooty black. The conidia of the isolated fungi (n=50) were in chains, brown, obclavate, ovoid or ellipsoid, with an average size of 29.09 µm long and 6.41 µm wide, with 0 to 3 longitudinal and 1 to 7 transverse septa. These cultural and morphological characteristics were consistent with those of Alternaria alternata (Simmons 2007). To identify the strain, internal transcribed spacer (ITS) region, RNA polymerase Ⅱ second largest subunit (RPB2), and translation elongation factor 1-alpha (TEF1-α) genes were amplified with the primers ITS1/ITS4 (White et al. 1990), RPB2-5F/RPB2-7cR (Liu et al. 1999) and EF1-728F/EF1-986R (Carbone & Kohn 1999). The RPB2 (OP909715), TEF-1α (OP909714), and ITS (OP776880) were 99 to 100% identical to those of A. alternata (GenBank accession nos. MZ170963.1, MK605900.1, and MK605895.1 for RPB2 sequences; ON951981.1, KJ008702.1, and MK672900.1 for TEF-1α sequences; OP850817.1, OP811328.1, and OP740510.1 for ITS sequences). In addition, the phylogenetic analysis also showed that the stain LPB-1 was A. alternata. To complete Koch's postulates, the conidial suspension (1×108 conidia/mL) were spray-inoculated on healthy leaves of three mature L. indica plants with sterile water as a control. All plants were incubated at 28 ℃ in a greenhouse with 12-h-light/12-h-dark photoperiod and approximately 70% humidity (Li et al. 2019). Fourteen days after incubation, the inoculated leaves showed symptoms similar to those of naturally infected leaves, while the controls remained asymptomatic. The pathogen reisolated from the inoculated leaves had the same morphological characteristics and molecular identification results as the original isolate. All the results shown above indicated that A. alternata was responsible for the leaf blight of L. indica. As far as we know, this is the first report of leaf blight caused by Alternaria alternata on Lactuca indica in China. The identification of the pathogen could provide relevant information for the establishment of methods to control the disease.

4.
Molecules ; 28(15)2023 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-37570722

RESUMO

Exploring anode materials with an excellent electrochemical performance is of great significance for supercapacitor applications. In this work, a N-doped-carbon-nanofiber (NCNF)-supported Fe3C/Fe2O3 nanoparticle (NCFCO) composite was synthesized via the facile carbonizing and subsequent annealing of electrospinning nanofibers containing an Fe source. In the hybrid structure, the porous carbon nanofibers used as a substrate could provide fast electron and ion transport for the Faradic reactions of Fe3C/Fe2O3 during charge-discharge cycling. The as-obtained NCFCO yields a high specific capacitance of 590.1 F g-1 at 2 A g-1, superior to that of NCNF-supported Fe3C nanoparticles (NCFC, 261.7 F g-1), and NCNFs/Fe2O3 (NCFO, 398.3 F g-1). The asymmetric supercapacitor, which was assembled using the NCFCO anode and activated carbon cathode, delivered a large energy density of 14.2 Wh kg-1 at 800 W kg-1. Additionally, it demonstrated an impressive capacitance retention of 96.7%, even after 10,000 cycles. The superior electrochemical performance can be ascribed to the synergistic contributions of NCNF and Fe3C/Fe2O3.

5.
Diabetes Metab Res Rev ; 38(1): e3477, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34041844

RESUMO

AIMS: Glycated albumin (GA) is a biomarker for short-term (2-3 weeks) glycaemic control. However, the predictive utility of GA for diabetes and prediabetes is largely uncharacterised. We aimed to investigate the relationships of baseline serum GA levels with incident diabetes and prediabetes. METHODS: This was a longitudinal cohort study involving 516 subjects without diabetes or prediabetes at baseline. Blood glucose levels were observed during follow-up. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated using COX proportional hazard models. Receiver operating characteristic curves and areas under the curves (AUCs) were used to evaluate the discriminating abilities of glycaemic biomarkers and prediction models. RESULTS: During a 9-year follow-up, 51 individuals (9.88%) developed diabetes and 92 (17.83%) prediabetes. Unadjusted HRs (95% CI) for both diabetes and prediabetes increased proportionally with increasing GA levels in a dose-response manner. Multivariable-adjusted HRs (95% CI) for diabetes were significantly elevated from 1.0 (reference) to 5.58 (1.86-16.74). However, the trend was no longer significant for prediabetes after multivariable adjustment. AUCs for GA, fasting blood glucose (FBG) and 2-h postprandial blood glucose (2h-PBG) for predicting diabetes were 0.698, 0.655 and 0.725, respectively. The AUCs for GA had no significant differences compared with those for FBG (p = 0.376) and 2h-PBG (p = 0.552). Replacing FBG or 2h-PBG or both with GA in diabetes prediction models made no significant changes to the AUCs of the models. CONCLUSIONS: GA is of good prognostic utility in predicting diabetes. However, GA may not be a useful biomarker for predicting prediabetes.


Assuntos
Diabetes Mellitus Tipo 2 , Estado Pré-Diabético , Biomarcadores , Glicemia , Estudos de Coortes , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Hemoglobinas Glicadas/análise , Produtos Finais de Glicação Avançada , Humanos , Estudos Longitudinais , Estado Pré-Diabético/diagnóstico , Estado Pré-Diabético/epidemiologia , Estudos Retrospectivos , Albumina Sérica , Albumina Sérica Glicada
6.
Endocr Pract ; 28(2): 135-141, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34481972

RESUMO

OBJECTIVE: The present study aimed to evaluate gestational diabetes mellitus (GDM) incidence in pregnant women following the Mediterranean diet (MedDiet) with the addition of extra virgin olive oil (EVOO) and pistachios. METHODS: A total of 560 pregnant patients were enrolled in the present study. The MedDiet was introduced in both the interventional group (IG) and the control group. The women in the IG received 40 mL of EVOO every day along with 25 to 30 g of roasted pistachios. The incidence of GDM was recorded along with specific maternal and neonatal outcomes. RESULTS: The nutritional scores and MedDiet adherence screener scores were not statistically different between the groups at baseline, but the difference was statistically significant and higher in the IG at 24 to 28 weeks (P = .001) and at 36 to 38 weeks (P = .001). GDM was diagnosed in 51 (20.4%) women in the control group and 34 (13.6%) women in the IG. The MedDiet significantly reduced GDM incidence (P = .02) after adjusting for confounding factors. CONCLUSION: The present study shows that dietary intervention in pregnant women, including a MedDiet and increased consumption of EVOO and pistachios, decreases the incidence of GDM.


Assuntos
Diabetes Gestacional , Dieta Mediterrânea , Pistacia , Diabetes Gestacional/epidemiologia , Diabetes Gestacional/prevenção & controle , Feminino , Humanos , Incidência , Recém-Nascido , Azeite de Oliva , Gravidez
7.
Plant Dis ; 2022 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-36194731

RESUMO

Oxalis articulata is now widely cultivated in China as an ornamental species, and thus found in abundance in agricultural farms, gardens, and lawns. In December 2021, some severely infected Oxalis articulata were observed at many places at Zhejiang Normal University (29°8'4″N, 119°37'54″E) in Jinhua City, Zhejiang Province, China. Yellow was first observed on the margin of the leaves, leading to light brown and wilting at a later stage. To identify the pathogen, symptomatic leaves were collected and cut into small pieces, surface disinfected in 1% sodium hypochlorite solution for 3 min, followed by 75% alcohol for 0.5 min, then rinsed in sterile distilled water thrice. Then they were transferred onto Luria-Bertani medium and incubated at 28°C for 3 days. The colonies were round, yellow, viscous and smooth, which was consistent with the characteristics of Pantoea agglomerans (Li et al. 2020; Zhang et al. 2022). The bacteria tested gram-negative, negative for indole test and Voges-Proskauer reaction, and positive for methyl red reaction, lysine decarboxylase and ornithine decarboxylase. In addition, the bacteria can utilize D-xylose, sorbitol, adonitol, and glucose, but can't utilize raffinose, urea, and Simmons. Meanwhile the bacteria can not produce H2S, and can not produce gas from D-glucose as well. These results of physiological and biochemical characteristics were consistent with those of Pantoea agglomerans (Gavini et al. 1989). To identify the strain, the 16S rDNA gene fragment was amplified by polymerase chain reaction (PCR) using universal primers 8F and 1510R, and sequenced. The BLAST results indicated that the 16S rDNA sequence of the strain OAPB-1, deposited under GenBank accession LC709256, showed 99.93% (1376/1377) and 99.49% (1370/1377) identity to the corresponding sequence of Pantoea agglomerans FC2948 (MH532498.1) and the type strain Pantoea agglomerans DSM 3493 (AJ233423) respectively. The Neighbor-Joining phylogenetic tree generated using MEGA11 indicated that it formed a clade with the other P. agglomerans. Furthermore, the phylogenetic analysis based on sequences of housekeeping genes (atpD, rpoB and infB; GenBank accession LC722492 to LC722494) showed the same result. Based on the above results, the strain OAPB-1 from Zhejiang was identified as P.agglomerans. To test the Koch's postulates, bacterial suspensions (2×108CFU/mL) were injected into the middle of healthy leaves of mature plants with sterile water as a control. Then the plants were placed at 28°C in a light incubator with 12-h-light/12-h-dark photoperiod and approximately 60% humidity. Leaves in the inoculated group showed symptoms similar to those observed on the naturally infected leaves, while leaves in the control group showed no symptoms. The pathogen was reisolated from inoculated leaves, and its morphological characteristics and molecular identification results were consistent with those of the original isolate. P. agglomerans is a bacterium associated with plants, and also infects humans and animals (Dutkiewicz et al. 2016). In China, it has been reported to infect many kinds of plants (Fan et al. 2022; Guo et al. 2020; Han et al. 2020; Li et al. 2020; She et al. 2019; Zhang et al. 2022). As far as we know, this is the first report of P. agglomerans causing bacterial wilt on Oxalis articulata in China. These results further expand the range of plants that can be infected by P. agglomerans, and help to establish an effective control strategy against the disease.

8.
Wei Sheng Wu Xue Bao ; 52(1): 77-82, 2012 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-22489463

RESUMO

OBJECTIVE: The purpose of the present study was to produce the Rpf (resuscitation promoting factor) protein by cloning and expressing the rpf gene, secreted by Micrococcus luteus IAM 14879, in Escherichia coli and to evaluate its role in the recovery of the VBNC (viable but non-culturable) state in high-GC Gram-positive bacteria. METHODS: Genomic DNA was extracted from Micrococcus luteus IAM 14879 and the rpf gene was amplified by PCR using specific primers. The PCR products was purified, cloned into a pET15b expression vector, and transformed into Escherichia coli BL21 (DE3). Then the pET15b plasmid expression vector was used to confirm the purification of the recombinant proteins via SDS-PAGE. The VBNC state cells from the high-GC Gram-positive bacteria, Rhodococcus sp. DS471, were used to confirm the promotion and recovery of growth capacity. Rhodococcus sp. DS471 were isolated from soil and closely related to Micrococcus luteus IAM 14879. RESULTS: The gene sequences confirmed that the rpf gene from Micrococcus luteus IAM 14879 that was expressed in Escherichia coli, was 672 bp. SDS-PAGE analysis showed that the recombinant Rpf protein was obtained successfully, and further studies showed it capable of promoting the recovery of the VBNC state by about 100-fold relative to the control. CONCLUSION: Rpf of Micrococus luteus IAM 14879 can be successfully cloned and expressed in Escherichia coli and shows a strong ability to promote the recovery of the VBNC state of cells of Rhodococcus sp. DS471.


Assuntos
Proteínas de Bactérias/fisiologia , Citocinas/fisiologia , Micrococcus luteus/genética , Rhodococcus/fisiologia , Proteínas de Bactérias/genética , Clonagem Molecular , Citocinas/genética
9.
Plant Methods ; 18(1): 89, 2022 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-35765077

RESUMO

BACKGROUND: Salicylic acid (SA) is one of the plant hormones, which plays crucial roles in signaling transduction in plant growth, disease resistance, and leaf senescence. Arabidopsis (Arabidopsis thaliana) SA 3-hydroxylase (S3H) and 5-hydroxylase (S5H) are key enzymes which maintain SA homeostasis by catalyzing SA to 2,3-dihydroxybenzoic acid (DHBA) and 2,5-DHBA, respectively. RESULTS: SA deficient transgenic Arabidopsis lines were generated by introducing two binary vectors S5Hpro::EGFP-S3H and 35Spro::EGFP-S3H respectively, in which the expression of S3H is under the control of the S5H promoter or CaMV 35S promoter. Compared with the constitutive expression of S3H gene under the control of 35S promoter, the S3H gene under the native S5H promoter is activated by endogenous SA and results in a dynamic control of SA catabolism in a feedback mode. The SA accumulation, growth, leaf senescence, and pathogen resistance of the S5Hpro::GFP-S3H transgenic plants were investigated in parallel with NahG transgenic plants. The SA levels in the S5Hpro::EGFP-S3H transgenic plants were similar to or slightly lower than those of NahG transgenic Arabidopsis and resulted in SA deficient phenotypes. The low-SA trait of the S5Hpro::EGFP-S3H transgenic lines was inherited stably in the later generations. CONCLUSIONS: Compared with NahG transgenic lines producing by-product catechol, S5Hpro::EGFP-S3H transgenic lines reduce SA levels by converting SA to a native product 2,3-DHBA for catabolism. Together, we provide new SA-deficient germplasms for the investigations of SA signaling in plant development, leaf senescence, and disease resistance.

10.
J Fluoresc ; 21(2): 813-23, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21128102

RESUMO

Two new La(III) and Sm(III) complexes with enrofloxacin (HER, 1-cyclopropyl-7-(4-ethyl-1-piperazinyl)-6-fluoro-1,4-dihydro-4-oxo-3-quinoline carboxylic acid, C(19)H(21)FN(3)O(3)), [La(2)(ER)(6)(H(2)O)(2)]·14H(2)O(1) and [Sm(2)(ER)(6)(H(2)O)(2)]·14H(2)O(2) have been synthesized and characterized by elemental analysis, FT-IR, TG-DTG and X-ray single crystal diffraction. Both of the complexes are triclinic system with space group Pi. The structure of the complexes show that each rare earth atom in both complexes was nine-coordinated. Two of the enrofloxacin ions acted as tridentate chelate and bridging ligands, while the others as bidentate chelate ligands. The binding reaction between the complexes and bovine serum albumin (BSA) was studied by UV-vis absorption spectra and fluorescence spectroscopy. The results indicated that the two complexes had a quite strong ability to quench the fluorescence from BSA and the binding reaction was mainly a static quenching process. The binding constants K ( A )/(L·mol(-1)) were 1.46 × 10(5)(1) and 8.59 × 10(6)(2) and one binding site was formed. The synchronous spectroscopy suggested that tryptophan residues were placed in BSA. It was also found that the two complexes exhibited greater antimicrobial activity than enrofloxacin at given concentrations.


Assuntos
Fluoroquinolonas/química , Lantânio/química , Compostos Organometálicos/química , Compostos Organometálicos/farmacologia , Samário/química , Soroalbumina Bovina/metabolismo , Animais , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Sítios de Ligação , Bovinos , Cristalografia por Raios X , Enrofloxacina , Modelos Moleculares , Compostos Organometálicos/síntese química , Compostos Organometálicos/metabolismo , Conformação Proteica/efeitos dos fármacos , Soroalbumina Bovina/química , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
11.
ACS Omega ; 4(25): 21000-21004, 2019 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-31867491

RESUMO

Biodegradation of ferulic acid, by an endophytic fungus Colletotrichum gloeosporioides TMTM-13 associated with Ostrya rehderiana Chun, was explored in this study. Ferulic acid was completely degraded by TMTM-13 as its initial concentration was lower than 400 mg L-1. Generally, the initial concentration of ferulic acid and fungal biomass of TMTM-13 kept synchronously growing up as the concentration was lower than 400 mg L-1. Fungal biomass reached a maximum of almost 1.177 g L-1 under concentrations of 400-450 mg L-1. HPLC-MS analysis indicated that ferulic acid ultimately degraded to vanillin, vanillic acid, acetovanillone, and dihydroconiferyl alcohol by TMTM-13. This study was the first report about an endophytic fungus associated with O. rehderiana Chun that has great potential for practical application in ferulic acid contaminated environments.

12.
Rice (N Y) ; 8: 18, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26029330

RESUMO

BACKGROUND: Rice mutant, spl5 (spotted leaf 5), has spontaneous hypersensitive-like lesions on its leaves and shows enhanced resistance to pathogens, indicating that SPL5 plays a role in programmed cell death (PCD) and disease resistance. To understand the molecular mechanism of SPL5 gene, we investigated the transcriptome profiles of the spl5 mutant leaves with few lesions (FL) and leaves with many lesions (ML) compared to the wild-type (WT) leaves respectively by microarray. RESULTS: The data from microarray revealed that 243 and 896 candidate genes (Fold change ≥ 3.0) were up- or down-regulated in the spl5-FL and spl5-ML, respectively, and a large number of these genes involved in biotic defense responses or reactive oxygen species (ROS) metabolism. Interestingly, according to our microarray and real-time PCR assays, the expressions of a transcription factor OsWRKY14 and genes responsible for the biosynthesis of serotonin, anthranilate synthase (AS), indole-3-glycerolphosphate synthase (IGPS), tryptophan synthase (TS) and tryptophan decarboxylase (TDC) were significantly up-regulated in the spl5 mutant. It has been reported previously that TS and TDC expressions are regulated by OsWRKY14 in rice, which raises the possibility that OsWRKY14 regulates serotonin production through the up-regulation of TS and TDC. Our HPLC analysis further confirmed that serotonin levels were higher in the leaves of spl5 mutant than that in WT. CONCLUSIONS: Since the serotonin plays a critical role in inducing disease-resistance, the increased serotonin level may contribute, at least partly, to the disease resistance in spl5. The SPL5 gene may act as a negative regulatory factor activating the serotonin metabolic pathway, and these results might provide a new insight into the spl5-induced defense response mechanisms in plants.

13.
Rice (N Y) ; 6(1): 1, 2013 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-24280096

RESUMO

BACKGROUND: A lesion-mimic mutant in rice (Oryza sativa L.), spotted leaf 5 (spl5), displays a disease-resistance-enhanced phenotype, indicating that SPL5 negatively regulates cell death and resistance responses. To understand the molecular mechanisms of SPL5 mutation-induced cell death and resistance responses, a proteomics-based approach was used to identify differentially accumulated proteins between the spl5 mutant and wild type (WT). RESULTS: Proteomic data from two-dimensional gel electrophoresis showed that 14 candidate proteins were significantly up- or down-regulated in the spl5 mutant compared with WT. These proteins are involved in diverse biological processes including pre-mRNA splicing, amino acid metabolism, photosynthesis, glycolysis, reactive oxygen species (ROS) metabolism, and defense responses. Two candidate proteins with a significant up-regulation in spl5 - APX7, a key ROS metabolism enzyme and Chia2a, a pathogenesis-related protein - were further analyzed by qPCR and enzyme activity assays. Consistent with the proteomic results, both transcript levels and enzyme activities of APX7 and Chia2a were significantly induced during the course of lesion formation in spl5 leaves. CONCLUSIONS: Many functional proteins involving various metabolisms were likely to be responsible for the lesion formation of spl5 mutant. Generally, in spl5, the up-regulated proteins involve in defense response or PCD, and the down-regulated ones involve in amino acid metabolism and photosynthesis. These results may help to gain new insight into the molecular mechanism underlying spl5-induced cell death and disease resistance in plants.

14.
J Agric Food Chem ; 61(7): 1521-4, 2013 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-23360202

RESUMO

Two main antifungal metabolites resistomycin and tetracenomycin D were isolated and purified from a termite-associated Streptomyces canus BYB02 by column chromatography. The structures of isolated compounds were determined on the basis of extensive spectroscopic analysis. Resistomycin possessed strong activities against mycelial growth of Valsa mali (IC(50) = 1.1 µg/mL) and Magnaporthe grisea (IC(50) = 3.8 µg/mL), which were comparable to those of referenced cycloheximide, with IC(50) values of 2.3 and 0.3 µg/mL, respectively. A further spore germination test showed that resistomycin exhibited potent reduction in spore germination for M. grisea , with an IC(50) value of 5.55 µg/mL. Finally, the in vivo antifungal activity experiment showed that resistomycin possessed significant preventive efficacy against rice blast, which was more potent than that of referenced carbendazim, with control efficacies of 66.8 and 58.7%, respectively. The present results suggest that resistomycin has potential to be used as a fungicide.


Assuntos
Fungicidas Industriais/farmacologia , Isópteros/microbiologia , Streptomyces/metabolismo , Animais , Ascomicetos/efeitos dos fármacos , Ascomicetos/crescimento & desenvolvimento , Benzopirenos/isolamento & purificação , Benzopirenos/farmacologia , Cicloeximida/isolamento & purificação , Cicloeximida/farmacologia , Fermentação , Fungicidas Industriais/isolamento & purificação , Concentração Inibidora 50 , Magnaporthe/efeitos dos fármacos , Magnaporthe/crescimento & desenvolvimento , Oryza , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Esporos Fúngicos/efeitos dos fármacos , Esporos Fúngicos/crescimento & desenvolvimento
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