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1.
Beilstein J Org Chem ; 20: 346-378, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38410775

RESUMO

Due to their ease of preparation, stability, and diverse reactivity, N-hydroxyphthalimide (NHPI) esters have found many applications as radical precursors. Mechanistically, NHPI esters undergo a reductive decarboxylative fragmentation to provide a substrate radical capable of engaging in diverse transformations. Their reduction via single-electron transfer (SET) can occur under thermal, photochemical, or electrochemical conditions and can be influenced by a number of factors, including the nature of the electron donor, the use of Brønsted and Lewis acids, and the possibility of forming charge-transfer complexes. Such versatility creates many opportunities to influence the reaction conditions, providing a number of parameters with which to control reactivity. In this perspective, we provide an overview of the different mechanisms for radical reactions involving NHPI esters, with an emphasis on recent applications in radical additions, cyclizations and decarboxylative cross-coupling reactions. Within these reaction classes, we discuss the utility of the NHPI esters, with an eye towards their continued development in complexity-generating transformations.

2.
Front Aging ; 4: 1296409, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38021400

RESUMO

Rothmund-Thomson syndrome (RTS) is a rare autosomal recessive disorder characterized by a range of clinical symptoms, including poikiloderma, juvenile cataracts, short stature, sparse hair, eyebrows/eyelashes, nail dysplasia, and skeletal abnormalities. While classically associated with mutations in the RECQL4 gene, which encodes a DNA helicase involved in DNA replication and repair, three additional genes have been recently identified in RTS: ANAPC1, encoding a subunit of the APC/C complex; DNA2, which encodes a nuclease/helicase involved in DNA repair; and CRIPT, encoding a poorly characterized protein implicated in excitatory synapse formation and splicing. Here, we review the clinical spectrum of RTS patients, analyze the genetic basis of the disease, and discuss molecular functions of the affected genes, drawing some novel genotype-phenotype correlations and proposing avenues for future studies into this enigmatic disorder.

3.
Angew Chem Int Ed Engl ; 62(6): e202215422, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36454656

RESUMO

Dearomatization reactions involving radical cyclizations can facilitate the synthesis of complex polycyclic systems that find applications in medicinal chemistry and natural product synthesis. Here we employ redox-neutral photocatalysis to affect a radical spirocyclization that transforms biaryls into spirocyclic cyclohexadienones under mild reaction conditions. In a departure from previously reported methods, our work demonstrates the polarity mismatched addition of a nucleophilic radical to an electron rich arene, and allows the regioselective synthesis of 2,4- or 2,5-cyclohexadienones with broad functional group tolerance. By transforming biaryls into spirocycles, our methodology accesses underexplored three-dimensional chemical space, and provides an efficient means of creating quaternary spirocenters that we apply to the first synthesis of the cytotoxic plant metabolite denobilone A.

4.
Planta ; 257(1): 6, 2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36437384

RESUMO

MAIN CONCLUSION: Recognition of the interaction of Trichoderma during the evolution of land plants plays a potential key role in the development of the salicylic acid defense pathway and the establishment of a mutualistic relationship. Marchantia polymorpha is a common liverwort considered in recent years as a model plant for evolutionary studies on plant-microorganism interactions. Despite the lack of research, remarkable results have been reported regarding the understanding of metabolic and evolutionary processes of beneficial and/or harmful interactions, owing to a better understanding of the origin and evolution of different plant defense pathways. In this study, we have carried out work on the direct and indirect interactions (exudates and volatiles) of M. polymorpha with different species of the fungal genus Trichoderma. These interactions showed different outcomes, including resistance or even growth promotion and disease. We have analyzed the level of tissue colonization and defense-related gene expression. Furthermore, we have used the pteridophyte Dryopteris affinis and the angiosperm Arabidopsis thaliana, as subsequent steps in plant evolution, together with the plant pathogen Rhizoctonia solani as a control of plant pathogenicity. Trichoderma virens, T. brevicompactum and T. hamatum are pathogens of M. polymorpha, while exudates of T. asperellum are harmful to the plant. The analysis of the expression of several defense genes in M. polymorpha and A. thaliana showed that there is a correlation of the transcriptional activation of SA-related genes with resistance or susceptibility of M. polymorpha to Trichoderma. Moreover, exogenous SA provides resistance to the virulent Trichoderma species. This beneficial fungus may have had an evolutionary period of interaction with plants in which it behaved as a plant pathogen until plants developed a defense system to limit its colonization through a defense response mediated by SA.


Assuntos
Arabidopsis , Marchantia , Trichoderma , Marchantia/genética , Marchantia/metabolismo , Arabidopsis/metabolismo , Ácido Salicílico/metabolismo , Trichoderma/genética , Simbiose
5.
Artigo em Inglês | MEDLINE | ID: mdl-35649682

RESUMO

Human DNA polymerases can bypass DNA lesions performing translesion synthesis (TLS), a mechanism of DNA damage tolerance. Tumor cells use this mechanism to survive lesions caused by specific chemotherapeutic agents, resulting in treatment relapse. Moreover, TLS polymerases are error-prone and, thus, can lead to mutagenesis, increasing the resistance potential of tumor cells. DNA polymerase eta (pol eta) - a key protein from this group - is responsible for protecting against sunlight-induced tumors. Xeroderma Pigmentosum Variant (XP-V) patients are deficient in pol eta activity, which leads to symptoms related to higher sensitivity and increased incidence of skin cancer. Temozolomide (TMZ) is a chemotherapeutic agent used in glioblastoma and melanoma treatment. TMZ damages cells' genomes, but little is known about the role of TLS in TMZ-induced DNA lesions. This work investigates the effects of TMZ treatment in human XP-V cells, which lack pol eta, and in its complemented counterpart (XP-V comp). Interestingly, TMZ reduces the viability of XP-V cells compared to TLS proficient control cells. Furthermore, XP-V cells treated with TMZ presented increased phosphorylation of H2AX, forming γH2AX, compared to control cells. However, cell cycle assays indicate that XP-V cells treated with TMZ replicate damaged DNA and pass-through S-phase, arresting in the G2/M-phase. DNA fiber assay also fails to show any specific effect of TMZ-induced DNA damage blocking DNA elongation in pol eta deficient cells. These results show that pol eta plays a role in protecting human cells from TMZ-induced DNA damage, but this can be different from its canonical TLS mechanism. The new role opens novel therapeutic possibilities of using pol eta as a target to improve the efficacy of TMZ-based therapies against cancer.


Assuntos
Antineoplásicos , Xeroderma Pigmentoso , Antineoplásicos/farmacologia , DNA , Dano ao DNA , DNA Polimerase Dirigida por DNA/genética , DNA Polimerase Dirigida por DNA/metabolismo , Humanos , Temozolomida/farmacologia , Xeroderma Pigmentoso/genética
6.
J Biol Chem ; 297(3): 101041, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34358560

RESUMO

SARS-CoV-2 nonstructural protein 3 (Nsp3) contains a macrodomain that is essential for coronavirus pathogenesis and is thus an attractive target for drug development. This macrodomain is thought to counteract the host interferon (IFN) response, an important antiviral signalling cascade, via the reversal of protein ADP-ribosylation, a posttranslational modification catalyzed by host poly(ADP-ribose) polymerases (PARPs). However, the main cellular targets of the coronavirus macrodomain that mediate this effect are currently unknown. Here, we use a robust immunofluorescence-based assay to show that activation of the IFN response induces ADP-ribosylation of host proteins and that ectopic expression of the SARS-CoV-2 Nsp3 macrodomain reverses this modification in human cells. We further demonstrate that this assay can be used to screen for on-target and cell-active macrodomain inhibitors. This IFN-induced ADP-ribosylation is dependent on PARP9 and its binding partner DTX3L, but surprisingly the expression of the Nsp3 macrodomain or the deletion of either PARP9 or DTX3L does not impair IFN signaling or the induction of IFN-responsive genes. Our results suggest that PARP9/DTX3L-dependent ADP-ribosylation is a downstream effector of the host IFN response and that the cellular function of the SARS-CoV-2 Nsp3 macrodomain is to hydrolyze this end product of IFN signaling, rather than to suppress the IFN response itself.


Assuntos
ADP-Ribosilação , COVID-19/virologia , Interferons/metabolismo , Proteínas de Neoplasias/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo , SARS-CoV-2/metabolismo , Transdução de Sinais , Ubiquitina-Proteína Ligases/metabolismo , Humanos
7.
Preprint em Inglês | bioRxiv | ID: ppbiorxiv-438552

RESUMO

SARS-CoV-2 non-structural protein 3 (Nsp3) contains a macrodomain that is essential for virus replication and is thus an attractive target for drug development. This macrodomain is thought to counteract the host interferon (IFN) response, an important antiviral signalling cascade, via the removal of ADP-ribose modifications catalysed by host poly(ADP-ribose) polymerases (PARPs). Here, we show that activation of the IFN response induces ADP-ribosylation of host proteins and that ectopic expression of the SARS-CoV-2 Nsp3 macrodomain reverses this modification in human cells. We further demonstrate that this can be used to screen for cell-active macrodomain inhibitors without the requirement for BSL-3 facilities. This IFN-induced ADP-ribosylation is dependent on the PARP9/DTX3L heterodimer, but surprisingly the expression of Nsp3 macrodomain or PARP9/DTX3L deletion do not impair STAT1 phosphorylation or the induction of IFN-responsive genes. Our results suggest that PARP9/DTX3L-dependent ADP-ribosylation is a downstream effector of the host IFN response and that the cellular function of the SARS-CoV-2 Nsp3 macrodomain is to hydrolyse this end product of IFN signalling, and not to suppress the IFN response itself.

8.
Actas Esp Psiquiatr ; 49(1): 12-23, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33533015

RESUMO

Vitamin D is a fat-soluble vitamin that performs multiple functions in the body. In addition to regulating calcium and phosphate levels in the body and contributing to bone mineralization, it participates in various brain and neurocognitive processes. In fact, the deficiency of this vitamin has also been linked to various psychiatric disorders, including depression.


Assuntos
Depressão/epidemiologia , Deficiência de Vitamina D/epidemiologia , Vitamina D/uso terapêutico , Depressão/tratamento farmacológico , Suplementos Nutricionais , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Deficiência de Vitamina D/tratamento farmacológico
9.
Front Plant Sci ; 11: 575861, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33193517

RESUMO

Wheat crop production needs nitrogen (N) for ensuring yield and quality. High doses of inorganic N fertilizer are applied to soil before sowing (basal dressing), with additional doses supplied along the cultivation (top dressing). Here, a long-term wheat field trial (12 plots), including four conditions (control, N top dressing, Trichoderma harzianum T34 seed-inoculation, and top dressing plus T34) in triplicate, was performed to assess, under high basal N fertilization, the influence of these treatments on crop yield and root microbial community shaping. Crop yield was not affected by top dressing and T. harzianum T34, but top dressing significantly increased grain protein and gluten contents. Twenty-seven-week old wheat plants were collected at 12 days after top dressing application and sampled as bulk soil, rhizosphere and root endosphere compartments in order to analyze their bacterial and fungal assemblies by 16S rDNA and ITS2 high-throughput sequencing, respectively. Significant differences for bacterial and fungal richness and diversity were detected among the three compartments with a microbial decline from bulk soil to root endosphere. The most abundant wheat root phyla were Proteobacteria and Actinobacteria for bacteria, and Ascomycota and Basidiomycota for fungi. An enrichment of genera commonly associated with soils subjected to chemical N fertilization was observed: Kaistobacter, Mortierella, and Solicoccozyma in bulk soil, Olpidium in rhizosphere, and Janthinobacterium and Pedobacter in root endosphere. Taxa whose abundance significantly differed among conditions within each compartment were identified. Results show that: (i) single or strain T34-combined application of N top dressing affected to a greater extent the bulk soil bacterial levels than the use of T34 alone; (ii) when N top dressing and T34 were applied in combination, the N fertilizer played a more decisive role in the bacterial microbiome than T34; (iii) many genera of plant beneficial bacteria, negatively affected by N top dressing, were increased by the application of T34 alone; (iv) bulk soil and rhizosphere fungal microbiomes were affected by any of the three treatments assayed; and (v) all treatments reduced Claroideoglomus in bulk soil but the single application of T34 raised the rhizosphere levels of this mycorrhizal fungus.

10.
Respiration ; 99(8): 658-666, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32814339

RESUMO

BACKGROUND: Numerous studies have reported positive effects of exercise training in patients with interstitial lung disease (ILD) on physical capacity and quality of life. However, evidence is rare on the effects of specific forms of training and further pathophysiological mechanisms in these patients. OBJECTIVES: In this multicenter study we aimed to explore the clinical effects of whole-body vibration training (WBVT) in patients with ILD on various outcome measures, including proinflammatory cytokines and myostatin. METHODS: We randomly assigned 26 patients with different forms of multidisciplinary confirmed fibrotic ILDs either to the WBVT group (n = 11; 55% male, 61 ± 14 years old, forced vital capacity 83.2 ± 29.3% predicted, 6-min walking distance [6MWD] 478 ± 79 m) performing 3 months of a standardized training (3 times per week), or to a control training group (CTG, n = 15; 60% male, 63 ± 9 years old, FVC 74.6 ± 20.5% predicted, 6MWD 455 ± 85 m) performing sham WBV training. Training in the two groups was performed on a GalileoTM vibration plate (6-20 vs. 5 Hz). The functional assessments before and after the intervention period included pulmonary function, 6MWD test, chair rise test, ultrasonographic measurement of quadriceps muscle thickness (cross-sectional area), quality of life questionnaires, and serum samples. RESULTS: We observed a significant increase in 6MWD (∆Training = 30 m [12-67], p = 0.024) and a decrease of myostatin (∆Training = -465 pg/mL [-713 to -166], p = 0.008) in the WBVT group. In contrast, no significant differences were observed in the CTG. CONCLUSIONS: The present study demonstrates that WBVT is able to significantly increase 6MWD and decrease myostatin in patients with fibrotic ILDs. Therefore, WBVT seems to be a beneficial and feasible training modality in ILD patients. Clinical Trial Registry: German Clinical Trials Registry (DRKS00012930).


Assuntos
Terapia por Exercício , Doenças Pulmonares Intersticiais/reabilitação , Vibração/uso terapêutico , Idoso , Tolerância ao Exercício/fisiologia , Feminino , Humanos , Interleucina-6/sangue , Doenças Pulmonares Intersticiais/fisiopatologia , Doenças Pulmonares Intersticiais/psicologia , Masculino , Pessoa de Meia-Idade , Miostatina/sangue , Qualidade de Vida , Capacidade Vital , Teste de Caminhada
11.
Front Plant Sci ; 10: 1478, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31803213

RESUMO

The fungal genus Trichoderma includes strains with biocontrol and/or biostimulant potential and is recognized as a source of genes with biotechnological value. In a previous study the Kelch domain protein, encoded by the Thkel1 gene of Trichoderma harzianum T34, was found to confer tolerance to salt stress when expressed in plants of Arabidopsis thaliana. In the present work, we have overexpressed Thkel1 in rapeseed plants in order to generate an additional biotechnological tool for analyzing the role of this gene in Trichoderma-plant interactions. The overexpression of this gene in Brassicaceae plants improves responses to pathogens through the induction of systemic defenses mediated by jasmonic acid, facilitates root colonization by modulating the myrosinase activity, and, as a result, increases plant productivity. These effects were also observed in Thkel1 overexpressing plants subjected to abiotic stress conditions. Additionally, the differences detected in root colonization levels by T. harzianum wild type and Thkel1 silenced transformants between Arabidopsis or rapeseed and tomato plants indicate that ThKEL1 interacts in different ways in Brassicaceae and non-Brassicaceae plants.

12.
Front Microbiol ; 10: 2444, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31749777

RESUMO

Wheat is one of the most important crops worldwide. The use of plant growth promoting microorganisms, such as those of the genus Trichoderma, constitutes an alternative to chemical fertilizers, since they are cheaper and are not detrimental to the environment. However, the interaction between Trichoderma and wheat plants has been scarcely studied, at least at a molecular level. In the present work, a microarray approach was used to study the early transcriptomic changes induced in wheat roots by Trichoderma harzianum, applied alone or in combination with different concentrations of calcium nitrate [Ca(NO3)2], which was last used as nitrogen (N) source. Our results show that T. harzianum causes larger transcriptomic changes than Ca(NO3)2 in wheat roots, and such changes are different when plants are challenged with Trichoderma alone or treated with a combination of T. harzianum and Ca(NO3)2. Overall, T. harzianum activates the expression of defense-related genes at early stages of the interaction with the roots, while this fungus reduces the expression of genes related to plant growth and development. Moreover, the current study in wheat roots, subjected to the different T. harzianum and Ca(NO3)2 combinations, reveals that the number of transcriptomic changes was higher when compared against those caused by the different Ca(NO3)2 concentrations than when it was compared against those caused by T. harzianum. N metabolism gene expression changes were in agreement with the levels of nitrate reductase activity measured in plants from Trichoderma plus Ca(NO3)2 conditions. Results were also concordant with plant phenotypes, which showed reduced growth at early interaction stages when inoculated with T. harzianum or with its combination with Ca(NO3)2 at the lowest dosage. These results were in a good agreement with the recognized role of Trichoderma as an inducer of plant defense.

13.
Sci Rep ; 9(1): 11650, 2019 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-31406170

RESUMO

The family Brassicaceae includes plants that are non-host for arbuscular mycorrhizal fungi (AMF) such as the model plant Arabidopsis thaliana (arabidopsis) and the economically important crop plant Brassica napus (rapeseed). It is well known that Trichoderma species have the ability to colonize the rhizosphere of Brassicaceae plants, promoting growth and development as well as stimulating systemic defenses. The aim of the present work is to ascertain that Brassicaceae plants increase productivity when AMF and Trichoderma are combinedly applied, and how such an effect can be ruled. This simultaneous application of a Trichoderma harzianum biocontrol strain and an AMF formulation produces a significant increase in the colonization by Trichoderma and the presence of AMF in arabidopsis and rapeseed roots, such colonization accompanied by improved productivity in both Brassicaceae species. Expression profiling of defense-related marker genes suggests that the phytohormone salicylic acid plays a key role in the modulation of the root colonization process when both fungi are jointly applied.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Brassica napus/crescimento & desenvolvimento , Micorrizas/fisiologia , Solanum lycopersicum/microbiologia , Trichoderma/fisiologia , Arabidopsis/microbiologia , Brassica napus/microbiologia , Ciclopentanos/metabolismo , Perfilação da Expressão Gênica , Interações entre Hospedeiro e Microrganismos/fisiologia , Oxilipinas/metabolismo , Controle Biológico de Vetores/métodos , Reguladores de Crescimento de Plantas/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Rizosfera , Ácido Salicílico/metabolismo , Simbiose/fisiologia
14.
Rev. esp. drogodepend ; 43(4): 97-101, oct.-dic. 2018.
Artigo em Espanhol | IBECS | ID: ibc-176496

RESUMO

Las denominadas adicciones psicológicas, conductuales o sin sustancia han despertado un interés creciente en los últimos años debido a los problemas que el uso de las nuevas tecnologías plantea en nuestra sociedad. En la actualidad el DSM-5 sólo reconoce el "Juego Patológico", pero cada vez son más los autores que defienden el reconocimiento de otros comportamientos abusivos como el uso de Internet, la telefonía móvil, los juegos online, el sexo, las compras o el ejercicio físico entre otras. En este sentido, la OMS ha propuesto en el borrador de la CIE-11 el reconocimiento del trastorno por juego digital o video juego (gaming disorder). El caso que presentamos trata de una adicción menos conocida: la adicción a consultas del tarot, a través de líneas telefónicas de pago, en una paciente con diagnóstico de trastorno límite de la personalidad y con antecedentes de abuso a sustancias (benzodiazepinas). La escasez de datos publicados en la bibliografía acerca de este tipo de comportamiento nos ha motivado a publicar el caso que les presentamos


So-called psychological, behavioral or substance-free addictions have aroused growing interest in recent years due to the problems posed by the use of new technologies in our society. Currently the DSM-5 only recognizes the Gambling Disorder, but more and more authors defend the recognition of other abusive behaviors such as the use of the Internet, mobile telephony, online games, shopping, sex, exercise and physical exercise, among others. In this respect, in the draft of the ICD-11 the WHO has proposed the recognition of digital games or video-games disorder (Gaming Disorder). The case we present deals with a lesser-known addiction: fortune-telling addiction or addiction to tarot, consulting through calls to pay-telephone lines, in a patient with a diagnosis of borderline personality disorder and with a history of substance abuse (benzodiazepines). The scarcity of data published in the literature about this type of behavior encouraged us to publish the case now being presented


Assuntos
Humanos , Feminino , Idoso , Transtorno da Personalidade Borderline/psicologia , Transtorno da Personalidade Borderline/reabilitação , Comportamento Compulsivo/psicologia , Comportamento Compulsivo/reabilitação
15.
Front Microbiol ; 7: 1182, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27536277

RESUMO

Trichoderma is a fungal genus that includes species that are currently being used as biological control agents and/or as biofertilizers. In addition to the direct application of Trichoderma spp. as biocontrol agents in plant protection, recent studies have focused on the beneficial responses exerted on plants, stimulating the growth, activating the defenses, and/or improving nutrient uptake. The amdS gene, encoding an acetamidase of Aspergillus, has been used as a selectable marker for the transformation of filamentous fungi, including Trichoderma spp., but the physiological effects of the introduction of this gene into the genome of these microorganisms still remains unexplored. No evidence of amdS orthologous genes has been detected within the Trichoderma spp. genomes and the amdS heterologous expression in Trichoderma harzianum T34 did not affect the growth of this fungus in media lacking acetamide. However, it did confer the ability for the fungus to use this amide as a nitrogen source. Although a similar antagonistic behavior was observed for T34 and amdS transformants in dual cultures against Rhizoctonia solani, Botrytis cinerea, and Fusarium oxysporum, a significantly higher antifungal activity was detected in amdS transformants against F. oxysporum, compared to that of T34, in membrane assays on media lacking acetamide. In Trichoderma-tomato interaction assays, amdS transformants were able to promote plant growth to a greater extent than the wild-type T34, although compared with this strain the transformants showed similar capability to colonize tomato roots. Gene expression patterns from aerial parts of 3-week-old tomato plants treated with T34 and the amdS transformants have also been investigated using GeneChip Tomato Genome Arrays. The downregulation of defense genes and the upregulation of carbon and nitrogen metabolism genes observed in the microarrays were accompanied by (i) enhanced growth, (ii) increased carbon and nitrogen levels, and (iii) a higher sensitivity to B. cinerea infections in plants treated with amdS transformants as detected in greenhouse assays. These observations suggest that the increased plant development promoted by the amdS transformants was at expense of defenses.

16.
BJPsych Bull ; 39(4): 196-9, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26755954

RESUMO

Aims and method To evaluate whether involuntary out-patient commitment (OPC) in patients with severe mental disorder reduces their use of hospital services. This is a retrospective case-control study comparing a group of patients on OPC (n = 75) and a control group (n = 75) which was composed of patients whose sociodemographic variables and clinical characteristics were similar to those of the OPC group. Each control case is paired with an OPC case, so the control case must have an involuntary admission in the month that the index OPC case admission occurred. Emergency room visits, admissions and average length of hospital stay over a 2-year follow-up after the initiation of OPC were compared. Results No statistically significant evidence was found in the use of mental healthcare services between the two groups. Different reasons for admission found between the groups limit similarity when comparing the two. Clinical implications The findings cast doubt over the effectiveness of this legal measure to reduce emergency visits, the number of admissions and the length of stay in the hospital.

17.
Plant Sci ; 228: 71-8, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25438787

RESUMO

Many filamentous fungi from the genus Trichoderma are well known for their anti-microbial properties. Certain genes from Trichoderma spp. have been identified and transferred to plants for improving biotic and abiotic stress tolerance, as well for applications in bioremediation. Several Trichoderma genomes have been sequenced and many are in the pipeline, facilitating high throughput gene analysis and increasing the availability of candidate transgenes. This, coupled with improved plant transformation systems, is expected to usher in a new era in plant biotechnology where several genes from these antagonistic fungi can be transferred into plants to achieve enhanced stress tolerance, bioremediation activity, herbicide tolerance, and reduction of phytotoxins. In this review, we illustrate the major achievements made by transforming plants with Trichoderma genes as well as their possible mode of action. Moreover, examples of efficient application of genetically modified plants as biofactories to produce active Trichoderma enzymes are indicated.


Assuntos
Plantas Geneticamente Modificadas/genética , Trichoderma/genética , Parede Celular/metabolismo , Quitinases/genética , Glucanos/metabolismo , Estresse Fisiológico , Transgenes , Trichoderma/enzimologia
18.
Mol Plant Pathol ; 15(8): 823-31, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24684632

RESUMO

Trichoderma is a soil-borne fungal genus that includes species with a significant impact on agriculture and industrial processes. Some Trichoderma strains exert beneficial effects in plants through root colonization, although little is known about how this interaction takes place. To better understand this process, the root colonization of wild-type Arabidopsis and the salicylic acid (SA)-impaired mutant sid2 by a green fluorescent protein (GFP)-marked Trichoderma harzianum strain was followed under confocal microscopy. Trichoderma harzianum GFP22 was able to penetrate the vascular tissue of the sid2 mutant because of the absence of callose deposition in the cell wall of root cells. In addition, a higher colonization of sid2 roots by GFP22 compared with that in Arabidopsis wild-type roots was detected by real-time polymerase chain reaction. These results, together with differences in the expression levels of plant defence genes in the roots of both interactions, support a key role for SA in Trichoderma early root colonization stages. We observed that, without the support of SA, plants were unable to prevent the arrival of the fungus in the vascular system and its spread into aerial parts, leading to later collapse.


Assuntos
Arabidopsis/microbiologia , Raízes de Plantas/microbiologia , Feixe Vascular de Plantas/microbiologia , Ácido Salicílico/farmacologia , Trichoderma/fisiologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Contagem de Colônia Microbiana , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Glucanos/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Desenvolvimento Vegetal/efeitos dos fármacos , Feixe Vascular de Plantas/efeitos dos fármacos , Reação em Cadeia da Polimerase em Tempo Real , Trichoderma/efeitos dos fármacos
19.
Physiol Plant ; 150(3): 446-62, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24117983

RESUMO

The rooting of stem cuttings is a common vegetative propagation practice in many ornamental species. A detailed analysis of the morphological changes occurring in the basal region of cultivated carnation cuttings during the early stages of adventitious rooting was carried out and the physiological modifications induced by exogenous auxin application were studied. To this end, the endogenous concentrations of five major classes of plant hormones [auxin, cytokinin (CK), abscisic acid, salicylic acid (SA) and jasmonic acid] and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid were analyzed at the base of stem cuttings and at different stages of adventitious root formation. We found that the stimulus triggering the initiation of adventitious root formation occurred during the first hours after their excision from the donor plant, due to the breakdown of the vascular continuum that induces auxin accumulation near the wounding. Although this stimulus was independent of exogenously applied auxin, it was observed that the auxin treatment accelerated cell division in the cambium and increased the sucrolytic activities at the base of the stem, both of which contributed to the establishment of the new root primordia at the stem base. Further, several genes involved in auxin transport were upregulated in the stem base either with or without auxin application, while endogenous CK and SA concentrations were specially affected by exogenous auxin application. Taken together our results indicate significant crosstalk between auxin levels, stress hormone homeostasis and sugar availability in the base of the stem cuttings in carnation during the initial steps of adventitious rooting.


Assuntos
Metabolismo dos Carboidratos , Dianthus/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Raízes de Plantas/metabolismo , Caules de Planta/metabolismo , Ácido Abscísico/metabolismo , Aminoácidos Cíclicos/metabolismo , Citocininas/metabolismo , Dianthus/efeitos dos fármacos , Dianthus/genética , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ácidos Indolacéticos/metabolismo , Ácidos Indolacéticos/farmacologia , Isopenteniladenosina/análogos & derivados , Isopenteniladenosina/metabolismo , Microscopia Eletrônica de Varredura , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/ultraestrutura , Caules de Planta/genética , Caules de Planta/ultraestrutura , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Salicilatos/metabolismo , Técnicas de Cultura de Tecidos
20.
Int. microbiol ; 16(2): 69-80, jun. 2013. ilus
Artigo em Inglês | IBECS | ID: ibc-126421

RESUMO

Trichoderma is a fungal genus of cosmopolitan distribution and high biotechnological value, with several species currently used as biological control agents. Additionally, the enzyme systems of the fungus are widely applied in industry. Species of Trichoderma protect plants against the attack of soil-borne plant pathogens by competing for nutrients and inhibiting or killing plant pathogenic fungi and oomycetes, through the production of antibiotics and/or hydrolytic enzymes. In addition to the role of Trichoderma spp. as biocontrol agents, they have other beneficial effects on plants, including the stimulation of plant defenses and the promotion of plant growth. In this review, we focus on the complex plant defense signaling network that allows the recognition of fungi as non-hostile microbes, including microbial-associated molecular patterns (MAMPs), damage associated molecular patterns (DAMPs) and secreted elicitors. We also examine how fungal interactions with plant receptors can activate induced resistance by priming and balancing plant defense and growth responses. Our observations are integrated into a model describing Trichoderma-plant hormone signaling network interactions (AU)


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Assuntos
Trichoderma , Desenvolvimento Vegetal , Plantas/microbiologia , Simbiose , Arabidopsis/crescimento & desenvolvimento , Reguladores de Crescimento de Plantas/análise , Fungos/crescimento & desenvolvimento
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