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1.
Int J Mol Sci ; 23(16)2022 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-36012567

RESUMO

Fungal pathogens capable of producing mycotoxins are one of the main threats to the cultivation of cereals and the safety of the harvested kernels. Improving the resistance of crops to fungal disease and accumulation of mycotoxins is therefore a crucial issue. Achieving this goal requires a deep understanding of plant defense mechanisms, most of them involving specialized metabolites. However, while numerous studies have addressed the contribution of phenylpropanoids and carotenoids to plant chemical defense, very few have dealt with tocochromanols. Tocochromanols, which encompass tocopherols and tocotrienols and constitute the vitamin E family, are widely distributed in cereal kernels; their biosynthetic pathway has been extensively studied with the aim to enrich plant oils and combat vitamin E deficiency in humans. Here we provide strong assumptions arguing in favor of an involvement of tocochromanols in plant-fungal pathogen interactions. These assumptions are based on both direct effects resulting from their capacity to scavenge reactive oxygen species, including lipid peroxyl radicals, on their potential to inhibit fungal growth and mycotoxin yield, and on more indirect effects mainly based on their role in plant protection against abiotic stresses.


Assuntos
Micotoxinas , Tocotrienóis , Grão Comestível/metabolismo , Humanos , Estresse Fisiológico , Tocoferóis/metabolismo , Tocotrienóis/metabolismo
2.
J Agric Food Chem ; 2023 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36780464

RESUMO

Fusarium graminearum is the causal agent of Gibberella ear rot (GER) in maize, a devastating fungal disease resulting in yield reduction and contamination of grains with type B trichothecene (TCTB) mycotoxins. Reducing GER damage requires the implementation of an integrated management strategy in which the use of resistant maize genotypes is a key factor. The present study aimed at providing new phenotyping tools to improve breeding pipelines by investigating the yet understudied contribution of carotenoids to GER resistance. Here, we demonstrated for the first time the efficiency of carotenoid extracts from various maize genotypes to inhibit the production of TCTB by F. graminearum. We further suggested that zeaxanthin could be a key actor of this inhibition efficiency, notably via a negative transcriptional control of several biosynthetic genes of the TCTB pathway. Besides, we demonstrated that zeaxanthin treatments led to profound perturbations in the fungal redox homeostasis by affecting the expression of key genes encoding ROS detoxifying enzymes, several of them being involved in F. graminearum virulence during plant infection. Altogether, our data support the contribution of carotenoids to the mechanisms employed by maize to counteract F. graminearum infection and its production of TCTB.

3.
mBio ; 14(1): e0287822, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36533926

RESUMO

Understanding the genetic diversity and mechanisms underlying genetic variation in pathogen populations is crucial to the development of effective control strategies. We investigated the genetic diversity and reproductive biology of Colletotrichum graminicola isolates which infect maize by sequencing the genomes of 108 isolates collected from 14 countries using restriction site-associated DNA sequencing (RAD-seq) and whole-genome sequencing (WGS). Clustering analyses based on single-nucleotide polymorphisms revealed three genetic groups delimited by continental origin, compatible with short-dispersal of the pathogen and geographic subdivision. Intra- and intercontinental migration was observed between Europe and South America, likely associated with the movement of contaminated germplasm. Low clonality, evidence of genetic recombination, and high phenotypic diversity were detected. We show evidence that, although it is rare (possibly due to losses of sexual reproduction- and meiosis-associated genes) C. graminicola can undergo sexual recombination. Our results support the hypotheses that intra- and intercontinental pathogen migration and genetic recombination have great impacts on the C. graminicola population structure. IMPORTANCE Plant pathogens cause significant reductions in yield and crop quality and cause enormous economic losses worldwide. Reducing these losses provides an obvious strategy to increase food production without further degrading natural ecosystems; however, this requires knowledge of the biology and evolution of the pathogens in agroecosystems. We employed a population genomics approach to investigate the genetic diversity and reproductive biology of the maize anthracnose pathogen (Colletotrichum graminicola) in 14 countries. We found that the populations are correlated with their geographical origin and that migration between countries is ongoing, possibly caused by the movement of infected plant material. This result has direct implications for disease management because migration can cause the movement of more virulent and/or fungicide-resistant genotypes. We conclude that genetic recombination is frequent (in contrast to the traditional view of C. graminicola being mainly asexual), which strongly impacts control measures and breeding programs aimed at controlling this disease.


Assuntos
Colletotrichum , Zea mays , Metagenômica , Ecossistema , Sequência de Bases , Doenças das Plantas , Variação Genética
4.
Hum Gene Ther ; 15(11): 1065-76, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15610607

RESUMO

Nine patients with Duchenne or Becker muscular dystrophy were injected via the radialis muscle with a full-length human dystrophin plasmid, either once with 200 or 600 microg of DNA or twice, 2 weeks apart, with 600 microg of DNA. In the biopsies taken 3 weeks after the initial injection, the vector was detected at the injection site in all patients. Immunohistochemistry and nested reverse transcription-polymerase chain reaction indicated dystrophin expression in six of nine patients. The level of expression was low (up to 6% weak, but complete sarcolemmal dystrophin staining, and up to 26% partial sarcolemmal labeling). No side effects were observed, nor any cellular or humoral anti-dystrophin responses. These results suggest that exogenous dystrophin expression can be obtained in Duchenne/Becker patients after intramuscular transfer of plasmid, without adverse effects, hence paving the way for future developments in gene therapy of hereditary muscular diseases.


Assuntos
Distrofina/genética , Terapia Genética/métodos , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/terapia , Adolescente , Adulto , Biópsia , Estudos de Coortes , Distrofina/biossíntese , Técnicas de Transferência de Genes , Vetores Genéticos , Teste de Histocompatibilidade , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Modelos Genéticos , Músculo Esquelético/metabolismo , Músculos/metabolismo , Músculos/patologia , Plasmídeos/metabolismo , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo
5.
J Soc Biol ; 199(1): 29-32, 2005.
Artigo em Francês | MEDLINE | ID: mdl-16114261

RESUMO

This is the first gene transfer trial in Duchenne/Becker patients. The aim of the study was to provide evidence on transgene expression and safety of the intramuscular administration of a plasmid containing a full-length dystrophin CDNA. Nine Duchenne/Becker patients, distributed in three cohorts of three patients, were injected into their radialis muscles either once with 200 microg (first cohort) or 600 microg (second cohort) or twice, two weeks apart, with 600 microg plasmidic DNA (third cohort). The patients were enrolled sequentially upon evaluation of the data by an independant pilot committee. In the biopsies taken three weeks after the initial injection from the injected site, the plasmid was detected in all patients. An exogenous dystrophin expression was found in 6/9 patients. The level of expression was low, up to 6 % of weak complete sarcolemmal labelling, and up to 26% of partial sarcolemmal staining. Dystrophin in RNAs were detected by nested RT-PCR in five out of the six biopsies with exogenous dystrophin-positive fibers. Interestingly, neither humoral or cellular antidystrophin responses were observed. No local or general adverse effects were seen. This paves the way for future developments in gene therapy in hereditary muscle diseases, and specifically in Duchenne/Becker myopathies.


Assuntos
DNA/administração & dosagem , Distrofina/genética , Terapia Genética , Distrofia Muscular de Duchenne/terapia , Biópsia , DNA/genética , Expressão Gênica , Humanos , Injeções Intramusculares , Masculino , Músculo Esquelético/química , Plasmídeos/genética , RNA/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa
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