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1.
Phytopathology ; 114(7): 1490-1501, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38968142

RESUMO

Early detection of rice blast disease is pivotal to ensure rice yield. We collected in situ images of rice blast and constructed a rice blast dataset based on variations in lesion shape, size, and color. Given that rice blast lesions are small and typically exhibit round, oval, and fusiform shapes, we proposed a small object detection model named GCPDFFNet (global context-based parallel differentiation feature fusion network) for rice blast recognition. The GCPDFFNet model has three global context feature extraction modules and two parallel differentiation feature fusion modules. The global context modules are employed to focus on the lesion areas; the parallel differentiation feature fusion modules are used to enhance the recognition effect of small-sized lesions. In addition, we proposed the SCYLLA normalized Wasserstein distance loss function, specifically designed to accelerate model convergence and improve the detection accuracy of rice blast disease. Comparative experiments were conducted on the rice blast dataset to evaluate the performance of the model. The proposed GCPDFFNet model outperformed the baseline network CenterNet, with a significant increase in mean average precision from 83.6 to 95.4% on the rice blast test set while maintaining a satisfactory frames per second drop from 147.9 to 122.1. Our results suggest that the GCPDFFNet model can accurately detect in situ rice blast disease while ensuring the inference speed meets the real-time requirements.


Assuntos
Oryza , Doenças das Plantas , Processamento de Imagem Assistida por Computador/métodos , Algoritmos
2.
Chemosphere ; 356: 141904, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38582174

RESUMO

Rice blast, an extremely destructive disease caused by the filamentous fungal pathogen Magnaporthe oryzae, poses a global threat to the production of rice (Oryza sativa L.). The emerging trend of reducing dependence on chemical fungicides for crop protection has increased interest in exploring bioformulated nanomaterials as a sustainable alternative antimicrobial strategy for effectively managing plant diseases. Herein, we used physiomorphological, transcriptomic, and metabolomic methods to investigate the toxicity and molecular action mechanisms of moringa-chitosan nanoparticles (M-CNPs) against M. oryzae. Our results demonstrate that M-CNPs exhibit direct antifungal properties by impeding the growth and conidia formation of M. oryzae in a concentration-dependent manner. Propidium iodide staining indicated concentration-dependent significant apoptosis (91.33%) in the fungus. Ultrastructural observations revealed complete structural damage in fungal cells treated with 200 mg/L M-CNPs, including disruption of the cell wall and destruction of internal organelles. Transcriptomic and metabolomic analyses revealed the intricate mechanism underlying the toxicity of M-CNPs against M. oryzae. The transcriptomics data indicated that exposure to M-CNPs disrupted various processes integral to cell membrane biosynthesis, aflatoxin biosynthesis, transcriptional regulation, and nuclear integrity in M. oryzae., emphasizing the interaction between M-CNPs and fungal cells. Similarly, metabolomic profiling demonstrated that exposure to M-CNPs significantly altered the levels of several key metabolites involved in the integral components of metabolic pathways, microbial metabolism, histidine metabolism, citrate cycle, and lipid and protein metabolism in M. oryzae. Overall, these findings demonstrated the potent antifungal action of M-CNPs, with a remarkable impact at the physiological and molecular level, culminating in substantial apoptotic-like fungal cell death. This research provides a novel perspective on investigating bioformulated nanomaterials as antifungal agents for plant disease control.


Assuntos
Quitosana , Nanopartículas , Oryza , Doenças das Plantas , Transcriptoma , Quitosana/química , Nanopartículas/toxicidade , Nanopartículas/química , Transcriptoma/efeitos dos fármacos , Oryza/microbiologia , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Metabolômica , Antifúngicos/toxicidade , Antifúngicos/farmacologia , Ascomicetos/efeitos dos fármacos , Ascomicetos/genética
3.
Int J Mol Sci ; 25(6)2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38542408

RESUMO

Septins play a key regulatory role in cell division, cytokinesis, and cell polar growth of the rice blast fungus (Magnaporthe oryzae). We found that the organization of the septin ring, which is essential for appressorium-mediated infection in M. oryzae, requires long-chain fatty acids (LCFAs), which act as mediators of septin organization at membrane interfaces. However, it is unclear how septin ring formation and LCFAs regulate the pathogenicity of the rice blast fungus. In this study, a novel protein was named MoLfa1 because of its role in LCFAs utilization. MoLfa1 affects the utilization of LCFAs, lipid metabolism, and the formation of the septin ring by binding with phosphatidylinositol phosphates (PIPs), thereby participating in the construction of penetration pegs of M. oryzae. In addition, MoLfa1 is localized in the endoplasmic reticulum (ER) and interacts with the ER-related protein MoMip11 to affect the phosphorylation level of Mps1. (Mps1 is the core protein in the MPS1-MAPK pathway.) In conclusion, MoLfa1 affects conidia morphology, appressorium formation, lipid metabolism, LCFAs utilization, septin ring formation, and the Mps1-MAPK pathway of M. oryzae, influencing pathogenicity.


Assuntos
Ascomicetos , Magnaporthe , Oryza , Septinas/metabolismo , Proteínas Fúngicas/metabolismo , Magnaporthe/fisiologia , Citoesqueleto/metabolismo , Oryza/metabolismo , Doenças das Plantas/microbiologia , Esporos Fúngicos/metabolismo , Regulação Fúngica da Expressão Gênica
4.
Carbohydr Polym ; 334: 122023, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38553222

RESUMO

Rice blast disease (RBD) caused by Magnaporthe oryzae, threaten food security by cutting agricultural output. Nano agrochemicals are now perceived as sustainable, cost-effective alternatives to traditional pesticides. This study investigated bioformulation of moringa chitosan nanoparticles (M-CsNPs) and their mechanisms for suppressing RBD while minimizing toxic effects on the microenvironment. M-CsNPs, sized 46 nm with semi-spherical morphology, significantly suppressed pathogen growth, integrity, and colonization at 200 mg L-1in vitro. Greenhouse tests with foliar exposure to the same concentration resulted in a substantial 77.7 % reduction in RBD, enhancing antioxidant enzyme activity and plant health. Furthermore, M-CsNPs improved photosynthesis, gas exchange, and the nutritional profile of diseased rice plants. RNA-seq analysis highlighted upregulated defense-related genes in treated rice plants. Metagenomic study showcased reshaping of the rice microbiome, reducing Magnaporthe abundance by 93.5 %. Both healthy and diseased rice plants showed increased microbial diversity, particularly favoring specific beneficial species Thiobacillus, Nitrospira, Nocardioides, and Sphingomicrobium in the rhizosphere and Azonexus, Agarivorans, and Bradyrhizobium in the phyllosphere. This comprehensive study unravels the diverse mechanisms by which M-CsNPs interact with plants and pathogens, curbing M. oryzae damage, promoting plant growth, and modulating the rice microbiome. It underscores the significant potential for effective plant disease management.


Assuntos
Quitosana , Microbiota , Oryza , Resistência à Doença , Oryza/genética , Quitosana/farmacologia , Bactérias , Doenças das Plantas/prevenção & controle
5.
Trends Microbiol ; 32(4): 319-320, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38395702

RESUMO

The delicate balance between soil micronutrients and the phytobeneficial microbiome is crucial for maintaining soil-plant health. Recently, Dai et al. established a correlation between elemental micronutrients and the soil microbiome that regulates plant quality and productivity, offering innovative and sustainable solutions to increase agricultural production in a changing climate.


Assuntos
Microbiota , Solo , Micronutrientes/análise , Plantas , Agricultura , Microbiologia do Solo
6.
Cell Commun Signal ; 22(1): 19, 2024 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-38195499

RESUMO

The cell cycle is pivotal to cellular differentiation in plant pathogenic fungi. Cell wall integrity (CWI) signaling plays an essential role in coping with cell wall stress. Autophagy is a degradation process in which cells decompose their components to recover macromolecules and provide energy under stress conditions. However, the specific association between cell cycle, autophagy and CWI pathway remains unclear in model pathogenic fungi Magnaporthe oryzae. Here, we have identified MoSwe1 as the conserved component of the cell cycle in the rice blast fungus. We have found that MoSwe1 targets MoMps1, a conserved critical MAP kinase of the CWI pathway, through protein phosphorylation that positively regulates CWI signaling. The CWI pathway is abnormal in the ΔMoswe1 mutant with cell cycle arrest. In addition, we provided evidence that MoSwe1 positively regulates autophagy by interacting with MoAtg17 and MoAtg18, the core autophagy proteins. Moreover, the S phase initiation was earlier, the morphology of conidia and appressoria was abnormal, and septum formation and glycogen degradation were impaired in the ΔMoswe1 mutant. Our research defines that MoSWE1 regulation of G1/S transition, CWI pathway, and autophagy supports its specific requirement for appressorium development and virulence in plant pathogenic fungi. Video Abstract.


Assuntos
Ascomicetos , Ciclo Celular , Autofagia , Parede Celular
7.
Mol Plant ; 17(2): 258-276, 2024 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-38069474

RESUMO

The growth-promoting hormones brassinosteroids (BRs) and their key signaling component BZR1 play a vital role in balancing normal growth and defense reactions. Here, we discovered that BRs and OsBZR1 upregulated sakuranetin accumulation and conferred basal defense against Magnaporthe oryzae infection under normal conditions. Resource shortages, including phosphate (Pi) deficiency, potentially disrupt this growth-defense balance. OsSPX1 and OsSPX2 have been reported to sense Pi concentration and interact with the Pi signal mediator OsPHR2, thus regulating Pi starvation responses. In this study, we discovered that OsSPX1/2 interacts with OsBZR1 in both Pi-sufficient and Pi-deficient conditions, inhibiting BR-responsive genes. When Pi is sufficient, OsSPX1/2 is captured by OsPHR2, enabling most of OsBZR1 to promote plant growth and maintain basal resistance. In response to Pi starvation, more OsSPX1/2 is released from OsPHR2 to inhibit OsBZR1 activity, resulting in slower growth. Collectively, our study reveals that the OsBZR1-SPX1/2 module balances the plant growth-immunity trade-off in response to Pi availability.


Assuntos
Oryza , Proteínas de Plantas , Proteínas de Plantas/metabolismo , Oryza/genética , Fosfatos/metabolismo , Brassinosteroides , Regulação da Expressão Gênica de Plantas
8.
PLoS Pathog ; 19(11): e1011733, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37943805

RESUMO

Sphingolipids are critically significant in a range of biological processes in animals, plants, and fungi. In mammalian cells, they serve as vital components of the plasma membrane (PM) in maintaining its structure, tension, and fluidity. They also play a key role in a wide variety of biological processes, such as intracellular signal transduction, cell polarization, differentiation, and migration. In plants, sphingolipids are important for cell development and for cell response to environmental stresses. In pathogenic fungi, sphingolipids are crucial for the initiation and the development of infection processes afflicting humans. However, our knowledge on the metabolism and function of the sphingolipid metabolic pathway of pathogenic fungi affecting plants is still very limited. In this review, we discuss recent developments on sphingolipid pathways of plant pathogenic fungi, highlighting their uniqueness and similarity with plants and animals. In addition, we discuss recent advances in the research and development of fungal-targeted inhibitors of the sphingolipid pathway, to gain insights on how we can better control the infection process occurring in plants to prevent or/and to treat fungal infections in crops.


Assuntos
Plantas , Esfingolipídeos , Humanos , Animais , Esfingolipídeos/química , Esfingolipídeos/metabolismo , Plantas/metabolismo , Fungos/metabolismo , Transdução de Sinais/fisiologia , Membrana Celular/metabolismo , Mamíferos
9.
Mitochondrial DNA B Resour ; 8(10): 1036-1040, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37799450

RESUMO

The complete mitochondrial genome of Pyricularia oryzae Cavara 1892 strain Guy11 is 34,865 bp in length (GenBank accession number OP095391), containing 29 tRNA genes, 2 rRNA genes, and 15 protein-coding genes (PCGs). The gene order and orientation are novel compared to other Sordariomycetes species with sequenced mitogenomes in the GenBank database. Phylogenetic analysis suggests that P. oryzae Guy11 and 19 other Sordariomycetes species form a monophyletic group. The complete mitochondrial sequence of P. oryzae Guy11 will be a valuable resource for species identification, population genetics, phylogenetics, and comparative genomics studies in Sordariomycetes and Magnaporthales.

10.
Molecules ; 28(18)2023 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-37764443

RESUMO

In fungi, the methylcitrate cycle converts cytotoxic propionyl-coenzyme A (CoA) to pyruvate, which enters gluconeogenesis. The glyoxylate cycle converts acetyl-CoA to succinate, which enters gluconeogenesis. The tricarboxylic acid cycle is a central carbon metabolic pathway that connects the methylcitrate cycle, the glyoxylate cycle, and other metabolisms for lipids, carbohydrates, and amino acids. Fungal citrate synthase and 2-methylcitrate synthase as well as isocitrate lyase and 2-methylisocitrate lyase, each evolved from a common ancestral protein. Impairment of the methylcitrate cycle leads to the accumulation of toxic intermediates such as propionyl-CoA, 2-methylcitrate, and 2-methylisocitrate in fungal cells, which in turn inhibits the activity of many enzymes such as dehydrogenases and remodels cellular carbon metabolic processes. The methylcitrate cycle and the glyoxylate cycle synergistically regulate carbon source utilization as well as fungal growth, development, and pathogenic process in pathogenic fungi.


Assuntos
Ciclo do Ácido Cítrico , Fungos , Acetilcoenzima A , Fungos/metabolismo , Carbono/metabolismo , Glioxilatos/metabolismo
11.
Nanoscale ; 15(26): 11179-11189, 2023 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-37340955

RESUMO

Non-contact optical temperature sensors are highly sought after by researchers due to their satisfactory temperature resolution (δ(T) < 0.1 °C), high relative thermal sensitivity (Sr > 1% °C-1), fast temporal response (t < 0.1 s), and long-term optical stability. In this study, NaYF4:Yb3+/Ho3+/Tm3+ upconversion nanoparticles were prepared by a solvothermal method, and their crystal structure, microscopic morphology, and luminescence mechanism, together with the temperature sensing properties of the specimens, were investigated. Under 980 nm laser excitation, the specimens exhibited strong upconversion luminescence, and the emission peaks corresponded to the characteristic energy level jumps of Ho3+ and Tm3+, respectively. The temperature-dependent luminescence spectra of the samples were investigated based on the fluorescence intensity ratio (FIR) technique over a temperature gradient of 295-495 K. The samples are based on thermally coupled energy levels (TCLs: 1G4(1,2) → 3H6(Tm3+)) and non-thermally coupled energy levels (NTCLs: 3F3 → 3H6(Tm3+) and 5F3 → 5I8(Ho3+), 3F3 → 3H6(Tm3+) and 1G4 → 3H6(Tm3+), 3F3 → 3H6(Tm3+) and 5F5 → 5I8(Ho3+), 3F3 → 3H6(Tm3+) and 5F4 → 5I8(Ho3+)) for temperature sensing performance. The maximum absolute sensitivity (Sa), relative sensitivity (Sr), and minimum temperature resolution δ(T) were found to be 0.0126 K-1 (495 K), 1.7966% K-1 (345 K), and 0.0167 K, respectively, which are better than those of most sensing materials, and the simultaneous action of multiple coupling energy levels can further improve the temperature precision. This study indicates that the sample has a good value for optical temperature measurement and also provides new ideas for the exploration of other high-quality optical temperature sensing materials.

12.
Mol Plant Pathol ; 24(10): 1256-1272, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37357820

RESUMO

Magnaporthe oryzae is a pathogenic fungus that seriously harms rice production. Phosphatases and carbon metabolism play crucial roles in the growth and development of eukaryotes. However, it remains unclear how serine/threonine phosphatases regulate the catabolism of triglycerides, a major form of stored lipids. In this study, we identified a serine/threonine protein phosphatase regulatory subunit, Smek1, which is required for the growth, conidiation, and virulence of M. oryzae. Deletion of SMEK1 led to defects in the utilization of lipids, arabinose, glycerol, and ethanol. In glucose medium, the expression of genes involved in lipolysis, long-chain fatty acid degradation, ß-oxidation, and the glyoxylate cycle increased in the Δsmek1 mutant, which is consistent with ΔcreA in which a carbon catabolite repressor CREA was deleted. In lipid medium, the expression of genes involved in long-chain fatty acid degradation, ß-oxidation, the glyoxylate cycle, and utilization of arabinose, ethanol, or glycerol decreased in the Δsmek1 mutant, which is consistent with Δcrf1 in which a transcription activator CRF1 required for carbon metabolism was deleted. Lipase activity, however, increased in the Δsmek1 mutant in both glucose and lipid media. Moreover, Smek1 directly interacted with CreA and Crf1, and dephosphorylated CreA and Crf1 in vivo. The phosphatase Smek1 is therefore a dual-function regulator of the lipid and carbohydrate metabolism, and controls fungal development and virulence by coordinating the functions of CreA and Crf1 in carbon catabolite repression (CCR) and derepression (CCDR).


Assuntos
Magnaporthe , Oryza , Lipólise , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Arabinose , Glicerol , Fosfoproteínas Fosfatases/genética , Fosfoproteínas Fosfatases/metabolismo , Carbono/metabolismo , Glucose/metabolismo , Glioxilatos , Ácidos Graxos , Treonina/genética , Treonina/metabolismo , Lipídeos , Serina/metabolismo , Regulação Fúngica da Expressão Gênica , Oryza/microbiologia , Doenças das Plantas/microbiologia , Esporos Fúngicos
13.
J Fungi (Basel) ; 9(4)2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37108949

RESUMO

Anthracnose is one of the most widespread and destructive diseases in grapes. Grape anthracnose can be caused by various Colletotrichum species, such as Colletotrichum gloeosporioides and Colletotrichum cuspidosporium. In recent years, Colletotrichum aenigma was reported as a causal agent of Grape anthracnose in China and South Korea. Peroxisome is an important organelle in eukaryotes, which plays a very important role in the growth, development, and pathogenicity of several plant-pathogenic fungal species i, but it has not been reported in C. aenigma. In this work, the peroxisome of C. aenigma was labeled with a fluorescent protein, using green fluorescent protein (GFP) and red fluorescent protein (DsRED and mCherry) as reporter genes. Via Agrobacterium tumefaciens-mediated transformation (AtMT), two fluorescent fusion vectors to mark the peroxisomes, with GFP and DsRED, respectively, were introduced into a wild-type strain of C. aenigma. In the transformants, bright dots of green or red fluorescence in hyphae and spores could be seen in the strains labeled peroxisome. The nuclei labeled by the same method showed bright round fluorescent spots. In addition, we also combined fluorescent protein labeling with chemical staining to show the localization more clearly. The ideal peroxisome and nuclear fluorescence-labeled C. aenigma strain was obtained, which provided a reference for the study of its growth, development, and pathogenicity.

14.
Autophagy ; 19(8): 2353-2371, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36803211

RESUMO

Macroautophagy/autophagy is an evolutionarily conserved biological process among eukaryotes that degrades unwanted materials such as protein aggregates, damaged mitochondria and even viruses to maintain cell survival. Our previous studies have demonstrated that MoVast1 acts as an autophagy regulator regulating autophagy, membrane tension, and sterol homeostasis in rice blast fungus. However, the detailed regulatory relationships between autophagy and VASt domain proteins remain unsolved. Here, we identified another VASt domain-containing protein, MoVast2, and further uncovered the regulatory mechanism of MoVast2 in M. oryzae. MoVast2 interacted with MoVast1 and MoAtg8, and colocalized at the PAS and deletion of MoVAST2 results in inappropriate autophagy progress. Through TOR activity analysis, sterols and sphingolipid content detection, we found high sterol accumulation in the ΔMovast2 mutant, whereas this mutant showed low sphingolipids and low activity of both TORC1 and TORC2. In addition, MoVast2 colocalized with MoVast1. The localization of MoVast2 in the MoVAST1 deletion mutant was normal; however, deletion of MoVAST2 leads to mislocalization of MoVast1. Notably, the wide-target lipidomic analyses revealed significant changes in sterols and sphingolipids, the major PM components, in the ΔMovast2 mutant, which was involved in lipid metabolism and autophagic pathways. These findings confirmed that the functions of MoVast1 were regulated by MoVast2, revealing that MoVast2 combined with MoVast1 maintained lipid homeostasis and autophagy balance by regulating TOR activity in M. oryzae.


Assuntos
Magnaporthe , Oryza , Autofagia/genética , Magnaporthe/genética , Magnaporthe/metabolismo , Oryza/genética , Oryza/microbiologia , Homeostase , Esfingolipídeos , Esteróis/metabolismo , Lipídeos , Proteínas Fúngicas/metabolismo , Doenças das Plantas/microbiologia
15.
Sheng Wu Gong Cheng Xue Bao ; 39(2): 459-471, 2023 Feb 25.
Artigo em Chinês | MEDLINE | ID: mdl-36847083

RESUMO

Plant diseases and insect pests threaten the safety of crop production greatly. Traditional methods for pest management are challenged by the problems such as environmental pollution, off-target effects, and resistance of pathogens and insects. New biotechnology-based strategies for pest control are expected to be developed. RNA interference (RNAi) is an endogenous process of gene regulation, which has been widely used to study the gene functions in various organisms. In recent years, RNAi-based pest management has received increasing attention. The effective delivery of the exogenous interference RNA into the targets is a key step in RNAi-mediated plant diseases and pest control. Considerable advances were made on the mechanism of RNAi, and various RNA delivery systems were developed for efficient pest control. Here we review the latest advances on mechanisms and influencing factors of RNA delivery, summarize the strategies of exogenous RNA delivery in RNAi-mediated pest control, and highlight the advantages of nanoparticle complexes in dsRNA delivery.


Assuntos
Insetos , Controle de Pragas , Animais , Interferência de RNA , Insetos/genética , RNA de Cadeia Dupla , Regulação da Expressão Gênica
16.
Food Chem ; 402: 134159, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36137380

RESUMO

Few reports are on the application of cold plasma (CP) for mold and mycotoxin control in grain. The aim of this study was to evaluate the viability of CP for mycotoxin and mold control in rice grain. Rice grains artificially contaminated with molds or mycotoxins were subjected to CP treatment. The microbial activities of Aspergillus niger, Rhizopus oryzae, Penicillium verrucosum and Fusarium graminearum were significantly inhibited by CP treatment. The maximal reduction of DON and OTA were 61.25 % and 55.64 %, respectively. The electrical conductivity and malondialdehyde content in rice grain increased at most by 30.14 % and 103.27 %, respectively. The seed germination reduced significantly when treatment time reached 8 min. The major nutrients of rice grain were not affected except for prolamine, which was generally consistent with the results of electron microscopy and Fourier-transform infrared analysis. Cold plasma is a promising method for mold and mycotoxin control in rice grain.


Assuntos
Fusarium , Micotoxinas , Oryza , Gases em Plasma , Micotoxinas/análise , Descontaminação , Grão Comestível/química , Fungos , Malondialdeído , Fenilpropanolamina , Contaminação de Alimentos/análise
17.
Int J Mol Sci ; 23(21)2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36362450

RESUMO

Rice is an important food crop all over the world. It can be infected by the rice blast fungus Magnaporthe oryzae, which results in a significant reduction in rice yield. The infection mechanism of M. oryzae has been an academic focus for a long time. It has been found that G protein, AMPK, cAMP-PKA, and MPS1-MAPK pathways play different roles in the infection process. Recently, the function of TOR signaling in regulating cell growth and autophagy by receiving nutritional signals generated by plant pathogenic fungi has been demonstrated, but its regulatory mechanism in response to the nutritional signals remains unclear. In this study, a yeast amino acid permease homologue MoGap1 was identified and a knockout mutant of MoGap1 was successfully obtained. Through a phenotypic analysis, a stress analysis, autophagy flux detection, and a TOR activity analysis, we found that the deletion of MoGap1 led to a sporulation reduction as well as increased sensitivity to cell wall stress and carbon source stress in M. oryzae. The ΔMogap1 mutant showed high sensitivity to the TOR inhibitor rapamycin. A Western blot analysis further confirmed that the TOR activity significantly decreased, which improved the level of autophagy. The results suggested that MoGap1, as an upstream regulator of TOR signaling, regulated autophagy and responded to adversities such as cell wall stress by regulating the TOR activity.


Assuntos
Magnaporthe , Oryza , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Oryza/metabolismo , Autofagia/genética , Saccharomyces cerevisiae/metabolismo , Sistemas de Transporte de Aminoácidos/metabolismo , Doenças das Plantas/genética , Doenças das Plantas/microbiologia
18.
Front Microbiol ; 13: 1017352, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36386634

RESUMO

Brown leaf spot on tobacco is a serious fungal disease caused by Alternaria alternata. Peroxisomes are organelles playing an important role in the development and infection of plant pathogenic fungi. But, until now, there is no report on the peroxisome dynamics during the conidia germination of A. alternata. To evaluate the roles of peroxisome in the development of the fungus, in the present work, an enhanced green fluorescent protein (eGFP) cassette tagged with peroxisome targeting signal 2 (PTS2) was integrated into A. alternata to label the organelles, and an eGFP cassette carrying a nuclear located signal (NLS) was performed parallelly. The transformants containing the fusions emitted fluorescence in punctate patterns. The fluorescence of eGFP-PTS2 was distributed exactly in the peroxisomes while those of eGFP-NLS were located in the nucleus. Typical AaGB transformants were selected to be investigated for the peroxisome dynamics. The results showed that during spore germination, the number of peroxisomes in the spores decreased gradually, but increased in the germ tubes. In addition, when the transformants were cultured on lipid media, the numbers of peroxisomes increased significantly, and in a larger portion, present in striped shapes. These findings give some clues for understanding the peroxisomal functions in the development of A. alternata.

19.
J Fungi (Basel) ; 8(10)2022 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-36294571

RESUMO

Trichophyton mentagrophytes is an important zoonotic dermatophyte, which seriously harms the skin of humans and animals. Chemical drugs are generally used for the prevention and treatment of the disease caused by T. mentagrophytes. Discovering new compounds from natural products is an important approach for new drug development. Trichoderma includes a variety of fungal species used for biological control of phytopathogenic fungi. However, the antifungal effects of Trichoderma and their metabolites on zoonotic fungal pathogens are largely unknown. Here, the effect of trichodermin, a metabolite derived from the plant endophytic fungus Trichoderma taxi, on T. mentagrophytes was examined, and the underlying mechanism was explored. T. mentagrophytes growth was suppressed significantly by trichodermin and completely inhibited under 1000 µg/mL trichodermin. The production and germination of T. mentagrophytes spores were remarkably reduced upon exposure to trichodermin, in comparison with control samples. Treatment of lesions caused by T. mentagrophytes on the rabbit skin with 1 mg/mL trichodermin prompted the healing process significantly; however, 20 mg/mL trichodermin was likely toxic to the skin. Under trichodermin treatment, the number of mitochondria in T. mentagrophytes increased significantly, while a few mitochondria-related genes decreased, indicating possible mitochondrial damage. In transcriptome analysis, the GO terms enriched by DEGs in the trichodermin-treated group included carbohydrate metabolic process, integral component of membrane, intrinsic component of membrane, and carbohydrate binding, while the enriched KEGG pathways comprised biosynthesis of secondary metabolites, glycolysis/gluconeogenesis, and carbon metabolism. By comparing the wild type and a gene deletion strain of T. mentagrophytes, we found that CDR1, an ABC transporter encoding gene, was involved in T. mentagrophytes sensitivity to trichodermin.

20.
Front Microbiol ; 13: 962500, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36147853

RESUMO

Peroxisomes have been proved playing roles in infection of several plant pathogens. Although the contribution of a portion of peroxins in pathogenicity was demonstrated, most of them are undocumented in fungi, especially, Botrytis cinerea. The homologs of Pex8, Pex10, and Pex12 in B. cinerea were functionally characterized in this work using gene disruption strategies. Compared with the wild-type strain (WT), the Δbcpex8, Δbcpex10, and Δbcpex12 mutants exhibited significant reduction in melanin production, fatty acid utilization, and decreased tolerance to high osmotic pressure and reactive oxygen species (ROS). The mycelial growth and conidiation of were significantly inhibited in Δbcpex8, Δbcpex10, and Δbcpex12 strains. The mycelial growth rates of Δbcpex8, Δbcpex10, and Δbcpex12 were reduced by 32, 35, and 34%, respectively, compared with WT and ectopic transformant (ET), and the conidiation was reduced by approximately 89, 27, and 88%, respectively. The conidial germination, germ tube elongation, and the formation of initiate infection structures (IFSs) were also reduced by the deletion of the genes. The pathogenicity was tested on the leaves of tobacco and strawberry, and fruits of tomato. On the leaves of tobacco and strawberry, the Δbcpex8, Δbcpex10, and Δbcpex12 mutants could not induce necrotic lesions, and the lesions on tomato fruits infected with the mutants were significantly reduced than those of the wide type. The results indicated that BcPEX8, BcPEX10, and BcPEX12 are indispensable for the development and pathogenicity of B. cinerea.

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