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1.
Front Microbiol ; 15: 1422476, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38933037

RESUMO

Rice blast, a prevalent and highly destructive rice disease that significantly impacts rice yield, is caused by the rice blast fungus. In the present study, a strain named MTC-8, identified as Bacillus mojavensis, was demonstrated has strong antagonistic activity against the rice blast fungus, Rhizoctonia solani, Ustilaginoidea virens, and Bipolaria maydis. The potential biocontrol agents were identified using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis and chromatography. Further investigations elucidated the inhibitory mechanism of the isolated compound and demonstrated its ability to suppress spore germination, alter hyphal morphology, disrupt cell membrane integrity, and induce defense-related gene expression in rice. MTC-8 promoted plant growth and may lead to the development of a biocontrol agent that meets agricultural standards. Overall, the Bacillus mojavensis MTC-8 strain exerted beneficial effects on plant growth, immunity and disease resistance against rice blast fungus. In this study, we isolated and purified a bioactive substance from fermentation broth, and the results provide a foundation for the development and application of biopesticides. Elucidation of the inhibitory mechanism against rice blast fungus provides theoretical support for the identification of molecular targets. The successful development of a biocontrol agent lays the groundwork for its practical application in agriculture.

2.
Front Microbiol ; 15: 1298781, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38650873

RESUMO

Fungal diseases such as the devastating rice blast pose severe threats to crop production worldwide. Biological control of crop diseases caused by fungal pathogens is an environment-friendly approach for safeguarding crop production. But the insufficient availability of microbial agents effective against various fungal diseases has hampered the development of green production in crops. In this study, we identified a broad-spectrum antifungal bacterium, Streptomyces graminearus STR-1, showing antagonistic activity to diverse fungal pathogens including Magnaporthe oryzae, Rhizoctonia solani, Fusarium graminearum, Ustilaginoidea virens, and Bipolaris maydis. Its antifungal activity was relatively stable and less affected by temperature and pH. Evaluation of the biocontrol activity of STR-1 revealed that STR-1 prevented and controlled rice blast disease via eliciting plant immunity and suppressing fungal infection-structure development. STR-1 broth extract inhibited spore germination, likely through inhibiting protein synthesis. Combining LC-MS and chromatography analysis of the antimicrobial compounds purified from STR-1 broth extract, together with decoding STR-1 genomic sequence, we identified 4-oxo-4-[(1-phenylethyl)amino]but-2-enoic acid, 1,3,5-Trimethylpyrazole and SMA-1 as the potential main STR-1 secondary metabolites associated with its antifungal effects. This study suggests that bacterial strain STR-1 could be used for identifying highly effective and broad-spectrum secondary metabolites for containing rice blast and other crop diseases. The application of the active compounds offers a promising measure to tackle fungal disease.

3.
J Hazard Mater ; 465: 133079, 2024 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-38029593

RESUMO

Celosia argentea is a manganese (Mn) hyperaccumulator with high ornamental value and strong stress resistance. It is important to understand the molecular mechanism of tolerance to heavy metals of hyperaccumulators to improve the efficiency of phytoremediation. In this study, the effects of different Mn concentrations (0, 0.8, 3, and 10 mM) on physiological characteristics and molecular changes were determined. Low concentrations of Mn increased the growth of C. argentea, while high concentrations of Mn suppressed its growth, A concentration up to 3 mM did not affect the growth of C. argentea, and the highest transfer factor (TF) was 6.16. Oxidative damage of different Mn level treatments in C. argentea was verified through relative water content, electrolyte leakage, MDA content, H2O2 content and superoxide contents. With an increase in Mn concentration, the contents of chlorophyll a, chlorophyll b, and carotenoids decreased. Our results indicated that low-concentration manganese treatment can reduce the reactive oxygen burst and MDA, soluble sugar and proline, making C. argentea have strong abiotic stress tolerance. The molecular mechanism of C. argentea after 10 mM Mn treatment was analysed through transcriptome analysis, and differentially expressed genes (DEGs) in these pathways were further verified by qRTPCR. Plantpathogen interactions, plant hormone signal transduction, the MAPK signalling pathway and the phenylpropanoid biosynthesis pathway were important in the response to Mn stress, and the heavy metal-associated isoprenylated plant protein, metal transporter Nramp, and zinc transporter play key roles in the strong ability of C. argentea to tolerate heavy metals. These results suggest that C. argentea exhibits strong manganese tolerance and provide new insight into the molecular mechanisms of plant responses to heavy metal stress.


Assuntos
Celosia , Metais Pesados , Manganês/metabolismo , Clorofila A , Peróxido de Hidrogênio/metabolismo , Metais Pesados/metabolismo , Celosia/metabolismo , Perfilação da Expressão Gênica
4.
Nat Commun ; 14(1): 8399, 2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-38110425

RESUMO

Fungal pathogens typically use secreted effector proteins to suppress host immune activators to facilitate invasion. However, there is rarely evidence supporting the idea that fungal secretory proteins contribute to pathogenesis by transactivating host genes that suppress defense. We previously found that pathogen Magnaporthe oryzae induces rice Bsr-d1 to facilitate infection and hypothesized that a fungal effector mediates this induction. Here, we report that MoSPAB1 secreted by M. oryzae directly binds to the Bsr-d1 promoter to induce its expression, facilitating pathogenesis. Amino acids 103-123 of MoSPAB1 are required for its binding to the Bsr-d1 promoter. Both MoSPAB1 and rice MYBS1 compete for binding to the Bsr-d1 promoter to regulate Bsr-d1 expression. Furthermore, MoSPAB1 homologues are highly conserved among fungi. In particular, Colletotrichum fructicola CfSPAB1 and Colletotrichum sublineola CsSPAB1 activate kiwifruit AcBsr-d1 and sorghum SbBsr-d1 respectively, to facilitate pathogenesis. Taken together, our findings reveal a conserved module that may be widely utilized by fungi to enhance pathogenesis.


Assuntos
Ascomicetos , Magnaporthe , Oryza , Oryza/genética , Magnaporthe/genética , Ascomicetos/metabolismo , Transporte Biológico , Doenças das Plantas/microbiologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo
5.
Foods ; 12(14)2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37509820

RESUMO

Despite the popularity of wild edible mushrooms due to their delectable flavor and nutritional value, the mechanisms involved in regulating and altering their taste remain underexplored. In this study, we analyzed the metabolome and transcriptome of Boletus brunneissimus (B. brunneissimus) and Leccinum extremiorientale (L. extremiorientale), two Boletus species collected from different environments. Using UHPLC-MS, we annotated 644 peaks and identified 47 differential metabolites via OPLS-DA analysis. Eight of these were related to flavor, including L-Aspartic acid, Glycine, D-Serine, L-Serine, L-Histidine, Tryptophan, L-Isoleucine, Isoleucine, and alpha-D-Glucose. These differential metabolites were mainly concentrated in amino acid metabolism pathways. Transcriptome analysis revealed differential genes between B. brunneissimus and L. extremiorientale, which were enriched in protein processing in the endoplasmic reticulum, as well as differential genes of the same Boletus species in different environments that were enriched in the ribosome pathway. The combination of metabolome and transcriptome analyses highlighted Glycine, L-Serine, and L-Aspartic acid as the key compounds responsible for the differences between the two Boletus species. Using the O2PLS model and Pearson's coefficient, we identified key genes that modulate the differences in metabolites between the two species. These results have significant implications for the molecular breeding of flavor in edible mushrooms.

6.
Front Plant Sci ; 14: 1097044, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36938063

RESUMO

Introduction: Plant pathogens are one of the major constraints on worldwide food production. The antibiotic properties of microbes identified as effective in managing plant pathogens are well documented. Methods: Here, we used antagonism experiments and untargeted metabolomics to isolate the potentially antifungal molecules produced by KJ-34. Results: KJ-34 is a potential biocontrol bacterium isolated from the rhizosphere soil of rice and can fight multiple fungal pathogens (i.e. Ustilaginoidea virens, Alternaria solani, Fusarium oxysporum, Phytophthora capsica, Corynespora cassiicola). The favoured fermentation conditions are determined and the fermentation broth treatment can significantly inhibit the infection of Magnaporthe oryzae and Botryis cinerea. The fermentation broth suppression ratio is 75% and 82%, respectively. Fermentation broth treatment disrupted the spore germination and led to malformation of hyphae. Additionally, we found that the molecular weight of antifungal products were less than 1000 Da through semipermeable membranes on solid medium assay. To search the potentially antifungal molecules that produce by KJ-34, we used comparative and bioinformatics analyses of fermentation broth before and after optimization by mass spectrometry. Untargeted metabolomics analyses are presumed to have a library of antifungal agents including benzoylstaurosporine, morellin and scopolamine. Discussion: These results suggest that KJ-34 produced various biological control agents to suppress multiple phytopathogenic fungi and showed a strong potential in the ecological technologies of prevention and protection.

7.
Plant Commun ; 4(3): 100505, 2023 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-36527233

RESUMO

Here we describe a novel narnavirus, Puccinia striiformis virus 5 (PsV5), from the devastating wheat stripe rust fungus P. striiformis f. sp. tritici (Pst). The genome of PsV5 contains two predicted open reading frames (ORFs) that largely overlap on reverse strands: an RNA-dependent RNA polymerase (RdRp) and a reverse-frame ORF (rORF) with unknown function. Protein translations of both ORFs were demonstrated by immune technology. Transgenic wheat lines overexpressing PsV5 (RdRp-rORF), RdRp ORF, or rORF were more susceptible to Pst infection, whereas PsV5-RNA interference (RNAi) lines were more resistant. Overexpression of PsV5 (RdRp-rORF), RdRp ORF, or rORF in Fusarium graminearum also boosted fungal virulence. We thus report a novel ambigrammatic mycovirus that promotes the virulence of its fungal host. The results are a significant addition to our understanding of virosphere diversity and offer insights for sustainable wheat rust disease control.


Assuntos
Basidiomycota , Micovírus , Micovírus/genética , Triticum/microbiologia , Basidiomycota/genética , Puccinia
8.
Nat Microbiol ; 5(12): 1565-1575, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32958858

RESUMO

Many pathogenic fungi depend on the development of specialized infection structures called appressoria to invade their hosts and cause disease. Impairing the function of fungal infection structures therefore provides a potential means by which diseases could be prevented. In spite of this extraordinary potential, however, relatively few anti-penetrant drugs have been developed to control fungal diseases, of either plants or animals. In the present study, we report the identification of compounds that act specifically to prevent fungal infection. We found that the organization of septin GTPases, which are essential for appressorium-mediated infection in the rice blast fungus Magnaporthe oryzae, requires very-long-chain fatty acids (VLCFAs), which act as mediators of septin organization at membrane interfaces. VLCFAs promote septin recruitment to curved plasma membranes and depletion of VLCFAs prevents septin assembly and host penetration by M. oryzae. We observed that VLCFA biosynthesis inhibitors not only prevent rice blast disease, but also show effective, broad-spectrum fungicidal activity against a wide range of fungal pathogens of maize, wheat and locusts, without affecting their respective hosts. Our findings reveal a mechanism underlying septin-mediated infection structure formation in fungi and provide a class of fungicides to control diverse diseases of plants and animals.


Assuntos
Inibidores Enzimáticos/farmacologia , Proteínas Fúngicas/antagonistas & inibidores , Fungos/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Doenças das Plantas/microbiologia , Septinas/antagonistas & inibidores , Ascomicetos/efeitos dos fármacos , Ascomicetos/enzimologia , Ascomicetos/genética , Ácidos Graxos/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fungos/enzimologia , Fungos/genética , Oryza/microbiologia , Septinas/genética , Septinas/metabolismo
9.
Mol Plant Pathol ; 21(7): 951-960, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32394633

RESUMO

bsr-d1, an allele encoding a transcription factor identified from the rice cultivar Digu, confers durable, broad-spectrum resistance to infections by strains of Magnaporthe oryzae. bsr-d1 was predicted to inhibit M. oryzae-induced expression of Bsr-d1 RNA and degradation of hydrogen peroxide to achieve resistance to M. oryzae. However, the global effect of biological process and molecular function on blast resistance mediated by Bsr-d1 remains unknown. In this study, we compared transcriptomic profiling between Bsr-d1 knockout (Bsr-d1KO) lines and the wild type, TP309. Our study revealed that bsr-d1 mainly regulates the redox state of plant cells, but also affects amino acid and unsaturated fatty acid metabolism. We further found that BSR-D1 indirectly regulates salicylic acid biosynthesis, metabolism, and signal transduction downstream of the activation of H2 O2 signalling in the bsr-d1-mediated immune response. Furthermore, we identified a novel peroxidase-encoding gene, Perox3, as a new BSR-D1 target gene that reduces resistance to M. oryzae when overexpressed in TP309. These results provide new insights into the bsr-d1-mediated blast resistance.


Assuntos
Ascomicetos , Oryza/microbiologia , Doenças das Plantas/microbiologia , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Resistência à Doença/genética , Resistência à Doença/imunologia , Perfilação da Expressão Gênica , Técnicas de Inativação de Genes , Oryza/enzimologia , Oryza/genética , Oryza/imunologia , Peroxidase/genética , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Proteínas de Plantas/genética , Fatores de Transcrição/genética
10.
New Phytol ; 226(6): 1850-1863, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32112568

RESUMO

Broad-spectrum resistance is highly preferred in crop breeding programmes. Previously, we have reported the identification of the broad-spectrum resistance-Digu 1 (bsr-d1) allele from rice Digu. The bsr-d1 allele prevents activation of Bsr-d1 expression by Magnaporthe oryzae infection and degradation of H2 O2 by peroxidases, leading to resistance to M. oryzae. However, it remains unknown whether defence pathways other than H2 O2 burst and peroxidases contribute to the bsr-d1-mediated immunity. Blast resistance was determined in rice leaves by spray and punch inoculations. Target genes of OsMYB30 were identified by one-hybrid assays in yeast and electrophoretic mobility shift assay. Lignin content was measured by phloroglucinol-HCl staining, and acetyl bromide and thioacidolysis methods. Here, we report the involvement of the OsMYB30 gene in bsr-d1-mediated blast resistance. Expression of OsMYB30 was induced during M. oryzae infection or when Bsr-d1 was knocked out or downregulated, as occurs in bsr-d1 plants upon infection. We further found that OsMYB30 bound to and activated the promoters of 4-coumarate:coenzyme A ligase genes (Os4CL3 and Os4CL5) resulting in accumulation of lignin subunits G and S. This action led to obvious thickening of sclerenchyma cells near the epidermis, inhibiting M. oryzae penetration at the early stage of infection. Our study revealed novel components required for bsr-d1-mediated resistance and penetration-dependent immunity, and advanced our understanding of broad-spectrum disease resistance.


Assuntos
Magnaporthe , Oryza , Ascomicetos , Resistência à Doença/genética , Oryza/genética , Melhoramento Vegetal , Doenças das Plantas , Folhas de Planta
11.
Front Plant Sci ; 10: 1362, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31737001

RESUMO

Fusarium head blight (FHB) caused by Fusarium pathogens are devastating diseases worldwide. Host-induced gene silencing (HIGS) which involves host expression of double-stranded RNA (dsRNA)-generating constructs directed against genes in the pathogen has been a potential strategy for the ecological sound control of FHB. In this study, we constructed transgenic Brachypodium distachyon lines carrying RNA interference (RNAi) cassettes to target two essential protein kinase genes Fg00677 and Fg08731, and cytochrome P450 lanosterol C14-α-demethylase (CYP51) encoding genes (CYP51A, CYP51B, and CYP51C) of Fusarium graminearum, respectively. Northern blotting confirmed the presence of short interfering RNAs (siRNA) derived from Fg00677, Fg08731, and CYP51 in transgenic B. distachyon plants, and the transcript levels of the corresponding genes were down-regulated in the F. graminearum colonizing B. distachyon spikes. All the corresponding independent, Fg00677-RNAi, Fg08731-RNAi, and CYP51-RNAi transgenic T2 lines exhibited strong resistance to F. graminearum, suggesting that silencing molecules produced by transgenic plants inhibited the corresponding gene function by down-regulating its expression, thereby reducing pathogenicity. Our results indicate that Fg00677 and Fg08731 are effective targets for HIGS and can be applied to construct transgenic HIGS materials to enhance FHB resistance in wheat and other cereal crops.

12.
Mol Plant ; 12(12): 1624-1638, 2019 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-31606466

RESUMO

Puccinia striiformis f. sp. tritici (Pst), a biotrophic plant pathogen, secretes numerous effectors to modulate host defense systems. Understanding the molecular mechanisms by which Pst effectors regulate wheat immunity is of great importance for the development of novel strategies for durable control of stripe rust. In this study, we identified a glycine-serine-rich effector gene, PstGSRE1, which is highly induced during early infection. Transgenic expression of PstGSRE1 RNAi constructs in wheat significantly reduced virulence of Pst and increased H2O2 accumulation in wheat. PstGSRE1 was shown to target the reactive oxygen species (ROS)-associated transcription factor TaLOL2, a positive regulator of wheat immunity. PstGSRE1 disrupted nuclear localization of TaLOL2 and suppressed ROS-mediated cell death induced by TaLOL2, thus compromising host immunity. This work reveals a previously unrecognized strategy whereby rust fungi exploit the PstGSRE1 effector to defeat ROS-associated plant defense by modulating the subcellular compartment of a host immune regulator and facilitate pathogen infection.


Assuntos
Basidiomycota/fisiologia , Núcleo Celular/metabolismo , Doenças das Plantas/microbiologia , Proteínas de Plantas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fatores de Transcrição/metabolismo , Triticum/microbiologia , Transporte Ativo do Núcleo Celular , Basidiomycota/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Inativação Gênica , Triticum/citologia , Triticum/metabolismo , Triticum/fisiologia
13.
Int J Mol Sci ; 20(1)2019 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-30626050

RESUMO

Wheat and barley are the most highly produced and consumed grains in the world. Various pathogens-viruses, bacteria, fungi, insect pests, and nematode parasites-are major threats to yield and economic losses. Strategies for the management of disease control mainly depend on resistance or tolerance breeding, chemical control, and biological control. The discoveries of RNA silencing mechanisms provide a transgenic approach for disease management. Host-induced gene silencing (HIGS) employing RNA silencing mechanisms and, specifically, silencing the targets of invading pathogens, has been successfully applied in crop disease prevention. Here, we cover recent studies that indicate that HIGS is a valuable tool to protect wheat and barley from diseases in an environmentally friendly way.


Assuntos
Inativação Gênica , Hordeum/genética , Interações Hospedeiro-Patógeno/genética , Doenças das Plantas/genética , Doenças das Plantas/prevenção & controle , Triticum/genética
14.
Arch Virol ; 164(3): 897-901, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30600350

RESUMO

The complete genome of a novel mycovirus, Puccinia striiformis mitovirus 1 (PsMV1), derived from the wheat stripe rust fungus Puccinia striiformis strain SCSN-10, was sequenced and analyzed. The full-length cDNA sequence is 2496 bp in length with a predicted AU content of 57.65% in the genomic RNA. Sequence analysis indicated that a single large open reading frame (ORF) is present on the positive strand when the fungal mitochondrial genetic code is used. The single ORF encodes a putative RNA-dependent RNA polymerase of 743 amino acids with a molecular mass of 84.9 kDa that shares the closest similarity with the corresponding proteins of Cronartium ribicola mitovirus 5 and Helicobasidium mompa mitovirus 1-18 (34% and 35% aa sequence identity, respectively). Phylogenetic analysis further indicated that PsMV1 is a new member of the genus Mitovirus within the family Narnaviridae. This is the first report of the full-length nucleotide sequence of a novel mitovirus, PsMV1, from the causal agent of wheat stripe rust.


Assuntos
Basidiomycota/virologia , Micovírus/genética , Genoma Viral , Doenças das Plantas/microbiologia , Vírus de RNA/genética , Triticum/microbiologia , Sequência de Bases , Basidiomycota/fisiologia , Micovírus/classificação , Micovírus/isolamento & purificação , Dados de Sequência Molecular , Fases de Leitura Aberta , Filogenia , Vírus de RNA/classificação , Vírus de RNA/isolamento & purificação
15.
Plant Biotechnol J ; 17(5): 956-968, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30451367

RESUMO

Calcineurin B-like interacting protein kinase (CIPKs) has been shown to be required for biotic stress tolerance of plants in plant-pathogen interactions. However, the roles of CIPKs in immune signalling of cereal crops and an in-depth knowledge of substrates of CIPKs in response to biotic stress are under debate. In this study, we identified and cloned a CIPK homologue gene TaCIPK10 from wheat. TaCIPK10 was rapidly induced by Puccinia striiformis f. sp. tritici (Pst) inoculation and salicylic acid (SA) treatment. In vitro phosphorylation assay demonstrated that the kinase activity of TaCIPK10 is regulated by Ca2+ and TaCBL4. Knockdown TaCIPK10 significantly reduced wheat resistance to Pst, whereas TaCIPK10 overexpression resulted in enhanced wheat resistance to Pst by the induction of defense response in different aspects, including hypersensitive cell death, ROS accumulation and pathogenesis-relative genes expression. Moreover, TaCIPK10 physically interacted with and phosphorylated TaNH2, which was homologous to AtNPR3/4. Silencing of TaNH2 in wheat resulted in enhanced susceptibility to the avirulent Pst race, CYR23, indicating its positive role in wheat resistance. Our results demonstrate that TaCIPK10 positively regulate wheat resistance to Pst as molecular links between of Ca2+ and downstream components of defense response and TaCIPK10 interacts with and phosphorylates TaNH2 to regulate wheat resistance to Pst.


Assuntos
Basidiomycota , Resistência à Doença , Imunidade Vegetal , Proteínas de Plantas/fisiologia , Triticum/microbiologia , Cálcio/metabolismo , Técnicas de Silenciamento de Genes , Fosforilação , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Triticum/genética , Triticum/imunologia
17.
J Exp Bot ; 69(18): 4443-4457, 2018 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-29931351

RESUMO

Calcineurin B-like proteins (CBLs) act as Ca2+ sensors to activate specific protein kinases, namely CBL-interacting protein kinases (CIPKs). Recent research has demonstrated that the CBL-CIPK complex is not only required for abiotic stress signaling, but is also probably involved in biotic stress perception. However, the role of this complex in immune signaling, including pathogen perception, is unknown. In this study, we isolated one signaling component of the TaCBL-TaCIPK complex (TaCBL4-TaCIPK5) and characterized its role in the interaction between wheat (Triticum aestivum) and Puccinia striiformis f. sp. tritici (Pst, stripe rust fungus). Among all TaCBLs in wheat, TaCBL4 mRNA accumulation markedly increased after infection by Pst. Silencing of TaCBL4 resulted in enhanced susceptibility to avirulent Pst infection. In addition, screening determined that TaCIPK5 physically interacted with TaCBL4 in planta and positively contributed to wheat resistance to Pst. Moreover, the disease resistance phenotype of TaCBL4 and TaCIPK5 co-silenced plants was consistent with that of single-knockdown plants. The accumulation of reactive oxygen species (ROS) was significantly altered in all silenced plants during Pst infection. Together these findings demonstrate that the TaCBL4-TaCIPK5 complex positively modulates wheat resistance in a ROS-dependent manner, and provide new insights into the roles of CBL-CIPK in wheat.


Assuntos
Basidiomycota/fisiologia , Resistência à Doença/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Triticum/genética , Cálcio/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Triticum/metabolismo , Triticum/microbiologia
18.
Plant Biotechnol J ; 16(3): 797-807, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28881438

RESUMO

Rust fungi are devastating plant pathogens and cause a large economic impact on wheat production worldwide. To overcome this rapid loss of resistance in varieties, we generated stable transgenic wheat plants expressing short interfering RNAs (siRNAs) targeting potentially vital genes of Puccinia striiformis f. sp. tritici (Pst). Protein kinase A (PKA) has been proved to play important roles in regulating the virulence of phytopathogenic fungi. PsCPK1, a PKA catalytic subunit gene from Pst, is highly induced at the early infection stage of Pst. The instantaneous silencing of PsCPK1 by barley stripe mosaic virus (BSMV)-mediated host-induced gene silencing (HIGS) results in a significant reduction in the length of infection hyphae and disease phenotype. These results indicate that PsCPK1 is an important pathogenicity factor by regulating Pst growth and development. Two transgenic lines expressing the RNA interference (RNAi) construct in a normally susceptible wheat cultivar displayed high levels of stable and consistent resistance to Pst throughout the T3 to T4 generations. The presence of the interfering RNAs in transgenic wheat plants was confirmed by northern blotting, and these RNAs were found to efficiently down-regulate PsCPK1 expression in wheat. This study addresses important aspects for the development of fungal-derived resistance through the expression of silencing constructs in host plants as a powerful strategy to control cereal rust diseases.


Assuntos
Basidiomycota/metabolismo , Basidiomycota/patogenicidade , Inativação Gênica/fisiologia , Triticum/microbiologia , Basidiomycota/genética , Proteínas Quinases Dependentes de AMP Cíclico/genética , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Interferência de RNA , Triticum/metabolismo , Virulência/genética , Virulência/fisiologia , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
19.
Plant Physiol ; 175(4): 1853-1863, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29070517

RESUMO

RNA interference (RNAi) is a powerful genetic tool to accelerate research in plant biotechnology and control biotic stresses by manipulating target gene expression. However, the potential of RNAi in wheat to efficiently and durably control the devastating stripe rust fungus Puccinia striiformis f. sp. tritici (Pst) remained largely under explored so far. To address this issue, we generated transgenic wheat (Triticum aestivum) lines expressing dsRNA targeting PsFUZ7 transcripts of Pst We analyzed expression of PsFUZ7 and related genes, and resistance traits of the transgenic wheat lines. We show that PsFUZ7 is an important pathogenicity factor that regulates infection and development of Pst A PsFUZ7 RNAi construct stably expressed in two independent transgenic wheat lines confers strong resistance to PstPst hyphal development is strongly restricted, and necrosis of plant cells in resistance responses was significantly induced. We conclude that trafficking of RNA molecules from wheat plants to Pst may lead to a complex molecular dialogue between wheat and the rust pathogen. Moreover, we confirm the RNAi-based crop protection approaches can be used, to our knowledge, as a novel control strategy against rust pathogens in wheat.


Assuntos
Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica/imunologia , Regulação da Expressão Gênica de Plantas/imunologia , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Triticum/microbiologia , Basidiomycota/fisiologia , Proteínas Fúngicas/genética , Doenças das Plantas/microbiologia , Interferência de RNA
20.
Front Plant Sci ; 8: 1245, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28769954

RESUMO

The actin cytoskeleton participates in numerous cellular processes, including less-characterized processes, such as nuclear organization, chromatin remodeling, transcription, and signal transduction. As a key regulator of actin cytoskeletal dynamics, the actin related protein 2/3 complex (Arp2/3 complex) controls multiple developmental processes in a variety of tissues and cell types. To date, the role of the Arp2/3 complex in plant disease resistance signaling is largely unknown. Herein, we identified and characterized wheat ARPC3, TaARPC3, which encodes the C3 subunit of the Arp2/3 complex. Expression of TaARPC3 in the arc18 mutant of Saccharomyces cerevisiae Δarc18 resulted in complementation of stress-induced phenotypes in S. cerevisiae, as well as restore wild-type cell shape malformations. TaARPC3 was found predominantly to be localized in the nucleus and cytoplasm when expressed transiently in wheat protoplast. TaARPC3 was significantly induced in response to avirulent race of Puccinia striiformis f. sp. tritici (Pst). Knock-down of TaARPC3 by virus-induced gene silencing resulted in a reduction of resistance against Pst through a specific reduction in actin cytoskeletal organization. Interestingly, this reduction was found to coincide with a block in reactive oxygen species (ROS) accumulation, the hypersensitive response (HR), an increase in TaCAT1 mRNA accumulation, and the growth of Pst. Taken together, these findings suggest that TaARPC3 is a key subunit of the Arp2/3 complex which is required for wheat resistance against Pst, a process that is associated with the regulation of the actin cytoskeleton.

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