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1.
Int J Mol Sci ; 23(3)2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35163113

RESUMO

Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is one of the most destructive foliar diseases of wheat. In this study, we combined the bulked segregant RNA sequencing (BSR-seq) and comparative genomics analysis to localize the powdery mildew resistance gene in Chinese landrace Xiaomaomai. Genetic analysis of F1 plants from a crossing of Xiaomaomai × Lumai23 and the derived F2 population suggests that a single recessive gene, designated as pmXMM, confers the resistance in this germplasm. A genetic linkage map was constructed using the newly developed SNP markers and pmXMM was mapped to the distal end of chromosome 2AL. The two flanking markers 2AL15 and 2AL34 were closely linked to pmXMM at the genetic distance of 3.9 cM and 1.4 cM, respectively. Using the diagnostic primers of Pm4, we confirmed that Xiaomaomai carries a Pm4 allele and the gene function was further validated by the virus-induced gene silencing (VIGS). In addition, we systematically analyzed pmXMM in comparison with the other Pm4 alleles. The results suggest that pmXMM is identical to Pm4d and Pm4e at sequence level. Pm4b is also not different from Pm4c according to their genome/amino acid sequences. Only a few nucleotide variances were detected between pmXMM and Pm4a/b, which indicate the haplotype variation of the Pm4 gene.


Assuntos
Ascomicetos/fisiologia , Cromossomos de Plantas/genética , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/genética , Proteínas de Plantas/genética , Triticum/genética , Mapeamento Cromossômico , Resistência à Doença/imunologia , Ligação Genética , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Triticum/imunologia , Triticum/microbiologia
2.
PLoS One ; 17(2): e0264027, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35171951

RESUMO

All stage resistance to stripe rust races prevalent in India was investigated in the European winter wheat cultivar 'Acienda'. In order to dissect the genetic basis of the resistance, a backcross population was developed between 'Acienda' and the stripe rust susceptible Indian spring wheat cultivar 'HD 2967'. Inheritance studies revealed segregation for a dominant resistant gene. High density SNP genotyping was used to map stripe rust resistance and marker regression analysis located stripe rust resistance to the distal end of wheat chromosome 1A. Interval mapping located this region between the SNP markers AX-95162217 and AX-94540853, at a LOD score of 15.83 with a phenotypic contribution of 60%. This major stripe rust resistance locus from 'Acienda' has been temporarily designated as Yraci. A candidate gene search in the 2.76 Mb region carrying Yraci on chromosome 1A identified 18 NBS-LRR genes based on wheat RefSeqv1.0 annotations. Our results indicate that as there is no major gene reported in the Yraci chromosome region, it is likely to be a novel stripe rust resistance locus and offers potential for deployment, using the identified markers, to confer all stage stripe rust resistance.


Assuntos
Basidiomycota/fisiologia , Resistência à Doença/genética , Doenças das Plantas/genética , Proteínas de Plantas/genética , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Triticum/genética , Mapeamento Cromossômico , Cromossomos de Plantas , Resistência à Doença/imunologia , Regulação da Expressão Gênica de Plantas , Índia , Padrões de Herança , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Estações do Ano , Triticum/crescimento & desenvolvimento , Triticum/imunologia
3.
Sci Rep ; 12(1): 15, 2022 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-34996967

RESUMO

The nutritional integrity of wheat is jeopardized by rapidly rising atmospheric carbon dioxide (CO2) and the associated emergence and enhanced virulence of plant pathogens. To evaluate how disease resistance traits may impact wheat climate resilience, 15 wheat cultivars with varying levels of resistance to Fusarium Head Blight (FHB) were grown at ambient and elevated CO2. Although all wheat cultivars had increased yield when grown at elevated CO2, the nutritional contents of FHB moderately resistant (MR) cultivars were impacted more than susceptible cultivars. At elevated CO2, the MR cultivars had more significant differences in plant growth, grain protein, starch, fructan, and macro and micro-nutrient content compared with susceptible wheat. Furthermore, changes in protein, starch, phosphorus, and magnesium content were correlated with the cultivar FHB resistance rating, with more FHB resistant cultivars having greater changes in nutrient content. This is the first report of a correlation between the degree of plant pathogen resistance and grain nutritional content loss in response to elevated CO2. Our results demonstrate the importance of identifying wheat cultivars that can maintain nutritional integrity and FHB resistance in future atmospheric CO2 conditions.


Assuntos
Dióxido de Carbono/metabolismo , Ecossistema , Fusarium/fisiologia , Doenças das Plantas/microbiologia , Triticum/química , Triticum/imunologia , Resistência à Doença , Magnésio/análise , Magnésio/metabolismo , Valor Nutritivo , Fósforo/análise , Fósforo/metabolismo , Doenças das Plantas/imunologia , Proteínas de Plantas/análise , Proteínas de Plantas/metabolismo , Sementes/química , Sementes/classificação , Sementes/imunologia , Sementes/metabolismo , Triticum/classificação , Triticum/metabolismo
4.
Theor Appl Genet ; 135(1): 301-319, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34837509

RESUMO

KEY MESSAGE: Analysis of a wheat multi-founder population identified 14 yellow rust resistance QTL. For three of the four most significant QTL, haplotype analysis indicated resistance alleles were rare in European wheat. Stripe rust, or yellow rust (YR), is a major fungal disease of wheat (Triticum aestivum) caused by Puccinia striiformis Westend f. sp. tritici (Pst). Since 2011, the historically clonal European Pst races have been superseded by the rapid incursion of genetically diverse lineages, reducing the resistance of varieties previously showing durable resistance. Identification of sources of genetic resistance to such races is a high priority for wheat breeding. Here we use a wheat eight-founder multi-parent population genotyped with a 90,000 feature single nucleotide polymorphism array to genetically map YR resistance to such new Pst races. Genetic analysis of five field trials at three UK sites identified 14 quantitative trait loci (QTL) conferring resistance. Of these, four highly significant loci were consistently identified across all test environments, located on chromosomes 1A (QYr.niab-1A.1), 2A (QYr.niab-2A.1), 2B (QYr.niab-2B.1) and 2D (QYr.niab-2D.1), together explaining ~ 50% of the phenotypic variation. Analysis of these four QTL in two-way and three-way combinations showed combinations conferred greater resistance than single QTL, and genetic markers were developed that distinguished resistant and susceptible alleles. Haplotype analysis in a collection of wheat varieties found that the haplotypes associated with YR resistance at three of these four major loci were rare (≤ 7%) in European wheat, highlighting their potential utility for future targeted improvement of disease resistance. Notably, the physical interval for QTL QYr.niab-2B.1 contained five nucleotide-binding leucine-rich repeat candidate genes with integrated BED domains, of which two corresponded to the cloned resistance genes Yr7 and Yr5/YrSp.


Assuntos
Resistência à Doença/genética , Doenças das Plantas/microbiologia , Puccinia/fisiologia , Triticum/genética , Genótipo , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Polimorfismo de Nucleotídeo Único , Puccinia/imunologia , Locos de Características Quantitativas , Triticum/imunologia , Triticum/microbiologia
5.
Theor Appl Genet ; 135(1): 351-365, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34665265

RESUMO

KEY MESSAGE: YrFDC12 and PbcFDC, co-segregated in chromosome 4BL, and significantly interacted with Yr30/Pbc1 to enhance stripe rust resistance and to promote pseudo-black chaff development. Cultivars with durable resistance are the most popular means to control wheat stripe rust. Durable resistance can be achieved by stacking multiple adult plant resistance (APR) genes that individually have relatively small effect. Chinese wheat cultivars Ruihua 520 (RH520) and Fengdecun 12 (FDC12) confer partial APR to stripe rust across environments. One hundred and seventy recombinant inbred lines from the cross RH520 × FDC12 were used to determine the genetic basis of resistance and identify genomic regions associated with stripe rust resistance. Genotyping was carried out using 55 K SNP array, and eight quantitative trait loci (QTL) were detected on chromosome arms 2AL, 2DS, 3BS, 4BL, 5BL (2), and 7BL (2) by inclusive composite interval mapping. Only QYr.nwafu-3BS from RH520 and QYr.nwafu-4BL.2 (named YrFDC12 for convenience) from FDC12 were consistent across the four testing environments. QYr.nwafu-3BS is likely the pleiotropic resistance gene Sr2/Yr30. YrFDC12 was mapped in a 2.1-cM interval corresponding to 12 Mb and flanked by SNP markers AX-111121224 and AX-89518393. Lines harboring both Yr30 and YrFDC12 displayed higher resistance than the parents and expressed pseudo-black chaff (PBC) controlled by loci Pbc1 and PbcFDC12, which co-segregated with Yr30 and YrFDC12, respectively. Both marker-based and pedigree-based kinship analyses revealed that YrFDC12 was inherited from founder parent Zhou 8425B. Fifty-four other wheat cultivars shared the YrFDC12 haplotype. These results suggest an effective pyramiding strategy to acquire highly effective, durable stripe rust resistance in breeding.


Assuntos
Cromossomos de Plantas , Resistência à Doença/genética , Genes de Plantas , Doenças das Plantas/genética , Puccinia/fisiologia , Triticum/genética , Mapeamento Cromossômico , Técnicas de Genotipagem , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Puccinia/imunologia , Locos de Características Quantitativas , Triticum/imunologia , Triticum/microbiologia
6.
Plant Physiol ; 187(4): 2530-2543, 2021 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-34890460

RESUMO

Several effectors from phytopathogens usually target various cell organelles to interfere with plant defenses, and they generally contain sequences that direct their translocation into organelles, such as chloroplasts. In this study, we characterized a different mechanism for effectors to attack chloroplasts in wheat (Triticum aestivum). Two effectors from Puccinia striiformis f. sp. tritici (Pst), Pst_4, and Pst_5, inhibit Bax-mediated cell death and plant immune responses, such as callose deposition and reactive oxygen species (ROS) accumulation. Gene silencing of the two effectors induced significant resistance to Pst, demonstrating that both effectors function as virulence factors of Pst. Although these two effectors have low sequence similarities and lack chloroplast transit peptides, they both interact with TaISP (wheat cytochrome b6-f complex iron-sulfur subunit, a chloroplast protein encoded by nuclear gene) in the cytoplasm. Silencing of TaISP impaired wheat resistance to avirulent Pst and resulted in less accumulation of ROS. Heterogeneous expression of TaISP enhanced chloroplast-derived ROS accumulation in Nicotiana benthamiana. Co-localization in N. benthamiana and western blot assay of TaISP content in wheat chloroplasts show that both effectors suppressed TaISP from entering chloroplasts. We conclude that these biotrophic fungal effectors suppress plant defenses by disrupting the sorting of chloroplast protein, thereby limiting host ROS accumulation and promoting fungal pathogenicity.


Assuntos
Basidiomycota/fisiologia , Cloroplastos/metabolismo , Doenças das Plantas/microbiologia , Imunidade Vegetal , Proteínas de Plantas/metabolismo , Triticum/imunologia , Transporte Biológico , Resistência à Doença , Triticum/microbiologia
7.
Nutrients ; 13(12)2021 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-34960101

RESUMO

Celiac disease (CD) is a genetically predisposed, T cell-mediated and autoimmune-like disorder caused by dietary exposure to the storage proteins of wheat and related cereals. A gluten-free diet (GFD) is the only treatment available for CD. The celiac immune response mediated by CD4+ T-cells can be assessed with a short-term oral gluten challenge. This study aimed to determine whether the consumption of bread made using flour from a low-gluten RNAi wheat line (named E82) can activate the immune response in DQ2.5-positive patients with CD after a blind crossover challenge. The experimental protocol included assessing IFN-γ production by peripheral blood mononuclear cells (PBMCs), evaluating gastrointestinal symptoms, and measuring gluten immunogenic peptides (GIP) in stool samples. The response of PBMCs was not significant to gliadin and the 33-mer peptide after E82 bread consumption. In contrast, PBMCs reacted significantly to Standard bread. This lack of immune response is correlated with the fact that, after E82 bread consumption, stool samples from patients with CD showed very low levels of GIP, and the symptoms were comparable to those of the GFD. This pilot study provides evidence that bread from RNAi E82 flour does not elicit an immune response after a short-term oral challenge and could help manage GFD in patients with CD.


Assuntos
Pão , Doença Celíaca/imunologia , Dieta Livre de Glúten , Gliadina/genética , Gliadina/imunologia , Glutens/imunologia , Interferência de RNA , Triticum/genética , Triticum/imunologia , Adulto , Doença Celíaca/genética , Feminino , Humanos , Leucócitos Mononucleares/imunologia , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Interferência de RNA/imunologia , Triticum/química , Adulto Jovem
8.
Int J Mol Sci ; 22(22)2021 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-34830231

RESUMO

Food insecurity and malnutrition have reached critical levels with increased human population, climate fluctuations, water shortage; therefore, higher-yielding crops are in the spotlight of numerous studies. Abiotic factors affect the yield of staple food crops; among all, wheat stem sawfly (Cephus cinctus Norton) and orange wheat blossom midge (Sitodiplosis mosellana) are two of the most economically and agronomically harmful insect pests which cause yield loss in cereals, especially in wheat in North America. There is no effective strategy for suppressing this pest damage yet, and only the plants with intrinsic tolerance mechanisms such as solid stem phenotypes for WSS and antixenosis and/or antibiosis mechanisms for OWBM can limit damage. A major QTL and a causal gene for WSS resistance were previously identified in wheat, and 3 major QTLs and a causal gene for OWBM resistance. Here, we present a comparative analysis of coding and non-coding features of these loci of wheat across important cereal crops, barley, rye, oat, and rice. This research paves the way for our cloning and editing of additional WSS and OWBM tolerance gene(s), proteins, and metabolites.


Assuntos
Dípteros/patogenicidade , Resistência à Doença/genética , Genoma de Planta , Himenópteros/patogenicidade , Doenças das Plantas/genética , Locos de Características Quantitativas , Triticum/genética , Animais , Avena/genética , Avena/imunologia , Avena/parasitologia , Mapeamento Cromossômico/métodos , Dípteros/fisiologia , Grão Comestível , Código Genético , Hordeum/genética , Hordeum/imunologia , Hordeum/parasitologia , Humanos , Himenópteros/fisiologia , Oryza/genética , Oryza/imunologia , Oryza/parasitologia , Doenças das Plantas/imunologia , Doenças das Plantas/parasitologia , Característica Quantitativa Herdável , Secale/genética , Secale/imunologia , Secale/parasitologia , Especificidade da Espécie , Triticum/imunologia , Triticum/parasitologia
9.
Int J Mol Sci ; 22(21)2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34768928

RESUMO

The Hessian fly is a destructive pest of wheat. Employing additional molecular strategies can complement wheat's native insect resistance. However, this requires functional characterization of Hessian-fly-responsive genes, which is challenging because of wheat genome complexity. The diploid Brachypodium distachyon (Bd) exhibits nonhost resistance to Hessian fly and displays phenotypic/molecular responses intermediate between resistant and susceptible host wheat, offering a surrogate genome for gene characterization. Here, we compared the transcriptomes of Biotype L larvae residing on resistant/susceptible wheat, and nonhost Bd plants. Larvae from susceptible wheat and nonhost Bd plants revealed similar molecular responses that were distinct from avirulent larval responses on resistant wheat. Secreted salivary gland proteins were strongly up-regulated in all larvae. Genes from various biological pathways and molecular processes were up-regulated in larvae from both susceptible wheat and nonhost Bd plants. However, Bd larval expression levels were intermediate between larvae from susceptible and resistant wheat. Most genes were down-regulated or unchanged in avirulent larvae, correlating with their inability to establish feeding sites and dying within 4-5 days after egg-hatch. Decreased gene expression in Bd larvae, compared to ones on susceptible wheat, potentially led to developmentally delayed 2nd-instars, followed by eventually succumbing to nonhost resistance defense mechanisms.


Assuntos
Brachypodium/imunologia , Resistência à Doença/genética , Nematóceros/genética , Triticum/imunologia , Animais , Perfilação da Expressão Gênica , Genoma/genética , Larva/genética , Nematóceros/embriologia , RNA-Seq , Transcriptoma/genética , Virulência/genética
10.
Int J Mol Sci ; 22(19)2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34638559

RESUMO

Although peroxisomes play an essential role in viral pathogenesis, and viruses are known to change peroxisome morphology, the role of genotype in the peroxisomal response to viruses remains poorly understood. Here, we analyzed the impact of wheat streak mosaic virus (WSMV) on the peroxisome proliferation in the context of pathogen response, redox homeostasis, and yield in two wheat cultivars, Patras and Pamir, in the field trials. We observed greater virus content and yield losses in Pamir than in Patras. Leaf chlorophyll and protein content measured at the beginning of flowering were also more sensitive to WSMV infection in Pamir. Patras responded to the WSMV infection by transcriptional up-regulation of the peroxisome fission genes PEROXIN 11C (PEX11C), DYNAMIN RELATED PROTEIN 5B (DRP5B), and FISSION1A (FIS1A), greater peroxisome abundance, and activation of pathogenesis-related proteins chitinase, and ß-1,3-glucanase. Oppositely, in Pamir, WMSV infection suppressed transcription of peroxisome biogenesis genes and activity of chitinase and ß-1,3-glucanase, and did not affect peroxisome abundance. Activity of ROS scavenging enzymes was higher in Patras than in Pamir. Thus, the impact of WMSV on peroxisome proliferation is genotype-specific and peroxisome abundance can be used as a proxy for the magnitude of plant immune response.


Assuntos
Resistência à Doença/imunologia , Peroxissomos/metabolismo , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Potyviridae , Triticum/imunologia , Triticum/virologia , Quitinases/metabolismo , Clorofila/metabolismo , Glucana 1,3-beta-Glucosidase/metabolismo , Oxirredução , Peroxidases/metabolismo , Peroxissomos/genética , Peroxissomos/virologia , Fenótipo , Folhas de Planta/imunologia , Folhas de Planta/virologia , Espécies Reativas de Oxigênio/metabolismo
11.
Plant J ; 108(5): 1241-1255, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34583419

RESUMO

Plants sense various pathogens and activate immunity responses through receptor-like kinases (RLKs). Cysteine-rich receptor-like kinases (CRKs) are involved in massive transduction pathways upon perception of a pathogen. However, the roles of CRKs in response to stripe rust are unclear. In the present study, we identified a CRK gene (designated TaCRK10) from wheat variety Xiaoyan 6 (XY6) that harbors high-temperature seedling-plant (HTSP) resistance to stripe rust caused by fungal pathogen Puccinia striiformis f. sp. tritici (Pst). The expression level of TaCRK10 was induced by Pst inoculation and high temperature treatment. Knockdown of TaCRK10 by virus-induced gene silencing resulted in attenuated wheat HTSP resistance to Pst, whereas there is no effect on Pst development and host responses under normal temperatures. Notably, overexpression of TaCRK10 in susceptible variety Fielder provided resistance only under normal temperatures at 14 days with reactive oxygen species accumulation and defense-related gene expression of the salicylic acid pathway. Moreover, TaCRK10 physically interacted with and phosphorylated a histone variant TaH2A.1, which belongs to the H2A.W group. Silencing of TaH2A.1 suppressed wheat resistance to Pst, indicating that TaH2A.1 plays a positive role in wheat resistance to Pst. Thus, TaCRK10 serves as an important sensor of Pst infection and high temperatures, and it activates wheat resistance to Pst through regulating nuclear processes. This knowledge helps elucidate the molecular mechanism of wheat HTSP resistance to Pst and promotes efforts in developing wheat varieties with resistance to stripe rust.


Assuntos
Resistência à Doença/genética , Interações Hospedeiro-Patógeno , Doenças das Plantas/imunologia , Proteínas de Plantas/metabolismo , Puccinia/fisiologia , Triticum/genética , Histonas/metabolismo , Temperatura Alta , Fosforilação , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Espécies Reativas de Oxigênio/metabolismo , Ácido Salicílico/metabolismo , Plântula/genética , Plântula/imunologia , Plântula/microbiologia , Plântula/fisiologia , Triticum/imunologia , Triticum/microbiologia , Triticum/fisiologia
12.
Sci Rep ; 11(1): 18876, 2021 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-34556726

RESUMO

Dwarf bunt caused by the pathogen Tilletia controversa Kühn is one of the most serious quarantine diseases of winter wheat. Metabolomics studies provide detailed information about the biochemical changes at the cell and tissue levels of plants. In the present study, a liquid chromatography/mass spectrometry (LC/MS) metabolomics approach was used to investigate the changes in the grain metabolomics of infected and noninfected with T. controversa samples. PCA suggested that T. controversa-infected and noninfected samples were separated during the interaction. LC/MS analysis showed that 62 different metabolites were recorded in the grains, among which a total of 34 metabolites were upregulated and 28 metabolites were downregulated. Prostaglandins (PGs) and 9-hydroxyoctadecadienoic acids (9-HODEs) are fungal toxin-related substances, and their expression significantly increased in T. controversa-infected grains. Additionally, the concentrations of cucurbic acid and octadecatrienoic acid changed significantly after pathogen infection, which play a large role in plant defense. The eight different metabolic pathways activated during T. controversa and wheat plant interactions included phenylalanine metabolism, isoquinoline alkaloid biosynthesis, starch and sucrose metabolism, tyrosine metabolism, sphingolipid metabolism, arginine and proline metabolism, alanine, aspartate, and glutamate metabolism, and tryptophan metabolism. In conclusion, we found differences in the metabolic profiles of wheat grains after T. controversa infection. To our knowledge, this is the first study to evaluate the metabolites in wheat grains after T. controversa infection.


Assuntos
Basidiomycota/imunologia , Doenças das Plantas/microbiologia , Triticum/imunologia , Resistência à Doença , Redes e Vias Metabólicas/imunologia , Metabolômica , Sementes/metabolismo , Sementes/microbiologia , Triticum/metabolismo , Triticum/microbiologia
13.
Curr Issues Mol Biol ; 43(2): 965-977, 2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34449534

RESUMO

Bread wheat is an essential crop with the second-highest global production after maize. Currently, wheat diseases are a serious threat to wheat production. Therefore, efficient breeding for disease resistance is extremely urgent in modern wheat. Here, we identified 2012 NLR genes from hexaploid wheat, and Ks values of paired syntenic NLRs showed a significant peak at 3.1-6.3 MYA, which exactly coincided with the first hybridization event between A and B genome lineages at ~5.5 MYA. We provided a landscape of dynamic diversity of NLRs from Triticum and Aegilops and found that NLR genes have higher diversity in wild progenitors and relatives. Further, most NLRs had opposite diversity patterns between genic and 2 Kb-promoter regions, which might respectively link sub/neofunctionalization and loss of duplicated NLR genes. Additionally, we identified an alien introgression of chromosome 4A in tetraploid emmer wheat, which was similar to that in hexaploid wheat. Transcriptome data from four experiments of wheat disease resistance helped to profile the expression pattern of NLR genes and identified promising NLRs involved in broad-spectrum disease resistance. Our study provided insights into the diversity evolution of NLR genes and identified beneficial NLRs to deploy into modern wheat in future wheat disease-resistance breeding.


Assuntos
Resistência à Doença/genética , Proteínas NLR/metabolismo , Doenças das Plantas/imunologia , Proteínas de Plantas/metabolismo , Triticum/genética , Resistência à Doença/imunologia , Genoma de Planta , Proteínas NLR/genética , Melhoramento Vegetal/métodos , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Transcriptoma , Triticum/imunologia , Triticum/metabolismo
14.
BMC Plant Biol ; 21(1): 393, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34418972

RESUMO

BACKGROUND: Mycotoxins are among the environmental stressors whose oxidative action is currently widely studied. The aim of this paper was to investigate the response of seedling leaves to zearalenone (ZEA) applied to the leaves (directly) and to the grains (indirectly) in tolerant and sensitive wheat cultivars. RESULTS: Biochemical analyses of antioxidant activity were performed for chloroplasts and showed a similar decrease in this activity irrespective of plant sensitivity and the way of ZEA application. On the other hand, higher amounts of superoxide radical (microscopic observations) were generated in the leaves of plants grown from the grains incubated in ZEA solution and in the sensitive cultivar. Electron paramagnetic resonance (EPR) studies showed that upon ZEA treatment greater numbers of Mn - aqua complexes were formed in the leaves of the tolerant wheat cultivar than in those of the sensitive one, whereas the degradation of Fe-protein complexes occurred independently of the cultivar sensitivity. CONCLUSION: The changes in the quantity of stable, organic radicals formed by stabilizing reactive oxygen species on biochemical macromolecules, indicated greater potential for their generation in leaf tissues subjected to foliar ZEA treatment. This suggested an important role of these radical species in protective mechanisms mainly against direct toxin action. The way the defense mechanisms were activated depended on the method of the toxin application.


Assuntos
Imunidade Vegetal/genética , Folhas de Planta/imunologia , Sementes/imunologia , Triticum/genética , Triticum/imunologia , Zearalenona/efeitos adversos , Grão Comestível/genética , Grão Comestível/imunologia , Espectroscopia de Ressonância de Spin Eletrônica , Variação Genética , Genótipo , Imunidade Vegetal/fisiologia , Folhas de Planta/genética , Plântula/genética , Plântula/imunologia , Sementes/genética
15.
Int J Mol Sci ; 22(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34445571

RESUMO

Photosynthesis is a universal process for plant survival, and immune defense is also a key process in adapting to the growth environment. Various studies have indicated that these two processes are interconnected in a complex network. Photosynthesis can influence signaling pathways and provide both materials and energy for immune defense, while the immune defense process can also have feedback effects on photosynthesis. Pathogen infection inevitably leads to changes in photosynthesis parameters, including Pn, Gs, and Ci; biochemical materials such as SOD and CAT; signaling molecules such as H2O2 and hormones; and the expression of genes involved in photosynthesis. Some researchers have found that changes in photosynthesis activity are related to the resistance level of the host, the duration after infection, and the infection position (photosynthetic source or sink). Interactions between wheat and the main fungal pathogens, such as Puccinia striiformis, Blumeria graminis, and Fusarium graminearum, constitute an ideal study system to elucidate the relationship between changes in host photosynthesis and resistance levels, based on the accessibility of methods for artificially controlling infection and detecting changes in photosynthesis, the presence of multiple pathogens infecting different positions, and the abundance of host materials with various resistance levels. This review is written only from the perspective of plant pathologists, and after providing an overview of the available data, we generally found that changes in photosynthesis in the early stage of pathogen infection could be a causal factor influencing acquired resistance, while those in the late stage could be the result of resistance formation.


Assuntos
Ascomicetos/fisiologia , Interações Hospedeiro-Patógeno , Fotossíntese , Doenças das Plantas/imunologia , Triticum/imunologia , Doenças das Plantas/microbiologia , Triticum/metabolismo , Triticum/microbiologia
16.
Mol Plant Microbe Interact ; 34(10): 1094-1102, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34096764

RESUMO

Plant-pathogen interactions result in disease development in a susceptible host. Plants actively resist pathogens via a complex immune system comprising both surface-localized receptors that sense the extracellular space as well as intracellular receptors recognizing pathogen effectors. To date, the majority of cloned resistance genes encode intracellular nucleotide-binding leucine-rich repeat receptor proteins. Recent discoveries have revealed tandem kinase proteins (TKPs) as another important family of intracellular proteins involved in plant immune responses. Five TKP genes-barley Rpg1 and wheat WTK1 (Yr15), WTK2 (Sr60), WTK3 (Pm24), and WTK4-protect against devastating fungal diseases. Moreover, a large diversity and numerous putative TKPs exist across the plant kingdom. This review explores our current knowledge of TKPs and serves as a basis for future studies that aim to develop and exploit a deeper understanding of innate plant immunity receptor proteins.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Resistência à Doença , Hordeum , Imunidade Vegetal , Proteínas Quinases , Triticum , Hordeum/enzimologia , Hordeum/imunologia , Doenças das Plantas , Proteínas Quinases/genética , Triticum/enzimologia , Triticum/imunologia
17.
Int J Mol Sci ; 22(9)2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-34067160

RESUMO

Puccinia striiformis f. sp. tritici (Pst) is an important pathogen of wheat (Triticum aestivum L.) stripe rust, and the effector protein secreted by haustoria is a very important component involved in the pathogenic process. Although the candidate effector proteins secreted by Pst haustoria have been predicted to be abundant, few have been functionally validated. Our study confirmed that chitin and flg22 could be used as elicitors of the pathogenic-associated molecular pattern-triggered immune (PTI) reaction in wheat leaves and that TaPr-1-14 could be used as a marker gene to detect the PTI reaction. In addition, the experimental results were consistent in wheat protoplasts. A rapid and efficient method for screening and identifying the effector proteins of Pst was established by using the wheat protoplast transient expression system. Thirty-nine Pst haustorial effector genes were successfully cloned and screened for expression in the protoplast. We identified three haustorial effector proteins, PSEC2, PSEC17, and PSEC45, that may inhibit the response of wheat to PTI. These proteins are localized in the somatic cytoplasm and nucleus of wheat protoplasts and are highly expressed during the infection and parasitism of wheat.


Assuntos
Proteínas Fúngicas/metabolismo , Imunidade , Padrões Moleculares Associados a Patógenos/metabolismo , Protoplastos/microbiologia , Puccinia/fisiologia , Triticum/imunologia , Triticum/microbiologia , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Quitina/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Imunidade/efeitos dos fármacos , Doenças das Plantas/microbiologia , Imunidade Vegetal/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Folhas de Planta/imunologia , Folhas de Planta/microbiologia , Protoplastos/efeitos dos fármacos , Puccinia/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Reprodutibilidade dos Testes , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo , Transcrição Genética/efeitos dos fármacos , Triticum/efeitos dos fármacos , Triticum/genética
18.
Mol Plant ; 14(7): 1088-1103, 2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-33798746

RESUMO

Virus-derived small interference RNAs (vsiRNAs) not only suppress virus infection in plants via induction of RNA silencing but also enhance virus infection by regulating host defensive gene expression. However, the underlying mechanisms that control vsiRNA-mediated host immunity or susceptibility remain largely unknown. In this study, we generated several transgenic wheat lines using four artificial microRNA expression vectors carrying vsiRNAs from Wheat yellow mosaic virus (WYMV) RNA1. Laboratory and field tests showed that two transgenic wheat lines expressing amiRNA1 were highly resistant to WYMV infection. Further analyses showed that vsiRNA1 could modulate the expression of a wheat thioredoxin-like gene (TaAAED1), which encodes a negative regulator of reactive oxygen species (ROS) production in the chloroplast. The function of TaAAED1 in ROS scavenging could be suppressed by vsiRNA1 in a dose-dependent manner. Furthermore, transgenic expression of amiRNA1 in wheat resulted in broad-spectrum disease resistance to Chinese wheat mosaic virus, Barley stripe mosaic virus, and Puccinia striiformis f. sp. tritici infection, suggesting that vsiRNA1 is involved in wheat immunity via ROS signaling. Collectively, these findings reveal a previously unidentified mechanism underlying the arms race between viruses and plants.


Assuntos
Vírus do Mosaico/genética , Doenças das Plantas/imunologia , RNA Interferente Pequeno/metabolismo , RNA Viral/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Triticum/imunologia , Sequestradores de Radicais Livres , Vetores Genéticos , Doenças das Plantas/virologia , Plantas Geneticamente Modificadas , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/isolamento & purificação , RNA Viral/genética , RNA Viral/isolamento & purificação , Tiorredoxinas/genética , Tabaco/genética , Tabaco/virologia , Triticum/genética , Triticum/metabolismo
19.
Int J Mol Sci ; 22(6)2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33803699

RESUMO

Leaf rust and powdery mildew are two important foliar diseases in wheat. A recombinant inbred line (RIL) population, obtained by crossing two bread wheat cultivars ('Victo' and 'Spada'), was evaluated for resistance to the two pathogens at seedling stage. Upon developing a genetic map of 8726 SNP loci, linkage analysis identified three resistance Quantitative Trait Loci (QTLs), with 'Victo' contributing the resistant alleles to all loci. One major QTL (QPm.gb-7A) was detected in response to Blumeria graminis on chromosome 7A, which explained 90% of phenotypic variation (PV). The co-positional relationship with known powdery mildew (Pm) resistance loci suggested that a new source of resistance was identified in T. aestivum. Two QTLs were detected in response to Puccinia triticina: a major gene on chromosome 5D (QLr.gb-5D), explaining a total PV of about 59%, and a minor QTL on chromosome 2B (QLr.gb-2B). A positional relationship was observed between the QLr.gb-5D with the known Lr1 gene, but polymorphisms were found between the cloned Lr1 and the corresponding 'Victo' allele, suggesting that QLr.gb-5D could represent a new functional Lr1 allele. Lastly, upon anchoring the QTL on the T. aestivum reference genome, candidate genes were hypothesized on the basis of gene annotation and in silico gene expression analysis.


Assuntos
Ascomicetos/fisiologia , Resistência à Doença/imunologia , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , Triticum/imunologia , Triticum/microbiologia , Sequência de Aminoácidos , Ascomicetos/isolamento & purificação , Pão , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Simulação por Computador , Cruzamentos Genéticos , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Marcadores Genéticos , Fenótipo , Proteínas de Plantas/química , Proteínas de Plantas/genética , Puccinia/isolamento & purificação , Locos de Características Quantitativas/genética
20.
Mol Plant Pathol ; 22(6): 683-693, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33797163

RESUMO

Chitin is a major structural component of fungal cell walls and acts as a microbe-associated molecular pattern (MAMP) that, on recognition by a plant host, triggers the activation of immune responses. To avoid the activation of these responses, the Septoria tritici blotch (STB) pathogen of wheat, Zymoseptoria tritici, secretes LysM effector proteins. Previously, the LysM effectors Mg1LysM and Mg3LysM were shown to protect fungal hyphae against host chitinases. Furthermore, Mg3LysM, but not Mg1LysM, was shown to suppress chitin-induced reactive oxygen species (ROS) production. Whereas initially a third LysM effector gene was disregarded as a presumed pseudogene, we now provide functional data to show that this gene also encodes a LysM effector, named Mgx1LysM, that is functional during wheat colonization. While Mg3LysM confers a major contribution to Z. tritici virulence, Mgx1LysM and Mg1LysM contribute to Z. tritici virulence with smaller effects. All three LysM effectors display partial functional redundancy. We furthermore demonstrate that Mgx1LysM binds chitin, suppresses the chitin-induced ROS burst, and is able to protect fungal hyphae against chitinase hydrolysis. Finally, we demonstrate that Mgx1LysM is able to undergo chitin-induced polymerization. Collectively, our data show that Z. tritici utilizes three LysM effectors to disarm chitin-triggered wheat immunity.


Assuntos
Ascomicetos/fisiologia , Quitina/metabolismo , Proteínas Fúngicas/metabolismo , Doenças das Plantas/microbiologia , Imunidade Vegetal , Triticum/microbiologia , Proteínas Fúngicas/genética , Interações Hospedeiro-Patógeno , Doenças das Plantas/imunologia , Triticum/imunologia , Virulência
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