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1.
Int J Mol Sci ; 22(15)2021 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-34361121

RESUMO

The first line of plant defence responses against pathogens can be induced by the bacterial flg22 and can be dependent on various external and internal factors. Here, we firstly studied the effects of daytime and ethylene (ET) using Never ripe (Nr) mutants in the local and systemic defence responses of intact tomato plants after flg22 treatments. Flg22 was applied in the afternoon and at night and rapid reactions were detected. The production of hydrogen peroxide and nitric oxide was induced by flg22 locally, while superoxide was induced systemically, in wild type plants in the light period, but all remained lower at night and in Nr leaves. Flg22 elevated, locally, the ET, jasmonic acid (JA) and salicylic acid (SA) levels in the light period; these levels did not change significantly at night. Expression of Pathogenesis-related 1 (PR1), Ethylene response factor 1 (ERF1) and Defensin (DEF) showed also daytime- and ET-dependent changes. Enhanced ERF1 and DEF expression and stomatal closure were also observable in systemic leaves of wild type plants in the light. These data demonstrate that early biotic signalling in flg22-treated leaves and distal ones is an ET-dependent process and it is also determined by the time of day and inhibited in the early night phase.


Assuntos
Ritmo Circadiano , Etilenos/farmacologia , Lycopersicon esculentum/imunologia , Doenças das Plantas/imunologia , Folhas de Planta/imunologia , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/efeitos dos fármacos , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Transdução de Sinais
2.
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
3.
Nat Microbiol ; 6(7): 852-864, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34194036

RESUMO

The plant microbiota consists of a multitude of microorganisms that can affect plant health and fitness. However, it is currently unclear how the plant shapes its leaf microbiota and what role the plant immune system plays in this process. Here, we evaluated Arabidopsis thaliana mutants with defects in different parts of the immune system for an altered bacterial community assembly using a gnotobiotic system. While higher-order mutants in receptors that recognize microbial features and in defence hormone signalling showed substantial microbial community alterations, the absence of the plant NADPH oxidase RBOHD caused the most pronounced change in the composition of the leaf microbiota. The rbohD knockout resulted in an enrichment of specific bacteria. Among these, we identified Xanthomonas strains as opportunistic pathogens that colonized wild-type plants asymptomatically but caused disease in rbohD knockout plants. Strain dropout experiments revealed that the lack of RBOHD unlocks the pathogenicity of individual microbiota members driving dysbiosis in rbohD knockout plants. For full protection, healthy plants require both a functional immune system and a microbial community. Our results show that the NADPH oxidase RBOHD is essential for microbiota homeostasis and emphasizes the importance of the plant immune system in controlling the leaf microbiota.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/microbiologia , Homeostase , Microbiota , NADPH Oxidases/metabolismo , Arabidopsis/enzimologia , Arabidopsis/imunologia , Proteínas de Arabidopsis/genética , Bactérias/classificação , Bactérias/crescimento & desenvolvimento , Bactérias/patogenicidade , Fenômenos Fisiológicos Bacterianos , Genótipo , NADPH Oxidases/genética , Fenótipo , Imunidade Vegetal/genética , Folhas de Planta/enzimologia , Folhas de Planta/imunologia , Folhas de Planta/microbiologia
4.
Int J Mol Sci ; 22(14)2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34299202

RESUMO

Rice spotted leaf mutants are helpful to investigate programmed cell death (PCD) and defense response pathways in plants. Using a map-based cloning strategy, we characterized novel rice spotted leaf mutation splHM143 that encodes a 7-hydroxymethyl chlorophyll a reductase (OsHCAR). The wild-type (WT) allele could rescue the mutant phenotype, as evidenced by complementation analysis. OsHCAR was constitutively expressed at all rice tissues tested and its expression products localized to chloroplasts. The mutant exhibited PCD and leaf senescence with increased H2O2 (hydrogen peroxide) accumulation, increased of ROS (reactive oxygen species) scavenging enzymes activities and TUNEL (terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling) -positive nuclei, upregulation of PCD related genes, decreased chlorophyll (Chl) contents, downregulation of photosynthesis-related genes, and upregulation of senescence-associated genes. Besides, the mutant exhibited enhanced bacterial blight resistance with significant upregulation of defense response genes. Knockout lines of OsHCAR exhibited spotted leaf phenotype, cell death, leaf senescence, and showed increased resistance to the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo) coupled with upregulation of five pathogenesis-related marker genes. The overexpression of OsHCAR resulted in increased susceptibility to Xoo with decreased expression of pathogenesis-related marker genes. Altogether, our findings revealed that OsHCAR is involved in regulating cell death and defense response against bacterial blight pathogen in rice.


Assuntos
Resistência à Doença/imunologia , Oryza/imunologia , Oxirredutases/metabolismo , Doenças das Plantas/imunologia , Folhas de Planta/imunologia , Proteínas de Plantas/metabolismo , Xanthomonas/fisiologia , Clorofila/análogos & derivados , Clorofila/metabolismo , Regulação da Expressão Gênica de Plantas , Oryza/enzimologia , Oryza/crescimento & desenvolvimento , Oxirredutases/genética , Doenças das Plantas/microbiologia , Folhas de Planta/enzimologia , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética
5.
Int J Mol Sci ; 22(11)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200345

RESUMO

Efficient accumulation of flavonoids is important for increased tolerance to biotic stress. Although several plant defense mechanisms are known, the roles of many pathways, proteins, and secondary metabolites in stress tolerance are unknown. We generated a flavanone 3-hydroxylase (F3H) overexpressor rice line and inoculated Xanthomonas Oryzae pv. oryzae and compared the control and wildtype inoculated plants. In addition to promoting plant growth and developmental maintenance, the overexpression of F3H increased the accumulation of flavonoids and increased tolerance to bacterial leaf blight (BLB) stress. Moreover, leaf lesion length was higher in the infected wildtype plants compared with infected transgenics. Kaempferol and quercetin, which scavenge reactive oxygen species, overaccumulated in transgenic lines compared with wildtypes in response to pathogenic infection, detected by scanning electron microscopy and spectrophotometry. The induction of F3H altered the antioxidant system and reduced the levels of glutathione peroxidase activity and malondialdehyde (MDA) contents in the transgenic lines compared with the wildtypes. Downstream gene regulation analysis showed that the expression of F3H increased the regulation of flavonol synthase (FLS), dihydroflavonol 4-reductase (DFR), and slender rice mutant (SLR1) during BLB stress. The analysis of SA and JA signaling revealed an antagonistic interaction between both hormones and that F3H induction significantly promoted SA and inhibited JA accumulation in the transgenic lines. SA-dependent nonexpressor pathogenesis-related (NPR1) and Xa1 showed significant upregulation in the infected transgenic lines compared with the infected control and wildtype lines. Thus, the overexpression of F3H was essential for increasing BLB stress tolerance.


Assuntos
Antioxidantes/metabolismo , Resistência à Doença/imunologia , Flavonoides/metabolismo , Hormônios/metabolismo , Oxigenases de Função Mista/metabolismo , Oryza/imunologia , Doenças das Plantas/imunologia , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Oxigenases de Função Mista/genética , Oryza/genética , Oryza/metabolismo , Oryza/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Folhas de Planta/imunologia , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/imunologia , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/microbiologia , Estresse Fisiológico , Xanthomonas/fisiologia
6.
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
7.
Nat Commun ; 12(1): 2739, 2021 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-34016974

RESUMO

In addition to conspicuous large mesophyll chloroplasts, where most photosynthesis occurs, small epidermal chloroplasts have also been observed in plant leaves. However, the functional significance of this small organelle remains unclear. Here, we present evidence that Arabidopsis epidermal chloroplasts control the entry of fungal pathogens. In entry trials, specialized fungal cells called appressoria triggered dynamic movement of epidermal chloroplasts. This movement is controlled by common regulators of mesophyll chloroplast photorelocation movement, designated as the epidermal chloroplast response (ECR). The ECR occurs when the PEN2 myrosinase-related higher-layer antifungal system becomes ineffective, and blockage of the distinct steps of the ECR commonly decreases preinvasive nonhost resistance against fungi. Furthermore, immune components were preferentially localized to epidermal chloroplasts, contributing to antifungal nonhost resistance in the pen2 background. Our findings reveal that atypical small chloroplasts act as defense-related motile organelles by specifically positioning immune components in the plant epidermis, which is the first site of contact between the plant and pathogens. Thus, this work deepens our understanding of the functions of epidermal chloroplasts.


Assuntos
Arabidopsis/imunologia , Cloroplastos/imunologia , Resistência à Doença/imunologia , Doenças das Plantas/imunologia , Epiderme Vegetal/imunologia , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Auxilinas/genética , Auxilinas/metabolismo , Proteínas de Cloroplastos/genética , Proteínas de Cloroplastos/metabolismo , Cloroplastos/metabolismo , Colletotrichum/imunologia , Colletotrichum/patogenicidade , Interações Hospedeiro-Patógeno/imunologia , Magnaporthe/imunologia , Magnaporthe/patogenicidade , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Mutação , N-Glicosil Hidrolases/genética , N-Glicosil Hidrolases/metabolismo , Doenças das Plantas/microbiologia , Epiderme Vegetal/citologia , Epiderme Vegetal/metabolismo , Epiderme Vegetal/microbiologia , Folhas de Planta/citologia , Folhas de Planta/imunologia , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Plantas Geneticamente Modificadas , Pseudomonas syringae/imunologia , Pseudomonas syringae/patogenicidade
8.
Nat Commun ; 12(1): 2451, 2021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33907187

RESUMO

Many pathogens infect hosts through specific organs, such as Ustilaginoidea virens, which infects rice panicles. Here, we show that a microbe-associated molecular pattern (MAMP), Ser-Thr-rich Glycosyl-phosphatidyl-inositol-anchored protein (SGP1) from U. virens, induces immune responses in rice leaves but not panicles. SGP1 is widely distributed among fungi and acts as a proteinaceous, thermostable elicitor of BAK1-dependent defense responses in N. benthamiana. Plants specifically recognize a 22 amino acid peptide (SGP1 N terminus peptide 22, SNP22) in its N-terminus that induces cell death, oxidative burst, and defense-related gene expression. Exposure to SNP22 enhances rice immunity signaling and resistance to infection by multiple fungal and bacterial pathogens. Interestingly, while SGP1 can activate immune responses in leaves, SGP1 is required for U. virens infection of rice panicles in vivo, showing it contributes to the virulence of a panicle adapted pathogen.


Assuntos
Proteínas Fúngicas/imunologia , Hypocreales/patogenicidade , Oryza/imunologia , Doenças das Plantas/imunologia , Folhas de Planta/imunologia , Proteínas de Plantas/imunologia , Sequência de Aminoácidos , Morte Celular/genética , Morte Celular/imunologia , Proteínas Fúngicas/genética , Regulação da Expressão Gênica , Glicosilfosfatidilinositóis/química , Glicosilfosfatidilinositóis/metabolismo , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Hypocreales/genética , Hypocreales/crescimento & desenvolvimento , Hypocreales/imunologia , Inflorescência/genética , Inflorescência/imunologia , Inflorescência/microbiologia , Oryza/genética , Oryza/microbiologia , Padrões Moleculares Associados a Patógenos/imunologia , Padrões Moleculares Associados a Patógenos/metabolismo , Peptídeos/genética , Peptídeos/imunologia , Células Vegetais/imunologia , Células Vegetais/patologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Imunidade Vegetal/genética , Folhas de Planta/genética , Folhas de Planta/microbiologia , Proteínas de Plantas/genética , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transdução de Sinais , Virulência
9.
Mol Plant Pathol ; 22(5): 495-507, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33709540

RESUMO

TAXONOMY: Phylum Nematoda; class Chromadorea; order Rhabditida; suborder Tylenchina; infraorder Tylenchomorpha; superfamily Tylenchoidea; family Heteroderidae; subfamily Heteroderinae; Genus Globodera. BIOLOGY: Potato cyst nematodes (PCN) are biotrophic, sedentary endoparasitic nematodes. Invasive (second) stage juveniles (J2) hatch from eggs in response to the presence of host root exudates and subsequently locate and invade the host. The nematodes induce the formation of a large, multinucleate syncytium in host roots, formed by fusion of up to 300 root cell protoplasts. The nematodes rely on this single syncytium for the nutrients required to develop through a further three moults to the adult male or female stage. This extended period of biotrophy-between 4 and 6 weeks in total-is almost unparalleled in plant-pathogen interactions. Females remain at the root while adult males revert to the vermiform body plan of the J2 and leave the root to locate and fertilize the female nematodes. The female body forms a cyst that contains the next generation of eggs. HOST RANGE: The host range of PCN is limited to plants of the Solanaceae family. While the most economically important hosts are potato (Solanum tuberosum), tomato (Solanum lycopersicum), and aubergine (Solanum melongena), over 170 species of Solanaceae are thought to be potential hosts for PCN (Sullivan et al., 2007). DISEASE SYMPTOMS: Symptoms are similar to those associated with nutrient deficiency, such as stunted growth, yellowing of leaves and reduced yields. This absence of specific symptoms reduces awareness of the disease among growers. DISEASE CONTROL: Resistance genes (where available in suitable cultivars), application of nematicides, crop rotation. Great effort is put into reducing the spread of PCN through quarantine measures and use of certified seed stocks. USEFUL WEBSITES: Genomic information for PCN is accessible through WormBase ParaSite.


Assuntos
Genoma Helmíntico/genética , Interações Hospedeiro-Parasita , Lycopersicon esculentum/parasitologia , Doenças das Plantas/parasitologia , Solanum tuberosum/parasitologia , Tylenchoidea/fisiologia , Animais , Resistência à Doença/genética , Feminino , Genômica , Especificidade de Hospedeiro/genética , Lycopersicon esculentum/genética , Lycopersicon esculentum/imunologia , Masculino , Doenças das Plantas/prevenção & controle , Folhas de Planta/genética , Folhas de Planta/imunologia , Folhas de Planta/parasitologia , Raízes de Plantas/genética , Raízes de Plantas/imunologia , Raízes de Plantas/parasitologia , Solanum tuberosum/genética , Solanum tuberosum/imunologia , Tylenchoidea/genética
10.
Plant Physiol ; 185(2): 424-440, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-33721890

RESUMO

Orobanche cumana is a holoparasitic plant that attaches to host-plant roots and seriously reduces the yield of sunflower (Helianthus annuus L.). Effective control methods are lacking with only a few known sources of genetic resistance. In this study, a seed-soak agroinoculation (SSA) method was established, and recombinant tobacco rattle virus vectors were constructed to express RNA interference (RNAi) inducers to cause virus-induced gene silencing (VIGS) in sunflower. A host target gene HaTubulin was systemically silenced in both leaf and root tissues by the SSA-VIGS approach. Trans-species silencing of O. cumana genes were confirmed for 10 out of 11 target genes with silencing efficiency of 23.43%-92.67%. Knockdown of target OcQR1, OcCKX5, and OcWRI1 genes reduced the haustoria number, and silencing of OcEXPA6 caused further phenotypic abnormalities such as shorter tubercles and necrosis. Overexpression of OcEXPA6 caused retarded root growth in alfalfa (Medicago sativa). The results demonstrate that these genes play an important role in the processes of O. cumana parasitism. High-throughput small RNA (sRNA) sequencing and bioinformatics analyses unveiled the distinct features of target gene-derived siRNAs in O. cumana such as siRNA transitivity, strand polarity, hotspot region, and 21/22-nt siRNA predominance, the latter of which was confirmed by Northern blot experiments. The possible RNAi mechanism is also discussed by analyzing RNAi machinery genes in O. cumana. Taken together, we established an efficient host-induced gene silencing technology for both functional genetics studies and potential control of O. cumana. The ease and effectiveness of this strategy could potentially be useful for other species provided they are amenable to SSA.


Assuntos
Resistência à Doença/genética , Helianthus/genética , Orobanche/fisiologia , Doenças das Plantas/imunologia , Proteínas de Plantas/genética , Biologia Computacional , Expressão Gênica , Inativação Gênica , Helianthus/imunologia , Sequenciamento de Nucleotídeos em Larga Escala , Medicago sativa/genética , Medicago sativa/crescimento & desenvolvimento , Necrose , Orobanche/genética , Folhas de Planta/genética , Folhas de Planta/imunologia , Raízes de Plantas/genética , Raízes de Plantas/imunologia , Vírus de Plantas/genética , Interferência de RNA , Sementes/genética , Sementes/imunologia , Análise de Sequência de RNA , Tubulina (Proteína)/genética
11.
Plant Sci ; 304: 110811, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33568308

RESUMO

Maize (Zea mays L.) production is severely affected by northern corn leaf blight (NCLB), which is a destructive foliar disease caused by Setosphaeria turcica. In recent years, studies on the interaction between maize and S. turcica have been focused at the transcription level, with no research yet at the protein level. Here, we applied tandem mass tag labelling and liquid chromatography-tandem mass spectrometry to investigate the proteomes of maize leaves at 24 h and 72 h post-inoculation (hpi) with S. turcica. In total, 4740 proteins encoded by 4711 genes were quantified in this study. Clustering analyses provided an understanding of the dynamic reprogramming of leaves proteomes by revealing the functions of different proteins during S. turcica infection. Screening and classification of differentially expressed proteins (DEPs) revealed that numerous defense-related proteins, including defense marker proteins and proteins related to the phenylpropanoid lignin biosynthesis, benzoxazine biosynthesis and the jasmonic acid signalling pathway, participated in the defense responses of maize to S. turcica infection. Furthermore, the earlier induction of GST family proteins contributed to the resistance to S. turcica. In addition, the protein-protein interaction network of DEPs suggests that some defense-related proteins, for example, ZmGEB1, a hub node, play key roles in defense responses against S. turcica infection. Our study findings provide insight into the complex responses triggered by S. turcica at the protein level and lay the foundation for studying the interaction process between maize and S. turcica infection.


Assuntos
Ascomicetos , Doenças das Plantas/microbiologia , Zea mays/microbiologia , Ciclopentanos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Glutationa Transferase/metabolismo , Redes e Vias Metabólicas , Oxilipinas/metabolismo , Doenças das Plantas/imunologia , Reguladores de Crescimento de Plantas/metabolismo , Folhas de Planta/imunologia , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Proteínas de Plantas/metabolismo , Mapas de Interação de Proteínas , Proteômica , Transcriptoma , Zea mays/imunologia , Zea mays/metabolismo
12.
Biomolecules ; 11(2)2021 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-33562549

RESUMO

Polyamines (PAs) are ubiquitous small aliphatic polycations important for growth, development, and environmental stress responses in plants. Here, we demonstrate that exogenous application of spermine (Spm) and spermidine (Spd) induced cell death at high concentrations, but primed resistance against the necrotrophic fungus Botrytis cinerea in Arabidopsis. At low concentrations, Spm was more effective than Spd. Treatments with higher exogenous Spd and Spm concentrations resulted in a biphasic endogenous PA accumulation. Exogenous Spm induced the accumulation of H2O2 after treatment but also after infection with B. cinerea. Both Spm and Spd induced the activities of catalase, ascorbate peroxidase, and guaiacol peroxidase after treatment but also after infection with B. cinerea. The soluble sugars glucose, fructose, and sucrose accumulated after treatment with high concentrations of PAs, whereas only Spm induced sugar accumulation after infection. Total and active nitrate reductase (NR) activities were inhibited by Spm treatment, whereas Spd inhibited active NR at low concentrations but promoted active NR at high concentrations. Finally, γaminobutyric acid accumulated after treatment and infection in plants treated with high concentrations of Spm. Phenylalanine and asparagine also accumulated after infection in plants treated with a high concentration of Spm. Our data illustrate that Spm and Spd are effective in priming resistance against B. cinerea, opening the door for the development of sustainable alternatives for chemical pesticides.


Assuntos
Antifúngicos/farmacologia , Arabidopsis/efeitos dos fármacos , Botrytis/patogenicidade , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Imunidade Vegetal/efeitos dos fármacos , Espermidina/farmacologia , Espermina/farmacologia , Arabidopsis/genética , Arabidopsis/imunologia , Arabidopsis/metabolismo , Ascorbato Peroxidases/genética , Ascorbato Peroxidases/imunologia , Asparagina/imunologia , Asparagina/metabolismo , Botrytis/imunologia , Catalase/genética , Catalase/imunologia , Resistência à Doença/efeitos dos fármacos , Resistência à Doença/genética , Frutose/imunologia , Frutose/metabolismo , Glucose/imunologia , Glucose/metabolismo , Peróxido de Hidrogênio , Nitrato Redutase/genética , Nitrato Redutase/imunologia , Peroxidase/genética , Peroxidase/imunologia , Fenilalanina/imunologia , Fenilalanina/metabolismo , Doenças das Plantas/imunologia , Doenças das Plantas/prevenção & controle , Reguladores de Crescimento de Plantas/farmacologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Folhas de Planta/imunologia , Folhas de Planta/metabolismo , Sacarose/imunologia , Sacarose/metabolismo , Ácido gama-Aminobutírico/imunologia , Ácido gama-Aminobutírico/metabolismo
13.
Plant J ; 106(2): 526-535, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33533097

RESUMO

Northern corn leaf blight, caused by the fungal pathogen Setosphaeria turcica (anamorph Exserohilum turcicum), is one of the most devastating foliar diseases of maize (Zea mays). Four genes Ht1, Ht2, Ht3 and Htn1 represent the major sources of genetic resistance against the hemibiotrophic fungus S. turcica. Differential maize lines containing these genes also form the basis to classify S. turcica races. Here, we show that Ht2 and Ht3 are identical and allelic to the previously cloned Htn1 gene. Using a map-based cloning approach and Targeting Induced Local Lesions in Genomes (TILLING), we demonstrate that Ht2/Ht3 is an allele of the wall-associated receptor-like kinase gene ZmWAK-RLK1. The ZmWAK-RLK1 variants encoded by Htn1 and Ht2/Ht3 differ by multiple amino acid polymorphisms that particularly affect the putative extracellular domain. A diversity analysis in maize revealed the presence of dozens of ZmWAK-RLK1 alleles. Ht2, Ht3 and Htn1 have been described over decades as independent resistance loci with different race spectra and resistance responses. Our work demonstrates that these three genes are allelic, which has major implications for northern corn leaf blight resistance breeding and nomenclature of S. turcica pathotypes. We hypothesize that genetic background effects have confounded the classical description of these disease resistance genes in the past.


Assuntos
Ascomicetos , Resistência à Doença/genética , Genes de Plantas/genética , Doenças das Plantas/imunologia , Folhas de Planta/imunologia , Zea mays/imunologia , Alelos , Ascomicetos/imunologia , Mapeamento Cromossômico , Fosfotransferases/genética , Fosfotransferases/fisiologia , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Folhas de Planta/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/fisiologia , Zea mays/genética , Zea mays/microbiologia
14.
Mol Plant Pathol ; 22(4): 410-421, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33486803

RESUMO

The constitutive photomorphogenesis 9 (COP9) signalosome (CSN) is a versatile regulator of plant growth, development, and response to diverse pathogens. However, little research has been done to understand the function of those CSN genes in broad-spectrum resistance to pathogens. In this study, we found that the transcript levels of wheat TaCSN5 were induced in response to inoculation with Puccinia striiformis f. sp. tritici (Pst) and treatment with salicylic acid (SA). Overexpression of TaCSN5 in Arabidopsis resulted in increased susceptibility to Pseudomonas syringae pv. tomato DC3000 infection accompanied by down-regulation of AtPR1 expression. Overexpression of TaCSN5 in wheat lines significantly increased susceptibility to Pst accompanied by decreased SA accumulation, whereas TaCSN5-RNAi wheat lines exhibited opposite trends. Moreover, we found that TaCSN5 negatively regulated TaG3NPR1 genes involved in the SA signalling pathway. In addition, TaCSN5-RNAi lines showed increased resistance to multiple races of Pst. Taken together, we demonstrate that TaCSN5 contributes to negative regulation of wheat resistance to Pst in an SA-dependent manner.


Assuntos
Arabidopsis/genética , Complexo do Signalossomo COP9/metabolismo , Doenças das Plantas/imunologia , Pseudomonas syringae/fisiologia , Puccinia/fisiologia , Triticum/genética , Antifúngicos/farmacologia , Arabidopsis/imunologia , Arabidopsis/microbiologia , Complexo do Signalossomo COP9/genética , Resistência à Doença/genética , Inativação Gênica , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Folhas de Planta/imunologia , Folhas de Planta/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Interferência de RNA , Ácido Salicílico/farmacologia , Transdução de Sinais , Triticum/imunologia , Triticum/microbiologia
15.
Mol Biol Rep ; 48(1): 731-742, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33389532

RESUMO

Rusts are a group of major diseases that have an adverse effect on crop production. Those targeting wheat are found in three principal forms: leaf, stripe, and stem rust. Leaf rust causes foliar disease in wheat; in Egypt, this causes a significant annual yield loss. The deployment of resistant genotypes has proved to be a relatively economical and environmentally sustainable method of controlling the disease. Gene pyramiding can be performed using traditional breeding techniques. Additionally, pathotypes can be introduced to examine specific leaf rust genes, or the breeder may conduct more complex breeding methods. Indirect selection via DNA markers linked to resistance genes may facilitate the transfer of targeted genes, either individually or in combination, even in a disease-free environment. The use of selective crosses to counter virulent races of leaf, stripe, and stem rust has resulted in the transfer of several resistance genes into new wheat germplasm from cultivated or wild species. Quantitative trait locus (QTL) technology has been adopted in a wide variety of novel approaches and is becoming increasingly recognized in wheat breeding. Moreover, several researchers have reported the transference of leaf and stripe rust resistance genes into susceptible wheat cultivars.


Assuntos
Basidiomycota/patogenicidade , Resistência à Doença/genética , Melhoramento Vegetal/métodos , Doenças das Plantas/genética , Folhas de Planta/genética , Triticum/genética , Basidiomycota/imunologia , Mapeamento Cromossômico , Cromossomos de Plantas/química , Cromossomos de Plantas/metabolismo , Ligação Genética , Marcadores Genéticos , Genótipo , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Folhas de Planta/classificação , Folhas de Planta/imunologia , Folhas de Planta/microbiologia , Locos de Características Quantitativas , Triticum/classificação , Triticum/imunologia , Triticum/microbiologia
16.
Mol Plant Pathol ; 22(3): 361-372, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33497519

RESUMO

Studies on plant-pathogen interactions often involve monitoring disease symptoms or responses of the host plant to pathogen-derived immunogenic patterns, either visually or by staining the plant tissue. Both these methods have limitations with respect to resolution, reproducibility, and the ability to quantify the results. In this study we show that red light detection by the red fluorescent protein (RFP) channel of a multipurpose fluorescence imaging system that is probably available in many laboratories can be used to visualize plant tissue undergoing cell death. Red light emission is the result of chlorophyll fluorescence on thylakoid membrane disassembly during the development of a programmed cell death process. The activation of programmed cell death can occur during either a hypersensitive response to a biotrophic pathogen or an apoptotic cell death triggered by a necrotrophic pathogen. Quantifying the intensity of the red light signal enables the magnitude of programmed cell death to be evaluated and provides a readout of the plant immune response in a faster, safer, and nondestructive manner when compared to previously developed chemical staining methodologies. This application can be implemented to screen for differences in symptom severity in plant-pathogen interactions, and to visualize and quantify in a more sensitive and objective manner the intensity of the plant response on perception of a given immunological pattern. We illustrate the utility and versatility of the method using diverse immunogenic patterns and pathogens.


Assuntos
Apoptose , Arabidopsis/fisiologia , Interações Hospedeiro-Patógeno , Lilium/fisiologia , Tabaco/fisiologia , Arabidopsis/citologia , Arabidopsis/imunologia , Arabidopsis/microbiologia , Luz , Lilium/genética , Lilium/imunologia , Lilium/microbiologia , Imagem Óptica , Folhas de Planta/imunologia , Folhas de Planta/microbiologia , Folhas de Planta/efeitos da radiação , Reprodutibilidade dos Testes , Tabaco/imunologia , Tabaco/microbiologia , Tabaco/efeitos da radiação
17.
PLoS One ; 16(1): e0245148, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33481834

RESUMO

The pathological interaction between oak trees and Phytophthora cinnamomi has implications in the cork oak decline observed over the last decades in the Iberian Peninsula. During host colonization, the phytopathogen secretes effector molecules like elicitins to increase disease effectiveness. The objective of this study was to unravel the proteome changes associated with the cork oak immune response triggered by P. cinnamomi inoculation in a long-term assay, through SWATH-MS quantitative proteomics performed in the oak leaves. Using the Arabidopis proteome database as a reference, 424 proteins were confidently quantified in cork oak leaves, of which 80 proteins showed a p-value below 0.05 or a fold-change greater than 2 or less than 0.5 in their levels between inoculated and control samples being considered as altered. The inoculation of cork oak roots with P. cinnamomi increased the levels of proteins associated with protein-DNA complex assembly, lipid oxidation, response to endoplasmic reticulum stress, and pyridine-containing compound metabolic process in the leaves. In opposition, several proteins associated with cellular metabolic compound salvage and monosaccharide catabolic process had significantly decreased abundances. The most significant abundance variations were observed for the Ribulose 1,5-Bisphosphate Carboxylase small subunit (RBCS1A), Heat Shock protein 90-1 (Hsp90-1), Lipoxygenase 2 (LOX2) and Histone superfamily protein H3.3 (A8MRLO/At4G40030) revealing a pertinent role for these proteins in the host-pathogen interaction mechanism. This work represents the first SWATH-MS analysis performed in cork oak plants inoculated with P. cinnamomi and highlights host proteins that have a relevant action in the homeostatic states that emerge from the interaction between the oomycete and the host in the long term and in a distal organ.


Assuntos
Phytophthora/imunologia , Doenças das Plantas , Proteínas de Plantas/imunologia , Raízes de Plantas , Quercus , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Folhas de Planta/imunologia , Folhas de Planta/microbiologia , Raízes de Plantas/imunologia , Raízes de Plantas/microbiologia , Proteômica , Quercus/imunologia , Quercus/microbiologia , Espanha
18.
Sci Rep ; 11(1): 628, 2021 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-33436688

RESUMO

This study was conducted to determine the root system architecture and biochemical responses of three potato (Solanum tuberosum L.) cultivars to drought and aphid (Myzus persicae Sulzer) infestation under greenhouse conditions. A factorial experiment comprising three potato cultivars (Qingshu 9, Longshu 3, and Atlantic), two levels of water (Well watered and drought) application and aphid infestation (Aphids and no aphids) was conducted. The results show that drought stress and aphid infestation significantly increased the root-projected area, root surface area, number of root tips, and number of root forks of all cultivars, relative to their corresponding control plants. The least root projected area, root surface area, number of root tips, and number of root forks occurred on DXY under both drought and aphid infestation. Nevertheless, the greatest root projected area, root surface area, number of root tips and number of root forks occurred on QS9 plants. Moreover, increased SOD, CAT, and POD activities were observed across all cultivars, under drought and aphid stress. The highest SOD, POD, and CAT activities occurred in QS9; under drought and aphid stress, while the least SOD, POD, and CAT activities was observed in DXY. The Atlantic cultivar, which possesses a root system sensitive to water deficit, demonstrated greater resistance to aphid infestation under well-watered and drought-stressed conditions. Conversely, Qingshu 9, which possesses a root system tolerant to water deficit, was highly susceptible to aphids. This study shows that the root architectural and biochemical traits that enhance potato tolerance to drought do not necessarily correlate to a plant's tolerance to aphids.


Assuntos
Antioxidantes/metabolismo , Afídeos/fisiologia , Secas , Regulação Enzimológica da Expressão Gênica , Folhas de Planta/imunologia , Solanum tuberosum/imunologia , Estresse Fisiológico , Animais , Folhas de Planta/parasitologia , Solanum tuberosum/enzimologia , Solanum tuberosum/parasitologia
19.
Plant Cell Rep ; 40(2): 351-359, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33247387

RESUMO

KEY MESSAGE: Identification of an EST-SSR molecular marker associated with Blister blight, a common fungal disease of tea, facilitating marker-assisted selection, marking a milestone in tea molecular breeding. lister blight (BB) leaf disease of tea, caused by the fungus Exobasidium vexans, results in 25-30% crop loss annually. BB is presently controlled by Cu based fungicides, but genetic resistance is the most viable option in disease management. Tea is a naturally out-crossing, woody perennial necessitating a long time for completion of a breeding programme. Marker-assisted selection (MAS) is vital to expedite breeding programmes and also for better accuracy in gene identification. The aim of the current research was to derive marker-trait associations using an F1 population segregating for BB. The population was genotyped at 11 expressed sequence tag simple sequence repeat loci followed by detecting the alleles by fragment analysis. The genotypic and phenotypic data were subjected to single-marker analysis resulting in the identification of EST-SSR073 as a diagnostic marker amplifying three alleles of the sizes, 168, 170 and 190 bp in F1. Of them, alleles 190 and 168 bp were confirmed to concur BB resistance and susceptibility, respectively. The alleles were validated in a panel of 64 tea cultivars, resulting in the amplification of 12 alleles at EST-SSR073. The EST-SSR073 allele sequences matched with Camellia sinensis photosystem-I reaction center subunit-II. The marker EST-SSR073 can be effectively used in breeding tea against BB, recording a milestone in MAS in tea.


Assuntos
Basidiomycota/fisiologia , Camellia sinensis/genética , Resistência à Doença/genética , Marcadores Genéticos/genética , Repetições de Microssatélites/genética , Doenças das Plantas/imunologia , Alelos , Camellia sinensis/imunologia , Camellia sinensis/microbiologia , Embaralhamento de DNA , Etiquetas de Sequências Expressas , Loci Gênicos/genética , Genótipo , Fenótipo , Melhoramento Vegetal , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Folhas de Planta/imunologia , Folhas de Planta/microbiologia , Chá
20.
J Sci Food Agric ; 101(3): 1182-1192, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32790067

RESUMO

BACKGROUND: Alfalfa (Medicago sativa L) is one of the most planted crops worldwide primarily used to feed animals. The use of alfalfa in human diet as sprouts, infusions and nutritional supplements is rapidly gaining popularity. Despite this, allergenicity assessment of this novel plant food is largely lacking. RESULTS: Here, leaf protein extract of alfalfa was studied using a combined proteomics, Immunoglobulin E (IgE)-binding inhibition assay and in silico approach to find potential allergens. We have identified and annotated 129 proteins using in-gel digestion proteomics and Blast2Go suit. A search against COMPARE database, using the identified proteins as query sequences, revealed high similarity with several allergenic proteins. The Single Point Highest Inhibition Achievable assay (SPHIAa) performed on the multiplex FABER® allergy testing system confirmed the in silico results and showed some additional potential allergens. This approach allowed the detection of proteins in alfalfa leaves cross-reacting with plant allergens from three different allergen families such as lipid transfer, thaumatin-like and Bet v 1-like protein families. In addition, the absence of structural determinants cross-reacting with seed storage allergenic proteins and with animal allergens was recorded. CONCLUSION: This study reports for the first time potential allergenic proteins in alfalfa. The results suggest that this plant food can be safely introduced, as a protein-rich supplement, in the diet of patients allergic to animal food allergens. Allergic patients towards certain plant food allergens need to be careful about consuming alfalfa because they might have allergic symptoms. © 2020 Society of Chemical Industry.


Assuntos
Alérgenos/imunologia , Imunoglobulina E/imunologia , Medicago sativa/imunologia , Alérgenos/química , Alérgenos/genética , Sequência de Aminoácidos , Simulação por Computador , Reações Cruzadas , Medicago sativa/química , Medicago sativa/genética , Folhas de Planta/química , Folhas de Planta/genética , Folhas de Planta/imunologia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/imunologia , Proteômica
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