RESUMEN
The natural terpenoid citral has antifungal activity against multiple fungi, but its bioactivity against oomycetes is unclear. Therefore, this study investigated the antioomycete activity and mechanism of citral against Phytophthora capsici, a highly destructive invasive oomycete. Results showed that citral not only had a great inhibition on the mycelial growth of P. capsici (EC50 = 94.15 mg/L), but also had a significant inhibition on multiple spores, such as sporangia formation, zoospore discharge and zoospore germination. Citral at 4000 mg/L exhibited favorable protective (73.33%) and curative efficacy (55.11%) against pepper Phytophthora blight. Citral significantly damaged the hyphal morphology, disrupted the cell membrane integrity, increased the permeability of cell membrane, and increased the glycerol content in P. capsici. A total of 250 upregulated and 288 downregulated proteins were identified in iTRAQ-based quantitative proteomic analysis. Downregulated proteins were mostly enriched in pathways of ABC transporters, cyanoamino acid metabolism and starch and sucrose metabolism, suggesting an inhibition of citral on transmembrane transporter (e.g., ABC transporters) and pathogenicity (e.g., ß-glucosidases) proteins. Upregulated proteins were enriched in biosynthesis of unsaturated fatty acids, pyruvate metabolism and glycolysis/gluconeogenesis, suggesting an activation of citral on energy generation proteins, including acyl-CoA oxidase, D-lactate dehydrogenase, pyruvate kinase, acetyl-CoA synthetase and phosphoenolpyruvate carboxykinase. Biochemical and iTRAQ analysis suggested that cell membrane may be the target of citral in P. capsici.
Asunto(s)
Monoterpenos Acíclicos , Phytophthora , Phytophthora/efectos de los fármacos , Monoterpenos Acíclicos/farmacología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Antifúngicos/farmacología , Monoterpenos/farmacologíaRESUMEN
Fluoxapiprolin, a novel piperidinyl thiazole isoxazoline fungicide, was developed by Bayer Crop Science in 2012. Despite its well-documented inhibitory activity against plant pathogenic oomycetes such as Phytophthora capsici and Phytophthora infestans, limited information regarding its antifungal spectrum and protective and curative activity is available. Fluoxapiprolin exhibited strong inhibitory activity against Phytophthora spp. and several Pythium spp., with EC50 values ranging from 2.12 × 10-4 to 2.92 µg/mL. It was much more effective against P. capsici in inhibiting mycelial growth, sporangium production, and cystospore germination than at reducing zoospore release. Moreover, fluoxapiprolin displayed both protective and curative activity against P. capsici infection in pepper plants under greenhouse conditions, with systemic translocation capability confirmed by High Performance Liquid Chromatography (HPLC) analysis. The results demonstrated the strong inhibitory activity of fluoxapiprolin against economically important plant oomycete pathogens, including Phytophthora spp. and several Pythium spp., and its certain translocation activity in pepper plants.
Asunto(s)
Capsicum , Fungicidas Industriales , Phytophthora , Enfermedades de las Plantas , Fungicidas Industriales/farmacología , Phytophthora/efectos de los fármacos , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Capsicum/microbiología , Capsicum/efectos de los fármacos , Oomicetos/efectos de los fármacos , Pythium/efectos de los fármacosRESUMEN
Plasmid-mediated DNA transformation is a foundational molecular technique and the basis for most CRISPR-Cas9 gene editing systems. While plasmid transformations are well established for many agricultural Phytophthora pathogens, development of this technique in forest Phytophthoras is lacking. Given our long-term research objective to develop CRISPR-Cas9 gene editing in a forest pathogenic Phytophthora species, we sought to establish the functionality of polyethylene glycol (PEG)-mediated plasmid transformation in five species: P. cactorum, P. cinnamomi, P. cryptogea, P. ramorum, and P. syringae. We used the agricultural pathogen P. sojae, a species for which PEG-mediated transformations are well-established, as a transformation control. Using a protocol previously optimized for P. sojae, we tested transformations in the five forest Phytophthoras with three different plasmids: two developed for CRISPR-Cas9 gene editing and one developed for fluorescent protein tagging. Out of the five species tested, successful transformation, as indicated by stable growth of transformants on a high concentration of antibiotic selective growth medium and diagnostic PCR, was achieved only with P. cactorum and P. ramorum. However, while transformations in P. cactorum were consistent and stable, transformations in P. ramorum were highly variable and yielded transformants with very weak mycelial growth and abnormal morphology. Our results indicate that P. cactorum is the best candidate to move forward with CRISPR-Cas9 protocol development and provide insight for future optimization of plasmid transformations in forest Phytophthoras.
Asunto(s)
Sistemas CRISPR-Cas , Edición Génica , Phytophthora , Plásmidos , Polietilenglicoles , Transformación Genética , Phytophthora/genética , Phytophthora/patogenicidad , Plásmidos/genética , Polietilenglicoles/farmacología , Edición Génica/métodos , Bosques , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/parasitologíaRESUMEN
Five novel imidazole-functionalized chitosan derivatives 3a-3e were synthesized via addition reactions of chitosan with imidazole derivatives. The partial incorporation of imidazole moiety in chitosan were confirmed by FTIR, UV, 1H NMR, XRD, SEM and GPC. Meanwhile, the antifungal activity against three common plant pathogenic fungi: Phytophthora nicotianae (P. nicotianae), Fusarium graminearum (F. graminearum) and Rhizoctonia solani (R. solani), was assayed in vitro at 0.5 and 1.0 mg/mL by hyphal measurement, and the introduction of imidazole group can influence the antifungal activity. At 0.5 mg/mL, 3e inhibited P. nicotianae growth by 42 % and had an inhibitory index against R. solani of 50 %. Derivative 3e was more effective than unmodified chitosan whose antifungal index was 17 % against P. nicotianae and 22 % against R. solani. To our surprise, at 1.0 mg/mL, the inhibition rate of 3e against R. solani can reach 99 %, while the inhibition rate of chitosan is only 38 %. These results indicated that some imidazole chitosan derivatives with enhanced antifungal activities could serve as potential biomaterial for antifungal application.
Asunto(s)
Antifúngicos , Quitosano , Imidazoles , Pruebas de Sensibilidad Microbiana , Quitosano/química , Quitosano/farmacología , Quitosano/síntesis química , Imidazoles/química , Imidazoles/farmacología , Imidazoles/síntesis química , Antifúngicos/farmacología , Antifúngicos/síntesis química , Antifúngicos/química , Fusarium/efectos de los fármacos , Rhizoctonia/efectos de los fármacos , Phytophthora/efectos de los fármacosRESUMEN
The global food security crisis is partly caused by significant crop losses due to pests and pathogens, leading to economic burdens. Phytophthora palmivora, an oomycete pathogen, affects many plantation crops and costs over USD 1 billion each year. Unfortunately, there is currently no prevention plan in place, highlighting the urgent need for an effective solution. P. palmivora produces motile zoospores that respond to weak electric fields. Here, we show that external electric fields can be used to reduce root infection in two plant species. We developed two original essays to study the effects of weak electric fields on the interaction between P. palmivora's zoospores and roots of Arabidopsis thaliana and Medicago truncatula. In the first configuration, a global artificial electric field is set up to induce ionic currents engulfing the plant roots while, in the second configuration, ionic currents are induced only locally and at a distance from the roots. In both cases, we found that weak ionic currents (250-550 µA) are sufficient to reduce zoospore attachment to Arabidopsis and Medicago roots, without affecting plant health. Moreover, we show that the same configurations decrease P. palmivora mycelial growth in Medicago roots after 24 h. We conclude that ionic currents can reduce more than one stage of P. palmivora root infection in hydroponics. Overall, our findings suggest that weak external electric fields can be used as a sustainable strategy for preventing P. palmivora infection, providing innovative prospects for agricultural crop protection.
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Arabidopsis , Phytophthora , Enfermedades de las Plantas , Raíces de Plantas , Phytophthora/fisiología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Raíces de Plantas/microbiología , Raíces de Plantas/parasitología , Arabidopsis/microbiología , Medicago truncatula/microbiología , Electricidad , Productos Agrícolas/microbiología , Productos Agrícolas/parasitologíaRESUMEN
A new formulation that gradually released encapsulated Thuja plicata essential oil (TPEO) as an active component from a biopolymer matrix within a given period was obtained. Antimicrobial activity was determined in in-vitro tests where pure TPEO successfully inhibited the development of different Phytophthora species. The TPEO essential oil was encapsulated into the biopolymer matrix and an oil-in-water emulsion was formed. FTIR spectra analysis confirmed the formation of electrostatic interaction between these polymers, and hydrogen interactions between active components of TPEO and polymer chains. The stability of the emulsions was confirmed by zeta potential measurements, with a value of about 30 mV, even after 14 days of aging. UV-Vis spectra analysis revealed that >60 % of TPEO remained in the emulsion after 14 days of exposure to ambient conditions, whereas pure TPEO evaporated faster, and around 20 % remained after 6 days. Encapsulated TPEO almost completely inhibited the growth of Phytophthora species during the ten-day day's exposition being statistically significantly improved compared to fungicide treatment. It was demonstrated that the emulsion exhibited a prolonged antimicrobial effect and successfully suppressed the growth of Phytophthora species, and can be considered as a means of protection in forests and crops.
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Aceites Volátiles , Phytophthora , Phytophthora/efectos de los fármacos , Aceites Volátiles/farmacología , Aceites Volátiles/química , Biopolímeros/química , Biopolímeros/farmacología , Plaguicidas/química , Plaguicidas/farmacología , Raíces de Plantas/química , Emulsiones/química , Pruebas de Sensibilidad MicrobianaRESUMEN
Phytophthora capsici, a pathogenic oomycete, poses a serious threat to global vegetable production. This study investigated the role of protein arginine methylation, a notable post-translational modification, in the epigenetic regulation of P. capsici. We identified and characterized five protein arginine methyltransferases (PRMTs) in P. capsici, with a focus on four putative type I PRMTs exhibiting similar functional domain. Deletion of PcPRMT3, a homolog of PRMT3, significantly affected mycelial growth, asexual spore development, pathogenicity, and stress responses in P. capsici. Transcriptome analyses indicated that absence of PcPRMT3 disrupted multiple biological pathways. The PcPRMT3 deletion mutant displayed heightened susceptibility to oxidative stress, correlated with the downregulation of genes involved in peroxidase and peroxisome activities. Additionally, PcPRMT3 acted as a negative regulator, modulating the transcription levels of specific elicitins, which in turn affects the defense response of host plant against P. capsici. Furthermore, PcPRMT3 was found to affect global arginine methylation levels in P. capsici, implying potential alterations in the functions of its substrate proteins.
Asunto(s)
Phytophthora , Enfermedades de las Plantas , Proteína-Arginina N-Metiltransferasas , Phytophthora/patogenicidad , Phytophthora/genética , Proteína-Arginina N-Metiltransferasas/metabolismo , Proteína-Arginina N-Metiltransferasas/genética , Enfermedades de las Plantas/microbiología , Arginina/metabolismo , Estrés Oxidativo/genética , MetilaciónRESUMEN
In recent decades an extensive mortality and decline of Quercus suber populations mainly caused by Phytophthora cinnamomi has been observed. In the current study, a chestnut gene homologous to ginkbilobin-2 (Cast_Gnk2-like), which in Ginkgo biloba codifies an antifungal protein, was transferred into cork oak somatic embryos of three different embryogenic lines by Agrobacterium mediated transformation. The transformation efficiency varied on the genotype from 2.5 to 9.2%, and a total of 22 independent transformed lines were obtained. The presence of Cast_Gnk2-like gene in transgenic embryos was verified in all lines by PCR. The number of transgene copies was estimated by qPCR in embryogenic lines with high proliferation ability and it varied between 1 and 5. In addition, the expression levels of Cast_Gnk2-like gene were determined in the embryogenic lines, with higher levels in lines derived from the genotype ALM6-WT. Transgenic plants were obtained from all transgenic lines and evaluated after cold storage of the somatic embryos for 2 months and subsequent transfer to germination medium. In vitro tolerance tests made under controlled conditions and following zoospore treatment showed that plants overexpressing Cast_Gnk2-like gene improved tolerance against Pc when compared to wild type ones.
Asunto(s)
Phytophthora , Enfermedades de las Plantas , Plantas Modificadas Genéticamente , Quercus , Phytophthora/genética , Quercus/genética , Quercus/microbiología , Plantas Modificadas Genéticamente/genética , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/genética , Proteínas de Plantas/genética , Regulación de la Expresión Génica de las Plantas , Semillas/genética , Resistencia a la Enfermedad/genética , Transformación GenéticaRESUMEN
Arbuscular mycorrhizal fungi (AMF) and Chitooligosaccharide (COS) can increase the resistance of plants to disease. COS can also promote the symbiosis between AMF and plants. However, the effects of AMF & COS combined application on the rhizosphere soil microbial community of tobacco and the improvement of tobacco's resistance to black shank disease are poorly understood.·We treated tobacco with AMF, COS, and combined application of AMF & COS (AC), respectively. Then studied the incidence, physio-biochemical changes, root exudates, and soil microbial diversity of tobacco seedling that was inoculated with Phytophthora nicotianae. The antioxidant enzyme activity and root vigor of tobacco showed a regular of AC > AMF > COS > CK, while the severity of tobacco disease showed the opposite regular. AMF and COS enhance the resistance to black shank disease by enhancing root vigor, and antioxidant capacity, and inducing changes in the rhizosphere microecology of tobacco. We have identified key root exudates and critical soil microorganisms that can inhibit the growth of P. nicotianae. The presence of caprylic acid in root exudates and Bacillus (WdhR-2) in rhizosphere soil microorganisms is the key factor that inhibits P. nicotianae growth. AC can significantly increase the content of caprylic acid in tobacco root exudates compared to AMF and COS. Both AMF and COS can significantly increase the abundance of Bacillus in tobacco rhizosphere soil, but the abundance of Bacillus in AC is significantly higher than that in AMF and COS. This indicates that the combined application of AMF and COS is more effective than their individual use. These findings suggest that exogenous stimuli can induce changes in plant root exudates, regulate plant rhizosphere microbial community, and then inhibit the growth of pathogens, thereby improving plant resistance to diseases.
Asunto(s)
Quitosano , Micorrizas , Nicotiana , Oligosacáridos , Phytophthora , Enfermedades de las Plantas , Rizosfera , Plantones , Phytophthora/fisiología , Micorrizas/fisiología , Nicotiana/microbiología , Nicotiana/efectos de los fármacos , Oligosacáridos/metabolismo , Plantones/microbiología , Plantones/efectos de los fármacos , Plantones/metabolismo , Quitosano/farmacología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Quitina/análogos & derivados , Quitina/metabolismo , Microbiología del Suelo , Raíces de Plantas/microbiología , Raíces de Plantas/metabolismo , Resistencia a la Enfermedad/efectos de los fármacosRESUMEN
The Oomycetes fungus Phytophthora spp. which causes Abnormal leaf fall (ALF) disease poses a significant threat as one of the most devastating diseases affecting rubber trees in India. A total of 30 Phytophthora isolates were obtained from ALF-affected samples collected during the Southwest monsoon season of Kerala. The colony morphology of Phytophthora isolates revealed eight different types of growth patterns, with stellate, stellate striated, and petaloid patterns growing rapidly, whereas chrysanthemum pattern grew slowly. Sporangia were papillate to non-papillate in various shapes, and sporangiophores exhibited simple, simple sympodial, or irregularly branching patterns. Highly virulent isolates exhibited petaloid morphology and rapid growth rates. Regardless of their virulence, all isolates showed susceptibility to the fungicide metalaxyl. Under in vitro conditions, the highly virulent isolate (R17) from rubber caused severe infections in chili, brinjal, and tomato with brown water-soaked lesions. Sequence analysis and multi-locus phylogeny of Internal transcribed spacer (ITS), cCytochrome c oxidase 1 (COX 1), Heat shock protein 90 (HSP 90), and Ribosomal protein L10 (RPL 10) confirmed the pathogen as Phytophthora meadii. A comprehensive understanding of both morphological and molecular traits of P. meadii is crucial for precise identification and future genetic variability studies.
Asunto(s)
Hevea , Filogenia , Phytophthora , Enfermedades de las Plantas , India , Phytophthora/genética , Phytophthora/clasificación , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/parasitología , Hevea/microbiología , Hevea/parasitología , Tipificación de Secuencias Multilocus , Hojas de la Planta/microbiología , Hojas de la Planta/parasitología , Análisis de Secuencia de ADN , Virulencia , ADN Espaciador Ribosómico/genética , Prevalencia , Análisis por Conglomerados , Fungicidas Industriales/farmacología , Alanina/análogos & derivadosRESUMEN
The genus Phytophthora contains more than 100 plant pathogenic species that parasitize a wide range of plants, including economically important fruits, vegetables, cereals, and forest trees, causing significant losses. Global agriculture is seriously threatened by fungicide resistance in Phytophthora species, which makes it imperative to fully comprehend the mechanisms, frequency, and non-chemical management techniques related to resistance mutations. The mechanisms behind fungicide resistance, such as target-site mutations, efflux pump overexpression, overexpression of target genes and metabolic detoxification routes for fungicides routinely used against Phytophthora species, are thoroughly examined in this review. Additionally, it assesses the frequency of resistance mutations in various Phytophthora species and geographical areas, emphasizing the rise of strains that are resistant to multiple drugs. The effectiveness of non-chemical management techniques, including biological control, host resistance, integrated pest management plans, and cultural practices, in reducing fungicide resistance is also thoroughly evaluated. The study provides important insights for future research and the development of sustainable disease management strategies to counter fungicide resistance in Phytophthora species by synthesizing current information and identifying knowledge gaps.
Asunto(s)
Farmacorresistencia Fúngica , Fungicidas Industriales , Phytophthora , Enfermedades de las Plantas , Phytophthora/efectos de los fármacos , Phytophthora/genética , Fungicidas Industriales/farmacología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Enfermedades de las Plantas/parasitología , Farmacorresistencia Fúngica/genética , Mutación , AgriculturaRESUMEN
Plant recognition of pathogen-associated molecular patterns (PAMPs) is pivotal in triggering immune responses, highlighting their potential as inducers of plant immunity. However, the number of PAMPs identified and applied in such contexts remains limited. In this study, we characterize a novel PAMP, designated Ss4368, which is derived from Scleromitrula shiraiana. Ss4368 is specifically distributed among a few fungal genera, including Botrytis, Monilinia, and Botryotinia. The transient expression of Ss4368 elicits cell death in a range of plant species. The signaling peptides, three conserved motifs, and cysteine residues (C46, C88, C112, C130, and C148) within Ss4368 are crucial for inducing robust cell death. Additionally, these signaling peptides are essential for the protein's localization to the apoplast. The cell death induced by Ss4368 and its homologous protein, Bc4368, is independent of the SUPPRESSOR OF BIR1-1 (SOBIR1), BRI1-ASSOCIATED KINASE-1 (BAK1), and salicylic acid (SA) pathways. Furthermore, the immune responses triggered by Ss4368 and Bc4368 significantly enhance the resistance of Nicotiana benthamiana to Phytophthora capsici. Therefore, we propose that Ss4368, as a novel PAMP, holds the potential for developing strategies to enhance plant resistance against P. capsici.
Asunto(s)
Muerte Celular , Resistencia a la Enfermedad , Nicotiana , Moléculas de Patrón Molecular Asociado a Patógenos , Phytophthora , Enfermedades de las Plantas , Inmunidad de la Planta , Phytophthora/patogenicidad , Resistencia a la Enfermedad/genética , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/genética , Moléculas de Patrón Molecular Asociado a Patógenos/metabolismo , Nicotiana/microbiología , Nicotiana/genética , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Regulación de la Expresión Génica de las Plantas , Células Vegetales/metabolismo , Células Vegetales/microbiologíaRESUMEN
Lesion mimic mutants (LMMs) refer to the spontaneous formation of disease-like spots on leaves without any obvious pathogen infection. The LMM genes can regulate plant immunity, thus promoting the defense of crops against pathogens. However, there is a lack of systematic understanding of the regulatory mechanism of LMMs in wheat. This study identified a wheat LMM TaCAT2, a homolog of the Arabidopsis CAT2. The prediction of the cis-regulatory element revealed that TaCAT2 was involved in the response of plants to various hormones and stresses. RT-qPCR analysis indicated that TaCAT2 was significantly up-regulated by NaCl, drought, and Fusarium graminearum infection. Fluorescence microscopy showed that the TaCAT2 was localized to the peroxisome. Overexpression of TaCAT2 enhanced plant resistance to Phytophthora infestation and F. graminearum by constitutionally activating SA and JA pathways. VIGS of TaCAT2 enhanced the sensitivity of wheat to F. graminearum. Further, TaCAT2 enhanced stress resistance by scavenging the excessive ROS and increasing the activities of antioxidative enzymes. This study lays the basis for the functional identification of TaCAT2 and its applicability in the disease resistance of wheat.
Asunto(s)
Resistencia a la Enfermedad , Regulación de la Expresión Génica de las Plantas , Enfermedades de las Plantas , Proteínas de Plantas , Estrés Fisiológico , Triticum , Triticum/genética , Triticum/microbiología , Triticum/inmunología , Resistencia a la Enfermedad/genética , Resistencia a la Enfermedad/inmunología , Estrés Fisiológico/genética , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/inmunología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fusarium/patogenicidad , Fusarium/fisiología , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Plantas Modificadas Genéticamente/genética , Phytophthora/patogenicidad , Phytophthora/fisiología , Especies Reactivas de Oxígeno/metabolismo , SequíasRESUMEN
Plant cell walls are a critical site where plants and pathogens continuously struggle for physiological dominance. Here we show that dynamic remodeling of pectin methylesterification of plant cell walls is a component of the physiological and co-evolutionary struggles between hosts and pathogens. A pectin methylesterase (PsPME1) secreted by Phytophthora sojae decreases the degree of pectin methylesterification, thus synergizing with an endo-polygalacturonase (PsPG1) to weaken plant cell walls. To counter PsPME1-mediated susceptibility, a plant-derived pectin methylesterase inhibitor protein, GmPMI1, protects pectin to maintain a high methylesterification status. GmPMI1 protects plant cell walls from enzymatic degradation by inhibiting both soybean and P. sojae pectin methylesterases during infection. However, constitutive expression of GmPMI1 disrupted the trade-off between host growth and defense responses. We therefore used AlphaFold structure tools to design a modified form of GmPMI1 (GmPMI1R) that specifically targets and inhibits pectin methylesterases secreted from pathogens but not from plants. Transient expression of GmPMI1R enhanced plant resistance to oomycete and fungal pathogens. In summary, our work highlights the biochemical modification of the cell wall as an important focal point in the physiological and co-evolutionary conflict between hosts and microbes, providing an important proof of concept that AI-driven structure-based tools can accelerate the development of new strategies for plant protection.
Asunto(s)
Hidrolasas de Éster Carboxílico , Resistencia a la Enfermedad , Enfermedades de las Plantas , Hidrolasas de Éster Carboxílico/metabolismo , Hidrolasas de Éster Carboxílico/genética , Enfermedades de las Plantas/microbiología , Phytophthora , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Pared Celular/metabolismo , Pectinas/metabolismoRESUMEN
Asparagine (Asn, N)-linked glycosylation is an abundant post-translational modification in which Asn, typically in Nglyco-X-S/T; X ≠ P motifs, are modified with N-glycans. It has essential regulatory roles in multicellular organisms. In this study, we systematically investigate the function of three N-glycosylation motifs (Nglyco-A, Nglyco-D and Nglyco-S) previously identified in Phytophthora sojae, through site-directed mutagenesis and functional assays. In P. sojae expressing glycosylation-dead variants pre-PsDMAP1N70A (Nglyco-A motif) or PsADFN64A (Nglyco-D motif), zoospore release or cyst germination is impaired. In particular, the pre-PsDMAP1N70A mutant reduces DNA methylation levels, and the PsADFN64A mutant disrupts the actin forms, which could explain the decrease in pathogenicity after N-glycosylation is destroyed. Similarly, P. sojae expressing PsNRXN132A (Nglyco-S motif) shows increased sensitivity to H2O2 and heat. Through autophagy or 26S proteasome pathway inhibition assays, we found that unglycosylated pre-PsDMAP1N70A and PsADFN64A are degraded via the 26S proteasome pathway, while the autophagy pathway is responsible for PsNRXN132A clearance. These findings demonstrate that glycosylation of these motifs regulates the stability and function of glycoproteins necessary for P. sojae growth, reproduction and pathogenicity, which expands the scope of known N-glycosylation regulatory functions in oomycetes.
Asunto(s)
Actinas , Secuencias de Aminoácidos , Phytophthora , Phytophthora/genética , Phytophthora/metabolismo , Phytophthora/patogenicidad , Glicosilación , Actinas/metabolismo , Actinas/genética , Metilación de ADN , Procesamiento Proteico-Postraduccional , AutofagiaRESUMEN
Oomycete pathogens deliver many effectors to enhance virulence or suppress plant immunity. Plant immune networks are interconnected, in which a few effectors can trigger a strong defense response when recognized by immunity-related proteins. How effectors activate plant defense response remains poorly understood. Here we report Phytophthora capsici effector RxLR23KM can induce plant cell death and plant immunity. RxLR23KM specifically binds to ERD15La, a regulator of abscisic acid and salicylic acid pathway, and the binding intensity depends on the amino acid residues (K93 and M320). NbNAC68, a downstream protein of ERD15La, can stimulate plant immunity that is compromised after binding with ERD15La. Silencing of NbNAC68 substantially prevents the activation of plant defense response. RxLR23KM binds to ERD15La, releasing NbNAC68 to activate plant immunity. These findings highlight a strategy of plant defense response that ERD15La as a central regulator coordinates RxLR23KM to regulate NbNAC68-triggered plant immunity.
Asunto(s)
Arabidopsis , Phytophthora , Enfermedades de las Plantas , Inmunidad de la Planta , Phytophthora/patogenicidad , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/inmunología , Arabidopsis/inmunología , Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/microbiología , Nicotiana/metabolismo , Nicotiana/inmunología , Nicotiana/genética , Nicotiana/microbiología , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Ácido Salicílico/metabolismo , Oomicetos , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Ácido Abscísico/metabolismo , Regulación de la Expresión Génica de las PlantasRESUMEN
Phytophthora species are oomycetes that have evolved a broad spectrum of biological processes and improved strategies to cope with host and environmental challenges. A growing body of evidence indicates that the high pathogen plasticity is based on epigenetic regulation of gene expression linked to Phytophthora's rapid adjustment to endogenous cues and various stresses. As 5mC DNA methylation has not yet been identified in Phytophthora, the reversible processes of acetylation/deacetylation of histone proteins seem to play a pivotal role in the epigenetic control of gene expression in oomycetes. To explore this issue, we review the structure, diversity, and phylogeny of histone acetyltransferases (HATs) and histone deacetylases (HDACs) in six plant-damaging Phytophthora species: P. capsici, P. cinnamomi, P. infestans, P. parasitica, P. ramorum, and P. sojae. To further integrate and improve our understanding of the phylogenetic classification, evolutionary relationship, and functional characteristics, we supplement this review with a comprehensive view of HATs and HDACs using recent genome- and proteome-level databases. Finally, the potential functional role of transcriptional reprogramming mediated by epigenetic changes during Phytophthora species saprophytic and parasitic phases under nitro-oxidative stress is also briefly discussed.
Asunto(s)
Epigénesis Genética , Histonas , Phytophthora , Phytophthora/genética , Phytophthora/fisiología , Phytophthora/patogenicidad , Phytophthora/metabolismo , Histonas/metabolismo , Acetilación , Histona Desacetilasas/metabolismo , Histona Desacetilasas/genética , Histona Acetiltransferasas/metabolismo , Histona Acetiltransferasas/genética , FilogeniaRESUMEN
The discovery of readily available and easily modifiable new models is a crucial and practical solution for agrochemical innovation. Antifungal function-oriented fusion of triazole with the prevalidated lead (R)-LE001 affords a novel framework with a broad and enhanced antifungal spectrum. Characterized by the easy accessibility and adjustability of [1,2,4]triazolo[4,3-a]pyridine, modular fine-tuning provided a set of unprecedented leads (e.g., Z23, Z25, Z26, etc.) with superior antifungal potentials than the positive control boscalid. Candidate Z23 exhibited a more promising antifungal activity against Sclerotinia sclerotiorum, Botrytis cinerea, and Phytophthora capsici with EC50 values of 0.7, 0.6, and 0.5 µM, respectively. This candidate could effectively control boscalid-resistant B. cinerea strains and also exhibit good vivo efficacy in controlling gray mold. Noteworthily, both the SDH-inhibition and the efficiency against Oomycete P. capsici are quite distinct from that of the positive control boscalid. A molecular docking simulation also differentiates Z23 from boscalid. These findings highlight the potential of [1,2,4]triazolo[4,3-a]pyridine amide as a novel antifungal model.
Asunto(s)
Compuestos de Anilina , Ascomicetos , Botrytis , Fungicidas Industriales , Niacinamida , Phytophthora , Enfermedades de las Plantas , Triazoles , Fungicidas Industriales/química , Fungicidas Industriales/farmacología , Botrytis/efectos de los fármacos , Botrytis/crecimiento & desarrollo , Triazoles/química , Triazoles/farmacología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Niacinamida/química , Niacinamida/farmacología , Relación Estructura-Actividad , Phytophthora/efectos de los fármacos , Compuestos de Anilina/química , Compuestos de Anilina/farmacología , Ascomicetos/efectos de los fármacos , Ascomicetos/química , Estructura Molecular , Oxazoles/química , Oxazoles/farmacologíaRESUMEN
Phytophthora root rot (PRR), caused by Phytophthora medicaginis, is a major soil-borne disease of chickpea in Australia. Breeding for PRR resistance is an effective approach to avoid significant yield loss. Genetic resistance has been identified in cultivated chickpea (Cicer arietinum) and in the wild relative C. echinospermum, with previous studies identifying independent genetic loci associated with each of these sources. However, the molecular mechanisms associated with PRR resistance are not known. RNA sequencing analysis employed in this study identified changes in gene expression in roots of three chickpea genotypes grown hydroponically, early post-infection with P. medicaginis zoospores. Analyses of differentially expressed genes (DEG) identified the activation of a higher number of non-specific R-genes in a PRR-susceptible variety than in the resistant genotypes, suggesting a whole plant resistance response occurring in chickpea against the pathogen. Contrasting molecular changes in signaling profiles, proteolysis and transcription factor pathways were observed in the cultivated and wild Cicer-derived resistant genotypes. DEG patterns supported a hypothesis that increased root elongation and reduced adventitious root formation limit the pathogen entry points in the genotype containing the wild Cicer source of PRR resistance. Candidate resistance genes, including an aquaporin and a maltose transporter in the wild Cicer source and GDSL esterases/lipases in the cultivated source of resistance, were oppositely regulated. Increased knowledge of these genes and pathways will improve our understanding of molecular mechanisms controlling PRR resistance in chickpea, and support the development of elite chickpea varieties through molecular breeding approaches.
Asunto(s)
Cicer , Resistencia a la Enfermedad , Regulación de la Expresión Génica de las Plantas , Phytophthora , Enfermedades de las Plantas , Raíces de Plantas , Análisis de Secuencia de ARN , Cicer/genética , Cicer/microbiología , Cicer/fisiología , Phytophthora/fisiología , Phytophthora/patogenicidad , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/inmunología , Resistencia a la Enfermedad/genética , Raíces de Plantas/genética , Raíces de Plantas/microbiología , GenotipoRESUMEN
Small secreted peptides (SSPs), serving as signaling molecules for intercellular communication, play significant regulatory roles in plant growth, development, pathogen immunity, and responses to abiotic stress. Despite several SSPs, such as PIP, PSK, and PSY having been identified to participate in plant immunity, the majority of SSPs remain understudied, necessitating the exploration and identification of SSPs regulating plant immunity from vast genomic resources. Here we systematically characterized 756 putative SSPs across the genome of Nicotiana tabacum. 173 SSPs were further annotated as established SSPs, such as nsLTP, CAPE, and CEP. Furthermore, we detected the expression of 484 putative SSP genes in five tissues, with 83 SSPs displaying tissue-specific expression. Transcriptomic analysis of tobacco roots under plant defense hormones revealed that 46 SSPs exhibited specific responsiveness to salicylic acid (SA), and such response was antagonistically regulated by methyl jasmonate. It's worth noting that among these 46 SSPs, 16 members belong to nsLTP family, and one of them, NtLTP25, was discovered to enhance tobacco's resistance against Phytophthora nicotianae. Overexpression of NtLTP25 in tobacco enhanced the expression of ICS1, subsequently stimulating the biosynthesis of SA and the expression of NPR1 and pathogenesis-related genes. Concurrently, NtLTP25 overexpression activated genes associated with ROS scavenging, consequently mitigating the accumulation of ROS during the subsequent phases of pathogenesis. These discoveries indicate that these 46 SSPs, especially the 16 nsLTPs, might have a vital role in governing plant immunity that relies on SA signaling. This offers a valuable source for pinpointing SSPs involved in regulating plant immunity.