RESUMEN
Plants and pathogens are entangled in a continual arms race. Plants have evolved dynamic defence and immune mechanisms to resist infection and enhance immunity for second wave attacks from the same or different types of pathogenic species. In addition to evolutionarily and physiological changes, plant-pathogen interaction is also highly dynamic at the molecular level. Recently, an emerging quantitative mass spectrometry-based proteomics approach named data-independent acquisition (DIA), has been developed for the analysis of the proteome in a high-throughput fashion. In this study, the DIA approach was applied to quantitatively trace the change in the plant proteome from the early to the later stage of pathogenesis progression. This study revealed that at the early stage of the pathogenesis response, proteins directly related to the chaperon were regulated for the defence proteins. At the later stage, not only the defence proteins but also a set of the pathogen-associated molecular pattern-triggered immunity (PTI) and effector triggered immunity (ETI)-related proteins were highly induced. Our findings show the dynamics of the plant regulation of pathogenesis at the protein level and demonstrate the potential of using the DIA approach for tracing the dynamics of the plant proteome during pathogenesis responses.
Asunto(s)
Resistencia a la Enfermedad/inmunología , Enfermedades de las Plantas/inmunología , Proteoma/inmunología , Solanum lycopersicum/genética , Resistencia a la Enfermedad/genética , Interacciones Huésped-Patógeno/genética , Interacciones Huésped-Patógeno/inmunología , Solanum lycopersicum/crecimiento & desarrollo , Solanum lycopersicum/inmunología , Solanum lycopersicum/microbiología , Enfermedades de las Plantas/genética , Inmunidad de la Planta/genética , Proteoma/genética , Proteómica/métodos , Pseudomonas syringae/inmunología , Pseudomonas syringae/patogenicidadRESUMEN
Many important cell-to-cell communication events in multicellular organisms are mediated by peptides, but only a few peptides have been identified in plants. In an attempt to address the difficulties in identifying plant signaling peptides, we developed a novel peptidomics approach and used this approach to discover defense signaling peptides in plants. In addition to the canonical peptide systemin, several novel peptides were confidently identified in tomato (Solanum lycopersicum) and quantified to be induced by both wounding and methyl jasmonate (MeJA). A wounding or wounding plus MeJA-induced peptide derived from the pathogenesis-related protein 1 (PR-1) family was found to induce significant antipathogen and minor antiherbivore responses in tomato. This study highlights a role for PR-1 in immune signaling and suggests the potential application of plant endogenous peptides in efforts to defeat biological threats in crop production. As PR-1 is highly conserved across many organisms and the putative peptide from At-PR1 was also found to be bioactive in Arabidopsis thaliana, our results suggest that this peptide may be useful for enhancing resistance to stress in other plant species.
Asunto(s)
Péptidos/metabolismo , Proteínas de Plantas/metabolismo , Proteoma/metabolismo , Solanum lycopersicum/metabolismo , Acetatos/farmacología , Secuencia de Aminoácidos , Cromatografía Liquida , Ciclopentanos/farmacología , Resistencia a la Enfermedad/efectos de los fármacos , Resistencia a la Enfermedad/genética , Resistencia a la Enfermedad/inmunología , Interacciones Huésped-Patógeno/efectos de los fármacos , Interacciones Huésped-Patógeno/inmunología , Solanum lycopersicum/genética , Solanum lycopersicum/microbiología , Datos de Secuencia Molecular , Análisis de Secuencia por Matrices de Oligonucleótidos , Oxilipinas/farmacología , Péptidos/genética , Péptidos/farmacología , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Reguladores del Crecimiento de las Plantas/farmacología , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Hojas de la Planta/microbiología , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteoma/genética , Proteoma/farmacología , Proteómica , Pseudomonas syringae/inmunología , Pseudomonas syringae/fisiología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Estrés Mecánico , Espectrometría de Masas en Tándem , Transcriptoma/efectos de los fármacos , Transcriptoma/genética , Transcriptoma/inmunologíaRESUMEN
Phytoplasmas have the smallest genome among bacteria and lack many essential genes required for biosynthetic and metabolic functions, making them unculturable, phloem-limited plant pathogens. In this study, we observed that transgenic Arabidopsis (Arabidopsis thaliana) expressing the secreted Aster Yellows phytoplasma strain Witches' Broom protein11 shows an altered root architecture, similarly to the disease symptoms of phytoplasma-infected plants, by forming hairy roots. This morphological change is paralleled by an accumulation of cellular phosphate (Pi) and an increase in the expression levels of Pi starvation-induced genes and microRNAs. In addition to the Pi starvation responses, we found that secreted Aster Yellows phytoplasma strain Witches' Broom protein11 suppresses salicylic acid-mediated defense responses and enhances the growth of a bacterial pathogen. These results contribute to an improved understanding of the role of phytoplasma effector SAP11 and provide new insights for understanding the molecular basis of plant-pathogen interactions.
Asunto(s)
Arabidopsis/inmunología , Arabidopsis/microbiología , Proteínas Bacterianas/metabolismo , Fosfatos/deficiencia , Phytoplasma/metabolismo , Antocianinas/metabolismo , Arabidopsis/efectos de los fármacos , Arabidopsis/genética , Secuencia de Bases , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Genoma de Planta/genética , Homeostasis/efectos de los fármacos , Homeostasis/genética , Ácidos Indolacéticos/farmacología , MicroARNs/genética , MicroARNs/metabolismo , Anotación de Secuencia Molecular , Datos de Secuencia Molecular , Fenotipo , Phytoplasma/efectos de los fármacos , Enfermedades de las Plantas/microbiología , Reguladores del Crecimiento de las Plantas/metabolismo , Inmunidad de la Planta/efectos de los fármacos , Inmunidad de la Planta/genética , Hojas de la Planta/anatomía & histología , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/genética , Raíces de Plantas/anatomía & histología , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/metabolismo , Plantas Modificadas Genéticamente , Pseudomonas syringae/efectos de los fármacos , Pseudomonas syringae/fisiología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genéticaRESUMEN
Proteolytic activation of cytokines regulates immunity in diverse organisms. In animals, cysteine-dependent aspartate-specific proteases (caspases) play central roles in cytokine maturation. Although the proteolytic production of peptide cytokines is also essential for plant immunity, evidence for cysteine-dependent aspartate-specific proteases in regulating plant immunity is still limited. In this study, we found that the C-terminal proteolytic processing of a caspase-like substrate motif "CNYD" within Pathogenesis-related protein 1 (PR1) generates an immunomodulatory cytokine (CAPE9) in Arabidopsis. Salicylic acid enhances CNYD-targeted protease activity and the proteolytic release of CAPE9 from PR1 in Arabidopsis. This process involves a protease exhibiting caspase-like enzyme activity, identified as Xylem cysteine peptidase 1 (XCP1). XCP1 exhibits a calcium-modulated pH-activity profile and a comparable activity to human caspases. XCP1 is required to induce systemic immunity triggered by pathogen-associated molecular patterns. This work reveals XCP1 as a key protease for plant immunity, which produces the cytokine CAPE9 from the canonical salicylic acid signaling marker PR1 to activate systemic immunity.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Proteasas de Cisteína , Animales , Humanos , Proteínas de Arabidopsis/metabolismo , Ácido Aspártico/metabolismo , Caspasas/metabolismo , Cisteína/metabolismo , Proteasas de Cisteína/metabolismo , Péptido Hidrolasas/metabolismo , Inmunidad de la Planta , Ácido Salicílico/metabolismo , Xilema/metabolismoRESUMEN
Phytoplasmas are insect-transmitted intracellular plant bacterial pathogens that secrete effector molecules into host cells that interfere with the host's developmental or metabolic processes. Recently, the secreted Aster Yellows phytoplasma strain Witches' Broom protein11 (SAP11) has been shown to act as a virulence factor that alters the development, hormone biosynthesis, phosphate (Pi) homeostasis, and defense responses in the affected plants. We found that SAP11 undergoes proteolytic processing in planta and self-interaction in vitro. These biochemical studies provide foundational insights necessary for the functional characterization of SAP11; however, the biological relevance of post-translational cleavage and self-interaction of SAP11 to its role as a virulence factor warrants further investigation.