Publications by authors named "Ismael Rodrigo"
Viroids are small, non-coding RNA pathogens known for their ability to cause severe plant diseases. Despite their simple structure, viroids like Potato Spindle Tuber Viroid (PSTVd) can interfere with plant cellular processes, including transcriptional and post-transcriptional mechanisms, impacting plant growth and yield. In this study, we have investigated the role of the Target Of Rapamycin (TOR) signaling pathway in modulating viroid pathogenesis in tomato plants infected with PSTVd.
View Article and Find Full Text PDFHydroxylated monoterpenes (HMTPs) are differentially emitted by tomato (Solanum lycopersicum) plants resisting bacterial infection. We have studied the defensive role of these volatiles in the tomato response to bacteria, whose main entrance is through stomatal apertures. Treatments with some HMTPs resulted in stomatal closure and pathogenesis-related protein 1 (PR1) induction.
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- Biotic and abiotic stresses, such as drought and pathogens, limit crop productivity, leading to a need for sustainable agricultural strategies.
- Plants respond to stress by closing their stomata and releasing volatile organic compounds, with ()-3-hexenyl butyrate (HB) identified as a key natural inducer that enhances stomatal immunity.
- Research reveals that HB initiates defense responses independent of traditional pathways, improving water stress resilience and fruit productivity in tomatoes, and bolstering resistance against pathogen infections in both potato and tomato plants.
Article Synopsis
- - The study focuses on new plasmids designed to produce infectious viroid clones that use dimeric cDNAs for generating transcripts, which can replicate longer forms and can be made both in vitro and in vivo through different inoculation methods.
- - Results indicate that agro-inoculated plants showed more consistent and severe disease symptoms compared to other methods, with variations in viroid accumulation and form types influenced by the host and method without a direct correlation to symptom severity.
- - Key findings highlight ribosomal stress as a new indicator of disease caused by nuclear-replicating viroids, linked to increased defensive signaling and changes in ribosome biogenesis, supporting the new plasmid's effectiveness for future viroid-host interaction studies.
New strategies of control need to be developed with the aim of economic and environmental sustainability in plant and crop protection. Metabolomics is an excellent platform for both understanding the complex plant-pathogen interactions and unraveling new chemical control strategies. GC-MS-based metabolomics, along with a phytohormone analysis of a compatible and incompatible interaction between tomato plants and f.
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- - Citrus exocortis viroid (CEVd) affects citrus trees, and its impact has also been studied in tomatoes, causing ribosomal stress similar to the effects of the hormone ethylene.
- - The study examines how CEVd infection interacts with ethylene in specially developed tomato mutants that are insensitive to ethylene, looking at their infection susceptibility and defensive responses.
- - Findings reveal that these ethylene-insensitive mutants show greater susceptibility to CEVd, increased expression of defense and ethylene genes, and notable ribosomal stress, highlighting the significant role of ethylene in disease progression.
Article Synopsis
- Secondary metabolites are crucial for plant defense against biotic stress, and glycosylation, facilitated by glycosyltransferases like Twi1, is a key process for their modification.
- The study found that the tomato glycosyltransferase Twi1 acts on various secondary metabolites, confirming its role in plant glycosylation through in vitro tests.
- Transgenic tomato plants with silenced Twi1 gene showed increased vulnerability to the Tomato spotted wilt virus, highlighting its importance in regulating specific flavonoids that contribute to plant resistance.
Viroids are naked RNAs that do not code for any known protein and yet are able to infect plants causing severe diseases. Because of their RNA nature, many studies have focused on the involvement of viroids in RNA-mediated gene silencing as being their pathogenesis mechanism. Here, the alterations caused by the Citrus exocortis viroid (CEVd) on the tomato translation machinery were studied as a new aspect of viroid pathogenesis.
View Article and Find Full Text PDFBenzothiadiazole (BTH) is a functional analogue of the phytohormone salycilic acid (SA) involved in the plant immune response. NahG tomato plants are unable to accumulate SA, which makes them hypersusceptible to several pathogens. Treatments with BTH increase the resistance to bacterial, fungal, viroid, or viral infections.
View Article and Find Full Text PDFThe volatile esters of (Z)-3-hexenol with acetic, propionic, isobutyric, or butyric acids are synthesized by alcohol acyltransferases (AAT) in plants. These compounds are differentially emitted when tomato plants are efficiently resisting an infection with pv. .
View Article and Find Full Text PDFVolatile organic compounds (VOCs) emitted by plants are secondary metabolites that mediate the plant interaction with pathogens and herbivores. These compounds may perform direct defensive functions, i.e.
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- Tomato plants with the NahG transgene, which prevents salicylic acid (SA) buildup, exhibited severe disease symptoms when infected with Citrus Exocortis Viroid (CEVd) or Tomato Spotted Wilt Virus (TSWV), compared to the regular Money Maker plants.
- The use of acibenzolar-S-methyl, an agent that activates defenses downstream of the SA pathway, enhanced the resistance of NahG tomato plants to these viruses.
- Despite the lack of SA, NahG plants showed an earlier and stronger production of certain defense compounds and proteins, and produced higher levels of ethylene, highlighting the significance of SA in tomato plant defense against CEVd and TSWV.
Hydroxycinnamic acid amides (HCAA) are secondary metabolites involved in plant development and defense that have been widely reported throughout the plant kingdom. These phenolics show antioxidant, antiviral, antibacterial, and antifungal activities. Hydroxycinnamoyl-CoA:tyramine N-hydroxycinnamoyl transferase (THT) is the key enzyme in HCAA synthesis and is induced in response to pathogen infection, wounding, or elicitor treatments, preceding HCAA accumulation.
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- * Researchers focused on the role of silencing-related genes that are similar to those in Arabidopsis thaliana, tracking their activity during infections with the ToMV virus and CEVd viroid in tomatoes.
- * Results showed that SA and GA treatments significantly induced specific genes, particularly ToDCL2 and ToDCL4, suggesting that the enhanced resistance to RNA pathogens may stem from the activation of RNA silencing pathways through these compounds.
Viroids are single-stranded, circular, noncoding RNAs that infect plants, causing devastating diseases. In this work, we employed 2D DIGE, followed by MS identification, to analyze the response of tomato plants infected by Citrus exocortis viroid (CEVd). Among the differentially expressed proteins detected, 45 were successfully identified and classified into different functional categories.
View Article and Find Full Text PDF(1)H nuclear magnetic resonance (NMR)-based metabolomics has been applied to study the compatible interaction between tomato plants and Tomato Mosaic Virus (ToMV). A detailed time course of metabolic fingerprinting of ToMV-inoculated and non-inoculated systemically infected tomato leaves has provided a fundamental understanding of the metabolic state of the plant not only in response to ToMV infection, but also under various physiological conditions. By this analytical platform a total of 32 metabolites including amino/organic acids, sugars, phenylpropanoids, flavonoids and other miscellaneous compounds were detected.
View Article and Find Full Text PDFThe importance of salicylic acid (SA) in the signal transduction pathway of plant disease resistance has been well documented in many incompatible plant-pathogen interactions, but less is known about signalling in compatible interactions. In this type of interaction, tomato plants have been found to accumulate high levels of 2,5-dihydroxybenzoic acid (gentisic acid, GA), a metabolic derivative of SA. Exogenous GA treatments induce in tomato plants a set of PR proteins that differ from those induced by salicylic acid.
View Article and Find Full Text PDFProteinaceous aspartic proteinase inhibitors are rare in nature and are described in only a few plant species. One of them corresponds to a family of cathepsin D inhibitors (CDIs) described in potato (Solanum tuberosum), involving up to 15 isoforms with a high sequence similarity. In this work, we describe a tomato (Solanum lycopersicum) wound-inducible protein called jasmonic-induced protein 21 (JIP21).
View Article and Find Full Text PDFIn the present work we have studied the accumulation of gentisic acid (2,5-dihydroxybenzoic acid, a metabolic derivative of salicylic acid, SA) in the plant-pathogen systems, Cucumis sativus and Gynura aurantiaca, infected with either prunus necrotic ringspot virus (PNRSV) or the exocortis viroid (CEVd), respectively. Both pathogens produced systemic infections and accumulated large amounts of the intermediary signal molecule gentisic acid as ascertained by electrospray ionization mass spectrometry (ESI-MS) coupled on line with high performance liquid chromatography (HPLC). The compound was found mostly in a conjugated (beta-glucoside) form.
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