Papers by Juan Carlos Ricci
Defence responses triggered during the plant-pathogen interaction between strawberry (Fragaria x ananassa) and Colletotrichum acutatum
Plant Stress
Biotechnology Progress, 1990
Escherichia coli HB101 was grown in complex medium under anaerobic and aerobic conditions. Cells ... more Escherichia coli HB101 was grown in complex medium under anaerobic and aerobic conditions. Cells prepared under these two different conditions were characterized by two‐dimensional protein gel electrophoresis, by NMR measurements under identical (anaerobic) conditions, and by measuring the kinetics of glucose uptake and catabolite end‐product appearance in the medium under identical anaerobic conditions. Specific rates of glucose uptake and end‐product formation were significantly greater for the anaerobically grown cells, which also exhibited lower intracellular concentrations of sugar phosphates, nucleoside di‐and triphosphates, UDPG, and NAD(H). Two‐dimensional gel electrophoretic analyses reveal changes in the intracellular levels of proteins involved in pyruvate catabolism that have been observed previously for E. coli grown in minimal medium under aerobic and anaerobic conditions. Enzymes involved in the TCA cycle were not detected in cells grown aerobically or anaerobically i...
The Polar Flagellin of Azospirillum brasilense REC3 Induces a Defense Response in Strawberry Plants Against the Fungus Macrophomina phaseolina
Journal of Plant Growth Regulation
Microbe-associated molecular patterns (MAMPs) are conserved molecules able to trigger plant resis... more Microbe-associated molecular patterns (MAMPs) are conserved molecules able to trigger plant resistance. The aim of this work was to evaluate the capacity of Azospirillum brasilense REC3 polar flagellin AzFlap as a MAMP, eliciting biochemical, histological, and molecular defense responses that can provide strawberry plants protection against the pathogenic fungus Macrophomina phaseolina. Strawberry plants were treated with AzFlap on leaves or with the isolate REC3 on leaves or roots. Salicylic acid content, biofilm formation, callose and lignin depositions, stomatal closure, ROS, and the expression of defense-related genes such as FaPR1, FaCAT, FaRBOH-D, FaRBOH-F, FaCHI23, FaCHI2-2, and FaGSL5 were evaluated. Phytopathogenic assays in plants treated with AzFlap or REC3 and infected with M. phaseolina were also performed. Results showed that plants leaf treated with AzFlap or root treated with REC3 caused the accumulation of ROS, salicylic acid, callose, lignin, the increase of biofilm formation on leaves, and stomatal closure. The evaluation of the expression of genes associated to defense response indicated the activation of the innate immunity of strawberry plants. The level of gene expression was strongly time and treatment dependent, suggesting a complex regulation of defense signaling. Root inoculations with REC3 or foliar treatment with AzFlap were able to reduce plant mortality, showing the effectiveness of both treatments to control M. phaseolina. These results indicate that flagellin AzFlap from A. brasilense REC3 behaves as a MAMP that activates a defense response against M. phaseolina in strawberry plants.
AsES elicitor induces ethylene production, accelerates ripening, and prevents Botrytis cinerea rot in strawberry fruit
European Journal of Plant Pathology
Horticulturae
Brassinosteriods (BRs) have increasingly been used to improve the yields and quality of various c... more Brassinosteriods (BRs) have increasingly been used to improve the yields and quality of various crops. In this work we studied the effect of two brassinosteroids, BB16 and EP24, on the growth promotion of Fragaria ananassa plants under normal conditions or exposed to water or saline stress. The influence of both BRs on the plant development and fruit quality was evaluated when cultivated in semi-hydroponic conditions. A marked growth-promoting effect was observed with both compounds when plants were cultivated under normal irrigation conditions and under saline and water stresses. BB16 and EP24 yielded plants with a higher dry weight, root length and surface, a higher number and area of leaves, a higher total weight of fruits per plant, and a higher percentage of fruits of commercial quality. Additionally, a higher content of chlorophyll, number of leaves, and increased dry weight was detected in plants treated with both BRs and exposed to water and saline stresses. Finally, when ev...
Induction and suppression of the defense response mediated by two fungal derived molecules in strawberry plants
Acta Horticulturae, 2021
Seasonal Variation of Plant Defense Inductor Ellagitannins in Strawberry Leaves under Field Conditions for Phytosanitary Technological Applications
Journal of Agricultural and Food Chemistry, 2021
Many natural compounds can activate the plant immunity, and for this reason, they have attracted ... more Many natural compounds can activate the plant immunity, and for this reason, they have attracted special interest in crop disease management. Previously, we isolated from strawberry leaves an ellagitannin (HeT), which elicits plant defense responses. In this research, we investigated bioactive compounds from field-collected strawberry leaves capable of inducing defense responses in Arabidopsis thaliana against a bacterial pathogen. Methanolic extracts of strawberry leaves sampled at different months were obtained and compared. The highest content of total soluble phenolic compounds was found in the methanolic extracts of leaves sampled in December (DME). The defense response induced in A. thaliana by DME was attributed to two ellagitannins, the HeT and galloyl-HHDP-glucose. Both compounds exhibited phytoprotective effects against Pseudomonas viridiflava and induced the expression of PDF1.2 and PR1 genes. These results provide an economic value to strawberry leaves, normally discarded at the end of the harvest stage of the crop, as a raw material for plant health enhancer bioinputs.
Plant Biology, 2020
AsES (Acremonium strictum Elicitor Subtilisin) is a fungal elicitor that activates innate immun... more AsES (Acremonium strictum Elicitor Subtilisin) is a fungal elicitor that activates innate immunity conferring disease resistance in strawberry (Fragaria x ananassa Duch.), Arabidopsis, and other plant species. The aim of the present work was to evaluate the Accepted Article This article is protected by copyright. All rights reserved involvement of ethylene (ET) signalling pathway in AsES-mediated immune response in strawberry. ET production and expression of the genes responsible for ET synthesis, perception, and response, were measured after AsES treatment. The ROS (H 2 O 2) accumulation and immunity induced by AsES were studied after ET perception was blocked by 1-methylcyclopropene (1-MCP). Biochemical and molecular results showed that AsES induced a marked increase in local and systemic biosynthesis of ET, both in a biphasic manner. Blocking of ET perception by 1-MCP prior to AsES induction reduced production of ROS (H 2 O 2), and unables AsES to elicit defense against fungal pathogens of different lifestyles such as Botrytis cinerea (necrotrophic) and Colletotrichum acutatum (hemibiotrophic). These findings contribute to elucidate the mode of action of the novel elicitor subtilase AsES, specifically regarding the role of ET signalling in the activation of plant innate immunity in addition to the multitude of processes regulated by ET in plants.
Journal of Berry Research, 2019
BACKGROUND: Stable transformation, transient expression, and post-transcriptional gene silencing ... more BACKGROUND: Stable transformation, transient expression, and post-transcriptional gene silencing (PTGS) are powerful methodologies that allow exploration of gene function. OBJECTIVE: We aimed to apply these methodologies to strawberry leaves. Methods: the binary vectors pBIN19-sgfp, pBICdsGFP and pBIN61-P19 were transferred into A. tumefaciens EHA105 supervirulent strain by electroporation. The sgfp gene silencing was carried out in stably transformed GFP (green fluorescent protein) F. x ananassa Duch. cultivar 'Pájaro' strawberry plants by agroinfiltration. GFP-fluorescence was observed using a stereomicroscope (507 nm). RESULTS: We attained a GFP transgenic F. x ananassa plant that expresses the functional protein in all the tissues during a complete and normal life cycle. In planta sgfp transient expression and silencing have also been achieved in F. x ananassa cv. 'Pájaro' leaves of wild type and GFP transgenic plants, respectively. Agrobacterium-mediated transient expression was visualized as high intensity green fluorescent spots as early as 7 days post-agroinfiltration (dpa), peaking between 10 and 14 dpa and persisting as long as 24 dpa. A knockdown GFP phenotype was achieved by silencing using a dsGFP hairpin. CONCLUSION: This work contributes significantly to the reverse genetics field in strawberry, might help to gain knowledge in the analysis of functional promoters and thereby allow protein expression and silencing of genes. This will help to develop resistant plants expressing plant defense elicitors or silencing pathogen receptors and/or negative regulators of plant defense.
Scientia Horticulturae, 2020
Highlights Calcium plays a key role in the defense induced by brassinosteroids in plants. Cal... more Highlights Calcium plays a key role in the defense induced by brassinosteroids in plants. Calcium-sensor calmodulin-like (CML) proteins were identified in Fragaria ananassa. Brassinosteroids induce overexpression of CMLs and other defense related genes.
Boletín de la Sociedad Argentina de Botánica, 2018
The genus Duchesnea includes two species originally from India: D. indica and D. chrysantha. In N... more The genus Duchesnea includes two species originally from India: D. indica and D. chrysantha. In Northwestern Argentina the monitoring of wild strawberry-like species was carried out; during 2002-2016, many populations of D. indica and none of D. chrysantha were discovered. Red-and white-fruited plants of D. indica were collected from disturbed areas and ex situ conserved in greenhouse and in nursery conditions. Were also consulted materials from different national and international herbaria, and we only found reports of D. indica with red fruit for Argentina. In the present work, we report for the first time the presence of D. indica f. albocaput in Argentina and South America, cohabiting with populations of D. indica f. indica in the underwoods of Tucumán. This finding broadens the distribution range of D. indica f. albocaput, cited as endemic to Japan by Naruhashi 1992. The morphological and anatomical characters of the two botanical forms of D. indica (red fruit genotypes and white fruit genotypes) are also presented: fruit color, number of leaflets, and crystal form.
Scientia Horticulturae, 2018
Acremonium strictum Elicitor Subtilisin (AsES) is a natural elicitor capable of inducing disease ... more Acremonium strictum Elicitor Subtilisin (AsES) is a natural elicitor capable of inducing disease resistance in strawberry and Arabidopsis thaliana plants. In this paper, the effect of AsES on ripening and defense response in the climacteric fruit, avocado (Persea americana) was studied. With this purpose ethylene production, respiration rate, weight loss, firmness and soluble solids content were studied. The effect of AsES on natural infestation with local pathogens was also evaluated to assess its capacity to activate a defense response. Controls consisted in fruits treated with water, or treated with 1-Methylcyclopropane prior to AsES (1-MCP + AsES). Results showed that AsES treatment increases significantly ethylene production at early stages of ripening (3 days post treatment); while in fruits treated with water or 1-MCP + AsES the maximum production occurs later (6 and 7 days post treatment, respectively). Enhanced respiration rate, weight loss and soluble solids content, accompanied with the decreased in firmness were observed in fruits treated with AsES. Also, fruits treated with AsES halted the growth the opportunistic pathogens, whereas the protection effect was not observed when avocado fruit were pre-treated with 1-MCP, suggesting that the effect is due to the activation of the ET defense signaling pathway. These results uncover a potential use of AsES on the postharvest management of ripening, and open new research lines to study the relationship between fruit quality and induction of disease resistance in AsES-treated fruit.
Colletotrichum acutatum M11 can suppress the defence response in strawberry plants
Planta, 2019
Main conclusionColletotrichum acutatum M11 produces a diffusible compound that suppresses the bio... more Main conclusionColletotrichum acutatum M11 produces a diffusible compound that suppresses the biochemical, physiological, molecular and anatomical events associated with the defence response induced by the plant defence elicitor AsES.AbstractThe fungal pathogen Colletotrichum acutatum, the causal agent of anthracnose disease, causes important economical losses in strawberry crop worldwide and synthetic agrochemicals are used to control it. In this context, the control of the disease using bioproducts is gaining reputation as an alternative of those toxic and pollutant agrochemicals. However, the success of the strategies using bioproducts can be seriously jeopardized in the presence of biological agents exerting a defence suppression effect. In this report, we show that the response defence induced in plant by the elicitor AsES from the fungus Acremonium strictum can be suppressed by a diffusible compound produced by isolate M11 of C. acutatum. Results revealed that strawberry plants treated with conidia of the isolated M11 or the culture supernatant of the isolate M11 suppress: ROS accumulation (e.g., H2O2, O2·− and NO), cell wall reinforcement (e.g., lignin and callose), and the up-regulation of defence-related genes (e.g., FaPR1, FaCHI23, FaPDF1.2, FaCAT, FaCDPK, FaCML39) induced by the elicitor AsES. Additionally, we show that the defence suppressing effect causes a systemic sensitization of plants. Results presented here highlights the necessity to make an integral study of the microbiome present in soils and plant biosphere before applying defence activation bioproducts to control crop diseases.
European Journal of Plant Pathology, 2019
Brassinosteroids (BRs) are steroidal compounds involved in plant growth and development. The aim ... more Brassinosteroids (BRs) are steroidal compounds involved in plant growth and development. The aim of this work was to evaluate the effect of 24-epibrassinolide (EP24) and a brassinosteroid spirostanic analogue DI-31 (BB16) on growth promotion, defense and fruit quality of strawberry (Fragaria x ananassa). Results showed that both BRs cause an increase in the leaf greenness, number of leaves and stolons, and the foliar area as compared to control plants. However, whereas plants treated with BB16 exhibited a dry weight increase, plants treated with EP24 did not show significant differences with respect to control plants. The effect of both BRs on the activation of a defense response was also evaluated in strawberry plants, and results revealed that both BRs exert a protective effect against Botrytis cinerea the causal agent of the gray mold disease. The effect of both BRs was also evaluated on strawberry fruits. Results showed that both BRs also reduced the incidence of postharvest infection due to native pathogens. It was further observed that both BRs were more effective at lower concentration (i.e. 0.1 mg l −1). When analyzing the influence of BB16 and EP24 on the quality of the postharvest fruit, it was found that the treatment with both BRs yield fruits with lower acidity, and higher content of soluble solids on the third day after treatment. In addition, lower weight loss, and higher colour quality (i.e. lightness and intensity) were observed in treated fruits as compared with control fruits. These results suggest that BRs could be used as a new crop management strategy, and as alternative to agrochemicals.
FEBS open bio, 2018
Plant secondary metabolism produces a variety of tannins that have a wide range of biological act... more Plant secondary metabolism produces a variety of tannins that have a wide range of biological activities, including activation of plant defenses and antimicrobial, anti-inflammatory and antitumoral effects. The ellagitannin HeT (1--galloyl-2,3;4,6-bis-hexahydroxydiphenoyl-β-d-glucopyranose) from strawberry leaves elicits a strong plant defense response, and exhibits antimicrobial activity associated to the inhibition of the oxygen consumption, but its mechanism of action is unknown. In this paper we investigate the influence of HeT on bacterial cell membrane integrity and its effect on respiration. A β-galactosidase unmasking experiment showed that HeT does not disrupt membrane integrity. Raman spectroscopy analysis revealed that HeT strongly interacts with the cell membrane. Spectrochemical analysis indicated that HeT is oxidized in contact with bacterial cell membranes, and functional studies showed that HeT inhibits oxygen consumption, NADH and MTT reduction. These results provid...
Plant Biology, 2014
The plant growth‐promoting strain REC3 of Azospirillum brasilense, isolated from strawberry roots... more The plant growth‐promoting strain REC3 of Azospirillum brasilense, isolated from strawberry roots, prompts growth promotion and systemic protection against anthracnose disease in this crop. Hence, we hypothesised that A. brasilense REC3 can induce different physiological, structural and molecular responses in strawberry plants. Therefore, the aim of this work was to study these traits activated in Azospirillum‐colonised strawberry plants, which have not been assessed until now. Healthy, in vitro micropropagated plants were root‐inoculated with REC3 under hydroponic conditions; root and leaf tissues were sampled at different times, and oxidative burst, phenolic compound content, malondialdehyde (MDA) concentration, callose deposition, cell wall fortification and gene expression were evaluated. Azospirillum inoculation enhanced levels of soluble phenolic compounds after 12 h post‐inoculation (hpi), while amounts of cell wall bound phenolics were similar in inoculated and control plant...
Molecular Plant-Microbe Interactions®, 2001
Fragarin, an antibiotic that was isolated and purified from a soluble fraction of strawberry leav... more Fragarin, an antibiotic that was isolated and purified from a soluble fraction of strawberry leaves, may be a new type of preformed antimicrobial compound (phytoanticipin). Here, we report that the growth and oxygen consumption of the phytopathogenic bacterium Clavibacter michiganensis were rapidly inhibited after the addition of fragarin to cultures. Also, dissipation of the membrane potential and an increase of cell membrane permeability were observed in the presence of fragarin. The ability of fragarin to dissipate the membrane potential was confirmed with the use of small unilamellar liposomes made with lipids extracted from C. michiganensis. Our results suggest that fragarin is able to act at the membrane level, and that this action is correlated with a decrease in cell viability.
World Journal of Microbiology and Biotechnology, 2009
Azospirillum brasilense (strains REC3, RLC1, PEC5) were root inoculated in strawberry plants of t... more Azospirillum brasilense (strains REC3, RLC1, PEC5) were root inoculated in strawberry plants of the cultivars 'Milsei', 'Selva' and 'Camarosa' to assess plant growth-promoting effects. The bacteria were able to promote plant growth (expressed as root length, root area, and dry weight of root and shoot), depending on the genotypes of plants and bacteria used, whereas the stolon production (3-4) depended only on the strawberry cultivar. To explain whether root exudates plays any role on the growth-promotion observed herein, total protein and sugar were determined, and chemotaxis properties were evaluated. The strains showed positive chemotaxis toward the root exudates, being influenced by the total sugars content, suggesting that the latter plays an important role in the chemotaxis effect and may contribute to enhance the root capacity to recruit azospirilla from rhizosphere, thus improving the growth-promoting effect exerted by these bacteria.
Protection of strawberry plants (Fragaria ananassa Duch.) against anthracnose disease induced by Azospirillum brasilense
Plant and Soil, 2011
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Papers by Juan Carlos Ricci