scholarly journals Spatiotemporal and Quantitative Monitoring of the Fate of “Candidatus Phytoplasma Solani” in Tomato Plants Infected by Grafting

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 811
Author(s):  
Gaia Carminati ◽  
Vittorio Brusa ◽  
Alberto Loschi ◽  
Paolo Ermacora ◽  
Marta Martini

Understanding how phytoplasmas move and multiply within the host plant is fundamental for plant–pathogen interaction studies. In recent years, the tomato has been used as a model plant to study this type of interaction. In the present work, we investigated the distribution and multiplication dynamics of one strain of “Candidatus Phytoplasma (Ca. P.) solani”, (16SrXII-A) in tomato (Solanum lycopersicum L., cv. Micro-Tom) plants. We obtained infected plants by grafting, a fast and effective method to maintain phytoplasma infection. In planta spread and multiplication of “Ca. P. solani” was monitored over time using qualitative and quantitative qPCR. Root, apical shoot, lower leaves, and upper leaves were sampled at each sampling time. We hypothesized that “Ca. P. solani” from the grafting site reached firstly the highest leaf, the apex and the roots; subsequently, the phytoplasmas spread to the rest of the upper leaves and then progressively to the lower leaves. Significant differences were found in “Ca. P. solani” titer among different plant tissues. In particular, the concentration of phytoplasma in the roots was significantly higher than that in the other plant compartments in almost all the sampling dates. Since the roots show rapid colonization and the highest concentration of phytoplasmas, they represent the ideal tissue to sample for an early, sensitive and robust diagnosis.


Author(s):  
Gireesh Rajashekara ◽  
Loic Deblais ◽  
Sally A Miller

We investigated whether the co-occurrence of phytopathogens ( Clavibacter michiganensis  subsp.  michiganensis [ Cmm ] and  Xanthomonas gardneri  [ Xg ]) frequently encountered in tomato production and  Salmonella   enterica  subsp.  enterica  serotype Typhimurium (JSG626) affects the persistence of these pathogens in tomato plant tissues during the early stages of plant growth .  We observed that  Cmm  increased the persistence of  Salmonella  Typhimurium JSG626 (up to 1.8-log CFU/plant at 21 days post-inoculation; DPI) from co-inoculated tomato plants compared to plants inoculated with  S.  Typhimurium JSG626 alone (P<0.05).  Xg  had no effect on  S.  Typhimurium JSG626 persistence  in planta . The increased persistence of  S.  Typhimurium JSG626 was also observed when it was inoculated seven days after  Cmm  inoculation of the same plant tissues (P<0.05). On the other hand,  S.  Typhimurium JSG626 reduced the population of both  Cmm  and  Xg  (up to 1.5-log CFU/plant at 21DPI; P<0.05) in co-inoculated plants group compared to plants inoculated with  Cmm  or  Xg  alone. Further, the  Xg  population increased (1.16-log CFU/plant at 21DPI; P<0.05) when  S.  Typhimurium JSG626 was inoculated seven days after  Xg  inoculation compared to plants inoculated with  Xg  alone. Our findings demonstrate that the type of phytopathogen present in the phyllosphere and inoculation time influence the persistence of  S.  Typhimurium JSG626 and its interactions with phytopathogens co-colonized  in planta . Further,  Salmonella  seems to reduce the phytopathogen load in planta , while  Cmm  enhances the persistence of  Salmonella  from the co-inoculated plant tissues; however, further investigations are needed to understand mechanisms behind these interactions.



2019 ◽  
pp. 38-48
Author(s):  
L.R. Khakimova ◽  
A.M. Lavina ◽  
L.R. Karimova ◽  
V.V. Fedyaev ◽  
An.Kh. Baymiev ◽  
...  

A Pseudomonas sp. 102 strain, which is highly resistant to toxic effects of cadmium and has plant growth-promoting activity, can significantly increase growth parameters and biomass of tomato plants, including those observed under toxic effects of cadmium. The greatest positive effect was observed in plants transformed with the bacterial adhesin gene rapA1, the product of which is important for colonization of plant roots by bacteria. It was also shown that shoots of transgenic tomato plants accumulated the greatest amount of cadmium during inoculation with Pseudomonas sp. 102. The ability to extract high concentrations of cadmium and accumulate a large biomass under stress opens up prospects for the further use of associative interactions between tomato and Pseudomonas for phytoremediation. phytoremediation, cadmium, tomato, Pseudomonas, inoculation, agglutinins, This study was carried out using the equipment of the Biomika Centre for Collective Use of the Institute of Biochemistry and Genetics (Ufa Federal Research Centre, Russian Academy of Sciences) as part of the government task (project no. AAAA-A16-1160203500284). This study was supported by the Russian Foundation for Basic Research (project nos. 18-34-20004 and 18-34-00033) and 18-344-0033 mol_a_ved and 34-00033 mol_a).



Author(s):  
Mara Quaglia ◽  
Marika Bocchini ◽  
Benedetta Orfei ◽  
Roberto D’Amato ◽  
Franco Famiani ◽  
...  

AbstractThe purpose of this study was to determine whether zinc phosphate treatments of tomato plants (Solanum lycopersicum L.) can attenuate bacterial speck disease severity through reduction of Pseudomonas syringae pv. tomato (Pst) growth in planta and induce morphological and biochemical plant defence responses. Tomato plants were treated with 10 ppm (25.90 µM) zinc phosphate and then spray inoculated with strain DAPP-PG 215, race 0 of Pst. Disease symptoms were recorded as chlorosis and/or necrosis per leaf (%) and as numbers of necrotic spots. Soil treatments with zinc phosphate protected susceptible tomato plants against Pst, with reductions in both disease severity and pathogen growth in planta. The reduction of Pst growth in planta combined with significantly higher zinc levels in zinc-phosphate-treated plants indicated direct antimicrobial toxicity of this microelement, as also confirmed by in vitro assays. Morphological (i.e. callose apposition) and biochemical (i.e., expression of salicylic-acid-dependent pathogenesis-related protein PR1b1 gene) defence responses were induced by the zinc phosphate treatment, as demonstrated by histochemical and qPCR analyses, respectively. In conclusion, soil treatments with zinc phosphate can protect tomato plants against Pst attacks through direct antimicrobial activity and induction of morphological and biochemical plant defence responses.



Toxins ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 285 ◽  
Author(s):  
Wanda Czyżewska ◽  
Marlena Piontek

The research presented in this manuscript concerns the evaluation of the effectiveness of microstrainers, which are designed to reduce the amount of plankton in treated surface water. The efficiency of microstrainer filtration analysis is very important for the proper course of the water-treatment process not only in the Water-Treatment Plant (WTP) in Zielona Góra (central western Poland) but also in other WTPs around the world. The qualitative and quantitative monitoring of the abundance of plankton including cyanobacteria during the particle-filtration process allows not only for the assessment of the potential cyanotoxic risk in surface water providing a source of drinking water, but also allows the evaluation of the action and the prevention of adverse impacts of microstrainers. Over four years of research, it was observed that the largest amount of cyanobacteria before microstrainer filtration took place in May. The dominant species was Limnothrix redeckei. The microstrainer removal of plankton and cyanobacteria was statistically significant. The quantity of removed plankton increased with its increasing content in raw water. The particle-filtration process, by reducing the amount of cyanobacteria, contributes to a decrease in intracellular microcystins.



2000 ◽  
Vol 29 (4) ◽  
pp. 849-854 ◽  
Author(s):  
Ronaldo Reis Jr. ◽  
Lima ◽  
Evaldo F. Vilela ◽  
Raimundo S. Barros

To accomplish systematic studies with coffee leafminer, it is necessary to establish a mass rearing system under artificial conditions. It is possible to rear this species, from egg to adult, under laboratory conditions, without using coffee seedlings but detached leaves maintained in vitro. Synthetic cytokinins are routinely used for maintenance of plant cell and plant tissues in vitro. Two plant growth regulators, benzyladenin and kinetin, in concentrations 10-6 and 10-7 M were used to mantain the leaves. Green leaves collected in the field were maintained in the solution to be tested. Distilled water served as control. The experiment lasted 30 days, a period longer than the necessary for the complete development of the insect. Both artificial cytokinines indeed increased the lifetime of the coffee leaves, maintaining them green and healthy. Leaves placed in the cages for oviposition were attractive to the insect, with significant number of eggs per leaf. In most cases, eggs resulted in individuals that completed the whole developmental cycle. Tests with regulator in different concentrations with healthy leaves showed efficiency. However, we believe that hormone concentrations to be used with mined leaves should be larger, because these when maintained at 10-7 M leaves did not present a satisfactory lifetime. Therefore, tests with mined leaves with different hormone concentrations should be made to find out the ideal concentration for leaf survival. In our laboratory we are successfully using 10-6 M benzyladenin for the maintenance of mined leaves.



2001 ◽  
Vol 183 (12) ◽  
pp. 3597-3605 ◽  
Author(s):  
Julie Tans-Kersten ◽  
Huayu Huang ◽  
Caitilyn Allen

ABSTRACT Ralstonia solanacearum, a widely distributed and economically important plant pathogen, invades the roots of diverse plant hosts from the soil and aggressively colonizes the xylem vessels, causing a lethal wilting known as bacterial wilt disease. By examining bacteria from the xylem vessels of infected plants, we found thatR. solanacearum is essentially nonmotile in planta, although it can be highly motile in culture. To determine the role of pathogen motility in this disease, we cloned, characterized, and mutated two genes in the R. solanacearum flagellar biosynthetic pathway. The genes for flagellin, the subunit of the flagellar filament (fliC), and for the flagellar motor switch protein (fliM) were isolated based on their resemblance to these proteins in other bacteria. As is typical for flagellins, the predicted FliC protein had well-conserved N- and C-terminal regions, separated by a divergent central domain. The predicted R. solanacearum FliM closely resembled motor switch proteins from other proteobacteria. Chromosomal mutants lackingfliC or fliM were created by replacing the genes with marked interrupted constructs. Since fliM is embedded in the fliLMNOPQR operon, the aphAcassette was used to make a nonpolar fliM mutation. Both mutants were completely nonmotile on soft agar plates, in minimal broth, and in tomato plants. The fliC mutant lacked flagella altogether; moreover, sheared-cell protein preparations from the fliC mutant lacked a 30-kDa band corresponding to flagellin. The fliM mutant was usually aflagellate, but about 10% of cells had abnormal truncated flagella. In a biologically representative soil-soak inoculation virulence assay, both nonmotile mutants were significantly reduced in the ability to cause disease on tomato plants. However, the fliC mutant had wild-type virulence when it was inoculated directly onto cut tomato petioles, an inoculation method that did not require bacteria to enter the intact host from the soil. These results suggest that swimming motility makes its most important contribution to bacterial wilt virulence in the early stages of host plant invasion and colonization.



2009 ◽  
Vol 99 (10) ◽  
pp. 1127-1134 ◽  
Author(s):  
Annett Milling ◽  
Fanhong Meng ◽  
Timothy P. Denny ◽  
Caitilyn Allen

Most strains of the bacterial wilt pathogen Ralstonia solanacearum are tropical, but race 3 biovar 2 (R3bv2) strains can attack plants in temperate zones and tropical highlands. The basis of this distinctive ecological trait is not understood. We compared the survival of tropical, R3bv2, and warm-temperate North American strains of R. solanacearum under different conditions. In water at 4°C, North American strains remained culturable the longest (up to 90 days), whereas tropical strains remained culturable for the shortest time (≈40 days). However, live/dead staining indicated that cells of representative strains remained viable for >160 days. In contrast, inside potato tubers, R3bv2 strain UW551 survived >4 months at 4°C, whereas North American strain K60 and tropical strain GMI1000 were undetectable after <70 days in tubers. GMI1000 and UW551 grew similarly in minimal medium at 20 and 28°C and, although both strains wilted tomato plants rapidly at 28°C, UW551 was much more virulent at 20°C, killing all inoculated plants under conditions where GMI100 killed just over half. Thus, differences among the strains in the absence of a plant host were not predictive of their behavior in planta at cooler temperatures. These data indicate that interaction with plants is required for expression of the temperate epidemiological trait of R3bv2.



1992 ◽  
Vol 38 (9) ◽  
pp. 883-890 ◽  
Author(s):  
Dennis P. Jackson ◽  
Douglas A. Gray ◽  
Vincent L. Morris ◽  
Diane A. Cuppels

The prototrophic Pseudomonas syringae pv. tomato mutant DC3481, which is the result of a single-site Tn5 insertion, cannot grow and cause disease on tomato plants and cannot use the major organic acids of tomato, i.e., citric, malic, succinic, and tartaric acids, as sole carbon sources. Although nonpathogenic, strain DC3481 can still induce a hypersensitive reaction in nonhost plants. We have identified a 30-kb fragment of P. syringae pv. tomato wild-type DNA that can complement this mutant. EcoRI fragments from this region were subcloned and individually subjected to functional complementation analysis. The 3.8-kb fragment, which was the site of the Tn5 insertion, restored pathogenicity and the ability to use all the major organic acids of tomato as carbon sources. It shares sequence homology with several P. syringae pathovars but not other bacterial tomato pathogens. Our results indicate that sequences on the 3.8-kb EcoRI fragment are required for both the ability to grow on tomato leaves (and thus cause disease) and the utilization of carboxylic acids common to tomato. The 3.8-kb fragment may contain a sequence (or sequences) that regulates both traits. Key words: Pseudomonas syringae pv. tomato, phytopathogenicity, Tn5, tricarboxylic acid metabolism, bacterial speck, growth in planta.



Retos ◽  
2015 ◽  
pp. 42-47
Author(s):  
Angeles Filgueira Perez

En el presente estudio se ha tratado de obtener una aproximación al perfil ideal del entrenador de alto rendimiento en atletismo. En el mundo del deporte de alta competición, el entrenador debe desarrollar funciones de maestro, técnico y líder, lo cual hace difícil delimitar sus competencias (conocimientos, habilidades y cualidades personales). Por tanto, la principal motivación de este trabajo es establecer el papel que debe desempeñar el entrenador para la preparación física, técnica, táctica, psicológica y moral del deportista de alto nivel. Para ello, se ha considerado como población objeto de estudio al conjunto de entrenadores de alto rendimiento que en el momento de la investigación estuviesen activo, ya que interesaba realizar este estudio desde su propia perspectiva. Los datos recogidos forman parte de una investigación más amplia, llevada a cabo mediante encuesta, para la que se diseñó un cuestionario de 78 preguntas en el que se abarcaban tres temas: el perfil del entrenador y del deportista, así como la figura del formador de entrenadores en el Practicum. En este trabajo nos centramos en el primer tema y el análisis de la información obtenida nos permite concluir que la que práctica totalidad de los entrenadores de atletismo consideran necesario dominar con precisión los aspectos técnico-metodológicos. Además, consideran que su ética profesional debe estar regida por los principios de autonomía y beneficencia, de modo que valores como la honestidad y la justicia deben primar en el desarrollo de sus funciones.Abstract: In the current study, we have tried to get an approximation of the ideal profile of high performance coaches in athletics. In the high-level sports world, the coach must develop the role of teacher, technician and leader,  which makes it difficult to delimit  his/her competencies (knowledge, skills and personal qualities). Therefore, the main motivation of this work is to define the role that the coach plays in relation  to the physical, technical, tactical, psychological and moral preparation of elite athletes. Keeping this aim as an objective, we have considered as the target population the high performance coaches who are active at the time of the investigation, since we were interested  in knowing their own perspective. The data that was collected is a part of a wider investigation, conducted by a survey, for which we designed a questionnaire of 78 questions divided on three topics: the profile of the coach and the athlete, as well as the figure of the coach educator in the Practicum. In this work, we focus on the first topic and the analysis of the information that we obtained allows us to conclude that almost all the track and field coaches find it necessary to dominate the technical and methodological aspects. They also consider that professional ethics must be governed by the principles of autonomy and care that values   like honesty and justice must prevail in the performance of their work.



Author(s):  
S. Artese ◽  
J. L. Lerma ◽  
J. Aznar Molla ◽  
R. M. Sánchez ◽  
R. Zinno

<p><strong>Abstract.</strong> The three-dimensional (3D) documentation and surveying of cultural heritage can be carried out following several geomatics techniques such as laser scanning and thermography in order to detect the original 3D shape after applying reverse engineering solutions. In almost all cases, the integration of data collected by different instruments is needed to achieve a successful and comprehensive 3D model of the as-built architectural shape of the historical building. This paper describes the operations carried out by the authors to determine the as-built 3D model of the Escuelas Pias Church, related namely to the dome and circular nave. After the description of the church and historical notes, attention will be driven to the indirect registration results obtained with three different laser scanning software packages, highlighting similarities and differences, and the consequences while generating meshes. The 3D model carried out will then be described and the results of some investigations with regard to the hypotheses about the design of the dome and the origin of the alterations will be presented.</p>



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