scholarly journals First Report of Agrobacterium vitis as Causal Agent of Crown Gall Disease of Grapevine in Tunisia

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 836-836 ◽  
Author(s):  
S. Chebil ◽  
R. Fersi ◽  
S. Chenenaoui ◽  
E. Abdellatif ◽  
G. Durante ◽  
...  

Since October 2011, a serious outbreak of crown gall disease was observed on 1- and 2-year-old grapevines (Vitis vinifera L.) cv. Superior Seedless in several vineyards located in the region of Regueb in the center of Tunisia. Fifty isolates of Agrobacterium were isolated on a tartrate medium from galls of affected plants. To prepare template DNA, cell suspensions were lysed in 0.25% sodium-azide (NaN3) buffer prepared in 1% Triton X-100 by heating the samples at 95°C for 10 to 15 min (1). The strains were differentiated using a multiplex PCR assay with a combination of VIRFF1/VIRFR2 and VIRD2S4F716/VIRD2S4R1036 primers (2), which detect regions of virF and virD2 genes, respectively, in A. vitis strains carrying octopine or nopaline Ti plasmids and A. vitis vitopine strains. In order to differentiate A. vitis strains from A. tumefaciens strains, PGF/PGR (4), a polygalacturonase specific primer set, was added to the mixture in multiplex PCR. The isolates segregated into three main groups. The first group carries octopine type Ti plasmids, the second carries vitopine type Ti plasmids, and the third group carries both octopine and vitopine type Ti plasmids. The polygalacturonase gene sequence from 10 isolates showed 94 to 97% identity to the sequences of A. vitis previously deposited in the NCBI GenBank database (Accession No. CP000633.1gb). The biochemical test results corresponded to the results of genetic analysis. The ability to aerobically convert lactose to 3-ketolactose was tested by spotting bacteria onto medium containing lactose and flooding plates with a layer of Benedict's reagents after incubation at 28°C for 48 h. Acid production from glucose was tested by spotting bacterial strains onto potato dextrose agar (PDA) medium supplemented with CaCO3. Alkali production from L-tartrate was tested by streaking bacteria on AB minimal medium supplemented with L-tartrate and growth in salt medium was tested by streaking on nutrient broth supplemented with 2% NaCl. All isolates except one were negative in 3-ketolactose. They were negative in acid clearing on PDA-CaCO3, grew in 2% NaCl, and produced alkali from tartarate. Pathogenicity of all 50 strains was tested on 1-month-old tomato plants (Lycopersicum esculentum cv. Riograndi). Plants were inoculated on the stem by pricking one to three times through a drop of inoculum (108 CFU/ml) at three inoculation sites. Sterile distilled water was used as control treatment. Plants were grown for 4 weeks at 23 ± 3°C and symptoms were recorded. Typical tumors developed at the inoculation sites and no symptoms were observed on the control plants. In Tunisia, crown gall disease was observed only on stone fruit trees and only A. tumefaciens Biovar 1 have been reported and assigned to four genomic species G4, G6 G7, and G8 basically on the recA sequencing (3). To our knowledge, this is the first report of A. vitis determined as the causal agent of grapevine crown gall in Tunisia. References: (1) A. Abolmaaty et al. Microbios 101:181, 2000. (2) F. Bini et al. Vitis 47:181, 2008. (3) D. Costechareyre et al. Microb. Ecol. 60:862, 2010. (4) E. Szegedi and S. Bottka. Vitis 41:37, 2002.

Plant Disease ◽  
2021 ◽  
Author(s):  
Huan-Yu Chen ◽  
Chun-Chi Lin ◽  
Chih-Wei Wang ◽  
NAI-CHUN LIN

Roselle (Hibiscus sabdariffa L.) plants, whose calyces are used for production of beverages or jams, are mainly cultivated in Taitung County of eastern Taiwan. Since 2016, large crown galls were observed on the roselle plants in the commercial plantations at Taimali and Jinfong Townships of Taitung County. A follow-up survey in July and August of 2017 revealed spreading of this disease to the neighboring areas including Beinan and Dawu Townships. Disease incidence was estimated to be 0.6-10%. Galls of varying sizes (2-15 cm in diameter) were usually found on the roots and crowns of the roselle plants, starting with small swellings at the infection sites. Galls were light-colored, and smooth and tender in texture at the early stage, but later turned dark-colored, and appeared rough and woody. In some cases, adventitious roots extruding from the larger crown galls could be seen. Isolation of the causal agent was performed by quadrantally streaking bacterial suspension made from surface-sterilized, macerated galls on trypticase soy agar (TSA). After incubating at 28°C for 5 days, single colonies were transferred onto new TSA plates for further cultivation at 28°C. Finally, circular, convex, viscous and milky white colonies with smooth surface similar to colony morphology of Agrobacterium tumefaciens C58 were obtained for further identification. First, all six candidate isolates (TZ-1, TL1-2, TL2-1, TD1-1, TD1-24 and TD2-1) were identified as Agrobacterium spp. using the partial sequences of the 16S rRNA gene (accession numbers MW205820 to MW205825 in the GenBank database). The selected isolates also showed some biochemical and physiological characteristics similar to A. tumefaciens, including oxidase positive, growth at 35°C and in 2% NaCl, and alkalinity from litmus milk. Moreover, they were tested negative for utilization of citrate and acid production on potato dextrose agar (PDA) supplemented with calcium carbonate. Under a transmission electron microscope, the bacterium was rod-shaped and possessed peritrichous flagella. By means of multiplex PCR using primers designed for differentiation of Agrobacterium rubi, Agrobacterium vitis and Agrobacterium biovars 1 and 2, a 184 bp product was detected in all six isolates, indicating that they all belong to Agrobacterium biovar 1. Furthermore, the recA allele of each isolate was PCR amplified using primers F2898/F2899, and recA sequence analysis assigned all six isolates to A. tumefaciens genomospecies G7 (GenBank accession numbers MZ570905-MZ570910). Pathogenicity assay was carried out by inoculating the stems of 2-week-old roselle seedlings through wounds made with a sterile needle with bacteria on it. The inoculated seedlings were kept in plastic bags to maintain high humidity. Symptoms similar to those observed in the field developed at the inoculation sites after 7 days, and Koch’s postulates were fulfilled when the bacteria re-isolated from the galls were also identified as A. tumefaciens genomospecies G7 using recA gene sequence analysis. To our knowledge, this is the first report of crown gall disease caused by A. tumefaciens on Hibiscus sabdariffa in Taiwan. This disease may potentially damage the roselle industry if no action is taken to stop its spreading. Identification of the causal agent of roselle crown gall disease could help us further investigate its ecology and develop integrated pest management strategies for prevention of this disease in the future.


Plant Disease ◽  
2012 ◽  
Vol 96 (2) ◽  
pp. 286-286 ◽  
Author(s):  
N. Kuzmanović ◽  
A. Ćalić ◽  
M. Ivanović ◽  
K. Gašić ◽  
J. Pulawska ◽  
...  

In November 2010, a serious outbreak of crown gall disease was observed on 3-year-old grapevine (Vitis vinifera L.) cv. Cabernet Sauvignon grafted onto Kober 5BB rootstock in two commercial vineyards located in the South Banat District in Serbia. Large, aerial tumors were visible above the grafting point on grapevine trunks, and in most cases, the tumors completely girdled the trunk. From the gall tissues, white, circular, and glistening bacterial colonies were isolated on yeast mannitol agar medium. Eight, nonfluorescent, gram-negative, and oxidase-positive strains were isolated from seven tumor samples and selected for further identification. PCR assays with A/C′ (1) and VCF3/VCR3 (4) primers corresponding to the virD2 and virC genes yielded 224- and 414-bp fragments, respectively, confirming that the strains harbored the plasmid responsible for pathogenicity. The strains were differentiated to the species/biovar level with a multiplex PCR assay targeting 23S rRNA gene sequences (3) and were identified as Agrobacterium vitis. The 16S rDNA gene sequence from one isolate (GenBank Accession No. JN185718) showed 99% identity to the sequences of A. vitis previously deposited in NCBI GenBank database. The physiological and biochemical test results corresponded to the results of genetic analysis (2). The strains grew at 35°C and in nutrient broth supplemented with 2% NaCl. They were negative in 3-ketolactose, acid clearing on PDA supplemented with CaCO3, and ferric ammonium citrate tests; nonmotile at pH 7.0; pectolytic at pH 4.5; utilized citrate; produced acid from sucrose and alkali from tartarate. Pathogenicity was confirmed by inoculation of three plants per bacterial strain on grapevine cv. Cabernet Franc and on a local cultivar of tomato (Lycopersicon esculentum L.). The plants were inoculated on the stem by pricking one to three times through a drop of inoculum (108 CFU/ml) at three inoculation sites. Sterile distilled water was used as a negative control. Inoculated plants were maintained in a greenhouse at 24 ± 3°C. Typical tumors developed at the inoculation sites on tomatoes 3 weeks after inoculation and on grapevine 6 weeks after inoculation. No symptoms were observed on the control plants. Bacteria were reisolated from tumorigenic tissues and identified as pathogenic A. vitis by PCR. Crown gall disease was sporadically observed in vineyards in Serbia in previous years, but did not cause significant damage. Therefore, the causal agent was not studied in detail. To our knowledge, this is the first report of A. vitis determined as the causal agent of grapevine crown gall in Serbia. References: (1) J. H. Haas et al. Appl. Environ. Microbiol. 61:2879, 1995. (2) L. W. Moore et al. Page 17 in: Laboratory Guide for Identification of Plant Pathogenic Bacteria. 3rd ed. N. W. Schaad et al., eds. The American Phytopathological Society, St. Paul, MN, 2001. (3) J. Pulawska et al. Syst. Appl. Microbiol. 29:470, 2006. (4) K. Suzaki et al. J. Gen. Plant Pathol. 70:342, 2004.


2012 ◽  
Vol 64 (4) ◽  
pp. 1487-1494 ◽  
Author(s):  
N. Kuzmanovic ◽  
Katarina Gasic ◽  
M. Ivanovic ◽  
Andjelka Prokic ◽  
A. Obradovic

In 2010, a serious outbreak of crown gall disease was observed on grapevines (Vitis vinifera L. cv. Cabernet Sauvignon) in several commercial vineyards located in the Vojvodina province, Serbia. Bacteria were isolated from the young tumor tissue on nonselective YMA medium and five representative strains were selected for further identification. Tumorigenic (Ti) plasmid was detected in all strains by PCR using primers designed to amplify the virC pathogenicity gene, producing a 414-bp PCR product. The strains were identified as Agrobacterium vitis using differential physiological and biochemical tests, and a multiplex PCR assay targeting 23S rRNA gene sequences. In the pathogenicity assay, all strains induced characteristic symptoms on inoculated tomato and grapevine plants. They were less virulent on tomato plants in comparison to the reference strains of A. tumefaciens and A. vitis.


Plant Disease ◽  
2010 ◽  
Vol 94 (8) ◽  
pp. 1064-1064 ◽  
Author(s):  
A. M. Alippi ◽  
A. C. Lopez ◽  
P. A. Balatti

From 2006 to 2009, crown gall and hairy root symptoms were observed on blueberry (Vaccinium corymbosum cvs. O'Neil, Millennia, and Misty) plants from six nurseries in Tucumán, Concordia, Pilar, Morón, and Baradero, Argentina. Bacteria were isolated from galls of all three cultivars and from hairy roots of Millenia and O'Neil onto D1 and D1M agar media at 27°C. Typical Agrobacterium colonies developed in 5 days (2). Seven bacterial strains (five from galls and two from hairy roots) were studied further. All were gram negative, aerobic, and catalase positive with rod-shaped cells that synthesized β–galactosidase and metabolized D-glucose, D-arabinose, n-acetyl-glucosamine, maltose, mannitol, and malonate. Strains were negative for lysine decarboxylase, H2S production, indole, and 3-ketolactose production. While gall strains were urease positive and citrate variable (mostly positive), hairy root strains were urease negative, citrate positive, had poly-β-hydroxybutyrate inclusion granules, and clarified acid on potato dextrose agar containing 0.5% CaCO3 (2). Agrobacterium tumefaciens ATCC 15955 and LBA 958 were included as controls. PCR with virA/C primers amplified a 338-bp product corresponding to the virD2 operon and confirmed that the strains harbored a pathogenic plasmid (1). Bacterial strains were assigned to biovars with a multiplex PCR assay targeting 23S rRNA sequences (3). Two strains produced PCR amplicons typical of A. rhizogenes bv. 2. The other five strains produced PCR amplicons typical of A. rubi, which were insensitive to agrocin in a bioassay with A. radiobacter strain K1026. Identity was confirmed by sequencing the 16S rDNA of strains F 266 (GenBank No. GU580894) and F 289 (No. GU580895), which had 99% homology to 16sRNA sequences of A. rubi ICMP 11833 (AY626395.1) and A. rhizogenes ATCC 11325 (AY945955.1), respectively. Pathogenicity of all seven strains was tested on V. corymbosum cv. Misty, Bryophyllum daigremontiana, tobacco cv. Xanthi, tomato cv. Presto, and pepper cv. California Wonder. Plants were inoculated by a needle stabbed into the stems with the appropriate cell suspension (108 CFU/ml) of each strain or with sterile distilled water (control treatment). Two plants of each species were tested per strain. Plants were grown for at least 45 days at 23 ± 3°C and symptoms were recorded. Inoculations with the five strains isolated from galls caused development of spherical, white to flesh-colored, rough, spongy wart-like galls at the inoculation sites. Root strains induced root proliferation on all inoculated plants as well as in a carrot disk bioassay (4). On blueberry plants, galls were dark brown to black, rough, and woody 6 months after inoculation. No lesions were observed on control plants. Bacteria were reisolated from symptomatic tissues of inoculated plants. Enterobacterial repetitive intergeneric consensus-PCR confirmed that the DNA fingerprints of the reisolated strains were identical to those of the original strains. To our knowledge, this is the first report of A. rubi and A. rhizogenes causing hairy root and crown gall on blueberry in Argentina. References: (1) J. H. Haas et. al. Appl. Environ. Microbiol. 61:2879,1995. (2) L. W. Moore et al. Page 17 in: Laboratory Guide for Identification of Plant Pathogenic Bacteria. 3rd ed. N. W. Schaad et al., eds. The American Phytopathological Society, St. Paul, MN, 2001. (3) J. Pulawska et al. Syst. Appl. Microbiol. 29:470, 2006. (4) M. H. Ryder et al. Plant Physiol. 77:215, 1985.


2015 ◽  
Vol 103 (2) ◽  
pp. 313 ◽  
Author(s):  
Janja LAMOVŠEK ◽  
Igor ZIDARIČ ◽  
Irena MAVRIČ PLEŠKO ◽  
Gregor UREK ◽  
Stanislav TRDAN

Agrobacterium vitis causes common grape vine (Vitis vinifera L.) crown gall disease that destroyed a lot of Slovenian vineyards more than a decade ago. Eighty isolates of Agrobacterium spp. collected during monitoring in 2006 were identified as A. vitis and A. tumefacies by pehA and multiplex PCR method. Tumor-inducing capacity of these strains was assessed on test plants and with PCR methods for detection of the Ti plasmid responsible for tumor induction. With VCF3/VCR3 primer pair six false negatives and no false positives were detected. The high genetic diversity of pathogenic Agrobacterium spp. strains affects the performance of molecular methods, thus biological test should be performed where results from molecular methods are doubtful.


2016 ◽  
Vol 82 (18) ◽  
pp. 5542-5552 ◽  
Author(s):  
Hanna Faist ◽  
Alexander Keller ◽  
Ute Hentschel ◽  
Rosalia Deeken

ABSTRACTCrown gall disease of grapevine is caused by virulentAgrobacteriumstrains and establishes a suitable habitat for agrobacteria and, potentially, other bacteria. The microbial community associated with grapevine plants has not been investigated with respect to this disease, which frequently results in monetary losses. This study compares the endophytic microbiota of organs from grapevine plants with or without crown gall disease and the surrounding vineyard soil over the growing seasons of 1 year. Amplicon-based community profiling revealed that the dominating factor causing differences between the grapevine microbiota is the sample site, not the crown gall disease. The soil showed the highest microbial diversity, which decreased with the distance from the soil over the root and the graft union of the trunk to the cane. Only the graft union microbiota was significantly affected by crown gall disease. The bacterial community of graft unions without a crown gall hosted transient microbiota, with the three most abundant bacterial species changing from season to season. In contrast, graft unions with a crown gall had a higher species richness, which in every season was dominated by the same three bacteria (Pseudomonassp.,Enterobacteriaceaesp., andAgrobacterium vitis). Forin vitro-cultivated grapevine plantlets,A. vitisinfection alone was sufficient to cause crown gall disease. Our data show that microbiota in crown galls is more stable over time than microbiota in healthy graft unions and that the microbial community is not essential for crown gall disease outbreak.IMPORTANCEThe characterization of bacterial populations in animal and human diseases using high-throughput deep-sequencing technologies, such as 16S amplicon sequencing, will ideally result in the identification of disease-specific microbiota. We analyzed the microbiota of the crown gall disease of grapevine, which is caused by infection with the bacterial pathogenAgrobacterium vitis.All otherAgrobacteriumspecies were found to be avirulent, even though they lived together withA. vitisin the same crown gall tumor. As has been reported for human cancer, the crown gall tumor also hosted opportunistic bacteria that are adapted to the tumor microenvironment. Characterization of the microbiota in various diseases using amplicon sequencing may help in early diagnosis, to serve as a preventative measure of disease in the future.


Plant Disease ◽  
2014 ◽  
Vol 98 (10) ◽  
pp. 1426-1426 ◽  
Author(s):  
O. Afolabi ◽  
B. Milan ◽  
R. Amoussa ◽  
R. Koebnik ◽  
L. Poulin ◽  
...  

On May 9, 2013, symptoms reminiscent of bacterial leaf streak (BLS) caused by Xanthomonas oryzae pv. oryzicola were observed on rice plants at the panicle emergence stage at Musenyi, Gihanga, and Rugombo fields in Burundi. Affected leaves showed water-soaked translucent lesions and yellow-brown to black streaks, sometimes with visible exudates on leaf surfaces. Symptomatic leaves were ground in sterile water and the suspensions obtained were subjected to a multiplex PCR assay diagnostic for X. oryzae pathovars (3). Three DNA fragments (331, 691, and 945 bp) corresponding to X. oryzae pv. oryzicola were observed after agarose gel electrophoresis. Single bacterial colonies were then isolated from surface-sterilized, infected leaves after grinding in sterile water and plating of 10-fold dilutions of the cell suspension on semi-selective PSA medium (4). After incubation at 28°C for 5 days, each of four independent cultures yielded single yellow, mucoid Xanthomonas-like colonies (named Bur_1, Bur_2, Bur_6, and Bur_7) that resembled the positive control strain MAI10 (1). These strains originated from Musenyi (Bur_1), Gihanga (Bur_2), and Rugumbo (Bur_6 and Bur_7). Multiplex PCR assays on the four putative X. oryzae pv. oryzicola strains yielded the three diagnostic DNA fragments mentioned above. All strains were further analyzed by sequence analysis of portions of the gyrB gene using the universal primers gyrB1-F and gyrB1-R for PCR amplification (5). The 762-bp DNA fragment was identical to gyrB sequences from the Asian X. oryzae pv. oryzicola strains BLS256 (Philippines), ICMP 12013 (China), LMG 797 and NCPPB 2921 (both Malaysia), and from the African strain MAI3 (Mali) (2). The partial nucleotide sequence of the gyrB gene of Bur_1 was submitted to GenBank (Accession No. KJ801400). Pathogenicity tests were performed on greenhouse-grown 4-week-old rice plants of the cvs. Nipponbare, Azucena, IRBB 1, IRBB 2, IRBB 3, IRBB 7, FKR 14, PNA64F4-56, TCS 10, Gigante, and Adny 11. Bacterial cultures were grown overnight in PSA medium and re-suspended in sterile water (1 × 108 CFU/ml). Plants were inoculated with bacterial suspensions either by spraying or by leaf infiltration (1). For spray inoculation, four plants per accession and strain were used while three leaves per plant and four plants per accession and strain were inoculated by tissue infiltration. After 15 days of incubation in a BSL-3 containment facility (27 ± 1°C with a 12-h photoperiod), the spray-inoculated plants showed water-soaked lesions with yellow exudates identical to those seen in the field. For syringe-infiltrated leaves, the same symptoms were observed at the infiltrated leaf area. Re-isolation of bacteria from symptomatic leaves yielded colonies with the typical Xanthomonas morphology that were confirmed by multiplex PCR to be X. oryzae pv. oryzicola, thus fulfilling Koch's postulates. Bur_1 has been deposited in the Collection Française de Bactéries Phytopathogènes as strain CFBP 8170 ( http://www.angers-nantes.inra.fr/cfbp/ ). To our knowledge, this is the first report of X. oryzae pv. oryzicola causing bacterial leaf streak on rice in Burundi. Further surveys will help to assess its importance in the country. References: (1) C. Gonzalez et al., Mol. Plant Microbe Interact. 20:534, 2007. (2) A. Hajri et al. Mol. Plant Pathol. 13:288, 2012. (3) J. M. Lang et al. Plant Dis. 94:311, 2010. (4) L. Poulin et al. Plant Dis. 98:1423, 2014. (5) J. M. Young et al. Syst. Appl. Microbiol. 31:366, 2008.


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