scholarly journals Characterization of Migration and Induced Resistance of Rhizobium Vitis Strain ARK-1, a Biological Control Agent Against Grapevine Crown Gall Disease

Author(s):  
Akira Kawaguchi ◽  
Yoshiteru Noutoshi

Abstract A nonpathogenic strain ARK-1 of Rhizobium vitis has an antagonistic activity toward tumorigenic (Ti) strain of R. vitis, a causal agent of grapevine crown gall disease, and works as a biocontrol agent. We have demonstrated that the gall formation was fully suppressed when ARK-1 was co-inoculated with Ti into the grapevine stem at a 1:1 ratio. For practical use of ARK-1 in agriculture, understanding the temporal dynamics of the bacterial habitat on host plants and the biocontrol property are needed in order to develop proper application methods. Here we demonstrated that the gall incidence by Ti was reduced to about 50% when ARK-1 was pre-inoculated at both upper and lower positions on the grapevine stem 3 cm away from the Ti-inoculation point 5 days before. The bacterial cell detection assay in the grapevine tissue revealed that ARK-1 could migrate at least 3 cm in 5 days. Inoculations of ARK-1 or Ti induced expression of marker genes for defense-related phytohormones such as salicylic acid, jasmonic acid, and ethylene in grapevine within 3 days but they were diminished by 6 days. Inoculation of Ti 5 days after ARK-1 pre-inoculation induced expression of the marker genes except for the LOX-9 gene in a basically similar way to those without the pre-inoculation, suggesting that ARK-1 did not induce typical acquired systemic resistance or induced systemic resistance in grapevine, while the transcript of LOX-9 was detected at 24 and 48 hours after the Ti inoculation when ARK-1 was pre-inoculated, unlike the un-inoculated condition. ARK-1 primed the induction of certain defense genes and it may take part in its biocontrol activity.

Author(s):  
Hangwei Xi ◽  
Joshua Grist ◽  
Maarten Ryder ◽  
Iain Searle

Crown gall disease in grapevine is caused by pathogenic strains of Allorhizobium vitis. A. vitis strain F2/5 is a non-pathogenic biocontrol agent that was previously shown to act as a biological control agent to crown gall disease and first isolated from South Africa. Here, we present the complete assembled genome and is 5.94 Mb in length with 5,414 predicted protein-coding sequences, has two circular chromosomes and five plasmids. The genome sequence has no detectable T-DNA border sequences and is missing key virulence genes which is consistent with the bacteria being non-pathogenic. The F2/5 genome sequence could contribute to understanding the molecular basis underlying the biocontrol activity.


2020 ◽  
Vol 33 (12) ◽  
pp. 1451-1453
Author(s):  
Yoshiteru Noutoshi ◽  
Atsushi Toyoda ◽  
Tomoya Ishii ◽  
Kirara Saito ◽  
Megumi Watanabe ◽  
...  

Crown gall disease in grapevine is caused by pathogenic strains of Rhizobium vitis with a tumor-inducing (Ti) plasmids. A nonpathogenic strain, VAR03-1 of R. vitis, has been isolated from the grapevine root of nursery stock and it was shown to act as a biological control agent to crown gall disease. Its disease-suppressive effect was observed even when it was coinoculated with the pathogen in a 1:1 ratio. Here, we present the complete genome data of R. vitis VAR03-1, assembled by sequencing reads obtained by both PacBio and Illumina technologies with annotation. This genome sequence could contribute to investigations of the molecular basis underlying the biocontrol activity as well as the root-colonization ability of this bacterial strain. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Anastasia Dimopoulou ◽  
Ioannis Theologidis ◽  
Burghard Liebmann ◽  
Kriton Kalantidis ◽  
Nikon Vassilakos ◽  
...  

AbstractThe success of Bacillus amyloliquefaciens as a biological control agent relies on its ability to outgrow plant pathogens. It is also thought to interact with its plant host by inducing systemic resistance. In this study, the ability of B. amyloliquefaciens MBI600 to elicit defense (or other) responses in tomato seedlings and plants was assessed upon the expression of marker genes and transcriptomic analysis. Spray application of Serifel, a commercial formulation of MBI600, induced responses in a dose-dependent manner. Low dosage primed plant defense by activation of SA-responsive genes. Suggested dosage induced defense by mediating synergistic cross-talk between JA/ET and SA-signaling. Saturation of tomato roots or leaves with MBI600 elicitors activated JA/ET signaling at the expense of SA-mediated responses. The complex signaling network that is implicated in MBI600-tomato seedling interactions was mapped. MBI600 and flg22 (a bacterial flagellin peptide) elicitors induced, in a similar manner, biotic and abiotic stress responses by the coordinated activation of genes involved in JA/ET biosynthesis as well as hormone and redox signaling. This is the first study to suggest the activation of plant defense following the application of a commercial microbial formulation under conditions of greenhouse crop production.


2017 ◽  
Vol 97 (1) ◽  
pp. 1-11
Author(s):  
Aditi Sharma ◽  
A. K. Gupta ◽  
K. Khosla ◽  
Rishi Mahajan ◽  
Bharti ◽  
...  

A non-pathogenic agrocin-producing native isolate ofAgrobacterium tumefaciensstrain UHFBA-218 was tested as a biological control agent against the peach crown gall. This strain was compatible with all the recommended pesticides used in stone fruits in the integrated pest management (IPM) module, except for copper oxychloride, which was detrimental to its growth. Upon artificial co-inoculation of 4-wk-old plants of tomato var. Solan Gola withA. tumefaciensstrain UHFBA-218 and tumorigenicA. tumefaciensstrain Peach 2E-10, out of the 27 isolates recovered, six were transconjugants showing selective acquisition of tumorigenic factors as made evident by amplification withiptandvirD2primers, whereas the rest of the isolates did not acquire any of these tumorigenic factors. A white stone powder-based formulation of this isolate (103.3 × 108cfu g-1) retained appreciable viability for up to 6 months at room temperature. When peach roots and seeds were soaked in cell suspensions of different doses of a white stone powder-based bioformulation of UHFBA-218 before planting in the field, the number of plants with tumours was reduced, with the lowest incidence of crown gall being observed in the 0.1% UHFBA-218 root dip treatment, i.e. 1.48% and 0.80% during the years 2013 and 2014, respectively. No incidence of crown gall was observed in the three seed dip treatments, i.e. 30-min dip in UHFBA-218 followed by 1 h of shade drying, stratified seeds dipped for 30 min in 0.1% suspensions of strains UHFBA-218 or K84 followed by 1 h of shade drying before sowing, as compared with 14.76% incidence in untreated plants.


2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Prasenjit Das ◽  
Debasis Mukherjee

Cholera still remains as a severe global threat and is currently spreading in Africa and other parts of the world. The role of lytic bacteriophage as an intervention of cholera outbreaks is investigated using a mathematical model. Dynamics of cholera is discussed on basis of the basic reproduction number . Conditions of Hopf bifurcation are also derived for a positive net growth rate of Vibrio cholerae. Stability analysis and numerical simulations suggest that bacteriophage may contribute to lessening the severity of cholera epidemics by reducing the number of Vibrio cholerae in the environment. Hence with the presence of phage virus, cholera is self-limiting in nature. By using phage as a biological control agent in endemic areas, one may also influence the temporal dynamics of cholera epidemics while reducing the excessive use of chemicals. We also performed stochastic analysis which suggests that the model system is globally asymptotically stable in probability when the strengths of white noise are less than some specific quantities.


Author(s):  
I. A. Kovaljova

Based on the grapevine genotypes of NSC “Tairov Research Institute of Viticulture and Wine-Making” analysis, traits collections have been created and registered, representing genotypes for breeding programs to obtain new varieties resistant to abiotic and biotic environmental factors (frost and phytopathogens) under conditions implementation of climate change scenarios, varieties with improved quality traits and seedless varieties. Genetic ordering of traits collections has begun on the basis of varieties molecular identification using microsatellite DNA markers (from 5 to 9 MC loci) and identification using DNA markers of genes of interest or gene complexes (primarily a trait of seedlessness). Microsatellite analysis made it possible to identify a total of about 80 genotypes, mainly the varieties breeded at the NSC “Tairov Research Institute of Viticulture and Wine-Making”, belonging to the traits collections of resistance and quality. Visual sanitary control of three traits collections showed a practical absence of virus diseases and grapevine crown gall disease symptoms. Sometimes symptoms similar to the phytoplasma infection manifestation were found. The data of virus diseases agents identification by ELISA showed the absence the most harmful viruses — grapevine fanleaf virus (GFLV) and grapevine leafroll virus 1 (GLRaV I) on 19 samples tested. From samples of resistance traits collection one sample was positive on grapevine leafroll virus 3 and two were positive on grapevine fleck virus (GfkV). These samples should be eliminated from further propagation and genetic material moving between germplasm repositories. The causative agent of grapevine crown gall disease (Agrobacterium vitis) was not detected on 14 samples of 3 traits collections tested by PCR. It has been determined that the sanitary status of grapevine traits collections practically corresponds to the European minimum sanitary requirements, genetic ordering of characteristic collections will be continued.


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