Enhanced 3-methoxytyramine levels in crown gall tumours and other undifferentiated plant tissues.
Ontology highlight
ABSTRACT:
SUBMITTER: Mitchell SD
PROVIDER: S-EPMC1144120 | biostudies-other | 1984 Aug
REPOSITORIES: biostudies-other
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Project description:A novel methionine-containing plasmid-determined compound, N2-(1-carboxyethyl)methionine (NCEM) has been identified in crown-gall tumours induced by octopine-type strains of Agrobacterium tumefaciens. NCEM is probably synthesized by octopine synthase. Cell-free preparations from octopine-type strains of A. tumefaciens can degrade NCEM; however, the bacterium cannot transport the compound into the cell, although these strains can take up and degrade the octopine family of opines.
| S-EPMC1152897 | biostudies-other
Project description:BackgroundCrown gall (CG) (Agrobacterium tumefaciens) and the root lesion nematodes (RLNs) (Pratylenchus vulnus) are major challenges faced by the California walnut industry, reducing productivity and increasing the cost of establishing and maintaining orchards. Current nematode control strategies include nematicides, crop rotation, and tolerant cultivars, but these methods have limits. Developing genetic resistance through novel approaches like RNA interference (RNAi) can address these problems. RNAi-mediated silencing of CG disease in walnut (Juglans regia L.) has been achieved previously. We sought to place both CG and nematode resistance into a single walnut rootstock genotype using co-transformation to stack the resistance genes. A. tumefaciens, carrying self-complimentary iaaM and ipt transgenes, and Agrobacterium rhizogenes, carrying a self-complimentary Pv010 gene from P. vulnus, were used as co-transformation vectors. RolABC genes were introduced by the resident T-DNA in the A. rhizogenes Ri-plasmid used as a vector for plant transformation. Pv010 and Pv194 (transgenic control) genes were also transferred separately using A. tumefaciens. To test for resistance, transformed walnut roots were challenged with P. vulnus and microshoots were challenged with a virulent strain of A. tumefaciens.ResultsCombining the two bacterial strains at a 1:1 rather than 1:3 ratio increased the co-transformation efficiency. Although complete immunity to nematode infection was not observed, transgenic lines yielded up to 79% fewer nematodes per root following in vitro co-culture than untransformed controls. Transgenic line 33-3-1 exhibited complete crown gall control and 32% fewer nematodes. The transgenic plants had thicker, longer roots than untransformed controls possibly due to insertion of rolABC genes. When the Pv010 gene was present in roots with or without rolABC genes there was partial or complete control of RLNs. Transformation using only one vector showed 100% control in some lines.ConclusionsCG and nematode resistance gene stacking controlled CG and RLNs simultaneously in walnuts. Silencing genes encoding iaaM, ipt, and Pv010 decrease CG formation and RLNs populations in walnut. Beneficial plant genotype and phenotype changes are caused by co-transformation using A. tumefaciens and A. rhizogenes strains. Viable resistance against root lesion nematodes in walnut plants may be accomplished in the future using this gene stacking technology.
| S-EPMC3852553 | biostudies-literature
Project description:Rahnella aquatilis strain HX2 has the ability to promote maize growth and suppress sunflower crown gall disease caused by Agrobacterium vitis, A. tumefaciens, and A. rhizogenes. Pyrroloquinoline quinone (PQQ), a cofactor of aldose and alcohol dehydrogenases, is required for the synthesis of an antibacterial substance, gluconic acid, by HX2. Mutants of HX2 unable to produce PQQ were obtained by in-frame deletion of either the pqqA or pqqB gene. In this study, we report the independent functions of pqqA and pqqB genes in relation to PQQ synthesis. Interestingly, both the pqqA and pqqB mutants of R. aquatilis eliminated the ability of strain HX2 to produce antibacterial substance, which in turn, reduced the effectiveness of the strain for biological control of sunflower crown gall disease. The mutation also resulted in decreased mineral phosphate solubilization by HX2, which reduced the efficacy of this strain as a biological fertilizer. These functions were restored by complementation with the wild-type pqq gene cluster. Additionally, the phenotypes of HX2 derivatives, including colony morphology, growth dynamic, and pH change of culture medium were impacted to different extents. Our findings suggested that pqqA and pqqB genes individually play important functions in PQQ biosynthesis and are required for antibacterial activity and phosphorous solubilization. These traits are essential for R. aquatilis efficacy as a biological control and plant growth promoting strain. This study enhances our fundamental understanding of the biosynthesis of an environmentally significant cofactor produced by a promising biocontrol and biological fertilizer strain.
| S-EPMC4263746 | biostudies-literature
Project description:BackgroundCrown gall disease, caused by the pathogenic bacterium Agrobacterium tumefaciens, is responsible for extensive economic losses in orchards. Cherry rootstock 'CDR-1' (Prunus mahaleb) shows high resistance but the mechanism remains unclear. Here, we examined the morphology of pathogen-infected root neck surface, determined the activity of 10 defense-related enzymes and the content of salicylic acid (SA) and jasmonic acid (JA), and also applied transcriptome analysis, transient expression and transgenic verification to explore the crown gall resistance genes in 'CDR-1' plants.ResultsIn our study, peroxidase increased in the first 10 days, while phenylalanine ammonialyase and lipoxygenase increased in the first 15 days post-infection. Four key enzymes in the AsA-GSH cycle also responded, to a certain extent; although JA content increased significantly after the treatment, the SA content did not. In a follow-up transcriptome analysis, the differentially expressed genes Pm4CL2, PmCYP450, PmHCT1, PmHCT2, and PmCAD were up-regulated. Based on the above results, we focused on the lignin biosynthetic pathway, and further measured lignin content, and found it increased significantly. The Pm4CL2 gene was used to conduct transient expression and transgenic experiments to verify its function in crown gall disease resistance. It showed the relative expression of the treatment group was almost 14-fold that of the control group at 12 h post-treatment. After the infection treatment, clear signs of resistance were found in the transgenic lines; this indicated that under the higher expression level and earlier activation of Pm4CL2, plant resistance was enhanced.ConclusionsThe crown gall resistance of 'CDR-1' is likely related to the lignin biosynthetic pathway, in which Pm4CL2 functions crucially during the plant defense response to the pathogen A. tumefaciens. The results thus offer novel insights into the defense responses and resistance mechanism of cherry rootstock 'CDR-1' against crown gall disease.
| S-EPMC7661173 | biostudies-literature
Project description:Crown gall is a soil-borne bacterial disease caused by Agrobacterium tumefaciens, leading to significant economic losses in many plant species. For the assessment of the biological and chemical products on crown gall, each plant's crown region and roots were wounded, and then were dipped into their respective treatments. After the treatments, the plants were inoculated with a suspension of pathogenic A. tumefaciens isolate FBG1034 and maintained in a greenhouse for six months to assess them for gall formation. A quantitative real-time PCR assay was performed to quantify the A. tumefaciens using the chvE gene. Biological products such as the Agrobacterium radiobacter strain K1026, and strains 1 and 2, resulted in the lowest average root gall diameter and significantly reduced the crown gall diameter to stem diameter ratio, and the chemical product copper octanoate reduced the number of crown and root galls as well as the crown and root gall diameter compared to the inoculated, non-treated control. Moreover, both the A. radiobacter strain K1026 and strain 1 treatments resulted in an approximately 85% and 65% reduction in crown and root gall incidence, respectively, in both of the trials compared to the inoculated, non-treated plants. The findings of this study indicate that the use of biological and chemical products could help to suppress crown and root gall disease in rose plants.
| S-EPMC11357299 | biostudies-literature
Project description:Here, we report the annotated, near-complete genome sequence of Allorhizobium vitis K377, a phytopathogenic Rhizobiales strain isolated from a grapevine in South Australia. The assembled genome sequence is 6.40 Mb long, with 5,855 predicted protein-coding sequences, 56 tRNAs, and 12 rRNAs, and contains ttuC (tartrate metabolism; chromosomal) and nopaline synthesis, uptake, and catabolic genes (tumor-inducing plasmid-encoded).
| S-EPMC8483665 | biostudies-literature
Project description:The reduction of the use chemical pesticides in agriculture is gaining importance as an objective of decision-makers in both politics and economics. Consequently, the development of technically efficient and economically affordable alternatives as, e.g., biological control agents or practices is highly solicited. Crown gall disease of dicotyledonous plants is caused by ubiquitous soil borne pathogenic bacteria of the Agrobacterium tumefaciens species complex, that comprises the species Agrobacterium fabrum and represents a globally relevant plant protection problem. Within the framework of a screening program for bacterial Agrobacterium antagonists a total of 14 strains were isolated from Tunisian soil samples and assayed for antagonistic activity against pathogenic agrobacteria. One particularly promising isolate, termed strain MBY2, was studied more in depth. Using a Multilocus Sequence Analysis (MLSA) approach, the isolate was assigned to the taxonomic species Bacillus velezensis. Strain MBY2 was shown to display antagonistic effects against the pathogenic A. fabrum strain C58 in vitro and to significantly decrease pathogen populations under sterile and non-sterile soil conditions as well as in the rhizosphere of maize and, to a lower extent, tomato plants. Moreover, the ability of B. velezensis MBY2 to reduce C58-induced gall development has been demonstrated in vivo on stems of tomato and almond plants. The present study describes B. velezensis MBY2 as a newly discovered strain holding potential as a biological agent for crown gall disease management.
| S-EPMC8205166 | biostudies-literature
Project description:Galls are novel plant structures that develop in response to select biotic stressors. These structures, extended phenotypes of the inducer, usually serve to protect and feed the inducer or its progeny. This life history strategy has evolved dozens of times, and tens of thousands of species - including many bacteria, fungi, nematodes, mites and insects - are capable of manipulating plants in this way. The variation in gall phenotypes is extraordinary across species but usually predictable for each species of inducer. We introduce here a new ontology, GallOnt, that facilitates consistent descriptions and the semantic representation of and reasoning over plant gall phenotype data. GallOnt was largely developed from ontologies in the Open Biological and Biomedical Ontology (OBO) Foundry and stands to connect plant gall phenotypes to knowledge derived from model plant systems, including genotype-phenotype and agricultural research. We also introduce the idea of a new gall data standard - Minimum Information for the Description of Galls (MIDG version 0.1) - as a starting point for discussions regarding cecidology best practices.
| S-EPMC11369494 | biostudies-literature
Project description:Little is known about the effect of the host on the genetic stability of bacterial plant pathogens. Crown gall, a plant disease caused by Agrobacterium tumefaciens, may represent a useful model to study this effect. Indeed, our previous observations on the natural occurrence and origin of nonpathogenic agrobacteria suggest that the host plant might induce loss of pathogenicity in populations of A. tumefaciens. Here we report that five different A. tumefaciens strains initially isolated from apple tumors produced up to 99% nonpathogenic mutants following their reintroduction into axenic apple plants. Two of these five strains were also found to produce mutants on pear and/or blackberry plants. Generally, the mutants of the apple isolate D10B/87 were altered in the tumor-inducing plasmid, harboring either deletions in this plasmid or point mutations in the regulatory virulence gene virG. Most of the mutants originating from the same tumor appeared to be of clonal origin, implying that the host plants influenced agrobacterial populations by favoring growth of nonpathogenic mutants over that of wild-type cells. This hypothesis was confirmed by coinoculation of apple rootstocks with strain D10B/87 and a nonpathogenic mutant.
| S-EPMC177092 | biostudies-other
Project description:Crown gall disease caused by Agrobacterium tumefaciens severely impacts the production of peach and other fruit trees. Several peach cultivars are partially resistant to A. tumefaciens, but little is known about the roles of endophytic microbiota in disease resistance. In the present study, the endophytic bacterial communities of resistant and susceptible peach cultivars "Honggengansutao" and "Okinawa" were analyzed using universal 16S rRNA gene amplicon sequencing in parallel with the cultivation and characterization of bacterial isolates. A total of 1,357,088 high-quality sequences representing 3,160 distinct operational taxonomic units (OTUs; Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes) and 1,200 isolates of 20 genera and 305 distinct ribotypes were collected from peach roots and twigs. It was found that factors including plant developmental stage, cultivar, and A. tumefaciens invasion strongly influenced the peach endophytic communities. The community diversity of endophytic bacteria and the abundance of culturable bacteria were both higher in the roots of the resistant cultivar, particularly after inoculation. Strikingly, the pathogen antagonists Streptomyces and Pseudomonas in roots and Rhizobium in twigs were most frequently detected in resistant plants. Our results suggest that the higher abundance and diversity of endophytic bacteria and increased proportions of antagonistic bacteria might contribute to the natural defense of the resistant cultivar against A. tumefaciens This work reveals the relationships between endophytic bacteria and disease resistance in peach plants and provides important information for microbiome-based biocontrol of crown gall disease in fruit trees.IMPORTANCEAgrobacterium tumefaciens as the causal agent of peach crown gall disease can be controlled by planting resistant cultivars. This study profiles the endophytic bacteria in susceptible and resistant peach cultivars, advancing our understanding of the relationships between endophytic bacterial communities and peach crown gall disease, with potential implications for other complex microbiome-plant-pathogen interactions. The resistant cultivar may defend itself by increasing the diversity and abundance of beneficial endophytic bacteria. The antagonists identified among the genera Streptomyces, Pseudomonas, and Rhizobium may have application potential for biocontrol of crown gall disease in fruit trees.
| S-EPMC6495757 | biostudies-literature