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Cell Jul 1982The A6S/2 tumor incited on tobacco by Agrobacterium tumefaciens harboring the octopine-type A6 Ti plasmid contains one insert of Ti-plasmid sequences (the T DNA). This...
The A6S/2 tumor incited on tobacco by Agrobacterium tumefaciens harboring the octopine-type A6 Ti plasmid contains one insert of Ti-plasmid sequences (the T DNA). This 13 kb insert is derived from a colinear sequence in the Ti plasmid (the T region) and becomes attached to plant DNA in the nucleus of the host cell. We have determined the DNA sequence encompassing the left end of the T region of the A6 Ti plasmid and the corresponding portion of the A6S/2 T DNA. The two sequences are identical for at least 806 bp. To the left of the divergence point, the tumor contains five partially overlapping sequences that are direct or inverted repeats of sequences to the right of the divergence point. The Ti plasmid contains only the right member of each of these repeats. We have also performed heteroduplex studies that indicate that this T DNA has a 520 bp inverted repeat of an internal sequence at the right end near its junction with plant DNA. The repeated sequences near the ends of the T DNA resemble the repeats of adenovirus type 12 sequences found near its junction with host DNA. We discuss data suggesting that the 23 bp to the immediate right of the divergence point of the A6 left junction form a site important in some step in the transfer of T-region DNA from the bacteria to the plant.
Topics: Base Sequence; Gene Expression Regulation; Genetic Linkage; Plant Tumors; Plasmids; Repetitive Sequences, Nucleic Acid; Rhizobium
PubMed: 7151163
DOI: 10.1016/0092-8674(82)90464-0 -
Plant Signaling & Behavior 2019Agrobacterium tumefaciens is a plant pathogen which provokes galls on roots and stems (crown-gall disease) and colonizes them. Two approaches combining omics were used...
Agrobacterium tumefaciens is a plant pathogen which provokes galls on roots and stems (crown-gall disease) and colonizes them. Two approaches combining omics were used to decipher the lifestyle of A. tumefaciens in plant tumors: an integrative approach when omics were used on A. tumefaciens cells collected from plant tumors, a deconvolution approach when omics were used on A. tumefaciens cells exploiting a single tumor metabolite in pure culture assay. This addendum highlights some recent results on the biotroph lifestyle of A. tumefaciens in plant tumors.
Topics: Agrobacterium tumefaciens; Gene Expression Regulation, Plant; Plant Roots; Plant Tumors; Plants, Genetically Modified; Transformation, Genetic
PubMed: 30774017
DOI: 10.1080/15592324.2019.1581562 -
Science (New York, N.Y.) Aug 1949
Topics: Animals; Insect Vectors; Oncogenic Viruses; Plant Tumors; Plant Viruses; Plants; Viruses
PubMed: 17755242
DOI: 10.1126/science.110.2850.162-a -
Molecular & General Genetics : MGG 1982The effect of a large number of Tn3 insertions in the vir region of the Ti plasmid pTiA6NC on the virulence of Agrobacterium was determined. The Vir- insertions were...
The effect of a large number of Tn3 insertions in the vir region of the Ti plasmid pTiA6NC on the virulence of Agrobacterium was determined. The Vir- insertions were mapped in three of the five loci that have been defined previously. Merodiploid Rec- strains carrying one insertion mutation on the Ti plasmid and another insertion mutation (or the homologous wild-type region) on a compatible plasmid were constructed and used in complementation tests for virulence in test plants. This analysis has revealed that there are ten units of gene expression, presumably transcription units in the vir region. Mutation in one of these units is confirmed to be dominant while those in all others are recessive. Co-infection of test plants with pairs of insertion mutants did not restore virulence.
Topics: DNA Restriction Enzymes; DNA, Bacterial; Escherichia coli; Genes, Bacterial; Phenotype; Plant Tumors; Plasmids; Rhizobium
PubMed: 6298572
DOI: 10.1007/BF00330043 -
Scientific American Nov 1959
Topics: Animals; Insecta; Neoplasms; Plant Tumors; Plants
PubMed: 14403420
DOI: 10.1038/scientificamerican1159-151 -
Pathologie Et Biologie Dec 1967
Topics: Bacteria; Neoplasms, Radiation-Induced; Oncogenic Viruses; Plant Tumors; Plant Viruses; Radiation Effects
PubMed: 4867330
DOI: No ID Found -
Journal of Chemical Ecology Jul 2014While plant galls can be induced by a variety of organisms, insects produce the most diverse and complex galls found in nature; yet, how these galls are formed is... (Review)
Review
While plant galls can be induced by a variety of organisms, insects produce the most diverse and complex galls found in nature; yet, how these galls are formed is unknown. Phytohormones have long been hypothesized to play a key role in gall production, but their exact role, and how they influence galls, has been unclear. Research in the past decade has provided better insight into the role of plant hormones in gall growth and plant defenses. We review and synthesize recent literature on auxin, cytokinins, and abscisic, jasmonic, and salicylic acids to provide a broader understanding of how these phytohormones might effect gall production, help plants defend against galls, and/or allow insects to overcome host-plant defenses. After reviewing these topics, we consider the potential for phytohormones to have facilitated the evolution of insect galls. More specialized research is needed to provide a mechanistic understanding of how phytohormones operate in gall-insect-plant interactions, but current evidence strongly supports phytohormones as key factors determining the success and failure of insect galls.
Topics: Abscisic Acid; Animals; Biological Evolution; Cytokinins; Host-Parasite Interactions; Indoleacetic Acids; Insecta; Plant Growth Regulators; Plant Tumors; Plants
PubMed: 25027764
DOI: 10.1007/s10886-014-0457-6 -
Virology Nov 1961
Topics: Antigens; Fluorescent Antibody Technique; Neoplasms; Oncogenic Viruses; Plant Tumors; Plants
PubMed: 14477896
DOI: 10.1016/0042-6822(61)90360-9 -
Gene Jan 2000Crown gall tumor disease in dicot plants is caused by Agrobacterium tumefaciens harboring a giant tumor-inducing (Ti) plasmid. Here, for the first time among...
Crown gall tumor disease in dicot plants is caused by Agrobacterium tumefaciens harboring a giant tumor-inducing (Ti) plasmid. Here, for the first time among agrobacterial plasmids, the nucleotide sequence of a typical nopaline-type Ti plasmid (pTi-SAKURA) was determined completely. In total, 195 open reading frames (ORFs) were estimated in the 206479 bp long sequence. 20 genes for conjugation, three for replication, 22 for pathogenesis and 37 for genetic colonization of host plants were found within two-thirds of the plasmid. These genes formed seven functional gene clusters with narrow inter-cluster spaces. In the remaining one-third of the plasmid, novel genes including homologs of mutT, Rhizobium nodQ and Sphingomonas ligE genes were found, which are likely to be responsible for the broad host range. Restriction fragment length variation indicates extreme plasticity of the part required for conjugational gene transfer and the above-mentioned one-third of the plasmid, even among closely related Ti plasmids.
Topics: Agrobacterium tumefaciens; Chromosome Mapping; DNA, Bacterial; Genes, Bacterial; Molecular Sequence Data; Open Reading Frames; Plant Tumors; Plasmids; Sequence Analysis, DNA
PubMed: 10721727
DOI: 10.1016/s0378-1119(99)00502-8 -
Annual Review of Entomology 2004Gall-inducing aphids are host specific in the gall stage. Most species alternate between trees (the primary host), where the gall is induced, and shrubs and grasses... (Review)
Review
Gall-inducing aphids are host specific in the gall stage. Most species alternate between trees (the primary host), where the gall is induced, and shrubs and grasses (secondary hosts). Parthenogenesis during most of their life cycle is interrupted by a single stage of sexual reproduction on the primary host. Apart from these general characteristics, galling aphids present some of the most complex and diverse life histories in the insect world. In this article I review the specialized characteristics of galling aphids, as well as their complex and diverse life histories, as reported in the past 20 years.
Topics: Adaptation, Physiological; Animals; Aphids; Host-Parasite Interactions; Life Cycle Stages; Parthenogenesis; Phylogeny; Plant Tumors; Population Dynamics; Species Specificity; Trees
PubMed: 14651461
DOI: 10.1146/annurev.ento.49.061802.123236