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PloS One 2019Insect herbivores can manipulate host plants to inhibit defenses. Insects that induce plant galls are excellent examples of these interactions. The Hessian fly (HF,...
Insect herbivores can manipulate host plants to inhibit defenses. Insects that induce plant galls are excellent examples of these interactions. The Hessian fly (HF, Mayetiola destructor) is a destructive pest of wheat (Triticum spp.) that occurs in nearly all wheat producing globally. Under compatible interactions (i.e., successful HF establishment), HF larvae alter host tissue physiology and morphology for their benefit, manifesting as the development of plant nutritive tissue that feeds the larva and ceases plant cell division and elongation. Under incompatible interactions (i.e., unsuccessful HF establishment), plants respond to larval feeding by killing the larva, permitting normal plant development. We used reflectance spectroscopy to characterize whole-plant functional trait responses during both compatible and incompatible interactions and related these findings with morphological and gene expression observations from earlier studies. Spectral models successfully characterized wheat foliar traits, with mean goodness of fit statistics of 0.84, 0.85, 0.94, and 0.69 and percent root mean square errors of 22, 10, 6, and 20%, respectively, for nitrogen and carbon concentrations, leaf mass per area, and total phenolic content. We found that larvae capable of generating compatible interactions successfully manipulated host plant chemical and morphological composition to create a more hospitable environment. Incompatible interactions resulted in lower host plant nutritional quality, thicker leaves, and higher phenolic levels. Spectral measurements successfully characterized wheat responses to compatible and incompatible interactions, providing an excellent example of the utility of Spectral phenotyping in quantifying responses of specific plant functional traits associated with insect resistance.
Topics: Animals; Diptera; Disease Resistance; Food Chain; Genes, Insect; Genes, Plant; Genotype; Herbivory; Host-Parasite Interactions; Plant Diseases; Plant Tumors; Spectrum Analysis; Stress, Physiological; Triticum
PubMed: 31437174
DOI: 10.1371/journal.pone.0219431 -
Genome Biology and Evolution Jun 2019Plasmids play a crucial role in the ecology of agrobacteria. In this study, we sequenced tumor-inducing (Ti) and opine-catabolic (OC) plasmids in three Rhizobium...
Plasmids play a crucial role in the ecology of agrobacteria. In this study, we sequenced tumor-inducing (Ti) and opine-catabolic (OC) plasmids in three Rhizobium rhizogenes (Agrobacterium biovar 2) strains isolated from the same crown gall tumor on "Colt" cherry rootstock and conducted comparative genomic analyses. Tumorigenic strains C5.7 and C6.5 carry nopaline-type Ti plasmids pTiC5.7/pTiC6.5, whereas the nonpathogenic strain Colt5.8 carries the nopaline-type OC plasmid pOC-Colt5.8. Overall, comparative genomic analysis indicated that pTiC5.7/pTiC6.5 and related Ti plasmids described before (pTiC58 and pTi-SAKURA) originate from a common ancestor, although they have diverged during evolution. On the other hand, plasmid pOC-Colt5.8 was most closely related to the well-known OC plasmid pAtK84b; however, analysis suggested that they had different evolutionary histories and seem to share a more distant common ancestor. Although the reconstruction of the evolutionary history of Ti and OC plasmids is still speculative, we hypothesized that nopaline-type Ti plasmid might originate from the nopaline-type OC plasmid. Our results suggested that OC plasmids are widespread and closely associated with crown gall tumors. Finally, we proposed a thorough scheme for classification of Ti and OC plasmids that is based on separate comparative analysis of each functional element of the plasmid studied.
Topics: Arginine; Conjugation, Genetic; Oxazines; Plant Tumors; Plasmids; Rhizobium; Virulence
PubMed: 31028704
DOI: 10.1093/gbe/evz091 -
The New Phytologist Apr 2018Gibberellin (GA) regulates various plant growth and developmental processes, but its role in pathogen attack, and especially nematode-plant interactions, still remains...
Gibberellin (GA) regulates various plant growth and developmental processes, but its role in pathogen attack, and especially nematode-plant interactions, still remains to be elucidated. An in-depth characterization of the role of GA in nematode infection was conducted using mutant lines of rice, chemical inhibitors, and phytohormone measurements. Our results showed that GA influences rice-Meloidogyne graminicola interactions in a concentration-dependent manner. Foliar spray of plants with a low concentration of gibberellic acid enhanced nematode infection. Biosynthetic and signaling mutants confirmed the importance of gibberellin for rice susceptibility to M. graminicola infection. Our study also demonstrates that GA signaling suppresses jasmonate (JA)-mediated defense against M. graminicola, and likewise the JA-induced defense against M. graminicola requires SLENDER RICE1 (SLR1)-mediated repression of the GA pathway. In contrast to observations from other plant-pathogen interactions, GA plays a dominant role over JA in determining susceptibility to M. graminicola in rice. This GA-induced nematode susceptibility was largely independent of auxin biosynthesis, but relied on auxin transport. In conclusion, we showed that GA-JA antagonistic crosstalk is at the forefront of the interaction between rice and M. graminicola, and SLR1 plays a central role in the JA-mediated defense response in rice against this nematode.
Topics: Animals; Biological Transport; Cyclopentanes; Disease Susceptibility; Gibberellins; Indoleacetic Acids; Models, Biological; Oryza; Oxylipins; Plant Diseases; Plant Growth Regulators; Plant Leaves; Plant Proteins; Plant Shoots; Plant Tumors; Tylenchoidea
PubMed: 29464725
DOI: 10.1111/nph.15046 -
Phytopathology Jun 2017The increased incidence of the crown gall disease caused by Agrobacterium tumefaciens has long been associated with activities of root-knot nematodes (Meloidogyne spp.)....
The increased incidence of the crown gall disease caused by Agrobacterium tumefaciens has long been associated with activities of root-knot nematodes (Meloidogyne spp.). Pot experiments on tomato were designed to assess plant vitality, nematode reproduction, and crown gall incidence in combined infection with Agrobacterium and Meloidogyne spp. on tomato roots. Results suggest that tomato plants infected with pathogenic A. tumefaciens 2 days before the nematodes show enhanced plant defense against M. ethiopica resulting in lower egg and gall counts on roots 45 and 90 days postinoculation (dpi); no significantly enhanced defense was observed when the plant was inoculated with bacteria and nematodes at the same time. Split-root experiments also showed that the observed interaction was systemic. Reverse-transcription quantitative polymerase chain reaction analysis that targeted several genes under plant hormonal control suggests that the suppression was mediated via systemic acquired resistance by the pathogenesis-related protein 1 and that M. ethiopica did not enhance the defense reaction of tomato against Agrobacterium spp. Nematodes completely inhibited tumor growth in a 45-day experiment if inoculated onto the roots before the pathogenic bacteria. We conclude that the observed antagonism in the tested pathosystem was the result of initially strong plant defense that was later suppressed by the invading pathogen and pest.
Topics: Agrobacterium tumefaciens; Animals; Gene Expression Regulation, Plant; Host-Pathogen Interactions; Solanum lycopersicum; Pest Control, Biological; Plant Diseases; Plant Immunity; Plant Proteins; Plant Roots; Plant Tumors; Reproduction; Reverse Transcriptase Polymerase Chain Reaction; Tylenchoidea
PubMed: 28134593
DOI: 10.1094/PHYTO-07-16-0269-R -
Plant Physiology Apr 1995Agrobacterium tumefaciens is the causative agent of crown gall, a disease of dicotyledonous plants characterized by a tumorous phenotype. Earlier in this century,... (Review)
Review
Agrobacterium tumefaciens is the causative agent of crown gall, a disease of dicotyledonous plants characterized by a tumorous phenotype. Earlier in this century, scientific interest in A. tumefaciens was based on the possibility that the study of plant tumors might reveal mechanisms that were also operating in animal neoplasia. In the recent past, the tumorous growth was shown to result from the expression of genes coded for by a DNA segment of bacterial origin that was transferred and became stably integrated into the plant genome. This initial molecular characterization of the infection process suggested that Agrobacterium might be used to deliver genetic material into plants. The potential to genetically engineer plants generated renewed interest in the study of A. tumefaciens. In this review, we concentrate on the most recent advances in the study of Agrobacterium-mediated gene transfer, its relationship to conjugation, DNA processing and transport, and nuclear targeting. In the following discussion, references for earlier work can be found in more comprehensive reviews (Hooykaas and Schilperoort, 1992; Zambryski, 1992; Hooykaas and Beijersbergen, 1994).
Topics: Agrobacterium tumefaciens; Base Sequence; Cell Nucleus; Conjugation, Genetic; DNA, Bacterial; DNA, Single-Stranded; Gene Transfer Techniques; Molecular Sequence Data; Plant Tumors; Plants
PubMed: 7770515
DOI: 10.1104/pp.107.4.1041 -
Molecular Plant-microbe Interactions :... Jan 2007Genetic transformation of plant cells by Agrobacterium tumefaciens represents a unique case of trans-kingdom sex requiring the involvement of both bacterial virulence...
Genetic transformation of plant cells by Agrobacterium tumefaciens represents a unique case of trans-kingdom sex requiring the involvement of both bacterial virulence proteins and plant-encoded proteins. We have developed in planta and leaf-disk assays in Nicotiana benthamiana for identifying plant genes involved in Agrobacterium-mediated plant transformation using virus-induced gene silencing (VIGS) as a genomics tool. VIGS was used to validate the role of several genes that are either known or speculated to be involved in Agrobacterium-mediated plant transformation. We showed the involvement of a nodulin-like protein and an alpha-expansin protein (alpha-Exp) during Agrobacterium infection. Our data suggest that alpha-Exp is involved during early events of Agrobacterium-mediated transformation but not required for attaching A. tumefaciens. By employing the combination of the VIGS-mediated forward genetics approach and an in planta tumorigenesis assay, we identified 21 ACG (altered crown gall) genes that, when silenced, produced altered crown gall phenotypes upon infection with a tumorigenic strain of A. tumefaciens. One of the plant genes identified from the screening, Histone H3 (H3), was further characterized for its biological role in Agrobacterium-mediated plant transformation. We provide evidence for the role of H3 in transfer DNA integration. The data presented here suggest that the VIGS-based approach to identify and characterize plant genes involved in genetic transformation of plant cells by A. tumefaciens is simple, rapid, and robust and complements other currently used approaches.
Topics: Agrobacterium tumefaciens; Gene Expression Regulation, Plant; Gene Silencing; Genes, Plant; Histones; Membrane Proteins; Plant Leaves; Plant Proteins; Plant Tumors; Nicotiana; Transformation, Genetic
PubMed: 17249421
DOI: 10.1094/MPMI-20-0041 -
Scientific Reports Jun 2021Insect-induced galls are microhabitats distinct from the outer environment that support inhabitants by providing improved nutrients, defence against enemies, and other...
Insect-induced galls are microhabitats distinct from the outer environment that support inhabitants by providing improved nutrients, defence against enemies, and other unique features. It is intriguing as to how insects reprogram and modify plant morphogenesis. Because most of the gall systems are formed on trees, it is difficult to maintain them in laboratories and to comprehend the mechanisms operative in them through experimental manipulations. Herein, we propose a new model insect, Smicronyx madaranus, for studying the mechanisms of gall formation. This weevil forms spherical galls on the shoots of Cuscuta campestris, an obligate parasitic plant. We established a stable system for breeding and maintaining this ecologically intriguing insect in the laboratory, and succeeded in detailed analyses of the gall-forming behaviour, gall formation process, and histochemical and physiological features. Parasitic C. campestris depends on host plants for its nutrients, and usually shows low chlorophyll content and photosynthetic activity. We demonstrate that S. madaranus-induced galls have significantly increased CO absorbance. Moreover, chloroplasts and starch accumulated in gall tissues at locations inhabited by the weevil larvae. These results suggest that the gall-inducing weevils enhance the photosynthetic activity in C. campestris, and modify the plant tissue to a nutrient-rich shelter for them.
Topics: Animals; Chlorophyll; Disease Susceptibility; Host-Parasite Interactions; Insecta; Phenotype; Photosynthesis; Plant Tumors; Plants
PubMed: 34155293
DOI: 10.1038/s41598-021-92417-3 -
Scientific Reports Mar 2019The galls induced by Schlechtendaia chinensis, Schlechtendaia peitan and Nurudea shiraii on Rhus chinensis and gall induced by Kaburagia rhusicola rhusicola on Rhus...
The galls induced by Schlechtendaia chinensis, Schlechtendaia peitan and Nurudea shiraii on Rhus chinensis and gall induced by Kaburagia rhusicola rhusicola on Rhus potaninii Maxim. are the largest plant galls and have great economic and medical values. We examined the structures of galls and their functional adaptation using various macro- and microscopic techniques. The highly adapted structures include a stalk at the base that is specialized for mechanical support and transport of nutrients for aphids, and a network of vascular bundles which accompanying schizogenous ducts arranged in a way to best support aphid feeding and population growth. There are many circular and semicircular xylems traces in an ensiform gall in cross sectional views, which would provide more nutrition and occupy less space. We infer the evolution trail was flower-like gall, horned gall, circular gall and ensiform gall. And the possible evolutionary trend of the gall was bigger chamber, more stable mechanical supporting, easier for exchanging substance and transporting nutrients.
Topics: Adaptation, Physiological; Animals; Aphids; Biological Evolution; Host-Parasite Interactions; Image Processing, Computer-Assisted; Plant Tumors; Rhus
PubMed: 30914739
DOI: 10.1038/s41598-019-41656-6 -
Plant Physiology Jan 2001
Topics: Bacteriology; DNA, Bacterial; History, 20th Century; Plant Tumors; Plasmids; Rhizobium
PubMed: 11154285
DOI: 10.1104/pp.125.1.9 -
Molecular Plant-microbe Interactions :... Mar 2017In this review, the wisdom and efficacy of studies seeking disease attenuating microbes and microbiomes only in healthy plant communities is questioned and an... (Review)
Review
In this review, the wisdom and efficacy of studies seeking disease attenuating microbes and microbiomes only in healthy plant communities is questioned and an alternative view is posited, namely that success in biocontrol of crop diseases may also come from studies of microbiota, or at least individual species isolates, associated with diseased plants. In support of this view, I summarize the current extensive knowledge of the biology behind what is probably the most successful biocontrol of a plant disease, namely the biocontrol of crown gall of stone fruit using non-pathogenic Rhizobium rhizogenes K84, in which the biocontrol agent itself came from a diseased plant.
Topics: Biological Control Agents; Microbiota; Plant Diseases; Plant Tumors; Plants
PubMed: 28051350
DOI: 10.1094/MPMI-12-16-0252-CR