scholarly journals Glycine addition improves feeding performance of non-specialist herbivores on the privet, Ligustrum obtusifolium: In vivo evidence for the physiological impacts of anti-nutritive plant defense with iridoid and insect adaptation with glycine

2009 ◽  
Vol 44 (4) ◽  
pp. 595-601 ◽  
Author(s):  
Kotaro Konno ◽  
Chikara Hirayama ◽  
Hiroshi Shinbo ◽  
Masatoshi Nakamura
Keyword(s):  
Plant Defense ◽  
Feeding Performance ◽  
Specialist Herbivores

scholarly journals Interactive effect matters: a combination of herbivory degree and the ratio of generalist to specialist better predicts evolution of plant defense

2022 ◽  
Author(s):  
Yuanfei Pan ◽  
Xiaoyun Pan ◽  
Lucas Del Bianco Faria ◽  
Bo Li
Keyword(s):  
Plant Defense ◽  
Invasive Plants ◽  
Interactive Effect ◽  
Cost Benefit ◽  
Generalist Herbivore ◽  
Theoretical Context ◽  
Theoretical Support ◽  
Specialist Herbivores ◽  
Latitudinal Patterns

Herbivory degree and the ratio of generalist to specialist herbivores have long been treated as two important but independent factors in shaping the evolution of plant defense. However, this assumption of independency is poorly supported and has resulted in great controversy in explaining the patterns of plant defense. Here we investigated the possible interaction between herbivory degree and generalist-to-specialist ratio using a cost-benefit model of defense evolution in plants. Our results showed that, with increasing generalist herbivore proportion, plant defense investment increases when herbivory degree is low and decreases when herbivory degree is high. These results provide the first theoretical support for the interactive effect of herbivory degree and ratio of generalist/specialist affecting plant defense, which integrate many of the previous results (e.g. latitudinal patterns of plant defense and defense evolution of invasive plants) and put them into a more general theoretical context.

scholarly journals Role of Saponins in Plant Defense Against Specialist Herbivores

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2067 ◽  
Author(s):  
Mubasher Hussain ◽  
Biswojit Debnath ◽  
Muhammad Qasim ◽  
Bamisope Steve Bamisile ◽  
Waqar Islam ◽  
...  
Keyword(s):  
Plant Defense ◽  
Host Plant ◽  
Larval Survival ◽  
Bioactive Molecules ◽  
Plant Metabolites ◽  
Specialist Herbivore ◽  
Triterpenoid Saponins ◽  
Secondary Plant Metabolites ◽  
Specialist Herbivores

The diamondback moth (DBM), Plutella xylostella (Lepidoptera: Plutellidae) is a very destructive crucifer-specialized pest that has resulted in significant crop losses worldwide. DBM is well attracted to glucosinolates (which act as fingerprints and essential for herbivores in host plant recognition) containing crucifers such as wintercress, Barbarea vulgaris (Brassicaceae) despite poor larval survival on it due to high-to-low concentration of saponins and generally to other plants in the genus Barbarea. B. vulgaris build up resistance against DBM and other herbivorous insects using glucosinulates which are used in plant defense. Aside glucosinolates, Barbarea genus also contains triterpenoid saponins, which are toxic to insects and act as feeding deterrents for plant specialist herbivores (such as DBM). Previous studies have found interesting relationship between the host plant and secondary metabolite contents, which indicate that attraction or resistance to specialist herbivore DBM, is due to higher concentrations of glucosinolates and saponins in younger leaves in contrast to the older leaves of Barbarea genus. As a response to this phenomenon, herbivores as DBM has developed a strategy of defense against these plant biochemicals. Because there is a lack of full knowledge in understanding bioactive molecules (such as saponins) role in plant defense against plant herbivores. Thus, in this review, we discuss the role of secondary plant metabolites in plant defense mechanisms against the specialist herbivores. In the future, trials by plant breeders could aim at transferring these bioactive molecules against herbivore to cash crops.

scholarly journals AtWRKY75 positively regulates jasmonate-mediated plant defense to necrotrophic fungal pathogens

2020 ◽  
Author(s):  
Ligang Chen ◽  
Liping Zhang ◽  
Shengyuan Xiang ◽  
Yanli Chen ◽  
Haiyan Zhang ◽  
...  
Keyword(s):  
Plant Defense ◽  
Signaling Pathway ◽  
Defense Response ◽  
Fungal Pathogens ◽  
Defense Responses ◽  
Alternaria Brassicicola ◽  
Pcr Analysis ◽  
Agronomic Crops

Abstract Necrotrophic fungi cause devastating diseases in both horticultural and agronomic crops, but our understanding of plant defense responses against these pathogens is still limited. In this study, we demonstrated that AtWRKY75 positively regulates the jasmonate (JA)-mediated plant defense against necrotrophic fungal pathogens Botrytis cinerea and Alternaria brassicicola and also affects plants’ sensitivity to JA-inhibited seed germination and root growth. Quantitative RT-PCR analysis indicated that the expression of several JA-associated genes, such as ORA59 and PDF1.2, was significantly reduced in wrky75 mutants and significantly enhanced in 35S:WRKY75 transgenic plants. Immunoprecipitation assays revealed that WRKY75 directly binds to ORA59 promoters and represses its transcription. In vivo and in vitro experiments suggested that WRKY75 interacts with several JASMONATE ZIM-domain proteins, which are repressors of the JA signaling pathway. We determined that JAZ8 represses the transcriptional function of WRKY75, thereby attenuating the expression of its regulon. Consistent with this finding, overexpression of JAZ8 repressed plant defense response to B. cinerea. Taken together, our study provides evidence that WRKY75 functions as a critical component of the JA-mediated signaling pathway to positively regulate Arabidopsis defense response to necrotrophic pathogens.

Fine Structural Changes in the Microvasculature of the Mouse Pinna: Aging and Radiation Injury

1974 ◽  
Vol 32 ◽  
pp. 54-55
Author(s):  
S. Phyllis Steamer ◽  
Rosemarie L. Devine
Keyword(s):  
Structural Changes ◽  
Radiation Treatment ◽  
Arterial Stenosis ◽  
Ultrastructural Changes ◽  
Vascular Effects ◽  
Microvascular Changes ◽  
Surrounding Connective Tissue ◽  
Fission Neutrons ◽  
Total Body

The importance of radiation damage to the skin and its vasculature was recognized by the early radiologists. In more recent studies, vascular effects were shown to involve the endothelium as well as the surrounding connective tissue. Microvascular changes in the mouse pinna were studied in vivo and recorded photographically over a period of 12-18 months. Radiation treatment at 110 days of age was total body exposure to either 240 rad fission neutrons or 855 rad 60Co gamma rays. After in vivo observations in control and irradiated mice, animals were sacrificed for examination of changes in vascular fine structure. Vessels were selected from regions of specific interest that had been identified on photomicrographs. Prominent ultrastructural changes can be attributed to aging as well as to radiation treatment. Of principal concern were determinations of ultrastructural changes associated with venous dilatations, segmental arterial stenosis and tortuosities of both veins and arteries, effects that had been identified on the basis of light microscopic observations. Tortuosities and irregularly dilated vein segments were related to both aging and radiation changes but arterial stenosis was observed only in irradiated animals.

Induction and Differentiation of Dental Epithelium in Vivo and in Vitro

1982 ◽  
Vol 40 ◽  
pp. 142-145
Author(s):  
E. J. Kollar
Keyword(s):  
Connective Tissue ◽  
Oral Mucosa ◽  
Basal Lamina ◽  
Functional Derivatives ◽  
Specific Source ◽  
Dental Epithelium ◽  
Connective Tissue Stroma

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.

Ultrastructural Correlations between Clonal Human Tumor Colonies and in Vivo Neoplasms

1982 ◽  
Vol 40 ◽  
pp. 210-211
Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman
Keyword(s):  
Cultured Cells ◽  
Human Tumor ◽  
Cell Type ◽  
Tumor Mass ◽  
Initial Cell ◽  
Cloning Assay ◽  
Human Tumor Cloning ◽  
The Relationship

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.

Structural analysis of the photosynthetic membrane from Ectothiorhodospira halochloris

1983 ◽  
Vol 41 ◽  
pp. 740-741
Author(s):  
H. Engelhardt ◽  
R. Guckenberger ◽  
W. Baumeister
Keyword(s):  
Lattice Structure ◽  
Bacterial Species ◽  
Hexagonal Lattice ◽  
Reaction Centre ◽  
Photosynthetic Membrane ◽  
Rhodopseudomonas Viridis ◽  
Photosynthetic Membranes ◽  
Ectothiorhodospira Halochloris ◽  
Main Components

Bacterial photosynthetic membranes contain, apart from lipids and electron transport components, reaction centre (RC) and light harvesting (LH) polypeptides as the main components. The RC-LH complexes in Rhodopseudomonas viridis membranes are known since quite seme time to form a hexagonal lattice structure in vivo; hence this membrane attracted the particular attention of electron microscopists. Contrary to previous claims in the literature we found, however, that 2-D periodically organized photosynthetic membranes are not a unique feature of Rhodopseudomonas viridis. At least five bacterial species, all bacteriophyll b - containing, possess membranes with the RC-LH complexes regularly arrayed. All these membranes appear to have a similar lattice structure and fine-morphology. The lattice spacings of the Ectothiorhodospira haloohloris, Ectothiorhodospira abdelmalekii and Rhodopseudomonas viridis membranes are close to 13 nm, those of Thiocapsa pfennigii and Rhodopseudomonas sulfoviridis are slightly smaller (∼12.5 nm).

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