scholarly journals Structural, histochemical and photosynthetic profiles of galls induced by Eugeniamyia dispar (Diptera, Cecidomyiidae) on the leaves of Eugenia uniflora (Myrtaceae)

2018 ◽  
Vol 66 (4) ◽  
pp. 1469 ◽  
Author(s):  
Uiara Rezende ◽  
Ana Silvia Moreira ◽  
Vinícius Kuster ◽  
Denis Oliveira
Keyword(s):  
Host Plant ◽  
Structural Changes ◽  
Reducing Sugars ◽  
Photosynthetic Activity ◽  
Gas Diffusion ◽  
Oxygen Species ◽  
Nutritive Tissue ◽  
Eugenia Uniflora ◽  
Plant Organ ◽  
Physiological Profiles

Gall-inducing insects manipulate the structural, histochemical and physiological profiles of host-plant tissues to develop galls. We evaluated galls induced by Eugeniamyia dispar on the leaves of Eugenia uniflora in an attempt to answer the following questions: (i) How does this gall-inducing insect change the structural and histochemical profiles of the host-plant organ? (ii) Despite structural changes, can gall tissues maintain photosynthetic activity? Starch, proteins, reducing sugars and reactive oxygen species were detected mainly in the nutritive tissue surrounding the larval chamber. Despite structural changes, the galls induced by E. dispar on E. uniflora retain chlorophyllous tissue, although its amount and photosynthetic activity are less than that of non-galled leaves. This reduced photosynthetic activity, in association with the presence of large intercellular spaces, could improve gas diffusion and, consequently, avoid hypoxia and hypercarbia in gall tissue. 

scholarly journals Structural and histochemical profile of Lopesia sp. Rübsaamen 1908 pinnula galls on Mimosa tenuiflora (Willd.) Poir. in a Caatinga environment

Hoehnea ◽  
2018 ◽  
Vol 45 (2) ◽  
pp. 314-322 ◽  
Author(s):  
Ravena Malheiros Nogueira ◽  
Elaine Cotrim Costa ◽  
Juliana Santos Silva ◽  
Rosy Mary dos Santos Isaias
Keyword(s):  
Structural Changes ◽  
Reducing Sugars ◽  
Chemical Defence ◽  
Reducing Sugar ◽  
Plant Tissues ◽  
Nutritive Tissue ◽  
Outer Compartment ◽  
Histochemical Tests ◽  
Tissue Compartments ◽  
Mimosa Tenuiflora

ABSTRACT Gall-inducing insects can change the anatomical pattern of host plant tissues by inducing peculiar gall morphotypes. In this study, the structural changes observed in Lopesia galls on Mimosa tenuiflora resemble those found in other Cecidomyiidae, with two tissue compartments. Nevertheless, the parenchyma layers of the inner compartment, between the mechanical zone and the nutritive tissue, are peculiar. Gall development does not impair the synthesis of any compounds detected by histochemical tests on non-galled tissues of M. tenuiflora. Lignin, polyphenols, alkaloids and terpenoids were detected in the outer compartment, suggesting their involvement in chemical defence of galls. Proteins, reducing sugars and lipids were detected both in outer and inner compartments, whereas nutritive tissue is rich in reducing sugar. This profile is linked with the nutrition of the gall-inducing insect. The Caatinga environment does not seem to constrain the development of galls, but the thick periclinal cell wall and homogeneous parenchyma may contribute to the control of humidity and light radiation, thus favouring the survival of the gall-inducing insect.

scholarly journals The Fungal Effector Avr-Pita Suppresses Innate Immunity by Increasing COX Activity in Rice Mitochondria

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jingluan Han ◽  
Xiaoyu Wang ◽  
Fengpin Wang ◽  
Zhe Zhao ◽  
Gousi Li ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Host Plant ◽  
Fungal Pathogen ◽  
Defense Responses ◽  
Oxygen Species ◽  
Mitochondrial Reactive Oxygen Species ◽  
Molecular Pattern ◽  
Ros Accumulation ◽  
Ros Metabolism ◽  
Increased Susceptibility

Abstract Background Avr-Pita was the first effector identified in the blast fungus (Magnaporthe oryzae)–rice (Oryza sativa) pathosystem. However, the molecular mechanism underlying its effects on the host plant has remained a long-standing mystery. Results Here, we report that ectopically expressing Avr-Pita in rice enhances susceptibility to M. oryzae and suppresses pathogen-associated molecular pattern (PAMP)-triggered defense responses. Avr-Pita targets the host mitochondria and interacts with the cytochrome c oxidase (COX) assembly protein OsCOX11, a key regulator of mitochondrial reactive oxygen species (ROS) metabolism in rice. Overexpressing Avr-Pita or OsCOX11 increased COX activity and decreased ROS accumulation triggered by the fungal PAMP chitin. OsCOX11-overexpressing plants showed increased susceptibility to M. oryzae, whereas OsCOX11-knockdown plants showed resistance to M. oryzae. Conclusions Taken together, these findings suggest that the fungal pathogen M. oryzae delivers the effector Avr-Pita to the host plant, where it enhances COX activity thus decreasing ROS accumulation. Therefore, this effector suppresses host innate immunity by perturbing ROS metabolism in the mitochondria.

scholarly journals Matrix Discriminant Analysis Evidenced Surface-Lithium as an Important Factor to Increase the Hydrolytic Saccharification of Sugarcane Bagasse

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3614
Author(s):  
Ana Sílvia de Almeida Scarcella ◽  
Alexandre Favarin Somera ◽  
Christiane da Costa Carreira Nunes ◽  
Eleni Gomes ◽  
Ana Claudia Vici ◽  
...  
Keyword(s):  
Steam Explosion ◽  
Structural Changes ◽  
Reducing Sugars ◽  
Periodic Structures ◽  
Relative Concentration ◽  
Ionic Composition ◽  
Distribution Patterns ◽  
Sugar Cane Bagasse ◽  
Ionic Distribution ◽  
Saccharification Yield

Statistical evidence pointing to the very soft change in the ionic composition on the surface of the sugar cane bagasse is crucial to improve yields of sugars by hydrolytic saccharification. Removal of Li+ by pretreatments exposing -OH sites was the most important factor related to the increase of saccharification yields using enzyme cocktails. Steam Explosion and Microwave:H2SO4 pretreatments produced unrelated structural changes, but similar ionic distribution patterns. Both increased the saccharification yield 1.74-fold. NaOH produced structural changes related to Steam Explosion, but released surface-bounded Li+ obtaining 2.04-fold more reducing sugars than the control. In turn, the higher amounts in relative concentration and periodic structures of Li+ on the surface observed in the control or after the pretreatment with Ethanol:DMSO:Ammonium Oxalate, blocked -OH and O− available for ionic sputtering. These changes correlated to 1.90-fold decrease in saccharification yields. Li+ was an activator in solution, but its presence and distribution pattern on the substrate was prejudicial to the saccharification. Apparently, it acts as a phase-dependent modulator of enzyme activity. Therefore, no correlations were found between structural changes and the efficiency of the enzymatic cocktail used. However, there were correlations between the Li+ distribution patterns and the enzymatic activities that should to be shown.

Spermidine supplementation and voluntary activity differentially affect obesity-related structural changes in the mouse lung

2020 ◽  
Vol 319 (2) ◽  
pp. L312-L324 ◽  
Author(s):  
Nancy Ahrendt ◽  
Tobias Steingrüber ◽  
Alexandra Rajces ◽  
Elena Lopez-Rodriguez ◽  
Tobias Eisenberg ◽  
...  
Keyword(s):  
Physical Activity ◽  
Surface Area ◽  
Structural Changes ◽  
Control Diet ◽  
Gas Diffusion ◽  
Lung Mechanics ◽  
Mouse Lung ◽  
Voluntary Activity ◽  
Lung Volumes ◽  
Endothelial Surface

Obesity is associated with lung function impairment and respiratory diseases; however, the underlying pathophysiological mechanisms are still elusive, and therapeutic options are limited. This study examined the effects of prolonged excess fat intake on lung mechanics and microstructure and tested spermidine supplementation and physical activity as intervention strategies. C57BL/6N mice fed control diet (10% fat) or high-fat diet (HFD; 60% fat) were left untreated or were supplemented with 3 mM spermidine, had access to running wheels for voluntary activity, or a combination of both. After 30 wk, lung mechanics was assessed, and left lungs were analyzed by design-based stereology. HFD exerted minor effects on lung mechanics and resulted in higher body weight and elevated lung, air, and septal volumes. The number of alveoli was higher in HFD-fed animals. This was accompanied by an increase in epithelial, but not endothelial, surface area. Moreover, air-blood barrier and endothelium were significantly thicker. Neither treatment affected HFD-related body weights. Spermidine lowered lung volumes as well as endothelial and air-blood barrier thicknesses toward control levels and substantially increased the endothelial surface area under HFD. Activity resulted in decreased volumes of lung, septa, and septal compartments but did not affect vascular changes in HFD-fed mice. The combination treatment showed no additive effect. In conclusion, excess fat consumption induced alveolar capillary remodeling indicative of impaired perfusion and gas diffusion. Spermidine alleviated obesity-related endothelial alterations, indicating a beneficial effect, whereas physical activity reduced lung volumes apparently by other, possibly systemic effects.

scholarly journals Interaction of Oxidative Stress and Misfolded Proteins in the Mechanism of Neurodegeneration

Life ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 101 ◽  
Author(s):  
Andrey Y. Abramov ◽  
Elena V. Potapova ◽  
Viktor V. Dremin ◽  
Andrey V. Dunaev
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Free Radicals ◽  
Neurodegenerative Disorders ◽  
Structural Changes ◽  
Wide Spectrum ◽  
Physiological Role ◽  
Reactive Oxygen ◽  
Misfolded Proteins ◽  
Oxygen Species

Aggregation of the misfolded proteins β-amyloid, tau, huntingtin, and α-synuclein is one of the most important steps in the pathology underlying a wide spectrum of neurodegenerative disorders, including the two most common ones—Alzheimer’s and Parkinson’s disease. Activity and toxicity of these proteins depends on the stage and form of aggregates. Excessive production of free radicals, including reactive oxygen species which lead to oxidative stress, is proven to be involved in the mechanism of pathology in most of neurodegenerative disorders. Both reactive oxygen species and misfolded proteins play a physiological role in the brain, and only deregulation in redox state and aggregation of the proteins leads to pathology. Here, we review the role of misfolded proteins in the activation of ROS production from various sources in neurons and glia. We discuss if free radicals can influence structural changes of the key toxic intermediates and describe the putative mechanisms by which oxidative stress and oligomers may cause neuronal death.

scholarly journals Insect galls of the xeric vegetation of Ilha do Cabo Frio (Arraial do Cabo, RJ, Brazil)

2013 ◽  
Vol 13 (3) ◽  
pp. 278-288 ◽  
Author(s):  
Valéria Cid Maia ◽  
Marcelo da Costa Souza
Keyword(s):  
Host Plant ◽  
Plant Species ◽  
Field Work ◽  
Insect Galls ◽  
Gall Midges ◽  
Plant Organ ◽  
Plant Families ◽  
Galling Insects ◽  
First Time ◽  
Cabo Frio

The xeric vegetation of Ilha do Cabo Frio (Arraial do Cabo, RJ) was investigated for insect galls, in May, June and August of 2012, totalizing 24 hours of field work. Forty-five morphotypes of insect galls were found on 29 species of host plant (25 genera and 18 families). Asteraceae and Myrtaceae were the most galled plant families. Leaves were the most galled plant organ, with ca. 62% of the total, followed by stems (ca. 22%). Globoid and fusiform galls were the most frequent with about 29% and 24%, respectively. The majority was glabrous (ca. 91%), and one-chambered (ca. 84%). Gallers of 30 morphotypes were determined. They belong to Diptera (Cecidomyiidae), and Lepidoptera. The former was the most frequent. Larvae of Muscomorpha (Diptera) (probably inquilines) were found in a single gall morphotype; parasitoids (Hymenoptera) in seven (ca. 15% of the total), and predators (pseudoscorpion) in a single one. As there is no previous data of insect galls of Ilha do Cabo Frio, all records presented here are new. The geographic distribution of nine species of gall midges (Diptera, Cecidomyiidae) is widened. For the first time, eleven plant species are recorded as host of galling insects, and 24 gall morphotypes are described.

Viscosity and voluminosity of caseins chemically modified by reductive alkylation with reducing sugars

1988 ◽  
Vol 55 (4) ◽  
pp. 539-546 ◽  
Author(s):  
Bernard Colas ◽  
Christine Gobin ◽  
Denis Lorient
Keyword(s):  
Steric Hindrance ◽  
Structural Changes ◽  
Reducing Sugars ◽  
Negative Charge ◽  
Covalent Binding ◽  
Rheological Parameters ◽  
Flow Properties ◽  
Chemical Modifications ◽  
Chemically Modified ◽  
High Concentrations

SummaryThe effect of the covalent binding of reducing sugars such as galactose, glucose, fructose, lactose and maltose on the flow properties of casein solutions and on the voluminosity of casein molecules was investigated, voluminosity being calculated from viscosity measurements. Rheological parameters appeared to be efficient indices of structural changes occurring in proteins as a result of chemical modifications. Results showed an increase in voluminosity of casein after the binding of sugars, possibly explained by an increase in the net negative charge or by an increase in the steric hindrance of the molecule. At high concentrations (above 0·03 g/ml), viscosity of the solutions depended on the nature of the attached sugar and on the level of the modification. Thus galactose- and glucose-modified caseins were more viscous than the control. With disaccharides, the level of modification appeared to be more important than the amount of sugar bound.

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