Different polyphenolic parenchyma cell and phloem axial resin duct-like structures formation rates in Cupressus sempervirens clones infected with Seiridium cardinale

The aim of this study was the characterization of constitutive and induced defence mechanisms in the bark tissues of Cupressus sempervirens before and after infection with the bark fungus Seiridium cardinale that is responsible for Cypress Canker Disease. The time-course development of polyphenolic parenchyma cells (PP cells) and phloem axial resin ducts PARDs(PARD) like structures) in the phloem was investigated in two C. sempervirens clones, one resistant and one susceptible to the disease, through anatomycal and hystologycal observations carried out by light microscope during a 19 days trial. PP cells were constitutively more abundant in the canker resistant clone compared to the susceptible clone, while PARDsPARD-like structures were not present in the bark of untreated plants of both clones. PP cells increased in both clones as a response to infection, but in the resistant clone they were more abundant 5 and 12 days after inoculation. Following inoculation, PARDsPARD-like structures appeared in the phloem after 5 days in the resistant clone and only after 12 days in the susceptible clone. Even the number of secretory cells (surrounding the PARDsPARD-like structures) was higher in the R clone 5 and 12 days after inoculation compared to the S clone. These observations demonstrate a faster phloem response of the resistant clone in the early phase of the infection. This may slow down initial growth of the fungus contributing to the resistance mechanism.

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In vitro activities of novel catecholate siderophores against Plasmodium falciparum.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.40.9.2094 ◽

1996 ◽

Vol 40 (9) ◽

pp. 2094-2098 ◽

Cited By ~ 13

Author(s):

B Pradines ◽

F Ramiandrasoa ◽

L K Basco ◽

L Bricard ◽

G Kunesch ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Mechanism Of Action ◽

Ribonucleotide Reductase ◽

Antimalarial Activity ◽

Iron Chelators ◽

Resistant Clone ◽

Iron Deprivation ◽

Level Of Activity ◽

Susceptible Clone

The activities of novel iron chelators, alone and in combination with chloroquine, quinine, or artemether, were evaluated in vitro against susceptible and resistant clones of Plasmodium falciparum with a semimicroassay system. N4-nonyl,N1,N8-bis(2,3-dihydroxybenzoyl) spermidine hydrobromide (compound 7) demonstrated the highest level of activity: 170 nM against a chloroquine-susceptible clone and 1 microM against a chloroquine-resistant clone (50% inhibitory concentrations). Compounds 6, 8, and 10 showed antimalarial activity with 50% inhibitory concentrations of about 1 microM. Compound 7 had no effect on the activities of chloroquine, quinine, and artemether against either clone, and compound 8 did not enhance the schizontocidal action of either chloroquine or quinine against the chloroquine-resistant clone. The incubation of compound 7 with FeCI3 suppressed or decreased the in vitro antimalarial activity of compound 7, while no effect was observed with incubation of compound 7 with CuSO4 and ZnSO4. These results suggest that iron deprivation may be the main mechanism of action of compound 7 against the malarial parasites. Chelator compounds 7 and 8 primarily affected trophozoite stages, probably by influencing the activity of ribonucleotide reductase, and thus inhibiting DNA synthesis.

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Influence of tree age and growth rate on the radial resin duct system in loblolly pine (Pinus taeda)

Canadian Journal of Botany ◽

10.1139/b86-142 ◽

1986 ◽

Vol 64 (5) ◽

pp. 1046-1049 ◽

Cited By ~ 16

Author(s):

J. D. DeAngelis ◽

T. E. Nebeker ◽

J. D. Hodges

Keyword(s):

Growth Rate ◽

Pinus Taeda ◽

Loblolly Pine ◽

Dendroctonus Frontalis ◽

Age And Growth ◽

Tree Age ◽

Secretory Cells ◽

Tangential Plane ◽

Cross Sectional ◽

Resin Duct

Formation of radial resin ducts and their associated secretory cells in loblolly pine (Pinus taeda L.) is influenced by the age and growth rate of the annual ring in which the ducts are formed. The spatial pattern of radial ducts on the tangential plane is nonrandom, exhibiting a regular or dispersed pattern. A significantly higher density of radial ducts was found in the inner, first-formed growth rings at all heights within the tree. Radial duct formation was found to be positively correlated with radial growth rate, when growth rate is expressed as increment of cross-sectional area growth. These findings may partially explain why older, slower growing trees tend to be more susceptible to attack by the southern pine beetle, Dendroctonus frontalis Zimmermann, and associated microorganisms, since the resin-producing system is a primary defense against these agents.

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Strong parasitoid-mediated selection in experimental populations of aphids

Biology Letters ◽

10.1098/rsbl.2007.0362 ◽

2007 ◽

Vol 3 (6) ◽

pp. 667-669 ◽

Cited By ~ 31

Author(s):

Jenny Herzog ◽

Christine B Müller ◽

Christoph Vorburger

Keyword(s):

Clonal Diversity ◽

Important Variable ◽

Diaeretiella Rapae ◽

Resistant Clone ◽

Potato Aphid ◽

Aphidius Colemani ◽

Experimental Populations ◽

Asexual Populations ◽

Susceptible Clone ◽

Peach Potato Aphid

Clonal diversity in asexual populations may be maintained if different clones are favoured under different environmental conditions. For aphids, parasitoids are an important variable of the biotic environment. To test whether parasitoids can mediate selection among host clones, we used experimental populations consisting of 10 clones of the peach–potato aphid, Myzus persicae , and allowed them to evolve for several generations either without parasitoids or in the presence of two species of parasitoid wasps. In the absence of parasitoids, strong shifts in clonal frequencies occurred, mostly in favour of clones with high rates of increase. The parasitoid Diaeretiella rapae hardly affected aphid densities but changed the outcome of competition by favouring one entirely resistant clone and disfavouring a highly susceptible clone. Aphidius colemani , the more infective parasitoid, strongly reduced aphid densities and dramatically changed host clonal frequencies. The most resistant clone, not a successful clone without parasitoids, became totally dominant. These results highlight the potential of temporal or spatial variation in parasitoid densities to maintain clonal diversity in their aphid hosts.

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A metabolomics characterisation of natural variation in the resistance of cassava to whitefly

BMC Plant Biology ◽

10.1186/s12870-019-2107-1 ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 4

Author(s):

Laura Perez-Fons ◽

Adriana Bohorquez-Chaux ◽

Maria L. Irigoyen ◽

Danielle C. Garceau ◽

Kris Morreel ◽

...

Keyword(s):

Time Course ◽

Management Strategies ◽

Resistance Mechanism ◽

Central Africa ◽

Susceptible Variety ◽

Induced Response ◽

Genotypic Differences ◽

Germplasm Collections ◽

Resistant Varieties ◽

Quantitative Changes

Abstract Background Cassava whitefly outbreaks were initially reported in East and Central Africa cassava (Manihot esculenta Crantz) growing regions in the 1990’s and have now spread to other geographical locations, becoming a global pest severely affecting farmers and smallholder income. Whiteflies impact plant yield via feeding and vectoring cassava mosaic and brown streak viruses, making roots unsuitable for food or trading. Deployment of virus resistant varieties has had little impact on whitefly populations and therefore development of whitefly resistant varieties is also necessary as part of integrated pest management strategies. Suitable sources of whitefly resistance exist in germplasm collections that require further characterization to facilitate and assist breeding programs. Results In the present work, a hierarchical metabolomics approach has been employed to investigate the underlying biochemical mechanisms associated with whitefly resistance by comparing two naturally occurring accessions of cassava, one susceptible and one resistant to whitefly. Quantitative differences between genotypes detected at pre-infestation stages were consistently observed at each time point throughout the course of the whitefly infestation. This prevalent differential feature suggests that inherent genotypic differences override the response induced by the presence of whitefly and that they are directly linked with the phenotype observed. The most significant quantitative changes relating to whitefly susceptibility were linked to the phenylpropanoid super-pathway and its linked sub-pathways: monolignol, flavonoid and lignan biosynthesis. These findings suggest that the lignification process in the susceptible variety is less active, as the susceptible accession deposits less lignin and accumulates monolignol intermediates and derivatives thereof, differences that are maintained during the time-course of the infestation. Conclusions Resistance mechanism associated to the cassava whitefly-resistant accession ECU72 is an antixenosis strategy based on reinforcement of cell walls. Both resistant and susceptible accessions respond differently to whitefly attack at biochemical level, but the inherent metabolic differences are directly linked to the resistance phenotype rather than an induced response in the plant.

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Protein synthesis in compensatory hypertrophy of rat plantaris

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y84-197 ◽

1984 ◽

Vol 62 (9) ◽

pp. 1178-1182 ◽

Cited By ~ 22

Author(s):

Earl G. Noble ◽

Qian Tang ◽

Paul B. Taylor

Keyword(s):

Protein Synthesis ◽

Time Course ◽

Muscle Protein ◽

Muscle Growth ◽

Compensatory Hypertrophy ◽

Initial Growth ◽

Similar Time ◽

Tissue Mass ◽

Hypertrophic Growth ◽

Tissue Protein Synthesis

Protein synthesis in rat plantaris muscle undergoing surgically induced hypertrophy was studied using a perfused hindquarter preparation. The tissue mass of the hypertrophied muscle increased 11, 33, 33, and 104% at 2, 5, 15, and 50 days postsurgery. Total tissue protein synthesis was unchanged during the early phase but was significantly elevated after 15 and 50 days of work overload. Myosin synthesis was also significantly elevated after 15 and 50 days of hypertrophic growth. Increases in muscle protein content (milligrams per muscle) for each protein fraction examined were temporally in step with the altered synthetic rates. The shift in muscle fibre-type profile from approximately 10% alkaline-labile fibres in the control muscle to about 25% alkaline-labile fibres in the hypertrophied muscle also followed a similar time course. These data suggest that during compensatory hypertrophy, enhanced protein synthesis may be the dominant mechanism for the massive accumulation of muscle protein. However, its contribution to muscle growth does not become evident until about 15 days after the initial growth stimulus.

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Barrier Zone Formation as a Resistance Mechanism of Elms to Dutch Elm Disease

IAWA Journal ◽

10.1163/22941932-90000916 ◽

1985 ◽

Vol 6 (1) ◽

pp. 71-77 ◽

Cited By ~ 19

Author(s):

K.J.M. Bonsen ◽

R.J. Scheffer ◽

D.M. Elgersma

Keyword(s):

Time Course ◽

Resistance Mechanism ◽

Dutch Elm Disease ◽

Host Responses ◽

Moderate Degree ◽

Zone Formation ◽

Ophiostoma Ulmi ◽

Time Course Study ◽

High Degree ◽

Barrier Zone

Host responses of elms susceptible and resistant to Dutch elm disease were histologically examined. In a time course study the susceptible elm clone Ulmus × hollandica 'Belgica' and U. × hollandica '390', a clone which shows a high degree of resistance to non-aggressive isolates and a moderate degree of resistance to aggressive isolates of Ophiostoma ulmi, were inoculated in twig or trunk with either an aggressive or a non-aggressive isolate of O. ulmi. For purposes of comparison, the susceptible elm U. americana and the more resistant clones U. × hollandica 'Groeneveld', U. 'Lobel' and U. 'Sapporo Autumn Gold' were included. Depending on clone-isolate compatibility, infected twigs reacted by a walling off process, by barrier zone formation, or failed to resist the infection and died. Trees inoculated into the trunk reacted comparably but in the case of a compatible combination they always formed a barrier zone and the cambium never died in the year of inoculation.

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`Italico' and `Mediterraneo': Two Seiridium cardinale Canker-Resistant Cypress Cultivars of Cupressus sempervirens

HortScience ◽

10.21273/hortsci.41.5.1357 ◽

2006 ◽

Vol 41 (5) ◽

pp. 1357-1359 ◽

Cited By ~ 17

Author(s):

R. Danti ◽

A. Panconesi ◽

V. Di Lonardo ◽

G. Della Rocca ◽

P. Raddi

Keyword(s):

Essential Oils ◽

L- and T-type voltage-gated Ca2+ currents in adrenal medulla endothelial cells

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1999.276.4.h1313 ◽

1999 ◽

Vol 276 (4) ◽

pp. H1313-H1322 ◽

Cited By ~ 8

Author(s):

Raul Vinet ◽

Fernando F. Vargas

Keyword(s):

Endothelial Cells ◽

Adrenal Medulla ◽

Time Course ◽

Maximum Amplitude ◽

Secretory Cells ◽

Activation Time ◽

Patch Clamp Technique ◽

Activation Threshold ◽

Current Voltage ◽

Voltage Dependent

We investigated voltage-dependent Ca2+ channels of bovine adrenal medulla endothelial cells with the whole cell version of the patch-clamp technique. Depolarization elicited an inward current that was carried by Ca2+ and was composed of a transient (T) current, present in all the cells tested, and a sustained (L) current, present in 65% of them. We separated these currents and measured their individual kinetic and gating properties. The activation threshold for T current was approximately −50 mV, and its maximum amplitude was −49.8 ± 4.8 pA (means ± SE, n = 19) at 0 mV. The time constant was 10.2 ± 1.5 ms ( n= 4) for activation and 18.4 ± 2.8 ms ( n = 4) for inactivation. The L current activated at −40 mV, and it reached a plateau at −20.1 ± 2.3 pA ( n = 6). Its activation time course was a single exponential with an activation time contant of 26.8 ± 2.3 ms ( n = 4). Current-voltage curves, kinetics, gating, response to BAY K 8644, nifedipine, amiloride, and different selectivity for Ba2+ and Ca2+ indicated that the underlying channels for the observed currents are only of the T- and L-types that resemble those of the endocrine secretory cells.

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The Epidemic Spread of Seiridium cardinale on Leyland Cypress Severely Limits Its Use in the Mediterranean

Plant Disease ◽

10.1094/pdis-12-13-1237-re ◽

2014 ◽

Vol 98 (8) ◽

pp. 1081-1087 ◽

Cited By ~ 7

Author(s):

R. Danti ◽

S. Barberini ◽

A. Pecchioli ◽

V. Di Lonardo ◽

G. Della Rocca

Keyword(s):

Central Italy ◽

Cupressus Sempervirens ◽

Trunk Diameter ◽

Fast Growing ◽

Dead Trees ◽

Control Clone ◽

Seiridium Cardinale ◽

Commercially Important ◽

The Mean ◽

The Mediterranean

Leyland cypress (× Hesperotropsis leylandii) is a fast-growing conifer used in most temperate regions as an ornamental tree for hedges and screens, and is one of the most commercially important trees in Europe. In recent years, severe diebacks and mortality due to cypress canker have been observed on Leyland cypress plantations in Southern Europe. This study was conducted to evaluate (i) the spread and impact of cypress canker caused by Seiridium cardinale in plantations of a sample area of 1,250 km2 in central Italy, (ii) the response of the most commonly grown Leyland cypress varieties to artificial inoculation with to S. cardinal, and (iii) the pathogenicity of S. cardinale isolates obtained from Leyland cypress. Of the 1,411 surveyed trees, 11.4% had been killed by cypress canker and 43.9% of the living trees were affected by the disease. The number of diseased or dead trees and the percentage of cankered trunks was significantly correlated with the mean trunk diameter of the plantations. Six months after inoculation, the size of developed cankers was significantly different among the inoculated Leyland cypress cultivars but all of them showed markedly larger cankers than the C. sempervirens canker-resistant control clone. All of the tested S. cardinale isolates obtained from Leyland cypress also caused cankers on Cupressus sempervirens when inoculated as conidial suspensions or mycelia. Leyland cypress is highly prone to contract cypress canker in the Mediterranean due to its high susceptibility to S. cardinale infections, low genetic variability among the grown cultivars, and cracks which form on fast-growing trunks, favoring entry of the fungus into the inner bark and the occurrence of infections.

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Histomorphometric analyses of cancellous bone from COSMOS 2044 rats

Journal of Applied Physiology ◽

10.1152/jappl.1993.75.5.2203 ◽

1993 ◽

Vol 75 (5) ◽

pp. 2203-2208 ◽

Cited By ~ 55

Author(s):

L. Vico ◽

S. Bourrin ◽

C. Genty ◽

S. Palle ◽

C. Alexandre

Keyword(s):

Vertebral Body ◽

Cancellous Bone ◽

Time Course ◽

Physiological Stress ◽

Weight Bearing ◽

Bone Volume ◽

Initial Growth ◽

Turnover Rates ◽

Lumbar Vertebral Body ◽

Male Wistar Rats

The influence of 14 days of spaceflight on cancellous bone of male Wistar rats was assessed by histomorphometric analysis. In proximal tibia, no difference was found between flight, synchronous, vivarium, and basal groups for epiphyseal bone volume or trabecular arrangement. In metaphysis, primary spongiosa width was reduced in flight rats, suggesting an alteration in bone longitudinal growth. In flight rats, secondary spongiosa evidenced a trend toward decreased bone mass, trabecular number and thickness, and osteoid surfaces, whereas there was a tendency toward increased osteoclast number compared with vivarium control but not with synchronous rats. In femoral fossa trochanteri, an area facing deep muscular insertions, no changes in bone volume or structure were noted among the different groups. However, a reduction of osteoid surfaces was seen in flight and synchronous groups compared with the other groups. Resorption activity was increased in flight rats compared with control rats. In thoracic vertebral body, osteoblastic surfaces decreased similarly in flight and synchronous rats. In lumbar vertebral body, decreased osteoblastic surfaces and increased osteoclastic parameters were observed in flight and synchronous rats. The more striking effects of spaceflight were the decrease in tibial primary spongiosa width and the increase in resorption activity of the femoral fossa trochanteri. In all other sites, cellular alterations appeared similar in flight and synchronous rats, suggesting a role for physiological stress. The time course of events would depend on initial growth and turnover rates of bone, its weight-bearing function on earth, and the presence of muscular insertions.

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