Localization of calcitonin receptor-like receptor and receptor activity modifying protein 1 in enteric neurons, dorsal root ganglia, and the spinal cord of the rat

Calcitonin receptor-like receptor (CLR) and receptor activity modifying protein 1 (RAMP1) comprise a receptor for calcitonin gene related peptide (CGRP) and intermedin. Although CGRP is widely expressed in the nervous system, less is known about the localization of CLR and RAMP1. To localize these proteins, we raised antibodies to CLR and RAMP1. Antibodies specifically interacted with CLR and RAMP1 in HEK cells coexpressing rat CLR and RAMP1, determined by Western blotting and immunofluorescence. Fluorescent CGRP specifically bound to the surface of these cells and CGRP, CLR, and RAMP1 internalized into the same endosomes. CLR was prominently localized in nerve fibers of the myenteric and submucosal plexuses, muscularis externa and lamina propria of the gastrointestinal tract, and in the dorsal horn of the spinal cord of rats. CLR was detected at low levels in the soma of enteric, dorsal root ganglia (DRG), and spinal neurons. RAMP1 was also localized to enteric and DRG neurons and the dorsal horn. CLR and RAMP1 were detected in perivascular nerves and arterial smooth muscle. Nerve fibers containing CGRP and intermedin were closely associated with CLR fibers in the gastrointestinal tract and dorsal horn, and CGRP and CLR colocalized in DRG neurons. Thus, CLR and RAMP1 may mediate the effects of CGRP and intermedin in the nervous system. However, mRNA encoding RAMP2 and RAMP3 was also detected in the gastrointestinal tract, DRG, and dorsal horn, suggesting that CLR may associate with other RAMPs in these tissues to form a receptor for additional peptides such as adrenomedullin.

Protease-activated receptor 2 mediates eosinophil infiltration and hyperreactivity in allergic inflammation of the airway

Trypsin and mast cell tryptase can signal to epithelial cells, myocytes, and nerve fibers of the respiratory tract by cleaving proteinase-activated receptor 2 (PAR2). Since tryptase inhibitors are under development to treat asthma, a precise understanding of the contribution of PAR2 to airway inflammation is required. We examined the role of PAR2 in allergic inflammation of the airway by comparing OVA-sensitized and -challenged mice lacking or overexpressing PAR2. In wild-type mice, immunoreactive PAR2 was detected in airway epithelial cells and myocytes, and intranasal administration of a PAR2 agonist stimulated macrophage infiltration into bronchoalveolar lavage fluid. OVA challenge of immunized wild-type mice stimulated infiltration of leukocytes into bronchoalveolar lavage and induced airway hyperreactivity to inhaled methacholine. Compared with wild-type animals, eosinophil infiltration was inhibited by 73% in mice lacking PAR2 and increased by 88% in mice overexpressing PAR2. Similarly, compared with wild-type animals, airway hyperreactivity to inhaled methacholine (40 micro g/ml) was diminished 38% in mice lacking PAR2 and increased by 52% in mice overexpressing PAR2. PAR2 deletion also reduced IgE levels to OVA sensitization by 4-fold compared with those of wild-type animals. Thus, PAR2 contributes to the development of immunity and to allergic inflammation of the airway. Our results support the proposal that tryptase inhibitors and PAR2 antagonists may be useful therapies for inflammatory airway disease.

A model for the evolution of pathogen-induced leaf shedding

A size-structured plant population model is developed to study the evolution of pathogen-induced leaf shedding under various environmental conditions. The evolutionary stable strategy (ESS) of the leaf shedding rate is determined for two scenarios: i) a constant leaf shedding strategy and ii) an infection load driven leaf shedding strategy. The model predicts that ESS leaf shedding rates increase with nutrient availability. No effect of plant density on the ESS leaf shedding rate is found even though disease severity increases with plant density. When auto-infection, that is increased infection due to spores produced on the plant itself, plays a key role in further disease increase on the plant, shedding leaves removes disease that would otherwise contribute to disease increase on the plant itself. Consequently leaf shedding responses to infections may evolve. When external infection, that is infection due to immigrant spores, is the key determinant, shedding a leaf does not reduce the force of infection on the leaf shedding plant. In this case leaf shedding will not evolve. Under a low external disease pressure adopting an infection driven leaf shedding strategy is more efficient than adopting a constant leaf shedding strategy, since a plant adopting an infection driven leaf shedding strategy does not shed any leaves in the absence of infection, even when leaf shedding rates are high. A plant adopting a constant leaf shedding rate sheds the same amount of leaves regardless of the presence of infection. Based on the results we develop two hypotheses that can be tested if the appropriate plant material is available.

The utility of leaf flavonoids as taxonomic markers for some Malaysian species of the tribe Shoreae (Dipterocarpaceae)

A flavonoid survey was carried out on 45 taxa from the genera Shorea, Hopea, Parashorea, Neobalanocarpus, and Dryobalanops of the tribe Shoreae in the Dipterocarpaceae. The study showed significant chemotaxonomic differences in leaf flavonoid aglycone patterns and the presence of tannins in these taxa. The flavonoid patterns are useful in the delimitation of some taxa. For example, the genus Parashorea is distinguished by the universal presence of kaempferol 3-methyl ether, and the monotypic genus Neobalanocarpus is unique in not producing ellagic and gallo tannins. The presence of chalcones and flavone C-glycosides supports the separation of the genus Hopea into two sections, section Dryobalanoides and section Hopea in Ashton's classification, which is based on the type of venation. The flavonoid distributions in this study show that they can be very useful for differentiating between the Balau group in the genus Shorea, and some scaly barked Hopea species, particularly H. helferi (lintah bukit), H. nutans (giam), and H. ferrea (malut). (C) 2008 The Linnean Society of London.

Changes in the flavonoid and phenolic acid contents and antioxidant activity of red leaf lettuce (Lollo Rosso) due to cultivation under plastic films varying in ultraviolet transparency

Red leaf lettuce (Lollo Rosso) was grown under three types of plastic films that varied in transparency to UV radiation (designated as UV block, UV low, and UV window). Flavonoid composition was determined by high-performance liquid chromatography (HPLC), total phenolics by the Folin-Ciocalteu assay, and antioxiclant capacity by the oxygen radical absorbance capacity (ORAC) assay. Exposure to increased levels of UV radiation during cultivation caused the leaves to redden and increased concentrations of total phenols and the main flavonoids, quercetin and cyanidin glycosides, as well as luteolin conjugates and phenolic acids. The total phenol content increased from 1.6 mg of gallic acid equivalents (GAE)/g of fresh weight (FW) for lettuce grown under UV block film to 2.9 and 3.5 mg of GAE/g of FW for lettuce grown under the UV low and UV window films. The antioxiclant activity was also higher in lettuce exposed to higher levels of UV radiation with ORAC values of 25.4 and 55.1 mu mol of Trolox equivalents/g of FW for lettuce grown under the UV block and UV window films, respectively. The content of phenolic acids, quantified as caffeic acid, was also different, ranging from 6.2 to 11.1 mu mol/g of FW for lettuce cultivated under the lowest and highest UV exposure plastic films, respectively. Higher concentrations of the flavonoid glycosides were observed with increased exposure to UV radiation, as demonstrated by the concentrations of aglycones after hydrolysis, which were cyanidin (ranging from 165 to 793 mu g/g), quercetin (ranging from 196 to 880,mu g/g), and luteolin (ranging from 19 to 152 mu g/g). The results demonstrate the potential of the use of UV-transparent plastic as a means of increasing beneficial flavonoid content of red leaf lettuce when the crop is grown in polytunnels.

Changes in the flavonoid and phenolic acid contents and antioxidant activity of red leaf lettuce (Lollo Rosso) due to cultivation under plastic films varying in ultraviolet transparency

Red leaf lettuce (Lollo Rosso) was grown under three types of plastic films that varied in transparency to UV radiation (designated as UV block, UV low, and UV window). Flavonoid composition was determined by high-performance liquid chromatography (HPLC), total phenolics by the Folin-Ciocalteu assay, and antioxiclant capacity by the oxygen radical absorbance capacity (ORAC) assay. Exposure to increased levels of UV radiation during cultivation caused the leaves to redden and increased concentrations of total phenols and the main flavonoids, quercetin and cyanidin glycosides, as well as luteolin conjugates and phenolic acids. The total phenol content increased from 1.6 mg of gallic acid equivalents (GAE)/g of fresh weight (FW) for lettuce grown under UV block film to 2.9 and 3.5 mg of GAE/g of FW for lettuce grown under the UV low and UV window films. The antioxiclant activity was also higher in lettuce exposed to higher levels of UV radiation with ORAC values of 25.4 and 55.1 mu mol of Trolox equivalents/g of FW for lettuce grown under the UV block and UV window films, respectively. The content of phenolic acids, quantified as caffeic acid, was also different, ranging from 6.2 to 11.1 mu mol/g of FW for lettuce cultivated under the lowest and highest UV exposure plastic films, respectively. Higher concentrations of the flavonoid glycosides were observed with increased exposure to UV radiation, as demonstrated by the concentrations of aglycones after hydrolysis, which were cyanidin (ranging from 165 to 793 mu g/g), quercetin (ranging from 196 to 880,mu g/g), and luteolin (ranging from 19 to 152 mu g/g). The results demonstrate the potential of the use of UV-transparent plastic as a means of increasing beneficial flavonoid content of red leaf lettuce when the crop is grown in polytunnels.

A model for the evolution of pathogen-induced leaf shedding

A size-structured plant population model is developed to study the evolution of pathogen-induced leaf shedding under various environmental conditions. The evolutionary stable strategy (ESS) of the leaf shedding rate is determined for two scenarios: i) a constant leaf shedding strategy and ii) an infection load driven leaf shedding strategy. The model predicts that ESS leaf shedding rates increase with nutrient availability. No effect of plant density on the ESS leaf shedding rate is found even though disease severity increases with plant density. When auto-infection, that is increased infection due to spores produced on the plant itself, plays a key role in further disease increase on the plant, shedding leaves removes disease that would otherwise contribute to disease increase on the plant itself. Consequently leaf shedding responses to infections may evolve. When external infection, that is infection due to immigrant spores, is the key determinant, shedding a leaf does not reduce the force of infection on the leaf shedding plant. In this case leaf shedding will not evolve. Under a low external disease pressure adopting an infection driven leaf shedding strategy is more efficient than adopting a constant leaf shedding strategy, since a plant adopting an infection driven leaf shedding strategy does not shed any leaves in the absence of infection, even when leaf shedding rates are high. A plant adopting a constant leaf shedding rate sheds the same amount of leaves regardless of the presence of infection. Based on the results we develop two hypotheses that can be tested if the appropriate plant material is available.

Evolution of the eye-end design of a composite leaf spring for heavy axle loads

This paper presents the design evolution process of a composite leaf spring for freight rail applications. Three designs of eye-end attachment for composite leaf springs are described. The material used is glass fibre reinforced polyester. Static testing and finite element analysis have been carried out to obtain the characteristics of the spring. Load-deflection curves and strain measurement as a function of load for the three designs tested have been plotted for comparison with FEA predicted values. The main concern associated with the first design is the delamination failure at the interface of the fibres that have passed around the eye and the spring body, even though the design can withstand 150 kN static proof load and one million cycles fatigue load. FEA results confirmed that there is a high interlaminar shear stress concentration in that region. The second design feature is an additional transverse bandage around the region prone to delamination. Delamination was contained but not completely prevented. The third design overcomes the problem by ending the fibres at the end of the eye section.

The utility of leaf flavonoids as taxonomic markers for some Malaysian species of the tribe Shoreae (Dipterocarpaceae)

A flavonoid survey was carried out on 45 taxa from the genera Shorea, Hopea, Parashorea, Neobalanocarpus, and Dryobalanops of the tribe Shoreae in the Dipterocarpaceae. The study showed significant chemotaxonomic differences in leaf flavonoid aglycone patterns and the presence of tannins in these taxa. The flavonoid patterns are useful in the delimitation of some taxa. For example, the genus Parashorea is distinguished by the universal presence of kaempferol 3-methyl ether, and the monotypic genus Neobalanocarpus is unique in not producing ellagic and gallo tannins. The presence of chalcones and flavone C-glycosides supports the separation of the genus Hopea into two sections, section Dryobalanoides and section Hopea in Ashton's classification, which is based on the type of venation. The flavonoid distributions in this study show that they can be very useful for differentiating between the Balau group in the genus Shorea, and some scaly barked Hopea species, particularly H. helferi (lintah bukit), H. nutans (giam), and H. ferrea (malut). (C) 2008 The Linnean Society of London.

An assessment of the MODIS collection 5 leaf area index product for a region of mixed coniferous forest

Canopy leaf area index (LAI), defined as the single-sided leaf area per unit ground area, is a quantitative measure of canopy foliar area. LAI is a controlling biophysical property of vegetation function, and quantifying LAI is thus vital for understanding energy, carbon and water fluxes between the land surface and the atmosphere. LAI is routinely available from Earth Observation (EO) instruments such as MODIS. However EO-derived estimates of LAI require validation before they are utilised by the ecosystem modelling community. Previous validation work on the MODIS collection 4 (c4) product suggested considerable error especially in forested biomes, and as a result significant modification of the MODIS LAI algorithm has been made for the most recent collection 5 (c5). As a result of these changes the current MODIS LAI product has not been widely validated. We present a validation of the MODIS c5 LAI product over a 121 km2 area of mixed coniferous forest in Oregon, USA, based on detailed ground measurements which we have upscaled using high resolution EO data. Our analysis suggests that c5 shows a much more realistic temporal LAI dynamic over c4 values for the site we examined. We find improved spatial consistency between the MODIS c5 LAI product and upscaled in situ measurements. However results also suggest that the c5 LAI product underestimates the upper range of upscaled in situ LAI measurements.

The influence of powdery mildew infection on photosynthesis, chlorophyll fluorescence, leaf chlorophyll and carotenoid content of three woody plant species

The effect of powdery mildew development on photosynthesis, chlorophyll fluorescence, leaf chlorophyll and carotenoid concentrations on three woody plants frequently planted in urban environments was studied. Rates of photosynthetic CO2 fixation were rapidly reduced in two of the three genotypes tested prior to visible signs of infection. Effects on chlorophyll fluorescence (Fo, Fv/Fo, Fv/Fm), leaf chlorophyll and carotenoid content were not manifest until >25 per cent of the leaf area was observed to be covered by mycelial growth indicating reduced photo-synthetic rates during the early stages of infection were not due to degradation of the leaf chloroplast structure. Observation of the fluorescence transient (OJIP curves) showed powdery mildew infection impairs photosynthetic electron transport system by reducing the size but not heterogeneity of the plastoquninone pool, effecting both the acceptor and donor side of photosystem II. Impairment of the photosynthetic electron transport system was reflected by reduced values of a performance index used in this investigation as a measure of photochemical events within photosystem II electron transport. In addition interpretation of the fluorescence data indicated powdery mildew infection may impair the photo-protective process that facilitates the dissipation of excess energy within leaf tissue.

Dose response relationship of droplet applications for the leaf-specific weed control in vegetable crops

As a prelude to leaf-specific weed control using droplets targeted by a robotic weeder, amounts of herbicide required to control individual weed seedlings were estimated. Roundup Biactive was applied at doses equivalent to 1/128th to four times the recommended rate in addition to undiluted Roundup and water controls. Based on the mean ground cover of the seedlings, the recommended dose (1.5 l ha 1) was estimated and droplets were applied to individual plants by micropipette. All treatments contained 1% AS 500 SL, Agromix (adjuvant). Three weeks after application dry weights (DW) of each seedling was recorded. DW reductions of 50% were achieved in the five species tested at less than the recommended rate whereas only in one species was a 90% reduction obtained at that rate. In Galium aparine for example, 19.3 μg of glyphosate reduced DW per plant by 90% compared to the recommended dose of 8.4 μg.

Proteomic analysis of the medicinal plant Artemisia annua: data from leaf and trichome extracts

This article contains raw and processed data related to research published by Bryant et al. [1]. Data was obtained by MS-based proteomics, analysing trichome-enriched, trichome-depleted and whole leaf samples taken from the medicinal plant Artemisia annua and searching the acquired MS/MS data against a recently published contig database [2] and other genomic and proteomic sequence databases for comparison. The processed data shows that an order-of-magnitude more proteins have been identified from trichome-enriched Artemisia annua samples in comparison to previously published data. Proteins known to have a role in the biosynthesis of artemisinin and other highly abundant proteins were found which imply additional enzymatically driven processes occurring within the trichomes that are significant for the biosynthesis of artemisinin.

Global transcript analysis of rice leaf and seed using SAGE technology.

We have compiled two comprehensive gene expression profiles from mature leaf and immature seed tissue of rice (Oryza sativa ssp. japonica cultivar Nipponbare) using Serial Analysis of Gene Expression (SAGE) technology. Analysis revealed a total of 50 519 SAGE tags, corresponding to 15 131 unique transcripts. Of these, the large majority (approximately 70%) occur only once in both libraries. Unexpectedly, the most abundant transcript (approximately 3% of the total) in the leaf library was derived from a type 3 metallothionein gene. The overall frequency profiles of the abundant tag species from both tissues differ greatly and reveal seed tissue as exhibiting a non-typical pattern of gene expression characterized by an over abundance of a small number of transcripts coding for storage proteins. A high proportion ( approximately 80%) of the abundant tags (> or = 9) matched entries in our reference rice EST database, with many fewer matches for low abundant tags. Singleton transcripts that are common to both tissues were collated to generate a summary of low abundant transcripts that are expressed constitutively in rice tissues. Finally and most surprisingly, a significant number of tags were found to code for antisense transcripts, a finding that suggests a novel mechanism of gene regulation, and may have implications for the use of antisense constructs in transgenic technology.

Effects of host plant drought stress on the performance of the bird cherry-oat aphid, Rhopalosiphum padi (L.): a mechanistic analysis

1. The growth (increase in height and leaf number) of four grass species was reduced by a -0.5 MPa drought stress, but the performance of an associated herbivore, Rhopalosiphum padi (L.), was not affected consistently. The intrinsic rate of increase of R. padi was reduced by drought stress on three grass species, including Dactylis glomerata (L.), but was unaffected on Arrhenatherum elatius (L.). Therefore, there is no general relationship in the effect of plant drought on an insect herbivore, even among closely related host plant species. 2. Drought stress increased the quality of plant phloem sap, as indicated by increased sieve element osmotic pressure and essential amino acid concentrations. Thus, diet quality could not account for the reduced performance of R. padi under drought stress. The concentration of essential amino acids in the phloem of well-watered A. elatius was, however, lower than that of well-watered D. glomerata, correlating with the decreased performance of aphids on well-watered A. elatius. 3. There were no differences in aphid feeding duration between watering treatments or plant species but sap ingestion rates were reduced significantly under drought stress. 4. Using the measure of dietary amino acid concentrations and the estimate of sap ingestion, the essential amino acid flux through aphids was calculated. Compared with the flux through aphids feeding on well-watered D. glomerata, there was a reduction in aphids feeding on drought-stressed D. glomerata and drought-stressed A. elatius due to lower sap ingestion rates. The flux through aphids on well-watered A. elatius was also reduced due to low phloem essential amino acid concentrations. Thus, the performance of an aphid is correlated with the availability and accessibility of essential amino acids.