Search results for " Leaves"
showing 10 items of 251 documents
A β-1,3 Glucan Sulfate Induces Resistance in Grapevine against Plasmopara viticola Through Priming of Defense Responses, Including HR-like Cell Death
2008
Sulfated laminarin (PS3) has been shown previously to be an elicitor of plant defense reactions in tobacco and Arabidopsis and to induce protection against tobacco mosaic virus. Here, we have demonstrated the efficiency of PS3 in protecting a susceptible grapevine cultivar (Vitis vinifera cv. Marselan) against downy mildew (Plasmopara viticola) under glasshouse conditions. This induced resistance was associated with potentiated H2O2 production at the infection sites, upregulation of defense-related genes, callose and phenol depositions, and hypersensitive response-like cell death. Interestingly, similar responses were observed following P. viticola inoculation in a tolerant grapevine hybri…
Long-term ozone exposure of potato: Free radical content and leaf injury analysed by Q-band ESR spectroscopy and image analysis
2008
This paper presents Q-band electron spin resonance (ESR) studies on free radicals (FR) generated in potato leaves exposed to different O(3) levels in open-top chambers (OTC), together with a quantitative study of the relationship between FR signal intensity and area of potato leaf damage. The advantages of Q-band when compared to X-band ESR spectroscopy are analysed, the main advantage being an absence of overlapping between Mn(II) and FR signals, allowing a quantitative study of FR signal intensity. This study also reports on a graphical method developed to quantitatively measure the damaged area on leaves caused by ozone exposure. Results indicate a direct relationship between FR signal i…
The use of leaves of Rosmarinus officinalis L. as samplers for polycyclic aromatic hydrocarbons. Assessment of air quality in the area of Palermo
2002
The quantitative analysis of polycyclic aromatic hydrocarbons (PAHs) in vegetables and animals allows us to evaluate the quality of air, in a determined geographic area, without the need of making long samplers with complicate instrumentation. In this work, Rosmarinus officinalis leaves have been used as passive samplers. In particular, this plant was chosen because it is widespread in the Mediterranean area and it is commonly found both in the metropolitan and in the peripheral areas of the city of Palermo. Results for the concentration of total polycyclic aromatic hydrocarbons (the sum of the 22 compounds) and the PAHs distribution in leaves from Rosmarinus officinalis are presented. Puri…
Pharmacological properties of the methanol extract from Mentha suaveolens Ehrh.
2002
The present study analyses the pharmacological activity in in vivo and in vitro models of the methanol extract obtained from the leaves and steams of Menta suaveolens Ehrh. This extract lacked toxicity, but exhibited a central nervous system depressant action; an analgesic effect in models of chemical and mechanical stimulation suggesting the induction of a peripheral analgesic response. The extract also exhibited an antiinflammatory action inhibiting the rat paw oedema induced by carrageenin. Moreover, the in vitro studies showed a significant diminution in the contractile effects induced by histamine, serotonin and acetylcholine.
Metabolites from Combretum dolichopetalum and its associated endophytic fungus Nigrospora oryzae--Evidence for a metabolic partnership.
2015
Abstract A new altersolanol derivative, 4-dehydroxyaltersolanol A ( 9 ), along with two known sesquiterpenoids, ( S )-7′-hydroxyabscisic acid ( 7 ) and ( S )-abscisic acid ( 8 ) were obtained from the endophytic fungus, Nigrospora oryzae , isolated from leaves of Combretum dolichopetalum . The host plant yielded six known compounds including ellagic acid ( 1 ), 3, 3′, 4-tri-O-methylellagic acid ( 2 ), arjunolic acid ( 3 ), 4′-dihydrophaseic acid ( 4 ), echinulin ( 5 ) and arestrictin B ( 6 ). Close structural similarities with regard to compounds 4 , 7 and 8 were observed between the metabolites from the host plant and those of the endophytic fungus. Furthermore compounds 5 and 6 are relate…
Arabidopsis copper transport protein COPT2 participates in the crosstalk between iron deficiency responses and low phosphate signaling
2013
[EN] Copper and iron are essential micronutrients for most living organisms because they participate as cofactors in biological processes, including respiration, photosynthesis, and oxidative stress protection. In many eukaryotic organisms, including yeast (Saccharomyces cerevisiae) and mammals, copper and iron homeostases are highly interconnected; yet, such interdependence is not well established in higher plants. Here, we propose that COPT2, a high-affinity copper transport protein, functions under copper and iron deficiencies in Arabidopsis (Arabidopsis thaliana). COPT2 is a plasma membrane protein that functions in copper acquisition and distribution. Characterization of the COPT2 expr…
Transgenerational effects of plant sex and arbuscular mycorrhizal symbiosis
2013
In gynodioecious plants, females are predicted to produce more and/or better offspring than hermaphrodites in order to be maintained in the same population. In the field, the roots of both sexes are usually colonized by arbuscular mycorrhizal (AM) fungi. Transgenerational effects of mycorrhizal symbiosis are largely unknown, although theoretically expected. We examined the maternal and paternal effects of AM fungal symbiosis and host sex on seed production and posterior seedling performance in Geranium sylvaticum, a gynodioe- cious plant. We hand-pollinated cloned females and hermaphrodites in symbiosis with AM fungi or in nonmycorrhizal conditions and measured seed number and mass, and see…
The Arabidopsis COPT6 Transport Protein Functions in Copper Distribution Under Copper-Deficient Conditions
2013
Copper (Cu), an essential redox active cofactor, participates in fundamental biological processes, but it becomes highly cytotoxic when present in excess. Therefore, living organisms have established suitable mechanisms to balance cellular and systemic Cu levels. An important strategy to maintain Cu homeostasis consists of regulating uptake and mobilization via the conserved family of CTR/COPT Cu transport proteins. In the model plant Arabidopsis thaliana, COPT1 protein mediates root Cu acquisition, whereas COPT5 protein functions in Cu mobilization from intracellular storage organelles. The function of these transporters becomes critical when environmental Cu bioavailability diminishes. Ho…
Toward the definition of a carbon budget model: seasonal variation and temperature effect on respiration rate of vegetative and reproductive organs o…
2009
Summary This study, as a preliminary step toward the definition of a carbon budget model for pistachio trees (Pistacia vera L.), aimed at estimating and evaluating the dynamics of respiration of vegetative and reproductive organs of pistachio tree. Trials were performed in 2005 in a commercial orchard located in Sicily (370 m a.s.l.) on five bearing 20-year-old pistachio trees of cv. Bianca grafted onto Pistachio terebinthus L. Growth analyses and respiration measurements were done on vegetative (leaf) and reproductive (infructescence) organs during the entire growing season (April–September) at biweekly intervals. Results suggested that the respiration rates of pistachio reproductive and v…
Radio-metabolite analysis of carbon-11 biochemical partitioning to non-structural carbohydrates for integrated metabolism and transport studies.
2013
Metabolism and phloem transport of carbohydrates are interactive processes, yet each is often studied in isolation from the other. Carbon-11 ((11)C) has been successfully used to study transport and allocation processes dynamically over time. There is a need for techniques to determine metabolic partitioning of newly fixed carbon that are compatible with existing non-invasive (11)C-based methodologies for the study of phloem transport. In this report, we present methods using (11)C-labeled CO2 to trace carbon partitioning to the major non-structural carbohydrates in leaves-sucrose, glucose, fructose and starch. High-performance thin-layer chromatography (HPTLC) was adapted to provide multis…