Regulating Internet Trade in CITES Species

International trade in species that are or may be endangered by collection from the wild is regulated under the Convention on International Trade in Endangered Species of wild fauna and flora (CITES) for 176 member States (Parties). Internet commerce is a relatively new route for such trade. In 2007, the CITES Secretariat asked Parties to collect information on internet wildlife trade and report problems and implemented regulations. The reports indicated it was difficult to even approximate the influence of e-commerce on CITES-listed species (CITES Secretariat 2009). We report a case study in which we quantified international transactions over an internet auction site of CITES-listed cacti …

Effects of foliar application of glycine betaine and chitosan on Puccinellia distans (Jacq.) Pari, subjected to salt stress.

Introduction:Using brackish water for irrigation may expose turfgrasses to salinity stress.Employing the best treatments to maintain high-quality turfs under saline conditions is animportant requirement for turfgrass management.Methods:We tested the response of ahalophyte grass,Puccinellia distans, to irrigation with saline solutions and to foliarapplication of two osmoprotectants, such as glycine betaine (GB) or chitosan (CH). Plantswere grown in pots under controlled conditions and irrigated with 200 mM or 600 mM ofNaCl solutions. The response to salinity treatments and osmoprotectant application wasevaluated after 90 days by measuring leaffiring, leaf density, shoot length and biomass, r…

Nuove frontiere della fotosintesi clorofilliana: la foglia artificiale

Per molti anni la scienza ha tentato di riprodurre il processo fotosintetico delle piante, che permette di utilizzare la luce del sole e l'anidride carbonica dell'atmosfera per produrre gli zuccheri necessari al loro metabolismo. Nella primavera del 2010 sui quotidiani compare la notizia rivoluzionaria della creazione di una foglia artificiale, capace di trasformare la luce in una fonte di energia utilizzabile dall'uomo. Su quali principi si basa questa scoperta? Quanto ha di analogo con i processi che avvengono nelle foglie? E quanto siamo vicini all'applicazione su vasta scala di questa innovazione tecnologica?

Interspecific variation in total phenolic content in temperate brown algae

Marine algae synthesize secondary metabolites such as polyphenols that function as defense and protection mechanisms. Among brown algae, Fucales and Dictyotales (Phaeophyceae) contain the highest levels of phenolic compounds, mainly phlorotannins, that play multiple roles. Four temperate brown algae (Cystoseira amentacea, Cystoseira compressa, Dictyopteris polypodioides and Padina pavonica) were studied for total phenolic contents. Total phenolic content was determined colorimetrically with the Folin-Ciocalteu reagent. Significant differences in total phenolic content were observed between leathery and sheetlike algae and also within each morphological group. Among the four species, the she…

Effects of water deficit on the leaf water relations of pot-grown olive cultivars

An experiment was conducted to investigate the water relations of potted young olive trees (Olea europaea L.) cultivar ‘Biancolilla’, ‘Giarraffa’ and ‘Nocellara del Belice’ during water stress and after relief from stress. The aim was to highlight the different responses of the three cultivars and obtain a decision-making aid for planning an efficient watering schedule for potted plants grown in nurseries. Leaf water potential (Ψ), relative water content (RWC) and conductance to water vapour (gL) were measured in three-year-old plants. All three olive cultivars were able to survive the severe stress imposed by withholding water for three weeks, but gas exchange was strongly impaired and rec…

Water relations in young manna ash trees grown under drought conditions

Monitoring of alien aquatic plants in the inland waters of Sicily (Italy)

Updated and reliable data on the presence and distribution of alien aquatic plant species in Sicily are lacking, and there is a need to fill this gap for a proper and efficient management of freshwater ecosystems and biodiversity. This paper reviews the available knowledge about alien aquatic vascular plants in the inland waters of Sicily (Italy). The aim is to provide an updated checklist, as a first step in the study of the impact of those plants on the native species and ecosystems of this Mediterranean island. The paper focuses on the strictly aquatic species (hydrophytes), excluding emergent macrophytes. Four species were listed, all of them free-floating and with American origin. Most…

VARIAZIONI DI ALCUNI PARAMETRI FISIOLOGICI IN OLEA EUROPAEA ‘BIANCOLILLA’ COLTIVATA IN DIFFERENTI REGIMI IRRIGUI

ECOFISIOLOGIA DELLE OLEACEAE: EFFETTI DELLO STRESS IDRICO SULLE PRINCIPALI CULTIVAR DI OLIVO DEL PANORAMA AGRICOLO SICILIANO

Le specie e le cultivar che crescono in ambiente mediterraneo rispondono in maniera diversa alle condizioni di aridita', con differenti adattamenti ecofisiologici. Sono state misurate le variazioni in alcuni parametri quali potenziale idrico fogliare, conduttanza stomatica, attività di superossido dismutasi e perossidasi, contenuto di mannitolo in differenti specie di frassino da manna e cultivar di olivo cresciute in regimi irrigui differenti.

La fitodepurazione: esperienze di laboratorio e avviamento di un impianto pilota.

La fitodepurazione è una tecnologia sempre più utilizzata ai fini del risanamento ambientale. Sono stati misurati in laboratorio alcuni parametri fisiologici (accrescimento delle radici, contenuto di pigmenti fotosintetici, attività fotosintetica, enzimi antiossidanti, contenuto di metalli pesanti) di piante di papiro allevate in soluzioni contenenti metalli pesanti a diverse concentrazioni. Contemporaneamente è stato avviato un impianto pilota di fitodepurazione con vasche contenenti esemplari di Typha latifolia e Cyperus alternifolius.

Antibacterial activity and HPLC analysis of extracts from Mediterranean brown algae

The antibacterial activity of methanolic extracts of eight Mediterranean brown algae belonging to the genera Cystoseira sensu lato, Dictyopteris and Padina was investigated. Extracts from Sargassaceae showed antibacterial activity. Specifically, Carpodesmia crinita and Carpodesmia brachycarpa extracts inhibited the growth of the Gram-positive strain Kocuria rhizophila whereas Cystoseira compressa and Carpodesmia amentacea extracts showed antibacterial activity against the Gram-positive strains, Kocuria rhizophila and Staphylococcus aureus. None of them inhibited the growth of the Gram-negative bacterium Escherichia coli. The extracts of Cystoseira sp. pl. and Treptacantha ballesterosii did …

INTERSPECIFIC VARIATION IN TOTAL PHENOLIC CONTENT IN TEMPERATE BROWN ALGAE

The aim of this study was to focus on interspecific variation of total phenolic contents (TPC) in temperate brown algae also considering their relationship with environmental conditions. In particular, we compared the TPC of four species characterized by different thallus morphology, growth cycle and bathymetric level: Cystoseira amentacea (C. Agardh) Bory, Cystoseira compressa (Esper) Gerloff & Nizamuddin, Dictyopteris polypodioides (A.P. De Candolle) J.V. Lamouroux and Padina pavonica (Linnaeus) Thivy, collected in summer 2011 from the north-western coast of Sicily.

Effetti dell’applicazione fogliare di glicinbetaina e chitosano su Puccinellia distans (Jacq.) Parl. Sottoposta s stress salino

Recovery from water stress in laurel plants: influence of short term potassium fertilization

Plant xylem hydraulic conductance varies with changes in sap solute concentrations, particularly potassium, a phenomenon known as 'ionic effect'. In well-watered Laurus nobilis plants, short term potassium fertilization increased xylem sap potassium concentration, resulting in an increase in plant hydraulic conductance (Kplant), leaf-specific conductivity of the shoot (kshoot) and transpiration rate (Eplant). The ionic effect is enhanced in embolized stems, where it can compensate the cavitation-induced loss of hydraulic conductance. The aim of this work was to test if water-stressed potassium-starved laurel plants could recover earlier from stress when irrigated with a potassium solution i…

Investigating the ecology of Chara cf. baltica (Characeae) in the Lago Preola ecosystem (Sicily, Italy)

Lago Preola is a small lake, located in SW Sicily, in a karstic depression within the Nature Reserve “Lago Preola e Gorghi Tondi”. With about 33 ha (maximum depth: 2 m), it is the widest of the 5 natural lakes occurring in the Reserve. The presence of species of conservation concern (e.g., Emys trinacris, the Sicilian Pond Turtle, and several migratory birds), but also of invasive alien species (e.g., Procambarus clarckii, the Red Swamp Crayfish), has been reported for the area. The flora of terrestrial habitats surrounding the basins has been studied extensively, while the aquatic flora and vegetation have not been studied in detail. The coastal aquifer supplying groundwater to the study a…

Water recycling in leaves of Lithops (Aizoaceae)

Lithops plants consist of a pair of succulent leaves inserted on a short stem; each growing season young leaves develop in a cavity formed between the older pair. Young leaves can take up water from the older pair allowing the plant to maintain growth and leaf expansion even without external supply of water. Recycling water between vegetative organs is one of the possible adaptation strategies of plants under drought stress, but it had never been demonstrated experimentally in Lithops. The methodology used to verify the existence of water redistribution from old leaves to young leaves was fluorescence microscopy, using two dyes to follow the water pathway inside the plant: Sulforhodamine G …

Total phenolic content in brown algae from the Sicilian coast

Phlorotannins are polyphenolic secondary metabolites found in almost all brown algae that function as defense against grazers, pathogens and epiphytes but are also involved in photoprotection mechanisms. These com- pounds, produced in the Golgi apparatus, are accumulated in cytoplasm, within vesicules called physodes, or bound to the cell wall. The concentration of phlorotannins differs within and between species, shows geograph- ical variations but may be also affected by abiotic or biotic factors. We present here an overview of the studies carried out on total phenolic content in brown algae collected along the north-western coast of Sicily. The aims of these studies were in particular a)…

Leaf water relation traits in typical Sicilian varieties of Vitis vinifera L.

In Italy, grapevines are extensively cultivated, with Sicily representing one of the most significant wine regions. The high number of autochthonous grapevine varieties represents an important source of genetic diversity, and the many Sicilian varieties have anatomical and physiological traits that allow them to resist to different levels of drought stress. We investigated the water relation parameters of four cultivars of Vitis vinifera L. (Catarratto, Corinto, Nero d'Avola and Zibibbo) and characterized their leaf hydraulics. Measurements were conducted during summer on plants growing in the experimental field of the IBBR-CNR near Palermo. Daily patterns of leaf water potential (Yleaf) an…

Is in vitro micrografting a possible valid alternative to traditional micropropagation in Cactaceae? Pelecyphora aselliformis as a case study

Several taxa of Cactaceae are endangered by overcollection for commercial purposes, and most of the family is included in the Convention on International Trade in Endangered Species of Fauna and Flora (CITES). Micropropagation may play a key role to keep the pressure off wild populations and contribute to ex situ conservation of endangered taxa. One of the limits of micropropagation is the species-specific requirement of plant regulators for each taxon and sometimes even for different genotypes. With the micrografting technique the rootstock directly provides the scion with the necessary hormonal requirements. In this paper we present data on in vitro grafting of Pelecyphora aselliformis Eh…

Effetti dell'applicazione fogliare di glicinbetaina su Festuca arundinacea (Schreb) sottoposta a stress salino

CHARACTERIZATION OF WATER RELATION TRAITS IN WILD SICILIAN POPULATIONS OF BRASSICA

The aims of this work are to Investigate the variability in water relation traits among wild Brassica relatives adapted to arid and saline environments and to Identify specific differences in physiological traits that may be used to improve cultivated relatives widely used in our diet, such as broccoli, cabbage and kale.

Does short-term potassium fertilization improve recovery from drought stress in laurel?

Xylem hydraulic conductance varies in response to changes in sap solute content, and in particular of potassium (K(+)) ion concentration. This phenomenon, known as the 'ionic effect', is enhanced in embolized stems, where it can compensate for cavitation-induced loss of hydraulic conductance. Previous studies have shown that in well-watered laurel plants (Laurus nobilis L.), potassium concentration of the xylem sap and plant hydraulic conductance increased 24 h after fertilization with KCl. The aim of this work was to test whether water-stressed laurel plants, grown under low potassium availability, could recover earlier from stress when irrigated with a KCl solution instead of potassium-fr…

Short-term effects of potassium fertilization on the hydraulic conductance of Laurus nobilis L.

This study reports experimental evidence on the effect of short term potassium fertilization on potassium uptake, tissue concentration and hydraulic conductance of pot-grown laurel plants. Potassium uptake and loading into the xylem of laurel seedlings increased within 24 h from fertilization. Potassium was not accumulated in roots and leaves, but the [K+] of xylem sap was 80% higher in fertilized plants (+K) than in potassium starved plants (-K), likely as a result of recirculation between xylem and phloem. This increase in xylem sap [K+] resulted in a 45% increase in transpiration rate, a 30% increase in plant hydraulic conductance (Kplant) and a 120% increase in leaf specific conductivit…

Valutazione della resistenza allo stress salino di Puccinellia distans (Jacq.) Parl. trattata con applicazioni fogliari dell'osmoregolatore glicinbetaina

Relazioni idriche di differenti cultivar di olivo coltivate in ambiente mediterraneo

Physio-morphological traits and drought stress responses in three wild Mediterranean taxa of Brassicaceae

Crop wild relatives (CWRs) have extremely relevant roles in biodiversity conservation, in investigating phylogeny and improving abiotic stress tolerance of crop plants. We screened the variability in leaf functional traits of three CWRs of kale crops (Brassica oleracea) from Sicily, Italy, grown in pots under well-watered and drought conditions. Our aim was to highlight traits in the different genotypes of endemic Sicilian threatened taxa. We measured several structural/anatomical traits (stomatal size, density and stomatal pore index—SPI, leaf mass per area—LMA) and leaf functional traits (stomatal conductance—gs, leaf water potential—ΨL, leaf temperature (TL), leaf relative water content—…

An Investigation of the Seasonal Pattern of Mannitol Content in Deciduous and Evergreen Species of the Oleaceae Growing in Northern Sicily

In several species of the Oleaceae, mannitol, already present at considerable levels, accumulates in response to stress. This family comprises both deciduous and evergreen species, and we investigated the role of mannitol in deciduous malacophyll and evergreen sclerophyll species growing under the same conditions in the field. The relationship between mannitol content and changes in rainfall or temperature was also studied. The mannitol content of leaves of Fraxinus ornus L., F. angustifolia Vahl., Olea europaea L. and Phillyrea media L. was determined by gas chromatography. Leaf samples were collected once a month for 1 year. In the two ash species, the seasonal pattern of mannitol content…

Studi sulla resistenza alla salinità di Puccinellia distans in camera controllata

Water relations of two Sicilian grapevine cultivars in response to potassium availability and drought stress

Abstract We investigated the response of two Sicilian grapevine cultivars, Catarratto and Nero d'Avola, to potassium deficiency and drought stress. Two-year-old plants grafted on 1103 Paulsen were grown in agriperlite, with or without potassium in the fertigation solution for six weeks, and subjected to moderate drought stress by suspending irrigation for one week. Potassium content of leaves, roots and xylem sap were measured with an ion-selective electrode. Changes in stomatal conductance, stem and leaf water potential and hydraulic conductance were compared between genotypes and treatments. Potassium deficiency led to significant decreases in leaf potassium content in both cultivars and …

Effects of drought and re-watering on water transport in Sedum sediforme (Jacq.) Pau

Effect of potassium fertilization on the hydraulic conductance of laurel plants

The effect of potassium fertilization on hydraulic conductance was tested in 2-year-old potted laurel seedlings, grown in a greenhouse at the Botanical Garden of Palermo. Plants were divided into a control group (+K) and a potassium starved group (-K). A set of randomly chosen -K plants received irrigation with 25 mM KCl (KCl plants) 24 hours before measurements, to test the short term effect of potassium fertilization. Measurements were carried out in July and October 2008. Whole-plant hydraulic conductance was measured by the evaporative flux method; root and shoot hydraulic conductance were measured by the vacuum chamber. Potassium availability or season did not significantly affect leaf…

Effect of salinity on Puccinellia distans (L.) Parl. treated with NaCl and foliarly applied glycinebetaine

Turfgrasses general appearance is much affected by environmental stresses because the species used for this purpose are particularly exigent in terms of technical inputs and water need. In the Mediterranean area, sometimes irrigation is provided by using waste water which may contain high concentrations of dissolved salts which can cause salt stress injury and poor turf quality. Puccinellia distans (L.) Parl. is a halophyte cool season grass that seems to have a high salinity tolerance when cultivated in sodic soils or in NaCl-rich hydroponic cultures. We investigated the response of P. distans to salinity in a soil culture in a controlled growth environment. The effect of different concent…

Water relations in developing leaves of Lithops hookeri (Berg.) Schwant (Aizoaceae – Ruschioideae)

A comparison of growth, gas exchange and productivity in Olea europaea cultivars growing on Mediterranean hills.

This work concerns the ecophysiology of olive cultivars growing on Mediterranean hills. Our aim was to quantify the photosynthetic efficiency of the cultivars in cultivation. In two hill areas, we tested the phenological and ecophysio- logical variability of olive cultivars grown on non-irrigated land, with different pedo-climatic characteristics. Cultivation area 1 falls within a natural protected area, while area 2 is on farming land. The cultivars selected (‘Biancolilla’, ‘Nocellara del Belice’ and ‘Giarraffa’) belong to the local genetic pool and require different amounts of water. We followed the phe- nological phases of shoot growth and drupe production. We studied leaf anatomy and ch…

Carbon and nitrogen isotopic values in Lithops aucampiae during leaf development.

Abstract Lithops (Aizoaceae) are succulent plants consisting of a pair of opposite succulent leaves inserted on an extremely short stem. The apical meristem produces a new leaf pair that develops between the older pair, recycling water and metabolites. This peculiar anatomy and growth form make ecophysiological studies quite challenging. Lithops are considered to have CAM metabolism, though experimental evidence is scarce. We followed the changes in carbon and nitrogen isotopic values in mature leaves, young leaves and roots, with the aim of investigating how the use of resources is optimized to achieve survival in extremely arid environments. Two-year-old plants of Lithops aucampiae were g…

Seasonal variation in total phenolic content of Dictyopteris polypodioides (Dictyotaceae) and Cystoseira amentacea (Sargassaceae) from the Sicilian coast

This study focuses on the differences in total phenolic content and its seasonal variations in two temperate brown algae, Cystoseira amentacea (C. Agardh) Bory and Dictyopteris polypodioides (A.P. De Candolle) J.V. Lamouroux, inhabiting respectively the infralittoral fringe and the upper infralittoral zone. Phenolic compounds are secondary metabolites, found in almost all brown algal orders, that function as defense against grazers, epiphytes and UV radiation. Total phenolic content was determined colorimetrically with the Folin-Ciocalteu reagent. Results showed significant differences in total phenol content between D. polypodioides and C. amentacea with higher values observed in the first…

Effects of water stress on Sicilian olive cultivars.

An experiment was conducted to investigate the water relations of potted young olive trees (Olea europaea L.) cultivar ‘Biancolilla’, ‘Giarraffa’ and ‘Nocellara del Belice’ during water stress and after relief from stress. The aim was to highlight the different responses of the three cultivars and obtain a decision-making aid for planning an efficient watering schedule for potted plants grown in nurseries. Leaf water potential (Ψ), relative water content (RWC) and conductance to water vapour (gL) were measured in three-year-old plants. All three olive cultivars were able to survive the severe stress imposed by withholding water for three weeks, but gas exchange was strongly impaired and rec…

Effetti dell'applicazione fogliare di glicinbetaina e chitosano su Puccinellia distans (Jacq.) Parl. sottoposta a stress salino

The water shuttling hypothesis in Lithops

Project and start up of a pilot phytoremediation system.

Seasonal variation in total phenolic content of Dictyopteris polypodioides (Dictyotaceae) and Cystoseira amentacea (Sargassaceae) from the Sicilian coast

Phlorotannins are polyphenolic secondary metabolites found in almost all brown algae that function as defense against grazers, pathogens and epiphytes but are also involved in photoprotection mechanisms. These compounds, produced in the Golgi apparatus, are accumulated in cytoplasm, within vesicules called physodes, or bound to the cell wall. The concentration of phlorotannins dif-fers within and between species, shows geographical variations but may be also affected by abiotic or biotic factors. Aims of this study were to evaluate: (i) the temporal variation of total phenolic content in two brown algae, Dictyopteris polypodioides and Cystoseira amentacea, living respec-tively in the upper …

The impact of alien vascular plants in the aquatic habitats of a mediterranean island: preliminary data and observations in Sicily

As is well known, invasive alien species pose a major global threat to the conservation of biodiversity, causing the extinction of native species and modifying ecosystem functions: this is true also for aquatic habitats, particularly susceptible to invasion due to usually high disturbance regimes and easy dispersal of propagules. The island of Sicily is one of the main hotspots of plant biodiversity, in the center of the Mediterranean basin; it hosts different types of freshwater habitats, both lentic (coastal wetlands, saltworks, temporary ponds, lakes, reservoirs) and lotic (springs, streams, permanent and seasonal rivers). As a first step of our analysis of the effects of the alien vascu…

Seasonal pattern of mannitol and malate accumulation in leaves of two manna ash species (Fraxinus ornusL. andF. angustifoliaVahl) growing in Sicily

ABSTRACT The content of mannitol and malate was assayed enzimatically during spring, summer and autumn, in leaves of two species of ash, Fraxinus ornus L. and Fraxinus angustifolia Vahl, traditionally cultivated in Sicily for the extraction of manna. Both species contain high levels of mannitol and show, on a dry weight basis, a 65–80% increase in the summer content of this polyol. The malate content differs in the two species: in F. ornus it shows a summer increase, but it is relatively low (65–115 µmol g-1 DW), while in F. angustifolia it is higher (275–318 µmol g-1 DW), but remains more or less constant throughout the year. The results suggest that in these species, under the local field…

The ancient irrigation system of the Palermo Plain (Sicily, Italy) as a substitute ecosystem: preliminary investigations on its aquatic flora

Many cities around the world are expanding, including in their perimeters green and blues spaces that could be crucial for the maintaining of biodiversity. Urban waterbodies are generally created to provide other services, but correctly managed they can provide also relevant ecosystem services. The Palermo Plain was characterized, in the past centuries, by several wetlands that were progressively destroyed (or “reclaimed”). The ancient irrigation system, probably set during the Arab domination (IX-XI century A.D.), became a substitute ecosystem able to host a significant biodiversity. Our research focused on the remains of this system, scattered in the relictual green areas of the Plain, an…

Tamarix arborea var. arborea and Tamarix parviflora: Two species valued for their adaptability to stress conditions.

The choice of stress resistant and highly adaptable species is a fundamental step for landscaping and ornamental purposes in arid and coastal environments such as those in the Mediterranean basin. The genus Tamarix L. includes about 90 species with a high endurance of adversity. We investigated the water relations and photosynthetic response of Tamarix arborea (Sieb. ex Ehrenb.) Bge. var. arborea and T. parviflora DC. growing in an urban environment. Both species showed no evidence of drought or salt stress in summer, and appeared to follow two strategies with T. arborea var. arborea investing in high carbon gain at the beginning of the summer, and then reducing photosynthetic activity at t…

Le macchine molecolari deputate alla costruzione e modificazione delle pareti delle cellule vegetali

Le pareti sono uno degli elementi funzionali caratterizzanti delle cellule vegetali, dove biosintesi, assemblaggio e rimodellamento sono sotto stretto controllo genetico e ambientale. La principale macchina molecolare coinvolta è la cellulosa sintasi, la cui attività permette la polimerizzazione degli zuccheri in cellulosa e la cui interazione con il citoscheletro determina l'accrescimento e la forma definitiva delle cellule mature. Altri meccanismi enzimatici sono ad oggi sotto investigazione per comprendere meglio come avvengono la costruzione e le modificazioni di questa struttura cellulare, che garantisce alle piante il necessario sostegno meccanico e fornisce al contempo all'uomo mater…

Effectiveness of glycinebetaine foliar application in relieving salt stress symptoms in two turf-grasses

Salinity is one of the problems that has to be dealt with in turf-grass management, due both to restrictions in freshwater use for landscape irrigation and exposition to salt stress in coastal areas. This has led to the need to select salinity tolerant genotypes and test management practices, such as the application of osmoprotectants, in order to maintain turf quality at acceptable costs. We compared the effects of irrigation with 600 mM NaCl and glycinebetaine (GB) application for 8 weeks on pot-grown weeping alkaligrass (Puccinellia distans (L.) Parl.) and tall fescue (Festuca arundinacea Schreb.). We selected two easily assessable parameters, total clippings fresh weight and chlorophyll…

Oxidative stress in olive trees (Olea europaea L.) under drought stress

An integrated proteomic and metabolomic study to evaluate the effect of nucleus-cytoplasm interaction in a diploid citrus cybrid between sweet orange and lemon.

Key message: Our results provide a comprehensive overview how the alloplasmic condition might lead to a significant improvement in citrus plant breeding, developing varieties more adaptable to a wide range of conditions. Abstract: Citrus cybrids resulting from somatic hybridization hold great potential in plant improvement. They represent effective products resulting from the transfer of organelle-encoded traits into cultivated varieties. In these cases, the plant coordinated array of physiological, biochemical, and molecular functions remains the result of integration among different signals, which derive from the compartmentalized genomes of nucleus, plastids and mitochondria. To dissect …

Effects of temperature on total phenolic compounds in Cystoseira amentacea (C. Agardh) Bory (Fucales, Phaeophyceae) from southern Mediterranean Sea

The aim of this study was to test the effects of temperature on phenolic content of the brown seaweed Cystoseira amentacea. Phenolic compounds are secondary metabolites involved in different protection mechanisms as, for example, against grazers, epiphytes and UV radiation. Seasonal variations of phenolic content in C. amentacea were analysed and laboratory experiments, in which C. amentacea was exposed to an increase of temperature (25°C and 30°C), were performed. Total phenolic content (TPC) was determined colorimetrically with the Folin–Ciocalteu reagent. In C. amentacea, a seasonal pattern in TPC was observed, with a maximum value in winter-spring. C. amentacea responded significantly t…

Risposte agli stress ambientali in CYSTOSEIRA (C. AGARDH): effetti della temperatura sul contenuto dei composti fenolici

Phenolic compounds are secondary metabolites involved in different protection mechanisms as, for example, against grazers, epiphytes and UV radiation. Seasonal variations of phenolic content in C. amentacea were analysed and laboratory experiments, in which C. amentacea was exposed to an increase of temperature (258C and 308C), were performed. Total phenolic content (TPC) was determined colorimetrically with the Folin–Ciocalteu reagent. In C. amentacea, a seasonal pattern in TPC was observed, with a maximum value in winter-spring. C. amentacea responded significantly to the temperature treatments with a consistent decrease in TPC after 48 h.

Potassium deficiency and drought stress in grapevine cultivars

Potassium availability affects drought responses in plants through several metabolic roles, among which stomatal regulation, cell growth and xylem hydraulics. Vitis vinifera L. is a highly valuable crop and several genotypes have been selected during its millennial cultivation. Varieties show differences in their adaptability to stress conditions, making them more or less suitable to certain climatic and edaphic conditions. The varieties cultivated in Sicily are characterized by high variability. We investigated the response of two Sicilian cultivars (Nero d'Avola and Catarratto) to potassium deficiency and drought stress. Two-year-old grafted plants were grown in agriperlite, with or witho…

Usefulness of Cyperus alternifolius L. for water and soil reclamation: effect of copper, cadmium, and chromium on antioxidant systems

Water Potential Gradients between Old and Developing Leaves in Lithops (Aizoaceae).

Lithops plants consist of a pair of opposite succulent leaves inserted on a short stem. The apical meristem produces a new pair of leaves within the old one every growing season, recycling water from the old leaves. Since there are no data on water relations between the two pairs of leaves, we measured leaf water potential at different stages of development with a pressure chamber. Osmotic potential of cell sap was measured with a cryoscopic osmometer and turgor pressure was calculated indirectly. Leaf water potentials were never very low even though plants were not irrigated. In old leaves water potential ranged between -0.5 and -0.28 MPa. In young leaves water potential increased with siz…

Routes to cell death in animal and plant kingdoms: from classic apoptosis to alternative ways to die—a review

Programmed cell death is fundamental for multicellular organisms either in animal or plant kingdom. Classic apoptosis, which represents the best studied form of cell death, is dependent on caspase protease activity in animals. These proteases are not present in plants, where caspase-like activities, including metacaspases, are involved in the execution of plant cell death. Beyond apoptosis, various non-apoptotic forms of cell death also exist, including autophagy, necroptosis, pyroptosis, and ferroptosis. These types of cell death can be activated independently of apoptosis and sometimes occur when apoptosis is inhibited. Non-apoptotic forms of cell death are best characterized in animals, …

Effect of Copper, cadmium and chromium on Cyperus alternifolius L. antioxidant systems

Morphological observations on the co-occurring geophytes Isoetes duriei Bory (Lycophyta, Isoetaceae) and Romulea columnae Sebast. et Mauri (Anthophyta, Iridaceae)

Some preliminary observations on the morphoplogy and leaf anatomy of two geophytes, Isoetes duriei and Romulea columnae, co-occurring in a Mediterranean temporary pond, have been reported. The species examined possess characters favourable to the survival of both flooded and arid conditions. The adaptive traits to flooding appear plastic in R. columnae, while I. duriei is “structurally” an aquatic plant. Evolutionary and ecological aspects are briefly discussed.