Apoptotic Potential and Antitumor Efficacy of Trilliumoside A: A New Steroidal Saponin Isolated from Rhizomes of .

Natural product-derived molecules exhibit potential as anticancer agents. Trilliumoside A, a new steroidal saponin, was obtained from rhizomes of , and its anticancer activity was investigated in the presented study. Trilliumoside A was investigated in a panel of cell lines, and it exhibited promising cytotoxic activity on the A549 cells (human lung cancer cells) with an IC of 1.

RecruitNet: A global database of plant recruitment networks.

Plant recruitment interactions (i.e., what recruits under what) shape the composition, diversity, and structure of plant communities.

Simulated nitrogen deposition influences soil greenhouse gas fluxes in a Mediterranean dryland.

Soil nitrogen (N) availability is a key driver of soil-atmosphere greenhouse gas (GHG) exchange, yet we are far from understanding how increases in N deposition due to human activities will influence the net soil-atmosphere fluxes of the three most important GHGs: nitrous oxide (NO), methane (CH) and carbon dioxide (CO). We simulated four levels of N deposition (10, 20 and 50 kg N ha yr, plus unfertilised control) to evaluate their effects on NO, CH and CO soil fluxes in a semiarid shrubland in central Spain. After 8 years of experimental fertilisation, increasing N availability led to a consistent increase in NO emissions, likely due to simultaneous increases in soil microbial nitrification and/or denitrification processes.

Long-term simulated nitrogen deposition alters the plant cover dynamics of a Mediterranean rosemary shrubland in Central Spain through defoliation.

Nitrogen (N) deposition due to anthropogenic pollution is a major driver of the global biodiversity loss. We studied the effect of experimental N and phosphorus (P) fertilization (0, 10, 20, and 50 kg N ha year and 14 kg P ha year over the background deposition levels) on plant cover dynamics of a rosemary (Rosmarinus officinalis L.) shrubland after 8 years of nutrient addition in a semiarid Mediterranean ecosystem from Central Spain.

Contrasting effects of nitrogen addition on soil respiration in two Mediterranean ecosystems.

Increased atmospheric nitrogen (N) deposition is known to alter ecosystem carbon source-sink dynamics through changes in soil CO fluxes. However, a limited number of experiments have been conducted to assess the effects of realistic N deposition in the Mediterranean Basin, and none of them have explored the effects of N addition on soil respiration (R ). To fill this gap, we assessed the effects of N supply on R dynamics in the following two Mediterranean sites: Capo Caccia (Italy), where 30 kg ha year was supplied for 3 years, and El Regajal (Spain), where plots were treated with 10, 20, or 50 kg N ha year for 8 years.

Biogeochemical indicators of elevated nitrogen deposition in semiarid Mediterranean ecosystems.

Nitrogen (N) deposition has doubled the natural N inputs received by ecosystems through biological N fixation and is currently a global problem that is affecting the Mediterranean regions. We evaluated the existing relationships between increased atmospheric N deposition and biogeochemical indicators related to soil chemical factors and cryptogam species across semiarid central, southern, and eastern Spain. The cryptogam species studied were the biocrust-forming species Pleurochaete squarrosa (moss) and Cladonia foliacea (lichen).

Nitrogen deposition alters nitrogen cycling and reduces soil carbon content in low-productivity semiarid Mediterranean ecosystems.

Anthropogenic N deposition poses a threat to European Mediterranean ecosystems. We combined data from an extant N deposition gradient (4.3-7.

Soil chemistry and fertility alterations in response to N application in a semiarid Mediterranean shrubland.

N deposition is currently affecting nutrient cycling in terrestrial ecosystems. We studied the effects of four years of N application (0, 10, 20 and 50 kg N ha(-1) year(-1)+background deposition) on soil chemistry and fertility in a semiarid shrubland in central Spain. Soil pH and nutrient availability fluctuated seasonally.

Forest restoration in a fog oasis: evidence indicates need for cultural awareness in constructing the reference.

Background: In the Peruvian Coastal Desert, an archipelago of fog oases, locally called lomas, are centers of biodiversity and of past human activity. Fog interception by a tree canopy, dominated by the legume tree tara (Caesalpinia spinosa), enables the occurrence in the Atiquipa lomas (southern Peru) of an environmental island with a diverse flora and high productivity. Although this forest provides essential services to the local population, it has suffered 90% anthropogenic reduction in area.

Nitrogen deposition effects on Mediterranean-type ecosystems: an ecological assessment.

We review the ecological consequences of N deposition on the five Mediterranean regions of the world. Seasonality of precipitation and fires regulate the N cycle in these water-limited ecosystems, where dry N deposition dominates. Nitrogen accumulation in soils and on plant surfaces results in peaks of availability with the first winter rains.

Effects of nitrogen deposition and soil fertility on cover and physiology of Cladonia foliacea (Huds.) Willd., a lichen of biological soil crusts from Mediterranean Spain.

We are fertilizing a thicket with 0, 10, 20 and 50 kg nitrogen (N) ha(-1) yr(-1) in central Spain. Here we report changes in cover, pigments, pigment ratios and FvFm of the N-tolerant, terricolous, lichen Cladonia foliacea after 1-2 y adding N in order to study its potential as biomarker of atmospheric pollution. Cover tended to increase.

Nitrogen fixation persists under conditions of salt stress in transgenic Medicago truncatula plants expressing a cyanobacterial flavodoxin.

Several recent studies have demonstrated that the expression of a cyanobacterial flavodoxin in plants can provide tolerance to a wide range of environmental stresses. Indeed, this strategy has been proposed as a potentially powerful biotechnological tool to generate multiple-tolerant crops. To determine whether flavodoxin expression specifically increased tolerance to salt stress and whether it might also preserve legume nitrogen fixation under saline conditions, the flavodoxin gene was introduced into the model legume Medicago truncatula.

Phenotypic plasticity and integration across the canopy of Olea europaea subsp. guanchica (Oleaceae) in populations with different wind exposures.

Woody plants, as sessile and long-lived organisms, are expected to have effective mechanisms for dealing with recurrent environmental stresses. In the present study, we hypothesized that phenotypic plasticity (the ability to express alternative phenotypes) and integration (covariation among functionally related traits) are elicited in plants under stressful wind speed conditions. We investigated the within-crown variation of nine vegetative traits of a tree species (Olea europaea subsp.

Alternative methods for sampling and preservation of photosynthetic pigments and tocopherols in plant material from remote locations.

Current methods for the study of pigments involve freezing in liquid nitrogen and storage at -80 degrees C or lyophilization until HPLC analysis. These requirements greatly restrict ecophysiological research in remote areas where such resources are hardly available. We aimed to overcome such limitations by developing several techniques not requiring freezing or lyophilization.

Field patterns of leaf plasticity in adults of the long-lived evergreen Quercus coccifera.

Background And Aims: Quercus coccifera, as a long-lived sprouter, responds plastically to environmental variation. In this study, the role of foliar plasticity as a mechanism of habitat selection and modification within the canopy and across contrasted habitats was characterized. An examination was made of the differential contribution of inner and outer canopy layers to the crown plasticity expressed in the field by adult individuals and its dependence on environmental and genetic factors.

Plasticity, instability and canalization: is the phenotypic variation in seedlings of sclerophyll oaks consistent with the environmental unpredictability of Mediterranean ecosystems?

•   Evergreen oaks from the Mediterranean basin exhibit a conservative resource-use strategy based on a reduced expression of phenotypic variation (i.e. canalization).

Low leaf-level response to light and nutrients in Mediterranean evergreen oaks: a conservative resource-use strategy?

We have explored leaf-level plastic response to light and nutrients of Quercus ilex and Q. coccifera, two closely related Mediterranean evergreen sclerophylls, in a factorial experiment with seedlings. Leaf phenotypic plasticity, assessed by a relative index (PI = (maximum value - minimum)/maximum) in combination with the significance of the difference among means, was studied in 37 morphological and physiological variables.

Potential effects of rising tropospheric concentrations of CO and O on green-algal lichens.

Pormelia sulcata Taylor was used as a model to examine the effects of elevated CO and/or O on green algal lichens. Thalli were exposed for 30 d in duplicate controlled-environment chambers to two atmospheric concentrations of CO ('ambient' [350μmol mol ] and 'elevated' [700μmol mol ] 24 h d ) and two O regimes ('non-polluted' air [CF, < 5 nmol mol ] and 'polluted' air [15 nmol mol overnight rising to a midday maximum of 75 nmol mol ]), in a factorial design. Elevated CO , or elevated O depressed the light saturated rate of CO , assimilation A ) measured at ambient CO , by 30% and 18%, respectively.