A role for peroxisomes in photomorphogenesis and development of Arabidopsis

The nuclear protein DET1 is a central repressor of photomorphogenesis in plants. We have identified the molecular lesion in ted3, a mutation that dominantly suppresses the phenotypes of det1-1. TED3 encodes a peroxisomal protein (AtPex2p) essential for Arabidopsis growth. Developmental defects and the abnormal expression of many genes in det1 are rescued by ted3. ted3 also partially suppresses another pleiotropic de-etiolated mutant cop1. Thus, peroxisomes, whose functions are still largely unexplored, play a key role in a photomorphogenetic pathway negatively regulated by the DET1 and COP proteins.     

Brominated compounds from marine sponges of the genus Aplysina and a compilation of their 13C NMR spectral data

Aplysina is the best representative genus of the family Aplysinidae. Halogenated substances are its main class of metabolites. These substances contribute greatly to the chemotaxonomy and characterization of the sponges belonging to this genus. Due to their pharmacological activities, these alkaloids are of special interest. The chemistry of halogenated substances and of the alkaloids has long been extensively studied in terrestrial organisms, while the number of marine organisms studied has just started to increase in the last decades. This review describes 101 halogenated substances from 14 species of Aplysina from different parts of the world. These substances can be divided into the following classes: bromotyramines (A), cavernicolins (B), hydroverongiaquinols (C), bromotyrosineketals (D), bromotyrosine lactone derivatives (E), oxazolidones (F), spiroisoxazolines (G), verongiabenzenoids (H), verongiaquinols (I), and dibromocyclohexadienes (J). A compilation of their (13)C NMR data is also part of the review. For this purpose 138 references were consulted.     

Enhanced productivity of a lutein-enriched novel acidophile microalga grown on urea

Coccomyxa acidophila is an extremophile eukaryotic microalga isolated from the Tinto River mining area in Huelva, Spain. Coccomyxa acidophila accumulates relevant amounts of β-carotene and lutein, well-known carotenoids with many biotechnological applications, especially in food and health-related industries. The acidic culture medium (pH < 2.5) that prevents outdoor cultivation from non-desired microorganism growth is one of the main advantages of acidophile microalgae production. Conversely, acidophile microalgae growth rates are usually very low compared to common microalgae growth rates. In this work, we show that mixotrophic cultivation on urea efficiently enhances growth and productivity of an acidophile microalga up to typical values for common microalgae, therefore approaching acidophile algal production towards suitable conditions for feasible outdoor production. Algal productivity and potential for carotenoid accumulation were analyzed as a function of the nitrogen source supplied. Several nitrogen conditions were assayed: nitrogen starvation, nitrate and/or nitrite, ammonia and urea. Among them, urea clearly led to the best cell growth (~4 × 10(8) cells/mL at the end of log phase). Ammonium led to the maximum chlorophyll and carotenoid content per volume unit (220 μg·mL(·1) and 35 μg·mL(·1), respectively). Interestingly, no significant differences in growth rates were found in cultures grown on urea as C and N source, with respect to those cultures grown on nitrate and CO(2) as nitrogen and carbon sources (control cultures). Lutein accumulated up to 3.55 mg·g(·1) in the mixotrophic cultures grown on urea. In addition, algal growth in a shaded culture revealed the first evidence for an active xanthophylls cycle operative in acidophile microalgae.     

Development of an innovative conceptual model and a tiered testing strategy for the ecological risk assessment of rice pesticides

Rice paddies constitute a very special agrobiosystem, which for some circumstances, could be considered as a human driven wetland. The complexity of such dynamic systems is a key element for conducting ecological risk assessments, in addition, the proximity of rice paddies to areas of high ecological value must be considered. This paper presents a new conceptual model for conducting ecological risk assessments of pesticides and other agrochemicals in rice, based on a combination of three main elements, the source of the stressor, the exposed environmental compartments and the relevance of the ecological receptors. A tiered testing strategy, starting with the standard requirements for pesticides and moving to specific higher tier studies with three levels of risk refinement is also presented.     

Grass-induced changes in properties of soils in urban green areas with emphasis on mobility of metals

Purpose

Green areas in urban parks are special ecosystems because of social and ecological benefits.

Materials and methods

We investigated the ecological impacts of green spaces by comparing the properties of soils, with emphasis on metals, in green spaces and bare soil playgrounds in four urban parks in Murcia City (SE Spain).

Results and discussion

Organic matter (OM) contents in green areas are higher than playground soils due to litter decomposition from grass. Cation exchange capacity in green areas ranged from 10 to 14 compared to 2 cmol₊kg^?1 in playground soils, showing the effect of OM (and clay) contents in green areas due to the presence of vegetation. Soil total metal contents in urban parks are below the environmental threshold values for soils in Spain and other European countries, and come from atmospheric deposition and fertilizers application. Diethylenetriaminepentaacetic acid (DTPA)-extractable soil Cd in green areas (4% of total Cd) is lower than in playground soils (58% of total Cd). We attributed the reduced DTPA- and water-extractable Cd, Co, Cr, Mn, and Mo to the formation of stable complexes between metals and OM produced from the continued decomposition of roots of grasses in green spaces.

Conclusions

Grasses accumulate less metal than soils except in roots where Cr and Zn are higher than soils by as much as 31 and 17%, respectively. We conclude that grasses increased (up to 8×) soil OM content in green areas to significantly increase the ability of soils to accumulate nutrients for plants, and to retain and reduce the mobility and toxicity of metals in soils in urban parks.     

Declines in biodiversity and the abundance of pest species across land use gradients in Southeast Asia

Context

Changes in land use have disruptive effects on community structure, causing many species to disappear, though a few thrive and become pests.

Objectives

To gain understanding on how anthropogenic activity changes spatial patterns of native species diversity while favoring pests, we conducted rapid biodiversity assessments of dacine fruit flies across eight regions in Southeast Asia.

Methods

Male lure traps were maintained for 2 days along transects at 233 sites, in forest, agricultural and urban environments.

Results

A total of 8393 individuals were collected, belonging to 57 described and 4 new or unidentified species. The majority (78 %) of individuals belonged to 14 pest species, dominated by Bactrocera dorsalis (Hendel). The 57 species represent 38 % of those recorded from the region, indicating effective sampling. Individual flies were collected in highest numbers in urban and agricultural sites, but species diversity was low. Forest samples yielded fewer specimens but highest species diversity, suggesting a shift in community structure after disturbance, benefiting a few pest species at the expense of the broader community, even in the same genus and ecological guild.

Conclusions

Dacine fruit flies may be useful in assessing habitat quality and bait systems permit the execution of rapid biodiversity and multi-species conservation assessments. Our results apply to broader patterns concerning biodiversity loss and the emergence of pest species under increasingly intensive land use gradients, and demonstrate the remarkable loss of biodiversity over very narrow distances as forest is converted into agricultural use, hence the importance in maintaining a mosaic of native habitats.

     

Effect of dietary vitamin A on Senegalese sole (Solea senegalensis) skeletogenesis and larval quality

The effects of different levels of vitamin A (VA) in Senegalese sole larval performance and development were evaluated by means of a dietary dose–response experiment using enriched Artemia metanauplii as a carrier of this micronutrient. Larvae were fed from 6 to 27 days post hatch (dph) with enriched Artemia containing graded levels of total VA (1.3, 2.1, 4.5 and 12.9 µg VA mg^− 1 DW). The content of VA in live prey directly affected its accumulation in larvae and early juveniles. Retinyl palmitate accumulated during larval ontogeny, whereas retinol showed the opposite trend, decreasing from hatching until 41 dph and then remaining constant until the end of the study.In metamorphic larvae (10 and 15 dph), VA did not affect the number of thyroid follicles or the intensity of the immunoreactive staining of T₃ and T₄. However, at older stages of development (post-metamorphic larvae: 20, 30, 41 and 48 dph), VA decreased the number of thyroid follicles but increased their mean size and enhanced T₃ and T₄ immunoreactive staining. A dietary excess of VA did not affect either larval performance in terms of growth and survival or the maturation of the digestive system. However, the most remarkable impact of this morphogenetic nutrient was detected during skeletal morphogenesis. Dietary VA accelerated the intramembranous ossification of vertebral centrums, which led to the formation of a supranumerary haemal vertebra and a high incidence of fused and compressed vertebrae in fish fed 2.1, 4.5 and 12.9 mg VA mg^− 1 DW. In addition, VA also affected those structures from vertebrae and caudal fin formed by chondral ossification, leading to defects in their shape and fusions with adjacent skeletal elements. In particular, the caudal fin was the region most affected by the dietary treatments. In order of importance, the bones with more developmental anomalies were the modified neural and haemal spines, epural, hypurals and parahypural. The impact of systemic factors such as thyroidal hormones in skeletogenesis should not be neglected since present results revealed that an excess of dietary VA affected the levels of T₃ and T₄, which might have affected bone formation and remodelling, leading to skeletal deformities.     

Comparison of artificial neural network models and empirical and semi-empirical equations for daily reference evapotranspiration estimation in the Basque Country (Northern Spain)

Reference evapotranspiration (ETo) determination is a key factor for water balance and irrigation scheduling. Evapotranspiration can be measured directly by high-cost micrometeorological techniques, or estimated by mathematical models. The combination equation of Penman–Monteith, modified by Allen et al. [Allen, R.G., Pereira, L.S., Raes, D., Smith, M., 1998. Crop evapotranspiration. Guidelines for computing crop water requirements. FAO Irrigation and Drainage, Paper no. 56. FAO, Rome] (PM56), is the reference equation for ETo estimation. This method is also appropriate for the calibration of other ETo estimation equations. The utilization of these calibrated ETo equations is recommended in the absence of data of any of the meteorological parameters necessary for the application of PM56. In addition to the use of classic ETo equations, the adoption of artificial neural network (ANN) models for the estimation of daily ETo has been evaluated in this study. ANNs are mathematical models, whose architecture has been inspired by biological neural networks. They are highly appropriate for the modelling of non-linear processes, which is the case of the evapotranspiration process. Seven ANNs (with different input combinations) have been implemented and compared with ten locally calibrated empirical and semi-empirical ETo equations and variants of these equations (with estimated meteorological parameters as inputs). The comparisons have been based on statistical error techniques, using PM56 daily ETo values as a reference. ANNs have obtained better results than the locally calibrated ETo equations in the three groups of evaluated methods: temperature and/or relative humidity-based methods (0.385 mm d⁻¹ of root mean square error (RMSE)), solar radiation-based methods (0.238 mm d⁻¹ of RMSE), and methods based on similar requirements to those of PM56 except for the estimation of solar radiation and/or relative humidity (0.285 mm d⁻¹ of RMSE).     

Development of a method for the quantitation of chloro-, bromo-, and iodoacetic acids in alcoholic beverages

Chloroacetic, bromoacetic, and iodoacetic acids can be found in alcoholic beverages when they are used as preservatives/stabilizers or as disinfectants. As they are toxic components, their addition is not permitted under European Union and U.S. regulations. To date, no sensitive methods are available, and those proposed are very laborious. This paper describes a sensitive and straightforward method for the determination of the three monohalogenated acetic acids (m-HAAs) in wines and beers using static headspace extraction coupled with gas chromatography-mass spectrometry. Prior to extraction, the target analytes were esterified to increase their volatility, and all parameters related to the extraction/methylation process were optimized to achieve high efficiency (>90%). The study examined the influence both of the ethanol concentration on the headspace partitioning and of the primary acids present in wine on the derivatization reaction of the m-HAAs. The proposed method allows the determination of these compounds at microgram per liter levels in alcoholic beverages.     

Carbon Life Cycle Assessment for Prairie as a Crop in Reclaimed Mine Land

A life cycle assessment with carbon (C) as the reference unit was used to balance the benefits of land preparation practices of establishing tall‐grass prairies as a crop for reclaimed mine land with reduced environmental damage. Land preparation and management practices included disking with sub‐soiling (DK‐S), disking only (DK), no tillage (NT), and no tillage with grazing (NT‐G). To evaluate the C balance and energy use of each of the land preparations, an index of sustainability (I_s = C_O/C_I, Where: C_O is the sum of all outputs and C_I is the sum of all inputs) was used to assess temporal changes in C. Of the four land preparation and management practices, DK had the highest I_s at 8·53. This was due to it having the least degradation of soil organic carbon (SOC) during land‐use change (−730 kg ha⁻¹ y⁻¹) and second highest aboveground biomass production (9,881 kg ha⁻¹). The highest aboveground biomass production occurred with NT (11,130 kg ha⁻¹), although SOC losses were similar to DK‐S, which on average was 2,899 kg ha⁻¹ y⁻¹. The I_s values for NT and DK‐S were 2·50 and 1·44, respectively. Grazing from bison reduced the aboveground biomass to 8,971 kg ha⁻¹ compared with NT with no grazing, although stocking density was low enough that I_s was still 1·94. This study has shown that converting from cool‐season forage grasses to tall‐grass prairie results in a significant net sink for atmospheric CO₂ 3 years after establishment in reclaimed mine land, because of high biomass yields compensating for SOC losses from land‐use change. Copyright © 2014 John Wiley & Sons, Ltd.