Sulfur affects root growth and improves nitrogen recovery and internal efficiency in wheat

Wheat plants were cultivated in pots with the objective of evaluating the effect of two sulfur (S) rates (+S and ?S) on (i) shoot growth, S and nitrogen (N) uptake and nitrogen use efficiency (NUE) and (ii) root growth and architecture and its relations with S and N uptake. Plant samplings were at Z39, Z51 and Z92 stages. Shoot mass and NUE were greater in +S treatment at the three stages. ?S treatment increased root growth at Z39 (14% more length and 16% more tips) in comparison with +S, but the opposite occurred at Z51 (31% less area and 42% less mass). S uptake per unit root mass, area and length were greater in +S treatment at Z39 and Z51. A similar pattern was determined for nitrogen uptake (Nu) at Z39, but the opposite occurred at Z51. This indicates that Nu is mainly controlled by shoot growth and not by root growth.     

Combined Effects of UVR and Temperature on the Survival of Crab Larvae (Zoea I) from Patagonia: The Role of UV-Absorbing Compounds

The aim of our study was to assess the combined impact of UVR (280–400 nm) and temperature on the first larval stage (Zoea I) of three crab species from the Patagonian coast: Cyrtograpsus altimanus, C. angulatus, and Leucippa pentagona. We determined the survival response of newly hatched Zoea I after being exposed for 8–10 h under a solar simulator (Hönle SOL 1200) at 15 and 20 °C. There was no mortality due to Photosynthetic Active Radiation (PAR, 400–700 nm) or ultraviolet-A radiation (UV-A, 315–400 nm), and all the observed mortality was due to ultraviolet-B radiation (UV-B, 280–315 nm). The data of larval mortality relative to exposure time was best fit using a sigmoid curve. Based on this curve, a threshold (Th) and the lethal dose for 50% mortality (LD₅₀) were determined for each species. Based on the Th and LD₅₀, C. altimanus was found to be the most resistant species, while L. pentagona was found to be the most sensitive to UV-B. For both species of Cyrtograpsus, mortality was significantly lower at 20 °C than at 15 °C; however, no significant differences between the two temperature treatments were found in L. pentagona. Bioaccumulation of UV-absorbing compounds in the gonads and larvae of C. altimanus, and to a lesser extent in C. angulatus, might have contributed for counteracting the impact of UV-B. However, most of the resilience to UV-B observed with the increase in temperature might be due to an increase in metabolic activity caused by a repair mechanism mediated by enzymes.     

Designing a hedgerow network in a multifunctional agricultural landscape: Balancing trade-offs among ecological quality,landscape character and implementation costs

Spatial planning aimed at multifunctional agriculture can be seen as a negotiation process on environmental, social and economic aspects of land use. Complexity arises due to the high number of stakeholders and due to the limited knowledge, which is often organized along disciplinary divides. This paper sets out from the premise that the role of agronomy in such land use planning processes can be strengthened by approaches that allow multi-objective and multi-scale evaluation of spatially explicit land use alternatives. We present an application of the explorative Landscape IMAGES framework, which employs the Differential Evolution optimization strategy and the concepts of Pareto optimality that are relatively easy to implement and to combine with spatially explicit indicator assessments. This technique yields a set of solutions, each representing a spatial configuration of hedgerows in a landscape along with the performance of the landscape in terms of Pareto rank and efficiency. The methodology was applied in a redesign of the structure of linear landscape elements in an agri-ecological zone in The Netherlands where 7 indicators representing ecological quality, landscape character and implementation costs were considered. The case study was developed in interaction with an NGO involved in landscape management planning and implementation.Spatial cohesion in the landscape was found to increase with larger total hedgerow length, but could also be improved without increasing the total length (and therefore costs of establishment and maintenance). Trade-offs existed with other objectives, since this change would involve replacing hedgerows currently positioned in the longitudinal direction (L) of the fields by hedgerows in the transversal direction (T). This change would compromise cultural heritage value as expressed in the L/T ratio, and it would require removal of mature hedgerows in some places and adding of new hedgerows elsewhere in the landscape, thereby increasing implementation costs.The approach was evaluated positively in terms of design validity, output validity and end-user validity. The role of the Landscape IMAGES framework in setting a research agenda to enhance the role of agronomy in multifunctional land use planning is discussed.     

Pathogenicity determinants in smut fungi revealed by genome comparison

Biotrophic pathogens, such as the related maize pathogenic fungi Ustilago maydis and Sporisorium reilianum, establish an intimate relationship with their hosts by secreting protein effectors. Because secreted effectors interacting with plant proteins should rapidly evolve, we identified variable genomic regions by sequencing the genome of S. reilianum and comparing it with the U. maydis genome. We detected 43 regions of low sequence conservation in otherwise well-conserved syntenic genomes. These regions primarily encode secreted effectors and include previously identified virulence clusters. By deletion analysis in U. maydis, we demonstrate a role in virulence for four previously unknown diversity regions. This highlights the power of comparative genomics of closely related species for identification of virulence determinants.     

Pseudo-placentational Endometrial Cysts in a Bitch

Cystic alterations of the canine endometrium compromise reproduction and fertility of the bitch and may lead to life-threatening diseases, such as pyometra. Even without clinical evidence, reduction of the uterine lumen by cysts implicates disturbances during migration, nidation and development of the embryo. Several studies point to the high variability of morphology of uterine endometrial cysts but they lack detailed analyses of alterations. In the present study, immunohistochemistry was used to investigate the expression of steroid hormone receptors (oestrogen, progesterone), proliferation activity, inflammation and infection in the cystic affected tissue regions in contrast to the normal endometrium. Oestrogen receptor expression showed a high density of receptors throughout the surface epithelial cells, crypt epithelial cells, glandular epithelial cells and stromal cells of the normal endometrium as well as the cystic affected regions. Proliferation in the cysts was verified in the middle and basal cells of the crypts. Neither in the endometrium nor in the cysts inflammatory processes or evidence of infection could be detected. Furthermore, lectin histochemistry and electron microscopic methods showed that lectin binding patterns and cell morphology of internal epithelial lining and surface epithelium of the cysts can be used to characterize and distinguish different types of cystic alterations. Analogies between epithelial cells of the glandular chambers of the canine placenta and the cystic cellular morphology, steroid hormone receptor distribution as well as lectin binding patterns of the endometrial cysts, as observed in this study, suggest to introduce the term 'pseudo-placentational endometrial cysts'.     

The essential oil of Eucalyptus tereticornis, and its constituents α- and β-pinene,potentiate acetylcholine-induced contractions in isolated rat trachea

The effects of the essential oil of Eucalyptus tereticornis (EOET), especially the effects of its constituents α- and β-pinene, were studied on rat trachea in vitro. In tracheal rings, EOET, α- or β-pinene potentiated the contractions induced by acetylcholine (ACh). Contractions induced by K⁺ (60 mM) were also potentiated by α- and β-pinene, but were reduced by EOET. Our findings show that EOET has myorelaxant effects on rat airways, but potentiates ACh-induced contractions. Monoterpenes α- and β-pinene are involved in its potentiating actions, but are not responsible for its myorelaxant effects. A putative inhibition of the acetylcholinesterase enzyme is involved.     

Designing agricultural landscapes for natural pest control: a transdisciplinary approach in the Hoeksche Waard (The Netherlands)

The green–blue network of semi-natural non-crop landscape elements in agricultural landscapes has the potential to enhance natural pest control by providing various resources for the survival of beneficial insects that suppress crop pests. A study was done in the Hoeksche Waard to explore how generic scientific knowledge about the relationship between the spatial structure of the green–blue network and enhancement of natural pest control can be applied by stakeholders. The Hoeksche Waard is an agricultural area in the Netherlands, characterized by arable fields and an extensive network of dikes, creeks, ditches and field margins. Together with stakeholders from the area the research team developed spatial norms and design rules for the design of a green–blue network that supports natural pest control. The stakeholders represented different interests in the area: farmers, nature and landscape conservationists, water managers, and local and regional politicians. Knowledge about the spatial relationship among beneficial insects, pests and landscape structure is incomplete. We conclude that to apply scientific knowledge about natural pest control and the role of green–blue networks to stakeholders so that they can apply it in landscape change, knowledge transfer has to be transparent, area specific, understandable, practical and incorporate local knowledge.