A prokaryotic origin for light-dependent chlorophyll biosynthesis of plants.

Flowering plants require light for chlorophyll synthesis. Early studies indicated that the dependence on light for greening stemmed in part from the light-dependent reduction of the chlorophyll intermediate protochlorophyllide to the product chlorophyllide. Light-dependent reduction of protochlorophyllide by flowering plants is contrasted by the ability of nonflowering plants, algae, and photosynthetic bacteria to reduce protochlorophyllide and, hence, synthesize (bacterio) chlorophyll in the dark. In this report, we functionally complemented a light-independent protochlorophyllide reductase mutant of the eubacterium Rhodobacter capsulatus with an expression library composed of genomic DNA from the cyanobacterium Synechocystis sp. PCC 6803. The complemented R. capsulatus strain is capable of synthesizing bacteriochlorophyll in the light, thereby indicating that a chlorophyll biosynthesis enzyme can function in the bacteriochlorophyll biosynthetic pathway. However, under dark growth conditions the complemented R. capsulatus strain fails to synthesize bacteriochlorophyll and instead accumulates protochlorophyllide. Sequence analysis demonstrates that the complementing Synechocystis genomic DNA fragment exhibits a high degree of sequence identity (53-56%) with light-dependent protochlorophyllide reductase enzymes found in plants. The observation that a plant-type, light-dependent protochlorophyllide reductase enzyme exists in a cyanobacterium indicates that light-dependent protochlorophyllide reductase evolved before the advent of eukaryotic photosynthesis. As such, this enzyme did not arise to fulfill a function necessitated either by the endosymbiotic evolution of the chloroplast or by multicellularity; rather, it evolved to fulfill a fundamentally cell-autonomous role.

Ethnobotanic importance of plants used in pigeon-breeding in Eastern Spain

Background: The importance that birds of the Columbidae family have had throughout history is visible on the Mediterranean coast. Pigeon fancying is the art of breeding and training carrier pigeons and currently, several breeds exist. The sport of racing pigeons consists in covering a distance at maximum possible speed. However, pigeon breeding has another modality called “sport pigeon”, where several males follow a female. This study focusses on ethnobotanical knowledge of native and exotic plant species that are used for diet, breeding, stimulation, healing illnesses and staining the plumage of pigeons bred in captivity. Methods: Using semi-structured interviews, we gathered information about the different plant species traditionally used for pigeon-breeding in the region of Valencia. Background material on remedies for bird illnesses was gathered from folk botanical references, local books and journals. The plant species were collected in the study area, then identified in the laboratory using dichotomous keys and vouchered in the ABH (Herbarium of Alicante University). We used Excel ® 2003 to perform a simple statistical analysis of the data collected. Results: We collected 56 species of plants (and one variety) that included 29 botanical families. The total number of species was made up of 35 cultivated and 21 wild plants. The most common were Gramineae (14 species), Leguminosae (6 species), and Compositae (4 species). Conclusions: Pigeon breeding is an immensely popular activity in Eastern Spain, and ethnobiological knowledge about breeding pigeons and caring for them is considerable. The names and traditional uses of plants depend on their geographical location, vernacular names serve as an intangible heritage. Feeding, environmental features, and genetic makeup of individuals are relevant aspects in the maintenance of avian health.

Sequencing and functional analysis of the genome of a nematode egg-parasitic fungus, Pochonia chlamydosporia

Pochonia chlamydosporia is a worldwide-distributed soil fungus with a great capacity to infect and destroy the eggs and kill females of plant-parasitic nematodes. Additionally, it has the ability to colonize endophytically roots of economically-important crop plants, thereby promoting their growth and eliciting plant defenses. This multitrophic behavior makes P. chlamydosporia a potentially useful tool for sustainable agriculture approaches. We sequenced and assembled ∼41 Mb of P. chlamydosporia genomic DNA and predicted 12,122 gene models, of which many were homologous to genes of fungal pathogens of invertebrates and fungal plant pathogens. Predicted genes (65%) were functionally annotated according to Gene Ontology, and 16% of them found to share homology with genes in the Pathogen Host Interactions (PHI) database. The genome of this fungus is highly enriched in genes encoding hydrolytic enzymes, such as proteases, glycoside hydrolases and carbohydrate esterases. We used RNA-Seq technology in order to identify the genes expressed during endophytic behavior of P. chlamydosporia when colonizing barley roots. Functional annotation of these genes showed that hydrolytic enzymes and transporters are expressed during endophytism. This structural and functional analysis of the P. chlamydosporia genome provides a starting point for understanding the molecular mechanisms involved in the multitrophic lifestyle of this fungus. The genomic information provided here should also prove useful for enhancing the capabilities of this fungus as a biocontrol agent of plant-parasitic nematodes and as a plant growth-promoting organism.

Conditional Order-m Efficiency of Wastewater Treatment Plants: The Role of Environmental Factors

The growing economic and environmental importance of managing water resources at a global level also entails greater efforts and interest in improving the functioning and efficiency of the increasingly more numerous wastewater treatment plants (WWTPs). In this context, this study analyzes the efficiency of a uniform sample of plants of this type located in the region of Valencia (Spain). The type of efficiency measure used for this (conditional order-m efficiency) allows continuous and discrete contextual variables to be directly involved in the analysis and enables the assessment of their statistical significance and effect (positive or negative). The main findings of the study showed that the quality of the influent water and also the size and age of the plants had a significant influence on their efficiency levels. In particular, as regards the effect of such variables, the findings pointed to the existence of an inverse relationship between the quality of the influent water and the efficiency of the WWTPs. Also, a lower annual volume of treated water and more modern installations showed a positive influence. Additionally, the average efficiency levels observed turned out to be higher than those reported in previous studies.

An ethnopharmacological and historical analysis of “Dictamnus”, a European traditional herbal medicine

Ethnopharmacological relevance and background: “Dictamnus” was a popular name for a group of medicinal herbaceous plant species of the Rutaceae and Lamiaceae, which since the 4th century have been used for gynaecological problems and other illnesses BCE and still appear in numerous ethnobotanical records. Aims: This research has as four overarching aims: Determining the historical evolution of medical preparations labelled “Dictamnus” and the different factors affecting this long-standing herbal tradition. Deciphering and differentiating those medicinal uses of “Dictamnus” which strictly correspond to Dictamnus (Rutaceae), from those of Origanum dictamnus and other Lamiaceae species. Quantitatively assessing the dependence from herbal books, and pharmaceutical tradition, of modern Dictamnus ethnobotanical records. Determining whether differences between Western and Eastern Europe exist with regards to the Dictamnus albus uses in ethnopharmacology and ethnomedicine. Methods: An exhaustive review of herbals, classical pharmacopoeias, ethnobotanical and ethnopharmacological literature was conducted. Systematic analysis of uses reported which were standardized according to International Classification of Diseases – 10 and multivariate analysis using factorial, hierarchical and neighbour joining methods was undertaken. Results and discussion: The popular concept “Dictamnus” includes Origanum dictamnus L., Ballota pseudodictamnus (L.) Benth. and B. acetabulosa (L.) Benth. (Lamiaceae), as well as Dictamnus albus L. and D. hispanicus Webb ex Willk. (Rutaceae), with 86 different types of uses. Between 1000 and 1700 CE numerous complex preparations with “Dictamnus” were used in the treatment of 35 different pathologies. On biogeographical grounds the widespread D. albus is a far more likely prototypical “Dictamnus” than the Cretan endemic Origanum dictamnus. However both form integral parts of the “Dictamnus” complex. Evidence exists for a sufficiently long and coherent tradition for D. albus and D. hispanicus, use to treat 47 different categories of diseases. Conclusions: This approach is a model for understanding the cultural history of plants and their role as resources for health care. “Dictamnus” shows how transmission of traditional knowledge about materia medica, over 26 centuries, represents remarkable levels of development and innovation. All this lead us to call attention to D. albus and D. hispanicus which are highly promising as potential herbal drug leads. The next steps of research should be to systematically analyse phytochemical, pharmacological and clinical evidence and to develop safety, pharmacology and toxicology profiles of the traditional preparations.

(Table A1) Annual biomass of plants and animals recorded on Bylot Island between 1993-2009

Determining the manner in which food webs will respond to environmental changes is difficult because the relative importance of top-down vs. bottom-up forces in controlling ecosystems is still debated. This is especially true in the Arctic tundra where, despite relatively simple food webs, it is still unclear which forces dominate in this ecosystem. Our primary goal was to assess the extent to which a tundra food web was dominated by plant-herbivore or predator--rey interactions. Based on a 17-year (1993-2009) study of terrestrial wildlife on Bylot Island, Nunavut, Canada, we developed trophic mass balance models to address this question. Snow Geese were the dominant herbivores in this ecosystem, followed by two sympatric lemming species (brown and collared lemmings). Arctic foxes, weasels, and several species of birds of prey were the dominant predators. Results of our trophic models encompassing 19 functional groups showed that <10% of the annual primary production was consumed by herbivores in most years despite the presence of a large Snow Goose colony, but that 20-100% of the annual herbivore production was consumed by predators. The impact of herbivores on vegetation has also weakened over time, probably due to an increase in primary production. The impact of predators was highest on lemmings, intermediate on passerines, and lowest on geese and shorebirds, but it varied with lemming abundance. Predation of collared lemmings exceeded production in most years and may explain why this species remained at low density. In contrast, the predation rate on brown lemmings varied with prey density and may have contributed to the high-amplitude, periodic fluctuations in the abundance of this species. Our analysis provided little evidence that herbivores are limited by primary production on Bylot Island. In contrast, we measured strong predator-prey interactions, which supports the hypothesis that this food web is primarily controlled by top-down forces. The presence of allochthonous resources subsidizing top predators and the absence of large herbivores may partly explain the predominant role of predation in this low-productivity ecosystem.

(Table 1) Organic carbon and radiogenic isotopes analysis of DSDP Hole 22-218 sediments

Modern erosion of the Himalaya, the world's largest mountain range, transfers huge dissolved and particulate loads to the ocean. It plays an important role in the long-term global carbon cycle, mostly through enhanced organic carbon burial in the Bengal Fan. To understand the role of past Himalayan erosion, the influence of changing climate and tectonic on erosion must be determined. Here we use a 12 Myr sedimentary record from the distal Bengal Fan (Deep Sea Drilling Project Site 218) to reconstruct the Mio-Pliocene history of Himalayan erosion. We use carbon stable isotopes (d13C) of bulk organic matter as paleo-environmental proxy and stratigraphic tool. Multi-isotopic - Sr, Nd and Os - data are used as proxies for the source of the sediments deposited in the Bengal Fan over time. d13C values of bulk organic matter shift dramatically towards less depleted values, revealing the widespread Late Miocene (ca. 7.4 Ma) expansion of C4 plants in the basin. Sr, Nd and Os isotopic compositions indicate a rather stable erosion pattern in the Himalaya range during the past 12 Myr. This supports the existence of a strong connection between the southern Tibetan plateau and the Bengal Fan. The tectonic evolution of the Himalaya range and Southern Tibet seems to have been unable to produce large re-organisation of the drainage system. Moreover, our data do not suggest a rapid change of the altitude of the southern Tibetan plateau during the past 12 Myr. Variations in Sr and Nd isotopic compositions around the late Miocene expansion of C4 plants are suggestive of a relative increase in the erosion of High Himalaya Crystalline rock (i.e. a simultaneous reduction of both Transhimalayan batholiths and Lesser Himalaya relative contributions). This could be related to an increase in aridity as suggested by the ecological and sedimentological changes at that time. A reversed trend in Sr and Nd isotopic compositions is observed at the Plio-Pleistocene transition that is likely related to higher precipitation and the development of glaciers in the Himalaya. These almost synchronous moderate changes in erosion pattern and climate changes during the late Miocene and at the Plio-Pleistocene transition support the notion of a dominant control of climate on Himalayan erosion during this time period. However, stable erosion regime during the Pleistocene is suggestive of a limited influence of the glacier development on Himalayan erosion.

Analysis of vegetation controls on bank erosion rates, Clark Fork of the Columbia River, Deer Lodge Valley, Montana /

"U.S. Geological Survey, U.S. Department of the Interior"--P. [1].

An analysis of the potentials and prospects of increasing edible oil production in West Pakistan : research conducted in Jan. 1971 /

Mode of access: Internet.

Regional economic impacts of nuclear power plants /

"BNL 50562."

Wisconsin soil testing plant analysis and feed and forage analysis procedures /

"Revised 1977"--cover.

The effect of operating temperature on the cost of energy from solar thermal electric power plants /

"Prepared for the U.S. Dept. of Energy, under contract DE-AC04-76-DP00789."

Institutes of botany : containing accurate, compleat and easy descriptions of all the known genera of plants /

Mode of access: Internet.

Safety analysis of nuclear concrete containment structure /

"NRC FIN no. B5688."