The meta-hydroxylation step in the phenylpropanoid pathway: a new level of complexity in the pathway and its regulation

Together in silico and genetic mining approaches have recently designated the CYP98 family of plant cytochromes P450 as the family of enzymes that catalyzes the meta-hydroxylation step in the phenylpropanoid pathway. This meta-hydroxylation is not catalyzed on the free p-coumaric acid as anticipated, but on its conjugates with shikimic, quinic, or phenyllactic acids. While all CYP98s have in common phenol meta-hydroxylase activity, p-coumaroylshikimate remains their preferred substrate. High expression of CYP98s is detected in lignifying tissues in stems, roots, and siliques. The CYP98A3 gene disruption in Arabidopsis thaliana leads to a drastic inhibition of lignin synthesis, cell growth, and plant development. The meta-hydroxylation of phenolic precursors is thus essential for higher plant development. Isolation of coding sequences belonging to the CYP98 family from basil, wheat, and extensive functional analysis of the recombinant enzymes, together with CYP98s from other plant taxa, helps shedding some light on mechanisms of P450s evolution. Most importantly, the occurrence of the meta-hydroxylation on esters of shikimic or quinic acids introduces a new biochemical regulation mechanism in the phenylpropanoid pathway.     

Geochemical evaluation of metals in groundwater at long‐term monitoring sites and active remediation sites

At many sites, long‐term monitoring (LTM) programs include metals as chemicals of concern, although they may not be site‐related contaminants and their detected concentrations may be natural. At other sites, active remediation of organic contaminants in groundwater results in changes to local geochemical conditions that affect metal concentrations. Metals should be carefully considered at both types of sites, even if they are not primary contaminants of concern. Geochemical evaluation can be performed at LTM sites to determine if the monitored metals reflect naturally high background and, hence, can be removed from the analytical program. Geochemical evaluation can also be performed pre‐ and post‐treatment at active remediation sites to document the effects of organics remediation on metals and identify the processes controlling metal concentrations. Examples from both types of sites are presented in this article. © 2008 Wiley Periodicals, Inc.     

A priority-ranking strategy for threatened species?

Summary The rate of extinction has accelerated to the point where we are probably losing one species per day right now, and we could well lose one million of Earth's 5–10 million species by the year 2000, and a good many more within the early decades of the next century. Plainly we cannot assist all species that face extinction within the foreseeable future. Conservationists have limited resources at their disposal, in the way of finance, scientific skills, and the like. Even were these resources to be increased several times over, we could not hope to save more than a proportion of all species that appear doomed to disappear: the processes of habitat disruption are too strongly underway to be halted in short order. But when we allocate funds to safeguard one species, we automatically deny those funds to other species. Already we support only a small fraction of all species under threat, and we may soon find ourselves in a situation where we can assist only a very marginal number of species facing extinction. Thus a key question arises: how are we to allocate our scarce resources in the most efficient way to safeguard species? Indeed we may now have reached a stage where there is merit in determining which species are most deserving of a place on the planet. Agonizing as it will be to make choices along these lines, conservation strategy should be as systematically selective as possible. This means that we should design analytic methodologies to enable us to assign our conservation resources to achieve maximum return in terms of numbers of species protected. In essence, a triage strategy. An expanded approach along these lines postulates a quantum advance in our planning of responses to the growing threatened-species problem: while the techniques of the past have certainly helped the situation, we cannot confront the much greater challenges of the future with an attitude of the same as before, only more so—the future will not be a simple extrapolation of the past, but will represent a qualitatively larger set of problems, which require an appropriately scaled-up response in our save-species campaigns.Dr Norman Myers is an expert in the study of endangered species and ecosystems. He is an international consultant in Environment and Development. This paper is based in part on findings of a project that he conducted for the World Wildlife Fund—US, to which grateful acknowledgment is made. The responsibility for all conclusions and recommendations remains, of course, with the author.     

Shoreline management and its implications for coastal processes in the eastern part of the Rhône delta

The coastal fringe of the eastern part of the Rhône delta is a large area where activities related to ecological and economical interests have increased since the beginning of the century, including the salt industry of theCompagnie des Salins du Midi et des Salines de l’Est, the industrial complex ofFos-sur-Mer, tourism managed by the local authorities ofPort-Saint-Louis andArles, and dune restoration of the La Gracieuse spit undertaken by thePort Autonome de Marseille. The vulnerability of the area for changes brought about by these activities is linked to the extent of several coastal changes, whereas these changes are related to the physical functioning of the coastal fringe, such as coastal processes, but also to external components such as relative sea-level rise, subsidence, reduction of sediment input, human impact, etc. For many decades, coastline ‘protection’ in the eastern part of the Rhône delta has been undertaken to withstand erosional processes that offset beaches and retreat of the littoral. The use of different engineering structures illustrates the heterogeneity and differences in age of the various management policies. At the eastern side of the Rhône, thePort Autonome de Marseille, dealing with management, has opted for soft engineering structures using fences for dune restoration on the La Gracieuse spit. At the western side of the mouth, theCompagnie des Salins du Midi et des Salines de l’Est has been using hard engineering structures to combat erosion (rocks, groins, tetrapods, etc.). A brief assessment of the management efficiency is presented, including an analysis of the data collected concerning the survey of the zones where the structures were built. Their varying efficiency shows the important role played by the sediment supply to the littoral (solid river discharge) and the coastal hydro-sedimentary processes. In the eastern part of the Rhône river the success of the dune restoration is mainly due to the important sediment supply transported in this area by eastern drift currents. At the western part of the mouth, the decrease of sediment supply linked to erosional processes in the shallow off-shore beach has made the structures more vulnerable, and therefore, the activities of the salt industry. For this last threatened zone, three management scenarios are discussed by taking into account economical, physical and ecological parameters.     

Injury severity related to overturn characteristics of tractors

Introduction

Early studies of injuries associated with overturns indicate that more fatalities occurred when a tractor overturned beyond 90° (continuous roll) relative to the impact plane. Recently, the principle of preventing continuous rolls has re-emerged for the protection of riding lawnmower operators.

Method

Related to tractors, a population-based study was conducted that compared the severity of fatal and nonfatal injuries between a 90° and continuous roll for tractors equipped with rollover protective structures (ROPS) and not equipped with a ROPS (non- ROPS). In 2002, the Kentucky Farm Tractor Overturn Survey was administered to an 8% random sample (6,063) of Kentucky farm operators. The farmers responded to questions that differentiated between the types of overturns and operator injury outcomes for ROPS-equipped and non-ROPS tractors during overturn events. Overturn characteristics were collected that included 90° to the side, beyond 90° to the side, and to the rear for both ROPS-equipped and non-ROPS tractors.

Results

Of the 541 overturns reported in this study, 535 (99%) of the respondents reported the most recent overturn characteristics of the tractor: 92 (17%) were ROPS-equipped and 443 (83%) were non-ROPS. For side overturns, 67% of the rolls occurred with ROPS-equipped tractors, and 54% occurred with non-ROPS tractors. The percentages of deaths related to rolls to the side for ROPS-equipped and non-ROPS tractors were, respectively, 1.6% and 3.7%. There was one (2%) deaths related to 90° rolls for ROPS-equipped tractors, whereas for continuous rolls there were 6.4% fatalities related to side overturns, 13% resulted in non-fatal injuries with an average of 1 day of hospitalization for ROPS-equipped tractors, and 39% resulted in non-fatal injuries with an average of 18 days of hospitalization for non-ROPS tractors. The results from this study indicated that a ROPS was more effective at stopping an overturn at 90° than no ROPS, with an associated reduction in the severity of injury in the event of a tractor overturn.     

Seasonal variability of antioxidant biomarkers and energy reserves in the freshwater gammarid Gammarus roeseli

In gammarids, behavioural and biochemical biomarkers are commonly used in ecotoxicological studies. In our study, we have investigated seasonal variations of several biochemical biomarkers in Gammarus roeseli, a freshwater species. Organisms were sampled monthly over a 1-year period. Gender was distinguished to measure antioxidant enzyme activities like total glutathione peroxidase (GPxtot), selenium-dependent glutathione peroxidase (SeGPx) and catalase enzymes, lipoperoxidation end-product (malondialdehyde, MDA), and energy reserves with protein and lipid contents. In the same time, usual water physico-chemical parameters were measured at the sampling site. A based-gender difference was observed for parameters related to oxidative stress. Females showed higher antioxidant enzyme activities and lower MDA level than males. Parameters related to oxidative stress and energy reserves appeared correlated with temperature and physiological status of organisms. Females GPx activities were lower in autumn and winter when no breeding occurred. In both gender, MDA levels were correlated with temperature with an increase of lipoperoxidation in summer. Lipid contents were the lowest in summer and the highest in winter, probably due to the reproductive status of organisms and their feeding behaviour. Gender-based differences of biochemical parameters suggest a specific sensitivity of males and females in ecotoxicological experiments. Moreover, organisms could be more vulnerable in summer when MDA levels are high and energy reserves low. Deleterious effect of xenobiotics would be different with gender and season.     

Effect of the Introduced Common Slipper Shell on the Suprabenthic Biodiversity of the Subtidal Communities in the Bay of Saint-Brieuc

Abstract: Our study compared the suprabenthic fauna collected in the Bay of Saint-Brieuc (western English Channel) in September 1995 and May 1996 at two sites colonized by Crepidula fornicata with that of one site where it was absent (site 23–0). Where Crepidula was present, no species dominated and abundance remained low. At the site without Crepidula , abundance was higher and the mysid Haplostylus lobatus dominated the suprabenthic community. Swimming activity of most suprabenthic species was increased by the presence of C. fornicata . The differential abundance and swimming activity of certain species are linked to the conversion of the formerly soft substrate to now hard, shelled substrate.