Search

Symbioses with beneficial microbes are widespread in plants, but these relationships must balance the energy invested by the plants with the nutrients acquired. Symbiosis with arbuscular mycorrhizal (AM) fungi occurs throughout land plants but our understanding of the genes and signals that regulate colonisation levels is limited. Here, we demonstrate that in tomato two CLV3/EMBRYO-SURROUNDING REGION (CLE) peptides,SlCLE10 andSlCLE11, act to suppress AM colonisation of roots. Mutant studies and overexpression via hairy transformation indicateSlCLE11acts locally in the root to limit AM colonisation. Indeed,SlCLE11expression is strongly induced in AM colonised roots butSlCLE11is not required for phosphate suppression of AM colonisation.SlCLE11 may act through as yet uncharacterised signalling pathways, asSlCLE11does not suppress AM colonisation by acting through two previously characterised receptors with roles in regulating AM colonisation,SlFAB (CLAVATA1 orthologue) orSlCLV2.SlCLE10 appears to play a more minor or redundant role, ascle10mutants did not influence AM, although the fact that ectopic overexpression ofSlCLE10did suppress colonisation suggestsSlCLE10may play a role in regulating AM colonisation. Our findings show that CLE peptides regulate AM colonisation in the non-legume species tomato.

Two hundred years after the birth of Gregor Mendel, it is an appropriate time to reflect on recent developments in the discipline of genetics, particularly advances relating to the prescient friar’s model species, the garden pea (Pisum sativum L.). Mendel’s study of seven characteristics established the laws of segregation and independent assortment. The genes underlying four of Mendel’s loci (A, LE, I, and R) have been characterized at the molecular level for over a decade. However, the three remaining genes, influencing pod color (GP), pod form (V/P), and the position of flowers (FA/FAS), have remained elusive for a variety of reasons, including a lack of detail regarding the loci with which Mendel worked. Here, we discuss potential candidate genes for these characteristics, in light of recent advances in the genetic resources for pea. These advances, including the pea genome sequence and reverse-genetics techniques, have revitalized pea as an excellent model species for physiological–genetic studies. We also discuss the issues that have been raised with Mendel’s results, such as the recent controversy regarding the discrete nature of the characters that Mendel chose and the perceived overly-good fit of his segregations to his hypotheses. We also consider the relevance of these controversies to his lasting contribution. Finally, we discuss the use of Mendel’s classical results to teach and enthuse future generations of geneticists, not only regarding the core principles of the discipline, but also its history and the role of hypothesis testing.

The underlying mechanisms that determine whether two species can form a successful graft union (graft compatibility) remain obscure. Two prominent hypotheses are (1) the more closely related species are, the higher the graft success and (2) the vascular anatomy at the graft junction influences graft success. In this paper these two hypotheses are examined in a systematic way using graft combinations selected from a range of (a) phylogenetically close and more distant legume species, (b) species displaying different germination patterns and (c) scions and rootstocks possessing contrasting stem tissues and vascular patterns. Relatedness of species was not a good predictor of graft compatibility, as vascular reconnection can occur between distantly related species and can fail to occur in some more closely related species. Similarly, neither the stem tissues present at the graft junction nor the vascular anatomy correlated with the success of vascular reconnection. Relatedness and stem anatomy therefore do not appear to be the determining factors in successful vascular reconnection after grafting in legumes. These results are discussed in conjunction with other hypotheses such as the role of auxin.

In coal mining it is important to know if localised areas of coal have been rendered worthless through direct contact with volcanic intrusions. To avoid dilution, accurate coked coal boundaries are...

The Darlot gold mine is an Archean orogenic deposit located in the world-class gold and nickel terrain of the Yandal granite-greenstone belt, part of the Yilgarn Craton in Western Australia.A 3D se...

MOTIVATION: We undertook large citizen science surveys of bird distributions (atlases) in Britain and Ireland, aimed at quantifying breeding bird distributions on a 20‐year cycle and wintering bird distributions on a c. 30‐year cycle. We use these to generate spatially referenced information on apparent changes in bird distributions over c. 40 years. MAIN TYPE OF VARIABLE CONTAINED: Detection of breeding and wintering bird species in grid squares during five periods, and changes in detection between periods. The combined distribution dataset contains 1,410,938 records detailing detections of 465 bird species in 3,880 grid cells in different periods. The combined distribution change dataset contains 1,297,791 records describing stability, apparent colonization or apparent extinction of individual species in grid squares between pairs of atlases spanning up to c. 40 years. SPATIAL LOCATION AND GRAIN: Grid squares (10 km × 10 km) containing land throughout Britain, Ireland, the Isle of Man and the Channel Islands. The majority of data are at 10‐km resolution, but data for rare species are summarized at 20‐ or 50‐km resolution to protect sensitive locations. TIME PERIOD: The data represent summarized detection information derived from fieldwork during five periods: the breeding seasons 1968–1972, 1988–1991 and 2008–2011, and the winters 1981/1982–1983/1984 and 2007/2008–2010/2011. MAJOR TAXA STUDIED AND LEVEL OF MEASUREMENT: Birds; their distribution derived from citizen science surveys. SOFTWARE FORMAT: Data are supplied as comma‐separated text files.

Plants form mutualistic nutrient-acquiring symbioses with microbes, including arbuscular mycorrhizal fungi. The formation of these symbioses is costly, and plants employ a negative feedback loop termed autoregulation of mycorrhizae (AOM) to limit formation of arbuscular mycorrhizae (AM). We provide evidence for the role of one leucine-rich repeat receptor-like kinase (FAB), a hydroxyproline O-arabinosyltransferase enzyme (FIN), and additional evidence for one receptor-like protein (SlCLV2) in the negative regulation of AM formation in tomato. Reciprocal grafting experiments suggest that the FAB gene acts locally in the root, while the SlCLV2 gene may act in both the root and the shoot. External nutrients including phosphate and nitrate can also strongly suppress AM formation. We found that FAB and FIN are required for nitrate suppression of AM but are not required for the powerful suppression of AM colonization by phosphate. This parallels some of the roles of legume homologues in the autoregulation of the more recently evolved symbioses with nitrogen-fixing bacteria leading to nodulation. This deep homology in the symbiotic role of these genes suggests that in addition to the early signalling events that lead to the establishment of AM and nodulation, the autoregulation pathway might also be considered part of the common symbiotic toolkit that enabled plants to form beneficial symbioses.

Plants use a variety of hormonal and peptide signals to control root development, including in adapting root development to cope with nutrient stress. Nitrogen (N) is a major limiting factor in plant growth and in response to N stress plants dramatically modulate root development, including in legumes influencing the formation of N-fixing nodules in response to external N supply. Recently, specific CLE peptides and/or receptors important for their perception, including CLV1 and CLV2, have been found to play important roles in root development in a limited number of species, including in some cases the response to N. In the legume Medicago truncatula, this response also appears to be influenced by RDN1, a member of the hydroxyproline O-arabinosyltransferase (HPAT) family which can modify specific CLE peptides. However, it not known if this signalling pathway plays a central role in root development across species, in particular root responses to N. In this study, we sought to systematically examine the role of homologues of these genes in root development of the legume pea (Pisum sativum. L) and non-legume tomato (Solanum lycopersicum) using a mutant based approach. This included a detailed examination of root development in response to N in these mutant series in tomato. We found no evidence for a role of these genes in pea seedling root development. Furthermore, the CLV1-like FAB gene did not influence tomato root development, including N response. In contrast, both CLV2 and the HPAT FIN appear to positively influence root size in tomato but do not mediate root responses to N. These suggest a relatively species-specific role for these genes in root development, including N regulation of root architecture.

Plants form mutualistic nutrient acquiring symbioses with microbes, including arbuscular mycorrhizal fungi. The formation of these symbioses is costly and plants employ a negative feedback loop termed autoregulation of mycorrhizae (AOM) to limit arbuscular mycorrhizae (AM) formation. We provide evidence for the role of one leucine-rich-repeat receptor like kinase (FAB), a hydroxyproline O-arabinosyltransferase enzyme (FIN) and additional evidence for one receptor like protein (SlCLV2) in the negative regulation of AM formation in tomato. Reciprocal grafting experiments suggest that the FAB gene acts locally in the root, while the SlCLV2 gene may act in both the root and the shoot. External nutrients including phosphate and nitrate can also strongly suppress AM formation. We found that FAB and FIN are required for nitrate suppression of AM but are not required for the powerful suppression of AM colonisation by phosphate. This parallels some of the roles of legume homologs in the autoregulation of the more recently evolved symbioses with nitrogen-fixing bacteria leading to nodulation. This deep homology in the symbiotic role of these genes suggests that in addition to the early signalling events that lead to the establishment of AM and nodulation, the autoregulation pathway might also be considered part of the common symbiotic toolkit that enabled plants to form beneficial symbioses.HighlightWe describe the role of CLV signalling elements in the negative regulation of arbuscular mycorrhizal symbioses of tomato, including influencing nitrate but not phosphate suppression of mycorrhizal colonisation.

Plants use a variety of signals to control root development, including in modifying root development in response to nutrient stress. For example, in response to nitrogen (N) stress, plants dramatically modulate root development, including the formation of N-fixing nodules in legumes. Recently, specific CLE peptides and/or receptors important for their perception, including CLV1 and CLV2, have been found to play roles in root development, including in response to N supply. In the legume Medicago truncatula, this response also appears to be influenced by RDN1, a member of the hydroxyproline-O-arabinosyltransferase (HPAT) family which can modify specific CLE peptides. However, it is not known if this signalling pathway plays a central role in root development across species, and in particular root responses to N. In this study, we systematically examined the role of the CLV signalling pathway genes in root development of the legume pea (Pisum sativum) and non-legume tomato (Solanum lycopersicum) using a mutant-based approach. This included a detailed examination of root development in response to N in tomato mutants disrupted in CLV1- or CLV2-like genes or HPAT family member FIN. We found no evidence for a role of these genes in pea seedling root development. Furthermore, the CLV1-like FAB gene did not influence tomato root development, including the root response to N supply. In contrast, both CLV2 and the HPAT gene FIN appear to positively influence root size in tomato but do not mediate root responses to N. These results suggest the function of these genes may vary somewhat in different species, including the N regulation of root architecture.

A comprehensive analysis of the role of brassinosteroids in nodulation, including their interactions with auxin and ethylene revealed that brassinosteroids inhibit infection, promote nodule initiation but do not influence nodule organogenesis or function. Nodulation, the symbiosis between legumes and rhizobial bacteria, is regulated by a suite of hormones including brassinosteroids. Previous studies have found that brassinosteroids promote nodule number by inhibiting ethylene biosynthesis. In this study, we examined the influence of brassinosteroids on the various stages of infection and nodule development. We utilise pea mutants, including brassinosteroid mutants lk, lka and lkb, the ethylene insensitive ein2 mutant and the lk ein2 double mutant, along with transgenic lines expressing the DR5::GUS auxin activity marker to investigate how brassinosteroids interact with ethylene and auxin during nodulation. We show that brassinosteroids inhibit the early stages of nodulation, including auxin accumulation, root hair deformation and infection thread formation, and demonstrate that infection thread formation is regulated by brassinosteroids in an ethylene independent manner. In contrast, brassinosteroids appear to act as promoters of nodule initiation through both an ethylene dependent and independent pathway. Although brassinosteroids positively influence the ultimate number of nodules formed, we found that brassinosteroid-deficiency did not influence nodule structure including the vascular pattern of auxin activity or nitrogen-fixation capacity. These findings suggest that brassinosteroids are negative regulators of infection but positive regulators of nodule initiation. Furthermore, brassinosteroids do not appear to be essential for nodule organogenesis or function. Given the influence of brassinosteroids on discreet stages of nodulation but not nodule function, manipulation of brassinosteroids may be an interesting avenue for future research on the optimisation of nodulation.

Background The presence of a polar auxin transport stream has long been correlated with the differentiation and patterning of vascular cells across vascular plants. As our understanding of auxin transport and vascular development has grown, so too has evidence for the correlation between these processes. However, a clear understanding of the cellular and molecular mechanisms driving this correlation has not been elucidated. Scope This article examines the hypothesis that canalization via polar auxin transport regulates vascular reconnection and patterning in the stem after wounding or grafting. We examine the evidence for the causal nature of the relationship and the suggested role that other hormones may play. Data are presented indicating that in grafted plants the degree of auxin transport may not always correlate with vascular reconnection. Furthermore, data on grafting success using plants with a range of hormone-related mutations indicate that these hormones may not be critical for vascular reconnection. Conclusions In the past, excellent work examining elements of auxin synthesis, transport and response in relation to vascular development has been carried out. However, new experimental approaches are required to test more directly the hypothesis that auxin transport regulates stem vascular reconnection after wounding or grafting. This could include studies on the timing of the re-establishment of auxin transport and vascular reconnection after grafting and the influence of auxin transport mutants and inhibitors on these processes using live imaging.

This paper presents a review of integrated interpretation of geophysical surveys with geological data for interpretation and exploration targeting for detrital iron deposits at the Koodaideri Project, Western Australia. Significant previous exploration has been conducted in the area and this has identified a number of detrital iron deposits. The aim of this project has been to integrate all available geoscientific data in order to assess remaining prospectivity of the area and provide a framework for future exploration and evaluation projects. Previous exploration at Koodaideri has used a variety of techniques including drilling, downhole geophysical logs, sparse refraction seismic, airborne and ground gravity, airborne magnetics and time-domain airborne electromagnetics. Spatial coverage of the individual exploration datasets is irregular, and the first stage of this project has focussed on an area of approximately 42 km × 12 km within which there is reasonably good coverage of all data types. The relatively high data density has allowed the relationships between the various data types to be assessed and effective exploration parameters to be defined. The larger detrital iron deposits at Koodaideri occur within palaeochannels or depressions within the basement, which is mainly comprised of units of the Wittenoom Formation. The detrital iron deposits are considered to have been sourced from erosion of bedded iron deposits of the Brockman Iron Formation which outcrops on the high ground both upstream and immediately to the southwest of the area of interest. The known deposits generally occur beneath cover of variable thickness of up to 50 m. The detrital deposits themselves may have thicknesses in excess of 100 m in major palaeochannels and sinkholes. The detrital deposits have a higher density than other cover units due to their high iron content (>50% Fe). However, gravity alone is not an effective exploration technique because the gravity signature is complicated by significant variability in the depth to higher density Wittenoom Formation bedrock. A more recent development is use of a modified seismic refraction method (Sparse Refraction Seismic) to constrain the basement topography, and then to model and remove the basement response from the observed gravity data to identify areas of anomalous excess mass. This approach has allowed cost-effective semi-regional exploration and has been successful in identifying all known major detrital iron deposits. This study extended the excess mass approach by constructing revised basement models from the sparse refraction seismic and drilling and from interpretation of the SkyTEM airborne electromagnetic and drilling. The results show that the basement interface can be interpreted from either the seismic or airborne electromagnetic datasets, although the airborne electromagnetic interpretation is complicated by highly saline groundwater in the northeastern quadrant of the area and by conductive shale units within the Wittenoom Formation bedrock. Almost all of the known detrital and channel iron deposits are spatially associated with an overlying pisolite unit, which can be identified from the magnetic data via its characteristic magnetic texture. These studies have shown that the derived excess mass is spatially associated with the known detrital and channel iron mineralisation. Significantly, almost all of the known deposits were also successfully identified from the simple geological model, in the absence of drill hole constraints. A number of untested areas of possible mineralisation have been identified, as well as potential extensions or alternate trends to known mineralisation. The modelling scenarios tested confirmed that the minimum elements for exploration targeting at Koodaideri are a geological model incorporating basement topography, interpreted magnetic domains and geologically constrained inversion of the gravity data.

Plant hormones play key roles in nodulation and arbuscular mycorrhizal (AM) associations. These two agriculturally and ecologically important symbioses enable plants to gain access to nutrients, in particular, nitrogen in the case of nodulation and phosphorous in the case of AM. Work over the past few decades has revealed how symbioses with nitrogen-fixing rhizobia, restricted almost exclusively to legumes, evolved in part from ancient AM symbioses formed by more than 80% of land plants. Although overlapping, these symbiotic programs also have important differences, including the de novo development of a new organ found only in nodulation. One emerging area of research is the role of two plant hormone groups, the gibberellins (GAs) and brassinosteroids (BRs), in the development and maintenance of these symbioses. In this review, we compare and contrast the roles of these hormones in the two symbioses, including potential interactions with other hormones. This not only focuses on legumes, most of which can host both symbionts, but also examines the role of these in AM development in non-legumes. GA acts by suppressing DELLA, and this regulatory module acts to negatively influence both rhizobial and mycorrhizal infection but appears to promote nodule organogenesis. While an overall positive role for BRs in nodulation and AM has been suggested by studies using mutants disrupted in BR biosynthesis or response, application studies indicate that BR may play a more complex role in nodulation. Given the nature of these symbioses, with events regulated both spatially and temporally, future studies should examine in more detail how GAs and BRs may influence precise events during these symbioses, including interactions with other hormone groups.

Legume nodules are a unique plant organ that contain nitrogen-fixing rhizobial bacteria. For this interaction to be mutually beneficial, plant and bacterial metabolism must be precisely co-ordinated. Plant hormones are known to play essential roles during the establishment of legume-rhizobial symbioses but their role in subsequent nodule metabolism has not been explored in any depth. The plant hormones brassinosteroids, ethylene and gibberellins influence legume infection, nodule number and in some cases nodule function. In this paper, the influence of these hormones on nodule metabolism was examined in a series of well characterised pea mutants with altered hormone biosynthesis or response. A targeted set of metabolites involved in nutrient exchange and nitrogen fixation was examined in nodule tissue of mutant and wild type plants. Gibberellin-deficiency had a major negative impact on the level of several major dicarboxylates supplied to rhizobia by the plant and also led to a significant deficit in the amino acids involved in glutamine-aspartate transamination, consistent with the limited bacteroid development and low fixation rate of gibberellin-deficient na mutant nodules. In contrast, no major effects of brassinosteroid-deficiency or ethylene-insensitivity on the key metabolites in these pathways were found. Therefore, although all three hormones influence infection and nodule number, only gibberellin is important for the establishment of a functional nodule metabolome.

SUMMARY VPem3D performs 3D inversion on time-integrated (resistive limit) data. Conversion to resistive limits delivers a massive increase in speed since the TEM inverse problem reduces to a quasi-magnetic problem. The time evolution of the decay is lost during the conversion, but the information can be largely recovered by constructing a starting model from CDIs or 1D inversions. We have carried out preliminary inversion of VTEM dBz/dt data from the Forrestania EM test range. The inversion places a weak conductor at a depth and location consistent with the known target. Run time is a few minutes, a fraction of that required by a full 3D EM inversion.

Plant hormones play key roles in defence against pathogen attack. Recent work has begun to extend this role to encompass not just the traditional disease/stress hormones, such as ethylene, but also growth-promoting hormones. Strigolactones (SLs) are the most recently defined group of plant hormones with important roles in plant–microbe interactions, as well as aspects of plant growth and development, although the knowledge of their role in plant– pathogen interactions is extremely limited. The oomycete Pythium irregulare is a poorly controlled pathogen of many crops. Previous work has indicated an important role for ethylene in defence against this oomycete. We examined the role of ethylene and SLs in response to this pathogen in pea ( Pisum sativum L.) at the molecular and whole-plant levels using a set of well-characterized hormone mutants, including an ethylene-insensitive ein2 mutant and SL-deficient and insensitive mutants.We identified a key role for ethylene signalling in specific cell types that reduces pathogen invasion, extending the work carried out in other species. However, we found no evidence that SL biosynthesis or response influences the interaction of pea with P. irregulare or that synthetic SL influences the growth or hyphal branching of the oomycete in vitro . Future work should seek to extend our understanding of the role of SLs in other plant interactions, including with other fungal, bacterial and viral pathogens, nematodes and insect pests.

Plant responses to light involve a complex network of interactions among multiple plant hormones. In a screen for mutants showing altered photomorphogenesis under red light, we identified a mutant with dramatically enhanced leaf expansion and delayed petal senescence. We show that this mutant exhibits reduced sensitivity to ethylene and carries a nonsense mutation in the single pea (Pisum sativum) ortholog of the ethylene signaling gene ETHYLENE INSENSITIVE2 (EIN2). Consistent with this observation, the ein2 mutation rescues the previously described effects of ethylene overproduction in mature phytochrome-deficient plants. In seedlings, ein2 confers a marked increase in leaf expansion under monochromatic red, far-red, or blue light, and interaction with phytochromeA, phytochromeB, and long1 mutants confirms that ein2 enhances both phytochrome- and cryptochrome-dependent responses in a LONG1-dependent manner. In contrast, minimal effects of ein2 on seedling development in darkness or high-irradiance white light show that ethylene is not limiting for development under these conditions. These results indicate that ethylene signaling constrains leaf expansion during deetiolation in pea and provide further evidence that down-regulation of ethylene production may be an important component mechanism in the broader control of photomorphogenic development by phytochrome and cryptochrome.

Gibberellin plays a dual role in legumes during uptake and accommodation of nitrogen-fixing bacteria; inhibiting infection at the epidermis but promoting nodule organogenesis and ultimate function., Leguminous plant roots can form a symbiosis with soil-dwelling nitrogen-fixing rhizobia, leading to the formation of a new root organ, the nodule. Successful nodulation requires co-ordination of spatially separated events in the root, including infection in the root epidermis and nodule organogenesis deep in the root cortex. We show that the hormone gibberellin plays distinct roles in these epidermal and cortical programmes. We employed a unique set of genetic material in pea that includes severely gibberellin-deficient lines and della-deficient lines that enabled us to characterize all stages of infection and nodule development. We confirmed that gibberellin suppresses infection thread formation and show that it also promotes nodule organogenesis into nitrogen-fixing organs. In both cases, this is achieved through the action of DELLA proteins. This study therefore provides a mechanism to explain how both low and high gibberellin signalling can result in reduced nodule number and reveals a clear role for gibberellin in the maturation of nodules into nitrogen-fixing organs. We also demonstrate that gibberellin acts independently of ethylene in promoting nodule development.

Strigolactones (SLs) influence the ability of legumes to associate with nitrogen-fixing bacteria. In this study we determine the precise stage at which SLs influence nodulation. We show that SLs promote infection thread formation, as a null SL-deficient pea (Pisum sativum) mutant forms significantly less infection threads than wild type plants and this reduction can be overcome by the application of the synthetic SL GR24. We found no evidence that SLs influence physical events in the plant before or after infection thread formation, since SL-deficient plants displayed a similar ability to induce root hair curling in response to rhizobia or lipochito-oligosaccharides (LCOs) and SL-deficient nodules appear to fix nitrogen at a similar rate to wild type plants. In contrast, a SL receptor mutant displayed no decrease in infection thread formation or nodule number, suggesting SL-deficiency may influence the bacterial partner. We found this influence of SL-deficiency was not due to altered flavonoid exudation or ability of root exudates to stimulate bacterial growth. The influence of SL-deficiency on infection thread formation was accompanied by reduced expression of some early nodulation (ENOD) genes. Importantly, SL synthesis is down-regulated by mutations in genes of the Nod LCO signalling pathway and this requires the downstream transcription factor NSP2 but not NIN. This, together with the fact that the expression of certain SL biosynthesis genes can be elevated in response to rhizobia/Nod factors suggests that Nod LCOs may induce SL biosynthesis. SLs appear to influence nodulation independently of ethylene action, as SL-deficient and ethylene insensitive double mutant plants display essentially additive phenotypes and we found no evidence that SLs influence ethylene synthesis or vice versa.

Background and Aims: The number of nodules formed on a legume root system is under the strict genetic control of the autoregulation of nodulation (AON) pathway. Plant hormones are thought to play a role in AON; however, the involvement of two hormones recently described as having a largely positive role in nodulation, strigolactones and brassinosteroids, has not been examined in the AON process. Methods: A genetic approach was used to examine if strigolactones or brassinosteroids interact with the AON system in pea ( Pisum sativum ). Double mutants between shoot-acting ( Psclv2, Psnark ) and root-acting ( Psrdn1 ) mutants of the AON pathway and strigolactone-deficient ( Psccd8 ) or brassinosteroid-deficient ( lk ) mutants were generated and assessed for various aspects of nodulation. Strigolactone production by AON mutant roots was also investigated. Key Results: Supernodulation of the roots was observed in both brassinosteroid- and strigolactone-deficient AON double-mutant plants. This is despite the fact that the shoots of these plants displayed classic strigolactone-deficient (increased shoot branching) or brassinosteroid-deficient (extreme dwarf) phenotypes. No consistent effect of disruption of the AON pathway on strigolactone production was found, but root-acting Psrdn1 mutants did produce significantly more strigolactones. Conclusions: No evidence was found that strigolactones or brassinosteroids act downstream of the AON genes examined. While in pea the AON mutants are epistatic to brassinosteroid and strigolactone synthesis genes, we argue that these hormones are likely to act independently of the AON system, having a role in the promotion of nodule formation.

During 2011 Groundprobe Geophysics flew a SkyTEM airborne electromagnetic (AEM) survey in the vicinity of Lake Thetis near Cervantes in Western Australia. The survey was commissioned by the Western Australian Department of Water as part of the Mid West Groundwater Dependent Ecosystem Vulnerability Project. Groundprobe Geophysics processed and then initially inverted the dataset using the iTEM fast approximate inversion. Subsequently the data were inverted using a reversible jump Markov chain Monte Carlo (rj-McMC) 1D inversion algorithm recently developed at Geoscience Australia. Both the high- and super-low-moment data were inverted simultaneously taking into account the tilts of the transmitter-receiver frame. In the inversion of each dual-moment AEM sounding an ensemble of 300,000 models were generated in a Markov Chain, about 290,000 of which fit the data within the estimated noise envelope. The reversible jump aspect of the algorithm means that the number of layers in the 1D models varies, and the algorithm tends to favour models with the fewest number of layers that allow the data to be fitted, in essence providing a data-driven Occam's Razor. The algorithm is considerably more computationally expensive than deterministic inversions. However its advantage is that a great deal of information can be extracted from the ensemble. For example, the most likely, mean, mode and median models were all extracted and made into conductivity depth slice maps and sections. We extract the 10th and 90th percentile models and use the spread between them as a measure of model uncertainty, which we convey on maps by making uncertain areas more transparent. Another output of the algorithm is a change-point histogram which provides information on the most probable depths of the layer interfaces. By extracting the peaks from this histogram we begin to be able to automatically interpret layer boundaries to be plotted onto conductivity sections.

SUMMARY In 2011 a review of an historical TEMPEST airborne electromagnetic survey in the Murchison Region of Western Australia identified a number of discrete bedrock conductor anomalies potentially associated with base metal mineralisation. One of the anomalies identified was in close proximity to a known gossan at Hollandaire, within rocks of the Archaean Mt Eelya Complex. The Hollandaire gossan had been previously investigated during the mid-late 1970’s using a variety of geological, geochemical and geophysical methods, including ground magnetics, induced polarisation, magnetic induced polarisation and time-domain electromagnetics. A single line of time-domain in-loop transient electromagnetic data was collected at Hollandaire during 2011, in order to follow up the TEMPEST bedrock conductor. A strong time-domain EM anomaly was identified, with a very high time-constant of 107 ms. Plate modelling of the in-loop data resulted in a target at depth-to-top 100 m, dipping at 45 degrees to the westnorthwest, and with conductance 5000 S. The nine initial holes drilled to test the electromagnetic target all intersected sulphide mineralisation. The inferred resource now totals 2.8 million tonnes at 1.6% Cu, 0.4 g/t Au and 5 g/t Ag, with the supergene zone averaging 4.7% Cu. Subsequent downhole electromagnetic (DHEM) surveys have identified an off-hole electromagnetic conductor to the south of the known mineralisation, which has not yet been tested by drilling.

A TEMPEST airborne electromagnetic survey was flown in the Albany Hinterland with the objective of determining likely palaeochannel locations for future groundwater exploration. The basement in the survey area is the Proterozoic Nornalup Complex, which is overlain by Tertiary-Eocene sediments, including the Werillup Formation and Pallinup Siltstone. These units are overlain by Quaternary sediments of thickness 10 – 70 m. The maximum thickness of cover materials overlying basement is ~100 m. The main aquifers in the area are Werillup Formation sands within palaeochannels incised into the basement. The conductivity derived from the TEMPEST data shows a layer of moderate electrical conductivity (50 – 150+ mS/m), which correlates well with clayey units within the Werillup Formation, and possibly also the weathered upper part of the Proterozoic bedrock. Bedrock conductivities are typically low (average ~1.2 mS/m). The strong electrical contrast between the Werillup Formation and the bedrock allowed depth to Proterozoic basement to be interpreted from the TEMPEST data. This was done by conventional unconstrained layered-earth inversion followed by manual interpretation of the depth to bedrock on each survey line. The interpreted bedrock depths were used to construct a triangulated surface representing base of cover. Geologically-constrained inversion of the TEMPEST data was then undertaken to refine the preliminary depth to basement model. Geological constraints on the model were provided by drillhole basement pierce points and outcrop. A large number of drillholes which did not reach bedrock were also used. The inversion was constrained to place the final bedrock surface below the ends of these drillholes. The geologically-constrained inversion and subsequent synthesised interpretation identified a number of bedrock lows which have been confirmed by drilling to correspond to palaeochannels, and has defined four main groundwater resource areas. The results of the interpretation have formed the framework for the Albany Hinterland Prospective Groundwater map (Ryan et al., 2016).

Aim Demographic linkage between subpopulations plays a critical role in population processes. Metapopulation dynamics, however, remains one of the most poorly understood aspects of population biology. This is especially true for small, pelagic seabirds because their discrete subpopulations are located on offshore islands, separated by vast areas of open ocean, making monitoring logistically challenging. Seabird populations often contain large numbers of immature pre-breeders that may be important for subpopulation connectivity and demography, but are poorly studied. Here we provide evidence for intercolony movement of pre-breeding Leach's storm-petrels Oceanodroma leucorhoa among three colonies spanning the North Atlantic Ocean. We discuss their influence on metapopulation dynamics and the extinction risk of a subpopulation under threat from extreme predation. Location North Atlantic Ocean Islands (Scotland, Canada & Iceland). Methods We use a novel application of Bayesian stable isotope mixing models to infer recent movement of pre-breeding birds between three major breeding populations in the North Atlantic. Carbon and nitrogen stable isotope values from breeding birds (central place foragers) sampled at each colony were used as model sources and pre-breeding birds as model mixtures. Results Of 134 pre-breeding Leach's storm-petrels sampled at three colonies across the North Atlantic, five had isotope mixing model estimates dissimilar (

The role of abscisic acid (ABA) in triggering ethylene biosynthesis and ripening of mango fruit was investigated by applying ABA [S-(+)-cis,trans-abscisic acid] and an inhibitor of its biosynthesis [nordihydroguaiaretic acid (NDGA)]. Application of 1 mM ABA accelerated ethylene biosynthesis through promoting the activities of ethylene biosynthesis enzymes (1-aminocyclopropane-1-carboxylic acid synthase, ACS; 1-aminocyclopropane-1-carboxylic acid oxidase, ACO) and accumulation of 1-aminocyclopropane-1-carboxylic acid (ACC), enhanced fruit softening and activity of endo-polygalacturonase and reduced pectin esterase activity in the pulp. The activities of ethylene biosynthesis and softening enzymes were significantly delayed and/or suppressed in the pulp of NDGA-treated fruit. The ABA-treated fruit had higher total sugars and sucrose as well as degradation of total organic acids, and citric and fumaric acids compared with NDGA treatment. These results suggest that ABA is involved in regulating mango fruit ripening and its effects are, at least in part, mediated by changes in ethylene production.

New roles for the recently identified group of plant hormones, the strigolactones, are currently under active investigation. One of their key roles is to regulate plant symbioses. These compounds act as a rhizosphere signal in arbuscular mycorrhizal symbioses and as a positive regulator of nodulation in legumes. The phosphorous and nitrogen status of the soil has emerged as a powerful regulator of strigolactone production. However, until now, the potential role of strigolactones in regulating mycorrhizal development and nodulation in response to nutrient deficiency has not been proven. In this paper, the role of strigolactone synthesis and response in regulating these symbioses is examined in pea (Pisum sativum L.). Pea is well suited to this study, since there is a range of well-characterized strigolactone biosynthesis and response mutants that is unique amongst legumes. Evidence is provided for a novel endogenous role for strigolactone response within the root during mycorrhizal development, in addition to the action of strigolactones on the fungal partner. The strigolactone response pathway that regulates mycorrhizal development also appears to differ somewhat from the response pathway that regulates nodulation. Finally, studies with strigolactone-deficient pea mutants indicate that, despite strong regulation of strigolactone production by both nitrogen and phosphate, strigolactones are not required to regulate these symbioses in response to nutrient deficiency.

In 2011, several Bowen Basin coal exploration projects in central Queensland were surveyed with the SkyTEM airborne electromagnetic system. The aim of these surveys was to trial the effectiveness of the method in for coal applications, with specific focus on mapping the key aspects of the weathering, overburden and hydrology that are most important for effective development of a coal project. The first survey, which was over an area near Moranbah with 150m of Tertiary overburden with extensive basalt flows, mapped crucial hydrological and geological features important to efficient further development of the project: These included a) a convoluted network of basalt-filled palaeochannels, some of which extend through and into the coal measures b) location, extent and thickness of major saline aquifers, c) depth to base of Tertiary. Subsequent surveys over different parts of the Bowen basin, showed that SkyTEM was a very effective tool for mapping the thickness of weathering, a parameter very important for drilling out coal resources. The results are surprising in that they not only provide a detailed map of depth of weathering (including volumes of lateritic sediments requiring excavation), but also map more subtle geological features such as synclines (previously only loosely inferred from surface mapping), major faults, previously unknown dykes, dip and strike of the main stratigraphic units, fresh water aquifers and even possibly also various coal seams (generally because they are saline aquifers). These surveys represent, at least to the authors? knowledge, the first example of modern helicopter-borne transient EM in the Australian coal fields. The results from this project and subsequent projects are surprising in that they have had unexpected applications above and beyond those which were originally forecast. Thus, with informed and thorough use, airborne EM promises to deliver valuable geological and geotechnical information to aid in the further development of Australia?s coal resources.

SUMMARY The SkyTEM helicopter transient electromagnetic system has been used to map the environs of a number of tailings dams in Australia. Residues from mining and industrial processes typically have high conductivity and can be effectively mapped using airborne electromagnetic methods. Airborne surveys allow complete coverage of tailings sites otherwise inaccessible to surface geophysics. The SkyTEM system is capable of operating in a dual moment mode, in which measurements with low transmitter current, fast switch off and early-time sampling are interleaved with those performed using a high transmitter moment and measurements to late delay times. This provides high near-surface resolution and the capability to penetrate through thick accumulations of highly-conductive tailings. Surveys around tailings sites are characterised by significant surface infrastructure, which presents hazards to airborne operations and results in numerous cultural electromagnetic anomalies unrelated to the subsurface. These obstacles can be overcome with appropriate survey planning and careful editing of the airborne data prior to interpretation. A brief field example from a coal fly-ash dam in Australia illustrates the ability of the SkyTEM system to provide detailed hydrogeophysical information. Useful data were obtained even in close proximity to metallic infrastructure and high-voltage power lines. The SkyTEM survey was able to identify several zones of anomalous conductivity at points downstream of the embankment, which are a priority for future ground follow-up.

Protein farnesylation is a post-translational modification involving the addition of a 15-carbon farnesyl isoprenoid to the carboxy terminus of select proteins(1-3). Although the roles of this lipid modification are clear in both fungal and animal signalling, many of the mechanistic functions of farnesylation in plant signalling are still unknown. Here, we show that CYP85A2, the cytochrome P450 enzyme that performs the last step in brassinosteroid biosynthesis (conversion of castasterone to brassinolide)(4), must be farnesylated to function in Arabidopsis. Loss of either CYP85A2 or CYP85A2 farnesylation results in reduced brassinolide accumulation and increased plant responsiveness to the hormone abscisic acid (ABA) and overall drought tolerance, explaining previous observations(5). This result not only directly links farnesylation to brassinosteroid biosynthesis but also suggests new strategies to maintain crop yield under challenging climatic conditions.

Highlight An ethylene-insensitive mutant of pea with enhanced nodulation and arbuscular mycorrhizal development showed that gibberellin and brassinosteroid deficiency affect nodule number via ethylene levels., The regulation of arbuscular mycorrhizal development and nodulation involves complex interactions between the plant and its microbial symbionts. In this study, we use the recently identified ethylene-insensitive ein2 mutant in pea (Pisum sativum L.) to explore the role of ethylene in the development of these symbioses. We show that ethylene acts as a strong negative regulator of nodulation, confirming reports in other legumes. Minor changes in gibberellin1 and indole-3-acetic acid levels in ein2 roots appear insufficient to explain the differences in nodulation. Double mutants produced by crosses between ein2 and the severely gibberellin-deficient na and brassinosteroid-deficient lk mutants showed increased nodule numbers and reduced nodule spacing compared with the na and lk single mutants, but nodule numbers and spacing were typical of ein2 plants, suggesting that the reduced number of nodules in na and lk plants is largely due to the elevated ethylene levels previously reported in these mutants. We show that ethylene can also negatively regulate mycorrhizae development when ethylene levels are elevated above basal levels, consistent with a role for ethylene in reducing symbiotic development under stressful conditions. In contrast to the hormone interactions in nodulation, ein2 does not override the effect of lk or na on the development of arbuscular mycorrhizae, suggesting that brassinosteroids and gibberellins influence this process largely independently of ethylene.

Strigolactones are an ancient group of plant signalling molecules. They play a critical role in the rhizosphere where they facilitate the formation of symbioses with fungi, crucial for the acquisition of plant nutrients in over 80 % of land plant species. Strigolactones have also been exploited by parasitic weeds as a rhizosphere signal indicating the presence of a host species, resulting in devastating losses in some agricultural systems. Recently, they have also been shown to act endogenously as plant hormones controlling shoot branching and have been implicated in a wide range of other physiological processes, including root growth, root-hair elongation, adventitious rooting, secondary growth, photomorphogenesis, seed germination, nodulation, and protonemal development in mosses. Here, we discuss the evidence for the involvement of strigolactones as endogenous regulators of these processes and highlight some examples where the evidence is inconclusive. One major gap in our understanding is the identity of the endogenous strigolactone(s) that are biologically active. A discussion of the interactions between the different plant hormones and the possible role of strigolactones as integrators of the root-to-shoot balance, nutrient acquisition, and thus resource allocation illustrates some important future directions for this area of research.

The red-throated diver ( Gavia stellata ) is listed on Annex I of the European Union Birds Directive and requires protection within Special Protection Areas (SPAs), among other conservation measures. The Outer Thames Estuary, east England, was known to support almost half of the Great Britain wintering population of red-throated divers but delineating an SPA boundary there was not straightforward as existing boundary-setting methods did not perform well. The number and distribution of red-throated divers in the Outer Thames Estuary was determined using visual aerial survey methods. Bird observations were smoothed using kernel density estimation (KDE) and were combined to create a mean modelled density surface. A threshold density was identified using maximum curvature and an SPA boundary was drawn around all cells on the density surface with a density greater than the threshold density. The SPA boundary contained 6301 red-throated divers in an area of 3937 km 2 , which was 77.5% of the estimated Outer Thames Estuary red-throated diver population in an area of only 38.9% of the study area. This boundary was adopted in 2010 when the Outer Thames Estuary SPA was classified. This method is suited to a species that is aggregated at medium to large scales and for which appropriate environmental covariates are lacking. It is relatively simple, which is advantageous when communicating methods to non-scientists, and provides an objective method for drawing an MPA boundary that is robust to challenge by stakeholders who may wish the MPA to be larger or smaller.

Marine Protected Areas (MPAs) are recognised as a key component of an ecosystem-based approach to managing the marine environment more effectively and sustainably. Marine top predators, such as seabirds, may be used to identify and prioritize sites for marine conservation. Here we highlight the important role that seabird scientists can play in identifying candidate sites for MPAs; areas identified using at-sea surveys, seabird tracking, and species-habitat modelling. Prioritization of species and sites needs knowledge of ecological and habitat dynamics, threats and important areas at key stages of annual and life-cycle. The results need to be interpreted within the context of relevant policy mechanisms and agreements. The size and shape of candidate MPAs should be: (a) realistic for the key species and systems involved; (b) easy to monitor and enforce; and (c) where feasible involve reasonably long-term data sets. Designation of MPAs by relevant authorities and organisations will require effective advocacy (at local, national and international levels) and must be based on robust and defensible science. Site boundaries should also be sufficient flexibility to be modified, if necessary, in the light of future experience and data collection. The effectiveness of MPAs at the scale required for seabird conservation will need to build on existing experience and develop innovative, as well as traditional, marine spatial planning, monitoring and management techniques. To achieve this within the target timeframes outlined in a number of policy mechanisms will require the rapid development of new approaches, resources and partnerships.

In contrast to climacteric fruits, where ethylene is known to be pivotal, the regulation of ripening in non-climacteric fruits is not well understood. In the non-climacteric strawberry (Fragaria anannassa), auxin and abscisic acid (ABA) are thought to be important, but the roles of other hormones suggested to be involved in fruit development and ripening are not clear. Here changes in the levels of indole-3-acetic acid (IAA), ABA, GA1, and castasterone from anthesis to fully ripened fruit are reported. The levels of IAA and GA1 rise early in fruit development before dropping to low levels prior to colour accumulation. Castasterone levels are highest at anthesis and drop to very low levels well before ripening commences, suggesting that brassinosteroids do not play an important role in ripening in strawberry. ABA levels are low at anthesis and gradually rise through development and ripening. The synthetic auxin, 1-naphthaleneacetic acid (NAA), can delay ripening, but the application of GA3, the gibberellin biosythesis inhibitor paclobutrazol, and ABA had no significant effect. IAA and ABA levels are higher in the developing achenes than in the receptacle tissue and may be important for receptacle enlargement and ripening, and seed maturation, respectively. Contrary to a recent report, the biologically active GA4 was not detected. The pattern of changes in the levels of the hormones are different from those reported in another well studied non-climateric fruit, grape, suggesting that a single consistent pattern of hormone changes does not occur in this group of fruit during ripening.

Dramatic local population decline brought about by anthropogenic-driven change is an increasingly common threat to biodiversity. Seabird life history traits make them particularly vulnerable to such change; therefore, understanding population connectivity and dispersal dynamics is vital for successful management. Our study used a 357-base pair mitochondrial control region locus sequenced for 103 individuals and 18 nuclear microsatellite loci genotyped for 245 individuals to investigate population structure in the Atlantic and Pacific populations of the pelagic seabird, Leach's storm-petrel Oceanodroma leucorhoa leucorhoa. This species is under intense predation pressure at one regionally important colony on St Kilda, Scotland, where a disparity between population decline and predation rates hints at immigration from other large colonies. AMOVA, F(ST), Φ(ST) and Bayesian cluster analyses revealed no genetic structure among Atlantic colonies (Global Φ(ST) = -0.02 P > 0.05, Global F(ST) = 0.003, P > 0.05, STRUCTURE K = 1), consistent with either contemporary gene flow or strong historical association within the ocean basin. The Pacific and Atlantic populations are genetically distinct (Global Φ(ST) = 0.32 P < 0.0001, Global F(ST) = 0.04, P < 0.0001, STRUCTURE K = 2), but evidence for interocean exchange was found with individual exclusion/assignment and population coalescent analyses. These findings highlight the importance of conserving multiple colonies at a number of different sites and suggest that management of this seabird may be best viewed at an oceanic scale. Moreover, our study provides an illustration of how long-distance movement may ameliorate the potentially deleterious impacts of localized environmental change, although direct measures of dispersal are still required to better understand this process.

The distribution, movements and abundance of highly mobile marine species such as bottlenose dolphins Tursiops truncatus are best studied at large spatial scales, but previous research effort has generally been focused on relatively small areas, occupied by populations with high site fidelity. We aimed to characterize the distribution, movements and abundance of bottlenose dolphins around the coasts of Scotland, exploring how data from multiple sources could be integrated to build a broader-scale picture of their ecology. We reviewed existing historical data, integrated data from ongoing studies and developed new collaborative studies to describe distribution patterns. We adopted a Bayesian multi-site mark-recapture model to estimate abundance of bottlenose dolphins throughout Scottish coastal waters and quantified movements of individuals between study areas. The majority of sightings of bottlenose dolphins around the Scottish coastline are concentrated on the east and west coasts, but records are rare before the 1990s. Dedicated photo-identification studies in 2006 and 2007 were used to estimate the size of two resident populations: one on the east coast from the Moray Firth to Fife, population estimate 195 [95% highest posterior density intervals (HPDI): 162–253] and the second in the Hebrides, population estimate 45 (95% HPDI: 33–66). Interaction parameters demonstrated that the dolphins off the east coast of Scotland are highly mobile, whereas those off the west coast form two discrete communities. We provide the first comprehensive assessment of the abundance of bottlenose dolphins in the inshore waters of Scotland. The combination of dedicated photo-identification studies and opportunistic sightings suggest that a relatively small number of bottlenose dolphins (200–300 individuals) occur regularly in Scottish coastal waters. On both east and west coasts, re-sightings of identifiable individuals indicate that the animals have been using these coastal areas since studies began.

Rapid ripening of mango fruit limits its distribution to distant markets. To better understand and perhaps manipulate this process, we investigated the role of plant hormones in modulating climacteric ripening of ‘Kensington Pride’ mango fruits. Changes in endogenous levels of brassinosteroids (BRs), abscisic acid (ABA), indole-3-acetic acid (IAA), and ethylene and the respiration rate, pulp firmness, and skin color were determined at 2-day intervals during an 8-day ripening period at ambient temperature (21 ± 1°C). We also investigated the effects of exogenously applied epibrassinolide (Epi-BL), (+)-cis, trans-abscisic acid (ABA), and an inhibitor of ABA biosynthesis, nordihydroguaiaretic acid (NDGA), on fruit-ripening parameters such as respiration, ethylene production, fruit softening, and color. Climacteric ethylene production and the respiration peak occurred on the fourth day of ripening. Castasterone and brassinolide were present in only trace amounts in fruit pulp throughout the ripening period. However, the exogenous application of Epi-BL (45 and 60 ng g−1 FW) advanced the onset of the climacteric peaks of ethylene production and respiration rate by 2 and 1 day, respectively, and accelerated fruit color development and softening during the fruit-ripening period. The endogenous level of ABA rose during the climacteric rise stage on the second day of ripening and peaked on the fourth day of ripening. Exogenous ABA promoted fruit color development and softening during ripening compared with the control and the trend was reversed in NDGA-treated fruit. The endogenous IAA level in the fruit pulp was higher during the preclimacteric minimum stage and declined during the climacteric and postclimacteric stages. We speculate that higher levels of endogenous IAA in fruit pulp during the preclimacteric stage and the accumulation of ABA prior to the climacteric stage might switch on ethylene production that triggers fruit ripening. Whilst exogenous Epi-BL promoted fruit ripening, endogenous measurements suggest that changes in BRs levels are unlikely to modulate mango fruit ripening.

To understand the regulatory mechanisms involved in tissue development by light, the kinetics of regulation of Casparian strip (CS) development in garden pea stems was studied. We found that short-term irradiation with white light delayed the development of the CS and used this delay to assess the quantitative effect of light on CS development. We examined the effect of the duration and fluence rates of white light treatment on CS development and observed a significant relationship between fluence and the delay in CS development indicating that the Bunsen-Roscoe law of reciprocity holds for this response. The effect of white light irradiation was not inhibited in the presence of a photosynthetic inhibitor, DCMU, or a carotenoid biosynthesis inhibitor, Norflurazon, indicating that the delay in CS development by light is a photomorphogenetic response rather than a subsidiary effect mediated by photosynthetic activity. An action spectrum for the response displayed a major peak in the blue-light region, suggesting a dominant role for blue-light receptors. A minor peak in the red-light region also suggested the possible involvement of phytochromes. Although phytochromes are known to contribute to blue-light responses, phytochrome-deficient mutants showed a normal delay of CS development in response to blue light, indicating that the response is not mediated by phytochrome and suggesting a role for one or more specific blue-light receptors.

Models describing plant hormone interactions are often complex and web-like. Here we assess several suggested interactions within one experimental system, elongating pea internodes. Results from this system indicate that at least some suggested interactions between auxin, gibberellins (GAs), brassinosteroids (BRs), abscisic acid (ABA) and ethylene do not occur in this system or occur in the reverse direction to that suggested. Furthermore, some of the interactions are relatively weak and may be of little physiological relevance. This is especially true if plant hormones are assumed to show a log-linear response curve as many empirical results suggest. Although there is strong evidence to support some interactions between hormones (e.g. auxin stimulating ethylene and bioactive GA levels), at least some of the web-like complexities do not appear to be justified or are overstated. Simpler and more targeted models may be developed by dissecting out key interactions with major physiological effects.

The tryptamine pathway is one of five proposed pathways for the biosynthesis of indole-3-acetic acid (IAA), the primary auxin in plants. The enzymes AtYUC1 (Arabidopsis thaliana), FZY (Solanum lycopersicum), and ZmYUC (Zea mays) are reported to catalyze the conversion of tryptamine to N-hydroxytryptamine, putatively a rate-limiting step of the tryptamine pathway for IAA biosynthesis. This conclusion was based on in vitro assays followed by mass spectrometry or HPLC analyses. However, there are major inconsistencies between the mass spectra reported for the reaction products. Here, we present mass spectral data for authentic N-hydroxytryptamine, 5-hydroxytryptamine (serotonin), and tryptamine to demonstrate that at least some of the published mass spectral data for the YUC in vitro product are not consistent with N-hydroxytryptamine. We also show that tryptamine is not metabolized to IAA in pea (Pisum sativum) seeds, even though a PsYUC-like gene is strongly expressed in these organs. Combining these findings, we propose that at present there is insufficient evidence to consider N-hydroxytryptamine an intermediate for IAA biosynthesis.

Capsule Leach’s Storm‐petrels Oceanodroma leucorhoa may be depredated by endemic St Kilda Field Mice Apodemus sylvaticus hirtensis.

Although most Manx shearwaters (Puffinus puffinus) in the UK are protected within Special Protection Areas (SPAs) at their breeding colonies, such site-based protection does not currently extend into the marine environment. Manx shearwaters form rafts (dense flocks of birds) on the sea adjacent to their breeding colony from late afternoon onwards, before coming ashore after nightfall. The ecological and protection requirements of Manx shearwaters in the UK would be more completely addressed if existing SPA boundaries were extended into adjacent marine areas to include those used for rafting behaviour. However the spatial extent of rafts has never been assessed accurately. Because rafting behaviour continues after nightfall, radio-telemetry was used to investigate rafting distributions of Manx shearwaters around the three largest UK colonies: Skomer (south-west Wales), Bardsey (north-west Wales) and Rum (north-west Scotland). Totals of 30, 28 and 30 birds were radio-tagged, with 174, 264 and 385 rafting locations estimated for Skomer, Rum and Bardsey, respectively. Kernel contour analysis was used to describe the ‘rafting range’ around each colony. The maximum extent of the 95% kernel contours was used to determine the area which would encompass most rafting birds. The maximum extents of rafting ranges were 4, 6 and 9 km, respectively for Skomer, Rum and Bardsey. We believe this is the first successful illustration of how radio-telemetry data can potentially be used to define protected areas for birds in the marine environment.

An ecosystem approach to the management of the marine environment has received considerable attention over recent years. However, there are few examples which demonstrate its practical implementation. Much of this relates to the history of existing marine monitoring and assessment programmes which (for many countries) are sectoral, making it difficult to integrate monitoring data and knowledge across programmes at the operational level. To address this, a scientific expert group, under the auspices of the International Council for the Exploration of the Sea (ICES), prepared a plan for how ICES could contribute to the development of an Integrated Ecosystem Assessment (IEA) for the North Sea by undertaking a pilot study utilising marine monitoring data. This paper presents the main findings arising from the expert group and in particular it sets out one possible integrated approach for assessing the relative significance of environmental forcing and fishing pressure on the ecological status of the North Sea, it then compares the findings with assessments made of other Large Marine Ecosystems (LMEs). We define the North Sea ecosystem on the basis of 114 state and pressure variables resolved as annual averages between 1983 and 2003 and at the spatial scale of ICES rectangles. The paper presents results of integrated time-series and spatial analysis which identifies and explains significant spatial and temporal gradients in the data. For example, a significant shift in the status of the North Sea ecosystem (based upon 114 state-pressure variables) is identified to have occurred around 1993. This corresponds to previously documented shifts in the environmental conditions (particularly sea surface temperature) and changes in the distribution of key species of plankton (Calanus sp.), both reported to have occurred in 1989. The difference in specific timing between reported regime shifts for the North Sea may be explained, in part, by time-lag dependencies in the trophic structure of the ecosystem with shifts in higher trophic levels occurring later than 1989. By examining the connection (or relatedness) between ecosystem components (e.g. environment, plankton, fish, fishery and seabirds) for the identified regime states (1983–1993; 1993–2003) we conclude that both the North Sea pelagic and benthic parts of the ecosystem were predominantly top-down (fishery) controlled between 1983 and 1993, whereas between 1993 and 2003 the pelagic stocks shifted to a state responding mainly to bottom-up (environment) influences. However, for the demersal fish stocks between 1993 and 2003 top-down (fishery) pressure dominated even though over this period significant reductions in fishing pressure occurred. The present analysis, therefore, provides further evidence in support of the need for precautionary management measures taken in relation to setting fishery quotas.

Parsons, M., Mitchell, I., Butler, A., Ratcliffe, N., Frederiksen, M., Foster, S., and Reid, J. B. 2008. Seabirds as indicators of the marine environment. – ICES Journal of Marine Science, 65: 1520–1526. We report on the development of seabird indicators that support the Scottish Biodiversity Strategy. The application of high-quality monitoring data on breeding abundance and productivity in Scotland was explored in three ways: as indicators of seabird status in its own right, as indicators of the “health” of the marine environment, and as indicators of the food supply of vertebrate predators. Data on breeding productivity of seabirds, which responds more immediately to environmental variation than adult abundance, provided a novel supplement to indicators based solely on abundance trends. Grouping of species according to ecological guilds provided indicators of change in particular aspects of the marine environment. The role of seabird indicators in relation to policy frameworks is discussed, with a look to further developments at the UK and regional scales.