The combined effect of salinity and heat reveals a specific physiological,biochemical and molecular response in tomato plants

Many studies have described the response mechanisms of plants to salinity and heat applied individually; however, under field conditions some abiotic stresses often occur simultaneously. Recent studies revealed that the response of plants to a combination of two different stresses is specific and cannot be deduced from the stresses applied individually. Here, we report on the response of tomato plants to a combination of heat and salt stress. Interestingly, and in contrast to the expected negative effect of the stress combination on plant growth, our results show that the combination of heat and salinity provides a significant level of protection to tomato plants from the effects of salinity. We observed a specific response of plants to the stress combination that included accumulation of glycine betaine and trehalose. The accumulation of these compounds under the stress combination was linked to the maintenance of a high K⁺ concentration and thus a lower Na⁺/K⁺ ratio, with a better performance of the cell water status and photosynthesis as compared with salinity alone. Our findings unravel new and unexpected aspects of the response of plants to stress combination and provide a proposed list of enzymatic targets for improving crop tolerance to the abiotic field environment.     

Lifetime prevalence and age-of-onset distributions of mental disorders in the World Health Organization's World Mental Health Survey Initiative

Data are presented on the lifetime prevalence, projected lifetime risk, and age-of-onset distributions of mental disorders in the World Health Organization (WHO)''s World Mental Health (WMH) Surveys. Face-to-face community surveys were conducted in seventeen countries in Africa, Asia, the Americas, Europe, and the Middle East. The combined numbers of respondents were 85,052. Lifetime prevalence, projected lifetime risk, and age of onset of DSM-IV disorders were assessed with the WHO Composite International Diagnostic Interview (CIDI), a fully-structured lay administered diagnostic interview. Survival analysis was used to estimate lifetime risk. Median and inter-quartile range (IQR) of age of onset is very early for some anxiety disorders (7-14, IQR: 8-11) and impulse control disorders (7-15, IQR: 11-12). The age-of-onset distribution is later for mood disorders (29-43, IQR: 35-40), other anxiety disorders (24-50, IQR: 31-41), and substance use disorders (18-29, IQR: 21-26). Median and IQR lifetime prevalence estimates are: anxiety disorders 4.8-31.0% (IQR: 9.9-16.7%), mood disorders 3.3-21.4% (IQR: 9.8-15.8%), impulse control disorders 0.3-25.0% (IQR: 3.1-5.7%), substance use disorders 1.3-15.0% (IQR: 4.8-9.6%), and any disorder 12.0-47.4% (IQR: 18.1-36.1%). Projected lifetime risk is proportionally between 17% and 69% higher than estimated lifetime prevalence (IQR: 28-44%), with the highest ratios in countries exposed to sectarian violence (Israel, Nigeria, and South Africa), and a general tendency for projected risk to be highest in recent cohorts in all countries. These results document clearly that mental disorders are commonly occurring. As many mental disorders begin in childhood or adolescents, interventions aimed at early detection and treatment might help reduce the persistence or severity of primary disorders and prevent the subsequent onset of secondary disorders.     

Influence of temperature on the spatial distribution of first spawning dates of the common frog (Rana temporaria) in the UK

Between 1998 and 2007, the UK Phenology Network collected nearly 70 000 records of the first spawn dates of the common frog Rana temporaria . Annual national mean dates varied by more than 2 weeks and were closely related to January–March temperatures. A 1 °C increase in Central England Temperature advanced national mean spawning by 5.1 days. The temporal pattern of spawning records varied between years; sometimes unimodal in form, sometimes multimodal, seemingly associated with steady or erratic rises in spring temperatures, respectively. Spatial patterns of frogspawn were similar in different years, the earliest records occurring in the southwest with records progressively later in the north and east. On average, 100 km of eastwards progression took 7.4 days and 100 km of northwards progression took 4.7 days. A composite map for the 1998–2007 period is constructed and compared with an earlier published map based on data 60 years previously. The similarity and dissimilarity of these two maps is discussed; the general progression pattern of frogspawn phenology is similar but an advance of a 10-day contour category is apparent. We anticipate further advances of frog spawning dates in the future and an increase in the numbers of pre-January 1 records of frog breeding.     

Differences in biometrics and moult of non-breeding Red Knots Calidris canutus in southern Africa and Scotland reflect contrasting climatic conditions

We describe the migration, biometrics and moult of Red Knot Calidris canutus canutus in southern Africa and compare them with the biometrics and moult of Calidris canutus islandica in northern Europe to examine possible adaptations to different environments during the non‐breeding season. Northward and southward migration of C. c. canutus took place along the coast of Western Europe and there was one recovery in West Africa (Mauritania), suggesting a coastal migration round West Africa rather than migration across the Sahara, as recorded in other waders. Adult Knots in South Africa had no additional fattening in November–January (fat index of 7%), in contrast to C. c. islandica wintering in Britain. This is consistent with the theory that extra fat is required only where food shortages are likely. The bills of canutus were longer than those of islandica but their wings were shorter, confirming the sub‐specific assignments and origin of this population. The average duration of primary moult in South Africa was 95 days, shorter than that of other Arctic‐breeding waders that moult in South Africa, but longer than of islandica moulting in Scotland (77 days). Mean starting and completion dates were 20 July and 5 October for islandica and 25 October and 28 January for canutus. The timing and duration of primary moult for these two subspecies suggest that waders need to complete moult before the northern winter when food supplies are limited, whilst waders in benign climates face no such pressures. First‐year canutus either retained old primaries for much of their first year or had a partial moult of inner or other primaries. Adults departed on northward migration in mid‐April, having attained a mean departure mass of c. 190 g (maximum 232 g). The mean fat index at this time was 24% (maximum 29%) and the fat‐free flight muscle mass increased. The predicted flight range of 4000 km falls short of the distance to the first likely refuelling site in West Africa, suggesting that birds rely on assistance from favourable winds.     

Optimizing resiliency of reserve networks to climate change: multispecies conservation planning in the Pacific Northwest,USA

The effectiveness of a system of reserves may be compromised under climate change as species' habitat shifts to nonreserved areas, a problem that may be compounded when well‐studied vertebrate species are used as conservation umbrellas for other taxa. The Northwest Forest Plan was among the first efforts to integrate conservation of wide‐ranging focal species and localized endemics into regional conservation planning. We evaluated how effectively the plan's focal species, the Northern Spotted Owl, acts as an umbrella for localized species under current and projected future climates and how the regional system of reserves can be made more resilient to climate change. We used the program maxent to develop distribution models integrating climate data with vegetation variables for the owl and 130 localized species. We used the program zonation to identify a system of areas that efficiently captures habitat for both the owl and localized species and prioritizes refugial areas of climatic and topographic heterogeneity where current and future habitat for dispersal‐limited species is in proximity. We projected future species' distributions based on an ensemble of contrasting climate models, and incorporating uncertainty between alternate climate projections into the prioritization process. Reserve solutions based on the owl overlap areas of high localized‐species richness but poorly capture core areas of localized species' distribution. Congruence between priority areas across taxa increases when refugial areas are prioritized. Although core‐area selection strategies can potentially increase the conservation value and resilience of regional reserve systems, they accentuate contrasts in priority areas between species and over time and should be combined with a broadened taxonomic scope and increased attention to potential effects of climate change. Our results suggest that systems of fixed reserves designed for resilience can increase the likelihood of retaining the biological diversity of forest ecosystems under climate change.     

PROBLEMS OF THE ORIGIN OF REPTILES

The fossil records of the four living reptilian orders can be traced into the Triassic. The earlier ancestry of the turtles has not been established. Squamates and rhyncho-cephalians evolved from the Late Permian eosuchians; crocodiles from the thecodonts. The ancestry of the eosuchians and thecodonts is to be found in the central stock of Permo-Carboniferous reptiles, the captorhinomorphs. The earliest captorhino-morphs, from the Lower Pennsylvanian, are already fully developed reptiles. The limnoscelids and solenodonsaurids are more primitive forms, retaining features typical of anthracosaurian amphibians. Neither reptiles nor any appropriate ancestors are known prior to the Lower Pennsylvanian. Because of the absence of any true ancestors, the nature of the amphibian-reptilian transition must be studied on the basis of amphibians contemporary with the early reptiles. The Permian seymouriamorphs have long been accepted as relicts of the group which gave rise to reptiles, although Seymouria itself is specialized in many features of its anatomy. The Middle Pennsylvanian genus Gephyrostegus appears to resemble much more closely the anatomy expected in the ancestors of reptiles. This genus forms the basis for consideration of the anatomical, physiological and behavioural changes which culminated in the origin of reptiles. Study of the earliest known reptiles and their closest relatives among contemporary amphibians indicates that the initial adaptation leading to the emergence of the class was assumption of a terrestrial habit, with accompanying small body size. The small body size of the immediate ancestors of reptiles would have made it possible for them to produce sufficiently small eggs that they could develop in damp places on land without initially being supported and protected by extraembryonic membranes. The rapid increase in body size in all lineages of Pennsylvanian reptiles indicates the prior development of an amniotic egg. Fundamental to the emergence of reptiles was modification in the jaw mechanism from the kinetic inertial system of amphibians to a static pressure system. The latter was presumably developed in order for the developing reptiles to utilize more active terrestrial prey. This change in the jaw mechanism is reflected in the reorganization of the palate which serves as a morphological basis for denning the establishment of reptilian status. At approximately the same stage as the change in palatal structure, the definitive reptilian vertebral pattern was developed. The apparent closure of the otic notch and the probable reorientation of the stapes in the amphibian-reptilian transition presumably resulted from the decrease in relative skull size and do not appear to be related to any change in hearing ability. The tympanum probably maintained the same relative relationship with the squamosal and supratemporal throughout this transition. On the basis of the present fossil record, all adequately known Palaeozoic reptiles appear to have had a common ancestry among the predecessors of the known gephyro-stegids. The family Diadectidae is the only important group whose specific relationships cannot be established. On the basis of this study, the following taxonomic changes are suggested: the family Limnoscelidae should not be included among the captorhinomorphs. The seymouria-morph concept should be restricted to forms having the specializations of Seymouria, the discosauriscids and kotlassids. Gephyrostegids should be specifically excluded from the Seymouriamorpha and should be included in a separate taxon among the anthra-cosaurs of equal rank with embolomeres and seymouriamorphs.     

Detection of bean yellow mosaic virus in gladioli corms by the polymerase chain reaction

The polymerase chain reaction (PCR) method readily detected bean yellow mosaic virus (BYMV) in gladioli leaves, but in initial tests PCR did not detect virus in corm tissue. Extracts of RN A from corm tissue were shown to inhibit the amplification of viral sequences when added to a PCR reaction. An additional purification step for the RNA extracts using a Sephadex G-50 column eliminated the inhibitory effect and enabled PCR to amplify and detect viral RNA in corm tissue preparations.     

Effects of long‐term fox baiting on species composition and abundance in an Australian lizard community

Abstract We report on the effects of almost a decade of 1080‐fox baiting on a lizard community in a mosaic Australian habitat. Replicated comparisons of baited versus non‐baited control areas with near‐identical histories of bush fires, grazing and climate showed a higher density of red fox tracks (Canis vulpes) in the non‐baited areas. Furthermore, the fox‐baited areas showed a more than five times higher density of sand goannas (Varanus gouldii), a species that strongly overlaps the red fox in food niche breadth and is itself a direct target of fox predation, in particular its eggs and young. Exclusion of predators from a natural habitat led to significant increases in the density of small lizards, suggesting that predation can drive lizard population dynamics in this ecosystem. Replicated pitfall‐trapping in three habitats in the control areas (with high fox and low goanna density) versus the baited areas (with low fox and high goanna density) showed that fox baiting had positive effects on the density of diurnal scincid lizards in open grassland, whereas the control areas showed higher density of nocturnal gecko lizards. Our interpretation is that fox removal may result in a shift in the top predator towards the sand goanna. Historically, this indigenous, endemic species was the natural top predator. It has co‐evolved with its prey and that may have moulded it into a more efficient lizard predator per encounter than the introduced fox.     

Interannual climatic variation mediates elevated CO2 and O3 effects on forest growth

We analyzed growth data from model aspen (Populus tremuloides Michx.) forest ecosystems grown in elevated atmospheric carbon dioxide ([CO₂]; 518 μL L^?1) and ozone concentrations ([O₃]; 1.5 × background of 30–40 nL L^?1 during daylight hours) for 7 years using free‐air CO₂ enrichment technology to determine how interannual variability in present‐day climate might affect growth responses to either gas. We also tested whether growth effects of those gasses were sustained over time. Elevated [CO₂] increased tree heights, diameters, and main stem volumes by 11%, 16%, and 20%, respectively, whereas elevated ozone [O₃] decreased them by 11%, 8%, and 29%, respectively. Responses similar to these were found for stand volume and basal area. There were no growth responses to the combination of elevated [CO₂+O₃]. The elevated [CO₂] growth stimulation was found to be decreasing, but relative growth rates varied considerably from year to year. Neither the variation in annual relative growth rates nor the apparent decline in CO₂ growth response could be explained in terms of nitrogen or water limitations. Instead, growth responses to elevated [CO₂] and [O₃] interacted strongly with present‐day interannual variability in climatic conditions. The amount of photosynthetically active radiation and temperature during specific times of the year coinciding with growth phenology explained 20–63% of the annual variation in growth response to elevated [CO₂] and [O₃]. Years with higher photosynthetic photon flux (PPF) during the month of July resulted in more positive growth responses to elevated [CO₂] and more negative growth responses to elevated [O₃]. Mean daily temperatures during the month of October affected growth in a similar fashion the following year. These results indicate that a several‐year trend of increasingly cloudy summers and cool autumns were responsible for the decrease in CO₂ growth response.