How woody plants adjust above- and below-ground traits in response to sustained drought

This is the final version. Available on open access from Wiley via the DOI in this recordFuture increases in drought severity and frequency are predicted to have substantial impacts on plant function and survival. However, there is considerable uncertainty concerning what drought adjustment is and whether plants can adjust to sustained drought. This review focuses on woody plants and synthesises the evidence for drought adjustment in a selection of key above-ground and below-ground plant traits. We assess whether evaluating the drought adjustment of single traits, or selections of traits that operate on the same plant functional axis (e.g. photosynthetic traits) is sufficient, or whether a multi-trait approach, integrating across multiple axes, is required. We conclude that studies on drought adjustments in woody plants might overestimate the capacity for adjustment to drier environments if spatial studies along gradients are used, without complementary experimental approaches. We provide evidence that drought adjustment is common in above-ground and below-ground traits; however, whether this is adaptive and sufficient to respond to future droughts remains uncertain for most species. To address this uncertainty, we must move towards studying trait integration within and across multiple axes of plant function (e.g. above-ground and below-ground) to gain a holistic view of drought adjustments at the whole-plant scale and how these influence plant survival.Natural Environment Research Council (NERC)MINECOEuropean Union Horizon 202

In vitro and in vivo effects of lutein against cisplatin-induced ototoxicity

This is peer reviewed version of the following article Experimental and Toxicologic Pathology 68.4 (2016): 197-204, which has been published in final form at http://dx.doi.org/10.1016/j.etp.2016.01.003Introduction: Cisplatin is a commonly prescribed drug that produces ototoxicity as a side effect. Lutein is a carotenoid with antioxidant and anti-inflammatory properties previously tested for eye, heart and skin diseases but not evaluated to date in ear diseases. Aim: To evaluate the protective effects of lutein on HEI-OC1 auditory cell line and in a Wistar rat model of cisplatin ototoxicity. Materials and Methods: In vitro study: Culture HEI-OC1 cells were exposed to lutein (2.5-100 μM) and to 25 μM cisplatin for 24 h. In vivo study: Twenty eight female Wistar rats were randomized into three groups. Group A (n = 8) received intratympanic lutein (0.03 mL) (1 mg/mL) in the right ear and saline solution in the left one to determine the toxicity of lutein. Group B (n = 8) received also intraperitoneal cisplatin (10 mg/kg) to test the efficacy of lutein against cisplatin ototoxicity. Group C (n = 12) received intratympanic lutein (0.03 mL) (1 mg/mL) to quantify lutein in cochlear fluids (30 min, 1 h and 5 days after treatment). Hearing function was evaluated by means of Auditory Steady-State Responses before the procedure and 5 days after (groups A and B). Morphological changes were studied by confocal laser scanning microscopy. Results: In vitro study: Lutein significantly reduced the cisplatin-induced cytotoxicity in the HEI-OC1 cells when they were pre-treated with lutein concentrations of 60 and 80 μM. In vivo study: Intratympanic lutein (1 mg/mL) application showed no ototoxic effects. However it did not achieve protective effect against cisplatin-induced ototoxicity in Wistar rats. Conclusions: Although lutein has shown beneficial effects in other pathologies, the present study only obtained protection against cisplatin ototoxicity in culture cells, but not in the in vivo model. The large molecule size, the low dose administered, and restriction to diffusion in the inner ear could account for this negative result.Research supported by a Spanish FIS Grant EI 11/00742

Late Quaternary evolution of alluvial fans in the Playa, El Fresnal region, northern Chihuahua desert, Mexico: Palaeoclimatic implications

The Playa El Fresnal area is a tilted terrane characteristic of an extensional basin. It is a half graben/tilted-block system with a playa-lake on the basin floor flanked by piedmonts covered by alluvial fans. Structural heterogeneities within normal fault zones influenced the geomorphic expression of the uplifted footwall blocks of associated volcanism, and the downdropped hanging wall. The footwall area is the main sediment source, but the hanging wall-derived sediments are more extensive. The ancient alluvial fans are in the distal part, whereas the hanging-wall sediments are located in the apex area. A geomorphic analysis of the relative topographic position of the alluvial fans, degree of dissection of the original surfaces, general sedimentology (facies description), and stream channel network type, highlights the importance of climatic change in interpreting alluvial-fan surfaces. Three generations of alluvial fans were identified on the footwall and hanging wall slopes. They were formed during the late Quaternary climatic shift, consistent with the main climatic changes recorded in the paleolake stratig-raphy of northern Mexico and the American Southwest. These alluvial fans consist mainly of debris-flow deposits from flash floods, probably triggered by a change from relatively moist to arid conditions. They contrast with the typically lower-flow-regime of thick-bedded, cross-bedded, and lenticular channel facies, and associated floodplain sequences of rivers

Late Quaternary evolution of alluvial fans in the Playa, El Fresnal region, northern Chihuahua desert, Mexico: Palaeoclimatic implications

The Playa El Fresnal area is a tilted terrane characteristic of an extensional basin. It is a half graben/tilted-block system with a playa-lake on the basin floor flanked by piedmonts covered by alluvial fans. Structural heterogeneities within normal fault zones influenced the geomorphic expression of the uplifted footwall blocks of associated volcanism, and the downdropped hanging wall. The footwall area is the main sediment source, but the hanging wall-derived sediments are more extensive. The ancient alluvial fans are in the distal part, whereas the hanging-wall sediments are located in the apex area. A geomorphic analysis of the relative topographic position of the alluvial fans, degree of dissection of the original surfaces, general sedimentology (facies description), and stream channel network type, highlights the importance of climatic change in interpreting alluvial-fan surfaces. Three generations of alluvial fans were identified on the footwall and hanging wall slopes. They were formed during the late Quaternary climatic shift, consistent with the main climatic changes recorded in the paleolake stratig-raphy of northern Mexico and the American Southwest. These alluvial fans consist mainly of debris-flow deposits from flash floods, probably triggered by a change from relatively moist to arid conditions. They contrast with the typically lower-flow-regime of thick-bedded, cross-bedded, and lenticular channel facies, and associated floodplain sequences of rivers

Natural selection on cork oak: allele frequency reveals divergent selection in cork oak populations along a temperature cline

A recent study of population divergence at neutral markers and adaptive traits in cork oak has observed an association between genetic distances at locus QpZAG46 and genetic distances for leaf size and growth. In that study it was proposed that certain loci could be linked to genes encoding for adaptive traits in cork oak and, thus, could be used in adaptation studies. In order to investigate this hypothesis, here we (1) looked for associations between molecular markers and a set of adaptive traits in cork oak, and (2) explored the effects of the climate on among-population patterns in adaptive traits and molecular markers. For this purpose, we chose 9-year-old plants originating from thirteen populations spanning a broad range of climatic conditions. Plants established in a common garden site were genotyped at six nuclear microsatellites and phenotypically characterized for six functional traits potentially related to plant performance. Our results supported the proposed linkage between locus QpZAG46 and genes encoding for leaf size and growth. Temperature caused adaptive population divergence in leaf size and growth, which was expressed as differences in the frequencies of the alleles at locus QpZAG46

Beyond species loss: The extinction of ecological interactions in a changing world

© 2014 The Authors. The effects of the present biodiversity crisis have been largely focused on the loss of species. However, a missed component of biodiversity loss that often accompanies or even precedes species disappearance is the extinction of ecological interactions. Here, we propose a novel model that (i) relates the diversity of both species and interactions along a gradient of environmental deterioration and (ii) explores how the rate of loss of ecological functions, and consequently of ecosystem services, can be accelerated or restrained depending on how the rate of species loss covaries with the rate of interactions loss. We find that the loss of species and interactions are decoupled, such that ecological interactions are often lost at a higher rate. This implies that the loss of ecological interactions may occur well before species disappearance, affecting species functionality and ecosystems services at a faster rate than species extinctions. We provide a number of empirical case studies illustrating these points. Our approach emphasizes the importance of focusing on species interactions as the major biodiversity component from which the 'health' of ecosystems depends.Peer Reviewe

Ectomycorrhizal fungal diversity and community structure associated with cork oak in different landscapes

Cork oak (Quercus suber L.) forests play an important ecological and economic role. Ectomycorrhizal fungi (ECMF) are key components for the sustainability and functioning of these ecosystems. The community structure and composition of ECMF associated with Q. suber in different landscapes of distinct Mediterranean bioclimate regions have not previously been compared. In this work, soil samples from cork oak forests residing in different bioclimates (arid, semi-arid, sub-humid, and humid) were collected and surveyed for ectomycorrhizal (ECM) root tips. A global analysis performed on 3565 ECM root tips revealed that the ECMF community is highly enriched in Russula, Tomentella, and Cenoccocum, which correspond to the ECMF genera that mainly contribute to community differences. The ECMF communities from the rainiest and the driest cork oak forests were distinct, with soils from the rainiest climates being more heterogeneous than those from the driest climates. The analyses of several abiotic factors on the ECMF communities revealed that bioclimate, precipitation, soil texture, and forest management strongly influenced ECMF structure. Shifts in ECMF with different hyphal exploration types were also detected among forests, with precipitation, forest system, and soil texture being the main drivers controlling their composition. Understanding the effects of environmental factors on the structuring of ECM communities could be the first step for promoting the sustainability of this threatened ecosystem.This work was supported by Fundacao Ciencia e Tecnologia (FCT/MCTES/PIDDAC, Portugal), under the project (PEst-OE/BIA/UI4046/2014; UID/MULTI/04046/2013) and PhD grant to F.R. (SFRH/BD/86519/2012)

Characterization of the cork oak transcriptome dynamics during acorn development

Background: Cork oak (Quercus suber L.) has a natural distribution across western Mediterranean regions and is a keystone forest tree species in these ecosystems. The fruiting phase is especially critical for its regeneration but the molecular mechanisms underlying the biochemical and physiological changes during cork oak acorn development are poorly understood. In this study, the transcriptome of the cork oak acorn, including the seed, was characterized in five stages of development, from early development to acorn maturation, to identify the dominant processes in each stage and reveal transcripts with important functions in gene expression regulation and response to water. Results: A total of 80,357 expressed sequence tags (ESTs) were de novo assembled from RNA-Seq libraries representative of the several acorn developmental stages. Approximately 7.6 % of the total number of transcripts present in Q. suber transcriptome was identified as acorn specific. The analysis of expression profiles during development returned 2,285 differentially expressed (DE) transcripts, which were clustered into six groups. The stage of development corresponding to the mature acorn exhibited an expression profile markedly different from other stages. Approximately 22 % of the DE transcripts putatively code for transcription factors (TF) or transcriptional regulators, and were found almost equally distributed among the several expression profile clusters, highlighting their major roles in controlling the whole developmental process. On the other hand, carbohydrate metabolism, the biological pathway most represented during acorn development, was especially prevalent in mid to late stages as evidenced by enrichment analysis. We further show that genes related to response to water, water deprivation and transport were mostly represented during the early (S2) and the last stage (S8) of acorn development, when tolerance to water desiccation is possibly critical for acorn viability. Conclusions: To our knowledge this work represents the first report of acorn development transcriptomics in oaks. The obtained results provide novel insights into the developmental biology of cork oak acorns, highlighting transcripts putatively involved in the regulation of the gene expression program and in specific processes likely essential for adaptation. It is expected that this knowledge can be transferred to other oak species of great ecological value.Fundação para a Ciência e a Tecnologi

Local and Landscape Factors Determining Occurrence of Phyllostomid Bats in Tropical Secondary Forests

Neotropical forests are being increasingly replaced by a mosaic of patches of different successional stages, agricultural fields and pasture lands. Consequently, the identification of factors shaping the performance of taxa in anthropogenic landscapes is gaining importance, especially for taxa playing critical roles in ecosystem functioning. As phyllostomid bats provide important ecological services through seed dispersal, pollination and control of animal populations, in this study we assessed the relationships between phyllostomid occurrence and the variation in local and landscape level habitat attributes caused by disturbance. We mist-netted phyllostomids in 12 sites representing 4 successional stages of a tropical dry forest (initial, early, intermediate and late). We also quantitatively characterized the habitat attributes at the local (vegetation structure complexity) and the landscape level (forest cover, area and diversity of patches). Two focal scales were considered for landscape characterization: 500 and 1000 m. During 142 sampling nights, we captured 606 individuals representing 15 species and 4 broad guilds. Variation in phyllostomid assemblages, ensembles and populations was associated with variation in local and landscape habitat attributes, and this association was scale-dependent. Specifically, we found a marked guild-specific response, where the abundance of nectarivores tended to be negatively associated with the mean area of dry forest patches, while the abundance of frugivores was positively associated with the percentage of riparian forest. These results are explained by the prevalence of chiropterophilic species in the dry forest and of chiropterochorous species in the riparian forest. Our results indicate that different vegetation classes, as well as a multi-spatial scale approach must be considered for evaluating bat response to variation in landscape attributes. Moreover, for the long-term conservation of phyllostomids in anthropogenic landscapes, we must realize that the management of the habitat at the landscape level is as important as the conservation of particular forest fragments

Is the interplay between epigenetic markers related to the acclimation of Cork oak plants to high temperatures?

Trees necessarily experience changes in temperature, requiring efficient short-term strategies that become crucial in environmental change adaptability. DNA methylation and histone posttranslational modifications have been shown to play a key role in both epigenetic control and plant functional status under stress by controlling the functional state of chromatin and gene expression. Cork oak (Quercus suber L.) is a key stone of the Mediterranean region, growing at temperatures of 45°C. This species was subjected to a cumulative temperature increase from 25°C to 55°C under laboratory conditions in order to test the hypothesis that epigenetic code is related to heat stress tolerance. Electrolyte leakage increased after 35°C, but all plants survived to 55°C. DNA methylation and acetylated histone H3 (AcH3) levels were monitored by HPCE (high performance capillary electrophoresis), MS-RAPD (methylation-sensitive random-amplified polymorphic DNA) and Protein Gel Blot analysis and the spatial distribution of the modifications was assessed using a confocal microscope. DNA methylation analysed by HPCE revealed an increase at 55°C, while MS-RAPD results pointed to dynamic methylation-demethylation patterns over stress. Protein Gel Blot showed the abundance index of AcH3 decreasing from 25°C to 45°C. The immunohistochemical detection of 5-mC (5-methyl-2'-deoxycytidine) and AcH3 came upon the previous results. These results indicate that epigenetic mechanisms such as DNA methylation and histone H3 acetylation have opposite and particular dynamics that can be crucial for the stepwise establishment of this species into such high stress (55°C), allowing its acclimation and survival. This is the first report that assesses epigenetic regulation in order to investigate heat tolerance in forest trees.This work is supported by FEDER through COMPETE (Programa Operacional Factores de Competitividade) and by the FCT project PTDC/AGR-CFL/ 112996/2009. G. Pinto is hired under the programme Cie ˆncia 2008 (FCT, Portugal), co-funded by the Human Potential Operational Programme (National Strategic Reference Framework 2007–2013) and European Social Fund (EU). FCT supported the fellowship of M.C. Dias (SFRH/BPD/41700/2007). L. Valledor fellow was supported by a Marie Curie Action of the European Union (FP7-PEOPLE-IEF). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.publishe