Project description:Climate change forecasts increase the susceptibility of forest due to longer drier seasons. The adaptive management protocols have highlighted the reduction of the forest densification to improve their vulnerability to extreme climate events (i.g. drought). One of this sensitive woody species to climate change is the Abies pinsapo, a relic conifer tree endemic from the southern Spain. Previous works have shown changes in their trends because of the climate change action, being carried out experimental thinning management in their lowest distribution limit, in Sierra de las Nieves Natural Park (Malaga). Our objective is to evaluate the water improvements of thinned trees in terms of light availability by means of a shading treatment in those thinned trees. To do that we have evaluated the synergic effect of ecophysiology, metabolomics and transcriptomics in control, thinning and thinning+shading plots in wet and dry seasons for two years. The results showed strong differences between summer and spring seasons at the three studied levels. The water deficit shows a greater influence than light exposure in the ecophysiology and metabolomics tree response. And the transcriptomics suggested an improvement of thinned trees when light exposure was reduced. Our results support the necessity of adaptive forest management in order to improve the conservation status of A. pinsapo forest. The combination of different levels of tree response is paramount to understand and predict the tree physiology under water and light stress conditions.
Project description:Predicting how climate change affects biotic interactions and their evolution poses a challenge. Plant-insect herbivore interactions are particularly sensitive to climate change, as climate-induced changes in plant quality cascade into the performance of insect herbivores. Whereas the immediate survival of herbivore individuals depends on plastic responses to climate change induced nutritional stress, long-term population persistence via evolutionary adaptation requires genetic variation for these responses. In order to assess the prospects for population persistence under climate change, it is therefore crucial to characterise response mechanisms to climate change induced stressors, and quantify their variability in natural populations. Here, we test developmental and transcriptomic responses to water limitation induced host plant quality change in a Glanville fritillary butterfly (Melitaea cinxia) metapopulation. We combine nuclear magnetic resonance spectroscopy on the plant metabolome, larval developmental assays and an RNA seq analysis of the larval transcriptome. We observed that responses to feeding on water limited plants, in which amino acids and aromatic compounds are enriched, showed marked intrapopulation variation, with individuals of some families performing better on control and others on water limited plants. The transcriptomic responses were concordant with the developmental responses: Families exhibiting opposite developmental responses also produced opposite transcriptomic responses, e.g. in growth associated intracellular signalling. The opposite developmental and transcriptomic responses are associated with between families differences in organic compound catabolism and storage protein production. The results reveal heritable intrapopulation variability in plasticity, suggesting potential for evolutionary responses to drought-induced changes in host plant quality in the Finnish M. cinxia metapopulation.
Project description:Soil microbial community is a complex blackbox that requires a multi-conceptual approach (Hultman et al., 2015; Bastida et al., 2016). Most methods focus on evaluating total microbial community and fail to determine its active fraction (Blagodatskaya & Kuzyakov 2013). This issue has ecological consequences since the behavior of the active community is more important (or even essential) and can be different to that of the total community. The sensitivity of the active microbial community can be considered as a biological mechanism that regulates the functional responses of soil against direct (i.e. forest management) and indirect (i.e. climate change) human-induced alterations. Indeed, it has been highglihted that the diversity of the active community (analyzed by metaproteomics) is more connected to soil functionality than the that of the total community (analyzed by 16S rRNA gene and ITS sequencing) (Bastida et al., 2016). Recently, the increasing application of soil metaproteomics is providing unprecedented, in-depth characterisation of the composition and functionality of active microbial communities and overall, allowing deeper insights into terrestrial microbial ecology (Chourey et al., 2012; Bastida et al., 2015, 2016; Keiblinger et al., 2016). Here, we predict the responsiveness of the soil microbial community to forest management in a climate change scenario. Particularly, we aim: i) to evaluate the impacts of 6-years of induced drought on the diversity, biomass and activity of the microbial community in a semiarid forest ecocosystem; and ii) to discriminate if forest management (thinning) influences the resistance of the microbial community against induced drought. Furthermore, we aim to ascertain if the functional diversity of each phylum is a trait that can be used to predict changes in microbial abundance and ecosystem functioning.
Project description:Projected responses of ocean net primary productivity (NPP) to climate change are highly uncertain. The climate sensitivity of phytoplankton nutrient limitation in the low-latitude Pacific plays a crucial role, but field measurements are insufficient to provide suitable constraints. Here we quantify two decades of nutrient limitation in the Equatorial Pacific with satellite observations. Using field nutrient addition experiments, proteomics, and above-water hyperspectral radiometry, we demonstrate that physiological responses of phytoplankton to iron limitation led to ~3-fold increases in chlorophyll-normalized phytoplankton fluorescence. Extension to the >18-year satellite fluorescence record showed that Equatorial Pacific iron limitation was robust to changes in physical forcing through multiple El Niño–Southern Oscillation cycles, despite coherent fluctuations in limitation strength. In contrast, these iron limitation changes were overestimated 2-fold by a state-of-the-art climate model. Such synoptic constraints provide a powerful new approach for benchmarking the realism of model NPP projections to climate changes.
Project description:The response of soil microbial community to climate warming through both function shift and composition reorganization may profoundly influence global nutrient cycles, leading to potential significant carbon release from the terrain to the atmosphere. Despite the observed carbon flux change in northern permafrost, it remains unclear how soil microbial community contributes to this ecosystem alteration. Here, we applied microarray-based GeoChip 4.0 to investigate the functional and compositional response of subsurface (15~25cm) soil microbial community under about one year’s artificial heating (+2°C) in the Carbon in Permafrost Experimental Heating Research site on Alaska’s moist acidic tundra. Statistical analyses of GeoChip signal intensities showed significant microbial function shift in AK samples. Detrended correspondence analysis and dissimilarity tests (MRPP and ANOSIM) indicated significant functional structure difference between the warmed and the control communities. ANOVA revealed that 60% of the 70 detected individual genes in carbon, nitrogen, phosphorous and sulfur cyclings were substantially increased (p<0.05) by heating. 18 out of 33 detected carbon degradation genes were more abundant in warming samples in AK site, regardless of the discrepancy of labile or recalcitrant C, indicating a high temperature sensitivity of carbon degradation genes in rich carbon pool environment. These results demonstrated a rapid response of northern permafrost soil microbial community to warming. Considering the large carbon storage in northern permafrost region, microbial activity in this region may cause dramatic positive feedback to climate change, which is important and necessary to be integrated into climate change models.
Project description:GCMS datasets for the soil depth manuscript
Abstract
Two factors that are well-known to influence soil microbiomes include the depth of the soil as well as the level of moisture. Previous works have demonstrated that climate change will increase the incidence of drought in soils, but it is unknown how fluctuations in moisture availability affect soil microbiome composition and functioning down the depth profile. Here, we investigated soil and wheatgrass rhizosphere microbiomes in a common field setting under four different irrigation regimes and three depths. We demonstrated that there is a significant interactive effect, where fluctuations in soil moisture more strongly influence soil microbiomes at the surface layer than in deeper layers, including for soil community composition, diversity, and for functional profiles. Meanwhile, in rhizosphere communities the influence of irrigation was similar across the different depths, although there were slight discrepancies between the two cultivars of wheatgrass used. The lessened response of deeper soil microbiomes to changes in irrigation may be due to higher incidence of slow-growing, stress-resistant microbes.
Project description:Alginate, a major exopolysaccharide (EPS) produced by P. putida, is known to create hydrated environments and alleviate the effect of water limitation. In addition to alginate, P. putida is capable of producing cellulose (bcs), putida exopolysaccharide a (pea), and putida exopolysaccharide b (peb). However, unlike alginate, not much is known about their roles under water limitation. Hence, in this study we examined the role of different EPS under water stress. To create environmentally realistic water stress conditions as observed in soil, we used Pressurized Porous Surface Model (PPSM). Our main hypothesis was that under water stress, absence of alginate would be compensated by the other EPS. To test our hypothesis, we investigated colony morphologies and whole genome transcriptomes of P. putida KT2440 WT and its mutants deficient in either alginate or all known EPS
Project description:Climate change is increasing the frequency and intensity of warming and drought periods around the globe, currently representing a threat to many plant species. Understanding the resistance and resilience of plants to climate change is, therefore, urgently needed. As date palm (Phoenix dactylifera) evolved adaptation mechanisms to a xeric environment and is able to tolerate large diurnal and seasonal temperature fluctuations, we studied the protein expression changes in their leaves, volatile organic compound emissions, and photosynthesis in response to variable growth temperatures and soil water deprivation. Plants were grown under controlled environmental conditions under simulated Saudi Arabian summer and winter climates followed by drought stress. We show that date palm is able to counteract the harsh conditions of the Arabian Peninsula by adjusting the abundances of proteins related to the photosynthetic machinery, abiotic stress and secondary metabolism. Under summer climate and water deprivation, these adjustments included efficient protein expression response mediated by heat shock proteins and the antioxidant system to counteract reactive oxygen species formation. Proteins related to secondary metabolism were downregulated, except for the P. dactylifera isoprene synthase (PdIspS), which was strongly upregulated in response to summer climate and drought. This study reports for the first time, the identification and functional characterization of the gene encoding for PdIspS, allowing future analysis of isoprene functions in date palm under extreme environments. Overall, the current results show that protein reprogramming of date palm leaves contribute to heat and drought tolerance. We conclude that the protein plasticity of date palm is one important mechanism of molecular adaptation to remarkable environmental fluctuations.
Project description:The experiment at three long-term agricultural experimental stations (namely the N, M and S sites) across northeast to southeast China was setup and operated by the Institute of Soil Science, Chinese Academy of Sciences. This experiment belongs to an integrated project (The Soil Reciprocal Transplant Experiment, SRTE) which serves as a platform for a number of studies evaluating climate and cropping effects on soil microbial diversity and its agro-ecosystem functioning. Soil transplant serves as a proxy to simulate climate change in realistic climate regimes. Here, we assessed the effects of soil type, soil transplant and landuse changes on soil microbial communities, which are key drivers in Earth’s biogeochemical cycles.
Project description:We measured transcriptional profiles of individuals of Andropogon gerardii, a C4 grass native to North American grasslands, in a field experiment in which both temperature and precipitation have been manipulated to simulate key aspects of forecasted climate change. By using microarrays developed for a closely related model species, Zea mays, we were able to compare the relative influence of warming versus altered soil moisture availability on expression levels of over 7,000 genes. The plants were located in 12 experimental plots under rainout shelters on the Konza Prairie Biological Station in Manhattan, Kansas.