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Background A better understanding of the physiological response of silage maize to a mild reduction in nitrogen(N) fertilization and the identification of predictive biochemical markers of N utilization efficiency could contribute to limit the detrimental effect of the overuse of N inputs. Results To identify predictive biochemical markers of nitrogen (N) utilization and metabolism of silage maize in relation to growth and productivity, a metabolomic and a proteomic approach were combined. These analyses were performed on young leaves of a core panel of 29 European genetically diverse dent hybrids cultivated in the field under non-limiting and reduced N fertilization conditions in order to identify such predictive markers at an early stage of plant development. Metabolome and proteome data were analyzed either individually or in an integrated manner together with eco-physiological, developmental and yield-related traits. These analyses allowed to depict the physiology underlying plant response to the mild N deficit often occurring when maize is grown under agronomic conditions. Moreover, the genetic diversity of the 29 hybrids was exploited to identify common N-responsive metabolites and protein that could be used as predictive markers to monitor N fertilization and to identify silage maize hybrids representing possible ideotypes that exhibit improved agronomic performance when N fertilization is reduced. Conclusion Among the N-responsive metabolites and proteins identified, a cytosolic NADP-dependent malic enzyme and four metabolite signatures stand out as promising markers that could be used for both breeding and agronomic purposes.

In Northern Europe, sowing maize one‐month earlier than current agricultural practices may lead to moderate chilling damage. However, studies of the metabolic responses to low, non‐freezing, temperatures remain scarce. Here, genetically‐diverse maize hybrids (Zea mays, dent inbred lines crossed with a flint inbred line) were cultivated in a growth chamber at optimal temperature and then three decreasing temperatures for 2 days each, as well as in the field. Leaf metabolomic and proteomic profiles were determined. In the growth chamber, 50% of metabolites and 18% of proteins changed between 20 and 16°C. These maize responses, partly differing from those of Arabidopsis to short‐term chilling, were mapped on genome‐wide metabolic maps. Several metabolites and proteins showed similar variation for all temperature decreases: seven MS‐based metabolite signatures and two proteins involved in photosynthesis decreased continuously. Several increasing metabolites or proteins in the growth‐chamber chilling conditions showed similar trends in the early‐sowing field experiment, including trans‐aconitate, three hydroxycinnamate derivatives, a benzoxazinoid, a sucrose synthase, lethal leaf‐spot 1 protein, an allene oxide synthase, several glutathione transferases and peroxidases. Hybrid groups based on field biomass were used to search for the metabolite or protein responses differentiating them in growth‐chamber conditions, which could be of interest for breeding., Metabolomic and proteomic responses of diverse maize hybrids to progressive decreasing temperatures were larger from 20 to 16°C, partly mimicked those in the field, and involved primary and specialized metabolisms.

Plant and crop metabolomic analyses may be used to study metabolism across genetic and environmental diversity. Complementary analytical strategies are useful for investigating metabolic changes and searching for biomarkers of response or performance., The experimental material consisted in eight sunflower lines with two line status, four restorers (R, used as males) and four maintainers (B, corresponding to females) routinely used for sunflower hybrid varietal production, respectively to complement or maintain the cytoplasmic male sterility PET1. These lines were either irrigated at full soil capacity (WW) or submitted to drought stress (DS). Our aim was to combine targeted and non-targeted metabolomics to characterize sunflower leaf composition in order to investigate the effect of line status genotypes and environmental conditions and to find the best and smallest set of biomarkers for line status and stress response using a custom-made process of variables selection., H-NMR, MS-based profiles and targeted analyses of major metabolites. Based on statistical analyses, a limited number of markers were able to separate WW and DS samples in a more discriminant manner than previously published physiological data. Another metabolic marker set was able to discriminate line status., This study underlines the potential of metabolic markers for discriminating genotype groups and environmental conditions. Their potential use for prediction is discussed.

Introduction In Northern Europe, maize early-sowing used to maximize yield may lead to moderate damages of seedlings due to chilling without visual phenotypes. Genetic studies and breeding for chilling tolerance remain necessary, and metabolic markers would be particularly useful in this context. Objectives Using an untargeted metabolomic approach on a collection of maize hybrids, our aim was to identify metabolite signatures and/or metabolites associated with chilling responses at the vegetative stage, to search for metabolites differentiating groups of hybrids based on silage-earliness, and to search for marker-metabolites correlated with aerial biomass. Methods Thirty genetically-diverse maize dent inbred-lines (Zea mays) crossed to a flint inbred-line were sown in a field to assess metabolite profiles upon cold treatment induced by a modification of sowing date, and characterized with climatic measurements and phenotyping. Results NMR- and LC-MS-based metabolomic profiling revealed the biological variation of primary and specialized metabolites in young leaves of plants before flowering-stage. The effect of early-sowing on leaf composition was larger than that of genotype, and several metabolites were associated to sowing response. The metabolic distances between genotypes based on leaf compositional data were not related to the genotype admixture groups, and their variability was lower under early-sowing than normal-sowing. Several metabolites or metabolite-features were related to silage-earliness groups in the normal-sowing condition, some of which were confirmed the following year. Correlation networks involving metabolites and aerial biomass suggested marker-metabolites for breeding for chilling tolerance. Conclusion After validation in other experiments and larger genotype panels, these marker-metabolites can contribute to breeding. Electronic supplementary material The online version of this article (10.1007/s11306-018-1427-8) contains supplementary material, which is available to authorized users.

International audience; Background: In the last decade, metabolomics has emerged as a powerful diagnostic and predictive tool in many branches of science. Researchers in microbes, animal, food, medical and plant science have generated a large number of targeted or non-targeted metabolic profiles by using a vast array of analytical methods (GC–MS, LC–MS, 1H-NMR….). Comprehensive analysis of such profiles using adapted statistical methods and modeling has opened up the possibility of using single or combinations of metabolites as markers. Metabolic markers have been proposed as proxy, diagnostic or predictors of key traits in a range of model species and accurate predictions of disease outbreak frequency, developmental stages, food sensory evaluation and crop yield have been obtained. Aim of review : (i) To provide a definition of plant performance and metabolic markers, (ii) to highlight recent key applications involving metabolic markers as tools for monitoring or predicting plant performance, and (iii) to propose a workable and cost-efficient pipeline to generate and use metabolic markers with a special focus on plant breeding. Key message: Using examples in other models and domains, the review proposes that metabolic markers are tending to complement and possibly replace traditional molecular markers in plant science as efficient estimators of performance.

The jungle of Cusco forms part of the ecosystem of the Amazon and is one of the áreas with greatest biodiversity in the planet. Therefore, one of the greatest challenges for Transportadora de Gas del Peru (TgP) was to develop -and afterwards, operate-such a complex project in harmony with the environment and without affecting the quality of life of the inhabitants of the area. Conscious of this responsibility, TgP has decided to implement a set of measures to prevent, control, and mitigate the possible environmental impacts of its activities; while having the support and involvement of the communities. Thus, the Community Environmental Monitoring Program was born (PMAC-AU). PMAC-AU is an independent and original program -in its application within the hydrocarbon sector- with the goal to promote the effective participation of native communities and rural population of the area of direct influence of TgP’s Pipeline Transportation System in the social and environmental watch of the activities carried out by the company; and, at the same time, to strengthen bonds of trust and transparency between the company and the community. By implementing participatory workshops, community monitors are trained by a specialized technical entity - other than TgP- in order to identify and act in a timely manner while facing possible environmental and social impacts; as well as to guarantee transparency in the activities carried out by the company. The monitors are chosen in a voluntary and independent fashion by their communities of origin. Additionally, each monitor disseminates the results of the monitoring in their respective communities, strengthening their leadership capacities, and turning them into agents of change within their communities. The PMAC has worked in a continuous manner for more than 8 years, which shows the commitment of communities with the program. Likewise, by the end of 2011, 100% of the observations registered by the PMAC have been addressed by TgP, which reveals the commitment between company and community in order to mitigate and prevent any potential socioeconomic impact. In this fashion, TgP has managed to establish relationships of trust and cooperation with the native communities in the areas of influence.

The objectives of the present work were to detect Leptospira seropositive animals. The ELISA results report only IgG antibodies, which could be attributable to chronic infections or else, that they are healthy carriers. All polymerase chain reaction positive animals should be considered potential sources of infection.