Ozone pollution will compromise efforts to increase global wheat production

Introduction of high‐performing crop cultivars and crop/soil water management practices that increase the stomatal uptake of carbon dioxide and photosynthesis will be instrumental in realizing the United Nations Sustainable Development Goal (SDG) of achieving food security. To date, however, global assessments of how to increase crop yield have failed to consider the negative effects of tropospheric ozone, a gaseous pollutant that enters the leaf stomatal pores of plants along with carbon dioxide, and is increasing in concentration globally, particularly in rapidly developing countries. Earlier studies have simply estimated that the largest effects are in the areas with the highest ozone concentrations. Using a modelling method that accounts for the effects of soil moisture deficit and meteorological factors on the stomatal uptake of ozone, we show for the first time that ozone impacts on wheat yield are particularly large in humid rain‐fed and irrigated areas of major wheat‐producing countries (e.g. United States, France, India, China and Russia). Averaged over 2010–2012, we estimate that ozone reduces wheat yields by a mean 9.9% in the northern hemisphere and 6.2% in the southern hemisphere, corresponding to some 85 Tg (million tonnes) of lost grain. Total production losses in developing countries receiving Official Development Assistance are 50% higher than those in developed countries, potentially reducing the possibility of achieving UN SDG2. Crucially, our analysis shows that ozone could reduce the potential yield benefits of increasing irrigation usage in response to climate change because added irrigation increases the uptake and subsequent negative effects of the pollutant. We show that mitigation of air pollution in a changing climate could play a vital role in achieving the above‐mentioned UN SDG, while also contributing to other SDGs related to human health and well‐being, ecosystems and climate change.     

Evolutionarily inspired solutions to the crop pollination crisis

The global decline in insect diversity threatens pollination services, potentially impacting crop production and food security. Here, we argue that this looming pollination crisis is generally approached from an ecological standpoint, and that consideration of evolutionary principles offers a novel perspective. First, we outline that wild plant species have overcome ‘pollination crises’ throughout evolutionary history, and show how associated principles can be applied to crop pollination. We then highlight technological advances that can be used to adapt crop flowers for optimal pollination by local wild pollinators, especially by increasing generalization in pollination systems. Thus, synergies among fundamental evolutionary research, genetic engineering, and agro-ecological science provide a promising template for addressing a potential pollination crisis, complementing much-needed strategies focused on pollinator conservation.     

Harnessing the omics revolution to address the global biodiversity crisis

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Microbial processing of plant remains is co‐limited by multiple nutrients in global grasslands

Microbial processing of aggregate‐unprotected organic matter inputs is key for soil fertility, long‐term ecosystem carbon and nutrient sequestration and sustainable agriculture. We investigated the effects of adding multiple nutrients (nitrogen, phosphorus and potassium plus nine essential macro‐ and micro‐nutrients) on decomposition and biochemical transformation of standard plant materials buried in 21 grasslands from four continents. Addition of multiple nutrients weakly but consistently increased decomposition and biochemical transformation of plant remains during the peak‐season, concurrent with changes in microbial exoenzymatic activity. Higher mean annual precipitation and lower mean annual temperature were the main climatic drivers of higher decomposition rates, while biochemical transformation of plant remains was negatively related to temperature of the wettest quarter. Nutrients enhanced decomposition most at cool, high rainfall sites, indicating that in a warmer and drier future fertilized grassland soils will have an even more limited potential for microbial processing of plant remains.     

Ecological advice for the global fisher crisis

Fisheries science was the precursor of population ecology and continues to contribute important theoretical advances. Despite this, fishery scientists have a poor record for applying their insights to real-world fisheries management. Is there a gulf between theory and application or does the high variability inherent in fish populations and complexity of multispecies fisheries demand a different approach to management? Perhaps the solution to the world fisheries crisis is obvious after all?     

生物降解地膜应用与地膜残留污染防控

地膜是农业生产中重要的生产资料之一,过去30多年,地膜用量和农作物覆膜面积一直稳定增长,2014年地膜用量达到了144万t,覆膜面积超过1 800万hm~2,该技术对保障我国农产品安全供给作出了重大贡献。与此同时,地膜残留污染问题越来越严重,一些农田的地膜残留量超过250 kg/hm~2,在我国西北的局部区域,地膜残留已经对农田土壤、作物生长发育、农事作业等造成严重影响和危害。生物降解地膜成为替代普通PE地膜、解决地膜残留污染的一种有效措施和手段,目前生物降解地膜正处于产品研发和评价试验的关键阶段,部分生物降解地膜产品在马铃薯、花生、烟草生产上显示出良好的效果,但总体上还面临巨大挑战,主要包括需要进一步提高地膜产品质量,提高地膜产品破裂和降解可控性,改善地膜的增温保墒能力,实现满足农作物对地膜覆盖功能的要求;此外,需要降低生物降解地膜综合成本,促进生物降解地膜规模化应用。总体上,随着技术进步和农业生产环境的变化,生物降解地膜应用将具有良好的前景。     

Microbial arsenic: from geocycles to genes and enzymes

Arsenic compounds have been abundant at near toxic levels in the environment since the origin of life. In response, microbes have evolved mechanisms for arsenic resistance and enzymes that oxidize As(III) to As(V) or reduce As(V) to As(III). Formation and degradation of organoarsenicals, for example methylarsenic compounds, occur. There is a global arsenic geocycle, where microbial metabolism and mobilization (or immobilization) are important processes. Recent progress in studies of the ars operon (conferring resistance to As(III) and As(V)) in many bacterial types (and related systems in Archaea and yeast) and new understanding of arsenite oxidation and arsenate reduction by respiratory-chain-linked enzyme complexes has been substantial. The DNA sequencing and protein crystal structures have established the convergent evolution of three classes of arsenate reductases (that is classes of arsenate reductases are not of common evolutionary origin). Proposed reaction mechanisms in each case involve three cysteine thiols and S-As bond intermediates, so convergent evolution to similar mechanisms has taken place.     

Microbial production of cyanophycin: From enzymes to biopolymers

Cyanophycin is an attractive biopolymer with chemical and material properties that are suitable for industrial applications in the fields of food, medicine, cosmetics, nutrition, and agriculture. For efficient production of cyanophycin, considerable efforts have been exerted to characterize cyanophycin synthetases (CphAs) and optimize fermentations and downstream processes. In this paper, we review the characteristics of diverse CphAs from cyanobacteria and non-cyanobacteria. Furthermore, strategies for cyanophycin production in microbial strains, including Escherichia coli, Pseudomonas putida, Ralstonia eutropha, Rhizopus oryzae, and Saccharomyces cerevisiae, heterologously expressing different cphA genes are reviewed. Additionally, chemical and material properties of cyanophycin and its derivatives produced through biological or chemical modifications are reviewed in the context of their industrial applications. Finally, future perspectives on microbial production of cyanophycin are provided to improve its cost-effectiveness.     

Human-modified landscapes driving the global primate extinction crisis

The world's primates have been severely impacted in diverse and profound ways by anthropogenic pressures. Here, we evaluate the impact of various infrastructures and human-modified landscapes on spatial patterns of primate species richness, at both global and regional scales. We overlaid the International Union for the Conservation of Nature (IUCN) range maps of 520 primate species and applied a global 100 km² grid. We used structural equation modeling and simultaneous autoregressive models to evaluate direct and indirect effects of six human-altered landscapes variables (i.e., human footprint [HFP], croplands [CROP], road density [ROAD], pasture lands [PAST], protected areas [PAs], and Indigenous Peoples' lands [IPLs]) on global primate species richness, threatened and non-threatened species, as well as on species with decreasing and non-decreasing populations. Two-thirds of all primate species are classified as threatened (i.e., Critically Endangered, Endangered, and Vulnerable), with ~86% experiencing population declines, and ~84% impacted by domestic or international trade. We found that the expansion of PAST, HFP, CROP, and road infrastructure had the most direct negative effects on primate richness. In contrast, forested habitat within IPLs and PAs was positively associated in safeguarding primate species diversity globally, with an even stronger effect at the regional level. Our results show that IPLs and PAs play a critical role in primate species conservation, helping to prevent their extinction; in contrast, HFP growth and expansion has a dramatically negative effect on primate species worldwide. Our findings support predictions that the continued negative impact of anthropogenic pressures on natural habitats may lead to a significant decline in global primate species richness, and likely, species extirpations. We advocate for stronger national and international policy frameworks promoting alternative/sustainable livelihoods and reducing persistent anthropogenic pressures to help mitigate the extinction risk of the world's primate species.     

Microbial response to limited nutrients in shallow water immediately after the end-Permian mass extinction

Previous work indicates that a variety of microbes bloomed in the oceans after the end-Permian faunal mass extinction, but evidence is sporadically documented. Thus, the nature and geographic distribution of such microbes and their associations are unclear, addressed in this study using a series of biomarker groups. On the basis of microbial biomarker records of the 2-methylhopane index, evidence is presented for cyanobacterial blooms in both the western and eastern Tethys Sea and in both shallow and deep waters, after the mass extinction. The enhanced relative abundance of C(28) (expressed by the C(28) /C(29) ratio of) regular steranes suggests a bloom of prasinophyte algae occurred immediately after the end-Permian faunal extinction, comparable with those observed in some other mass extinctions in Phanerozoic. Significantly, cyanobacteria and prasinophyte algae show a synchronized onset of bloom in the shallow water Bulla section, north Italy, inferring for the first time their coupled response to the biotic crisis and the associated environmental conditions. However, in Meishan of Zhejiang Province in south China, the bloom declined earlier than in Bulla. The association of increased 2-methylhopane index with a negative shift in the nitrogen isotope composition infers a scenario of enhanced nitrogen fixation by cyanobacteria immediately after the faunal mass extinction. N(2) fixation by cyanobacteria is here interpreted to have provided prasinophyte algae with ammonium in nutrient-limited shallow waters, and thus caused their associated blooms.     

Migration of phthalates from plastic products to model solutions

The aim of this investigation was to determine the level and rate of migration of phthalates, compounds used as plastic softeners, from various plastic products into model solutions and to assess the possible adverse effects of the phthalate amounts released on human health, thus to contribute to harmonization of the opinions on the maximal allowed human exposure to these compounds through environmental factors. Nine specimens of plastic toys, 16 specimens of plastic food containers and 10 specimens of other plastic consumer goods were analyzed. The specimens of plastic products were submitted to 10-day action of model solutions. Three model solutions were used: distilled water, 10% ethyl alcohol, and 3% acetic acid. Identification and quantification of the phthalates released were performed by the method of gas chromatography on days 1, 5 and 10 of exposure, at a detection limit of 0.005 microgram/kg. On day 10, the highest level of released phthalates (54.5 mg/kg) was measured in distilled water, followed by 44.4 mg/kg in 3% acetic acid and 32.3 mg/kg in 10% ethyl alcohol. According to plastic product categories, the highest pooled level of phthalates released to all three solutions was recorded for plastic toys (66.2 mg/kg), followed by food containers (37.6 mg/kg) and other consumer goods (27.4 mg/kg). According to plastic product categories, toys showed the most rapid phthalate release, with 65.4% (43.3 of 66.2 mg/kg) of the pooled level of phthalates released to all three solutions recorded on day 1. As indicated by the study results, the levels of phthalates released would not present a hazard for human health, not even over a prolonged period of time. However, data on the highest and fastest pooled phthalate release from plastic toys, and this especially to distilled water simulating salivary action, point to the need of continuous evaluation and amendments of the legislation on phthalates in consumer goods.