ALBERT

Description: Article PP2A-B56 regulates the stability of kinetochore-microtubule attachments by dephosphorylating several kinetochore proteins. Porter et al . identify Bod1 as a specific inhibitor of PP2A-B56 phosphatase activity and show that this activity is required for proper chromosome alignment during mitosis. Nature Communications doi: 10.1038/ncomms3677 Authors: Iain M. Porter, Katharina Schleicher, Michael Porter, Jason R. Swedlow

Description: Because of global land surface warming, extreme temperature events are expected to occur more often and more intensely, affecting the growth and development of the major cereal crops in several ways, thus affecting the production component of food security. In this paper, we have identified rice and maize crop responses to temperature in different, but consistent, phenological phases and development stages. A literature review and data compilation of around 140 scientific articles have determined the key temperature thresholds and response to extreme temperature effects for rice and maize, complementing an earlier study on wheat. Lethal temperatures and cardinal temperatures, together with error estimates, have been identified for phenological phases and development stages. Following the methodology of previous work, we have collected and statistically analysed temperature thresholds of the three crops for the key physiological processes such as leaf initiation, shoot growth and root growth and for the most susceptible phenological phases such as sowing to emergence, anthesis and grain filling. Our summary shows that cardinal temperatures are conservative between studies and are seemingly well-defined in all three crops. Anthesis and ripening are the most sensitive temperature stages in rice as well as in wheat and maize. We call for further experimental studies of the effects of transgressing threshold temperatures so such responses can be included into crop impact and adaptation models. This article is protected by copyright. All rights reserved.

Description: Since 1990, the IPCC has produced five Assessment Reports (ARs) including agriculture. Using a database of the ca. 2,100 cited experiments and simulations in the five ARs, our conclusions are that crop yields decline but with large statistical variation. Livestock effects have almost been quantitatively absent. Mitigation assessments need better to link emissions and their mitigation with food production and security; agriculture has been dealt with inconsistently between the IPCC five ARs. IPCC needs to examine interactions between crop resource use efficiencies and include production and nonproduction aspects of food security. Abstract Since 1990, the Intergovernmental Panel on Climate Change (IPCC) has produced five Assessment Reports (ARs), in which agriculture as the production of food for humans via crops and livestock have featured in one form or another. A constructed database of the ca. 2,100 cited experiments and simulations in the five ARs was analyzed with respect to impacts on yields via crop type, region, and whether adaptation was included. Quantitative data on impacts and adaptation in livestock farming have been extremely scarce in the ARs. The main conclusions from impact and adaptation are that crop yields will decline, but that responses have large statistical variation. Mitigation assessments in the ARs have used both bottom‐up and top‐down methods but need better to link emissions and their mitigation with food production and security. Relevant policy options have become broader in later ARs and included more of the social and nonproduction aspects of food security. Our overall conclusion is that agriculture and food security, which are two of the most central, critical, and imminent issues in climate change, have been dealt with an unfocussed and inconsistent manner between the IPCC five ARs. This is partly a result of not only agriculture spanning two IPCC working groups but also the very strong focus on projections from computer crop simulation modeling. For the future, we suggest a need to examine interactions between themes such as crop resource use efficiencies and to include all production and nonproduction aspects of food security in future roles for integrated assessment models.

Description: The projected impact of 1.5 and 2.0°C warming above the pre‐industrial period on wheat production varies spatially; a larger increase is projected for temperate high rainfall regions than for moderate hot low rainfall and irrigated regions. Grain yields in warmer regions are more likely to be reduced than in cooler regions. Despite mostly positive impacts on global average grain yields, the frequency of extremely low yields and yield inter‐annual variability will increase under both warming scenarios for some of the hot growing locations, including locations from the second largest global wheat producer—India, which supplies more than 14% of global wheat. The projected global impacts of warming of 〈2°C on wheat production is therefore not evenly distributed and will affect regional food security across the globe as well as food prices and trade. Abstract Efforts to limit global warming to below 2°C in relation to the pre‐industrial level are under way, in accordance with the 2015 Paris Agreement. However, most impact research on agriculture to date has focused on impacts of warming 〉2°C on mean crop yields, and many previous studies did not focus sufficiently on extreme events and yield interannual variability. Here, with the latest climate scenarios from the Half a degree Additional warming, Prognosis and Projected Impacts (HAPPI) project, we evaluated the impacts of the 2015 Paris Agreement range of global warming (1.5 and 2.0°C warming above the pre‐industrial period) on global wheat production and local yield variability. A multi‐crop and multi‐climate model ensemble over a global network of sites developed by the Agricultural Model Intercomparison and Improvement Project (AgMIP) for Wheat was used to represent major rainfed and irrigated wheat cropping systems. Results show that projected global wheat production will change by −2.3% to 7.0% under the 1.5°C scenario and −2.4% to 10.5% under the 2.0°C scenario, compared to a baseline of 1980–2010, when considering changes in local temperature, rainfall, and global atmospheric CO2 concentration, but no changes in management or wheat cultivars. The projected impact on wheat production varies spatially; a larger increase is projected for temperate high rainfall regions than for moderate hot low rainfall and irrigated regions. Grain yields in warmer regions are more likely to be reduced than in cooler regions. Despite mostly positive impacts on global average grain yields, the frequency of extremely low yields (bottom 5 percentile of baseline distribution) and yield inter‐annual variability will increase under both warming scenarios for some of the hot growing locations, including locations from the second largest global wheat producer—India, which supplies more than 14% of global wheat. The projected global impact of warming 〈2°C on wheat production is therefore not evenly distributed and will affect regional food security across the globe as well as food prices and trade.

Description: Article Centrosome separation, promoted by the kinesin Eg5, is antagonized by the guanine nucleotide exchange factor Tiam1 through an unknown mechanism. Here Whalley et al . show that Tiam1 is phosphorylated by cyclin-dependent kinase 1 in prophase, leading to downstream activation of p21-activated kinases (PAKs). Nature Communications doi: 10.1038/ncomms8437 Authors: Helen J. Whalley, Andrew P. Porter, Zoi Diamantopoulou, Gavin R. M. White, Eduardo Castañeda-Saucedo, Angeliki Malliri

Description: Article G-quadruplexes formed by four guanine bases in a square planar arrangement in telomeres may prevent extension of this region by telomerase. Here, the authors show that telomerase can localize to and partially unwind and extend G-quadruplexes, suggesting an important biological role for G-quadruplexes. Nature Communications doi: 10.1038/ncomms8643 Authors: Aaron L. Moye, Karina C. Porter, Scott B. Cohen, Tram Phan, Katherine G. Zyner, Natsuki Sasaki, George O. Lovrecz, Jennifer L. Beck, Tracy M. Bryan

Description: How climate constrains species’ distributions through time and space is an important question in the context of conservation planning for climate change. Despite increasing awareness of the need to incorporate mechanism into species distribution models (SDMs), mechanistic modelling of endotherm distributions remains limited in the current literature. Using the American pika ( Ochotona princeps ) as an example, we present a framework whereby mechanism can be incorporated into endotherm SDMs. Pika distribution has repeatedly been found to be constrained by warm temperatures, so we used Niche Mapper, a mechanistic heat-balance model, to convert macroclimate data to pika-specific surface-activity time in summer across the western United States. We then explored the difference between using a macroclimate predictor (summer temperature) and using a mechanistic predictor (predicted surface-activity time) in SDMs. Both approaches accurately predicted pika presences in current and past climate regimes. However, the activity models predicted 8-19% less habitat loss in response to annual temperature increases of ~3-5°C predicted in the region by 2070, suggesting that pikas may be able to buffer some climate-change effects through behavioral thermoregulation that can be captured by mechanistic modeling. Incorporating mechanism added value to the modeling by providing increased confidence in areas where different modeling approaches agreed and providing a range of outcomes in areas of disagreement. It also provided a more proximate variable relating animal distribution to climate, allowing investigations into how unique habitat characteristics and intraspecific phenotypic variation may allow pikas to exist in areas outside those predicted by generic SDMs. Only a small number of easily obtainable data are required to parameterize this mechanistic model for any endotherm, and its use can improve SDM predictions by explicitly modeling a widely applicable direct physiological effect: climate-imposed restrictions on activity. This more complete understanding is necessary to inform climate-adaptation actions, management strategies, and conservation plans. This article is protected by copyright. All rights reserved.

Description: Agriculture satisfies the basic need of society to produce food but must do so without undermining the world's capacity to sustain future food production and ecosystem services (Foley et al ., 2011; Rockström et al ., 2009; Foley et al ., 2005). Operating on a planet with finite resources and boundaries, agriculture must operate within three limits (Beddington et al ., 2012); 1) the quantity of food supply that can be produced under a given climate, 2) the quantity of food demanded by a growing and economically changing population, and 3) the impact of food production on the environment. Currently, agriculture and land-use change (LUC) are responsible for ~1/4 of total greenhouse gas (GHG) emissions from human activities (Smith et al ., 2014). As the human population grows, and is projected to move toward a more animal-based diet, it is projected that crop- and livestock production need to increase by 48% and 80% by 2050, respectively (FAO, 2006). It has been suggested that this could elevate agricultural non-CO 2 emissions 76% by 2050 relative to 1995 (Popp et al ., 2010). Yet agriculture has large potentials for mitigating climate change, even at relatively low cost (Smith et al ., 2014; Smith et al ., 2008; Nabuurs et al ., 2007; Schneider & Smith, 2009). This article is protected by copyright. All rights reserved.