SciCombinator

Discover the most talked about and latest scientific content & concepts.

Journal: Nature plants

165

Beer is the most popular alcoholic beverage in the world by volume consumed, and yields of its main ingredient, barley, decline sharply in periods of extreme drought and heat. Although the frequency and severity of drought and heat extremes increase substantially in range of future climate scenarios by five Earth System Models, the vulnerability of beer supply to such extremes has never been assessed. We couple a process-based crop model (decision support system for agrotechnology transfer) and a global economic model (Global Trade Analysis Project model) to evaluate the effects of concurrent drought and heat extremes projected under a range of future climate scenarios. We find that these extreme events may cause substantial decreases in barley yields worldwide. Average yield losses range from 3% to 17% depending on the severity of the conditions. Decreases in the global supply of barley lead to proportionally larger decreases in barley used to make beer and ultimately result in dramatic regional decreases in beer consumption (for example, -32% in Argentina) and increases in beer prices (for example, +193% in Ireland). Although not the most concerning impact of future climate change, climate-related weather extremes may threaten the availability and economic accessibility of beer.

101

The African baobab is the biggest and longest-living angiosperm tree. By using radiocarbon dating we identified the stable architectures that enable baobabs to reach large sizes and great ages. We report that 9 of the 13 oldest and 5 of the 6 largest individuals have died, or at least their oldest parts/stems have collapsed and died, over the past 12 years; the cause of the mortalities is still unclear.

52

Genome editing holds great promise for increasing crop productivity, and there is particular interest in advancing breeding in orphan crops, which are often burdened by undesirable characteristics resembling wild relatives. We developed genomic resources and efficient transformation in the orphan Solanaceae crop ‘groundcherry’ (Physalis pruinosa) and used clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein-9 nuclease (Cas9) (CRISPR-Cas9) to mutate orthologues of tomato domestication and improvement genes that control plant architecture, flower production and fruit size, thereby improving these major productivity traits. Thus, translating knowledge from model crops enables rapid creation of targeted allelic diversity and novel breeding germplasm in distantly related orphan crops.

40

Light-sheet fluorescence microscopy (LSFM) methods collectively represent the major breakthrough in developmental bio-imaging of living multicellular organisms. They are becoming a mainstream approach through the development of both commercial and custom-made LSFM platforms that are adjusted to diverse biological applications. Based on high-speed acquisition rates under conditions of low light exposure and minimal photo-damage of the biological sample, these methods provide ideal means for long-term and in-depth data acquisition during organ imaging at single-cell resolution. The introduction of LSFM methods into biology extended our understanding of pattern formation and developmental progress of multicellular organisms from embryogenesis to adult body. Moreover, LSFM imaging allowed the dynamic visualization of biological processes under almost natural conditions. Here, we review the most important, recent biological applications of LSFM methods in developmental studies of established and emerging plant model species, together with up-to-date methods of data editing and evaluation for modelling of complex biological processes. Recent applications in animal models push LSFM into the forefront of current bio-imaging approaches. Since LSFM is now the single most effective method for fast imaging of multicellular organisms, allowing quantitative analyses of their long-term development, its broader use in plant developmental biology will likely bring new insights.

40

Achieving sustainable crop production while feeding an increasing world population is one of the most ambitious challenges of this century(1). Meeting this challenge will necessarily imply a drastic reduction of adverse environmental effects arising from agricultural activities(2). The reduction of pesticide use is one of the critical drivers to preserve the environment and human health. Pesticide use could be reduced through the adoption of new production strategies(3-5); however, whether substantial reductions of pesticide use are possible without impacting crop productivity and profitability is debatable(6-17). Here, we demonstrated that low pesticide use rarely decreases productivity and profitability in arable farms. We analysed the potential conflicts between pesticide use and productivity or profitability with data from 946 non-organic arable commercial farms showing contrasting levels of pesticide use and covering a wide range of production situations in France. We failed to detect any conflict between low pesticide use and both high productivity and high profitability in 77% of the farms. We estimated that total pesticide use could be reduced by 42% without any negative effects on both productivity and profitability in 59% of farms from our national network. This corresponded to an average reduction of 37, 47 and 60% of herbicide, fungicide and insecticide use, respectively. The potential for reducing pesticide use appeared higher in farms with currently high pesticide use than in farms with low pesticide use. Our results demonstrate that pesticide reduction is already accessible to farmers in most production situations. This would imply profound changes in market organization and trade balance.

Concepts: Agriculture, Redox, Insecticide

37

The growing human population and a changing environment have raised significant concern for global food security, with the current improvement rate of several important crops inadequate to meet future demand 1 . This slow improvement rate is attributed partly to the long generation times of crop plants. Here, we present a method called ‘speed breeding’, which greatly shortens generation time and accelerates breeding and research programmes. Speed breeding can be used to achieve up to 6 generations per year for spring wheat (Triticum aestivum), durum wheat (T. durum), barley (Hordeum vulgare), chickpea (Cicer arietinum) and pea (Pisum sativum), and 4 generations for canola (Brassica napus), instead of 2-3 under normal glasshouse conditions. We demonstrate that speed breeding in fully enclosed, controlled-environment growth chambers can accelerate plant development for research purposes, including phenotyping of adult plant traits, mutant studies and transformation. The use of supplemental lighting in a glasshouse environment allows rapid generation cycling through single seed descent (SSD) and potential for adaptation to larger-scale crop improvement programs. Cost saving through light-emitting diode (LED) supplemental lighting is also outlined. We envisage great potential for integrating speed breeding with other modern crop breeding technologies, including high-throughput genotyping, genome editing and genomic selection, accelerating the rate of crop improvement.

Concepts: Wheat, Light-emitting diode, Acceleration, Food security, Bread, Durum, Faboideae, Triticeae

35

The Eurasian grapevine (Vitis vinifera) has long been important for wine production as well as being a food source. Despite being clonally propagated, modern cultivars exhibit great morphological and genetic diversity, with thousands of varieties described in historic and contemporaneous records. Through historical accounts, some varieties can be traced to the Middle Ages, but the genetic relationships between ancient and modern vines remain unknown. We present target-enriched genome-wide sequencing data from 28 archaeological grape seeds dating to the Iron Age, Roman era and medieval period. When compared with domesticated and wild accessions, we found that the archaeological samples were closely related to western European cultivars used for winemaking today. We identified seeds with identical genetic signatures present at different Roman sites, as well as seeds sharing parent-offspring relationships with varieties grown today. Furthermore, we discovered that one seed dated to ~1100 CE was a genetic match to ‘Savagnin Blanc’, providing evidence for 900 years of uninterrupted vegetative propagation.

35

Many epiphytic plants have associated with ants to gain nutrients. Here, we report a novel type of ant-plant symbiosis in Fiji where one ant species actively and exclusively plants the seeds and fertilizes the seedlings of six species of Squamellaria (Rubiaceae). Comparison with related facultative ant plants suggests that such farming plays a key role in mutualism stability by mitigating the critical re-establishment step.

Concepts: Plant, Symbiosis, Fern, Seed, Plant morphology, Ant, Mutualism, Epiphyte

32

Coffee farming provides livelihoods for around 15 million farmers in Ethiopia and generates a quarter of the country’s export earnings. Against a backdrop of rapidly increasing temperatures and decreasing rainfall, there is an urgent need to understand the influence of climate change on coffee production. Using a modelling approach in combination with remote sensing, supported by rigorous ground-truthing, we project changes in suitability for coffee farming under various climate change scenarios, specifically by assessing the exposure of coffee farming to future climatic shifts. We show that 39-59% of the current growing area could experience climatic changes that are large enough to render them unsuitable for coffee farming, in the absence of significant interventions or major influencing factors. Conversely, relocation of coffee areas, in combination with forest conservation or re-establishment, could see at least a fourfold (>400%) increase in suitable coffee farming area. We identify key coffee-growing areas that are susceptible to climate change, as well as those that are climatically resilient.

Concepts: Ethiopia, Precipitation, Climate, Weather, Coffee, Climate change, Solar variation, Thermohaline circulation

32

Food production and consumption cause approximately one-third of total greenhouse gas emissions(1-3), and therefore delivering food security challenges not only the capacity of our agricultural system, but also its environmental sustainability(4-7). Knowing where and at what level environmental impacts occur within particular food supply chains is necessary if farmers, agri-food industries and consumers are to share responsibility to mitigate these impacts(7,8). Here we present an analysis of a complete supply chain for a staple of the global diet, a loaf of bread. We obtained primary data for all the processes involved in the farming, production and transport systems that lead to the manufacture of a particular brand of 800 g loaf. The data were analysed using an advanced life cycle assessment (LCA) tool(9), yielding metrics of environmental impact, including greenhouse gas emissions. We show that more than half of the environmental impact of producing the loaf of bread arises directly from wheat cultivation, with the use of ammonium nitrate fertilizer alone accounting for around 40%. These findings reveal the dependency of bread production on the unsustainable use of fertilizer and illustrate the detail needed if the actors in the supply chain are to assume shared responsibility for achieving sustainable food production.

Concepts: Agriculture, Ammonia, Food, Nitrogen, Sustainability, Food security, Greenhouse gas, Ammonium nitrate