Competitiveness describes a key ability important for plants to grow and survive abiotic and biotic stresses. Under optimal, but particularly under non-optimal conditions, plants compete for resources including nutrients, light, water, space, pollinators and other. Competition occurs above- and belowground. In resource-poor habitats, competition is generally considered to be more pronounced than in resource-rich habitats. Although competition occurs between different players within an ecosystem such as between plants and soil microorganisms, our topic focusses on plant-plant interactions and includes inter-specific competition between different species of similar and different life forms and intra-specific competition. Strategies for securing resources via spatial or temporal separation and different resource needs generally reduce competition. Increasingly important is the effect of invasive plants and subsequent decline in biodiversity and ecosystem function. Current knowledge and future climate predictions suggest that in some situations competition will be intensified with occurrence of increased abiotic (e.g. water and nutrient limitations) and biotic stresses (e.g. mass outbreak of insects), but competition might also decrease in situations where plant productivity and survival declines (e.g. habitats with degraded soils). Changing interactions, climate change and biological invasions place new challenges on ecosystems. Understanding processes and mechanisms that underlie the interactions between plants and environmental factors will aid predictions and intervention. There is much need to develop strategies to secure ecosystem services via primary productivity and to prevent the continued loss of biodiversity. This Research Topic provides an up-to-date account of knowledge on plant-plant interactions with a focus on identifying the mechanisms underpinning competitive ability. The Research Topic aims to showcase knowledge that links ecological relevance with physiological processes to better understanding plant and ecosystem function.

Growing plants have a constitutive demand for sulfur to synthesize proteins, sulfolipids and other essential sulfur containing molecules for growth and development. The uptake and subsequent distribution of sulfate is regulated in response to demand and environmental cues. The importance of sulfate for plant growth and vigor and hence crop yield and nutritional quality for human and animal diets has been clearly recognized. The acquisition of sulfur by plants, however, has become an increasingly important concern for the agriculture due to the decreasing S-emissions from industrial sources and the consequent limitation of inputs from atmospheric deposition. Molecular characterization involving transcriptomics, proteomics and metabolomics in Arabidopsis thaliana as well as in major crops revealed that sulfate uptake, distribution and assimilation are finely regulated depending on sulfur status and demand, and that these regulatory networks are integrated with cell cycle, photosynthesis, carbohydrate metabolism, hormonal signaling, uptake and assimilation of other nutrients, etc., to enable plant growth, development, and reproduction even under different biotic and abiotic stresses. This knowledge can be used to underpin approaches to enhance plant growth and nutritional quality of major food crops around the world. Although considerable progress has been made regarding the central role of sulfur metabolism in plant growth, development and stress response, several frontiers need to be explored to reveal the mechanisms of the cross-talk between sulfur metabolism and these processes. In this research topic the knowledge on plant sulfur metabolism is reviewed and updated. Focus is put not only on molecular mechanisms of control of sulfur metabolism but also on its integration with other vital metabolic events. The topic covers 4 major areas of sulfur research: sulfate uptake, assimilation and metabolism, regulation, and role in stress response. We hope that the topic will promote interaction between researchers with different expertise and thus contribute to a more integrative approach to study sulfur metabolism in plants.

Plant diseases are destructive and threaten virtually any crop grown on a commercial scale. They are kept in check by plant breeding strategies that have introgressed disease resistance genes into many important crops, and by the deployment of costly control measures, such as antibiotics and fungicides. However, the capacity for the agents of plant disease - viruses, bacteria, fungi, and oomycetes - to adapt to new conditions, overcoming disease resistance and becoming resistant to pesticides, is very great. For these reasons, understanding the biology of plant diseases is essential for the development of durable control strategies. Plant-Pathogen Interactions provides and overview of our current knowledge of plant-pathogen interactions and the establishment of plant disease, drawing together fundamental new information on plant infection mechanisms and host responses. The role of molecular signals, gene regulation, and the physiology of pathogenic organisms are emphasized, but the role of the prevailing environment in the conditioning of disease is also discussed. Emphasizing the broader understanding that has emerged from the use of molecular genetics and genomics, Plant-Pathogen Interactions highlights those interactions that have been most widely studied and those in which genome information has provided a new level of understanding.

The classic case for why government must support science—with a new essay by physicist and former congressman Rush Holt on what democracy needs from science today Science, the Endless Frontier is recognized as the landmark argument for the essential role of science in society and government’s responsibility to support scientific endeavors. First issued when Vannevar Bush was the director of the US Office of Scientific Research and Development during the Second World War, this classic remains vital in making the case that scientific progress is necessary to a nation’s health, security, and prosperity. Bush’s vision set the course for US science policy for more than half a century, building the world’s most productive scientific enterprise. Today, amid a changing funding landscape and challenges to science’s very credibility, Science, the Endless Frontier resonates as a powerful reminder that scientific progress and public well-being alike depend on the successful symbiosis between science and government. This timely new edition presents this iconic text alongside a new companion essay from scientist and former congressman Rush Holt, who offers a brief introduction and consideration of what society needs most from science now. Reflecting on the report’s legacy and relevance along with its limitations, Holt contends that the public’s ability to cope with today’s issues—such as public health, the changing climate and environment, and challenging technologies in modern society—requires a more capacious understanding of what science can contribute. Holt considers how scientists should think of their obligation to society and what the public should demand from science, and he calls for a renewed understanding of science’s value for democracy and society at large. A touchstone for concerned citizens, scientists, and policymakers, Science, the Endless Frontier endures as a passionate articulation of the power and potential of science.

Programmed cell death (PCD) is a genetically encoded, active process which results in the death of individual cells, tissues, or whole organs. PCD plays an essential role in plant development and defense, and occurs throughout a plant’s lifecycle from the death of the embryonic suspensor to leaf and floral organ senescence. In plant biology, PCD is a relatively new research area, however, as its fundamental importance is further recognized, publications in the area are beginning to increase significantly. The field currently has few foundational reference books and there is a critical need for books that summarizes recent findings in this important area. This book contains chapters written by several of the world’s leading researchers in PCD. This book will be invaluable for PhD or graduate students, or for scientists and researchers entering the field. Established researchers will also find this timely work useful as an up-to-date overview of this fascinating research area.