is the primary cause of onion center rot. Genetic data suggest that a phosphonic acid natural product is required for pathogenesis; however, the nature of the molecule is unknown. Here, we show that
...produces at least three phosphonates, two of which were purified and structurally characterized. The first, designated pantaphos, was shown to be 2-(hydroxyphosphonomethyl)maleate; the second, a probable biosynthetic precursor, was shown to be 2-(phosphonomethyl)maleate. Purified pantaphos is both necessary and sufficient for the hallmark lesions of onion center rot. Moreover, when tested against mustard seedlings, the phytotoxic activity of pantaphos was comparable to the widely used herbicides glyphosate and phosphinothricin. Pantaphos was also active against a variety of human cell lines but was significantly more toxic to glioblastoma cells. Pantaphos showed little activity when tested against a variety of bacteria and fungi.
is a significant plant pathogen that targets a number of important crops, a problem that is compounded by the absence of effective treatments to prevent its spread. Our identification of pantaphos as the key virulence factor in onion center rot suggests a variety of approaches that could be employed to address this significant plant disease. Moreover, the general phytotoxicity of the molecule suggests that it could be developed into an effective herbicide to counter the alarming rise in herbicide-resistant weeds.
Abstract
The concept of adaptive capacity has received significant attention within social-ecological and environmental change research. Within both the resilience and vulnerability literatures ...specifically, adaptive capacity has emerged as a fundamental concept for assessing the ability of social-ecological systems to adapt to environmental change. Although methods and indicators used to evaluate adaptive capacity are broad, the focus of existing scholarship has predominately been at the individual- and household- levels. However, the capacities necessary for humans to adapt to global environmental change are often a function of individual and societal characteristics, as well as cumulative and emergent capacities across communities and jurisdictions. In this paper, we apply a systematic literature review and co-citation analysis to investigate empirical research on adaptive capacity that focus on societal levels beyond the household. Our review demonstrates that assessments of adaptive capacity at higher societal levels are increasing in frequency, yet vary widely in approach, framing, and results; analyses focus on adaptive capacity at many different levels (e.g. community, municipality, global region), geographic locations, and cover multiple types of disturbances and their impacts across sectors. We also found that there are considerable challenges with regard to the ‘fit’ between data collected and analytical methods used in adequately capturing the cross-scale and cross-level determinants of adaptive capacity. Current approaches to assessing adaptive capacity at societal levels beyond the household tend to simply aggregate individual- or household-level data, which we argue oversimplifies and ignores the inherent interactions within and across societal levels of decision-making that shape the capacity of humans to adapt to environmental change across multiple scales. In order for future adaptive capacity research to be more practice-oriented and effectively guide policy, there is a need to develop indicators and assessments that are matched with the levels of potential policy applications.
Controlling invasive species presents a public‐good dilemma. Although environmental, social, and economic benefits of control accrue to society, costs are borne by only a few individuals and ...organizations. For decades, policy makers have used incentives and sanctions to encourage or coerce individual actors to contribute to the public good, with limited success. Diverse, subnational efforts to collectively manage invasive plants, insects, and animals provide effective alternatives to traditional command‐and‐control approaches. Despite this work, there has been little systematic evaluation of collective efforts to determine whether there are consistent principles underpinning success. We reviewed 32 studies to identify the extent to which collective‐action theories from related agricultural and environmental fields explain collaborative invasive species management approaches; describe and differentiate emergent invasive species collective‐action efforts; and provide guidance on how to enable more collaborative approaches to invasive species management. We identified 4 types of collective action aimed at invasive species—externally led, community led, comanaged, and organizational coalitions—that provide blueprints for future invasive species management. Existing collective‐action theories could explain the importance attributed to developing shared knowledge of the social‐ecological system and the need for social capital. Yet, collection action on invasive species requires different types of monitoring, sanctions, and boundary definitions. We argue that future government policies can benefit from establishing flexible boundaries that encourage social learning and enable colocated individuals and organizations to identify common goals, pool resources, and coordinate efforts.
Oportunidades para un Mejor Uso de la Teoría de Acción Colectiva en la Investigación y el Control del Manejo de Especies Invasoras
Resumen
El control de especies invasoras es un dilema para el bien público. Aunque los beneficios ambientales, sociales y económicos del control se acoplan a la sociedad, los costos los resuelven unos cuantos individuos y organizaciones. Durante décadas, los legisladores han utilizado incentivos y sanciones para alentar y forzar a los actores individuales a contribuir con el bien público, aunque con un éxito limitado. Los diversos esfuerzos sub‐nacionales para manejar colectivamente plantas, insectos y otros animales proporcionan alternativas efectivas a las estratégicas tradicionales de comando y control. A pesar de esta labor, ha habido una evaluación sistemática mínima de los esfuerzos colectivos para determinar si hay principios congruentes que estén respaldando el éxito. Revisamos 32 estudios para identificar la extensión a la cual las teorías de acción colectiva a partir de los campos agrícolas y ambientales relacionados explican las estrategias colaborativas de manejo de especies invasoras; describen y diferencian los esfuerzos de acción colectiva para especies invasoras emergentes; y proporcionan una guía sobre cómo posibilitar estrategias más colaborativas para el manejo de especies invasoras. Identificamos cuatro tipos de acción colectiva enfocada en las especies invasoras – guiada externamente, guiada por la comunidad, co‐manejada, y coaliciones organizacionales – que proporcionan los planos para el manejo futuro de especies invasoras. Las teorías existentes de acción colectiva podrían explicar la importancia que se le atribuye al conocimiento compartido en desarrollo sobre los sistemas socio‐ecológicos y la necesidad de capital social. Aun así, la acción colectiva sobre las especies invasoras requiere de diferentes tipos de monitoreo, sanciones y definición de los límites. Argumentamos que las próximas políticas gubernamentales pueden beneficiarse del establecimiento de límites flexibles que alientan el aprendizaje social y permiten que individuos y organizaciones colocadas identifiquen objetivos en común, acumulen y compartan recursos y coordinen esfuerzos.
摘要
入侵物种的控制是公共利益面临的一个困境。虽然入侵物种控制给环境、社会和经济带来的收益由社会共享, 但支出却只由少数个人和组织承担。几十年来, 决策者用激励和制裁的方式鼓励或迫使个人为公共利益做出贡献, 但成效有限。有许多地方性的工作致力于共同管理入侵植物、昆虫和动物, 为传统的指挥控制型方法提供了有效替代。尽管这样的工作已经展开, 然而却很少有对这些集体努力的系统评估, 来确定是否有统一的原则奠定成功的基础。我们综述了 32 项研究以确定相关农业和环境领域中的集体行动理论在多大程度上可以解释入侵物种的协作管理方法, 描述和区分新出现的入侵物种管理的集体行动, 并对如何促进合作来管理入侵物种提供了指导。我们划分了四类针对入侵物种的集体行动, 分别是外部领导、社区领导、共同管理和组织联盟, 这为未来的入侵物种管理提供了蓝图。现有的集体行动理论可以解释发展社会生态系统共识的重要性及对社会资本的需求。然而, 对入侵物种采取的集体行动需要不同类型的监督、制裁和范围界定。我们认为未来的政府政策可以受益于建立灵活的范围来促进社会学习, 帮助位于同一个地区的个人和组织确定共同目标、汇集资源并协调努力。【翻译: 胡怡思; 审校: 聂永刚】
Article impact statement: Invasive species control requires collective actions that prioritize flexible boundaries and social learning over monitoring and sanctions.
Wildlife conservation depends on supportive social as well as biophysical conditions. Social identities such as hunter and nonhunter are often associated with different attitudes toward wildlife. ...However, it is unknown whether dynamics within and among these identity groups explain how attitudes form and why they differ. To investigate how social identities help shape wildlife-related attitudes and the implications for wildlife policy and conservation, we built a structural equation model with survey data from Montana (USA) residents (n = 1758) that tested how social identities affect the relationship between experiences with grizzly bears (Ursus arctos horribilis) and attitudes toward the species. Model results (r
= 0.51) demonstrated that the hunter identity magnified the negative effect of vicarious property damage on attitudes toward grizzly bears (β = -0.381, 95% confidence interval CI: -0.584 to -0.178, p < 0.001), which in turn strongly influenced acceptance (β = -0.571, 95% CI: -0.611 to -0.531, p < 0.001). Our findings suggested that hunters' attitudes toward grizzly bears likely become more negative primarily because of in-group social interactions about negative experiences, and similar group dynamics may lead nonhunters to disregard the negative experiences that out-group members have with grizzly bears. Given the profound influence of social identity on human cognitions and behaviors in myriad contexts, the patterns we observed are likely important in a variety of wildlife conservation situations. To foster positive conservation outcomes and minimize polarization, management strategies should account for these identity-driven perceptions while prioritizing conflict prevention and promoting positive wildlife narratives within and among identity groups. This study illustrates the utility of social identity theory for explaining and influencing human-wildlife interactions.
Pantaphos is small molecule virulence factor made by the plant pathogen Pantoea ananatis. An 11 gene operon, designated hvr for high virulence, is required for production of this phosphonic acid ...natural product, but the metabolic steps used in its production have yet to be established. Herein, we determine the complete biosynthetic pathway using a combination of bioinformatics, in vitro biochemistry and in vivo heterologous expression. Only 6 of the 11 hvr genes are needed to produce pantaphos, while a seventh is likely to be required for export. Surprisingly, the pathway involves a series of O‐methylated intermediates, which are then hydrolyzed to produce the final product. The methylated intermediates are produced by an irreversible S‐adenosylmethione (SAM)‐dependent methyltransferase that is required to drive a thermodynamically unfavorable dehydration in the preceding step, a function not previously attributed to members of this enzyme class. Methylation of pantaphos by the same enzyme is also likely to limit its toxicity in the producing organism. The pathway also involves a novel flavin‐dependent monooxygenase that differs from homologous proteins due to its endogenous flavin‐reductase activity. Heterologous production of pantaphos by Escherichia coli strains expressing the minimal gene set strongly supports the in vitro biochemical data.
Biosynthesis of the phosphonate natural product pantaphos involves a SAM‐dependent methylation reaction, despite the fact that no SAM‐derived carbon atoms are present in the final product. This irreversible reaction provides the driving force needed to overcome the unfavorable thermodynamics of the preceding dehydration, while reducing the toxicity of the biosynthetic intermediates.
Over the last decade, there has been a remarkable increase in scientific literature addressing human–wildlife interactions (HWI) and associated concepts, such as coexistence, tolerance, and ...acceptance. Despite increased attention, these terms are rarely defined or consistently applied across publications. Indeed, the meaning of these concepts, especially coexistence, is frequently assumed and left for the reader to interpret, making it hard to compare studies, test metrics, and build upon previous HWI research. To work toward a better understanding of these terms, we conducted two World Café sessions at international conferences in Namibia, Africa and Ontario, Canada. Here, we present the array of perspectives revealed in the workshops and build upon these results to describe the meaning of coexistence as currently applied by conservation scientists and practitioners. Although we focus on coexistence, it is imperative to understand the term in relation to tolerance and acceptance, as in many cases these latter terms are used to express, measure, or define coexistence. Drawing on these findings, we discuss whether a common definition of these terms is possible and how the conservation field might move toward clarifying and operationalizing the concept of human-wildlife coexistence.
Coexistence between large carnivores and humans is a global conservation concern. Montana (USA) is home to recovering grizzly bear (Ursus arctos) populations and increasing human–grizzly ...interactions. In 2019, we administered a survey of Montanans to investigate factors influencing normative beliefs about grizzly bear population sizes and quantify the relationship between these beliefs and satisfaction with grizzly management in the state. Using a linear regression (r2 = .61), we found that residents with positive attitudes and emotional dispositions toward grizzlies or who trusted the agency were more likely to believe grizzly populations were too low. Residents who believed hunting should be used to manage conflict, were themselves hunters, had vicarious wildlife experience with property damage, believed grizzly populations were expanding, or were older were more likely to believe populations were too high. We found a negative quadratic relationship between normative grizzly bear population size beliefs and satisfaction with management, suggesting an optimal “Goldilocks” zone where coexistence is most possible. In practice, if observed Goldilocks zones are incompatible with population numbers required to meet conservation goals, considering factors influencing these beliefs may help bolster acceptance of larger population sizes.
Research within psychology and other disciplines has shown that exposure to natural environments holds extensive physiological and psychological benefits. Adding to the health and cognitive benefits ...of natural environments, evidence suggests that exposure to nature also promotes healthy human decision-making. Unhealthy decision-making (e.g., smoking, non-medical prescription opioid misuse) and disorders associated with lack of impulse control e.g., tobacco use, opioid use disorder (OUD), contribute to millions of preventable deaths annually (i.e., 6 million people die each year of tobacco-related illness worldwide, deaths from opioids from 2002 to 2017 have more than quadrupled in the United States alone). Impulsive and unhealthy decision-making also contributes to many pressing environmental issues such as climate change. We recently demonstrated a causal link between visual exposure to nature (e.g., forests) and improved self-control (i.e., decreased impulsivity) in a laboratory setting, as well as the extent to which nearby nature and green space exposure improves self-control and health decisions in daily life outside of the experimental laboratory. Determining the benefits of nearby nature for self-controlled decision-making holds theoretical and applied implications for the design of our surrounding environments. In this article, we synergize the overarching results of recent research endeavors in three domains including the effects of nature exposure on (1) general health-related decision-making, (2) health and decision-making relevant for application to addiction related processes (e.g., OUD), and (3) environmentally relevant decision-making. We also discuss key future directions and conclusions.
Invasive terrestrial plants globally threaten agricultural and natural systems. Prolific dispersal mechanisms enable "weeds" to colonize across ownership boundaries, constituting a collective action ...problem where effective control requires contributions from multiple actors. Researchers have long recognized the cross-boundary nature of weed control, yet most studies have focused on whether actor-specific characteristics, such as sociodemographics and cognition, influenced individual weed control behaviors. More recent work has begun to explore the drivers of communal control efforts, i.e., cooperatives, group actions. Few studies have empirically investigated how the collective aspects of weed invasions influence individual control behaviors. Here we provide quantitative evidence of a relationship between collective aspects of the weed control problem and landowners' willingness to engage in individual weed control efforts. In a mail-back survey of Montana landowners (n = 1327) we found collective factors, such as injunctive norms and the belief that weeds are a cross-boundary problem, were significantly correlated with willingness to engage in three different weed control behaviors. Each behavior was correlated with a unique suite of collective factors suggesting that successful interventions must be behavior-specific. These results add to a growing body of evidence that the collective nature of invasive species control is critical for understanding human behavioral responses.
Resilience has become a common goal for science-based natural resource management, particularly in the context of changing climate and disturbance regimes. Integrating varying perspectives and ...definitions of resilience is a complex and often unrecognized challenge to applying resilience concepts to social–ecological systems (SESs) management. Using wildfire as an example, we develop a framework to expose and separate two important dimensions of resilience: the inherent properties that maintain structure, function, or states of an SES and the human perceptions of desirable or valued components of an SES. In doing so, the framework distinguishes between value-free and human-derived, value-explicit dimensions of resilience. Four archetypal scenarios highlight that ecological resilience and human values do not always align and that recognizing and anticipating potential misalignment is critical for developing effective management goals. Our framework clarifies existing resilience theory, connects literature across disciplines, and facilitates use of the resilience concept in research and land-management applications.
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