Microbial ecology of the invasive plant Kudzu (Pueraria montana var. lobata) in the Southeast United States: Toward a framework of integrative weed management

One unrealized aspect of invasive plant management is the incorporation of plant-microbe and microbe-microbe interactions, including utilization of microorganisms as biocontrol agents. While the development of such an ecological approach is in its infancy, I argue that incorporation of microbes into management plans should be a priority for the development of more sustainable tools for invasive plant control and incorporation into integrative pest management programs. Fungal endophytes, fungal species that live within a plant but do not negatively impact plant fitness or functions, are a major component of the plant microbiome. Kudzu (Pueraria montana var. lobata) is a dominant, abundant, and highly aggressive invasive plant in the Southeast United States, and it serves as a pathogen reservoir that impacts economically important leguminous crops. To better understand the tripartite interactions between kudzu, endophytes, and the environment toward the development of alternative control strategies, I investigated 1) the environmental drivers controlling kudzu fungal endophyte communities, which included the very first investigation into the kudzu microbiome, 2) the impacts of different established kudzu control options on soil physicochemical and biological properties, and 3) the endophyte-endophyte interactions in vitro of kudzu derived fungal endophytes and pathogens to elucidate potential antagonistic and/or facilitation dynamics. This work advances our understanding of the potential use of fungal endophytes as an effective ecologically based approach to manage invasive plants yet reflects a strong need for additional research into the impacts of endophytes on plant performance and fitness. This project provides needed background knowledge toward the development additional invasive control strategies

Interactions between fungal endophytes and pathogens isolated from the invasive plant kudzu (Pueraria montana var. lobata)

In this study, we examined the in vitro interactions between fungal endophytes and pathogens isolated from the invasive plant kudzu (Pueraria montana var. lobata) and test if endophytes might facilitate pathogen growth. This represents a required initial step towards the development of candidate fungal inocula that can aid in the suppression of kudzu. While most tested endophyte-pathogen assays suggest antagonism and/or competitive exclusion, we identified several pathogen/endophyte combinations that suggest pathogen facilitation. Additional work is needed to test if these may have in planta effects on phytopathogenicity. The present study accentuates on the potential of fungal endophytes as an effective ecological approach to manage invasive plants via pathogens facilitation

A path forward: Promoting microbial-based methods in the control of invasive plant species

In this review, we discuss the unrealized potential of incorporating plant–microbe and microbe–microbe interactions into invasive plant management strategies. While the development of this as a viable strategy is in its infancy, we argue that incorporation of microbial components into management plans should be a priority and has great potential for diversifying sustainable control options. We advocate for increased research into microbial-mediated phytochemical production, microbial controls to reduce the competitiveness of invasive plants, microbial-mediated increases of herbicidal tolerance of native plants, and to facilitate increased pathogenicity of plant pathogens of invasive plants

Drivers of foliar fungal endophytic communities of Kudzu (Pueraria montana var. lobata) in the Southeast United States

Fungal endophytes play important roles in plant fitness and plant-microbe interactions. Kudzu (Pueraria montana var. lobata) is a dominant, abundant, and highly aggressive invasive plant in the Southeast United States. Kudzu serves as a pathogen reservoir that impacts economically important leguminous crops. We conducted the first investigations on kudzu fungal endophytes (Illumina MiSeq-ITS2) to elucidate drivers of endophytic communities across the heart of the invasive range in the Southeast United States (TN, MS, AL, GA). We tested the impacts of multiple environmental parameters (Chlorophyll, NO3-, K+, soil pH, leaf area, host genotype, traffic intensity, and geographic location) on foliar endophyte communities. Endophytic communities were diverse and structured by many factors in our PerMANOVA analyses, but location, genotype, and traffic (proxy for pollution) were the strongest drivers of community composition (R2 = 0.152, p \u3c 0.001, R2 = 0.129, p \u3c 0.001, and R2 = 0.126, p \u3c 0.001, respectively). Further, we examined the putative ecological interactions between endophytic fungi and plant pathogens. We identify numerous OTUs that are positively and strongly associated with pathogen occurrence, largely within the families Montagnulaceae and Tremellales incertae sedis. Taken together, these data suggest location, host genetics and local pollution play instrumental roles in structuring communities, and integrative plant management must consider these factors when developing management strategies

Seasonal disconnects between saprobic and mycorrhizal sporocarp communities in the Southern Appalachian Mountains

The southern Appalachian Mountains in the United States are heavily forested with diverse forest types and vegetation structures and is generally considered a biodiversity hotspot. Fungal sporocarp investigations in this region are not new, but multi-year interseasonal investigations into sporocarp community patterns are rare. Using a 4-year (2014–2017) repeated monthly macrofungal sampling dataset (May–October) across an elevational gradient (associated with vegetation structure), we queried community, seasonal, and guild community ecological patterns. In doing so, we (1) demonstrate a temporal disconnect between saprobic and ectomycorrhizal taxa, (2) describe increased community variability across the growing season, and (3) explore individual taxa occurrences across seasons and examine co-occurrence patterns between taxa and guilds. Further, we explore congruence between sporocarp and metabarcoding fungal datasets and advocate the utility of both sampling schemes

Integration of Cognitive Skills as a Cross-Cutting Theme Into the Undergraduate Medical Curriculum at Tehran University of Medical Sciences

Nowadays, improvement of thinking skills of students is one of the universally supported aims in the majority of medical schools. This study aims to design longitudinal theme of reasoning, problem-solving and decision-making into the undergraduate medical curriculum at Tehran University of Medical Sciences (TUMS). A participatory approach was applied to design the curriculum during 2009-2011. The project was conducted by the contribution of representatives of both basic and clinical faculty members, students and graduates at Tehran University of Medical Sciences. The first step toward integrating cognitive skills into the curriculum was to assemble a taskforce of different faculty and students, including a wide variety of fields with multidisciplinary expertise using nonprobability sampling and the snowball method. Several meetings with the contribution of experts and some medical students were held to generate the draft of expected outcomes. Subsequently, the taskforce also determined what content would fit best into each phase of the program and what teaching and assessment methods would be more appropriate for each outcome. After a pilot curriculum with a small group of second-year medical students, we implemented this program for all first-year students since 2011 at TUMS. Based on findings, the teaching of four areas, including scientific and critical thinking skills (Basic sciences), problem-solving and reasoning (Pathophysiology), evidence-based medicine (Clerkship), and clinical decision-making (Internship) were considered in the form of a longitudinal theme. The results of this study could be utilized as a useful pattern for integration of psycho-social subjects into the medical curriculum

Herbicide control of the invasive Amur honeysuckle (Lonicera maackii) does not alter soil microbial communities or activity

Invasive plants are a major problem for land managers and have widespread and lasting environmental impacts. The invasive shrub Amur honeysuckle (Lonicera maackii) is a pervasive and noxious plant in the Midwest region of the United States. Despite this, many land managers may be uncomfortable with herbicide control of this and other invasive plants due to unknown impacts on ecosystem components including soils. To examine if herbicide control of Amur honeysuckle impacts soil enzyme activity and soil communities, we treated Amur honeysuckle with Garlon® 4 (triclopyr) suspended in Basal Bark Oil, Basal Bark Oil alone and untreated controls, then assessed soil community, soil enzyme activity and arbuscular mycorrhizal density changes among treatments and across the subsequent growing season. We found that basal bark herbicide treatments of Amur honeysuckle do not negatively impact soil enzyme activity, nor do they impact fungal, prokaryotic or oomycotan diversity or community structure. There was a slight but likely ecologically unimportant effect on community structure associated with basal bark oil applications, but not with herbicide applications. Arbuscular mycorrhizal colonization was negatively affected by herbicide use but this is likely due to reduction in host health and/or mortality. Taken together, this suggests that herbicide control of Amur honeysuckle does not impact soils and land managers can treat these invasive plants without concern for negative soil outcomes