Location: Emerging Pests and Pathogens Research
Project Number: 8062-22410-006-000-D
Project Type: In-House Appropriated
Start Date: Oct 1, 2015
End Date: Sep 30, 2020
Objective 1. Using and developing genetic resources and associated information of the ARS Collection of Entomopathogenic Fungal Cultures (ARSEF), conserve, characterize (including taxonomic revision), and exchange insect pathogenic fungi such as Beauveria, Metarhizium, and Hirsutella species complexes to facilitate use of these fungi as biocontrol agents of key arthropod pests and disease vectors. Subobjective 1.1. Continue the curation, operation, and expansion of the ARSEF culture collection and associated information resources. Subobjective 1.2. Improve methods to isolate, culture, and preserve fungal entomopathogens. Subobjective 1.3. Conduct research on the systematics, taxonomy, and organismal biology of these fungi. Objective 2. Identify genetic, environmental and behavioral mechanisms that regulate circulative transmission of insect-borne plant pathogens. Subobjective 2.1. Identification of pathogen, host, and vector components that regulate uptake and transmission of pathogens by sap-sucking insects. Subobjective 2.2. Functional analysis of genes, proteins and metabolites involved in circulative plant pathogen transmission. Objective 3. Explore the utility of novel interdiction molecules that could interfere with plant pathogen acquisition and transmission. Subobjective 3.1. Continue efforts to define the chemistry of fungal secondary metabolites and characterize their effects on phloem-feeding insects, their endosymbionts, and on plant pathogen transmission. Subobjective 3.2. Develop RNA aptamers that bind to transmission related compounds and test their ability to interfere with pathogen acquisition and transmission.
Control of arthropods that transmit pathogens is arguably one of the biggest challenges to human health and agriculture. Many serious plant and animal pathogens are dependent upon arthropod vectors for transmission between hosts. Nearly all arthropod-transmitted animal pathogens are internalized and circulate in their insect vectors, while plant pathogens are divided between those that circulate in their vectors and those that are carried on the cuticle linings of mouthparts and foreguts. The mechanisms of circulative transmission are only beginning to be dissected, but already commonalities among transmission of both circulative plant and animal pathogens have been discovered. Our experimental systems offer innovative approaches to manage circulative-transmitted plant pathogens that have been recalcitrant to the development of host resistance and for which the economic and environmental costs of vector control has been prohibitive, unsustainable and/or ineffective. Scientists' incomplete understanding of interactions among insect vectors, plant pathogens and plant hosts limits the development of new tools to block or interfere with pathogen transmission by insects in the field. We address this problem by attempting to discover genes and products that mediate the associations among insect vectors, circulative plant pathogens and plant hosts. The new technologies and knowledge are expected to be extended and applied to the study of other circulative pathogens and will greatly impact growers, industry stakeholders, and other research communities. The project will also focus on maintaining the extensive ARS Collection of Entomopathogenic Fungal Cultures (ARSEF). ARSEF contains 12,500 isolates representing 700 fungal taxa from 1,300 hosts and 2,400 locations worldwide, and will be managed to ensure ongoing accession, preservation, identification, and distribution of fungal isolates for development and deployment as biocontrol agents and for research purposes. The ARSEF collection also plays a central role in revising taxonomies of fungi using the state-of-the-art systematic methods.