Location: Emerging Pests and Pathogens Research
Project Number: 8062-21000-048-006-A
Project Type: Cooperative Agreement
Start Date: Sep 1, 2021
End Date: Aug 31, 2025
Objective:
The research to be conducted under this agreement is designed to identify the range of bacterial species and strains responsible for soft rot diseases (e.g., potato blackleg disease) and to identify sources of disease inoculum and trace how these bacteria enter and move through plant production and cropping systems. This information will be used for risk assessment, to support decisions and allocation of resources, to design diagnostic methods, and to focus development of control methods that target agriculturally relevant pathogens. ARS will also investigate novel strategies of disease control that exploit bacterial systems responsible for controlling invasive behavior.
Approach:
Designing methods to diagnose and control bacterial plant diseases currently relies on knowing the range of bacteria responsible, how the pathogens interact with the host and their environment. ARS will work with our cooperator to identify pathogens responsible for plant diseases using a combination of classical plant pathology methods combined with state of the art genome sequencing methods. Our cooperator will use computational methods to analyzed genome sequence data to identify bacteria responsible for diseases and to determine the diversity among these bacteria. ARS will combine this information with geographical origin of diseased samples and information about movement of plant materials to identify the sources of disease inoculum.
The most sustainable method to control these types of diseases is to use resistant plants. Our cooperator will conduct research to identify new sources of resistance including, screening wild crop relatives for plants that are naturally resistant to disease. Screening involves testing the disease sensitivity/resistance of individual plants or plant parts. Our cooperator will identify genetic loci associated with disease resistance and design molecular probes to test the inheritance of resistance in order to speed breeding resistance in cultivated varieties.
An understanding of the biology of the bacteria responsible for these diseases is also critical to design or implement disease control. ARS has identified evidence of an uncharacterized system that controls bacterial invasive behavior according to their social environment. Specifically, bacteria are induced to behave more aggressively when they are in proximity to unrelated bacteria; and conversely, they are less invasive when they are in proximity to related bacteria. Our cooperator will use genomic and molecular biology methods to identify genes and molecules responsible for detecting the genetic relationship between proximal individuals and for the different behaviors that occur depending on those relationships.
