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ARS Home » Midwest Area » St. Paul, Minnesota » Plant Science Research » Research » Publications at this Location » Publication #363397

Research Project: Enhanced Alfalfa Germplasm and Genomic Resources for Yield, Quality, and Environmental Protection

Location: Plant Science Research

Title: Combating crown rot with antimicrobial peptides

item SATHOFF, ANDREW - University Of Minnesota
item Samac, Deborah - Debby

Submitted to: Forage Focus
Publication Type: Trade Journal
Publication Acceptance Date: 4/22/2019
Publication Date: 5/15/2019
Citation: Sathoff, A., Samac, D.A. 2019. Combating crown rot with antimicrobial peptides. Forage Focus. 5:6-7.

Interpretive Summary:

Technical Abstract: When attacked by a disease-causing microorganism, plants and animals respond in a similar way by producing small antimicrobial proteins or peptides that slow down or kill the pathogen. This ancient form of disease protection is gaining recognition as a means to battle antibiotic resistance and improve animal and plant health. Scientists with USDA-ARS in St. Paul, MN and colleagues at the University of Minnesota and Donald Danforth Center in St. Louis, MO investigated one type of antimicrobial peptides called plant defensins as a means to reduce the damage from crown rot disease in alfalfa. To identify defensins with the required broad activity against alfalfa pathogens, core amino acid sequences that are required for activity were tested against fungal, bacterial and oomycete pathogens of alfalfa. The peptides from barrel medic, an annual medic closely related to alfalfa, were the most active against crown rot pathogens. The gene for the most active barrel medic defensin was used to generate transgenic alfalfa plants that steadily express the defensin throughout the plant. In preliminary experiments, plants show increased resistance to foliar pathogens. Transgenic expression of defensins could be utilized to implement an eco-friendly, protein-based strategy that could provide alfalfa with enhanced resistance against crown rot and the correlative increases in forage yield and stand life.