A search for an effective control measure against root-rot in field pea: Effect of antimicrobial peptides on in vitro growth of Aphanomyces euteiches.

Dry field pea (Pisum sativum L.) is an important export crop grown in the Canadian prairies. With the recognition of benefits of plant-based proteins in human diet, and the fact that field pea has a high protein content in seeds, the demand of this crop is expected to grow significantly. In addition, because of its nitrogen fixing ability which enables it to keep a low carbon footprint, field pea has gained further importance in crop cultivation choices. However, a growing presence of root-rot pathogens in the Prairies fields and lack of effective control measures have seriously threatened the pea production system. Aphanomyces euteiches is one of the pathogens responsible for root-rot that infects seedlings resulting in severely reduced plant growth and seed yield, thus causing substantial economic losses. Long-lived dormant oospores of the pathogen in soil make it difficult to mange the disease. Here in this study, we are exploring to assess the efficacy of antimicrobial peptides (AMPs), which are a part of plant innate immunity but have a different mechanism of action than classical R-genes, against A. euteiches. Thirteen AMPs were tested for their ability to inhibit the growth of A. euteiches under in vitro conditions. Using a resazurin stain assay the inhibitory concentration (IC50) values of the AMPs were determined. The most effective AMPs were PN60 and PN51 with average IC50 values of 3.03 and 0.79 uM, respectively. A highly potent activity of these peptides was very promising which can be further developed into a novel approach to manage A. euteiches-induced root rot in field pea.