Expression of the shrimp antimicrobial peptide penaeidin 4-1 confers resistance against brown patch disease in tall fescue

Tall fescue ( Festuca arundinacea Schreb.) is an important grass widely used in North Carolina and other transition zone states in the US for turf and as forage. Brown patch caused by subgroup AG1-AI of Rhizoctonia solani is the most severe and frequently occurring fungal disease for tall fescue plants. The objective of this research was to genetically engineer tall fescue to improve its resistance to the pathogen. The gene ( Pen4 - 1 ) of a novel antimicrobial peptide—Penaeidin 4-1 from a shrimp species was introduced into tall fescue var. ‘Coronado’ through Agrobacterium -mediated transformation. Among the five transgenic plants containing the Pen4 - 1 transgene, four of them displayed significantly higher level of resistance against R. solani subgroup AG1-IA, with two being highly resistant ( p < 0.001). Up to 75 % reduction of the lesion size was achieved. The results indicate that Pen4 - 1 confers resistance to various subgroups of R. solani and is a promising candidate for engineered resistance to a wide-spectrum pathogens in tall fescue.