Identification Of MicroRNAs Associated With Resistance To Cotton Bollworm (Helicoverpa Armigera) In Wild Soybean By Comparing Microrna Profilings Between Resistant And Susceptible Bulks

MiRNAs played important roles in regulating plant defense against stresses. Soybean (Glycine max) is an important oil and protein crop. Cotton bollworm (Helicoverpa armigera) is one of the major chewing insects that damage the soybean production worldwide. To date, no miRNAs associated with resistance to defoliating insects was reported in soybean. A wild soybean (Glycine soja), ED059, was reported to have a high level of resistance to H. armigera. In this study, we conducted miRNA profilings for the resistant and susceptible bulks of F2 population from a cross between ED059 and a susceptible soybean cultivar (cv.) Tianlong 2. The constitutive and inducible miRNAs associated with resistance to H. armigera were identified. In addition, the miRNAs in response to wounding were also detected. Functional analyses for the miRNA targets showed that the high level of resistance to H. armigera in ED059 might be associated with calcium-dependent protein kinases (CDPKs) signaling pathway, cytochrome P450, ethylene biosynthesis pathway and leucine rich repeat (LRR) receptor serine/threonine kinase. This study was the first report about soybean miRNAs associated with resistance to H. armigera, which could contribute to the elucidation of the defense mechanism against chewing insects in plants.