Identification of miRNAs Involved in Maize-Induced Systemic Resistance Primed by Trichoderma harzianum T28 against Cochliobolus heterostrophus .

microRNAs (miRNAs) are known to play important roles in the immune response to pathogen infection in different plants. Further, strains are able to activate plant defense responses against pathogen attacks. However, little is known about the involvement of miRNAs in the defense response primed by strains. To explore the miRNAs sensitive to priming by , we studied the small RNAs and transcriptome changes in maize leaves that were systemically induced by seed treatment with (strain T28) against () infection in leaves. Through analysis of the sequencing data, 38 differentially expressed miRNAs (DEMs) and 824 differentially expressed genes (DEGs) were identified. GO and KEGG analyses of DEGs demonstrated that genes involved in the plant hormone signal transduction pathway and oxidation-reduction process were significantly enriched. In addition, 15 miRNA-mRNA interaction pairs were identified through the combined analysis of DEMs and DEGs. These pairs were supposed to play roles in the maize resistance primed by T28 to , in which miR390, miR169j, miR408b, miR395a/p, and novel miRNA (miRn5231) were more involved in the induction of maize resistance. This study provided valuable information for understanding the regulatory role of miRNA in the primed defense response.