Infiltration-RNAseq Reveals Enhanced Defense Responses in Nicothiana benthamiana Leaves Overexpressing the Banana Gene MaWRKY45

The banana gene <i>MaWRKY45</i> gene encodes a WRKY transcription factor (TF) that is closely related to <i>OsWRKY45</i>, which is a master regulator of defense responses in rice. MaWRKY45 is a transcription factor with proven transactivation activity and nuclear localization. Its expression is upregulated by the defense phytohormones salicylic acid (SA) and jasmonic acid (JA). Despite these findings, its transcriptome-wide impact during overexpression remains unexplored. Accordingly, the present study employed the Infiltration-RNAseq method to identify differentially expressed genes (DEGs) resulting from the overexpression of <i>MaWRKY45</i> in the leaves of the model plant <i>Nicotiana benthamiana</i>. A total of 2473 DEGs were identified in <i>N. benthamiana</i> leaves overexpressing the banana gene <i>MaWRKY45</i>. Of these, 1092 were up-regulated and 1381 were down-regulated. Among the genes that were found to be up-regulated, those encoding proteins that are involved in plant immunity were identified. These included disease resistance receptors, proteins that are involved in cell wall reinforcement, proteins that possess antimicrobial and insecticidal activities, and defense-related TFs. It was thus concluded that the function of the banana gene <i>MaWRKY45</i> is associated with the plant immune system, and that its overexpression can lead to enhance defense responses.