Functional Identification of miR2119 Targeting <i>ADHs</i> in Modulating Soybean Resistance to <i>Heterodera glycines</i>

Soybean cyst nematode (SCN, <i>Heterodera glycines</i>) is a sedentary endoparasite nematode that results in severe economic losses in soybean crops. miRNAs play crucial roles in plant responses to nematode. However, the role of miR2119 responding to SCN stress in soybean. Here, we demonstrated that the transcript levels of polycistronic precursors containing miR2119 and miR398a were significantly reduced in soybean upon nematode infection. Promoter of the miR2119-398a precursor analysis was conducted containing a <i>GUS</i> reporter gene. GUS activity assays demonstrated a decrease in miR2119-398a promoter during SCN infection. Overexpression of polycistronic precursor miR2119-398a (OE-premiR2119-398a) and miR2119 precursor (OE-premiR2119) rendered soybean more susceptible to SCN. Conversely, silencing miR2119 (STTM2119) increased soybean resistance against SCN. Furthermore, RNA-seq analysis revealed that miR2119 is involved in many defense signaling pathways. <i>GUS</i> reporter gene assays demonstrated that miR2119 targets <i>GmADH1.1a</i> and <i>GmADH1.1b</i>. Functional analysis indicated that <i>ADHs</i> act as a major role in responding to <i>H. glycines</i> by modulating reactive oxygen species (ROS) levels. Together, the findings reveal a novel mechanism by which the polycistronic precursor miR2119-398a coordinately regulates in response to <i>H. glycines</i>. Additionally, miR2119 becomes an essential element contributing to <i>H. glycines</i> by modulating <i>ADH</i> activity and ROS homeostasis in soybean.