Gma-miR408 Enhances Soybean Cyst Nematode Susceptibility by Suppressing Reactive Oxygen Species Accumulation

Abstract

Soybean cyst nematode (SCN, <i>Heterodera glycine</i>) is a serious damaging disease in soybean worldwide, thus resulting in severe yield losses. MicroRNA408 (<i>miR408</i>) is an ancient and highly conserved miRNA involved in regulating plant growth, development, biotic and abiotic stress response. Here, we analyzed the evolution of <i>miR408</i> in plants and verified four <i>miR408</i> members in <i>Glycine max</i>. In the current research, highly upregulated <i>gma-miR408</i> expressing was detected during nematode migration and syncytium formation response to soybean cyst nematode infection. Overexpressing and silencing <i>miR408</i> vectors were transformed to soybean to confirm its potential role in plant and nematode interaction. Significant variations were observed in the MAPK signaling pathway with low OXI1, PR1, and wounding of the overexpressing lines. Overexpressing <i>miR408</i> could negatively regulate soybean resistance to SCN by suppressing reactive oxygen species accumulation. Conversely, silencing <i>miR408</i> positively regulates soybean resistance to SCN. Overall, <i>gma-miR408</i> enhances soybean cyst nematode susceptibility by suppressing reactive oxygen species accumulation.