A complex network of ROS regulation is involved in the defence response of Arabidopsis against the two-spotted spider mite

Researchers from the CBGP (UPM-INIA) group “Plant-pest molecular interactions” have revealed the existence of a complex network involving reactive oxygen species (ROS), related compounds and enzymatic activities. This network plays a key role in the defence response of Arabidopsis against the two-spotted spider mite, an important pest able to feed on many crops.

For that, four ROS-related genes that were differentially expressed between the resistant Bla-2 and the susceptible Kon Arabidopsis accessions were selected. These genes encode proteins putatively involved in the generation (BBE22) and degradation (GPX7 and GSTU4) of H2O2, and in the degradation of ascorbate (AO). Overexpressing BBE22 and silencing GPX7, GSTU4 and AO resulted in higher leaf damage and better mite performance. These effects were accompanied to major changes on the expression of genes related to ROS-metabolism and JA and SA signaling pathways, and on ROS-related enzymatic activities.