Arabidopsis response to the spider mite Tetranychus urticae depends on the regulation of reactive oxygen species homeostasis

M Estrella Santamaría,Manuel Martinez,Isabel Diaz,Ana Arnaiz,Vojislava Grbic,Blanca Velasco-Arroyo

doi:10.1038/s41598-018-27904-1

Abstract

Reactive oxygen species (ROS) are molecules that play a prominent role in plant response to numerous stresses, including plant interactions with herbivores. Previous findings indicate that Arabidopsis plants showed an increase in H2O2 accumulation after Tetranychus urticae infestation. Despite its importance, no information has been reported on the relationships between ROS-metabolizing systems and the spider mite-triggered plant-induced responses. In this work, four ROS-related genes that were differentially expressed between the resistant Bla-2 and the susceptible Kon Arabidopsis accessions were selected for the analysis. 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 relative to the wild-type plants. Minor effects on H2O2 accumulation obscure major effects on the expression of genes related to ROS-metabolism and JA and SA signaling pathways, and on ROS-related enzymatic activities. In conclusion, the integration of ROS and ROS-related compounds and enzymes in the response of Arabidopsis to the spider mite T. urticae was confirmed. However, the complex network involved in ROS signaling makes difficult to predict the impact of a specific genetic manipulation.

Highlights

Plants, as sessile organisms, have to cope with hostile conditions derived from the attack of other organisms
Mining the dataset coming from these analyses, several functional categories related to Reactive oxygen species (ROS) homeostasis appeared over represented in transcriptomic comparisons related to T. urticae infestation or to resistance/susceptibility of Arabidopsis accessions (Table 1)
BBE22 would be involved in the generation of H2O2 from reduced compounds; AO would have the role in the degradation of ascorbate todehydroascorbate, and Glutathione peroxidase 7 (GPX7) and Glutathione S-transferase TAU 4 (GSTU4) in the degradation of H2O2 to water using glutathione as electron donor

Summary

Introduction

As sessile organisms, have to cope with hostile conditions derived from the attack of other organisms. Proteomic and metabolomic profiles after arthropod feeding, oviposition or application of insect secretions have demonstrated that plants may discriminate between herbivores to activate herbivore-specific plant responses[9,10,11,12]. These responses are regulated by a complex hormonal cross-talk centered at Jasmonic (JA) and Salicylic (SA) acids[13,14,15]. As ROS levels, especially H2O2, increase during herbivore feeding or egg deposition, a dual role has been attributed to ROS molecules as direct defenses and as a part of oxidative signaling pathways in plants[16]. Accumulating evidence supports the effect of herbivore infestation on stress signaling networks triggered by ROS and redox-sensitive factors including hormone-signaling pathways[5,20]

Methods

Results

Conclusion