MATI, a Novel Protein Involved in the Regulation of Herbivore-Associated Signaling Pathways

Abstract

The defense response of the plants against herbivores relies on a complex network of interconnected signaling pathways. In this work, we characterized a new key player in the response of Arabidopsis against the two-spotted spider mite Tetranychus urticae, the MATI (Mite Attack Triggered Immunity) gene. This gene was differentially induced in resistant Bla-2 strain relative to susceptible Kon Arabidopsis accessions after mite attack, suggesting a potential role in the control of spider mites. To study the MATI gene function, it has been performed a deep molecular characterization of the gene combined with feeding bioassays using modified Arabidopsis lines and phytophagous arthropods. The MATI gene belongs to a new gene family that had not been previously characterized. Biotic assays showed that it confers a high tolerance not only to T. urticae, but also to the chewing lepidopteran Spodoptera exigua. Biochemical analyses suggest that MATI encodes a protein involved in the accumulation of reducing agents upon herbivore attack to control plant redox homeostasis avoiding oxidative damage and cell death. Besides, molecular analyses demonstrated that MATI is involved in the modulation of different hormonal signaling pathways, affecting the expression of genes involved in biosynthesis and signaling of the jasmonic acid and salicylic acid hormones. The fact that MATI is also involved in defense through the modulation of the levels of photosynthetic pigments highlights the potential of MATI proteins to be exploited as biotechnological tools for pest control.

Plant Defenses Against Tetranychus urticae: Mind the Gaps

“…It has also been reported that the effect of the mite attack triggered immunity (MATI) gene involved in the maintenance of the thale cress antioxidant status was correlated with the spider mite performance. MATI-overexpressing plants led to a moderate H 2 O 2 accumulation and increased thale cress resistance to spider mite attack as reflected by lesser leaf damage and the reduced mite fecundity observed in comparison to the symptoms and oviposition rates quantified in control and mutant plants [70].…”

“…However, not only the JA pathway is activated after spider mite infestation. The induction of both JA and SA pathways has been reported in spider mite infested thale cress [42,64,70], tomato [44,47], citrus [40,43,80] and pepper [46], among other plant species. Moreover, He et al [81] also reported the accumulation of SA and conjugated-SA forms induced by spider mite attack in bean (Phaseolus vulgaris) leaves but the JA content was not analyzed in this study.…”

“…Also, some reports have demonstrated that T. urticae infestation produces cell damage that leads to alterations in cytosolic Ca 2+ levels and Vm variations accompanied by ROS production [58]. Accumulation of ROS and phenolic compounds at the wounding sites caused by T. urticae in barrelclover (Medicago truncatula) and thale cress plants have been reported [2,[68][69][70] and ascorbate, in response to T. urticae infestation. Silencing of the three genes involved in ROS degradation resulted in higher leaf damage and better mite performance in comparison to wild-type plants.…”

Can Plant Defence Mechanisms Provide New Approaches for the Sustainable Control of the Two-Spotted Spider Mite Tetranychus urticae?

“…Accordingly, the relevance of IGs in defence was assessed using IG mutant lines on which the development of T. urticae was increased. A microarray analysis of spider mites reared on IG mutants or wild-type plants showed that the increased expression of detoxification genes such as P450 monooxygenases, glycosyltransferases, and lipocalins correlated with IG levels [ 89 , 105 ]. Note that the implication of glucosinolates was demonstrated using lines grown on Phaseolus vulgaris .…”

HvPap-1 C1A Protease Participates Differentially in the Barley Response to a Pathogen and an Herbivore

“…The retarded induction of HvPap-1 after spider mite infestation could be more related to senescence processes associated to leaf damage. This hypothesis is supported by the fact that jasmonic acid not only triggers defensive responses against herbivores but also leaf senescence ( Reinbothe et al, 2009 ), and the reported induction of the jasmonic acid biosynthesis and signaling pathways after spider mite feeding ( Ament et al, 2004 ; Martel et al, 2015 ; Santamaria et al, 2017 ). Therefore, if the induction of HvPap-1 is due to different mechanisms, the analysis of the transcriptome in silencing or overexpressing HvPap-1 lines could help to understand the differential responses to pathogen and herbivore stresses.…”