Project description:Metagenome data from soil samples were collected at 0 to 10cm deep from 2 avocado orchards in Channybearup, Western Australia, in 2024. Amplicon sequence variant (ASV) tables were constructed based on the DADA2 pipeline with default parameters.
Project description:Tomato plants are commonly attacked by herbivorous mites, including by generalist Tetranychus urticae and specialists Tetranychus evansi and Aculops lycopersici. Mite feeding induces plant defense responses that reduce mite performance. However, via poorly understood mechanisms, T. evansi and A. lycopersici suppress plant defenses and, consequently, maintain a high performance on tomato. Accordingly, on a shared host, non-adapted T. urticae can be facilitated by either of the specialist mites, likely via the suppression of plant defenses. To better understand defense suppression and indirect plant-mediated interactions between herbivorous mites, we used microarrays to analyze transcriptomic changes in tomato after attack by either a single mite species (T. urticae, T. evansi, A. lycopersici) or two species simultaneously (T. urticae plus T. evansi or T. urticae plus A. lycopersici). Additionally, we assessed mite-induced changes in defense-associated phytohormones using LC-MS/MS. Compared to non-infested controls, jasmonates (JAs) and salicylate (SA) accumulated to higher amounts upon all mite-infestation treatments, but lowest increases were detected after single infestations with defense-suppressors. Strikingly, whereas 8 to 10% of tomato genes was differentially expressed upon single infestations with T. urticae or A. lycopersici, only 0.1% was altered in T. evansi-infested plants. Transcriptome analysis of dual-infested leaves revealed that T. evansi dampened T. urticae-triggered host responses on a genome-wide scale, while A. lycopersici primarily suppressed T. urticae-induced JA defenses. Our results provide valuable new insights into the mechanisms underlying host defense suppression and the plant-mediated facilitation of competing herbivores.
