GSE125225
Transcriptomic analysis of the Trichoderma virens- Arabidopsis thaliana interaction
Trichoderma spp. are filamentous fungi that colonize plant roots conferring beneficial effects to plants, indirectly through the induction of their defense systems or directly through the suppression of phytopathogens in the rhizosphere. Transcriptomic analyses of Trichoderma emerged as a powerful method for identifying the molecular events underlying the establishment of this beneficial relationship. Here, we focus on the transcriptomic response of Trichoderma virens during its interaction with Arabidopsis seedlings. The main response of T. virens to co-cultivation with Arabidopsis was the repression of gene expression. The biological processes of transport and metabolism of carbohydrates were downregulated, including a set of cell-wall-degrading enzymes putatively relevant for root-colonization. Repression of such genes reached their basal levels at later times of the interaction when genes belonging to the biological process of copper ion transport were induced, a necessary process providing copper as a cofactor for cell-wall degrading enzymes with auxiliary activities (AAs) class. RNA-Seq analysis showed the induction of a member of the SNF2 family of chromatin remodelers/helicase-related proteins, which was named IPA-1 (Increased Protection of Arabidopsis-1). Sequence analyses of IPA-1 showed as its closest relatives members of the Rad5/Rad16- and SNF2-subfamilies; however, it grouped into a different clade. Although deletion of ipa-1 in T. virens did not affect its growth, the antibiosis of ?ipa-1 culture filtrates showed a diminished effect against Rhizoctonia solani but remained unaltered against Botrytis cinerea. Triggering of the plant defense genes in plants treated with ?ipa-1 was higher, showing enhanced resistance against Pseudomonas syringae but not against B. cinerea as compared to wild type. Overall design: Twenty ten-day-old Arabidopsis seedlings grown on MS 1× plates were root inoculated with T. virens WT (wild-type), and mycelia were collected at 48, 72 and 96 hpi (hours post inoculation). T. virens growing in MS 1× plates were used as control. RNA total of three biological replicates was used to construct the RNA-seq libraries for each treatment.