IPA-1 a Putative Chromatin Remodeler/Helicase-Related Protein of Plays Important Roles in Antibiosis Against and Induction of Systemic Disease Resistance.

spp. are filamentous fungi that colonize plant roots conferring beneficial effects to plants, either indirectly through the induction of their defense systems or directly through the suppression of phytopathogens in the rhizosphere. Transcriptomic analyses of spp. 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 during its interaction with seedlings. The main response of to cocultivation with 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 in 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 the auxiliary activities class. RNA-Seq analyses showed the induction of a member of the SNF2 family of chromatin remodelers/helicase-related proteins, which was named IPA-1 (increased protection of -1). Sequence analyses of IPA-1 showed its closest relatives to be members of the Rad5/Rad16 and SNF2 subfamilies; however, it grouped into a different clade. Although deletion of in did not affect its growth, the antibiotic activity of Δ culture filtrates against diminished but it remained unaltered against . Triggering of the plant defense genes in plants treated with Δ was higher, showing enhanced resistance against but not against as compared with the wild type.