GENOMIC CHARACTERIZATION OF TRICHODERMA ATROBRUNNEUM (T. HARZIANUM SPECIES COMPLEX) STRAIN ITEM 908, A BIOCONTROL AGENT OF FUSARIUM GRAMINEARUM

Trichoderma atrobrunneum F.B. Rocha, P. Chaverri& W. Jaklitsch strain ITEM 908 (formerly known as T. harzianum ITEM 908), is a biocontrol strain that is being registered under the European Union regulation as an active ingredient for the production of commercial biopesticides. The strain ITEM 908 proved to be able to inhibit completely the formation of perithecia by Fusarium graminearum in dual cultures and to release in the agar medium metabolites that reduce the number of perithecia by over 70% (Altomare et al., poster presentation in this Congress). Therefore, ITEM 908 appears to be a good candidate biocontrol strain for prevention of Fusarium Head Blight (FHB) in the field by treatment of plant residues of the preceeding crop, thus reducing the primary inoculum. For the univocal characterization of this commercially valuable isolate and as a base for further studies aimed at elucidating its mechanisms of action and its physiological and molecular interactions with plants and target pathogens and pests, we sequenced the whole genome of the strain ITEM 908. The genome was sequenced on an Ion S5 platform generating around 7M bpand assembled using the Spades v5.0 software. The resulting genome sequence has an estimated size of 39,131,654 bp. The reference gene sequences of ITS and TEF1 were extracted from the genome assembly. The identification of the strain ITEM 908 at species level was obtained by phylogenetic analysis with Maximum likelihood (ML) analysis performed with one-hundred ITS-TEF1 manually concatenated dataset retrieved from sequences of Trichoderma spp. deposited in GenBank. The analysis placed ITEM 908 within the T. atrobrunneum group, close to T. afroaharzianum and T. guizhouense. Genome was annotated using the Augustus v3.1 software and 8649 genes were predicted. Approximately 3000 different pfam domains were detected and used to group genes within functional categories, including glycoside hydrolases, proteases and gene involved in stress tolerance and in secondary metabolites biosynthesis. Among these, 20 putative PKS, 8 putative NRPS and 5 putative PKS-NRPS were identified. Moreover, the secretome of T. atrobrunneum ITEM 908, consisting of 761 proteins, was in silico predicted by the software SignalP (http://www.cbs.dtu.dk/services/SignalP/), that detects the presence of the secretion signal peptide at the N-terminus in amino acid sequences of a protein.The preliminary analysis of predicted genes highlights the potential ability of T. atrobrunneum ITEM 908 to produce a broad range of enzymes involved in the biocontrol activity