Complete genome of Streptomyces anulatus DEF39, an endophytic biocontrol agent against Fusarium graminearum
Phylogenetic and functional genomic analyses were carried out to help explaining the endophytic lifestyle and the biocontrol activity of Streptomyces sp. strain DEF39, able to reduce Fusarium graminearum infection as well as deoxynivalenol production in wheat plants. Specifically, in this work, genes and biosynthetic pathways linked to secondary metabolite production, biocontrol activity, and plant interactions were identified. This approach supports the experimentally validated capability of DEF39 to protect plants from fungal diseases, highlighting the potential of genomics studies. Streptomyces sp. DEF39 was isolated as an endophyte from Secale cereale in Italy and has been shown to colonize wheat ( Triticum spp.) and act as a biocontrol agent of Fusarium head blight. The complete genome (9.12 Mb) (GCA_978019405.1), assembled through a hybrid strategy based on long and short accurate reads combination, is composed of a linear chromosome of 8,887,323 bp with a GC content of 71.59% and a linear plasmid of 233,172 bp with a GC content of 69.27%. Phylogenetic analyses based on the whole genome demonstrated that DEF39 belongs to Streptomyces anulatus species (ANI and dDDH value of 99.13% and 92.8%, respectively with the reference genome GCA_001434355.1). Functional annotation revealed 9,556 genes (CDS). Respectively, antiSMASH and PLaBAse bioinformatic tools predicted 15 putative secondary metabolite biosynthetic gene clusters, as well as 5,203 genes putatively associated with plant growth promotion.