Molecular and Transcriptomic Studies of Sphaerodes mycoparasitica–Fusarium graminearum–Triticum durum Interactome Shed Light on Biotrophic Mycoparasitism

Abstract

Sphaerodes mycoparasitica Vujan. SMCD 2220-01, a specific biotrophic mycoparasite demonstrates unique biocontrol properties against plant pathogenic and mycotoxigenic Fusarium hosts. Fusarium head blight (FHB) is a major fungal disease in cereal crops caused by Fusarium graminearum complex. FHB has continued to generate significant losses in seed germination, grain yield, and quality, thus negatively affecting global food safety and security which merits particular scientific attention. This research study results provide a new insight on the “interactome” or biocontrol agent–plant pathogen–plant host interaction in co-culture based on the combination of molecular, transcriptomic, and biochemical analyses. Observing changes in improved seed germination, fungus-fungus interface through next-generation HiSeq DNA/RNA sequencing validated with quantitative real-time PCR (qPCR), scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), transmission electron microscopy (TEM), and FTIR molecular signatures combined with principal component analysis (PCA) proved useful tools to detect an early mycoparasitism as a vital asset of the preventive biocontrol strategy against mycotoxigenic Fusarium pathogens in staple crops and its mycotoxins in food products. The NGS-transcriptomic data provided a better understanding of the evolutionary history of S. mycoparasitica as a specific mycoparasite. Further, the similar and dissimilar patterns of the gene expression of this mycoparasite during the biotrophic mycoparasitism on F. graminearum implied that this mycoparasite developed a very unique lifestyle compared with other general (necrotrophic) mycoparasites.