The Entomopathogenic Fungus Metarhizium anisopliae Affects Feeding Preference of Sogatella furcifera and Its Potential Targets’ Identification

The rice planthopper Sogatella furcifera is a unique vector of the southern rice black-streaked dwarf virus (SRBSDV). The feeding behavior of S. furcifera should directly affect the diffusion of this virus. In this study, we noted that the infection of Metarhizium anisopliae CQMa421 on S. furcifera disturbed the feeding behavior of this pest to SRBSDV-infected rice, from preference to non-preference. Then, we further investigated the potential targets of M. anisopliae CQMa421 on the feeding behavior of S. furcifera after 0 h, 24 h and 48 h of infection by transcriptomic analysis via Illumina deep sequencing. A total of 93.27 GB of data was collected after sequencing, from which 91,125 unigenes were annotated, including 75 newly annotated genes. There were 1380 vs. 2187 and 137 vs. 106 upregulated and downregulated differentially expressed genes (DEGs) detected at 24 h and 48 h, respectively. The biological functions and associated metabolic processes of these genes were determined with the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. The results suggested that major of DEGs are involved in energy metabolism, biosynthesis, immune response, the FoxO signaling pathway, the MAPK signaling pathway and apoptosis in response to the fungal infection. Noteworthily, several olfactory-related genes, including odorant receptors and odorant binding proteins, were screened from these differentially expressed genes, which played critical roles in regulating the olfactory behavior of insects. Taken together, these results provide new insights for understanding the molecular mechanisms underlying fungus and host insect interaction, especially for olfactory behavior regulated by fungus.