Dual RNA-Seq reveals the role of a transcriptional regulator gene in pathogen-host interactions between Pseudomonas plecoglossicida and Epinephelus coioides

Abstract Pseudomonas plecoglossicida is a highly pathogenic bacterium for maricultured fish and causes serious losses. A transcriptional regulator gene RK21_RS10315 was found up-regulated during the whole infection process, which was confirmed by qRT-PCR. Five shRNA were designed to silence RK21_RS10315 gene, and the gene expression was reduced up to 96.1%. Compared with the counterpart infected with wild type strain, the infection of RK21_RS10315 -RNAi strain resulted in the death time delay, and 90% reduction in mortality of Epinephelus coioides , as well as the alleviation in the symptoms of E. coioides spleen. Moreover, compared with the fish infected with wild type strain, the infection of RK21_RS10315 -RNAi strain of P. plecoglossicida resulted in a significant change both in transcriptome of spleen of infected E. coioides and P. plecoglossicida . The KEGG analysis showed that genes of 16 immune pathways in E. coioides were affected by the silence of RK21_RS10315 of P. plecoglossicida . Among them, intestinal immune network for IgA production pathway and leukocyte transendothelial migration pathway were more prominent than other pathways. 19 euk-DEMs in these immune pathways had varying degrees of correlation with 19 pro-DEMs, and the expression of ipxA , grpE , yhbJ , truD and suhB from 19 pro-DEMs were predicted more related to RK21_RS10315 in P. plecoglossicida .