Analysis of Saprolegnia parasitica Transcriptome following Treatment with Copper Sulfate

Abstract

BackgroundMassive infection caused by oomycete fungus Saprolegnia parasitica is detrimental to freshwater fish. Recently, we showed that copper sulfate demonstrated good efficacy for controlling S. parasitica infection in grass carp. In this study, we investigated the mechanism of inhibition of S. parasitica growth by copper sulfate by analyzing the transcriptome of copper sulfate—treated S. parasitica. To examine the mechanism of copper sulfate inhibiting S. parasitica, we utilized RNA-seq technology to compare differential gene expression in S. parasitica treated with or without copper sulfate.ResultsThe total mapped rates of the reads with the reference genome were 90.50% in the control group and 73.50% in the experimental group. In the control group, annotated splice junctions, partial novel splice junctions and complete novel splice junctions were about 83%, 3% and 14%, respectively. In the treatment group, the corresponding values were about 75%, 6% and 19%. Following copper sulfate treatment, a total 310 genes were markedly upregulated and 556 genes were markedly downregulated in S. parasitica. Material metabolism related GO terms including cofactor binding (33 genes), 1,3-beta-D-glucan synthase complex (4 genes), carboxylic acid metabolic process (40 genes) were the most significantly enriched. KEGG pathway analysis also determined that the metabolism-related biological pathways were significantly enriched, including the metabolic pathways (98 genes), biosynthesis of secondary metabolites pathways (42 genes), fatty acid metabolism (13 genes), phenylalanine metabolism (7 genes), starch and sucrose metabolism pathway (12 genes). The qRT-PCR results were largely consistent with the RNA-Seq results.ConclusionOur results indicate that copper sulfate inhibits S. parasitica growth by affecting multiple biological functions, including protein synthesis, energy biogenesis, and metabolism.

Saprolegnia parasitica Isolated from Rainbow Trout in Korea: Characterization, Anti-Saprolegnia Activity and Host Pathogen Interaction in Zebrafish Disease Model

“…Contrast to this phenomenon, Ssp1 has been shown as producing antibodies against saprolegniosis resistant fish [ 51 ]. Htp1 is translocated into host cells [ 52 ], and it has been found that copper sulfate treatment did not alter Htp1 mRNA expression [ 53 ]. Thus, in this study, the question arises whether lawsone has any influence on S. parasitica for inducing or suppressing the virulence effect, which needs to be studied more detail in future.…”

“…9F ) at each tested time points. Similarly, Upase and Oatt mRNA expression have been down-regulated in copper sulphate treated S. parasitica , however, contrastively, Treh mRNA expression has been up-regulated [ 53 ]. As a whole, our data suggest that lawsone has ability to directly altering the expression of genes encoding key cellular processes such as protein synthesis and metabolism which is likely to function for suppression of S. parasitica .…”

The Rare Sugar Tagatose Differentially Inhibits the Growth of Phytophthora infestans and Phytophthora cinnamomi by Interfering With Mitochondrial Processes

“…The attempted cellular responses of P. infestans against tagatose included the upregulation of maai, which is homologous to gst genes commonly upregulated by oxidative stresses (Montibus et al, 2015). The maai gene is a marker of stress responses and its expression was also upregulated by the biocontrol agent Lysobacter capsici AZ78 in P. infestans (Tomada et al, 2017) and by copper sulfate in Saprolegnia parasitica (Hu et al, 2016). In addition, tagatose upregulated the expression of aif in P. infestans and it encoded a protein involved in ROS scavenging (Klein et al, 2002) and mitochondrial cristae regulation (Cheung et al, 2006) in mammalian cells.…”

Dual RNA‐Seq of Lysobacter capsici AZ78 – Phytophthora infestans interaction shows the implementation of attack strategies by the bacterium and unsuccessful oomycete defense responses

“…(Gkarmiri et al, 2015). An attempted defense reaction of Pi against Lc was also suggested by the upregulation of genes encoding a pleiotropic drug resistance family protein possibly involved in toxin extrusion (Connolly et al, 2005) and a maleylacetoacetate isomerase possibly involved in the aromatic amino acid metabolism under abiotic stress (Hu et al, 2016). Moreover, genes encoding Kazallike protease inhibitors involved in the inactivation of plant proteolytic activities (Tian et al, 2005) were up-regulated, suggesting that they could be involved in the attempted inactivation of Lc lytic enzymes, as reported for R. solani in response to Serratia spp.…”