Combination analysis of the physiology and transcriptome provides insights into the mechanism of silver nanoparticles phytotoxicity.

Silver nanoparticles (AgNPs) have adverse impacts on plants when released into environments, but their toxic mechanism is still a matter of debate. Here we present a combined analysis of physiology and transcriptome of Arabidopsis thaliana leaves exposure to 30 mg L-1 AgNPs and Ag+ for six days to explore the toxicity mechanism of AgNPs on Arabidopsis. Both transcriptomic and physiological results showed that AgNPs induced reactive oxygen species (ROS) accumulation and damaged photosynthesis. The toxicity of AgNPs is not merely attributable to Ag+ release and much higher photosynthetic toxicity and ROS accumulation were observed in 30 mg L-1 AgNPs than that in 0.12 mg L-1 Ag+. About 60% genes were similarly up- or down-regulated at the same concentration of AgNPs and Ag+ and these genes were enriched in photosynthesis and response to the stimulus. However, 302 genes, including those involved in glucosinolates synthesis, were specifically regulated under AgNPs treatments. In conclusion, more than the released Ag+, nanoparticle-specific effects are responsible for the toxicity of AgNPs in Arabidopsis thaliana.

Identification of two severe fever with thrombocytopenia syndrome virus strains originating from reassortment.

Recently, a novel bunyavirus, severe fever with thrombocytopenia syndrome virus (SFTSV), was isolated in central China. The virus can cause multi-clinical symptoms: severe fever, thrombocytopenia, leukocytopenia, with a mortality rate of ~10%. Several studies show that SFTSV could undergo rapid evolution via gene mutation and homologous recombination. However, as an important evolutionary force for segmented-genome viruses, reassortment has not been reported in SFTSV. In this study, we identified two SFTSV strains of which the S segment has different origin from M and L, suggesting that reassortment might be potential force driving rapid change of SFTSV. This result might shed new light on the evolutionary behavior of the novel virus.