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MicroRNAs (miRNAs), are a novel class of gene expression regulators, that have been found to participate in regulating host–virus interactions. However, the function of insect-derived miRNAs in response to virus infection is poorly understood. We analyzed miRNA expression profiles in the fat bodies of Helicoverpa armigera (H. armigera) infected with Mamestra brassicae multiple nucleopolyhedroviruses (MbMNPV). A total of 52 differentially expressed miRNAs (DEmiRNAs) were filtered out through RNA-seq analysis. The targets of 52 DEmiRNAs were predicted and 100 miRNA–mRNA interaction pairs were obtained. The predicted targets of DEmiRNAs were mainly enriched in the Wnt signaling pathway, phagosome, and mTOR signaling pathway, which are related to the virus infection. Real-time PCR was used to verify the RNA sequencing results. ame-miR-317-3p, mse-miR-34, novel1-star, and sfr-miR-6094-5p were shown to be involved in the host response to MbMNPV infection. Results suggest that sfr-miR-6094-5p can negatively regulate the expression of four host genes eIF3-S7, CG7583, CG16901, and btf314, and inhibited MbMNPV infection significantly. Further studies showed that RNAi-mediated knockdown of eIF3-S7 inhibited the MbMNPV infection. These findings suggest that sfr-miR-6094-5p inhibits MbMNPV infection by negatively regulating the expression of eIF3-S7. This study provides new insights into MbMNPV and H. armigera interaction mechanisms. [ABSTRACT FROM AUTHOR]

Due to the increasingly intensive anthropogenic disturbance, soils are susceptible to the pollution by heavy metals, with Pb pollution becoming one of the most severe issues worldwide. It is crucial and beneficial to derive soil environmental criteria for environmental risk assessment and contaminated land management of Pb pollution in soil. In this work, the terrestrial toxicity thresholds including 10% effect concentration (EC10) or no observed effect concentration (NOEC) of Pb were collected from the ecotoxicological database and the published literature. The modeling analysis were performed using species sensitivity distribution (SSD) method according to soil pH. The soil environmental criteria for Pb were derived based on the protection levels of the different land use types. The results showed that soil quality criteria for Pb were 51.1 ~ 153 mg⋅kg-1, 172 ~ 342 mg⋅kg-1, 342 ~ 537 mg⋅kg-1 and 440 ~ 634 mg⋅kg-1 for natural reserve/agricultural land, park, residential land and industry/commercial land, respectively. This study provides the scientific basis for developing the ecological risk assessment framework and soil environmental standards for Pb in China. [ABSTRACT FROM AUTHOR]