A recent breakthrough in agricultural biotechnology is the introduction of RNAi-mediated strategies in pest control.  However, the off-target effects of RNAi pest control are still not fully understood.  Here, we studied the off-target effects of two insecticidal siRNAs in both target and non-target insects.  The results revealed that off-target effects of insecticidal siRNAs occur widely in both target and non-target insects.  We classified the expression-changed genes according to their homology to the siRNA-targeted gene, related KEGG pathways with the siRNA-targeted gene and continuous matches with siRNAs.  Surprisingly, the unintended significant changes in gene expression levels did not strictly match with the number of contiguous nucleotides in the siRNAs.  As expected, the expression of small portions of the homologous and KEGG-related genes were significantly changed.  We calculated the Shannon entropy of the transcriptome profile of the insects after injecting them with insecticidal siRNAs.  Though hundreds of genes were affected in their expression levels post siRNA-treatment, the Shannon entropy of the transcriptome remained unchanged, suggesting that the transcriptome expression was balanced.  Our results provide evidence that siRNAs cross-reacted with individual genes in non-target species, but did not have significant effects on the integrity of the transcriptome profiles in either target or non-target species on a genomic scale.  The metric we proposed can be used to estimate the off-target effects of insecticidal siRNAs, which might be useful for evaluating the safety of RNAi in pest control.  

Phosphorus (P) is an important macronutrient for plant but can also cause potential environmental risk. In this paper, we studied the long-term fertilizer experiment (started 1980) to assess the soil P dynamic, balance, critical P value and the crop yield response in Taihu Lake region, China. To avoid the effect of nitrogen (N) and potassium (K), only the following treatments were chosen for subsequent discussion, including: C0 (control treatment without any fertilizer or organic manure), CNK treatment (mineral N and K only), CNPK (balanced fertilization with mineral N, P and K), MNK (integrated organic manure and mineral N and K), and MNPK (organic manure plus balanced fertilization). The results revealed that the response of wheat yield was more sensitive than rice, and no significant differences of crop yield had been detected among MNK, CNPK and MNPK until 2013. Dynamic and balance of soil total P (TP) and Olsen-P showed soil TP pool was enlarged significantly over consistent fertilization. However, the diminishing marginal utility of soil Olsen-P was also found, indicating that high-level P application in the present condition could not increase soil Olsen-P contents anymore. Linear-linear and Mitscherlich models were used to estimate the critical value of Olsen-P for crops. The average critical P value for rice and wheat was 3.40 and 4.08 mg kg–1, respectively. The smaller critical P value than in uplands indicated a stronger ability of P supply for crops in this paddy soil. We concluded that no more mineral P should be applied in rice-wheat system in Taihu Lake region if soil Olsen-P is higher than the critical P value. The agricultural technique and management referring to activate the plant-available P pool are also considerable, such as integrated use of low-P organic manure with mineral N and K.

Porcine deltacoronavirus (PDCoV) is a newly found pathogen that could potentially cross-species transmit to threat the safety of swine and human. The mechanism of PDCoV nonstructural protein 14 (nsp14) inhibits the expression of IFN-β is unknown. In this study, we showed that PDCoV nsp14 degrades MAVS, MyD88 and TRAF3 protein in host cells by proteasomal and autophagy pathway. PDCoV nsp14 recruites E3 ubiquitin ligase MARCH8 for catalyzing MAVS, MyD88 and TRAF3 protein ubiquitination, and which were recognized and transported to lysosome by the cargo receptor NDP52 for degradation to inhibit the expression of IFN-β. Furthermore, we found that MAVS, MyD88 and TRAF3 also degrade PDCoV nsp14 by selective autophagy. These results reveal the dual function of selective autophagy in PDCoV nsp14 and host proteins, which could promote the ubiquitination of viral particles and host antiviral proteins to degrade both of the proteins for regulating the relationship between virus infection and host innate immunity.