RNAi介导的有害生物防控策略是农业生物技术领域的最新突破之一。但是，目前对RNAi防控策略可能产生的脱靶效应仍未完全了解。本文中，我们研究了两种昆虫致死基因siRNA在靶标和非标靶昆虫中的脱靶效应。结果表明，致死基因siRNA的脱靶效应广泛存在于靶标昆虫和非靶标昆虫中。我们根据基因的同源性、相关KEGG途径以及与siRNA序列的连续匹配度，对所有表达量受影响的基因进行了分类。出人意料的是，非靶标基因表达量受影响的程度与序列的连续匹配度并不一直。而少部分同源基因和KEGG相关基因的表达量正如预期的一样发生了显著变化。通过计算转录组熵值，结果表明尽管在siRNA处理后数百个基因的表达受到影响，但转录组的熵值保持不变，这表明转录组的表达模式在整体上是平衡的。本文的结果表明，siRNA与非靶标生物中的单个基因发生交叉反应，但在基因组水平上对靶标和非靶标生物中转录组完整性并没有显着影响。同时，本文提出了一种评估昆虫致死基因siRNA脱靶效应的体系，将有助于评估RNAi害虫防控策略的安全性。

The striped stem borer (SSB), Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), is a major pest of rice in China. Variation in host-plant quality may affect the body size of herbivorous insects, which in turn, can determine their lifehistory parameters such as survival, fecundity and fitness. In this study, we tested the effects of high-quality aromatic rice varieties on the fitness of SSB in China. Results showed that 1st instar larvae had higher penetrating rates and survival rates on the high-quality aromatic rice varieties (EX-1 and WX-988) than that on the non-aromatic rice varieties (EZ-5 and LYP-9). In addition, shorter developmental periods, greater female pupal weights and higher of other life-history parameters (hatching rate, pupation rate, eclosion rate and increase index) were found on the high-quality aromatic rice varieties, although only female pupal weight showed a significant difference between the two varieties. The highest dead heart rate was found on the aromatic rice variety of EX-1. These results indicate that SSB sustains a lower fitness cost when consuming the high-quality aromatic rice varieties (EX-1 and WX-988) than on the non-aromatic rice varieties (EZ-5 and LYP-9) in Central China.

The polyphagous B-biotype of Bemisia tabaci (Gennadius) has demonstrated a high capacity to adapt to numerous hosts from diverse plant families. To illustrate induced responses by the host plant, biochemical research on eight plant-insect interaction correlative enzymes, representing detoxifying, antioxidant and digestive pathways, were investigated. Transferring whitefly adults to Zhongmian 23 from the pre-adapted host Zhongmian 41 induced activities of carboxylesterase (by 1.80-fold), glutathione S-transferase (by 3.79-fold), proteinase (by 1.62-fold) and amylase (by 2.41-fold) activities, but decreased polyphenol oxidase (by 1.89-fold) and peroxidase (by 1.88-fold). However, transferring whitefly adults to the favorite host abutilon from Zhongmian 41 was associated with increased activities of cytochrome P450 monooxygenase (by 1.61-fold) and amylase (by 1.42-fold), and decreased activities of polyphenol oxidase (by 2.96-fold) and peroxidase (by 2.07-fold). Our results, together with previous studies, proved that multiple pathways are involved in coping with host shifts by polyphagous herbivores, and the taxonomic status and preference of the host transferred would affect which pathway would be induced. These results would represent a key challenge in developing long-term sustainable insect control strategies.

Transgenic Bt rice has been shown to be an effective means of controlling Lepidoptera pests of rice. However, the potential roles of transgenic rice on planthoppers and their predators need to be investigated before its commercialization. Population density, species dominance and population dynamics are important parameters of arthropods populations in field. So the impacts of three transgenic Bt rice strains expressing cry1Ab/cry1Ac, cry1C and cry2A on population density, species dominance and population dynamics of three species of planthoppers (Nilaparvata lugens, Sogatella furcifera and Laodelphax striatellus) and their three main predators (Cyrtorhinus lividipennis, Pirata subpiraticus and Theridium octomaculatum) were evaluated at three sites in Hubei Province, China, in the current study. The results showed that among three species of planthoppers, both in transgenic and non-transgenic rice field, the predominant species of planthoppers within phytophagous guild was S. furcifera at any site either growing season (46-50%). Significantly higher population density of N. lugens was observed in T2A-1 field relative to Minghui 63 field at Wuxue in 2010. The species dominance of predator, P. subpiraticus, in TT51 field was significantly higher than that in T1C-19 and T2A-1 fields in 2009 at Xiaogan site. Sampling date significantly influenced six arthropods except for P. subpiraticus in 2010. The interaction between rice strain×sampling date had no significant adverse effects on the population dynamics of three species of planthoppers and their predators, except for several individual species in 2009. The interaction among rice strain×sampling date×sampling site also had no significant effect on six arthropods except for S. furcifera in 2009. The results indicated that transgenic Bt rice expressing cry1Ab/cry1Ac, cry2A and cry1C had no significant adverse effects on the population dynamics of three planthoppers and their predators in most investigated data and sampling site.