Novel heat shock response mechanism mediated by the initiation nucleotide of transcription.

Among SigA-dependent promoters in Bacillus subtilis, we compared the nucleotide sequences of heat shock responding and non-responding promoters. Chimeric promoter experiments revealed that the heat shock response could be ascribed to the initiation nucleotide (iNTP) of the transcription. Our in vivo reporter assay results indicated that a full response was achieved using GTP, a reduced response was observed using ATP, and no additional expression was observed using UTP or CTP. We then investigated the in vitro transcription assay in more detail. Enhanced transcription that was dependent upon the iNTP was observed when heat treatment was administered during the pre-initiation period. We next analyzed the efficiency of open complex formation using potassium permanganate footprinting, and our results revealed an increase in the ratio of open complex formation at elevated temperatures. Based on this, we suggest that the overall intensification of transcription at high temperatures was derived from the high efficiency of open complex formation together with the high affinity of RNA polymerase (RNAP) for the initiation nucleotide GTP. To determine if this mechanism observed in B. subtilis RNAP is common among bacterial species, we performed similar experiments using Escherichia coli RNAP. Our results indicated that E. coli RNAP also exhibited both temperature- and iNTP-dependent enhancement of transcription. Although the temperature ranges and the ratios of enhancement are somewhat different, the overall heat shock response mechanism mediated by the iNTP of transcription appears to be conserved among bacterial RNAP.

Repurposing a traditional Japanese method of pest control for wintering pine moths, Komo-trap, for use against summer and winter populations of fall webworms.

BACKGROUND: The fall webworm, Hyphantria cunea Drury (Lepidoptera: Erebidae), is a widespread invasive species. It is native to North America, ranging from southern Canada to northern Mexico. During and after the 1940s, this pest was accidentally introduced in many parts of Europe and Asia. It has now spread to more than 30 countries. The larvae feed on leaves of a wide range of tree species, including ones used as street trees in cities, causing an increase in urban management cost. Although several pest management methods have been employed, pest damage continues especially in newly invaded areas. In this study, we examined the effect and cost-effectiveness of the komo-trap, traditionally used in Japan to reduce the population of larvae of the pine moth Dendrolimus spectabilis Butler (Lepidoptera: Lasiocampidae). This trap, which is safe for people and ecosystems, has not yet been applied to trap the fall webworm. METHODS: In two seasons of 2017, we set komo-traps on street trees in Hakodate City, Japan. We counted the numbers of captured fall webworms compared with controls. We also monitored other species to evaluate any nontarget effects of the trap. RESULTS: One komo, the material cost of which is about 1.10 USD, captured 43.8 fall webworms on average in summer and 27.2 in the fall. The values were significantly larger than those of the controls, which were 0.07 in summer and 0.14 in winter. Bycatch of other species was minimal in summer, whereas in the fall one komo, on average, caught 10.7 woodlice Porcellio sp. or spp. (Isopoda: Porcellionidae). DISCUSSION: The komo-trap is effective in capturing fall webworm. The cost performance of the trap is very favorable, and the nontarget effects can be reduced by using the trap in summer only. The komo-trap would complement other control methods such as tree pruning. Because its cost is low, we recommend that the komo-trap be introduced as a larger-scale trial.