Benzpyrimoxan: Design,synthesis, and biological activity of a novel insecticide

Benzpyrimoxan (5-(1,3-dioxan-2-yl)-4-{[4-(trifluoromethyl)phenyl]methoxy}pyrimidine, NNI-1501) was discovered as a novel insecticide structurally characterized by a pyrimidine derivative substituted with 1,3-dioxanyl and 4-trifluoromethylbenzyloxy groups. The compound showed remarkable activity against nymphs of rice planthoppers, including strains resistant to existing insecticides. Furthermore, benzpyrimoxan had low adverse effects on pollinators and beneficial arthropods. Because of these features, benzpyrimoxan is expected to be a suitable part of an integrated pest management strategy. In this report, the history of the discovery to reach benzpyrimoxan and details of the structure–activity relationships are described.     

Engineering of a tyrosol-producing pathway, utilizing simple sugar and the central metabolic tyrosine, in Escherichia coli

Metabolic engineering was applied to the development of Escherichia coli capable of synthesizing tyrosol (2-(4-hydroxyphenyl)ethanol), an attractive phenolic compound with great industrial value, from glucose, a renewable carbon source. In this strain, tyrosine, which was supplied not only from the culture medium but also from the central metabolism, was converted into tyrosol via three steps: decarboxylation, amine oxidation, and reduction. The engineered strain synthesized both tyrosol and 4-hydroxyphenylacetate (4HPA), but disruption of the endogenous phenylacetaldehyde dehydrogenase gene shut off 4HPA production and improved the production of tyrosol as a sole product. The engineered mutant strain was capable of producing 0.5 mM tyrosol from 1% (w/v) glucose during a 48 h shake flask cultivation.     

Species-specific insecticide resistance to imidacloprid and fipronil in the rice planthoppers Nilaparvata lugens and Sogatella furcifera in East and South-east Asia

BACKGROUND: In 2003 the development of insecticide resistance against neonicotinoids in the brown planthopper (BPH), Nilaparvata lugens (Stål) (Homoptera: Delphacidae), was first observed in Thailand and has since been found in other Asian countries such as Vietnam, China and Japan. However, the LD₅₀ values of BPH and the whitebacked planthopper (WBPH), Sogatella furcifera (Horváth), against both neonicotinoid and phenylpyrazole insecticides have been poorly reported in many Asian countries. RESULTS: The topical LD₅₀ values for imidacloprid in the BPH populations collected from East Asia (Japan, China, Taiwan) and Vietnam in 2006 were 4.3–24.2 µg g^?1 and were significantly higher than those collected from the Philippines (0.18–0.35 µg g^?1). The BPH populations indicated a positive cross‐resistance between imidacloprid and thiamethoxam. Almost all the WBPH populations from Japan, Taiwan, China, Vietnam and the Philippines had extremely large LD₅₀ values (19.7–239 µg g^?1 or more) for fipronil, except for several populations from the Philippines and China. CONCLUSION: Species‐specific changes in insecticide susceptibility were found in Asian rice planthoppers (i.e. BPH for imidacloprid and WBPH for fipronil). Insecticide resistance in BPH against imidacloprid occurred in East Asia and Indochina, but not in the Philippines. In contrast, insecticide resistance in WBPH against fipronil occurred widely in East and South‐east Asia. Copyright © 2008 Society of Chemical Industry     

Transgenic modification of the n‐3 HUFA biosynthetic pathway in nibe croaker larvae: improved DPA (docosapentaenoic acid; 22:5n‐3) production

Marine fish are generally unable to produce sufficient quantities of n‐3 highly unsaturated fatty acid (n‐3 HUFA) such as eicosapentaenoic acid (EPA; 20:5n‐3) and docosahexaenoic acid (DHA; 22:6n‐3). Consequently, the seed production of marine fish requires careful nutritional enrichment of live feeds such as rotifers and brine shrimp Artemia to meet n‐3 HUFA requirements for normal growth. Another strategy for improving n‐3 HUFA availability is modifying the biosynthetic pathway of marine fish using transgenic technology. In this study, we conducted a feeding trial with non‐transgenic and transgenic nibe croaker Nibea mitsukurii carrying the elongation of very long‐chain fatty acids protein 2 (Elovl2) gene isolated from masu salmon Oncorhynchus masou and three groups of Artemia (non‐enriched and enriched with two products). For all Artemia groups, docosapentaenoic acid (DPA, 22:5n‐3), which is a direct product of Elovl2, was significantly higher in the transgenic fish than that in non‐transgenic fish, despite the absence of DPA in all diets. Thus, applying transgenic techniques to marine fish at the larval stage are a powerful strategy for modifying n‐3 HUFA biosynthetic pathways.     

Development of EST-SSR markers and construction of a linkage map in faba bean (Vicia faba)

To develop a high density linkage map in faba bean, a total of 1,363 FBES (Faba bean expressed sequence tag [EST]-derived simple sequence repeat [SSR]) markers were designed based on 5,090 non-redundant ESTs developed in this study. A total of 109 plants of a ‘Nubaria 2’ × ‘Misr 3’ F₂ mapping population were used for map construction. Because the parents were not pure homozygous lines, the 109 F₂ plants were divided into three subpopulations according to the original F₁ plants. Linkage groups (LGs) generated in each subpopulation were integrated by commonly mapped markers. The integrated ‘Nubaria 2’ × ‘Misr 3’ map consisted of six LGs, representing a total length of 684.7 cM, with 552 loci. Of the mapped loci, 47% were generated from multi-loci diagnostic (MLD) markers. Alignment of homologous sequence pairs along each linkage group revealed obvious syntenic relationships between LGs in faba bean and the genomes of two model legumes, Lotus japonicus and Medicago truncatula. In a polymorphic analysis with ten Egyptian faba bean varieties, 78.9% (384/487) of the FBES markers showed polymorphisms. Along with the EST-SSR markers, the dense map developed in this study is expected to accelerate marker assisted breeding in faba bean.     

A comparative analysis of two paddy irrigation schemes under contrasting water management of participatory and top-down systems in Uganda

Paddy and Water Environment - This research focused on two large-scale paddy irrigation schemes of Doho (1000 ha) and Lwoba (700 ha) in Uganda for a comparative analysis of major...     

Periodic changes in the growth performance and biochemical composition of juvenile red sea bream <Emphasis Type="Italic">Pagrus major</Emphasis> fed non-heated and heated squid and krill meal-based diets

In finfish aquaculture, fish meal is heated during the manufacturing process, which affects the digestibility and protein absorption by fish. However, manufactured fishmeal that is not heated does not undergo thermal denaturation. Few studies have investigated the effects of non-heated animal protein sources on the growth performance of fish. We investigated the effects of heated and non-heated squid and krill meal as diets for red sea bream. Five test diets were formulated to contain heated squid meal, non-heated squid meal, heated krill meal, non-heated krill meal, and fish meal as a control. Fifty fish (initial mean weight?=?3.5 g) were distributed in ten 100-l experimental tanks. Fish were fed one of the five diets 3 times daily until satiation for 5 weeks. Regarding growth performance, fish fed the krill meal diet exhibited better growth than those fed squid meal during the first week of the rearing period. However, the squid meal diet group showed better performance than the krill meal diet group during the third week. Moreover, differences in body weight among treatments were greater during the fifth week. Better weight gain and thermal growth coefficient were recorded in the non-heated diet groups than in the heated diet groups. Higher feed intake was observed in the non-heated diet groups than in the heated diet groups. These results suggest higher performance of non-heated squid and krill meal as the protein source of the red sea bream diet. Further, the suitability of the diet type (e.g., squid and krill) might depend on the feeding period and/or developmental stage of fish.     

A method for estimating radioactive cesium concentrations in cattle blood using urine samples

In the region contaminated by the Fukushima nuclear accident, radioactive contamination of live cattle should be checked before slaughter. In this study, we establish a precise method for estimating radioactive cesium concentrations in cattle blood using urine samples. Blood and urine samples were collected from a total of 71 cattle on two farms in the ‘difficult‐to‐return zone’. Urine ¹³⁷Cs, specific gravity, electrical conductivity, pH , sodium, potassium, calcium, and creatinine were measured and various estimation methods for blood ¹³⁷Cs were tested. The average error rate of the estimation was 54.2% without correction. Correcting for urine creatinine, specific gravity, electrical conductivity, or potassium improved the precision of the estimation. Correcting for specific gravity using the following formula gave the most precise estimate (average error rate = 16.9%): [blood ¹³⁷Cs] = [urinary ¹³⁷Cs]/([specific gravity] ? 1)/329. Urine samples are faster to measure than blood samples because urine can be obtained in larger quantities and has a higher ¹³⁷Cs concentration than blood. These advantages of urine and the estimation precision demonstrated in our study, indicate that estimation of blood ¹³⁷Cs using urine samples is a practical means of monitoring radioactive contamination in live cattle.     

Ploidy variation of hardy kiwifruit (Actinidia arguta) resources and geographic distribution in Japan

Survey on the wild genetic resources of hardy kiwifruit (Actinidia arguta) in Japan was conducted to determine the ploidy variation and its geographic distribution. Among the 127 wild plants collected from different geographic locations, 15 plants were diploid, 87 were tetraploid, and 22 were hexaploid. Additionally, 2 plants were heptaploid and one plant was octaploid. The tetraploid plants were distributed all over the country, whereas the diploid and hexaploid plants were geographically localized, in the warm Pacific hill areas of the south western part and in the deep-snow region of the mid-northern part of Honshu, respectively. The diploid plants could be clearly distinguished from other plants with ploidy variation by the morphological characteristics of the leaf and fruit. Hexaploid plants showed a relatively larger L/D ratio of the leaf blade, a greenish petiole, and pubescence on the petiole and lower leaf vein, whereas the tetraploid plants exhibited a reddish petiole and callose hairs on the vein of the lower leaf surface. Fruit shape of the tetraploid plants varied largely, from round to ellipsoidal, whereas that of the hexaploid plants was mostly ellipsoidal. These results indicate that the hexaploid plants of A. arguta as well as the diploid and tetraploid ones, naturally grow in a certain size of population in the restricted region of Japan.