Effects of intra‐ and inter‐specific competition on fitness of sweetpotato weevil and West Indian sweetpotato weevil

The sweetpotato weevil Cylas formicarius (Fabricius) (Coleoptera: Brentidae) and West Indian sweetpotato weevil Euscepes postfasciatus (Fairmaire) (Coleoptera: Curculionidae) are major pests of sweet potato Ipomoea batatas (L.) Lam., in tropical and subtropical regions. Effects of intra‐ and inter‐specific competition on the number of progeny (fecundity), body weight and developmental time of C. formicarius and E. postfasciatus were examined in single‐ and mixed‐species treatments under laboratory conditions. Cylas formicarius tended to outcompete E. postfasciatus, whereas E. postfasciatus rather than C. formicarius tolerated higher conspecific densities. We discuss the implications of the results for pest management and resource partitioning of pestiferous weevils.     

Preparation of 8-Chloropurine Nucleosides Through the Reaction Between their C-8 Lithiated Species and p-Toluenesulfonyl Chloride

Abstract

Chlorination of purine nucleosides protected with tert-butyldimethylsilyl (TBDMS) group was examined by the reaction of the C-8 lithiated species, generated by LDA, with p-toluenesulfonyl chloride as an electrophile. This provides a new method for the preparation of 8-chloropurine nucleosides.     

A Phytotoxin,Betaenone C,and Its Related Metabolites of Phoma betae Fr

For rough quantitative analysis of genetically modified maize contents, rapid methods for measurement of the copy numbers of the cauliflower mosaic virus 35S promoter region (P35S) and MON810 construct-specific gene (MON810) using a combination of a capillary-type real-time PCR system with a plasmid DNA were established. To reduce the characteristic differences between the plasmid DNA and genomic DNA, we showed that pretreatment of the extracted genomic DNA by a combination of sonication and restriction endonuclease digestion before measurement is effective. The accuracy and reproducibility of this method for MON810 content (%) at a level of 5.0% MON810 mixed samples were within a range from 4.26 to 5.11% in the P35S copy number quantification. These methods should prove to be a useful tool to roughly quantify GM maize content.     

A Study on 5′-Nucleotides in D2O Solution by Proton Magnetic Resonance Spectroscopy

Nucleotides, 5′-AMP, 5′-GMP, 5′-UMP, 5′-CMP and 5′-TMP, in D₂O solution have been investigated by proton magnetic resonance spectroscopy. The concentration and the pD dependences of the proton chemical shifts of the nucleotides have been examined in detail. These results indicate that intermolecular association of vertical stacking of the base rings and intramolecular association between base protons and ionized phosphate group occur in solution. The effects of the temperature and lithium ion on 5′-AMP and 5′-UMP have been also investigated. The increase of temperature causes to reduce the intramolecular association for 5′-UMP and the both intra- and intermolecular association for 5′-AMP. Lithium ion reduces the intramolecular association for both 5′-AMP and 5′-UMP, and at the same time promotes the intermolecular one for the former. This can be interpreted by the ion-pair formation of lithium ion with the ionized phosphate group.     

Glutathione-dependent binding of a photoaffinity analog of agosterol A to the C-terminal half of human multidrug resistance protein

MRP1 is a 190-kDa membrane glycoprotein that confers multidrug resistance (MDR) to tumor cells. MRP1 is characterized by an N-terminal transmembrane domain (TMD(0)), which is connected to a P-glycoprotein-like core region (DeltaMRP) by a cytoplasmic linker domain zero (L(0)). It has been demonstrated that GSH plays an important role in MRP1-mediated MDR. However, the mechanism by which GSH mediates MDR and the precise roles of TMD(0) and L(0) are not known. We synthesized [(125)I]11-azidophenyl agosterol A ([(125)I]azidoAG-A), a photoaffinity analog of the MDR-reversing agent, agosterol A (AG-A), to photolabel MRP1, and found that the analog photolabeled the C-proximal molecule of MRP1 (C(932-1531)) in a manner that was GSH-dependent. The photolabeling was inhibited by anticancer agents, reversing agents and leukotriene C(4). Based on photolabeling studies in the presence and absence of GSH using membrane vesicles expressing various truncated, co-expressed, and mutated MRP1s, we found that L(0) is the site on MRP1 that interacts with GSH. This study demonstrated that GSH is required for the binding of an unconjugated agent to MRP1 and suggested that GSH interacts with L(0) of MRP1. The photoanalog of AG-A will be useful for identifying the drug binding site within MRP1, and the role of GSH in transporting substrates by MRP1.     

Light-induced changes in resistivity of spinach chloroplasts toward modification with diazonium-1,2,4-triazole

Spinach chloroplasts in the light and in the dark were treated with several reagents for protein modification to see the effect of light on their resistivity toward modification. The reagents were p-diazobenzenesulfonic acid, diazonium-1-H-tetrazole, sodium-2,4,6-trinitrobenzenesulfonate, sodium-β-naphtoquinone-4,6-disulfonate and diazonium-1,2,4-triazole. No difference in the absorption spectrum was found between chloroplasts treated with these reagents in the light and those treated in the dark. However, these light- and dark-treated samples when solubilized with a nonionic detergent showed a difference in turbidity. Diazonium-1,2,4-triazole was the most suitable of the above reagents, and the solubilized sample of chloroplasts treated with diazonium-1,2,4-triazole in the light showed a turbidity which was about 2-fold higher than that of the same sample treated in the dark. This increase in turbidity was interpreted as being due to a change in the resistivity toward chemical modification of chloroplasts caused by illumination. In the presence of 3-(p-chlorophenyl)-1,1-dimethylurea, pentachlorophenol and 2-methylthio-4,6-bis-isopropylamino-s-triazine, which are inhibitors of the Hill reaction, the light-induced increase of turbidity was suppressed by 72, 78 and 62%, respectively. The addition of ATP caused a much greater increase of turbidity both in the light and in the dark. It was thus found that light and ATP induce a configurational change of chloroplasts or a conformational change of chloroplast proteins inside.     

Molecular phylogeny of monocotyledons inferred from combined analysis of plastid<Emphasis Type="Italic"> matK</Emphasis> and<Emphasis Type="Italic"> rbcL</Emphasis> gene sequences

Using matK and rbcL sequences (3,269 bp in total) from 113 genera of 45 families, we conducted a combined analysis to contribute to the understanding of major evolutionary relationships in the monocotyledons. Trees resulting from the parsimony analysis are similar to those generated by earlier single or multiple gene analyses, but their strict consensus tree provides much better resolution of relationships among major clades. We find that Acorus (Acorales) is a sister group to the rest of the monocots, which receives 100% bootstrap support. A clade comprising Alismatales is diverged as the next branch, followed successively by Petrosaviaceae, the Dioscoreales–Pandanales clade, Liliales, Asparagales and commelinoids. All of these clades are strongly supported (with more than 90% bootstrap support). The sister-group relationship is also strongly supported between Alismatales and the remaining monocots (except for Acorus) (100%), between Petrosaviaceae and the remaining monocots (except for Acorus and Alismatales) (100%), between the clade comprising Dioscoreales and Pandanales and the clade comprising Liliales, Asparagales and commelinoids (87%), and between Liliales and the Asparagales–commelinoids clade (89%). Only the sister-group relationship between Asparagales and commelinoids is weakly supported (68%). Results also support the inclusion of Petrosaviaceae in its own order Petrosaviales, Nartheciaceae in Dioscoreales and Hanguanaceae in Commelinales.Electronic Supplementary Material Supplementary material is available in the online version of this article at http://dx.doi.org/10.1007/s10265-003-0133-3