Termite repellent sesquiterpenoids from Callitris glaucophylla heartwood

Fractions of methanol and ethanol extracts from the heartwood of white cypress pine (Callitris glaucophylla Thompson et Johnson) were investigated for their repellent activity against subterranean termite Coptotermes formosanus Shiraki worker using a two-choice semicircular filter paper test at 0.5% (w/w) concentration. Fraction CY-E2 composed of (−)-citronellic acid, guaiol, α-, β-, and γ-eudesmol isomers as well as an unknown compound, showed the highest statistically significant repellency (97.8% ± 2.2 SEM) of all fractions tested. Bioactivity-guided fractionations using high-performance liquid chromatography led to the isolation of two, oxygenated eudesmane-type sesquiterpenes with α-methylene moieties, both termite-repellent compounds. These compounds were subsequently identified as ilicic acid methyl ester (IAME) and costic acid by means of spectroscopic analyses, electron impact mass spectrometry, and nuclear magnetic resonance spectroscopy. We report the isolation of both IAME and costic acid from C. glaucophylla heartwood for the first time. Part of this paper was presented at the 47th Symposium on the Chemistry of Terpenes, Essential Oils, and Aromatics, Tokyo, November 2003     

A chemically synthesized Antennapedia homeo domain binds to a specific DNA sequence

A peptide 60 residues in length that corresponds to the homeo domain of Antennapedia (Antp), a protein governing development in Drosophila, was synthesized by segment condensation with protected peptide segments prepared on an oxime resin. A footprinting assay showed that the homeo domain binds specifically to a TAA repeat DNA sequence in the Antp gene. Thus the Antp homeo domain has a sequence-specific DNA binding property. The circular dichroism spectra of the homeo domain peptide showed the presence of a significant amount of alpha-helical structure in aqueous solution and in 50 percent trifluoroethanol. The alpha helicity measured in water appears to depend on the peptide concentration, which suggests that the peptide aggregates. These results support the hypothesis that the homeo domain binds to DNA through a helix-turn-helix motif.     

Influence of precipitations and sunshine hours on yield of paddy field grown wheat (Triticum aestivum L.) in Northern Kyushu,Japan

ABSTRACT

Relationships between wheat (Triticum æstivum L.) yield components and growing season weather conditions (e.g. temperature, precipitation, and sunshine duration) were investigated for a rice-wheat rotation paddy system situated in Northern Kyushu, Japan over a 17-year period (2000–2016). A 1.0 mm increase in precipitation from 21 to 32 days after sowing decreased wheat yield by about 27 kg ha^?1 at early seedling stage with one to two leaves (Zadoks (Z) growth stage Z1.1–1.2). Number of tillers and spikes showed significant negative correlations to the amount of precipitation during the period. An hour increase in mean daily sunshine hours from 94 to 111 days after sowing resulted in an 328 kg ha^?1 rise in grain yield at stem elongation stage with the first and second node detection (Z3.1–3.2). The grain number per square meter also showed strong positive correlations to sunshine hours during the same period. However, this positive effect of sunshine was negated when precipitation exceeded about 30 mm during the early seedling stage. Consequently, precipitations at early seedling stage and sunshine hours at stem elongation stage mostly determined wheat yield in Northern Kyushu paddy field. Increasing precipitations during the early seedling stage highlights the pressing need for effective paddy field drainage management from wheat sowing through harvest.

Abbreviations: CP: Chikushi Plains; FARC: Fukuoka prefectural Agriculture and Forestry Research Center; SARC: Saga prefectural Agricultural Research Center; DAS: days after sowing     

Age and growth of three marine sculpins,Myoxocephalus jaok,Enophrys diceraus,and Gymnocanthus herzensteini,and age composition of fishery-bycatch sculpins in the western coastal Pacific around Hokkaido Island,Japan

Fisheries Science - The present study established an age determination technique and analyzed growth patterns in three sculpins, Myoxocephalus jaok, Enophrys diceraus, and Gymnocanthus...     

Composites of wood and trans-1,4-isoprene rubber II: Processing conditions for production of the composites

 The occurrence of grafting between WF and MTIR through esterification, the processing conditions for production of the composites, and the effect of MAH concentration on some physical and mechanical properties as well as the biodegradability of the composites have been studied. The FTIR measurement demonstrated that grafting through esterification had been attained between OH-groups of WF and acid anhydride groups of MTIR during kneading. The optimum kneading conditions for preparing the composites were 120 °C, 30 ∼ 90 rpm for 10 min. The tensile properties of the composites with WF based filler are greater than those with CS (corn starch) based filler. Addition of 10% of MTIR•10 and 8% MAH prepared using the two-step and one-step process, respectively to the TIR-WF composites gave the best result of tensile properties. The presence of MAH in the TIR-WF composites also improved the dimensional stabilization of the resulting composites. The tensile strengh of the composites prepared using the one-step process was about 90% of the composite prepared using the two-step process. The composites of TIR-WF with MTIR compatibilizer had slightly less resistance against subterranean termite (C. formasanus), brown-rot fungus (T. palustris), and white-rot fungus (C. versicolor) and slightly more resistance against bacteria (Bacillus sp.), within the experimental conditioned adopted. Received 8 February 1999     

Peptide and protein synthesis by segment synthesis-condensation

The chemical synthesis of biologically active peptides and polypeptides can be achieved by using a convergent strategy of condensing protected peptide segments to form the desired molecule. An oxime support increases the ease with which intermediate protected peptides can be synthesized and makes this approach useful for the synthesis of peptides in which secondary structural elements have been redesigned. The extension of these methods to large peptides and proteins, for which folding of secondary structures into functional tertiary structures is critical, is discussed. Models of apolipoproteins, the homeo domain from the developmental protein encoded by the Antennapedia gene of Drosophila, a part of the Cro repressor, and the enzyme ribonuclease T1 and a structural analog have been synthesized with this method.     

The establishment of microorganisms in vesicular-arbuscular mycorrhizal and control treatments

Summary We examined methods for the introduction and establishment of microorganisms in soils treated with inocula commonly used in research with vesicular-arbuscular mycorrhizal (VAM) fungi. Our purpose was to test the assumption that similar microbial groups become established in VAM fungal and control treatments. Microbial activity (CO₂ evolution) and/or the populations of protein-, chitin-, and cellulose-decomposing organisms, fluorescentPseudomonas spp., and total. fungi, bacteria, and protozoa were quantified. In closed, nonplanted systems, the establishment of microbial groups in soil, and their populations, was influenced by the type of inoculum used. In open, planted pots, the type of inoculum used affected microbial populations, shoot dry weight, and shoot and root P content, but did not affect root dry weight or shoot and root N content. We conclude that similar functional groups of microorganisms can establish in VAM and control treatments if a VAM-fungal inoculum wash is applied to both treatments. Inoculum prepared from a non VAM plant does not provide an adequate control treatment.     

Dynamics of dissolved silicon in rice paddies under conditions of water conservation irrigation

Journal of Soils and Sediments - For conserving irrigation water for rice (Oryza sativa L.) cultivation, the repeated draining/flooding with minimal amounts of water (water conservative irrigation...     

Relationships between soil aggregation and mycorrhizae as influenced by soil biota and nitrogen nutrition

 The effect of the form of N nutrition on soil stability is an important consideration for the management of sustainable agricultural systems. We grew soybean [Glycine max (L.) Merr.] plants in pot cultures in unsterilized soil, and treated them by (1) inoculating them with Bradyrhizobium japonicum, fertilizing with (2) nitrate or (3) ammonia, or (4) by providing only minimum N amendment for the controls. The soils were sampled at 3-week intervals to determine changes in water-stable soil aggregates (WSA), soil pH, the development of roots, arbuscular mycorrhizal (AM) soil and root colonization, and selected functional groups of soil bacteria. The soil fauna was assayed at the end of the experiment (9 weeks). WSA was correlated positively with root and AM soil mycelium development, but negatively with total bacterial counts. Soil arthropod (Collembola) numbers were negatively correlated with AM hyphal length. Soils of nodulated and ammonia-fertilized plants had the highest levels of WSA and the lowest pH at week 9. Sparse root development in the soils of the N-deficient, control plants indicated that WSA formation was primarily influenced by AM hyphae. The ratio of bacterial counts in the water-stable versus water-unstable soil fractions increased for the first 6 weeks and then declined, while counts of anaerobic bacteria increased with increasing WSA. The numbers of soil invertebrates (nematodes) and protozoans did not correlate with bacterial counts or AM soil-hyphal lengths. Soil pH did not affect mycorrhiza development, but actinomycete counts declined with decreasing soil pH. AM fungi and roots interacted as the factors that affect soil aggregation, regardless of N nutrition. Received: 20 December 1997     

Potential application of simple easy-to-use insertion-deletion (InDel) markers in citrus cultivar identification

We previously developed insertion-deletion (InDel) markers that distinguish three genotypes (two homozygous and one heterozygous) of diverse citrus cultivars. These InDel markers were codominant and could be clearly detected by using simple agarose gel electrophoresis. We sought to establish a method for cultivar identification using these 28 InDel markers to genotype 31 citrus cultivars. The results revealed that a minimum of 6 markers were required to identify individuals using the three-genotype classification method. Furthermore, we found that a simple method for distinguishing between two genotypes (homozygous and heterozygous) could be used to identify individuals using a minimum of 7 markers. Our findings provide a basis for the development of simple and rapid citrus cultivar identification methods.