Long-term conservation of embryogenic competence by induction and disorganization of somatic embryos in carrot

A simple procedure was established to maintain the rate of somatic embryogenesis in carrot cell strains. Secondary cell strains were induced by the disorganization of heart‐shaped somatic embryos by transferring them into a medium containing 2,4‐dichlorophenoxyacetic acid and the rate of somatic embryogenesis was restored to the original level. It was possible to keep the original rate of embryogenesis by repeated induction and disorganization of somatic embryos, as the restored rate of embryogenesis decreased gradually during subcultures. In the carrot cell suspension culture used in this work, it was possible to keep high rates of somatic embryogenesis for at least 3 years by using this method at every 50th subculture. The method presented here should be useful to maintain regeneration competence in certain important cell strains.     

Non-Linearities between Atmospheric Sulphur and Sulphur Emissions

Downing et al. (1995) and others have reported evidence fora non-linearity between atmospheric sulphur and sulphur emissionsin the U.K. Also, there are reports of the effects of the non-linearity being concentrated in regions close to sources. Here we re-analyse the same data in sulphur dioxide versus emission space. Analysis has been carried out at three sites at varying distances from the main U.K. source regions. Annual, seasonal and meteorological categorisations were made to try andclarify observation of any non-linearity. Over long timescales linearity is not excluded. Inter-annual variability is not correlated with emissions. The relation between sulphur dioxideand emissions was found to be least linear for westerly days at asite in southern Scotland. Overall, the extent of non-linearity is not observed to increase with proximity to sources but the relation is least linear for summer days at sites closer to themain source areas.     

The 1,4-naphthoquinone derivative from Pyrola rotundifolia activates AMPK phosphorylation in C2C12 myotubes

An aqueous ethanol extract of Pyrola rotundifolia L. induced AMP-activated protein kinase (AMPK) phosphorylation in C2C12 myotubes. The bioassay-guided fractionation of the extract led to the isolation a 2-methyl-7-hydroxymethyl-1,4-naphthoquinone, or a 7′-hydroxy-chimaphilin, which showed concentration-dependent AMPK phosphorylation activity at 2.5–20 μg/ml. At a concentration of 10 μg/ml (50 μM), an approximately four-fold increase in the AMPKα(Thr¹⁷²) phosphorylation level was observed. The stimulatory effect of naphthoquinone on AMPK activity was comparable to that of known compounds found in natural sources that activate the AMPK signaling pathway.     

Development of species-specific PCR techniques for the detection of tortoise herpesvirus.

Previously, a nested polymerase chain reaction (PCR) was employed with consensus degenerate primers targeting highly conserved motifs within herpesviral DNA polymerase genes to detect a newly described tortoise herpesvirus. However, nucleotide sequence information obtained from the final amplified fragment was restricted to a small region of 181 bp. In the present study, additional sequences flanking this segment were determined from a PCR product successfully amplified using a set of known degenerate primers, which covered a 692-bp region within the tortoise herpesviral DNA polymerase gene. Polymerase chain reaction primers for specific amplification of the tortoise herpesviral DNA were designed on the basis of these nucleotide sequences and successfully amplified tortoise herpesviral DNA from the tissues of tortoises that were well characterized histopathologically with herpesviral infection. The lower limit of detection was 1,000 herpesviral DNA equivalents in the presence of normal tortoise genomic DNA. Furthermore, a more sensitive and specific PCR technique for the identification of herpesviral infections in tortoises was developed employing a heminested form, which will enable the detection of latent infections or herpesvirus carriers in tortoises.     

竹炭和竹醋液的功能及其商品开发

本文阐述了竹炭的物理作用、竹醋液的抗菌功能及竹醋液在农业上的应用.可将竹炭埋在土壤中以改变地磁,调节地下的电位差,用以改善和维持人体健康,预防动植物的病虫害.通过在养殖场设置竹醋液池,预防口蹄疫,禽流感等家畜家禽类的传染病.最后介绍了竹炭和竹醋液的功能及其商品开发.     

Conversion of normal behavior to shiverer by myelin basic protein antisense cDNA in transgenic mice

Myelin basic proteins (MBPs) are coded by the single gene necessary for myelin formation in the central nervous system of the mouse. An antisense MBP mini-gene was constructed and used to determine the function of antisense DNA in transgenic mice. Several transgenic offspring of a founder transgenic mouse, AS100, were converted from the normal to mutant shiverer phenotype. Antisense MBP messenger RNA was expressed in these mice, and the endogenous MBP messenger RNA, the MBP, and the myelination in the central nervous system were reduced.     

Ent-2'-epi-Orobanchol and its acetate, as germination stimulants for Striga gesnerioides seeds isolated from cowpea and red clover

Striga gesnerioides is a root parasitic weed of economic significance to cowpea (Vigna unguiculata) crops in Western Africa. Seeds of the parasite germinate in response to cowpea root exudates. Germination stimulants for the seeds were isolated from the hydroponic culture filtrate of cowpea, and their structures were unambiguously determined as (-)-(3aR,4R,8bR,2'R)-ent-2'-epi-orobanchol and (+)-(3aR,4R,8bR,2'R)-ent-2'-epi-orobanchyl acetate, on the basis of mass, CD, and (1)H NMR spectra; optical rotatory power; and chromatographic behavior on HPLC. The alcohol was first isolated and identified from the cowpea root exudates, and the acetate may be the same compound that had been previously isolated from the exudates and designated as alectrol. Identity of the stimulants produced by cowpea to those produced by red clover (Trifolium pratense) was confirmed.     

Structural requirements of strigolactones for germination induction of Striga gesnerioides seeds

Strigolactones are highly potent germination stimulants for seeds of the parasitic weeds Striga and Orobanche spp. 4-Hydroxy-GR24 and 4-acetoxy-GR24 were prepared and their abilities to induce seed germination of Striga gesnerioides evaluated. Optically active (8bR,2'R)-isomers induced germination, although the racemic diastereomers were inactive. In contrast, the stereoisomer of GR24 with the same configuration induced negligible germination. Some stereoisomers of GR24 and its analogues acted as effective antagonists for induction of seed germination by cowpea root exudates. These results suggest that both an oxygenated substituent at C-4 and the configuration of the tricyclic lactone and the D-ring are essential structural requirements for induction of germination in S. gesnerioides seeds.