Effect of Inorganic Phosphate on the Levels of Amino Acids in Suspension-cultured Cells of Catharanthus roseus

The levels of free amino acids in suspension cultures of Catharanthusroseus were monitored for 96 h after stationary-phase cellswere transferred to fresh complete (‘+Pi’)     

Development and diversity of microsatellite markers for endangered species,Morus boninensis Koidz., to establish conservation program

We have developed seven microsatellite markers from an enrichment library of genomic DNA for an endangered species, Morus boninensis. A total of 112 of the 320 clones were found to have unique sequences with microsatellite repeats. Seven of 54 primer pairs revealed clear chromatograms and polymorphisms among 36 individuals sampled from three of the Bonin Islands. Seven to 17 alleles per locus were detected, and the expected heterozygosity without considering double reduction ranged from 0.429 to 0.819. These findings should be useful for those studying the conservation genetics of M. boninensis.     

PURIFICATION OF GONAD-STIMULATING SUBSTANCE OBTAINED FROM RADIAL NERVES OF THE STARFISH, ASTERIAS AMURENSIS

Purification of starfish gonad-stimulating substance (GSS), which induces shedding of gametes and oocyte maturation, was carried out using lyophilized radial nerves of Asterias amurensis as source material. In the first series of experiments, 1.3 mg of the purified GSS, which induced spawning at a concentration of 0.0096 μg/ml, was isolated from acetone powder of lyophilized radial nerves of 7,360 starfish through several steps of purification procedures consisting of gel-filtrations on Sephadex G–50 and G–25 columns of various sizes and ion-exchange chromatography on DEAE-Sephadex columns by gradient as well as step-wise elution. With this sample, the molecular weight and amino acid composition of GSS were estimated. Another series of experiments, conducted on a similar amount of material with purification procedures which were essentially the same as those of the first series except for employing 2 steps of partition chromatography instead of extensive gel-filtration, gave about 0.1 mg of purified sample which served as material for studies of the amino acid composition and electrophoretic properties of GSS.
The molecular weight of Asterias GSS was found to be about 2,100, as determined with the sedimentation equilibrium method. GSS seemed to consist of the following 22 amino acid residues: aspartic acid (2), threonine (1), serine (6), glutamic acid (1), proline (1), glycine (4), alanine (2), valine (1), isoleucine (1), leucine (1), histidine (1), and ornithine (1). The isoelectric point of GSS was found to be at about pH 4.5 as determined by the isoelectric focusing method.     

Effects of selected insecticides on Diadegma semiclausum（Hymenoptera： Ichneumonidae） and Oomyzus sokolowskii （Hymenoptera： Eulophidae）, parasitoids of Plutella xylostella （Lepidoptera： Plutellidae）

Abstract Field doses of six selected insecticides were tested against the immature (pupae) and mature (adult) stages of Diadegma semiclausum (Hellén) and Oomyzus sokolowskii (Kurdjumov), parasitoids of the diamondback moth, Plutella xylostella (L.). Effects of contact toxicity (direct spraying) of the six insecticides on emergence of parasitoids were found negligible on both species except permethrin which caused 37.5% mortality. All adults of both parasitoid species died 24 hours after exposure to chlorfenapyr, emamectin benzoate and permethrin. In contrast, the three insect growth regulators (IGRs), chlorfluazuron, flufenoxuron and teflubenzuron, were found harmless to both species, and adult mortality of both parasitoid species was 0–16.7%. However, parasitism by the females of both parasitoid species was severely impaired when the females were offered the three IGR diluted solutions for 24 hours. Effects of oral toxicities of the IGRs on longevity of both parasitoids after 12 hours exposure were found to be significantly different between males and females. Compatibility of tested insecticides with D. semiclausum and O. sokolowskii and integration of compatible insecticides with these parasitoids in integrated pest management programs of crucifers are discussed.     

A revision of the genus Trixa Meigen （Diptera： Tachinidae）

The genus Trixa Meigen, 1824 is revised. Dexiotrix Villeneuve, 1936 and Trixella Mesnil, 1980, each of which was sometimes treated as a distinct genus, are treated as junior synonyms of Trixa Meigen. Two species from Sichuan and Yunnan, China, are described as new to science, viz. Trixa chinensis sp. nov. and T. chaoi sp. nov. T. alpina Meigen is treated as a junior synonym of T. caerulescens Meigen. T. nox (Shima) and T.pubiseta (Mesnil) are newly recorded from China. Males of T. pubiseta (Mesnil) and T.longipensis (Villeneuve) are described for the first time. Diagnoses, figures and a key to twelve species in Trixa are given.     

Mode of pollen tube growth in pistils of Ticodendron incognitum (Ticodendraceae,Fagales) and the evolution of chalazogamy

Ticodendron incognitum is the sole species of the Ticodendraceae, which was established as a new family in the Fagales less than 20 years ago. Considering the diverse modes of pollen tube growth observed in other Fagales, we investigated the growth of pollen tubes in the pistil of Ticodendron. At the time of pollination, T. incognitum had four immature ovules in a bilocular ovary, thus exhibiting delayed fertilization, as in other Fagales. During the period when fertilization was delayed, pollen tube growth in the pistil was intermittent, consisting of five steps associated with development of the ovules and embryo sacs. Four cessation sites occurred: in the style, in the tissue of the upper part of the ovary, inside and outside of the funicle and at the chalaza. A single pollen tube eventually reaches a mature embryo sac through the chalaza in one of the four ovules. While both delayed fertilization and intermittent pollen tube growth play a role in male and female gametophyte selection, as in other Fagales, the five‐step process of pollen tube growth through the chalaza (i.e. chalazogamy) is characteristic of lineages of the Casuarinaceae, Ticodendraceae and Betulaceae (the latter with the loss of one step). © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 621–631.     

Tissue Distribution of an Immunogenic Melanoma Associated Antigen,D-1

A human melanoma-associated antigen immunogenic in patients was recently identified by screening an expression cDNA library constructed from cultured human melanoma cell line with sera from patients with melanoma. The nucleic acid sequence of the cloned D-1 cDNA has no significant homology with previously reported mammalian genes. The cDNA D-1 encodes a peptide of about 37 kDa, which showed fivefold higher reactivity with sera from patients with melanoma than with sera from normal donors. In order to detect D-1 gene expression in vivo, in-situ hybridization and immunostaining with cRNA probe and murine anti-D-1 sera were carried out on surgically removed tissues. Digoxigenin-labeled cRNA D-1 was exclusively hybridized with mRNA in the cytoplasm of melanoma cells but not with keratinocytes and fibroblasts adjacent to melanoma nests. Polyclonal anti-D-1 antibodies were obtained by immunization of Balb/c mice with recombinant D-1 peptide and clearly reacted with melanoma cells but not with keratinocytes and fibroblasts, similar to the results of in-situ hybridization. The above information will help to assess the suitability of recombinant D-1 peptide to implement active specific immunotherapy in patients with melanoma.     

EFFECTS OF CULTURE CONDITIONS ON HYDROGENASE ACTIVITY OF SCENEDESMUS D3

The effects of culture conditions and of culture ages upon hydrogenaseactivity in Scenedesmus D₃ was investigated with nitrite andbenzoquinone as acceptors. It was noticed that level of ironin the culture medium played an important part in the developmentof hydrogenase activity. The cells grown on a medium of relatively high level of iron(10^–4 M) showed higher activity both in nitrite and benzoquinonereduction than those grown on a medium of relatively low levelof iron (10^–5 M). In the former case, hydrogenase activityappeared even after a short incubation with hydrogen (30 min). When the cells with low hydrogenase activity were transferredto a medium containing 10^–;4 M iron and the activity wasmeasured every 24 hours, the following facts were observed. (a) Nitrite reduction activity increased markedly during thefirst 24 hours and then decreased gradually during further cultivation.Furthermore, a parallelism was observed between nitrite reductionactivity and cell size. (b) On the other hand, the pattern of change in quinone reductionactivity was somewhat different from that of nitrite reduction.This activity appeared only after 3 days' cultivation, reacheda maximum at 4th or 5th day and then decreased. However, thepresence of glucose in the culture medium suppresses the appearanceof quinone reduction activity, while the nitrite reduction activitywas less markedly affected. ¹Present address: Department of Experimental Radiology, Facultyof Medicine, Kyushu University, Fukuoka.     

ROLE OF CALCIUM IN POTASSIUM UPTAKE BY PLANT ROOTS

The effects of EDTA·Mg or GEDTA·Mg on the uptakeof nutrient ions, the release of Ca⁺⁺ and nucleotides into themedium and the nucleic acid contents in rice and red bean rootswere investigated.

1. Both EDTA and EDTA·Mg induced similarly the release ofCa from roots.
2. EDTA·Mg as well as EDTA brought abouta significant repressionin K uptake, but had an insignificantor no effect on P, NH₄and NO₃ uptakes. EDTA·Ca did notrepress K, P, NH₄ andNO₃ uptakes.
3. EDTA or GEDTA acceleratedthe degradation of nucleic acid andthe release of nucleotides,while EDTA·Mg or GEDTA·Mghad no such effect.

These results indicate that the indispensable role of intracellularCa in K uptake does not appear to be directly associated withRNA metabolism. (Received July 29, 1965; )     

Respiratory Utilization of 13C-Labelled Photosynthate in Nodulated Root Systems of Soybean Plants

Kouchi, H., Akao, S. and Yoneyama, T. 1986. Respiratory utilizationof ¹³C-labelled photosynthate in nodulated root systems of soybeanplants.—J. exp. Bot. 37: 985–993. An improved method for the measurement of respiratory utilizationof current photosynthate in the nodulated root system of water-culturedsoybean (Glycine max L.) plants was developed using a steady-state¹³CO₂ labelling technique. Well-nodulated plants at the latevegetative stage were allowed to assimilate ¹³CO₂ for 10 h incontinuous light at a constant CO₂ concentration with a constant¹³C abundance. The respiratory evolution of ¹³CO₂ from rootsand nodules was measured continuously throughout the periodof ¹³CO₂ assimilation and during a subsequent 36 h chase periodby using a differential infrared ¹³CO₂ analyser. The plantswere grown with nitrogen-free or (15 mmol dm^–3)-containing culture solution for 3 d before¹³CO₂ assimilation. In plants grown without , nodule respiration averaged 69% of the total respiration of the undergroundparts over the full experimental period and the CO₂ respiredreached an apparent isotopic equilibrium at 80–85% labellingafter initiating ¹³CO₂ assimilation. By contrast, the CO₂ respiredfrom the roots did not reach an isotopic equilibrium and labellingwas only 56% at the end of exposure to ¹³CO₂ These findingsdemonstrated that nodule respiration is strongly dependent onrecently assimilated carbon compared with root respiration. Plants supplied with in the culture solution showed a decreased rate of nodule respirationand a slightly increased rate of root respiration. The extentsand time courses of labelling of respired CO₂ from both theroots and nodules were similar in the presence and absence of except that the maximum level of labelling of CO₂ derived from nodule respiration in plantswith was significantly higher (about 91%) than for plants growing without . Key words: Soybean (Glycine max L.), nodule respiration, ¹³CO₂, assimilation, carbon partitioning