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101.
Artificial lighting is a merit of a ‘plant factory’, which might be utilized to suppress an increase in pest population. We
investigated the effects of extending the light phase on diapause induction in the two-spotted spider mite (TSSM), Tetranychus urticae. TSSM were reared at 18°C under light phases ranging from 2 to 64 h combined with a constant dark phase of 16 h in aluminum
bottles, with white light emitting diodes attached inside to minimize fluctuations in air temperature between the light and
dark phases. Diapause was induced in adult TSSM females when the light phase was 24 h or shorter, and diapause induction was
inhibited when the light phase extended over 32 h. The development of deutonymphs was delayed under a diapause-inducing photoperiod.
Diapause inducing photoperiods may suppress an increase in the TSSM population, by slowing down development and reproduction. 相似文献
102.
in vitro including cotyledonary stage somatic embryos have the ability to grow photoautotrophically (without sugar in the culture
medium), and that the low or negative net photosynthetic rate of plants in vitro is due not to poor photosynthetic ability, but to the low CO2 concentration in the air-tight culture vessel during the photoperiod. Furthermore, we have shown that the photoautotrophic
growth of several woody plants in vitro can be significantly promoted by increasing the CO2 concentration and light intensity in the vessel, by decreasing the relative humidity in the vessel, and by using a fibrous
or porous supporting material with high air porosity instead of gelling agents such as agar. In this paper, the advantages
of photoautotrophic micropropagation in a conventional, small culture vessel with a microporous gas filter for enhancing natural
ventilation and in a large culture vessel with a forced ventilation unit are described for woody plants such as acacia (Acacia mangium), coffee (Coffea arabusta), eucalyptus (Eucalyptus camaldlensis), mangosteen (Garcinia mangostana), neem (Azadirachta indica), paulownia (Paulownia fortunei), and pine (Pinus radiata).
Received 30 August 2001/ Accepted in revised form 27 September 2001 相似文献
103.
Maeda T Sakoda S Suzuki T Makino N 《Canadian journal of physiology and pharmacology》2006,84(3-4):319-324
Possible somatic DNA recombination in the brain has been investigated by attempting to capture direct or indirect evidence of it. Until recently, the biological significance of the DNA event, the genes is involved in the recombination, or even whether the event actually occurs in the brain has remained unclear. The DNA-rearranged locus-oriented approach and the recombination activity-oriented approach have mutually contributed to the elucidation of the biological features of extra-immune system somatic DNA recombination. There have been only 2 loci proposed for the candidate, one is a repetitive sequence and the other DNA recombination is nonrepetitive locus. This review states conventional concepts and discussions chronologically and finally to the newest aspects of DNA rearrangement in the brain. 相似文献
104.
Characterization and cloning of the chlorophyll-degrading enzyme pheophorbidase from cotyledons of radish 下载免费PDF全文
Enzymatic removal of the methoxycarbonyl group of pheophorbide (Pheid) a in chlorophyll degradation was investigated in cotyledons of radish (Raphanus sativus). The enzyme pheophorbidase (PPD) catalyzes the conversion of Pheid a to a precursor of pyropheophorbide (PyroPheid), C-13(2)-carboxylPyroPheid a, by demethylation, and then the precursor is decarboxylated nonenzymatically to yield PyroPheid a. PPD activity sharply increased with the progression of senescence in radish, suggesting de novo synthesis of PPD. The enzyme activity was separated into two peaks in anion-exchange and hydrophobic chromatography; the terms type 1 and type 2 were applied according to the order of elution of these enzymes in anion-exchange chromatography. PPD types 1 and 2 were purified 9,999- and 6,476-fold, with a yield of 0.703% and 2.73%, respectively. Among 12 substrates tested, both enzymes were extremely specific for Pheids of the dihydroporphyrin and tetrahydroporphyrin types, indicating that they are responsible for the formation of these PyroPheids. Both PPDs had molecular masses of 113,000 kD on gel filtration and showed three bands of 16.8, 15.9, and 11.8 kD by SDS-PAGE. The partial N-terminal amino acid sequences for these bands of PPD (type 2) were determined. Based on their N-terminal amino acid sequences, a full-length cDNA of PPD was cloned. The molecular structure of PPD, particularly the molecular mass and subunit structure, is discussed in relation to the results of SDS-PAGE. 相似文献
105.
Yu Zhang Toyoki Furusawa Sheau Fung Sia Mitsuo Umezu 《Computer methods in biomechanics and biomedical engineering》2013,16(5):488-494
The purpose of this study was to propose an innovative approach of setting outlet boundary conditions for the computational fluid dynamics (CFD) simulation of human common carotid arteries (CCAs) bifurcation based on the concept of energy loss minimisation at flow bifurcation. Comparisons between this new approach and previously reported boundary conditions were also made. The results showed that CFD simulation based on the proposed boundary conditions gave an accurate prediction of the critical stenosis ratio of carotid arteries (at around 65%). Other boundary conditions, such as the constant external pressure (P = 0) and constant outflow ratio, either overestimated or underestimated the critical stenosis ratio of carotid arteries. The patient-specific simulation results furthermore indicated that the calculated internal carotid artery flow ratio at CCA bifurcation (61%) coincided with the result obtained by clinical measurements through the use of Colour Doppler ultrasound. 相似文献
106.
Yukihiro Ito Hiroharu Banno Toyoki Moribe Kokichi Hinata Yasunori Machida 《Molecular & general genetics : MGG》1994,245(1):1-10
A cDNA clone (cNPK15) was isolated from tobacco cells in suspension culture, which encodes a predicted protein kinase of 422 amino acids. The predicted NPK15 protein consists of a hydrophobic region near the amino-terminus, a linker domain and the catalytic domain of a protein-serine/threonine kinase in the carboxyl-half. NPK15 was not found to be closely related to any reported protein, but its putative catalytic domain shares some structural similarity with those of receptor-like protein kinases of plants, such as ZmPK1 from Zea mays and TMK1 from Arabidopsis, even though no receptor-like domain is found in NPK15. Recombinant NPK15 expressed in Escherichia coli as a fusion protein was found capable of autophosphorylation and of phosphorylation of the histone H1 protein on both serine and threonine residues. Upon overexpression of cNPK15 under control of the promoter of cauliflower mosaic virus 35S RNA in tobacco cells, into which it had been introduced by Agrobacterium-mediated transformation, the NPK15 gene acted as a suicide gene and blocked proliferation of the host cells. By contrast, such a suicide effect was not observed with the gene for a kinase-negative mutant protein in which the nucleotide sequence for the ATP-binding site had been mutated or with a mutant derivative encoding a protein in which the hydrophobic region had been deleted. Thus, the protein kinase activity of NPK15 and the hydrophobic region of the protein are responsible for the suicide effect. The NPK15 protein kinase seems to be associated with specific cellular functions. Southern blot analysis with cNPK15 as the probe detected several fragments in restriction digests of genomic DNAs from both tobacco and other members of the Solanaceae. This result suggests that NPK15-related genes constitute a small gene family in the genomes of Solanaceae. 相似文献
107.
Cui Yong-Yi Hahn Eun-Joo Kozai Toyoki Paek Kee-Yoeup 《Plant Cell, Tissue and Organ Culture》2000,62(3):219-226
Rehmannia glutinosa plantlets were cultured for 4 weeks under different culture conditions to determine the optimum environment for in vitro growth and ex vitro survival. Plantlet growth increased with an increasing number of air exchanges of the culture vessel, exhibiting greatest
shoot weight, total fresh weight, leaf area, and chlorophyll content at 4.4 h−1 of air exchanges. High sucrose concentration (30 g l−1) increased root weight but reduced shoot growth. Net photosynthetic rates of the plantlets were greatest when sucrose was
not added to the medium. On the other hand, ex vitro survival of the plantlets was not influenced by sucrose concentration. In the experiment on difference in photoperiod and
dark period temperatures (DIF) and photosynthetic photon flux (PPF), plantlet growth increased as DIF and PPF levels increased.
Particularly, increasing PPF level had a more distinctive effect on plantlet growth than increasing DIF level. The interaction
of DIF × PPF was also significant, showing the greatest plantlet growth in positive DIF (+8 DIF) and a high PPF (210 μmol
m−2 s−1). In conclusion, the results of this experiment suggest that increased number of air exchanges of the culture vessel, decreased
sucrose concentration, and positive DIF in combination with high PPF level enhanced growth and acclimatization of Rehmannia glutinosa plantlets.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
108.
Effects of sucrose concentration,supporting material and number of air exchanges of the vessel on the growth of in vitro coffee plantlets 总被引:3,自引:0,他引:3
Nguyen Quynh Thi Kozai Toyoki Van Nguyen Uyen 《Plant Cell, Tissue and Organ Culture》1999,58(1):51-57
Growth of coffee (Coffea arabusta) plantlets cultured in vitroas affected by sugar, types of supporting material and number of air exchanges of the vessel was investigated. Single node
cuttings of in vitro coffee plantlets were cultured on half strength MS medium with or without 20 g l−1 sucrose. Two types of supporting material, agar and Florialite, and two levels of air exchange expressed by number of air
exchanges per vessel, 0.2 and 2.3 h−1, were studied. At the end of a 40-day culture period, fresh weight, shoot length, root length and leaf area of plantlets
when cultured on Florialite soaked in sugar-free medium and under the higher number of air exchanges were greater than those
in sugar containing medium. Callus was observed at the shoot base of plantlets grown on agar medium containing sucrose. Photosynthetic
ability of coffee plantlets in vitro was also significantly increased when grown on sugar-free medium with the high number of air exchanges and Florialite as
a supporting material.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
109.
The association of coenzyme A(CoASH) and glutathione (GSH) with the water-soluble polymers and their esterolytic reactivities were evaluated through the reaction with p-nitrophenyl acetate in the presence of cationic polymer micelles: partially laurylated poly(2-ethyl-1-vinylimidazole) and poly(4-vinylpyridine). The polymer micelles with high lauryl-group content (more than 12 mol%) markedly accelerated the reaction at very low concentrations of the polymer. Other polymers with no or small lauryl-group content only slightly enhanced the association and the reaction rate. From the rate-polymer concentration profiles, the association constants (K) and the rate constants for thiol coenzymes bound to the polymer (k′a,bound) were determined: for polymers with more than 12 mol % lauryl-group content, KCoASH = 1110–2270 M?1, KGSH = 170–503M?1, k′a,bound at pH 8.65 = 142–341M?1 sec?1. k′a,bound were 20–340 times larger than that observed in the absence of the polymer. The logarithm of k′a,bound was found to be correlated well with the polymer hydrophobicity, indicating that the hydrophobic environment of the polymer activated the bound thiol anions. On the other hand, the polymer hydrophobicity did not correlate with the association constant. 相似文献
110.
Akinori Oki Masato Nishida Toyomi Satoh Hajime Tsunoda Kunitake Kasahara Kaoru Saijo Takeshi Kubo Tadao Ohno 《In vitro cellular & developmental biology. Animal》1998,34(4):290-297
Summary A novel human cell line, TOM-2, was established from a rare uterine cervical cancer, glassy cell carcinoma (GCC). TOM-2 is
the second established GCC cell line so far reported. The cells were intermediately or poorly differentiated with dysplastic
nuclei and polygonal shape and secreted two tumor markers and cytokines, i.e., CA-125 and SCC, interleukin (IL)-1α, -6, and
-8, and TNF-α. Growth of TOM-2 was so strongly dependent on population density that it was not possible to determine the plating
efficiency. In mass culture, the following characteristics were observed: doubling time, 83 h; mode of chromosome number,
79; human papillomavirus type 18 DNA, detectable; tumorigenicity, easily transplantable into subcutis of nude mice; chemosensitivity
in vitro, considerably sensitive to Cisplatin and 5-FU but not to 9 other antineoplastic agents. This novel cell line will be useful
for developing new therapeutic strategies for the rare cancer, GCC. 相似文献