Agrobacterium-mediated transformation and regeneration of kiwi fruit

Summary Genetically transformed kiwi fruit (Actinidia deliciosa) plants were obtained from hypocotyl and stem segments co-cultured with Agrobacterium tumefaciens strain EHA101 harboring a binary vector, pLAN411 or pLAN421, which contained the neomycin phosphotransferase II (nptII) gene and the -glucuronidase (GUS) gene. After co-culturing with the A. tumefaciens, the hypocotyl or stem segments were cultured on a selection medium containing 25g/ml kanamycin and 500g/ml Claforan. After one month in culture, shoots had regenerated from the cuttings. Green shoots were analyzed for NPTII activity and GUS activity. Eighty-five percent of the green shoots examined expressed the nptII and GUS genes. GUS histochemical assays revealed strong GUS expression in guard cells, mesophyll cells, and trichomes.     

Behavioral responses of female oriental fruit flies to the odor of papayas at three ripeness stages in a laboratory flight tunnel (Diptera: Tephritidae)

Behavioral responses of adult female oriental fruit flies, Dacus dorsalisHendel, to the odor of papayas from three ripeness classes were studied using a threechoice flight tunnel bioassay. Laboratoryreared flies were allowed to respond freely to any of three papaya odors (mature green, colorbreak to one-fourth ripe, and one-half to full ripe) emanating from identical (spherical) fruit models. Five behaviors were measured in assessing the fly's relative attraction to the odors (number of landings), arrestment (total fly seconds on sphere), fly-fly interactions on the fruit model (maximum and modal fly density), and acceptance for oviposition (total eggs laid). Females showed no significant difference in total fly landings based on all age classes combined. Significant differences were noted among age classes. Females spent more total time on the sphere and showed a higher maximum density and modal fly density to ripe fruit than to green fruit odors. Ovipositional acceptance of fruit models based on the total number of eggs laid in a sphere was greater in response to the ripefruit odor than to the other two odor classes. Olfactorystimulated behavioral responses of females to the odor of ripe papayas were significantly different from the other ripeness classes for all behaviors at 8 days postemergence and then declined in 11-day-old flies. Behavioral responses were greater during the afternoon than in the morning. Observations of wild oriental fruit flies to papayas in the field indicated a preference for residing on riper fruit. The results of this study are discussed with regard to the role of olfactory inputs generated by the odor of ripening fruit on female attraction and oviposition behavior resulting in infestation of papayas by oriental fruit fly.     

Suppression of the degradation of recombinant human apolipoprotein E by a protease inhibitor obtained from fetal bovine serum in serum-free culture

The recombinant human apolipoprotein E (Apo-E) produced by Chinese hamster ovary cells (CHO-322 cells) in serum free culture was degraded to 24K and 23K fragments that contained N-terminal amino acid. The degradation site of Apo-E to 24K fragment was between Arg180 and Leu181 and the C-terminal amino acid of 23K fragment was Gly169. In fetal bovine serum (FBS)-containing culture, the degradation was inhibited. However, in calf serum (CS) the inhibitory activity was not detected. Thus, we attempted the purification of the factor with this inhibitory activity from FBS. A protease inhibitor was purified to give a single peak from FBS by ammonium sulfate precipitation and combination of several column chromatographies. When this FBS-derived protease inhibitor (FBS-d-PI) was added to serum-free culture of CHO-322 cells, degradation of recombinant Apo-E to the 24K and 23K fragments was dose-dependently suppressed and accumulation of intact Apo-E in culture supernatant was observed. FBS-d-PI was found to be a glycoprotein with relative molecular size of 75K daltons under reducing condition, and 85K daltons under nonreducing condition by SDS-PAGE. A complex of FBS-d-PI and a cellular protease was also detected in culture supernatant by western blot analysis using mouse monoclonal antibodies against FBS-d-PI.     

稻瘟菌诱导的水稻几丁酶、β-1.3-葡聚糖酶活性及分布

稻瘟菌(Pyricularia oryzae C.)孢子感染或菌丝培养液处理后,水稻的几丁酶和β-1,3-葡聚糖酶活力被分别诱导提高6～9倍和3～5倍。用亲和层析初步纯化的几丁酶在体外能降解稻瘟菌细胞壁和抑制它的孢子萌发。这两个酶在细胞间隙和细胞内都有分布。     

Characteristics of the interaction of calcium with casein submicelles as determined by analytical affinity chromatography

Interaction of calcium with casein submicelles was investigated in CaCl2 and calcium phosphate buffers and with synthetic milk salt solutions using the technique of analytical affinity chromatography. Micelles that had been prepared by size exclusion chromatography with glycerolpropyl controlled-pore glass from fresh raw skim milk that had never been cooled, were dialyzed at room temperature against calcium-free imidazole buffer, pH 6.7. Resulting submicelles were covalently immobilized on succinamidopropyl controlled-pore glass (300-nm pore size). Using 45Ca to monitor the elution retardation, the affinity of free Ca2+ and calcium salt species was determined at temperatures of 20 to 40 degrees C and pH 6.0 to 7.5. Increasing the pH in this range or increasing the temperature strengthened the binding of calcium to submicelles, similar to previous observations with individual caseins. However, the enthalpy change obtained from the temperature dependence was considerably greater than that reported for alpha s1- and beta-caseins. Furthermore, the elution profiles for 45Ca in milk salt solutions were decidedly different from those in CaCl2 or calcium phosphate buffers and the affinities were also greater. For example, at pH 6.7 and 30 degrees C the average dissociation constant for the submicelle-calcium complex is 0.074 mM for CaCl2 and calcium phosphate buffers, vs 0.016 mM for the milk salt solution. The asymmetric frontal boundaries and higher average affinities observed with milk salts may be due to binding of calcium salts with greater affinity in addition to the binding of free Ca2+ in these solutions.     

Decay of the tryptophan fluorescence anisotropy in bacteriorhodopsin and its modified forms.

In this work we study the decay of the polarization of the Trp fluorescence in native bacteriorhodopsin (bR), deionized bR (dlbR), and the retinal-free form of bR, bacterioopsin (bO), using picosecond laser/streak camera system. Two types of depolarization processes are observed, one around 250 ps, which is temperature independent around room temperature, and the other in the 1-3-ns range, which is sensitive to temperature and certain bR modifications. This suggests the presence of at least two different environments for the eight Trp molecules in bR. Native bR and deionized bR gave the same depolarization decay times, suggesting that the removal of metal cations does not change the microenvironment of the emitting Trp molecules. The slow component is faster in bO than in bR, suggesting a change in the environment of the Trp molecules upon the removal of the retinal chromophore. All these results are discussed in terms of the different mechanisms of Trp fluorescence depolarization. A comparison between the depolarization decay in rhodopsin and bR is made.     

Developmental interactions between the army wormLeucania separata [Lep.: Noctuidae] and its parasiteApanteles ruficrus [Hym.: Braconidae]

The developmental interactions between the gregarious endoparasitoidApanteles ruficrus Hal. and the army worm,Leucania separata Walker were investigated. The parasitoid preferred young host larvae and developed in 9.5 days irrespective of host age at the time of parasitization. The growth of parasitized host larvae were depressed. The net maximum weight of the host larva was positively correlated with the number of parasitoid eggs laid when the 2nd instar was parasitized. And when parasitizing in 2nd instar, the weight of parasitoid was negatively correlated with the number of eggs laid. The parasitoid has an ability to regulate the size of the host and the parasitoid itself according to the number of eggs laid when the host larva is very small.     

Utilization and requirements of amino acids by a cell line derived from the butterfly Papilio xuthus

The media, in which a butterfly cell line (Px 58), derived from pharate adult ovaries of Papilio xuthus cultured for 8 days, were analysed to examine the changes in free amino acids in the medium during cultivation. Beta-alanine, arginine, glycine, histidine, lysine, phenylalanine, proline, serine, and tryptophan did not change markedly. Asparagine, aspartic acid, cystine, glutamine, isoleucine, leucine, methionine, threonine, tyrosine, and valine decreased to some extent with culturing. Alpha-alanine increased markedly, and glutamic acid did so to a lesser extent. Requirements of amino acids by the cell line were examined by deleting amino acids one at a time. Deletion of alpha-alanine, beta-alanine, asparagine, glutamic acid, glycine, and phenylalanine did not cause deterioration of the cell. These amino acids were thought to be non-essential or required only a little. Deletion of other amino acids impaired the cell growth severely. These amino acids would appear to be essential for growth of the Px 58 cell line.     

Cryopreservation of infective larvae of Dipetalonema viteae.

infective larvae of Dipetalonema viteae produced infections in Mongolian jirds (Meriones unguiculatus) after storage of infected ticks (Ornithodoros tartakovskyi) in the presence of dimethyl sulfoxide (DMSO, 5%) for 7 or 595 days in liquid nitrogen (-196 C). Infectivity of these larvae was only partially impaired. Microfilaremias of test jirds were generally lower than those of control jirds given nonfrozen larvae; however, the majority of test jirds developed microfilarial counts suitable for use in infecting ticks. In contradistinction, larvae frozen free of the tick failed to retain infectivity. Apparently the tick, in conjunction with DMSO, protects the larvae during freezing and thawing.