‘红巴梨’果皮UFGT基因的克隆及表达分析

以‘巴梨’红色芽变品种‘红巴梨’果皮为材料,采用同源克隆技术和RACE结合的方法,克隆了UFGT(UDP-葡萄糖:类黄酮3-O-葡萄糖基转移酶)蛋白的部分cDNA,命名为Pc UFGT。结果表明:该cDNA片段长为1 089 bp,与苹果UFGT基因序列一致性达89%,氨基酸序列同源性为85%,含有糖基转移酶的UDPGT、COG1819和MGT等保守域。荧光实时定量PCR分析表明,该基因在‘红巴梨’幼果期表达强度约为‘巴梨’的2倍,而果实成熟期表达强度略低于‘巴梨’;该基因在‘红巴梨’果肉中不表达。     

On Bartlett's formulation of the Luria-Delbrück mutation model

Current knowledge of microbial mutation rates was accumulated largely by means of fluctuation experiments. A mathematical model describing the cell dynamics in a fluctuation experiment is indispensable to the estimation of mutation rates through fluctuation experiments. In almost six decades the model formulated by Lea and Coulson dominated in research and application, although the model formulated by Bartlett is generally believed to describe the cell dynamics more faithfully. The neglect of the Bartlett formulation was mainly due to mathematical difficulties. The present investigation overcomes some of these difficulties, thereby paving the way for the application of the Bartlett formulation in estimating mutation rates. Specifically, the article offers an algorithm for computing the distribution function of the number of mutants under the Bartlett formulation. The article also provides algorithms for computing point and interval estimates of mutation rates that are based on the maximum-likelihood principle. In addition, the article examines and compares the asymptotic behavior of the distributions of the number of mutants under the two formulations.     

Auxin inhibition of ripening in bartlett pears

The effect of indoleacetic acid and 2,4-dichlorophenoxyacetic acid on the ripening of intact mature-green pears (Pyrus communis var. Bartlett) was investigated using a vacuum infiltration technique.     

Isolation, Purification, and Characterization of an Endogenous Root-promoting Factor Obtained from Basal Sections of Pear Hardwood Cuttings

Basal segments taken from Old Home and Bartlett pear hardwood cuttings collected at intervals during the rooting period in September were extracted with ethanol and fractionated by paper chromatography in different solvent systems. Different zones on the chromatograms were bioassayed by the mung bean rooting test, which showed high levels of promotion in Old Home basal extracts when the cuttings were obtained during the period of maximum rooting. Extracts from Bartlett cuttings, however, showed considerably less promotion activity in the bioassay but did show high levels of inhibitory activity.

After the easily-rooted Old Home cuttings had been in the rooting medium for 10 days, a highly active endogenous root-promoting material was found in extracts from basal segments of cuttings having buds and which had been treated with indolebutyric acid. Similar extracts obtained from disbudded cuttings, or from cuttings with buds but not treated with indolebutyric acid, lacked this rooting-factor. Extracts obtained from all types of the difficult-to-root Bartlett cuttings also lacked this rooting-factor. The latter is believed to be produced by physiologically active Old Home buds, and is very effective in the mung bean bioassay, even at extremely low concentrations.

From paper chromatographic studies, tests with spray reagents, solubility determinations, biological tests, UV spectrum analysis, and infrared spectroscopy, it is believed that this rooting factor could be a condensation product between exogenous auxin (indolebutyric acid) and a phenolic compound produced by physiologically active Old Home pear buds.

     

A simplified method for inorganic phosphate determination and its application for phosphate analysis in enzyme assays

A simplified method for inorganic phosphate determination has been developed. The method is sensitive, easy, economic, and applicable for estimation of phosphate released in both enzymatic and nonenzymatic reactions. A mixture of hydrazine sulfate and ascorbic acid was used as the reducing agent and the conditions for the development of the molybdenum blue color were optimized. Thus in the 4.0 ml assay system, 0.4 ml of the reducing agent solution containing 20 mg each of hydrazine sulfate and ascorbic acid per milliliter of 1.0 N H2SO4 gave a rapid optimum color development with absorption maximum at 820 nm. Color development showed a linear relationship up to 10 microg Pi concentration. Thus the method has a 2.5x higher range of Pi estimation than that of the Bartlett method. The molar extinction coefficient at 820 nm was higher than that obtained in the Bartlett procedure. Also the molybdenum blue color formed was stable up to 24 h. Under the standard assay conditions, interference from acid-labile phosphate as in the case of Na+,K+ ATPase was at the minimum. The applicability of the method for assay of microsomal Na+,K+ ATPase and glucose-6-phosphatase was checked in microassays (final volume 0.1 ml) in comparison to the conventional procedures which use 3-4 times higher volumes. Likewise the applicability of the method for phospholipid analysis was compared with that of the conventional Bartlett method. Under both test systems the results obtained by the micromethod were identical to those obtained by the conventional methods. In general the method, which rapidly produces quantitatively molybdenum blue color, not only is rapid economical, and convenient but also has wide applicability.     

Effect of gamma radiation on the ripening of bartlett pears

Gamma radiation at doses of 300 Krad or more inhibits the ripening of Bartlett pears (Pyrus communis L.). Immediately after irradiation there is a transitory burst of C₂H₄, which subsequently declines in fruits subjected to inhibitory doses. Ethylene production associated with ripening begins at the same time in unirradiated fruits and those subjected to noninhibitory doses, but the latter produces much more C₂H₄ at the climacteric peak. Fruits subjected to inhibitory doses produce low levels of C₂H₄ unless subjected to exogenously applied C₂H₄, whereupon they produce enough of the gas to induce ripening in unirradiated fruits.

Pears subjected to 300 and 400 Krad of gamma rays did not ripen even when held in a flowing atmosphere containing 1000 ppm of C₂H₄ for 8 days at 20°. It is concluded that the action of gamma rays on Bartlett pears involves both an inhibition of C₂H₄ production and a decreased sensitivity of the fruit to the ripening action of the gas. Ripening of Bartlett pears is inhibited by gamma radiation only when applied to preclimacteric fruit.

     

Film Reviews

Book reviewed in this article:
Looking for Me . 1970. A film by Norris Brock and Virginia Bartlett , produced by the American Dance Therapy Association
Dance Therapy: The Power of Movement . 1982. A film by Norris Brock produced by the American Dance Therapy Association     

BOOK REVIEWS

Fertility and the Family: The Glover Report on Reproductive Technologies to the European Commission
Cross Cultural Perspectives in Medical Ethics: Readings (The Jones and Bartlett Series in Biology) Ed. by Robert M. Veatch
Ending Lives, by Robert Campbell and Diane Collinson
Science and the Unborn: Choosing Human Futures by Clifford Grobstein     

Gravimetric determination of phospholipid concentration

Accurate determination of lipid concentrations is an obligatory routine in a research laboratory engaged in studies using this class of biomaterials. For phospholipids, this is frequently accomplished using the phosphate assay (Bartlett, G.R. Phosphorus Assay in Column Chromatography. J. Biol. Chem. 234, 466-468, 1959). Given the purity of the currently commercially available synthetic and isolated natural lipids, we have observed that determination of the dry weight of lipid stock solutions provides the fastest, most accurate, and generic method to assay their concentrations. The protocol described here takes advantage of the high resolution and accuracy obtained by modern weighing technology. We assayed by this technique the concentrations of a number of phosphatidylcholine samples, with different degrees of acyl chain saturation and length, and in different organic solvents. The results were compared with those from Bartlett assay, (31)P NMR, and Langmuir compression isotherms. The data obtained show that the gravimetric assay yields lipid concentrations with a resolution similar or better than obtained by the other techniques.     

不同栽培管理梨园梨小食心虫发生程度研究

梨小食心虫Grapholitha molesta(Busck)是梨园中的一种重要害虫。本论文采用性诱剂诱集法研究了不同栽培管理条件下梨园梨小食心虫发生的情况。结果表明,在5种不同种植模式的果园中,梨小食心虫在单植桃园中发生最重,试验期间梨小食心虫的日平均诱蛾量为10.9头/盆,与其他4种栽植模式果园的诱捕量均呈显著差异,且混有桃树的果园中梨小食心虫的发生数量多,而单植梨园、梨苹果混栽园、单植苹果园的梨小食心虫发生相对较轻。果实套袋的管理方法也可以显著降低梨小食心虫的发生数量,非套袋梨园的日平均诱捕量为13.8头/盆,是套袋梨园的1.52倍。试验还表明,不同品种和不同树龄的梨树对梨小食心虫的抗虫性均存在显著差异。酥梨比巴梨的抗虫性差,试验期间酥梨园的日平均诱捕量为12.6头/盆,是巴梨园的2.21倍,而40年老酥梨园日平均诱蛾量为12.5头/盆,是20年酥梨园诱蛾量的2.5倍。     

Heat stress responses in cultured plant cells : effect of culture handling and age

The pipetting of pear (Pyrus communis cv Bartlett) suspension cultures was followed by a substantial but transient decrease in heat sensitivity. During a culture cycle, pear cells were most sensitive to heat at day 3, which coincided with the period of most active cell division. To minimize serious artifacts, the influence of culture handling and age on parameters such as heat sensitivity must be standardized.     

Genetic linkage maps constructed by using an interspecific cross between Japanese and European pears

Genetic linkage maps of the European pear ( Pyrus communis L.) cultivar 'Bartlett' and the Japanese pear ( Pyrus pyrifolia Nakai) cultivar 'Housui' were constructed based on AFLPs, SSRs from pear, apple and Prunus, isozymes and phenotypic traits by using their F(1) progenies. The map of the female parent Bartlett consisted of 226 loci including 175 AFLPs, 49 SSRs, one isozyme and one S locus on 18 linkage groups over a total length of 949 cM, while that for 'Housui' contained 154 loci including 106 AFLPs, 42 SSRs, two phenotypic traits and the other four markers on 17 linkage groups encompassing a genetic distance of 926 cM. These maps were partially aligned using 20 codominant markers which showed segregating alleles in both parents. Compared with the reports of apple genetic maps, these pear maps were not saturated but were near saturation. Distorted segregation was observed in two and one regions of the genome of Bartlett and Housui, respectively. The position of 14 SSRs originating from apple could be successfully determined in pear maps, which enabled us to compare the two maps. Some SSRs developed from Prunus (peach, cherry) were also mapped. The relationships between pear and the other species belonging to the Rosaceae were discussed based on the position of SSRs.     

Silanediol-based inhibitor of thermolysin

The first silanediol inhibitor of thermolysin is reported, prepared by analogy with the Grobelny/Bartlett phosphinate inhibitor. A Cbz group on nitrogen proved to be unstable to the triflic acid mediated silanediol deprotection and was replaced with a dihydrocinnamoyl group. The silanediol was prepared in high purity by hydrolysis of a difluorosilane intermediate and proved to be an effective inhibitor, differing from the phosphinate by a factor of 4 (K_i=41 nM).     

Measurement of 32P following colorimetric phosphorus analysis

A procedure for the determination of both ³²P and phosphate contents on the same sample has been described. Following phosphate estimation by the method of Bartlett (5), the solution containing the blue reduced phosphomolybdate complex is decolorized at high pH. ³²P is measured in this transparent aqueous solution with a liquid scintillation spectrometer, without the addition of scintillators, by utilizing the ?erenkov radiation.     

Respiratory changes with stratification of pear seeds

Experiments on the stratification of seeds of pear ( Pyrus communis cv. Bartlett) indicate that there is a progressive increase in respiratory capacity, with about a three-fold increase developing during a 30-day stratification period. Evidence is presented suggesting this increase in respiratory capacity occurs in the cytochrome oxidase pathway and not in the alternative pathway of respiration. The increase is much less pronounced if the seeds are held at 25°C rather than at 6°C. The seed coat serves as a barrier to the expression of the increased respiratory capacity.     

On predicting extinction in simple population models. I. Stochastic linearization

The technique of stochastic linearization derived by Bartlett is used to give an approximate solution to each of three stochastic models of predation. By defining the existence of a quasi-stationary equilibrium distribution of population sizes, the approximate variances and covariances of the joint distribution of population sizes are calculated. The results are used to predict whether prey or predators are likely to become extinct first and the predictions are tested against simulation data. The linearization technique is a good predictor of the outcome of extinction but not of how long it takes.     

Vernonia georgiana—Species or hybrid?

Vernonia georgiana Bartlett was demonstrated to be of hybrid origin by means of hybridization experiments and comparisons of the artificial F₁ hybrids with herbarium specimens ofV. georgiana. The two parental species areV. angustifolia Michx. andV. acaulis (Walt.) Gleason.     

Structural deterioration of tendon collagen in genetic muscular dystrophy.

The structure of gastrocnemius tendons from chickens with genetically induced muscular dystrophy has been studied by low-angle X-ray diffraction. Compared with normal samples there is poor alignment of collagen within the tendons. This difference is quite pronounced at eight weeks when the affected birds are still in comparatively good physical condition. Similar changes have been reported for birds with nutritionally induced muscular dystrophy (Bartlett, M. W., Egelstaff, P. A., Holden, T. M., Stinson, R. H. and Sweeny, P. R. (1973) Biochim. Biophys. Acta 328, 213-220).     

FOLIAR PENETRATION OF NAPHTHALENEACETIC ACID: ENHANCEMENT BY LIGHT AND ROLE OF STOMATA

Light enhanced the penetration of naphthaleneacetic-1-¹⁴C acid (NAA) into the stomatous lower surface of pear (Pyrus communis L. cv. Bartlett) leaf discs. The light effect was rapidly lost on transfer to the dark and was diminished by pretreatment of leaf discs with a Hill reaction inhibitor (2-chloro-4-ethylamino-6-isopropyl-amino-s-triazine). The effect of light on NAA penetration was isolated from its effect on stomatal opening. A similar stimulation of NAA penetration was obtained with stomata opened and closed, providing evidence that penetration did not take place by mass movement into the substomatal chamber.