Endogenous gibberellins and inhibitors in caryopses of rye

Gibberellins A₈, A₁₆, A₂₄, and abscisic acid were identified by GC-MS of derivatized extracts from immature fruits of Secale cereale. Mature caryopses contained ABA and trans-ABA in a ratio 1:1 as well as 4′-dihydrophaseic acid. During milk ripeness a neutral GA conjugate was detected. Free GA, afforded by enzymatic hydrolysis of the conjugate, was chromatographically identified as GA₁₆     

重楼中一株产纤维素酶内生真菌的分离及鉴定

从重楼根茎中分离、鉴定具有产纤维素酶活性的内生真菌.采用表面消毒法从重楼块茎中分离内生真菌;用纤维素酶活性CMC平板检测分离菌株的产纤维素酶活性;对高产菌株进行形态学观察和分子生物学测序鉴定;探究影响纤维素酶活力的因素;利用平板法检测该株菌产其他胞外水解酶的活性.从3个来源的重楼中分离出41株内生真菌,通过平板检测发现...     

Subunit interactions in ABC transporters: towards a functional architecture

The ABC superfamily is a diverse group of integral membrane proteins involved in the ATP-dependent transport of solutes across biological membranes in both prokaryotes and eukaryotes. Although ABC transporters have been studied for over 30 years, very little is known about the mechanism by which the energy of ATP hydrolysis is used to transport substrate across the membrane. The recent report of the high resolution crystal structure of HisP, the nucleotide-binding subunit of the histidine permease complex of Salmonella typhimurium, represents a significant breakthrough toward the elucidation of the mechanism of solute translocation by ABC transporters. In this review, we use data from the crystallographic structures of HisP and other nucleotide-binding proteins, combined with sequence analysis of a subset of atypical ABC transporters, to argue a new model for the dimerisation of the nucleotide-binding domains that embraces the notion that the C motif from one subunit forms part of the ATP-binding site in the opposite subunit. We incorporate this dimerisation of the ATP-binding domains into our recently reported beta-barrel model for P-glycoprotein and present a general model for the cooperative interaction of the two nucleotide-binding domains and the translocation of mechanical energy to the transmembrane domains in ABC transporters.     

Restriction site insertion-PCR (RSI-PCR) for rapid discrimination and typing of closely related microbial strains

Taking advantage of point mutations between DNA sequences of closely related microbial strains, PCR primers modified with respect to the target sequence at positions 2-5 near the 3' end were designed to obtain a fragment harbouring an artificial restriction site specific for a given strain. The modified forward primer coupled with a specific reverse primer allows for the amplification of DNA fragments which can be digested with the specific endonuclease only in those strains where the restriction site is inserted by the DNA polymerase. The effectiveness of the method, named restriction site insertion-PCR (RSI-PCR), was tested on isolates of the 'Bacillus cereus group' for the rapid typing and discrimination of these closely related strains.     

地衣芽孢杆菌碱性蛋白酶的研究 Ⅰ.碱性蛋白酶高产菌的筛选及产酶条件初探

从成都佳丰食品厂等处采集的样品中平板分离初筛到124株碱性蛋白酶产生菌,进一步复筛出一株高产,且稳定的碱性蛋白酶产生菌株B．L．JF-ld,初步鉴定为地衣穿孢杆菌（Bacilluslicheniformis）。该菌的最适产酶条件为：培养基（％）为麦芽糖7．5,酵母膏3,NaCl0．5,K2HPO4·3H2O0．53,NaHPO4·2H2O0．03,Na2CO30．056,MnSO4l×10－4mol／L,pH8．7,通气量为（1：0．5）～（1：1）（v／v）,37℃发酵40h,酶活力单位高达7180U／ml。     

川明参根部的化学成分

从我国特有的单种属药用植物川明参（Ｃｈｕａｎｍｉｎｓｈｅｎ ｖｉｏｌａｃｅｕｍ　 Ｓｈｅｈ ｅｔ Ｓｈａｎ）中分离出８个晶体,经理化性质和波谱分析分别鉴定为：５,８－二甲氧基补骨脂素（晶Ⅰ）,５－异戊烯基－８甲氧基补骨脂素（晶Ⅱ）, ｐｒｏｃｙａｎｉｄｉｎ Ａ－２（晶Ⅲ）,槲皮素－３－Ｏ－葡萄糖醛酸甙（晶Ⅳ）,芦丁（晶Ⅴ）,豆甾醇（晶Ⅵ）,豆甾醇－葡萄糖甙（晶Ⅶ）及棕榈酸,硬脂酸的混合物（晶Ⅷ）。上述化合物均为首次从该植物中分离得到。     

农业害虫发生动态的Fuzzy优选识别模式及其应用

本文对山东省曲阜市１９８２－１９９４年二代棉铃虫发生动态的虫情与相应年份的气象资料进行了数量分析,应用Ｆｕｚｚｙ优选识别原理,建立了二代棉铃虫发生动态的Ｆｕｚｚｙ优选识别模式·对历史资料进行回代验证,其历史拟合率为 １００％．书 １９９５,１９９６ 两年的观测数据资料作为独立样本进行试报,预测结果与实际一致．本研究为农业害虫发生动态的预测预报提供了一种新的研究方法．     

利用RAPD技术快速鉴定番茄体细胞无性系变异

从以镰刀菌酸为选择剂筛选的番茄再生植株和未经筛选的植株叶片中提取ＤＮＡ,建立了适合番茄ＲＡＰＤ分析的ＰＣＲ条件,进一步在６０个随机引物中找到了４个可用于鉴定四个番茄品种体细胞无性系变异的引物。利用该法鉴定体细胞无性系变异不仅简单、迅速、可靠,而且因ＤＮＡ的用量少,不影响被检植株的后期生长,可尽早淘汰那些生理适应性而非分子水平发生变异的再生植株。     

AN OCEAN-BASIN-WIDE MARK-RECAPTURE STUDY OF THE NORTH ATLANTIC HUMPBACK WHALE (MEGAPTERA NOVAEANGLIAE)

Although much is known about the humpback whale, Megaptera novaeangliae, regional studies have been unable to answer several questions that are central to the conservation and management of this endangered species. To resolve uncertainties about population size, as well as the spatial and genetic structure of the humpback whale population in the North Atlantic, we conducted a two-year ocean-basin-wide photographic and biopsy study in 1992-1993. Photographic and skin-biopsy sampling was conducted of animals in feeding and breeding areas throughout most of the range of this species in the North Atlantic, from the West Indies breeding grounds through all known feeding areas as far north as arctic Norway. A standardized sampling protocol was designed to maximize sample sizes while attempting to ensure equal probability of sampling, so that estimates of abundance would be as accurate and as precise as possible. During 666 d at sea aboard 28 vessels, 4,207 tail fluke photographs and 2,326 skin biopsies were collected. Molecular analyses of all biopsies included determination of sex, genotype using six microsatellite loci, and mitochondrial control region sequence. The photographs and microsatellite loci were used to identify 2,998 and 2,015 individual whales, respectively. Previously published results from this study have addressed spatial distribution, migration, and genetic relationships. Here, we present new estimates of total abundance in this ocean using photographic data, as well as overall and sex-specific estimates using biopsy data. We identify several potential sampling biases using only breeding-area samples and report a consistent mark-recapture estimate of oceanwide abundance derived from photographic identification, using both breeding and feeding-area data, of 10,600 (95% confidence interval 9,300-12,100). We also report a comparable, but less precise, biopsy-based estimate of 10,400 (95% confidence interval of 8,000-13,600). These estimates are significantly larger and more precise than estimates made for the 1980s, potentially reflecting population growth. In contrast, significantly lower and less consistent estimates were obtained using between-feeding-area or between-breeding-area sampling. Reasons for the lower estimates using the results of sampling in the same areas in subsequent years are discussed. Overall, the results of this ocean-basin-wide study demonstrate that an oceanwide approach to population assessment of baleen whales is practicable and results in a more comprehensive understanding of population abundance and biology than can be gained from smaller-scale efforts.