一个快速响应干旱的F-box基因的克隆和表达分析

F-box是Skp1-Cullin1-F-box (SCF)型泛素连接酶E3的重要组成部分,在泛素化介导的蛋白质降解中选择性识别靶蛋白。本文从谷子苗期干旱胁迫条件下构建的转录组文库中克隆到与耐旱早期响应相关的F-box基因,命名SiFBX (GenBank登录号为KC252635.1)。该基因全长510 bp,编码170个氨基酸。蛋白质结构预测表明,该蛋白含有丰富的精氨酸、亮氨酸、丝氨酸,缺少跨膜结构域及信号肽序列。系统进化分析表明,该基因与已报道的EID1和FBW4亲缘关系较近。在该基因上游1.9 kb序列处,预测到启动子的核心序列及与多种逆境胁迫相关的调控序列。荧光定量PCR分析表明,该基因分别在正常干旱、PEG和ABA诱导下,表达量出现显著变化。     

Agglomeration of Services in American Metropolitan Areas

The growth of many service industries among American metropolitan areas stem from an eclectic set of forces. These include market penetration effects of increasing importance of services throughout the economy, agglomeration effects in immature and deregulated industries, and institutional and infrastructure constraints. These diverse forces are interpreted as urbanization and localization economies. A cycle of centralization of 27 fast growing service industries is documented for MS As in the period 1977-84. The two agglomeration effects are tested directly, using a power function model that relates employment and establishment growth to MSA size and initial level of employment in a local industry. Localization economies rather than the general advantages of metropolitan size best explain the growth patterns. This result implies that service industrial complexes are rapidly emerging in American metropolitan areas.     

曲霉转化中药材的研究进展

微生物转化已成为中药现代化研究的热点之一,本文对微生物转化中使用频率高的曲霉菌转化中药材的应用进行综述,并对广泛使用的黑曲霉对人参皂苷、黄山药、槐米中的芦丁、虎杖中的白藜芦醇苷、黄芩等的转化应用进行了介绍。     

~(14)C-多菌灵和~(14)C-呋喃丹的单剂及混剂处理棉种后放射性物质在棉苗上的吸收与分布

一、前言多菌灵(Carbendazim,MBC),化学名称:0一二甲基-N-2-苯并咪唑氨基甲酸酯。它是一种高效、低毒、广谱的内吸杀菌剂。呋喃丹(Carbofuran,Furadan),化学名称:2,3-二氢-2,2一二甲基-F-苯并呋喃-N-甲基氨基甲酸酯。它是一种广谱杀虫、杀螨、杀线虫剂。具有触杀、内吸和胃毒作用。多菌灵和呋喃丹的合剂棉种包衣对于棉花苗期病虫害的防治效果显著。在我国,它被视为一种经济、有效的防治手段(Shen et al.     

Evolution of ocean temperature and ice volume through the mid-Pleistocene climate transition

Earth's climate underwent a fundamental change between 1250 and 700 thousand years ago, the mid-Pleistocene transition (MPT), when the dominant periodicity of climate cycles changed from 41 thousand to 100 thousand years in the absence of substantial change in orbital forcing. Over this time, an increase occurred in the amplitude of change of deep-ocean foraminiferal oxygen isotopic ratios, traditionally interpreted as defining the main rhythm of ice ages although containing large effects of changes in deep-ocean temperature. We have separated the effects of decreasing temperature and increasing global ice volume on oxygen isotope ratios. Our results suggest that the MPT was initiated by an abrupt increase in Antarctic ice volume 900 thousand years ago. We see no evidence of a pattern of gradual cooling, but near-freezing temperatures occur at every glacial maximum.     

不同外源药剂预处理对低温胁迫下玉米种子萌发的影响

以玉米品种郑单958和辽单632为试验材料,研究不同外源药剂预处理对低温胁迫下玉米种子萌发的影响.结果表明:不同种类和浓度药剂预处理可影响郑单958和辽单632玉米种子的耐冷性,5 mg·L<'-1>GA<,3>促进10℃低温下各品种种子的萌发,有利于幼苗和根系的生长,但不利于壮苗;1 mg·L<'-1>浓度ABA浸种...     

植物生长调节剂和微量元素对茶树花粉发芽率的影响

以福鼎大白茶树花粉为材料 ,研究植物生长调节剂和微量元素对茶树花粉发芽率的影响 .结果表明 :含有 10 - 2 0 mg· L-1的 GA3、1- 2 0 mg· L-1的 2 ,4 - D、2 0 - 10 0 mg· L-1的 Zn SO4 、5 - 2 0 0 mg· L-1或稍高的H3BO3的培养液对花粉的发芽有明显的促进作用 .H3BO3质量浓度为 2 0 0 mg· L-1时 ,其发芽率最高 ,达84 .5 3% ,比 CK高 110 .3% ;而含有 5 0 - 10 0 mg· L-1的 GA3、5 0 - 10 0 mg· L-1的 2 ,4 - D、高于 2 0 0 mg· L-1的Zn SO4 的培养液则对花粉的发芽有明显的抑制作用 ,2 ,4 - D质量浓度为 10 0 mg· L-1时 ,发芽率最低 ,比 CK低 95 .2 % .     

Synthesis and herbicidal activity of new 3-(3-bromothiophen-2-yl)-5-(2,6-difluorobenzyl)oxymethyl-5-methyl-4,5-dihydroisoxazole as a paddy field herbicide

A new compound 3-(3-bromothiophen-2-yl)-5-(2,6-difluorobenzyl)oxymethyl-5-methyl-4,5-dihydroisoxazole was synthesized and the herbicidal activity was assessed under glasshouse and flooded paddy field conditions. This compound demonstrated good rice selectivity and potent herbicidal activity against annual weeds at 125 g ai ha⁻¹ under greenhouse conditions. Soil application of this compound showed the complete control of barnyardgrass to the 4th leaf stage at 250 g ai ha⁻¹. Field trials indicated that this compound, combined with pyrazosulfuron-ethyl, controlled annual and perennial weeds rapidly with good tolerance by transplanted rice seedlings from postemergence and soil application. This compound showed a low mammalian and environmental toxicity in various toxicological tests.     

Expression of nuclear factor-κB in asthmatic guinea pigs and the effect of erigeron breviscapus on it

AIM:To explore the expression of nuclear factor-κB(NF-κB)in asthmatic guinea pigs,and the effect of erigeron breviscapus,a protein kinase C(PKC)inhibitor,on the expression of nuclear factor-κB(NF-κB).METHODS:48 guinea pigs were randomly divided into 6 groups(n=8).Airway resistance and eosinophilic inflammation of airway wall were examined,the expression of NF-κB in the lung tissue was detected by immunohistochemical staining.RESULTS:The expression of NF-κB was mainly found in airway epithelium,all the asthmatic animals showed significantly higher optical densities than that of the normal control group(P＜0.01),and the rats subjected therapeutic treatment for two weeks showed significantly lower NF-κB expression than those of the asthmatic groups(P＜0.01).Positive correlation exist between the airway resistance and the percentage of cells expressing NF-κB in epithelium,and between the amount of eosinophil in airway wall and the percentage of cells expressing NF-κB in epithelium(P＜0101).CONCLUSION:The increased expression of NF-κB in airway epithelium of the asthmatic guinea pigs suggested that NF-κB may be involved in asthma.And result that the increased expression of NF-κB was inhibited significantly by the treatment of the erigeron breviscapus suggested that PKC may play a significant role in the pathogenesis of asthma through NF-κB.     

Effect of Acute Bull Exposure Around the Time of Artificial Insemination on Serum Oxytocin and Progesterone Concentrations and Pregnancy Rates in Dairy Cows

This study examined the effect of acute bull exposure around the time of artificial insemination (AI) on oxytocin and progesterone concentrations, and pregnancy rates in dairy cows. Ninety six dairy cows, stratified according to parity into primiparous and pluriparous, were divided into three groups; short bull exposure (SBE; 10 min, n = 32), long bull exposure (LBE; 4 h, n = 32) or no bull exposure (NBE; n = 32). On day 45 post‐partum, all cows were treated with PGF2α on three occasions 11–14 days apart to synchronize oestrus. They were submitted to fixed time AI 80 h after the third PGF2α injection. Cows in the SBE and LBE groups were artificially inseminated 5 min after the introduction of the bull. From a subset of cows (n = 6 per group; three primiparous and three pluriparous), blood samples were collected once every 5 min starting 15 min before AI until 15 min after AI and analysed for oxytocin concentrations. Additional blood samples were collected for measurements of progesterone (P4) concentrations once daily for 4 days starting on the day of AI and once every 3 days thereafter until day 22. The effects of bull exposure, time, parity, difficulty of AI, and pregnancy on oxytocin and P4 concentrations were analysed using the mixed linear model procedure. Mean oxytocin concentrations or change in oxytocin concentrations after bull exposure or AI were not different among groups. Pregnancy rates for the NBE, SBE and LBE groups were 55.5%, 33.3% and 44.4%, respectively, and were not different among groups. In conclusion, acute bull exposure around the time of AI did not affect oxytocin and progesterone concentrations and did not improve pregnancy rates in dairy cattle under these farms conditions.