逆境胁迫下作物基因表达更替的研究进展

本文综述了高等植物在厌氧、热激,盐分胁迫,养分胁迫,紫外辐射等各种逆境条件下,基因表达更替的一系列过程,提出基因表达变化对作物适应逆境条件的意义,并对今后的研究作了展望。     

干旱条件下大豆叶片H_2O_2代谢变化及其同抗旱性的关系

干旱条件下大豆叶片H_2O_2含量增加,AsA POD与 GR活性均表现“先上升后下降”的趋势。叶片AsA与GSH含量均随干旱时间的延长而逐渐下降,而PPOD活性则持续增加。抗旱性较强的小粒大豆品种7605在干旱条件下能维持较强的 H_2O_2清除能力,H_2O_2累积较少。     

Insights gained into the interpretation of surface electromyograms from the gastrocnemius muscles: A simulation study

Interpretation of surface electromyograms (EMG) is usually based on the assumption that the surface representation of action potentials does not change during their propagation. This assumption does not hold for muscles whose fibers are oblique to the skin. Consequently, the interpretation of surface EMGs recorded from pinnate muscles unlikely prompts from current knowledge. Here we present a complete analytical model that supports the interpretation of experimental EMGs detected from muscles with oblique architecture. EMGs were recorded from the medial gastrocnemius muscle during voluntary and electrically elicited contractions. Preliminary indications obtained from simulated and experimental signals concern the spatial localization of surface potentials and the myoelectric fatigue. Specifically, the spatial distribution of surface EMGs was localized about the fibers superficial extremity. Strikingly, this localization increased with the pinnation angle, both for the simulated EMGs and the recorded M-waves. Moreover, the average rectified value (ARV) and the mean frequency (MNF) of interference EMGs increased and decreased with simulated fatigue, respectively. The degree of variation in ARV and MNF did not depend on the pinnation angle simulated. Similar variations were observed for the experimental EMGs, although being less evident for a higher fiber inclination. These results are discussed on a physiological context, highlighting the relevance of the model proposed here for the interpretation of gastrocnemius EMGs and for conceiving future experiments on muscles with pinnate geometry.     

盘二孢属一新种——花椒盘二孢

花椒盘二孢Marssonina zanthoxyla Y.J.Lu et G.L.Li sp.nov.是寄生在芸香科花椒属植物上的一种寄生菌,本文有汉文和拉丁文的形态描述和新种的讨论。     

银杏核用品种产量性状指标的变异及聚类分析

选用20个国内外大粒、早实、优质银杏核用品种,采用随机区组试验设计,连续4a对6个产量性状指标的变异及聚类分析进行了研究．结果表明,20个品种4a平均产量性状指标的变异系数大于50％．Q型系统聚类表明,20个品种可以分成5类,日本的“岭南”和“黄金丸”为最丰产品种．不同年份不同品种归属不同类别．本研究为银杏丰产品种选育奠定了生物数学基础．     

Synthesis and disulfide bond connectivity–activity studies of a kalata B1-inspired cyclopeptide against dengue NS2B–NS3 protease

Kalata B1 is a plant protein with remarkable thermal, chemical and enzymatic stability. Its potential applications could be centered on the possibility of using its cyclic structure and cystine knot motif as a scaffold for the design of stable pharmaceuticals. To discover potent dengue NS2B–NS3 protease inhibitors, we have prepared various kalata B1 analogues by varying the amino acid sequence. Mass spectrometric and biochemical investigations of these analogues revealed a cyclopeptide whose two fully oxidized forms are substrate-competitive inhibitors of the dengue viral NS2B–NS3 protease. Both oxidized forms showed potent inhibition with K_i of 1.39 ± 0.35 and 3.03 ± 0.75 μM, respectively.     

风信子花器官中HAP2基因的分离与表达研究(英文)

在离体条件下,以风信子花被片为外植体,通过控制激素的浓度可诱导花被片、雄蕊或胚珠的再生。近年来,在拟南芥和金鱼草等模式植物中已经分离出了许多控制花器官发育的同源异形基因,如AG,AP1,AP2,AP3等,其中AP2在控制花萼和花瓣形成过程中起重要作用,因此本文从风信子中分离AP2的同源基因,并对它在风信子再生系统中的表达进行了分析。根据AP2同源基因功能域的保守序列设计一对简并引物：5'-TGGGA（A/G）TC（G/T/C）CA（C/T）AT（C/T）TGGA-3'和5'-TCCCA(AGC)(CT)(GT)(AG)CC(AG) CA(CT)TT(AG)TG-3', 以再生的花被片为材料进行RT-PCR,扩增出大小约300bp的片段,序列分析表明该片段的氨基酸序列与AP2同源性高达89%。进而,利用5’和3’Race PCR,得到全长的cDNA。该基因命名为HAP2,GenBank登记号为AF134116,该基因全长1597bp,编码368个氨基酸(Fig.1）。与AP2相比,HAP2也含有10个氨基酸长的碱性功能域,其中KKSR为核定位信号。此外,HAP2也含有两个序列重复的68个氨基酸长的功能域（HAP2-R1,HAP2-R2）,HAP2-R1也含有能形成(-螺旋结构的核心区域,且与AP2-R1中的核心序列100%同源,而HAP2-R2中的核心区域与AP2-R2相比, 缺少9个氨基酸(Fig.2）。RT-PCR结合Southern 杂交结果表明(Fig.3）,HAP     

中国瘿蚊一新种记述(双翅目,瘿蚊科)

记述采自浙江省的端突瘿蚊属Epidiplosis 1新种:指状端突瘿蚊Epidiplosis dactylina sp.nov,.模式标本存放于山东农业大学昆虫标本室.     

短角瘿蚊属一新种记述(双翅目,瘿蚊科)

记述了采自山东省的短角瘿蚊1新种:泰山短角瘿蚊Anarete taishanensis sp.nov.,模式标本存放于山东农业大学昆虫标本室.