原卟啉原氧化酶抑制剂类除草剂进展概况

本文对近期开发的原卟啉氧化酶抑制剂按用途进行了简要的介绍。文中涉及原卟啉氧化酶抑制剂的化学结构、生物活性、登记与专利和开发公司等。     

Biochemical study of resistance to imidacloprid in B biotype Bemisia tabaci from Guatemala

Systemic uptake bioassays using excised cotton leaves confirmed resistance to imidacloprid in a Guatemalan population of the tobacco whitefly Bemisia tabaci Gennadius. Polyacrylamide gel electrophoresis of naphthyl esterases identified the insects as B-types. Upon collection from the field, resistance was determined to be 58-fold relative to a susceptible strain originating in the Imperial Valley of California. Resistance levels increased to 126-fold in this population during its continuous exposure to systemically treated cotton. In biochemical investigations, there was no detectable NADPH-dependent mixed function oxidase metabolism of 14C-imidacloprid at any time during the selection process. In contrast, microsomal preparations from housefly abdomens readily produced significant amounts of the mono-hydroxy and olefin derivatives of the parent compound. Detoxification of imidacloprid by housefly MFOs may account for reports of lower toxicity of the insecticide towards this insect compared with whiteflies, despite similar binding properties between imidacloprid and the nicotinic acetylcholine receptors in both species.     

Modifying Myxococcus xanthus protoporphyrinogen oxidase to plant codon usage and high level of oxyfluorfen resistance in transgenic rice

Protoporphyrinogen oxidase (Protox) of Myxococcus xanthus (Mx Protox) is a 49-kDa membrane protein that catalyzes conversion of protoporphyrinogen IX (Protogen IX) into protoporphyrin IX (Proto IX). Upon heterologous expression in transgenic rice plants, Mx Protox is dually targeted into plastids and mitochondria, increasing resistance against the herbicidal Protox inhibitor oxyfluorfen. Here, we describe the chemical synthesis of the Mx Protox gene by assembling several small synthetic DNA fragments derived by ligation-PCR. Codon usage in the resulting 1416-bp gene was modified to correspond to that of the Arabidopsis Protox gene, a change that resulted in a decrease in G+C content from 71 to 49%. The modified Mx Protox gene was used to generate transgenic rice plants via Agrobacterium-mediated transformation. Integration, expression, and inheritance of the transgenes were demonstrated by Southern, Northern, and Western blot analyses. In plants transformed with the modified, low G+C-content Mx Protox gene, levels of Protox expression and enzyme activity were low compared to the levels observed for plants transformed with the native Mx Protox gene. Nonetheless, like the native gene, the modified gene conferred a high level of resistance to the herbicide oxyfluorfen in a seedling growth test.     

不同装液量对金顶侧耳液体摇瓶培养的影响

以食用菌金顶侧耳为试验研究对象;用综合PDA(马铃薯20 g,葡萄糖20 g,硫酸镁1.5g,磷酸二氢钾3.0g,水1 000 mL,pH自然)为液体培养基;以(25±1)℃,180 r/min为气浴恒温振荡器的温度和振荡速率.设定了60、80、100、120、140 mL 5个不同的装液量.经过7 d的摇瓶培养,过滤发酵液,得到菌丝体和粗酶液.再通过测定菌丝体烘干后的生物量,以及测定粗酶液中多酚氧化酶和漆酶活性,得出了:装液量为100 mL,菌丝体烘干生物量明显大于其他装液量;装液量为140 mL,有利于多酚氧化酶的分泌,酶的活力较强,并且其活力随装液量的递增而变强.装液量为100mL,有利于漆酶的分泌,酶的活力较强,不同装液量的菌丝生长都在第6天出现了高峰期,其中以装液量为100mL/250mL时,其菌丝球数量较多.     

花生多胺氧化酶的组织化学定位及显微拍摄

报告了花生幼苗（苗龄为６ｄ）中多胺氧化酶的组织化学定位，并就该酶定位研究中的摄影问题提出了几点看法     

为害小麦新害虫——显脉污灯蛾Spilarctia bisecta Leech (Lepidoptera: Arctiidae)

小麦是我国三大粮食作物之一, 其在生产过程中受到多种害虫为害;在调查重庆市潼南区小麦病虫害过程中新发现一种鳞翅目害虫为害小麦, 对其进行形态学及细胞色素氧化酶Ⅰ亚基(cytochrome oxidase Ⅰ, COⅠ)基因序列鉴定, 确定其为显脉污灯蛾Spilarctia bisecta Leech。污灯蛾属中有多种为害农作物的害虫, 但显脉污灯蛾在中国还未有为害小麦的确切报道, 这一发现提醒我们应当注意小麦和其他禾本科作物上的潜在害虫。     

油茶籽饼多酚的乙醇提取工艺优化研究

研究了油茶籽饼多酚的乙醇提取优化工艺,将正交试验设计方法和BP人工神经网络分析方法相结合,充分挖掘正交试验数据信息,通过仿真模拟和优化,获得油茶籽饼多酚的乙醇较优提取工艺条件:乙醇浓度为60%,提取时间为3.5 h,提取温度为70℃,料液比为1∶15。     

可可活性成分的研究概况

概述可可中的多酚类化合物、脂类化合物、蛋白质及膳食纤维等的活性成分，及其分析方法与生理功能的研究现状。     

STS标记在扬麦158×淮麦18F_4群体中的应用及其与PPO活性的关系

小麦籽粒中的多酚氧化酶活性是导致酶促褐变的主要因素.选育低多酚氧化酶活性的品种是改良面制食品外观品质的重要途径之一.本研究利用位于小麦2A和2D染色体上PPO基因分子标记PPO18和STS01,对扬麦158×淮麦18组合的300个F4代分离株系进行PCR扩增,说明不同带型与PPO活性的相关性.结果表明用PP018扩增的300个分离株系中有59个扩增出876 bp(2aaa型)的目标片段,其活性均值为82.01;46个同时扩增出685 bp和876 bp的目标片段(2Aab型)其活性均值为163.41;其余195个扩增出685 bp的目标片段(2Abb型)其活性均值为233.73.方差分析表明三者的PPO活性差异达到极显著水平,其中基因型为2Aaa型的PPO活性值明显低于2Abb型;PPO18在本试验群体中对PPO活性的决定系数为66.61%;用STS01扩增的300个株系中都扩增出了560bp的片段,群体间没有差异.文中说明了两对引物在该群体中的效应及其与PPO活性的关系.