植物春化特性及春化作用机理

春化作用是某些高等植物成花转变的重要环节,被认为是植物在低温诱导下促使其相关基因的表达,从而导致生理状态转变的一种受遗传控制的生理过程。本文对植物春化反应特性、春化作用的生理生化特性及春化作用的分子生物学等方面的研究进展进行了概述,并对春化研究中的问题进行了分析和展望。     

植物春化特性及春化作用机理

春化作用是某些高等植物成花转变的重要环节,被认为是植物在低温诱导下促使其相关基因的表达,从而导致生理状态转变的一种受遗传控制的生理过程.本文对植物春化反应特性、春化作用的生理生化特性及春化作用的分子生物学等方面的研究进展进行了概述,并对春化研究中的问题进行了分析和展望.     

冬小麦春化作用相关cDNA克隆Vrc79的分子克隆

在低温需求型植物的发育过程中,春化作用是诱导植物成花的必要因子。在冬小麦春化进程中存在着一个核酸代谢的关键期,为了探讨春化作用的分子机理,以不春化及脱春化的冬小麦京冬1号（Ｔｒｉｔｉｃｕｍ　ａｅｓｔｉｖｕｍＬ．ｃｖ．Ｊｉｎｄｏｎｇ　Ｎｏ．１）胚芽的ｍＲＮＡ为对照,通过减法杂交构建了富集冬小麦春化相关基因的ｃＤＮＡ文库,经过差异筛选分离到了一个仅在春化２１ｄ这一关键期表达,而在不春化、春化４ｄ、脱春化不表达的春化相关。ｃＤＮＡ克隆Ｖｒｃ７９。Ｎｏｒｔｈｅｍ杂交及同源性分析表明它是一个在植物中新发现的不同于低温胁迫诱导基因的春化特异克隆,其对春化需求型植物的成花诱导可能起重要的调控作用。     

Expression Patterns of a Vernalization-related Genes Responding to Jasmonate

茉莉酸诱导的春化相关基因表达模式 徐云远 种康* 许智宏* 谭克辉 （中国科学院植物研究所资源植物分子与发育生物学研究中心,北京100093）     

FLC基因表达在植物春化过程中的作用

在对以往有关不同开花途径研究简要总结的基础上综述了FLC基因在春化过程中的作用。近期以拟南芥不同生态型和突变体为模式的研究结果表明基因FLC可能是春化反应的关键基因。研究发现 ,FLC的表达水平与植株低温处理的时间呈数量关系 ,低温处理时间越长 ,FLC的表达越弱 ,去甲基化也可能对FLC起负调控的作用。同时FLC也存在于自主开花途径中 ,与其他基因共同作用以调节植株开花时间。而FLC的表达对开花起抑制作用。一系列研究表明 ,春化的低温作用可能在于相关基因的去甲基化 ,消除了FLC对开花的抑制作用 ,从而解除赤霉素合成途径的封锁最终导致植株在一定时期开花。     

高等植物春化作用研究进展

环境因子（ 低温诱导或称春化作用） 在高等植物的生长发育调控中起着重要作用。本文就近年来春化作用诱导的开花启动研究领域中的进展从春化过程中的多步骤性、成花决定过程控制的多途径性、接受春化刺激的位置与分化启动的关系、以及春化作用的分子机理等几个方面进行了简要综述。并对春化相关基因克隆方面的进展进行了分析和综述     

FLC基因表达在植物春化过程中的作用

在对以往有关不同开花途径研究简要总结的基础上综述了FLC基因在春化过程中 的作用。近期以拟南芥不同生态型和突变体为模式的研究结果表明基因FLC可能是春化反应的关键基因。研究发现,FLC的表达水平与植株低温处理的时间呈数量关系,低温处理时间越长,FLC的表达越弱,去甲基化也可能对FLC起负调控的作用。同时FLC也存在于自主开花途径中,与其他基因共同作用以调节植株开花时间。而FLC的表达对开花起抑制作用。一系列研究表明,春化的低温作用可能在于相关基因的去甲基化,消除了FLC对开花的抑制作用,从而解除赤霉素合成途径的封锁最终导致植株在一定时期开花。     

春化作用相关基因FLC的研究进展

拟南芥春化作用相关基因FLOWERING LOCUS C（FLC）属于MADS盒基因,它编码的蛋白转录因子对开花具抑制作用。春化作用通过负调控FLC的转录及蛋白表达水平,促进拟南芥的某些晚花生态型和晚花突变体开花。主要介绍了FLC基因在春化途径中的关键作用,及其春化作用通过FLC基因与其它开花途径相联系等内容。     

田鼠婚配制度的神经内分泌基础

作为繁殖行为的一种表现形式,婚配制度是通过长期进化而形成的,具有种属特异性及可遗传性。因此,不同的婚配制度具有不同的生理基础。这种生理基础由3级结构组成：神经直接启动并维持繁殖行为;激素或通过诱导特异神经通路的发育或直接激活神经传导影响繁殖行为;基因则可能是通过调节激素的代谢和作用方式来控制与繁殖行为相关的神经系统。田鼠脑中涉及婚配制度的区域集中在视前区中部（MPOA）,腹被盖区（VTA）,膈部及纹状体端部。起作用的激素主要是催产素（OT）和后叶加压素（AVP）。导致田鼠形成不同婚配制度的最终原因可能是这两种激素受体基因上的差异。受体基因调控区的启动子序列存在变异,导致脑中受体基因在表达区域上的差异,进而使激素激活不同的神经通路,产生不同的繁殖行为及婚配制度。     

小麦春化相关基因的分子克隆与功能分析

小麦春化相关基因的分子克隆与功能分析@种康$中国科学院植物研究所!北京100093@许智宏$中国科学院植物研究所!北京100093@谭克辉$中国科学院植物研究所!北京100093小麦;;基因;;分子克隆     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).