台闽苣苔（苦苣苔科）幼苗的发育式样及其意义

为解决台闽苣苔族 (Titanotricheae)这一单种族的科级系统位置 ,通过扫描电镜观察了台闽苣苔 (Titan otrichumoldhamii (Hemsl.)Solereder)植物的种子发芽和幼苗发育过程。随着下胚轴的向下伸长 ,两个子叶开始不明显的异率生长 ,其中一片子叶略大于另一片子叶。但两片子叶均正常发育并位于同一高度。当真叶发出后 ,两片子叶几乎等大 ,并且两个子叶柄等长。在幼苗生长期间 ,随着子叶的生长 ,胚芽也正常萌发出茎的顶芽。顶芽持续进行顶端生长产生交互对生的真叶。这一幼苗生长式样和苦苣苔亚科其他类群的仅一片子叶发育与胚芽被抑制的幼苗生长式样有明显区别。考虑到台闽苣苔植物在总状花序的上部大量簇生无性珠芽 ,并落地迅速生长出新的植株这一在苦苣苔科中独特的无性繁殖方式及相关性状 ,台闽苣苔族可能较早地从苦苣苔亚科中分化出来 ,并在繁殖体的功能进化方面和其他类群发生歧化进而获得独特的无性繁殖方式。台闽苣苔族在系统发育上应该被认为是其他苦苣苔亚科类群的姊妹群 ,应当提升为亚科等级。     

异叶苣苔属地上茎的生长式样及其系统发育意义

对异叶苣苔属植物地上茎形态发生过程的观察旨在揭示该属地上茎的生长式样。该研究发现异 叶苣苔属植物地上茎的生长式样并不是以往所认为的简单顶端生长。该属植物的顶芽已完全受到抑制。其地上茎实际上是萌发于小型叶叶腋的侧芽替代顶芽生长所形成的各级侧枝系统,即合轴分枝系统。异叶苣苔属植物地上茎的不分枝情况是位于大型叶叶腋的腋芽受到抑制所致,纯粹是一种次生现象,并不是尖舌苣苔族植物原始祖先的孑遗性状。尖舌苣苔族其他属植物地上茎的生长式样并不均是从异叶苣苔属植物的生长式样演化而来。出蕊苣苔属和异叶苣苔属植物地上茎的生长式样可能来自同一个不太远的祖先,但已经向着不同的方向演化。独叶苣苔属植物复杂的圆锥状对花聚伞花序并非从异叶苣苔属地上茎上部,即生殖生长部分退化而来,乃幼态成熟的复化过程所致。尖舌苣苔属的总状花序可能更接近尖舌苣苔族的原始祖先类型。     

紫茎泽兰对五种苦苣苔科植物化感作用的初步研究

紫茎泽兰（Eupatorium adenophorum）为菊科一种入侵性极强的外来杂草, 现已在我国西南部地区蔓延生长, 并侵入多种苦苣苔科植物的生境。中国苦苣苔科植物均已收入《中国物种红色名录》, 其中部分已被列为国家重点保护物种。为了解紫茎泽兰对本土苦苣苔科植物生长的影响, 作者分别采用其根、茎、叶水提液(8%)对3属5种苦苣苔科植物, 即刺齿唇柱苣苔（Chirita spinulosa）、荔波唇柱苣苔（C. liboensis）、烟叶唇柱苣苔（C. heterotricha）、芒毛苣苔（Aeschynanthus acuminatus）和台闽苣苔（Titanotrichum oldhamii）的幼苗进行处理。结果表明, 紫茎泽兰叶水提液对刺齿唇柱苣苔、荔波唇柱苣苔和烟叶唇柱苣苔均有不同程度的化感作用, 其中对刺齿唇柱苣苔的化感作用最为明显, 当叶水提液在培养基中的浓度为2.4%、3.2%和4.0%时, 刺齿唇柱苣苔幼苗的生长完全受到抑制。紫茎泽兰的茎水提液对台闽苣苔有一定程度的化感作用, 当提取液在培养基中的浓度为1.6%时, 对台闽苣苔幼苗生长的抑制效应达到40%。紫茎泽兰叶和茎水提液对芒毛苣苔幼苗生长无明显的化感作用, 紫茎泽兰根水提液对5种苦苣苔科植物也均无显著影响。由此可知, 紫茎泽兰对唇柱苣苔属和台闽苣苔属的植物有一定的化感作用, 而对于芒毛苣苔属无明显的影响。分析结果显示, 紫茎泽兰对岩生苦苣苔科种类要比附生于树上的近缘种化感作用更为明显。     

rDNA片段的序列分析在苦苣苔亚科系统学研究中的应用

本文测定了苦苣苔亚科4族、5属、5种植物的核糖体DNA中的内转录间隔区(ITS)序列及5．8s rRNA基因的3′端序列。这几种苦苣苔亚科植物的ITS-1的长度范围为234～258 bp,ITS-2的长度范 围为218～246bp。Whytockia bijieensis的ITS-1(258bP)和ITS-2(218 bp)在长度、序列及GC含量上 均与其它几个种有较大差异,其代表的尖舌苣苔族可能很早就自苦苣苔亚科的祖先沿单独的一个分支 演化。以w．bijieensis作为功能性外类群,运用PAUP软件分析仅得到一个最简约树。在简约树上, Cyrtandra umbelliferm、Briggsia longipes和Anna mollifolia形成一个单系群,bootstrap分析对该分支的 支持强度达97％,Chirita crasslfolia位于该分支的基部。由于系统树上Cyrtandra umbellifera代表的 浆果苣苔族和Anna mollifolid代表的芒毛苣苔族均起源于长蒴苣苔族,结合这3个族在形态上存在过渡系列,建议将浆果苣苔族和芒毛苣苔族均并入长蒴苣苔族。     

rDNA片段的序列分析在苦苣苔亚科系统学研究中的应用

本文测定了苦苣苔亚科4族、5属、5种植物的核糖体DNA中的内转录间隔区(ITS)序列及5．8s rRNA基因的3′端序列。这几种苦苣苔亚科植物的ITS-1的长度范围为234～258 bp,ITS-2的长度范 围为218～246bp。Whytockia bijieensis的ITS-1(258bP)和ITS-2(218 bp)在长度、序列及GC含量上 均与其它几个种有较大差异,其代表的尖舌苣苔族可能很早就自苦苣苔亚科的祖先沿单独的一个分支 演化。以w．bijieensis作为功能性外类群,运用PAUP软件分析仅得到一个最简约树。在简约树上, Cyrtandra umbelliferm、Briggsia longipes和Anna mollifolia形成一个单系群,bootstrap分析对该分支的 支持强度达97％,Chirita crasslfolia位于该分支的基部。由于系统树上Cyrtandra umbellifera代表的 浆果苣苔族和Anna mollifolid代表的芒毛苣苔族均起源于长蒴苣苔族,结合这3个族在形态上存在过渡系列,建议将浆果苣苔族和芒毛苣苔族均并入长蒴苣苔族。     

单种属弥勒苣苔属系统位置研究 基于分子和细胞学数据

弥勒苣苔属是苦苣苔科的单种属,仅分布于中国西南部。为探讨弥勒苣苔在苦苣苔亚科中的系统位置,我们选择了苦苣苔亚科116个类群,外类群为苦苣苔亚科以外的7个物种。用最大简约法（MP）和贝叶斯分析（BI）,对以上类群的核基因ITS以及两个叶绿体基因trnL-F、atpB-rbcL数据进行了独立和联合分析。在三个片段联合分析的结果中,弥勒苣苔与马铃苣苔属、后蕊苣苔属、金盏苣苔属、直瓣苣苔属以及川鄂粗筒苣苔构成一个强烈支持的分枝。MP树中,此分枝为并系,而在BI分析中,弥勒苣苔与川鄂粗筒苣苔、直瓣苣苔属互为姐妹类群。同时,第一次报道了弥勒苣苔的染色体数目（2n=34）。根据前人报道,马铃苣苔属、后蕊苣苔属、粗筒苣苔属和直瓣苣苔属的染色体数目同为2n=34,这进一步支持我们的分子系统发育分析。     

单种属弥勒苣苔属系统位置研究：基于分子和细胞学数据

弥勒苣苔属是苦苣苔科的单种属,仅分布于中国西南部。为探讨弥勒苣苔在苦苣苔亚科中的系统位置,我们选择了苦苣苔亚科116个类群,外类群为苦苣苔亚科以外的7个物种。用最大简约法（MP）和贝叶斯分析（BI）,对以上类群的核基因ITS以及两个叶绿体基因trnL-F、atpB-rbcL数据进行了独立和联合分析。在三个片段联合分析的结果中,弥勒苣苔与马铃苣苔属、后蕊苣苔属、金盏苣苔属、直瓣苣苔属以及川鄂粗筒苣苔构成一个强烈支持的分枝。MP树中,此分枝为并系,而在BI分析中,弥勒苣苔与川鄂粗筒苣苔、直瓣苣苔属互为姐妹类群。同时,第一次报道了弥勒苣苔的染色体数目（2n=34）。根据前人报道,马铃苣苔属、后蕊苣苔属、粗筒苣苔属和直瓣苣苔属的染色体数目同为2n=34,这进一步支持我们的分子系统发育分析。     

金盏苣苔属(苦苣苔科)的第二次校订

金盏苣苔属(Isometrum Craib)属于苦苣苔亚科(Cyrtandroideae)长蒴苣苔族(Didymocarpcae),是由W.G.Craib 1919根据I.farreri Craib建立的,同年他又把Didissandra glandulosa Batalin置于该属,1960年B.L.Burtt又把Didi-sandra Clarke中的4个种(即:D.prumuliflora Batalim,D.giraldii Diels,D.fargesii Franch.和D.leucantha Diels)移入该属。作者在编写中国植物志苦苣苔     

台闽苣苔(苦苣苔科)花部器官的形态发生

在扫描电镜下对台闽苣苔 (T. oldhamii (Hemsl.) Solereder)进行了花部器官形态发生的观察,为探索该类群的个体发育、类群间的系统发育关系和进化趋势提供依据.研究发现该属植物萼片、花冠和雄蕊发生式样均为五数花类型,它们各自来源于花原基上分化出来的萼片原基、花冠原基和雄蕊原基;花冠与雄蕊的两侧对称性与花冠上唇生长稍快和退化雄蕊原基发育迟滞相关;萼片原基的发生和发育的顺序是不一致的:萼片原基发生的式样为近轴中原基-远轴2原基-2侧原基,发育式样则为近轴中萼片-2侧萼片-远轴2萼片,花蕾时为镊合状排列.花冠裂片原基的发生和发育式样是一致的,即远轴中裂原基(下唇中裂片)-远轴2侧裂原基(下唇2侧裂片)-近轴2裂原基(上唇2裂片).花蕾期卷迭式为覆瓦状排列,从外向内:下唇中裂片-下唇2侧裂片-上唇2裂片或下唇2侧裂片-上唇2裂片-下唇中裂片.雄蕊原基与花冠裂片原基互生,前方雄蕊原基在发生上稍迟于后方雄蕊原基,后者与退化雄蕊原基几乎同时发生,但较小,并与近轴心皮(或柱头上唇)对生.将该属与玄参科(Scrophulariaceae)的地黄属( Rehmannia )、苦苣苔科(Gesneriaceae)的异叶苣苔属( Whytockia)和尖舌苣苔属(Rhynchoglossum )的花部器官比较发现,这四个属在这方面呈现出多样性和交叉.过去一直按子房室数和胎座类型划分玄参科(子房2室、中轴胎座)和苦苣苔科(子房1室、侧膜胎座)这一做法受到了质疑.     

台闽苣苔（苦苣苔科）花部器官的形态发生

在扫描电镜下对台闽苣苔 (T .oldhamii (Hemsl.)Solereder)进行了花部器官形态发生的观察 ,为探索该类群的个体发育、类群间的系统发育关系和进化趋势提供依据。研究发现该属植物萼片、花冠和雄蕊发生式样均为五数花类型 ,它们各自来源于花原基上分化出来的萼片原基、花冠原基和雄蕊原基 ;花冠与雄蕊的两侧对称性与花冠上唇生长稍快和退化雄蕊原基发育迟滞相关 ;萼片原基的发生和发育的顺序是不一致的 :萼片原基发生的式样为近轴中原基—远轴 2原基— 2侧原基 ,发育式样则为近轴中萼片— 2侧萼片—远轴 2萼片 ,花蕾时为镊合状排列。花冠裂片原基的发生和发育式样是一致的 ,即远轴中裂原基 (下唇中裂片 )—远轴 2侧裂原基 (下唇 2侧裂片 )—近轴 2裂原基 (上唇 2裂片 )。花蕾期卷迭式为覆瓦状排列 ,从外向内 :下唇中裂片—下唇 2侧裂片—上唇 2裂片或下唇 2侧裂片—上唇 2裂片—下唇中裂片。雄蕊原基与花冠裂片原基互生 ,前方雄蕊原基在发生上稍迟于后方雄蕊原基 ,后者与退化雄蕊原基几乎同时发生 ,但较小 ,并与近轴心皮 (或柱头上唇 )对生。将该属与玄参科 (Scrophulari aceae)的地黄属 (Rehmannia)、苦苣苔科 (Gesneriaceae)的异叶苣苔属 (Whytockia)和尖舌苣苔属 (Rhynchoglossum)的花部器官比较发现     

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     

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.     

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.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

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).     

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.