RNA原位杂交技术及其在植物基因表达研究中的应用

原位杂交 ( In situ Hybridization)是一种在细胞水平上研究基因表达调控的最直接有效的分子生物学技术。这一技术最初应用于动物染色体上的基因物理定位 〔1〕和特定 m RNA在组织中的空间定位〔2〕,后来又作为诊断工具检测感染病毒的细胞 〔3〕。到 80年代后期 ,原位杂交技术开始应用于植物基因表达调控的研究 〔4～ 6〕。植物基因的时空表达研究是探讨植物生长发育机制的重要手段。由于 RNA原位杂交技术能够精确确定基因表达的时空分布 ,而得到了越来越广泛的应用 ;从营养器官生长发育〔7～ 9〕、生殖器官生长发育〔10～ 13〕、自交不…     

中国榆科植物系统分类研究综述

榆科 (Ulmaceae)植物 1 6属近 2 30种 〔1〕,广布于世界温带及热带地区 ,主产北温带 〔2～ 4〕。榆科具高度稳定性和适应性 ,现存的各属、组及主要种早于新世即已存在。据化石孢粉学分析 ,第三纪时 ,我国东北、华北及西北就有榆科分布。我国现共有榆科植物 8属 ,分别为榆属 (Ulmus) ,朴属 (Celtis) ,糙叶树属(Aphananthe) ,山黄麻属 (Trema) ,白颜树属 (Gironniera) ,榉属 (Zelkova) ,刺榆属 (H emiptelea)和青檀属(Pteroceltis) ,46种 1 0变种 ,分布遍及全国 〔1〕。Mirbel最初描述榆科时 ,只有榆属和朴属 〔5〕,以后逐渐增多。但自此…     

淹涝胁迫对水稻叶鞘和叶片中淀粉粒分布的影响

淹涝是世界上当前所面临的最严重自然灾害之一,尤其是近几年来,淹涝给我国的农业生产带来了巨大损失,全国平均每年受涝面积814万hm2,其中成灾面积448万hm2,损失粮食约28亿kg〔1〕。水稻是我国的主要粮食作物,并且分布于淹涝易发生的南方多雨潮湿地区和北方低洼地带,淹涝对水稻产量影响极大,因此,研究淹涝胁迫对水稻的伤害及水稻的耐淹机制越来越受到人们的重视〔2〕。淹涝对植物的伤害并非是因为水分过多而造成的直接伤害,而是由于淹涝造成的次生胁迫,其中最严重的是缺氧。在缺氧条件下,细胞中的碳水化合物代谢途径改变,对植物的生长和发育…     

植物叶片衰老过程中的基因表达与调控

衰老是一种器官或组织逐步走向功能衰退和死亡的变化过程〔１〕。它除了代表器官或组织生命周期的终结之外,在发育生物学上也有着重要的意义。叶片的衰老是植物的一个重要发育阶段。在这段时期内,植物在成熟叶片内积累的物质,包括大量的氮、碳有机化合物和矿物质,将被分解并运送至植物其它生长旺盛的部分,其中大部分被转移到种子内,为下一代的生长做好准备〔１１〕。对于产生种子的作物,包括绝大多数农作物,这种转移使营养重新分配,对植株保持正常的生长发育与繁殖是十分必要的〔３〕。衰老过程中,叶片细胞在组成成分上有很大的变…     

世界著名观赏树种——珙桐

珙桐(Davidia involucrata Baill.),英文称为“Dove-tree”(鸽子树),是特产于我国的单型属(Monotypic genus)植物;属于种子植物,珙桐科(Davidiaceae),珙桐属(Davidia)的落叶乔木。原属紫树科(Nyssaceae),珙桐属,因与紫树科另外两属特征上有显著的不同,现已独立成珙桐科。珙桐只一种,并有一变种:光叶珙桐[Davidia involucrata Baill. vat. vilmoriniana(Dode)Hemsl.],特产于湖北省神农架山地。     

土壤氮素与光照对盆栽珙桐幼苗光合参数的影响

珙桐是我国特有珍稀保护物种,在植物系统发育和地史变迁研究上有很高的学术地位,国内外学者进行了大量的研究。以濒危植物珙桐(Davidia involucrate)一年生幼苗为试验材料,通过控制土壤氮素含量与光照的方法,研究了不同土壤氮素含量(0mg、200mg、400mg、600mg、800mg)及是否遮光对珙桐幼苗生长和光合参数的影响,探讨土壤氮素及光照对珙桐幼苗生长的影响。结果表明:1)高氮素水平可以减缓在非适生环境下生长的珙桐幼苗光合速率的降低;2)适宜的直射光照可能对珙桐等喜阴植物的幼苗的生长是有利的;3)氮素对由遮光引起的光合参数的降低有补偿作用,但仍无法完全抵消由于遮光所引起的净光合速率的降低。     

活化石——珙桐

珙桐,也叫鸽子树,是我国特有的稀珍植物,也是世界著名的观尝树种。因为它开花时,两个洁白的大苞片象鸽子栖息于枝头,所以得此美名。珙桐是植物中的“活化石”之一。大约在数百万年     

荷叶铁线蕨等位酶分析初步研究

荷叶铁线蕨 ( Adiantum reniforme var.sinense)是铁线蕨科铁线蕨属肾叶铁线蕨的一个变种〔1〕,分布于重庆市万县、石柱等县的沿江近 1 0 0 km长的狭长地段 ,分布高度局限于海拔 80～ 430 m之间 〔2〕。受其自身生物学、生态学习性的局限和人为的破坏 ,该物种正濒于灭绝的边缘。三峡工程修建后 ,库区内1 75m线以下的地区将被淹没 ,将更加剧该物种的濒危程度。为了挽救这一物种已经采取了许多措施 ,迁地保护是其中的重要措施之一 ,中国科学院武汉植物研究所在这一方面已经做了一些工作 〔3～ 5〕。为了有效地实施迁地保护 ,保存该物种的大部…     

珙桐生物学研究进展

珙桐是我国特有的珍稀濒危植物,国内外学者对其进行了大量研究。目前对珙桐的研究主要集中在珙桐的形态描述、地理分布、种群和群落生态以及引种繁殖等方面。而对其发育生物学,特别生殖过程等研究较少。即便是研究较多的生态学方面也仅仅局限在宏观描述方面,未形成一个完整的系统。今后有必要对这些方面进行研究以更好的保护这一物种资源。     

铅锌矿区土壤和植物重金属污染调查分析

对有色金属矿区土壤和植物重金属污染状况调查结果表明,由于遭受尾矿砂及矿毒水污染,矿区土壤极端贫瘠,土壤中Pb、Cd、Zn和Cu含量分别达764.74、4.10、372.75和95.57 mg.kg-1,重金属污染较为严重。在矿区周边有9种优势植物能够在污染土壤上定居,对Cu、Cd、Pb和Zn 4种重金属元素均有不同程度的积累,积累量均未达到超累积植物所规定的临界含量。其中的野菊花〔Dendranthema indicum(L.)Des Mou l.〕、旋鳞莎草〔Cyperusm ichelianus(L.)L ink〕、五节芒〔M iscanthus floridulus(Lab ill.)W arb.ex Schum.et Laut.〕3种植物地上部生物量较大且对某些重金属向地上部转运能力较强,对重金属污染土壤有一定的修复潜力。     

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.