长白山地区蜜环菌属真菌资源

蜜环菌属Armillaria真菌是长白山地区代表性野生菌,具有重要的食药用价值。本研究采用样方调查和随机踏查相结合的方法对该地区蜜环菌属物种展开资源调查和种类鉴定,结果表明,长白山地区蜜环菌有5种,即北方蜜环菌Armillaira borealis、法国蜜环菌A. gallica、黄小蜜环菌A. cepistipes、芥黄蜜环菌A. sinapina以及Armillaira sp.,其中北方蜜环菌为吉林省新记录种,法国蜜环菌为该地区的优势物种。多样性分析结果表明,在阔叶林、针阔混交林、针叶林3种林型中,针阔混交林中蜜环菌属α多样性指数相对较高,说明针阔混交林的物种丰富度最高。本研究为蜜环菌属资源的开发和利用提供理论基础和实践依据。     

猪苓与天麻共生蜜环菌类群的比较

猪苓和天麻都是传统中草药,具有很高的药用价值。它们的生长都离不开蜜环菌,蜜环菌可以为其生长提供营养。对于猪苓和天麻共生的蜜环菌种类是否有一定的异同,目前尚未有相应的报道。本研究在前期完成的从全国11个省份收集野生猪苓菌核,分离得到47株蜜环菌以及ITS、β-tubulin和elongation factor-1 alpha 3种序列的基础上,与文献报道的天麻共生蜜环菌的序列进行比较,并构建系统发育树,结果显示猪苓和天麻共生的蜜环菌共分为10个clade,其中和猪苓共生的蜜环菌有6个clade,和天麻共生的蜜环菌有7个clade,有3个clade的蜜环菌既可以和天麻共生,也可和猪苓共生。在这3个共同类群中,菌株来自于陕西、山西、吉林、黑龙江、贵州、甘肃、四川几个省份。西藏、云南等地的蜜环菌则具有较高的专一性。本研究从系统发育角度明确了猪苓和天麻共生蜜环菌的异同,该结果可为猪苓和天麻栽培过程中蜜环菌种类的选择提供一定的理论依据。     

蜜环菌分纯及深层液体培养条件初探

（Ａｒｍｉｌｌｅｒｉｅｌｌａ ｍｅｌｌｅａ）是一种有名的药用覃菌,对人类大有裨益。笔者对从云南采集的蜜环菌Ｓｈ－１４进行分离纯化,并对蜜环菌固体培养的营养、温度、水份等进行了研究。同时对蜜环菌深层液培养的一级种子及发酵培养基对蜜环菌菌丝体生长影响作了探讨。通过实验获得最佳一级种子培养基及发酵培养基。     

伞形多孔菌菌核(猪苓)共生蜜环菌培养特性的比较研究

蜜环菌能为药用真菌伞形多孔菌菌核(猪苓)的生长提供营养,其自身也是一种重要的食药用真菌。筛选优良的蜜环菌菌株既可用于猪苓的栽培生产,也可为蜜环菌的进一步开发提供参考。本研究将从野生猪苓中分离得到的47株蜜环菌菌株划分形态型,选取12个代表性菌株进行液体培养,研究菌丝体多糖含量,以及发酵液中的羧甲基纤维素酶(CMC酶)、木聚糖酶、漆酶的活性变化。结果显示,蜜环菌菌株M8-3生长较快,生物量累积最高,3种关键酶的活性也较高,为较优质菌株,可用于猪苓的栽培实验;菌株M3和M8-3菌丝体多糖含量较高,可作为蜜环菌开发利用的候选菌株。     

蜜环菌生物种及鉴定方法研究进展

蜜环菌属真菌是一类重要的大型真菌,在全世界范围广泛分布。该属中有些种是重要的林木病原菌,有些种则具有很高的食药用价值。由于蜜环菌属真菌形态差异并不明显,缺乏分类特征,该属的分类和鉴定一直是大型真菌的研究热点。自从生物种的概念提出之后,蜜环菌的分类鉴定取得了突破性的进展,目前全球范围内已报道的蜜环菌生物种近40种;而对蜜环菌生物种的鉴定方法则包括了最初的形态学鉴定以及近些年发展起来的分子生物学鉴定方法。本文对当前世界范围内已经鉴定的蜜环菌生物种进行了梳理,并对蜜环菌生物种的鉴定方法的研究进展进行了综述,旨在为蜜环菌的研究提供参考。     

天麻栽培用蜜环菌的遗传多样性、生长和水解酶

蜜环菌Armillaria是一种广泛分布的担子菌,是栽培中药天麻所必须的共生菌。为揭示我国天麻栽培用和鄂西地区部分野生蜜环菌资源的遗传多样性和生物学特性,本文收集了9个省市EF-1-α的19个蜜环菌商品菌株和鄂西地区20株野生蜜环菌菌株,以IGS、ITS和elongation factor-1-alpha（EF-1-α）为分子标记对这些菌株进行系统发育与遗传多样性分析,并对影响与天麻共生的生物学特性（菌索发育和胞外水解酶活性）进行对比研究。结果表明,这19株蜜环菌商品菌株分别归属于2个clade。其中,有18个菌株聚在cladeⅢ,说明不同来源的蜜环菌商品菌株之间系统发育关系很近;通过对蜜环菌的系统发育、菌索生长以及胞外水解酶活性的研究,总体上商品种优于鄂西的野生蜜环菌生物种。从鄂西野生蜜环菌中筛选出4个具有潜在栽培价值的菌株。本研究为天麻栽培生产中蜜环菌菌种的选择提供参考。     

天麻与蜜环菌的关系

天麻(Gastrodia elata Bl.)除开花结实期外,蜜环菌对天麻幼苗的形成、营养器官的更新以及营养生长转向生殖生长,都起决定性的作用。块茎潜伏芽的萌动及其后的发育程度也完全由蜜环菌的侵染部位和程度所决定,不存在内在的顺序性。观察了蜜环菌对天麻侵染的详细过程,并发现有正常生理侵染和病理侵染两种状况。病理侵染的突出表现是入侵的菌索可冲破消化层而瓦解深层的组织,致使新生块茎生长不良。不仅块茎可以同化蜜环菌,营养茎也起同化蜜环菌的作用。幼苗期营养茎是唯一的同化器官;以后的营养生长期,它仍占重要地位;只是进入生殖生长期以后,营养茎才居于次要地位。正生长的块茎不能同化蜜环菌,只有经过越冬以后才能执行同化器官的作用。     

天麻矿物质吸收及其营养机理探讨

探讨了天麻吸收矿物质过程和天麻的营养机理。研究蜜环菌在天麻的金属元素、非金属元素吸收中起的作用, 阐明天麻的有机营养吸收过程。提出了天麻吸收非金属元素的两个途径,分析了天麻吸收金属元素的“泵”的作用机理。指出了天麻蜜环菌之间的游离氨基酸特别是天冬氨酸和谷氨酸的交流是天麻和蜜环菌生长发育的关键。     

天麻的第二营养来源研究

用同位素32P、15N、86Rb标记技术,证实天麻除必需由蜜环菌获得营养外,还能从土壤养分中得到补充营养,可称为第二营养来源。土壤养分(肥料)可通过蜜环菌或天麻表皮进入天麻体内(参与天麻代谢生理活动),可能影响天麻和蜜环菌的关系和天麻生长,因此研究天麻施肥技术和对产量、质量的影响是很有意义的。     

我国蜜环菌分类单元间菌索的相互作用

蜜环菌菌索是天麻生长的主要营养来源,而蜜环菌生物种菌索之间可能存在种间相互作用,因此天麻栽培时蜜环菌种的混用可能对天麻的产量产生影响。为揭示我国蜜环菌分类单元间菌索的相互作用,以我国8个蜜环菌分类单元为研究对象,通过研究其共同培养时整体及单侧菌索的生长速率和单位长度内生长尖端个数来研究其菌索间的作用特性。结果表明：两者间相互拮抗的有CBS D-CBS F;仅有一个蜜环菌菌索未受到影响或受到协同作用的有：CBS A-CBS H中的CBS A、CBS F-CBS J中的CBS J、CBS A-CBS F中的CBS A、CBS A-CBS N中的CBS A、CBS F-CBS M中的CBS M、CBS J-CBS M中的CBS M、CBS B-CBS J中的CBS B;组合中两种蜜环菌菌索靠近侧协同生长的有：CBS A-CBS M;组合中对两者靠近的区域具有优势的有：CBS A-CBS B中的CBS B、CBS A-CBS J中的CBS J、CBS B-CBS F中的CBS F、CBS D-CBS H中的CBS H、CBS D-CBS N中的CBS N和CBS F-CBS M中的CBS F。本研究的开展为我国蜜环菌的鉴定、天麻栽培用蜜环菌种的选用提供理论指导。     

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.