花生幼叶为外植体的植株再生系统的建立

本文报道利用花生成熟胚幼叶为外植体获得高频植株再生的方法,为花生转基因提供有效的受体系统。通过诱导培养基TDZ、BA、NAA的浓度以及种子萌发时间、继代培养基种类五个因素不同水平的正交试验,筛选出了分化高频发生的最佳组合为：MS培养基中应含有TDZ 1.0 μmol/L、BA 0.4 μmol/L、NAA 5.0 μmol/L,种子萌发4 d,继代培养基为MS0。本研究表明,五因素中诱导培养基TDZ浓度为诱导花生幼叶分化的主要影响因素,其次为继代培养基、种子萌发时间,而诱导培养基中BA和NAA的浓度作用较小。试管苗生根后移栽田间,可正常开花结果。     

不同激素对花生离体分化的影响

对TDZ和2,4-D等激素在花生成熟胚外植体分化中的影响进行了研究.结果表明,花生成熟胚3～5 d龄实生苗的幼叶和胚轴在低浓度TDZ的诱导下,可分化产生高频不定芽和少量体细胞胚,转到无激素MS培养基或MS BA 0.5 mg/L NAA 0.4 mg/L的培养基后形成丛生苗.丛生苗分离后转入含1/2 MS(大量元素) IBA 0.4 mg/L的培养基中诱导生根,可形成完整的再生植株.幼叶分化率高于胚轴,但胚轴分化成苗速度快.无菌水浸泡16～24 h的胚轴在5～ 30 mg/L 2,4-D的诱导下,分化产生低频不定芽;而胚叶则产生高频体细胞胚,但畸形较严重.     

南欧丹参的组织培养与快速繁殖(简报)

以南欧丹参种子萌发的无菌苗茎段为材料,在MS＋6IBA1．5mg／L＋NAA0．5mg／L＋GA30．05mg/L培养基上进行不定芽诱导与增殖培养,30d继代一次,繁殖系数为4～6;壮苗与生根培养基为1／2MS＋NAA1．0mg/L＋1BA0．2mg／L。本试验建立了南欧丹参的种苗快速繁殖技术规程。     

贯叶金丝桃组织培养的研究

分别以甘肃天水贯叶金丝桃的幼根、幼茎、幼叶为外植体．在1／2MS培养基上附加各类激素,进行贯叶金丝桃的组培实验。研究发现各外植体的增殖速率由高到低分别为幼茎、幼根、幼叶,且得到贯叶金丝桃组培各阶段的最佳培养基成分。诱导愈伤组织的培养基为1／2MS 1．3～1．6mg／L BA 0．2mg／L NAA;培养基1／2MS 1．3～1．6mg／L BA 0．15mg／L NAA有利于不定芽的形成;诱导不定根的培养基为l／2MS IBA0．5～O．8mg／L 蔗糖2．0％。向1／2MS培养基中添加不同的生长素(IAA,IBA,NAA,2．4-D)．在不同浓度梯度的培养基上进行诱导贯叶金丝桃的愈伤组织及不定根的试验,结果表明：生长素IAA,IBA既可诱导愈伤组织,又可以诱导不定根的产生。生长素NAA,2,4-D可诱导产生愈伤组织,但对不定根的诱导作用较差。     

肯氏相思的组织培养(简报)

1．植物名称肯氏相思（Acaciacunninghamia）2．材料类别茎尖、嫩茎段和叶片3．培养条件基本培养基为MS。（1）诱导愈伤组织培养基为：MS＋6－BA1．0＋NAA0．2,（2）诱导分化培养基为：MS＋6－BA0．5＋NAA0.2,（3）诱导生极培养基为：3／4MS＋NAA0．2,以上激素浓度均为mg／L     

叶子花的组织培养与微繁技术研究

叶子花茎尖、茎段接种在MS附加不同浓度组合的6-BA、IAA、IBA、NAA培养基上可诱导茎尖及腋芽的生长而获得无性系芽,无性系芽茎尖和茎段在MS附加6-BA0．5mg／L,NAA0．05mg／L进行继代培养,一般不形成丛生芽,以茎尖生长和腋芽萌生增殖,增殖系数为2．73;高度大于3cm的增殖芽在1／2 MS附加IAA lmg／L、IBA lmg／L、NAA0．2mg／L培养基上生根率为80．5％,生根苗用“二步法”移栽成活率在97％以上。无性系芽的幼叶、茎段在MS附加6-BA和NAA、2,4-D培养基上能高频产生愈伤组织,但愈伤组织在所试验的所有培养基上均无不定芽或胚状体的分化。     

白刺金琥组织培养研究

以白刺金琥种子无菌播种产生的小球体为外植体,进行愈伤组织诱导和小球分化。结果表明,去除顶端生长点的小球在MS＋6－BA 1.0mg/L NAA 0.1mg/L的培养基中,可由刺座直接产生大量小球体,而切口形成的愈伤组织在6－BA浓度低于4.0mg/L时无法分化小球,当6－BA浓度提高到4．0－6．0mg/L时,亦可分化小球体,但诱导率低且周期长。继代培养在MS＋6－BA0.5L NAA 0.1mg/L培养基中进行,单球在1／2MS加或不加NAA的培养基上均可生根。     

丽格海棠的离体快繁

取丽格海棠幼叶为外植体,在诱导培养基MS＋BA 0．5mg/L NAA 1.0mm/L上培养20d左右,开始分化花芽,培养40d丛生芽长满整个外植体,丛生芽的增殖培养以MS＋BA 0．5mg/L为佳,芽长得大且粗壮,粗壮芽转入无激素的1／2MS生根培养基,生根率达100％。     

中国野生葡萄组织培养研究

对中国野生山葡萄左山—1、左山—2、燕山葡萄燕山—1和秋葡萄平利—7的叶片、叶柄、茎段及单芽茎段进行了离体培养研究。诱导左山—1叶片分化出不定芽的培养基为MS BA 5．0mg／L NAA0．1mg／L,诱导率2．5％;诱导平利—7叶柄分化出不定芽的培养基为MS BA7．0mg／L NAA0．1mg／L,诱导率1．95％;诱导左山—1、燕山—1和平利—7茎段分化出不定芽的培养基与叶柄相同,但诱导率相对较高,分别为8．25％、4．88％和6．49％;应用这一培养基对平利—7、左山—2的单芽茎段进行培养,丛状不定芽的诱导率均为100％。不定芽继代培养基为MS BA0．5mg／L IBA0．2mg／L;生根培养基为1／2MS IBA0．1—0.2mg／L。     

皇冠草叶片外植体的体胚发生和植株再生

PlantletReperationandSomaticEmbryogenesisfromYoungLeavesofEchinodorusosirisXINGDeng－Hui(Departmentofbiology,CapitalNormaluniversity,Beijing100037）1植物名称皇冠草（Echinoborusosiris）。2材料类别幼叶（长2～3cm）。3培养条件体胚诱导培养基：（1）MS＋ZT1mg／L（单位下同）＋6－BA1;（2）MS十ZT1＋6－BA1＋NAA0．5;（3）MS＋ZT1＋6－BA1＋NAA1。体胚萌发培养基：MS＋IAA1。以上培养基均含蔗糖30g／L,琼脂8g／L,PH5．8。光照度800lx,每天光照12h,于25℃恒温下培养。毛生长与分化情况叶片经常规…     

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.