新疆呼图壁种牛场地区13种优势植物水溶性盐分的含量特点及数量分析

通过对新疆呼图壁种牛场地区１３种耐盐植物水溶性盐分含量的分析,结果阐述了盐分分布和积累的特点：１）大部分植物在盐分含量水平上是：Ｎａ＾＋〉Ｋ＾＋〉Ｍｇ＾２＋〉Ｃａ＾２＋,Ｃｌ＾－〉ＳＯ４＾２－〉ＨＣＯ３＾－〉ＣＯ３＾２－,Ｎａ＾＋超过２００００μｇ／ｇ,Ｃａ＾２＋不足８００μｇ／ｇ;Ｃｌ＾－达４．１６％,ＣＯ３＾２－仅为０．１１％。全盐量平均为２５．８１％;２）ＣＯ３＾２－、ＨＣＯ３＾－和Ｃａ＾２     

酿酒酵母3——磷酸甘油脱氢酶的诱导,提纯和性质

在ＹＥＰＤ培养中添加ＮａＣｌ,可以诱导酿酒酵母细胞内３－磷酸甘油脱氢酶的形成,当ＮａＣｌ浓度达５％时,酶比活从０．０５Ｕ／ｍｇ提高到０．５Ｕ／ｍｇ;若再限制培养基中葡萄糖浓度在１００ｍｇ／Ｌ以下,酶比活可达到０．８９Ｕ／ｍｇ。酶比活与培养基中的ＮａＣｌ浓度的函数关系式为：Ｓａ＝０．１２９Ｃ＾３－０．０３８Ｃ＾２＋０．０３４Ｃ＋０．０６３。粗酶液经Ｓｅｐｈａｄｅｘ Ｇ－２５凝胶过滤,Ｂｌｕｅ Ｓｅｐ     

小麦耐盐细胞系耐盐性分析

通过一步筛选获得了耐盐（１．０％,ＮａＣｌ）的小麦（Ｔｒｉｔｉｃｕｍ ａｅｓｔｉｖｕｍ）细胞系（Ｓｒ１）,当ＳＲ１在含１．０％,ＮａＣｌ的培养基上继代半年后,钭其中的一部分移入无盐培养基代１０次,得到细胞系ＳＲ２。无论是在正常还是办迫条件下,ＳＲ１的鲜重增量／克鲜重、脯氨酸及可溶性蛋白含量均高于原始型（ＳＮ）,而含水量均高于原始型（ＳＮ）,而含水量、Ｋ＾＋及可溶性糖含量却低于ＳＮ。Ｎａ＾＋和Ｃｌ＾     

小麦耐盐细胞系及后代耐盐稳定性的生化分析

以离体培养筛选出的耐盐小麦变异系及其后代为材料,对其耐盐稳定性进行有关生理生化特性分析。结果表明：（１）随着耐盐愈伤组织耐盐能力的提高,过氧化物同工酶酶带谱加,与对照相比,三个区域出现了明显差异;（２）从耐盐愈伤组织酯酶同工酶酶谱发现,耐盐愈伤组织具有Ｃ２,Ｃ５,Ｃ９,Ｃ１１新增加酶带;（３）耐盐系后代幼苗能维持较高的Ｋ＾＋／Ｎａ＾＋比值,在盐浓度为０．９％时,其Ｋ＾＋／Ｎａ＾＋为０．７８８,而对     

钾抑制盐生植物生长的生理基础研究

盐生植物碱蓬中亚滨藜和补血草幼苗用不同浓度ＫＣｌ和等渗的ＮａＣｌ处理,结果表明,１００－５００和１００－４００ｍｍｏｌ／ＬＫＣｌ对它们的有面士重和净光合率产生明显抑制作用,证明Ｋ＾＋可抑制盐生植物生长并与光合速率降低有关。１００－４００ｍｍｏｌ／ＬＫＣｌ降低幼苗Ｎａ＾＋而增大Ｋ＾＋含量,对细胞渗透势和渗透调节能力基本不起作用,证明Ｋ＾＋抑制生长与植物体渗透调节物质Ｎａ＾＋不足以及高浓度的Ｋ＾＋对细     

盐分胁迫条件下甜菜碱对小麦幼苗体内Na^＋,K^＋和Cl^—的含量及 …

以抗盐品种茶淀红和盐敏感品种中国春等两种小麦为实验材料,研究甜菜碱对盐分胁迫条件下小麦幼苗Ｎａ＾＋、Ｋ＾＋、Ｃｌ＾－的吸收、分配的影响。结果表明：外源甜菜碱能够在一定程度上限制幼苗对Ｎａ＾＋、Ｋ＾＋、Ｃｌ＾－的吸收、分配的影响。结果表明：外源甜菜碱能够在一定程度上限制幼苗对Ｎａ＾＋、Ｃｌ＾－的吸收,阻滞其向地上部分运输的数量和速度,同时提高体内Ｋ＾＋含量、向上运输效率,降低地上部分对Ｎａ＾＋、Ｋ＾     

水分胁迫对小麦根质膜H^＋—ATPase活性与H^＋分泌的影响

在渗透势为－０．５和－１．０ＭＰａ ＰＥＧ处理下,不抗旱的郑引一号小麦根ＰＭＨ＾＋－－ＡＴＰａｓｅ活性分别为下降４５％和６５％,抗旱品种陕合六号则增加了１１％和１２％。小麦根组织Ｈ＾＋分泌与ＰＭＨ＾＋－ＡＴＰａｓｅ活性的变化趋势基本一致,即随着胁强增加,郑引一号Ｈ＾＋分泌下降,陕合六号Ｈ＾＋分泌是先升高后略降。Ｎａ３ＶＯ４和ＤＣＣＤ对Ｈ＾＋分泌有不同程度的抑制,品种之间没有明显的差异。外源电子受体     

盐胁迫下Ca^2＋对小麦根无机离子分布和膜脂脂肪酸的影响

用扫描电镜、Ｘ－射线能谱仪和等离子耦合吸收光谱分析发现,培养在含ＮａＣｌ培养液中,小麦根吸收大量Ｎａ＾＋和Ｃｌ＾－,Ｋ＾＋和Ｃａ＾２＋的吸收降低、质膜相对透性提高,Ｋ＾＋,Ｎａ＾＋和Ｃｌ＾－的相对外渗百分率增加,培养在补充ＣａＣｌ２含ＮａＣｌ培养液的,Ｎａ＾＋和Ｃｌ＾－含量明显减低,Ｋ＾＋和Ｃａ＾２＋提高,质膜相对透性下降,Ｋ＾＋,Ｎａ＾＋和Ｃｌ＾－相对外渗百分率减少。由气相色谱分析可知,用含Ｎａ     

NaCl胁迫对小麦抗盐突变体根液包膜H^＋—ATP酶和H^＋—PP酶活性的影响

随着盐胁迫强度（ＮａＣｌ０～１５０ｍｍｏｌ／Ｌ）和时间（０～７２ｈ）的增加,小麦抗盐突变体根液泡膜Ｈ＾＋－ＡＴＰ酶和Ｈ＾＋－ＰＰ酶活性显著增加,虽然野生型酶活性在盐胁迫下也有增加,但其增加的幅度显著低于突变体,Ｈ＾＋－ＰＰ酶活性的差异更为显著。Ｈ＾＋－ＡＴＰ酶和Ｈ＾＋－ＰＰ酶的最适ｐＨ值在两者之间以及盐胁迫前后均无改变,分别为７．０和８．０。无盐胁迫下野生型液胞泡５８ｋＤ蛋白带缺失,盐胁迫下这一蛋     

小麦耐盐细胞系对盐胁迫的伤害性反应

通过逐级提高ＮａＣｌ浓度的筛选方法,得到了能在１．５％ＮａＣｌ下生长良好的小麦（ＴｒｉｔｉｃｕｍａｅｓｔｉｖｕｍＬ．）耐盐细胞系。在盐分胁迫下,耐盐细胞系含水量的降低幅度小于不耐盐细胞系（对照）,Ｈ２Ｏ２含量和Ｏ－２产生速率的增加幅度也明显小于对照细胞系。同时,膜的相对透性、膜脂过氧化和脱酯化程度的提高幅度也明显低于对照细胞系。表明盐分对小麦细胞系膜的伤害与活性氧介导的膜脂过氧化和脱酯化有关,而耐盐细胞系比对照细胞系表现出较强的抗活性氧伤害的能力。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.