液体培养的蛇足石杉离体叶状体生产石杉碱甲和生化特征研究

为了解浅层液体培养对蛇足石杉[Huperzia serrate (Thunb.) Trev.]叶状体的影响,采用不同用量培养液进行培养,对叶状体的生长、石杉碱甲(HupA)积累、抗氧化酶活性和内源激素的变化进行了研究。结果表明,培养液用量不同,叶状体产生的HupA含量有显著差异,15 mL浅层培养的HupA生产率可达3 115.159μg L–1,是对照的2.20倍。浅层液体培养的叶状体的超氧化物歧化酶活性始终高于对照,过氧化物酶活性在培养前期比对照提高,过氧化氢酶活性在培养后期比对照提高;内源激素IAA与GA含量低于对照,而ABA含量高于对照。因此,浅层液体培养的蛇足石杉离体叶状体生产HupA的能力更高,且HupA含量与内源激素ABA水平相关,叶状体生长期的3种抗氧化酶活性具有协作增强抗氧化作用。     

椭圆叶花锚种子内源激素对储藏的响应及其与种子萌发的关系

内源激素作为调控种子萌发与休眠的主要内因一直备受关注,但其随环境条件改变的变化规律及其对种子萌发的调节机制一直缺乏普遍接受的理论或假说。本研究以广泛分布于青藏高原东北缘高寒草甸的椭圆叶花锚种子为研究材料,分析不同储藏条件和时间对椭圆叶花锚种子内源激素含量的影响,及其与种子萌发的关系。结果表明:不同储藏条件下,椭圆叶花锚种子中内源激素含量随储藏时间变化差异显著;常温条件下,储藏时间对内源激素的绝对含量及各生长促进物与抑制物的比值(IAA/ABA除外)均有较显著的影响,而在冷藏条件下,储藏时间仅对GAs、IAA、ABA和促进物总量有较显著的影响;储藏条件和时间对椭圆叶花锚种子的萌发率均有极显著影响;常温储藏条件下种子萌发率大约是冷藏条件下的4倍,且种子存在休眠循环;椭圆叶花锚种子萌发并不是促进类激素或抑制类激素绝对含量的升降调节的;种子萌发与GAs含量显著正相关、与IAA含量显著负相关,CTK的含量达到一定高度的时候,萌发率才能达到最高。因此,本研究中各内源激素的作用关系,与Khan提出的三因子学说相一致,即CTK与ABA相拮抗,减轻或消除ABA的萌发抑制作用,从而使GAs的作用表现出来。     

石灰氮催芽对葡萄芽内源物质含量的影响(英文)

用15%石灰氮对巨峰葡萄(Kyoho grapevine)进行催芽后,于葡萄休眠解除过程中对芽内源激素含量、蛋白质含量以及淀粉酶活性的动态变化进行测定分析,以探讨石灰氮解除葡萄休眠的生理机制.结果显示:(1)用15%石灰氮催芽5 d后葡萄芽解除休眠而萌发,比对照提前5～8 d,处理21 d后休眠已经被打破;(2)处理后葡萄芽内ABA含量急剧下降了86.48%,而GA_3、ZR和IAA分别升高了461.70%、107.24%和1 020.41%;(3)IAA的急剧升高,伴随着淀粉酶活性加强,加速淀粉降解为可溶性糖;而蛋白质含量则先下降后升高.可见,石灰氮催芽后,葡萄芽内的生长抑制类激素ABA含量降低的同时生长促进类激素IAA、ZR和GA_3含量急剧增加,内源激素平衡被打破,加强了葡萄芽内有机物质的代谢,为葡萄芽的萌发提供了物质基础.因此,石灰氮处理促进葡萄休眠芽萌发的主要原因可能是调节了葡萄芽内各种激素平衡关系,从而加速了葡萄芽内有机物质的代谢而最终解除芽体休眠.     

南方红豆杉种子综合处理过程中内源激素的动态变化

为揭示南方红豆杉种子内源激素与休眠的关系,采用酶联免疫吸附法(ELISA)测定了经过层积处理的种皮和胚乳的脱落酸(ABA)、赤霉素(GA3 )、吲哚乙酸(IAA)、玉米素核苷(ZR)4种内源激素含量的变化情况.结果表明:种子胚乳中内源ABA的含量随着层积时间的延长而逐渐下降,GA含量增加,IAA和ZR的含量先增加后降低...     

南方砂梨返花过程中内源激素含量变化及其与秋季返花的关系

为探讨花芽内源激素含量变化与返花的关系,以砂梨品种‘丰水’、‘翠冠’为材料,研究了砂梨采果后返花过程中花芽内源激素(IAA、GA3、ABA)含量变化,以及早期落叶和秋季返花特征。结果表明:(1)在采果后至返花过程中,两个品种梨花芽中内源激素IAA和GA3含量都呈逐渐缓慢下降趋势;花芽ABA含量的动态变化成升-降-升的"S"曲线。(2)花芽返花受3种激素的动态平衡控制,花芽IAA/ABA、GA3/ABA和(IAA+GA3)/ABA值变化趋势均呈相似的"S"形曲线,IAA/ABA、GA3/ABA和(IAA+GA3)/ABA值增加,花芽返花;比值降低,花芽逐渐步入休眠期。(3)砂梨的落叶率与返花率呈极显著正相关关系,花芽中IAA/ABA比值与砂梨落叶率和返花率相关系数分别为0.805、0.774,相关性均达到显著水平。研究认为,梨返花与早期落叶密切相关,受花芽内源激素IAA、GA3、ABA动态平衡控制;早期落叶降低了花芽中ABA的含量,从而使花芽内生长促进型激素占主导地位,阻止自然休眠的花芽进入休眠或促使进入浅休眠部分花芽解除休眠,所以出现秋季返花现象。     

野生玫瑰果实发育过程中种子的细胞组织结构和内源激素变化对其休眠性的影响

以吉林珲春自然群落的野生玫瑰(Rosa rugosa Thunb.)为试验材料,探究野生玫瑰在果实形成过程中种子的发育及休眠性的形成和变化。选取青果期(1~35 d)、转色期(35~60 d)、红果期(60~75 d)的果实及种子,结合形态学、组织细胞学观察法及高效液相色谱技术,对果实各发育时期的种子形态、种胚及内果皮的发育进行研究,并分析种子内源激素含量变化与果实发育、种子休眠之间的关系。结果表明:果实和种子在青果期(1~35 d)时发育速度最快,种胚在花后24 d发育完全,种子不存在形态休眠。花后24 d内果皮开始沉积木质素并逐渐木质化,种子开始产生机械休眠。种子激素含量的变化与果实的发育、转色及内果皮的木质化密切相关,种子内源GA3和ABA含量在青果期(1~35 d)达到峰值,内源IAA含量在果实转色期(35~60 d)达到最大值,高浓度的ABA含量是种子尚未脱离果实时便已进入生理休眠的主要原因。     

外源激素对大豆种子内源ABA水平的影响及其和同化物积累的关系

用微注射法将ＩＡＡ、ＧＡ３、ＫＴ引入开花后３０ｄ的大豆（ＧｌｙｃｉｎｅｍａｘＬ．）完整植株种子的两片子叶之间,７ｄ后取样,分别测定了种皮和子叶中的ＡＢＡ含量、酸性转化酶和ＡＴＰ酶活性,同时分析了子叶中的糖和蛋白质含量的变化。结果表明：１０－６ｍｏｌ／ＬＩＡＡ和１０－６ｍｏｌ／Ｌ的ＫＴ处理使种皮中的ＡＢＡ水平升高,酸性转化酶活性提高,而ＡＴＰ酶活性降低;相反,对照子叶中的ＡＢＡ水平下降,酸性转化酶活性也下降,而ＡＴＰ酶活性显著提高;１０－６ｍｏｌ／ＬＧＡ３的作用正相反,使种皮和子叶中的ＡＢＡ水平均下降,酸性转化酶活性及子叶中的ＡＴＰ酶活性也相应下降,但种皮中的ＡＴＰ酶活性却上升;子叶中的糖和蛋白质含量的变化没有明确的规律。内源ＡＢＡ含量的变化与转化酶和ＡＴＰ酶活性变化呈现一定的相关关系,表明ＡＢＡ参与了调节大豆种子中的同化物积累。对外源激素对大豆种子内源ＡＢＡ水平的影响及其和同化物积累的关系进行了讨论。     

4种野生牡丹种子休眠和萌发特性及与其致濒的关系(英文)

与栽培牡丹相比,野生矮牡丹、四川牡丹和紫斑牡丹的种子一般较小,但野生黄牡丹种子则明显大于栽培牡丹。这４ 种濒危的野生牡丹种子的休眠与萌发特性与栽培牡丹的有明显差异：萌发生根期需半年以上,但通过胚培养可使之减至２ 周;萌发温度以１０～１５℃为宜, 超过２０℃则明显不利于生根及上胚轴生长; 打破上胚轴休眠需要严格的低温;野生牡丹种子的萌发率及打破上胚轴休眠后的出苗率也大大低于栽培牡丹,而且在不同分布地之间存在较大差异。实验证明：在自然状态下野生牡丹缺乏充分的传粉,特别是居群间的传粉不足,导致其种子质量低下;而野生牡丹种子特殊的萌发特性,特别是严格的上胚轴休眠,则是导致其出苗率极低及自然状态下幼苗和种群稀少的重要内因。生化测定结果表明：在低温打破牡丹种子上胚轴休眠过程中,子叶中的萌发促进剂ＧＡ３ 含量明显升高,抑制剂ＡＢＡ 含量显著下降;而胚乳中的各种激素含量则变化不大,胚轴中的激素变化无明显规律,因此认为子叶是控制牡丹种子上胚轴休眠的关键部位。     

表油菜素内酯对湿地松苗内源激素的影响（简报）

１－２ｍｇ／Ｌ表油菜素内酯（ＢＲ）处理,可提高湿地松苗内源ＩＡＡ、ＧＡ３、ＣＴＫ及ＡＢＡ的含量。采用ＳＥＰ－ＰＡＫ Ｃ１８柱纯化样品,ＨＰＬＣ法检测除乙烯以外的内源激素,效果好,操作简便。     

激素对植物细胞悬浮培养代谢产物的影响研究进展

激素是调节植物细胞生长发育和代谢产物形成的主要物质。综述了在植物细胞悬浮培养中,激素对细胞生物量和代谢产物含量的影响的研究进展。内容包括外源激素的种类、浓度、配比对悬浮培养细胞生物量和代谢产物含量的影响,内源激素检测技术的发展历程、内源激素的含量变化及其对悬浮培养细胞生物量和代谢产物含量的影响,内源激素和外源激素对植物细胞悬浮培养影响的相互作用关系以及新品种激素影响作用的相关研究。     

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.     

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细